diff options
| author | Rémi Verschelde <rverschelde@gmail.com> | 2016-10-09 23:36:17 +0200 |
|---|---|---|
| committer | Rémi Verschelde <rverschelde@gmail.com> | 2016-10-15 11:50:39 +0200 |
| commit | 5fef84a1358310304cb1114924525ec4df794b49 (patch) | |
| tree | 0ccafa62380328af528d3f11fb144b4a3fd933f3 /thirdparty/libpng | |
| parent | 17f06202b7d5e00b6bf250e03b0ca994ee5dd298 (diff) | |
png: Split library to thirdparty dir and allow unbundling
Uses the new structure agreed upon in #6157, but the thirdparty/ folder
does not behave following a logic similar to that of modules/ yet.
The png driver can't be moved to a module as discussed in #6157, as it's
required by core together with a few other ImageLoader implementations
(see drivers/register_driver_types.cpp:register_core_driver_types())
Dropped the possibility to disable PNG support, it's a core component
of Godot.
Diffstat (limited to 'thirdparty/libpng')
26 files changed, 38036 insertions, 0 deletions
diff --git a/thirdparty/libpng/LICENSE b/thirdparty/libpng/LICENSE new file mode 100644 index 0000000000..b7ad4b9eaf --- /dev/null +++ b/thirdparty/libpng/LICENSE @@ -0,0 +1,130 @@ + +This copy of the libpng notices is provided for your convenience. In case of +any discrepancy between this copy and the notices in the file png.h that is +included in the libpng distribution, the latter shall prevail. + +COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: + +If you modify libpng you may insert additional notices immediately following +this sentence. + +This code is released under the libpng license. + +libpng versions 1.0.7, July 1, 2000 through 1.6.23, June 9, 2016 are +Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are +derived from libpng-1.0.6, and are distributed according to the same +disclaimer and license as libpng-1.0.6 with the following individuals +added to the list of Contributing Authors: + + Simon-Pierre Cadieux + Eric S. Raymond + Mans Rullgard + Cosmin Truta + Gilles Vollant + James Yu + +and with the following additions to the disclaimer: + + There is no warranty against interference with your enjoyment of the + library or against infringement. There is no warranty that our + efforts or the library will fulfill any of your particular purposes + or needs. This library is provided with all faults, and the entire + risk of satisfactory quality, performance, accuracy, and effort is with + the user. + +Some files in the "contrib" directory and some configure-generated +files that are distributed with libpng have other copyright owners and +are released under other open source licenses. + +libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are +Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from +libpng-0.96, and are distributed according to the same disclaimer and +license as libpng-0.96, with the following individuals added to the list +of Contributing Authors: + + Tom Lane + Glenn Randers-Pehrson + Willem van Schaik + +libpng versions 0.89, June 1996, through 0.96, May 1997, are +Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, +and are distributed according to the same disclaimer and license as +libpng-0.88, with the following individuals added to the list of +Contributing Authors: + + John Bowler + Kevin Bracey + Sam Bushell + Magnus Holmgren + Greg Roelofs + Tom Tanner + +Some files in the "scripts" directory have other copyright owners +but are released under this license. + +libpng versions 0.5, May 1995, through 0.88, January 1996, are +Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + +For the purposes of this copyright and license, "Contributing Authors" +is defined as the following set of individuals: + + Andreas Dilger + Dave Martindale + Guy Eric Schalnat + Paul Schmidt + Tim Wegner + +The PNG Reference Library is supplied "AS IS". The Contributing Authors +and Group 42, Inc. disclaim all warranties, expressed or implied, +including, without limitation, the warranties of merchantability and of +fitness for any purpose. The Contributing Authors and Group 42, Inc. +assume no liability for direct, indirect, incidental, special, exemplary, +or consequential damages, which may result from the use of the PNG +Reference Library, even if advised of the possibility of such damage. + +Permission is hereby granted to use, copy, modify, and distribute this +source code, or portions hereof, for any purpose, without fee, subject +to the following restrictions: + + 1. The origin of this source code must not be misrepresented. + + 2. Altered versions must be plainly marked as such and must not + be misrepresented as being the original source. + + 3. This Copyright notice may not be removed or altered from any + source or altered source distribution. + +The Contributing Authors and Group 42, Inc. specifically permit, without +fee, and encourage the use of this source code as a component to +supporting the PNG file format in commercial products. If you use this +source code in a product, acknowledgment is not required but would be +appreciated. + +END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. + +TRADEMARK: + +The name "libpng" has not been registered by the Copyright owner +as a trademark in any jurisdiction. However, because libpng has +been distributed and maintained world-wide, continually since 1995, +the Copyright owner claims "common-law trademark protection" in any +jurisdiction where common-law trademark is recognized. + +OSI CERTIFICATION: + +Libpng is OSI Certified Open Source Software. OSI Certified Open Source is +a certification mark of the Open Source Initiative. OSI has not addressed +the additional disclaimers inserted at version 1.0.7. + +EXPORT CONTROL: + +The Copyright owner believes that the Export Control Classification +Number (ECCN) for libpng is EAR99, which means not subject to export +controls or International Traffic in Arms Regulations (ITAR) because +it is open source, publicly available software, that does not contain +any encryption software. See the EAR, paragraphs 734.3(b)(3) and +734.7(b). + +Glenn Randers-Pehrson +glennrp at users.sourceforge.net +June 9, 2016 diff --git a/thirdparty/libpng/arm/arm_init.c b/thirdparty/libpng/arm/arm_init.c new file mode 100644 index 0000000000..52c3f31fed --- /dev/null +++ b/thirdparty/libpng/arm/arm_init.c @@ -0,0 +1,135 @@ + +/* arm_init.c - NEON optimised filter functions + * + * Copyright (c) 2014,2016 Glenn Randers-Pehrson + * Written by Mans Rullgard, 2011. + * Last changed in libpng 1.6.22 [June 9, 2016] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ +/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are + * called. + */ +#define _POSIX_SOURCE 1 + +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#if PNG_ARM_NEON_OPT > 0 +#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */ +/* WARNING: it is strongly recommended that you do not build libpng with + * run-time checks for CPU features if at all possible. In the case of the ARM + * NEON instructions there is no processor-specific way of detecting the + * presence of the required support, therefore run-time detection is extremely + * OS specific. + * + * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing + * a fragment of C source code which defines the png_have_neon function. There + * are a number of implementations in contrib/arm-neon, but the only one that + * has partial support is contrib/arm-neon/linux.c - a generic Linux + * implementation which reads /proc/cpufino. + */ +#ifndef PNG_ARM_NEON_FILE +# ifdef __linux__ +# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c" +# endif +#endif + +#ifdef PNG_ARM_NEON_FILE + +#include <signal.h> /* for sig_atomic_t */ +static int png_have_neon(png_structp png_ptr); +#include PNG_ARM_NEON_FILE + +#else /* PNG_ARM_NEON_FILE */ +# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks" +#endif /* PNG_ARM_NEON_FILE */ +#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ + +#ifndef PNG_ALIGNED_MEMORY_SUPPORTED +# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED" +#endif + +void +png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +{ + /* The switch statement is compiled in for ARM_NEON_API, the call to + * png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined + * the check is only performed if the API has not set the NEON option on + * or off explicitly. In this case the check controls what happens. + * + * If the CHECK is not compiled in and the option is UNSET the behavior prior + * to 1.6.7 was to use the NEON code - this was a bug caused by having the + * wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF, + * as documented in png.h + */ + png_debug(1, "in png_init_filter_functions_neon"); +#ifdef PNG_ARM_NEON_API_SUPPORTED + switch ((pp->options >> PNG_ARM_NEON) & 3) + { + case PNG_OPTION_UNSET: + /* Allow the run-time check to execute if it has been enabled - + * thus both API and CHECK can be turned on. If it isn't supported + * this case will fall through to the 'default' below, which just + * returns. + */ +#endif /* PNG_ARM_NEON_API_SUPPORTED */ +#ifdef PNG_ARM_NEON_CHECK_SUPPORTED + { + static volatile sig_atomic_t no_neon = -1; /* not checked */ + + if (no_neon < 0) + no_neon = !png_have_neon(pp); + + if (no_neon) + return; + } +#ifdef PNG_ARM_NEON_API_SUPPORTED + break; +#endif +#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ + +#ifdef PNG_ARM_NEON_API_SUPPORTED + default: /* OFF or INVALID */ + return; + + case PNG_OPTION_ON: + /* Option turned on */ + break; + } +#endif + + /* IMPORTANT: any new external functions used here must be declared using + * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the + * 'prefix' option to configure works: + * + * ./configure --with-libpng-prefix=foobar_ + * + * Verify you have got this right by running the above command, doing a build + * and examining pngprefix.h; it must contain a #define for every external + * function you add. (Notice that this happens automatically for the + * initialization function.) + */ + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_neon; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_neon; + } +} +#endif /* PNG_ARM_NEON_OPT > 0 */ +#endif /* READ */ diff --git a/thirdparty/libpng/arm/filter_neon.S b/thirdparty/libpng/arm/filter_neon.S new file mode 100644 index 0000000000..3b061d6bbf --- /dev/null +++ b/thirdparty/libpng/arm/filter_neon.S @@ -0,0 +1,253 @@ + +/* filter_neon.S - NEON optimised filter functions + * + * Copyright (c) 2014 Glenn Randers-Pehrson + * Written by Mans Rullgard, 2011. + * Last changed in libpng 1.6.16 [December 22, 2014] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* This is required to get the symbol renames, which are #defines, and the + * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION. + */ +#define PNG_VERSION_INFO_ONLY +#include "../pngpriv.h" + +#if defined(__linux__) && defined(__ELF__) +.section .note.GNU-stack,"",%progbits /* mark stack as non-executable */ +#endif + +#ifdef PNG_READ_SUPPORTED + +/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for + * ARM64). The code in arm/filter_neon_intrinsics.c supports ARM64, however it + * only works if -mfpu=neon is specified on the GCC command line. See pngpriv.h + * for the logic which sets PNG_USE_ARM_NEON_ASM: + */ +#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */ + +#if PNG_ARM_NEON_OPT > 0 + +#ifdef __ELF__ +# define ELF +#else +# define ELF @ +#endif + + .arch armv7-a + .fpu neon + +.macro func name, export=0 + .macro endfunc +ELF .size \name, . - \name + .endfunc + .purgem endfunc + .endm + .text + + /* Explicitly specifying alignment here because some versions of + * GAS don't align code correctly. This is harmless in correctly + * written versions of GAS. + */ + .align 2 + + .if \export + .global \name + .endif +ELF .type \name, STT_FUNC + .func \name +\name: +.endm + +func png_read_filter_row_sub4_neon, export=1 + ldr r3, [r0, #4] @ rowbytes + vmov.i8 d3, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vadd.u8 d0, d3, d4 + vadd.u8 d1, d0, d5 + vadd.u8 d2, d1, d6 + vadd.u8 d3, d2, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r3, r3, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_sub3_neon, export=1 + ldr r3, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + mov r0, r1 + mov r2, #3 + mov r12, #12 + vld1.8 {q11}, [r0], r12 +1: + vext.8 d5, d22, d23, #3 + vadd.u8 d0, d3, d22 + vext.8 d6, d22, d23, #6 + vadd.u8 d1, d0, d5 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], r12 + vst1.32 {d0[0]}, [r1,:32], r2 + vadd.u8 d2, d1, d6 + vst1.32 {d1[0]}, [r1], r2 + vadd.u8 d3, d2, d7 + vst1.32 {d2[0]}, [r1], r2 + vst1.32 {d3[0]}, [r1], r2 + subs r3, r3, #12 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_up_neon, export=1 + ldr r3, [r0, #4] @ rowbytes +1: + vld1.8 {q0}, [r1,:128] + vld1.8 {q1}, [r2,:128]! + vadd.u8 q0, q0, q1 + vst1.8 {q0}, [r1,:128]! + subs r3, r3, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_avg4_neon, export=1 + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! + vhadd.u8 d0, d3, d16 + vadd.u8 d0, d0, d4 + vhadd.u8 d1, d0, d17 + vadd.u8 d1, d1, d5 + vhadd.u8 d2, d1, d18 + vadd.u8 d2, d2, d6 + vhadd.u8 d3, d2, d19 + vadd.u8 d3, d3, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r12, r12, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_avg3_neon, export=1 + push {r4,lr} + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + mov r0, r1 + mov r4, #3 + mov lr, #12 + vld1.8 {q11}, [r0], lr +1: + vld1.8 {q10}, [r2], lr + vext.8 d5, d22, d23, #3 + vhadd.u8 d0, d3, d20 + vext.8 d17, d20, d21, #3 + vadd.u8 d0, d0, d22 + vext.8 d6, d22, d23, #6 + vhadd.u8 d1, d0, d17 + vext.8 d18, d20, d21, #6 + vadd.u8 d1, d1, d5 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], lr + vst1.32 {d0[0]}, [r1,:32], r4 + vhadd.u8 d2, d1, d18 + vst1.32 {d1[0]}, [r1], r4 + vext.8 d19, d21, d21, #1 + vadd.u8 d2, d2, d6 + vhadd.u8 d3, d2, d19 + vst1.32 {d2[0]}, [r1], r4 + vadd.u8 d3, d3, d7 + vst1.32 {d3[0]}, [r1], r4 + subs r12, r12, #12 + bgt 1b + + pop {r4,pc} +endfunc + +.macro paeth rx, ra, rb, rc + vaddl.u8 q12, \ra, \rb @ a + b + vaddl.u8 q15, \rc, \rc @ 2*c + vabdl.u8 q13, \rb, \rc @ pa + vabdl.u8 q14, \ra, \rc @ pb + vabd.u16 q15, q12, q15 @ pc + vcle.u16 q12, q13, q14 @ pa <= pb + vcle.u16 q13, q13, q15 @ pa <= pc + vcle.u16 q14, q14, q15 @ pb <= pc + vand q12, q12, q13 @ pa <= pb && pa <= pc + vmovn.u16 d28, q14 + vmovn.u16 \rx, q12 + vbsl d28, \rb, \rc + vbsl \rx, \ra, d28 +.endm + +func png_read_filter_row_paeth4_neon, export=1 + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + vmov.i8 d20, #0 +1: + vld4.32 {d4[],d5[],d6[],d7[]}, [r1,:128] + vld4.32 {d16[],d17[],d18[],d19[]},[r2,:128]! + paeth d0, d3, d16, d20 + vadd.u8 d0, d0, d4 + paeth d1, d0, d17, d16 + vadd.u8 d1, d1, d5 + paeth d2, d1, d18, d17 + vadd.u8 d2, d2, d6 + paeth d3, d2, d19, d18 + vmov d20, d19 + vadd.u8 d3, d3, d7 + vst4.32 {d0[0],d1[0],d2[0],d3[0]},[r1,:128]! + subs r12, r12, #16 + bgt 1b + + bx lr +endfunc + +func png_read_filter_row_paeth3_neon, export=1 + push {r4,lr} + ldr r12, [r0, #4] @ rowbytes + vmov.i8 d3, #0 + vmov.i8 d4, #0 + mov r0, r1 + mov r4, #3 + mov lr, #12 + vld1.8 {q11}, [r0], lr +1: + vld1.8 {q10}, [r2], lr + paeth d0, d3, d20, d4 + vext.8 d5, d22, d23, #3 + vadd.u8 d0, d0, d22 + vext.8 d17, d20, d21, #3 + paeth d1, d0, d17, d20 + vst1.32 {d0[0]}, [r1,:32], r4 + vext.8 d6, d22, d23, #6 + vadd.u8 d1, d1, d5 + vext.8 d18, d20, d21, #6 + paeth d2, d1, d18, d17 + vext.8 d7, d23, d23, #1 + vld1.8 {q11}, [r0], lr + vst1.32 {d1[0]}, [r1], r4 + vadd.u8 d2, d2, d6 + vext.8 d19, d21, d21, #1 + paeth d3, d2, d19, d18 + vst1.32 {d2[0]}, [r1], r4 + vmov d4, d19 + vadd.u8 d3, d3, d7 + vst1.32 {d3[0]}, [r1], r4 + subs r12, r12, #12 + bgt 1b + + pop {r4,pc} +endfunc +#endif /* PNG_ARM_NEON_OPT > 0 */ +#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */ +#endif /* READ */ diff --git a/thirdparty/libpng/arm/filter_neon_intrinsics.c b/thirdparty/libpng/arm/filter_neon_intrinsics.c new file mode 100644 index 0000000000..be5ccc7107 --- /dev/null +++ b/thirdparty/libpng/arm/filter_neon_intrinsics.c @@ -0,0 +1,387 @@ + +/* filter_neon_intrinsics.c - NEON optimised filter functions + * + * Copyright (c) 2014,2016 Glenn Randers-Pehrson + * Written by James Yu <james.yu at linaro.org>, October 2013. + * Based on filter_neon.S, written by Mans Rullgard, 2011. + * + * Last changed in libpng 1.6.22 [June 9, 2016] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* This code requires -mfpu=neon on the command line: */ +#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */ + +#include <arm_neon.h> + +/* libpng row pointers are not necessarily aligned to any particular boundary, + * however this code will only work with appropriate alignment. arm/arm_init.c + * checks for this (and will not compile unless it is done). This code uses + * variants of png_aligncast to avoid compiler warnings. + */ +#define png_ptr(type,pointer) png_aligncast(type *,pointer) +#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer) + +/* The following relies on a variable 'temp_pointer' being declared with type + * 'type'. This is written this way just to hide the GCC strict aliasing + * warning; note that the code is safe because there never is an alias between + * the input and output pointers. + */ +#define png_ldr(type,pointer)\ + (temp_pointer = png_ptr(type,pointer), *temp_pointer) + +#if PNG_ARM_NEON_OPT > 0 + +void +png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + png_const_bytep pp = prev_row; + + png_debug(1, "in png_read_filter_row_up_neon"); + + for (; rp < rp_stop; rp += 16, pp += 16) + { + uint8x16_t qrp, qpp; + + qrp = vld1q_u8(rp); + qpp = vld1q_u8(pp); + qrp = vaddq_u8(qrp, qpp); + vst1q_u8(rp, qrp); + } +} + +void +png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x16_t vtmp = vld1q_u8(rp); + uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp); + uint8x8x2_t vrp = *vrpt; + + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_sub3_neon"); + + for (; rp < rp_stop;) + { + uint8x8_t vtmp1, vtmp2; + uint32x2_t *temp_pointer; + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); + vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]); + vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6); + vdest.val[1] = vadd_u8(vdest.val[0], vtmp1); + + vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); + vdest.val[2] = vadd_u8(vdest.val[1], vtmp2); + vdest.val[3] = vadd_u8(vdest.val[2], vtmp1); + + vtmp = vld1q_u8(rp + 12); + vrpt = png_ptr(uint8x8x2_t, &vtmp); + vrp = *vrpt; + + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); + rp += 3; + } + + PNG_UNUSED(prev_row) +} + +void +png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_sub4_neon"); + + for (; rp < rp_stop; rp += 16) + { + uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp)); + uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp); + uint8x8x4_t vrp = *vrpt; + uint32x2x4_t *temp_pointer; + + vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]); + vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]); + vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]); + vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]); + vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0); + } + + PNG_UNUSED(prev_row) +} + +void +png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_const_bytep pp = prev_row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x16_t vtmp; + uint8x8x2_t *vrpt; + uint8x8x2_t vrp; + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + vtmp = vld1q_u8(rp); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + png_debug(1, "in png_read_filter_row_avg3_neon"); + + for (; rp < rp_stop; pp += 12) + { + uint8x8_t vtmp1, vtmp2, vtmp3; + + uint8x8x2_t *vppt; + uint8x8x2_t vpp; + + uint32x2_t *temp_pointer; + + vtmp = vld1q_u8(pp); + vppt = png_ptr(uint8x8x2_t,&vtmp); + vpp = *vppt; + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); + vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + + vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3); + vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6); + vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2); + vdest.val[1] = vadd_u8(vdest.val[1], vtmp1); + + vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6); + vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); + + vtmp = vld1q_u8(rp + 12); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2); + vdest.val[2] = vadd_u8(vdest.val[2], vtmp3); + + vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1); + + vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2); + vdest.val[3] = vadd_u8(vdest.val[3], vtmp1); + + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); + rp += 3; + } +} + +void +png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + png_const_bytep pp = prev_row; + + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_avg4_neon"); + + for (; rp < rp_stop; rp += 16, pp += 16) + { + uint32x2x4_t vtmp; + uint8x8x4_t *vrpt, *vppt; + uint8x8x4_t vrp, vpp; + uint32x2x4_t *temp_pointer; + + vtmp = vld4_u32(png_ptr(uint32_t,rp)); + vrpt = png_ptr(uint8x8x4_t,&vtmp); + vrp = *vrpt; + vtmp = vld4_u32(png_ptrc(uint32_t,pp)); + vppt = png_ptr(uint8x8x4_t,&vtmp); + vpp = *vppt; + + vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]); + vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]); + vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]); + vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]); + vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]); + vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]); + + vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0); + } +} + +static uint8x8_t +paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c) +{ + uint8x8_t d, e; + uint16x8_t p1, pa, pb, pc; + + p1 = vaddl_u8(a, b); /* a + b */ + pc = vaddl_u8(c, c); /* c * 2 */ + pa = vabdl_u8(b, c); /* pa */ + pb = vabdl_u8(a, c); /* pb */ + pc = vabdq_u16(p1, pc); /* pc */ + + p1 = vcleq_u16(pa, pb); /* pa <= pb */ + pa = vcleq_u16(pa, pc); /* pa <= pc */ + pb = vcleq_u16(pb, pc); /* pb <= pc */ + + p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */ + + d = vmovn_u16(pb); + e = vmovn_u16(p1); + + d = vbsl_u8(d, b, c); + e = vbsl_u8(e, a, d); + + return e; +} + +void +png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_const_bytep pp = prev_row; + png_bytep rp_stop = row + row_info->rowbytes; + + uint8x16_t vtmp; + uint8x8x2_t *vrpt; + uint8x8x2_t vrp; + uint8x8_t vlast = vdup_n_u8(0); + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + vtmp = vld1q_u8(rp); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + png_debug(1, "in png_read_filter_row_paeth3_neon"); + + for (; rp < rp_stop; pp += 12) + { + uint8x8x2_t *vppt; + uint8x8x2_t vpp; + uint8x8_t vtmp1, vtmp2, vtmp3; + uint32x2_t *temp_pointer; + + vtmp = vld1q_u8(pp); + vppt = png_ptr(uint8x8x2_t,&vtmp); + vpp = *vppt; + + vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3); + vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3); + vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]); + vdest.val[1] = vadd_u8(vdest.val[1], vtmp1); + + vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6); + vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6); + vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2); + vdest.val[2] = vadd_u8(vdest.val[2], vtmp1); + + vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1); + vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1); + + vtmp = vld1q_u8(rp + 12); + vrpt = png_ptr(uint8x8x2_t,&vtmp); + vrp = *vrpt; + + vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3); + vdest.val[3] = vadd_u8(vdest.val[3], vtmp1); + + vlast = vtmp2; + + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0); + rp += 3; + vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0); + rp += 3; + } +} + +void +png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp = row; + png_bytep rp_stop = row + row_info->rowbytes; + png_const_bytep pp = prev_row; + + uint8x8_t vlast = vdup_n_u8(0); + uint8x8x4_t vdest; + vdest.val[3] = vdup_n_u8(0); + + png_debug(1, "in png_read_filter_row_paeth4_neon"); + + for (; rp < rp_stop; rp += 16, pp += 16) + { + uint32x2x4_t vtmp; + uint8x8x4_t *vrpt, *vppt; + uint8x8x4_t vrp, vpp; + uint32x2x4_t *temp_pointer; + + vtmp = vld4_u32(png_ptr(uint32_t,rp)); + vrpt = png_ptr(uint8x8x4_t,&vtmp); + vrp = *vrpt; + vtmp = vld4_u32(png_ptrc(uint32_t,pp)); + vppt = png_ptr(uint8x8x4_t,&vtmp); + vpp = *vppt; + + vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast); + vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]); + vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]); + vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]); + vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]); + vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]); + vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]); + vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]); + + vlast = vpp.val[3]; + + vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0); + } +} + +#endif /* PNG_ARM_NEON_OPT > 0 */ +#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */ +#endif /* READ */ diff --git a/thirdparty/libpng/png.c b/thirdparty/libpng/png.c new file mode 100644 index 0000000000..1720ca0eae --- /dev/null +++ b/thirdparty/libpng/png.c @@ -0,0 +1,4499 @@ + +/* png.c - location for general purpose libpng functions + * + * Last changed in libpng 1.6.19 [November 12, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +/* Generate a compiler error if there is an old png.h in the search path. */ +typedef png_libpng_version_1_6_23 Your_png_h_is_not_version_1_6_23; + +/* Tells libpng that we have already handled the first "num_bytes" bytes + * of the PNG file signature. If the PNG data is embedded into another + * stream we can set num_bytes = 8 so that libpng will not attempt to read + * or write any of the magic bytes before it starts on the IHDR. + */ + +#ifdef PNG_READ_SUPPORTED +void PNGAPI +png_set_sig_bytes(png_structrp png_ptr, int num_bytes) +{ + unsigned int nb = (unsigned int)num_bytes; + + png_debug(1, "in png_set_sig_bytes"); + + if (png_ptr == NULL) + return; + + if (num_bytes < 0) + nb = 0; + + if (nb > 8) + png_error(png_ptr, "Too many bytes for PNG signature"); + + png_ptr->sig_bytes = (png_byte)nb; +} + +/* Checks whether the supplied bytes match the PNG signature. We allow + * checking less than the full 8-byte signature so that those apps that + * already read the first few bytes of a file to determine the file type + * can simply check the remaining bytes for extra assurance. Returns + * an integer less than, equal to, or greater than zero if sig is found, + * respectively, to be less than, to match, or be greater than the correct + * PNG signature (this is the same behavior as strcmp, memcmp, etc). + */ +int PNGAPI +png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check) +{ + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + + if (num_to_check > 8) + num_to_check = 8; + + else if (num_to_check < 1) + return (-1); + + if (start > 7) + return (-1); + + if (start + num_to_check > 8) + num_to_check = 8 - start; + + return ((int)(memcmp(&sig[start], &png_signature[start], num_to_check))); +} + +#endif /* READ */ + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +/* Function to allocate memory for zlib */ +PNG_FUNCTION(voidpf /* PRIVATE */, +png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED) +{ + png_alloc_size_t num_bytes = size; + + if (png_ptr == NULL) + return NULL; + + if (items >= (~(png_alloc_size_t)0)/size) + { + png_warning (png_voidcast(png_structrp, png_ptr), + "Potential overflow in png_zalloc()"); + return NULL; + } + + num_bytes *= items; + return png_malloc_warn(png_voidcast(png_structrp, png_ptr), num_bytes); +} + +/* Function to free memory for zlib */ +void /* PRIVATE */ +png_zfree(voidpf png_ptr, voidpf ptr) +{ + png_free(png_voidcast(png_const_structrp,png_ptr), ptr); +} + +/* Reset the CRC variable to 32 bits of 1's. Care must be taken + * in case CRC is > 32 bits to leave the top bits 0. + */ +void /* PRIVATE */ +png_reset_crc(png_structrp png_ptr) +{ + /* The cast is safe because the crc is a 32-bit value. */ + png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0); +} + +/* Calculate the CRC over a section of data. We can only pass as + * much data to this routine as the largest single buffer size. We + * also check that this data will actually be used before going to the + * trouble of calculating it. + */ +void /* PRIVATE */ +png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, png_size_t length) +{ + int need_crc = 1; + + if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0) + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + + else /* critical */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0) + need_crc = 0; + } + + /* 'uLong' is defined in zlib.h as unsigned long; this means that on some + * systems it is a 64-bit value. crc32, however, returns 32 bits so the + * following cast is safe. 'uInt' may be no more than 16 bits, so it is + * necessary to perform a loop here. + */ + if (need_crc != 0 && length > 0) + { + uLong crc = png_ptr->crc; /* Should never issue a warning */ + + do + { + uInt safe_length = (uInt)length; +#ifndef __COVERITY__ + if (safe_length == 0) + safe_length = (uInt)-1; /* evil, but safe */ +#endif + + crc = crc32(crc, ptr, safe_length); + + /* The following should never issue compiler warnings; if they do the + * target system has characteristics that will probably violate other + * assumptions within the libpng code. + */ + ptr += safe_length; + length -= safe_length; + } + while (length > 0); + + /* And the following is always safe because the crc is only 32 bits. */ + png_ptr->crc = (png_uint_32)crc; + } +} + +/* Check a user supplied version number, called from both read and write + * functions that create a png_struct. + */ +int +png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver) +{ + /* Libpng versions 1.0.0 and later are binary compatible if the version + * string matches through the second '.'; we must recompile any + * applications that use any older library version. + */ + + if (user_png_ver != NULL) + { + int i = -1; + int found_dots = 0; + + do + { + i++; + if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i]) + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + if (user_png_ver[i] == '.') + found_dots++; + } while (found_dots < 2 && user_png_ver[i] != 0 && + PNG_LIBPNG_VER_STRING[i] != 0); + } + + else + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + + if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0) + { +#ifdef PNG_WARNINGS_SUPPORTED + size_t pos = 0; + char m[128]; + + pos = png_safecat(m, (sizeof m), pos, + "Application built with libpng-"); + pos = png_safecat(m, (sizeof m), pos, user_png_ver); + pos = png_safecat(m, (sizeof m), pos, " but running with "); + pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING); + PNG_UNUSED(pos) + + png_warning(png_ptr, m); +#endif + +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags = 0; +#endif + + return 0; + } + + /* Success return. */ + return 1; +} + +/* Generic function to create a png_struct for either read or write - this + * contains the common initialization. + */ +PNG_FUNCTION(png_structp /* PRIVATE */, +png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ + png_struct create_struct; +# ifdef PNG_SETJMP_SUPPORTED + jmp_buf create_jmp_buf; +# endif + + /* This temporary stack-allocated structure is used to provide a place to + * build enough context to allow the user provided memory allocator (if any) + * to be called. + */ + memset(&create_struct, 0, (sizeof create_struct)); + + /* Added at libpng-1.2.6 */ +# ifdef PNG_USER_LIMITS_SUPPORTED + create_struct.user_width_max = PNG_USER_WIDTH_MAX; + create_struct.user_height_max = PNG_USER_HEIGHT_MAX; + +# ifdef PNG_USER_CHUNK_CACHE_MAX + /* Added at libpng-1.2.43 and 1.4.0 */ + create_struct.user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX; +# endif + +# ifdef PNG_USER_CHUNK_MALLOC_MAX + /* Added at libpng-1.2.43 and 1.4.1, required only for read but exists + * in png_struct regardless. + */ + create_struct.user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX; +# endif +# endif + + /* The following two API calls simply set fields in png_struct, so it is safe + * to do them now even though error handling is not yet set up. + */ +# ifdef PNG_USER_MEM_SUPPORTED + png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn); +# else + PNG_UNUSED(mem_ptr) + PNG_UNUSED(malloc_fn) + PNG_UNUSED(free_fn) +# endif + + /* (*error_fn) can return control to the caller after the error_ptr is set, + * this will result in a memory leak unless the error_fn does something + * extremely sophisticated. The design lacks merit but is implicit in the + * API. + */ + png_set_error_fn(&create_struct, error_ptr, error_fn, warn_fn); + +# ifdef PNG_SETJMP_SUPPORTED + if (!setjmp(create_jmp_buf)) +# endif + { +# ifdef PNG_SETJMP_SUPPORTED + /* Temporarily fake out the longjmp information until we have + * successfully completed this function. This only works if we have + * setjmp() support compiled in, but it is safe - this stuff should + * never happen. + */ + create_struct.jmp_buf_ptr = &create_jmp_buf; + create_struct.jmp_buf_size = 0; /*stack allocation*/ + create_struct.longjmp_fn = longjmp; +# endif + /* Call the general version checker (shared with read and write code): + */ + if (png_user_version_check(&create_struct, user_png_ver) != 0) + { + png_structrp png_ptr = png_voidcast(png_structrp, + png_malloc_warn(&create_struct, (sizeof *png_ptr))); + + if (png_ptr != NULL) + { + /* png_ptr->zstream holds a back-pointer to the png_struct, so + * this can only be done now: + */ + create_struct.zstream.zalloc = png_zalloc; + create_struct.zstream.zfree = png_zfree; + create_struct.zstream.opaque = png_ptr; + +# ifdef PNG_SETJMP_SUPPORTED + /* Eliminate the local error handling: */ + create_struct.jmp_buf_ptr = NULL; + create_struct.jmp_buf_size = 0; + create_struct.longjmp_fn = 0; +# endif + + *png_ptr = create_struct; + + /* This is the successful return point */ + return png_ptr; + } + } + } + + /* A longjmp because of a bug in the application storage allocator or a + * simple failure to allocate the png_struct. + */ + return NULL; +} + +/* Allocate the memory for an info_struct for the application. */ +PNG_FUNCTION(png_infop,PNGAPI +png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED) +{ + png_inforp info_ptr; + + png_debug(1, "in png_create_info_struct"); + + if (png_ptr == NULL) + return NULL; + + /* Use the internal API that does not (or at least should not) error out, so + * that this call always returns ok. The application typically sets up the + * error handling *after* creating the info_struct because this is the way it + * has always been done in 'example.c'. + */ + info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr, + (sizeof *info_ptr))); + + if (info_ptr != NULL) + memset(info_ptr, 0, (sizeof *info_ptr)); + + return info_ptr; +} + +/* This function frees the memory associated with a single info struct. + * Normally, one would use either png_destroy_read_struct() or + * png_destroy_write_struct() to free an info struct, but this may be + * useful for some applications. From libpng 1.6.0 this function is also used + * internally to implement the png_info release part of the 'struct' destroy + * APIs. This ensures that all possible approaches free the same data (all of + * it). + */ +void PNGAPI +png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr) +{ + png_inforp info_ptr = NULL; + + png_debug(1, "in png_destroy_info_struct"); + + if (png_ptr == NULL) + return; + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (info_ptr != NULL) + { + /* Do this first in case of an error below; if the app implements its own + * memory management this can lead to png_free calling png_error, which + * will abort this routine and return control to the app error handler. + * An infinite loop may result if it then tries to free the same info + * ptr. + */ + *info_ptr_ptr = NULL; + + png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1); + memset(info_ptr, 0, (sizeof *info_ptr)); + png_free(png_ptr, info_ptr); + } +} + +/* Initialize the info structure. This is now an internal function (0.89) + * and applications using it are urged to use png_create_info_struct() + * instead. Use deprecated in 1.6.0, internal use removed (used internally it + * is just a memset). + * + * NOTE: it is almost inconceivable that this API is used because it bypasses + * the user-memory mechanism and the user error handling/warning mechanisms in + * those cases where it does anything other than a memset. + */ +PNG_FUNCTION(void,PNGAPI +png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size), + PNG_DEPRECATED) +{ + png_inforp info_ptr = *ptr_ptr; + + png_debug(1, "in png_info_init_3"); + + if (info_ptr == NULL) + return; + + if ((sizeof (png_info)) > png_info_struct_size) + { + *ptr_ptr = NULL; + /* The following line is why this API should not be used: */ + free(info_ptr); + info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL, + (sizeof *info_ptr))); + if (info_ptr == NULL) + return; + *ptr_ptr = info_ptr; + } + + /* Set everything to 0 */ + memset(info_ptr, 0, (sizeof *info_ptr)); +} + +/* The following API is not called internally */ +void PNGAPI +png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr, + int freer, png_uint_32 mask) +{ + png_debug(1, "in png_data_freer"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (freer == PNG_DESTROY_WILL_FREE_DATA) + info_ptr->free_me |= mask; + + else if (freer == PNG_USER_WILL_FREE_DATA) + info_ptr->free_me &= ~mask; + + else + png_error(png_ptr, "Unknown freer parameter in png_data_freer"); +} + +void PNGAPI +png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask, + int num) +{ + png_debug(1, "in png_free_data"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + +#ifdef PNG_TEXT_SUPPORTED + /* Free text item num or (if num == -1) all text items */ + if (info_ptr->text != 0 && + ((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0) + { + if (num != -1) + { + png_free(png_ptr, info_ptr->text[num].key); + info_ptr->text[num].key = NULL; + } + + else + { + int i; + + for (i = 0; i < info_ptr->num_text; i++) + png_free(png_ptr, info_ptr->text[i].key); + + png_free(png_ptr, info_ptr->text); + info_ptr->text = NULL; + info_ptr->num_text = 0; + } + } +#endif + +#ifdef PNG_tRNS_SUPPORTED + /* Free any tRNS entry */ + if (((mask & PNG_FREE_TRNS) & info_ptr->free_me) != 0) + { + info_ptr->valid &= ~PNG_INFO_tRNS; + png_free(png_ptr, info_ptr->trans_alpha); + info_ptr->trans_alpha = NULL; + info_ptr->num_trans = 0; + } +#endif + +#ifdef PNG_sCAL_SUPPORTED + /* Free any sCAL entry */ + if (((mask & PNG_FREE_SCAL) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->scal_s_width); + png_free(png_ptr, info_ptr->scal_s_height); + info_ptr->scal_s_width = NULL; + info_ptr->scal_s_height = NULL; + info_ptr->valid &= ~PNG_INFO_sCAL; + } +#endif + +#ifdef PNG_pCAL_SUPPORTED + /* Free any pCAL entry */ + if (((mask & PNG_FREE_PCAL) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->pcal_purpose); + png_free(png_ptr, info_ptr->pcal_units); + info_ptr->pcal_purpose = NULL; + info_ptr->pcal_units = NULL; + + if (info_ptr->pcal_params != NULL) + { + int i; + + for (i = 0; i < info_ptr->pcal_nparams; i++) + png_free(png_ptr, info_ptr->pcal_params[i]); + + png_free(png_ptr, info_ptr->pcal_params); + info_ptr->pcal_params = NULL; + } + info_ptr->valid &= ~PNG_INFO_pCAL; + } +#endif + +#ifdef PNG_iCCP_SUPPORTED + /* Free any profile entry */ + if (((mask & PNG_FREE_ICCP) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->iccp_name); + png_free(png_ptr, info_ptr->iccp_profile); + info_ptr->iccp_name = NULL; + info_ptr->iccp_profile = NULL; + info_ptr->valid &= ~PNG_INFO_iCCP; + } +#endif + +#ifdef PNG_sPLT_SUPPORTED + /* Free a given sPLT entry, or (if num == -1) all sPLT entries */ + if (info_ptr->splt_palettes != 0 && + ((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0) + { + if (num != -1) + { + png_free(png_ptr, info_ptr->splt_palettes[num].name); + png_free(png_ptr, info_ptr->splt_palettes[num].entries); + info_ptr->splt_palettes[num].name = NULL; + info_ptr->splt_palettes[num].entries = NULL; + } + + else + { + int i; + + for (i = 0; i < info_ptr->splt_palettes_num; i++) + { + png_free(png_ptr, info_ptr->splt_palettes[i].name); + png_free(png_ptr, info_ptr->splt_palettes[i].entries); + } + + png_free(png_ptr, info_ptr->splt_palettes); + info_ptr->splt_palettes = NULL; + info_ptr->splt_palettes_num = 0; + info_ptr->valid &= ~PNG_INFO_sPLT; + } + } +#endif + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + if (info_ptr->unknown_chunks != 0 && + ((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0) + { + if (num != -1) + { + png_free(png_ptr, info_ptr->unknown_chunks[num].data); + info_ptr->unknown_chunks[num].data = NULL; + } + + else + { + int i; + + for (i = 0; i < info_ptr->unknown_chunks_num; i++) + png_free(png_ptr, info_ptr->unknown_chunks[i].data); + + png_free(png_ptr, info_ptr->unknown_chunks); + info_ptr->unknown_chunks = NULL; + info_ptr->unknown_chunks_num = 0; + } + } +#endif + +#ifdef PNG_hIST_SUPPORTED + /* Free any hIST entry */ + if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->hist); + info_ptr->hist = NULL; + info_ptr->valid &= ~PNG_INFO_hIST; + } +#endif + + /* Free any PLTE entry that was internally allocated */ + if (((mask & PNG_FREE_PLTE) & info_ptr->free_me) != 0) + { + png_free(png_ptr, info_ptr->palette); + info_ptr->palette = NULL; + info_ptr->valid &= ~PNG_INFO_PLTE; + info_ptr->num_palette = 0; + } + +#ifdef PNG_INFO_IMAGE_SUPPORTED + /* Free any image bits attached to the info structure */ + if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0) + { + if (info_ptr->row_pointers != 0) + { + png_uint_32 row; + for (row = 0; row < info_ptr->height; row++) + png_free(png_ptr, info_ptr->row_pointers[row]); + + png_free(png_ptr, info_ptr->row_pointers); + info_ptr->row_pointers = NULL; + } + info_ptr->valid &= ~PNG_INFO_IDAT; + } +#endif + + if (num != -1) + mask &= ~PNG_FREE_MUL; + + info_ptr->free_me &= ~mask; +} +#endif /* READ || WRITE */ + +/* This function returns a pointer to the io_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy() or png_read_destroy() are called. + */ +png_voidp PNGAPI +png_get_io_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return (png_ptr->io_ptr); +} + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +# ifdef PNG_STDIO_SUPPORTED +/* Initialize the default input/output functions for the PNG file. If you + * use your own read or write routines, you can call either png_set_read_fn() + * or png_set_write_fn() instead of png_init_io(). If you have defined + * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a + * function of your own because "FILE *" isn't necessarily available. + */ +void PNGAPI +png_init_io(png_structrp png_ptr, png_FILE_p fp) +{ + png_debug(1, "in png_init_io"); + + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = (png_voidp)fp; +} +# endif + +# ifdef PNG_SAVE_INT_32_SUPPORTED +/* PNG signed integers are saved in 32-bit 2's complement format. ANSI C-90 + * defines a cast of a signed integer to an unsigned integer either to preserve + * the value, if it is positive, or to calculate: + * + * (UNSIGNED_MAX+1) + integer + * + * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the + * negative integral value is added the result will be an unsigned value + * correspnding to the 2's complement representation. + */ +void PNGAPI +png_save_int_32(png_bytep buf, png_int_32 i) +{ + png_save_uint_32(buf, i); +} +# endif + +# ifdef PNG_TIME_RFC1123_SUPPORTED +/* Convert the supplied time into an RFC 1123 string suitable for use in + * a "Creation Time" or other text-based time string. + */ +int PNGAPI +png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime) +{ + static PNG_CONST char short_months[12][4] = + {"Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; + + if (out == NULL) + return 0; + + if (ptime->year > 9999 /* RFC1123 limitation */ || + ptime->month == 0 || ptime->month > 12 || + ptime->day == 0 || ptime->day > 31 || + ptime->hour > 23 || ptime->minute > 59 || + ptime->second > 60) + return 0; + + { + size_t pos = 0; + char number_buf[5]; /* enough for a four-digit year */ + +# define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string)) +# define APPEND_NUMBER(format, value)\ + APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value))) +# define APPEND(ch) if (pos < 28) out[pos++] = (ch) + + APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day); + APPEND(' '); + APPEND_STRING(short_months[(ptime->month - 1)]); + APPEND(' '); + APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year); + APPEND(' '); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour); + APPEND(':'); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute); + APPEND(':'); + APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second); + APPEND_STRING(" +0000"); /* This reliably terminates the buffer */ + PNG_UNUSED (pos) + +# undef APPEND +# undef APPEND_NUMBER +# undef APPEND_STRING + } + + return 1; +} + +# if PNG_LIBPNG_VER < 10700 +/* To do: remove the following from libpng-1.7 */ +/* Original API that uses a private buffer in png_struct. + * Deprecated because it causes png_struct to carry a spurious temporary + * buffer (png_struct::time_buffer), better to have the caller pass this in. + */ +png_const_charp PNGAPI +png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime) +{ + if (png_ptr != NULL) + { + /* The only failure above if png_ptr != NULL is from an invalid ptime */ + if (png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime) == 0) + png_warning(png_ptr, "Ignoring invalid time value"); + + else + return png_ptr->time_buffer; + } + + return NULL; +} +# endif /* LIBPNG_VER < 10700 */ +# endif /* TIME_RFC1123 */ + +#endif /* READ || WRITE */ + +png_const_charp PNGAPI +png_get_copyright(png_const_structrp png_ptr) +{ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ +#ifdef PNG_STRING_COPYRIGHT + return PNG_STRING_COPYRIGHT +#else +# ifdef __STDC__ + return PNG_STRING_NEWLINE \ + "libpng version 1.6.23 - June 9, 2016" PNG_STRING_NEWLINE \ + "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \ + PNG_STRING_NEWLINE \ + "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \ + "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \ + PNG_STRING_NEWLINE; +# else + return "libpng version 1.6.23 - June 9, 2016\ + Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\ + Copyright (c) 1996-1997 Andreas Dilger\ + Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc."; +# endif +#endif +} + +/* The following return the library version as a short string in the + * format 1.0.0 through 99.99.99zz. To get the version of *.h files + * used with your application, print out PNG_LIBPNG_VER_STRING, which + * is defined in png.h. + * Note: now there is no difference between png_get_libpng_ver() and + * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard, + * it is guaranteed that png.c uses the correct version of png.h. + */ +png_const_charp PNGAPI +png_get_libpng_ver(png_const_structrp png_ptr) +{ + /* Version of *.c files used when building libpng */ + return png_get_header_ver(png_ptr); +} + +png_const_charp PNGAPI +png_get_header_ver(png_const_structrp png_ptr) +{ + /* Version of *.h files used when building libpng */ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ + return PNG_LIBPNG_VER_STRING; +} + +png_const_charp PNGAPI +png_get_header_version(png_const_structrp png_ptr) +{ + /* Returns longer string containing both version and date */ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ +#ifdef __STDC__ + return PNG_HEADER_VERSION_STRING +# ifndef PNG_READ_SUPPORTED + " (NO READ SUPPORT)" +# endif + PNG_STRING_NEWLINE; +#else + return PNG_HEADER_VERSION_STRING; +#endif +} + +#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +/* NOTE: this routine is not used internally! */ +/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth + * large of png_color. This lets grayscale images be treated as + * paletted. Most useful for gamma correction and simplification + * of code. This API is not used internally. + */ +void PNGAPI +png_build_grayscale_palette(int bit_depth, png_colorp palette) +{ + int num_palette; + int color_inc; + int i; + int v; + + png_debug(1, "in png_do_build_grayscale_palette"); + + if (palette == NULL) + return; + + switch (bit_depth) + { + case 1: + num_palette = 2; + color_inc = 0xff; + break; + + case 2: + num_palette = 4; + color_inc = 0x55; + break; + + case 4: + num_palette = 16; + color_inc = 0x11; + break; + + case 8: + num_palette = 256; + color_inc = 1; + break; + + default: + num_palette = 0; + color_inc = 0; + break; + } + + for (i = 0, v = 0; i < num_palette; i++, v += color_inc) + { + palette[i].red = (png_byte)(v & 0xff); + palette[i].green = (png_byte)(v & 0xff); + palette[i].blue = (png_byte)(v & 0xff); + } +} +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED +int PNGAPI +png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name) +{ + /* Check chunk_name and return "keep" value if it's on the list, else 0 */ + png_const_bytep p, p_end; + + if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list == 0) + return PNG_HANDLE_CHUNK_AS_DEFAULT; + + p_end = png_ptr->chunk_list; + p = p_end + png_ptr->num_chunk_list*5; /* beyond end */ + + /* The code is the fifth byte after each four byte string. Historically this + * code was always searched from the end of the list, this is no longer + * necessary because the 'set' routine handles duplicate entries correcty. + */ + do /* num_chunk_list > 0, so at least one */ + { + p -= 5; + + if (memcmp(chunk_name, p, 4) == 0) + return p[4]; + } + while (p > p_end); + + /* This means that known chunks should be processed and unknown chunks should + * be handled according to the value of png_ptr->unknown_default; this can be + * confusing because, as a result, there are two levels of defaulting for + * unknown chunks. + */ + return PNG_HANDLE_CHUNK_AS_DEFAULT; +} + +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\ + defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) +int /* PRIVATE */ +png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name) +{ + png_byte chunk_string[5]; + + PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name); + return png_handle_as_unknown(png_ptr, chunk_string); +} +#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */ +#endif /* SET_UNKNOWN_CHUNKS */ + +#ifdef PNG_READ_SUPPORTED +/* This function, added to libpng-1.0.6g, is untested. */ +int PNGAPI +png_reset_zstream(png_structrp png_ptr) +{ + if (png_ptr == NULL) + return Z_STREAM_ERROR; + + /* WARNING: this resets the window bits to the maximum! */ + return (inflateReset(&png_ptr->zstream)); +} +#endif /* READ */ + +/* This function was added to libpng-1.0.7 */ +png_uint_32 PNGAPI +png_access_version_number(void) +{ + /* Version of *.c files used when building libpng */ + return((png_uint_32)PNG_LIBPNG_VER); +} + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +/* Ensure that png_ptr->zstream.msg holds some appropriate error message string. + * If it doesn't 'ret' is used to set it to something appropriate, even in cases + * like Z_OK or Z_STREAM_END where the error code is apparently a success code. + */ +void /* PRIVATE */ +png_zstream_error(png_structrp png_ptr, int ret) +{ + /* Translate 'ret' into an appropriate error string, priority is given to the + * one in zstream if set. This always returns a string, even in cases like + * Z_OK or Z_STREAM_END where the error code is a success code. + */ + if (png_ptr->zstream.msg == NULL) switch (ret) + { + default: + case Z_OK: + png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return code"); + break; + + case Z_STREAM_END: + /* Normal exit */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected end of LZ stream"); + break; + + case Z_NEED_DICT: + /* This means the deflate stream did not have a dictionary; this + * indicates a bogus PNG. + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("missing LZ dictionary"); + break; + + case Z_ERRNO: + /* gz APIs only: should not happen */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("zlib IO error"); + break; + + case Z_STREAM_ERROR: + /* internal libpng error */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("bad parameters to zlib"); + break; + + case Z_DATA_ERROR: + png_ptr->zstream.msg = PNGZ_MSG_CAST("damaged LZ stream"); + break; + + case Z_MEM_ERROR: + png_ptr->zstream.msg = PNGZ_MSG_CAST("insufficient memory"); + break; + + case Z_BUF_ERROR: + /* End of input or output; not a problem if the caller is doing + * incremental read or write. + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("truncated"); + break; + + case Z_VERSION_ERROR: + png_ptr->zstream.msg = PNGZ_MSG_CAST("unsupported zlib version"); + break; + + case PNG_UNEXPECTED_ZLIB_RETURN: + /* Compile errors here mean that zlib now uses the value co-opted in + * pngpriv.h for PNG_UNEXPECTED_ZLIB_RETURN; update the switch above + * and change pngpriv.h. Note that this message is "... return", + * whereas the default/Z_OK one is "... return code". + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return"); + break; + } +} + +/* png_convert_size: a PNGAPI but no longer in png.h, so deleted + * at libpng 1.5.5! + */ + +/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */ +#ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */ +static int +png_colorspace_check_gamma(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_fixed_point gAMA, int from) + /* This is called to check a new gamma value against an existing one. The + * routine returns false if the new gamma value should not be written. + * + * 'from' says where the new gamma value comes from: + * + * 0: the new gamma value is the libpng estimate for an ICC profile + * 1: the new gamma value comes from a gAMA chunk + * 2: the new gamma value comes from an sRGB chunk + */ +{ + png_fixed_point gtest; + + if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && + (png_muldiv(>est, colorspace->gamma, PNG_FP_1, gAMA) == 0 || + png_gamma_significant(gtest) != 0)) + { + /* Either this is an sRGB image, in which case the calculated gamma + * approximation should match, or this is an image with a profile and the + * value libpng calculates for the gamma of the profile does not match the + * value recorded in the file. The former, sRGB, case is an error, the + * latter is just a warning. + */ + if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2) + { + png_chunk_report(png_ptr, "gamma value does not match sRGB", + PNG_CHUNK_ERROR); + /* Do not overwrite an sRGB value */ + return from == 2; + } + + else /* sRGB tag not involved */ + { + png_chunk_report(png_ptr, "gamma value does not match libpng estimate", + PNG_CHUNK_WARNING); + return from == 1; + } + } + + return 1; +} + +void /* PRIVATE */ +png_colorspace_set_gamma(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_fixed_point gAMA) +{ + /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't + * occur. Since the fixed point representation is asymetrical it is + * possible for 1/gamma to overflow the limit of 21474 and this means the + * gamma value must be at least 5/100000 and hence at most 20000.0. For + * safety the limits here are a little narrower. The values are 0.00016 to + * 6250.0, which are truly ridiculous gamma values (and will produce + * displays that are all black or all white.) + * + * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk + * handling code, which only required the value to be >0. + */ + png_const_charp errmsg; + + if (gAMA < 16 || gAMA > 625000000) + errmsg = "gamma value out of range"; + +# ifdef PNG_READ_gAMA_SUPPORTED + /* Allow the application to set the gamma value more than once */ + else if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + (colorspace->flags & PNG_COLORSPACE_FROM_gAMA) != 0) + errmsg = "duplicate"; +# endif + + /* Do nothing if the colorspace is already invalid */ + else if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return; + + else + { + if (png_colorspace_check_gamma(png_ptr, colorspace, gAMA, + 1/*from gAMA*/) != 0) + { + /* Store this gamma value. */ + colorspace->gamma = gAMA; + colorspace->flags |= + (PNG_COLORSPACE_HAVE_GAMMA | PNG_COLORSPACE_FROM_gAMA); + } + + /* At present if the check_gamma test fails the gamma of the colorspace is + * not updated however the colorspace is not invalidated. This + * corresponds to the case where the existing gamma comes from an sRGB + * chunk or profile. An error message has already been output. + */ + return; + } + + /* Error exit - errmsg has been set. */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_chunk_report(png_ptr, errmsg, PNG_CHUNK_WRITE_ERROR); +} + +void /* PRIVATE */ +png_colorspace_sync_info(png_const_structrp png_ptr, png_inforp info_ptr) +{ + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + { + /* Everything is invalid */ + info_ptr->valid &= ~(PNG_INFO_gAMA|PNG_INFO_cHRM|PNG_INFO_sRGB| + PNG_INFO_iCCP); + +# ifdef PNG_COLORSPACE_SUPPORTED + /* Clean up the iCCP profile now if it won't be used. */ + png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, -1/*not used*/); +# else + PNG_UNUSED(png_ptr) +# endif + } + + else + { +# ifdef PNG_COLORSPACE_SUPPORTED + /* Leave the INFO_iCCP flag set if the pngset.c code has already set + * it; this allows a PNG to contain a profile which matches sRGB and + * yet still have that profile retrievable by the application. + */ + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_MATCHES_sRGB) != 0) + info_ptr->valid |= PNG_INFO_sRGB; + + else + info_ptr->valid &= ~PNG_INFO_sRGB; + + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + info_ptr->valid |= PNG_INFO_cHRM; + + else + info_ptr->valid &= ~PNG_INFO_cHRM; +# endif + + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0) + info_ptr->valid |= PNG_INFO_gAMA; + + else + info_ptr->valid &= ~PNG_INFO_gAMA; + } +} + +#ifdef PNG_READ_SUPPORTED +void /* PRIVATE */ +png_colorspace_sync(png_const_structrp png_ptr, png_inforp info_ptr) +{ + if (info_ptr == NULL) /* reduce code size; check here not in the caller */ + return; + + info_ptr->colorspace = png_ptr->colorspace; + png_colorspace_sync_info(png_ptr, info_ptr); +} +#endif +#endif /* GAMMA */ + +#ifdef PNG_COLORSPACE_SUPPORTED +/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for + * cHRM, as opposed to using chromaticities. These internal APIs return + * non-zero on a parameter error. The X, Y and Z values are required to be + * positive and less than 1.0. + */ +static int +png_xy_from_XYZ(png_xy *xy, const png_XYZ *XYZ) +{ + png_int_32 d, dwhite, whiteX, whiteY; + + d = XYZ->red_X + XYZ->red_Y + XYZ->red_Z; + if (png_muldiv(&xy->redx, XYZ->red_X, PNG_FP_1, d) == 0) + return 1; + if (png_muldiv(&xy->redy, XYZ->red_Y, PNG_FP_1, d) == 0) + return 1; + dwhite = d; + whiteX = XYZ->red_X; + whiteY = XYZ->red_Y; + + d = XYZ->green_X + XYZ->green_Y + XYZ->green_Z; + if (png_muldiv(&xy->greenx, XYZ->green_X, PNG_FP_1, d) == 0) + return 1; + if (png_muldiv(&xy->greeny, XYZ->green_Y, PNG_FP_1, d) == 0) + return 1; + dwhite += d; + whiteX += XYZ->green_X; + whiteY += XYZ->green_Y; + + d = XYZ->blue_X + XYZ->blue_Y + XYZ->blue_Z; + if (png_muldiv(&xy->bluex, XYZ->blue_X, PNG_FP_1, d) == 0) + return 1; + if (png_muldiv(&xy->bluey, XYZ->blue_Y, PNG_FP_1, d) == 0) + return 1; + dwhite += d; + whiteX += XYZ->blue_X; + whiteY += XYZ->blue_Y; + + /* The reference white is simply the sum of the end-point (X,Y,Z) vectors, + * thus: + */ + if (png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite) == 0) + return 1; + if (png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite) == 0) + return 1; + + return 0; +} + +static int +png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy) +{ + png_fixed_point red_inverse, green_inverse, blue_scale; + png_fixed_point left, right, denominator; + + /* Check xy and, implicitly, z. Note that wide gamut color spaces typically + * have end points with 0 tristimulus values (these are impossible end + * points, but they are used to cover the possible colors). We check + * xy->whitey against 5, not 0, to avoid a possible integer overflow. + */ + if (xy->redx < 0 || xy->redx > PNG_FP_1) return 1; + if (xy->redy < 0 || xy->redy > PNG_FP_1-xy->redx) return 1; + if (xy->greenx < 0 || xy->greenx > PNG_FP_1) return 1; + if (xy->greeny < 0 || xy->greeny > PNG_FP_1-xy->greenx) return 1; + if (xy->bluex < 0 || xy->bluex > PNG_FP_1) return 1; + if (xy->bluey < 0 || xy->bluey > PNG_FP_1-xy->bluex) return 1; + if (xy->whitex < 0 || xy->whitex > PNG_FP_1) return 1; + if (xy->whitey < 5 || xy->whitey > PNG_FP_1-xy->whitex) return 1; + + /* The reverse calculation is more difficult because the original tristimulus + * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8 + * derived values were recorded in the cHRM chunk; + * (red,green,blue,white)x(x,y). This loses one degree of freedom and + * therefore an arbitrary ninth value has to be introduced to undo the + * original transformations. + * + * Think of the original end-points as points in (X,Y,Z) space. The + * chromaticity values (c) have the property: + * + * C + * c = --------- + * X + Y + Z + * + * For each c (x,y,z) from the corresponding original C (X,Y,Z). Thus the + * three chromaticity values (x,y,z) for each end-point obey the + * relationship: + * + * x + y + z = 1 + * + * This describes the plane in (X,Y,Z) space that intersects each axis at the + * value 1.0; call this the chromaticity plane. Thus the chromaticity + * calculation has scaled each end-point so that it is on the x+y+z=1 plane + * and chromaticity is the intersection of the vector from the origin to the + * (X,Y,Z) value with the chromaticity plane. + * + * To fully invert the chromaticity calculation we would need the three + * end-point scale factors, (red-scale, green-scale, blue-scale), but these + * were not recorded. Instead we calculated the reference white (X,Y,Z) and + * recorded the chromaticity of this. The reference white (X,Y,Z) would have + * given all three of the scale factors since: + * + * color-C = color-c * color-scale + * white-C = red-C + green-C + blue-C + * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale + * + * But cHRM records only white-x and white-y, so we have lost the white scale + * factor: + * + * white-C = white-c*white-scale + * + * To handle this the inverse transformation makes an arbitrary assumption + * about white-scale: + * + * Assume: white-Y = 1.0 + * Hence: white-scale = 1/white-y + * Or: red-Y + green-Y + blue-Y = 1.0 + * + * Notice the last statement of the assumption gives an equation in three of + * the nine values we want to calculate. 8 more equations come from the + * above routine as summarised at the top above (the chromaticity + * calculation): + * + * Given: color-x = color-X / (color-X + color-Y + color-Z) + * Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0 + * + * This is 9 simultaneous equations in the 9 variables "color-C" and can be + * solved by Cramer's rule. Cramer's rule requires calculating 10 9x9 matrix + * determinants, however this is not as bad as it seems because only 28 of + * the total of 90 terms in the various matrices are non-zero. Nevertheless + * Cramer's rule is notoriously numerically unstable because the determinant + * calculation involves the difference of large, but similar, numbers. It is + * difficult to be sure that the calculation is stable for real world values + * and it is certain that it becomes unstable where the end points are close + * together. + * + * So this code uses the perhaps slightly less optimal but more + * understandable and totally obvious approach of calculating color-scale. + * + * This algorithm depends on the precision in white-scale and that is + * (1/white-y), so we can immediately see that as white-y approaches 0 the + * accuracy inherent in the cHRM chunk drops off substantially. + * + * libpng arithmetic: a simple inversion of the above equations + * ------------------------------------------------------------ + * + * white_scale = 1/white-y + * white-X = white-x * white-scale + * white-Y = 1.0 + * white-Z = (1 - white-x - white-y) * white_scale + * + * white-C = red-C + green-C + blue-C + * = red-c*red-scale + green-c*green-scale + blue-c*blue-scale + * + * This gives us three equations in (red-scale,green-scale,blue-scale) where + * all the coefficients are now known: + * + * red-x*red-scale + green-x*green-scale + blue-x*blue-scale + * = white-x/white-y + * red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1 + * red-z*red-scale + green-z*green-scale + blue-z*blue-scale + * = (1 - white-x - white-y)/white-y + * + * In the last equation color-z is (1 - color-x - color-y) so we can add all + * three equations together to get an alternative third: + * + * red-scale + green-scale + blue-scale = 1/white-y = white-scale + * + * So now we have a Cramer's rule solution where the determinants are just + * 3x3 - far more tractible. Unfortunately 3x3 determinants still involve + * multiplication of three coefficients so we can't guarantee to avoid + * overflow in the libpng fixed point representation. Using Cramer's rule in + * floating point is probably a good choice here, but it's not an option for + * fixed point. Instead proceed to simplify the first two equations by + * eliminating what is likely to be the largest value, blue-scale: + * + * blue-scale = white-scale - red-scale - green-scale + * + * Hence: + * + * (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale = + * (white-x - blue-x)*white-scale + * + * (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale = + * 1 - blue-y*white-scale + * + * And now we can trivially solve for (red-scale,green-scale): + * + * green-scale = + * (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale + * ----------------------------------------------------------- + * green-x - blue-x + * + * red-scale = + * 1 - blue-y*white-scale - (green-y - blue-y) * green-scale + * --------------------------------------------------------- + * red-y - blue-y + * + * Hence: + * + * red-scale = + * ( (green-x - blue-x) * (white-y - blue-y) - + * (green-y - blue-y) * (white-x - blue-x) ) / white-y + * ------------------------------------------------------------------------- + * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) + * + * green-scale = + * ( (red-y - blue-y) * (white-x - blue-x) - + * (red-x - blue-x) * (white-y - blue-y) ) / white-y + * ------------------------------------------------------------------------- + * (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x) + * + * Accuracy: + * The input values have 5 decimal digits of accuracy. The values are all in + * the range 0 < value < 1, so simple products are in the same range but may + * need up to 10 decimal digits to preserve the original precision and avoid + * underflow. Because we are using a 32-bit signed representation we cannot + * match this; the best is a little over 9 decimal digits, less than 10. + * + * The approach used here is to preserve the maximum precision within the + * signed representation. Because the red-scale calculation above uses the + * difference between two products of values that must be in the range -1..+1 + * it is sufficient to divide the product by 7; ceil(100,000/32767*2). The + * factor is irrelevant in the calculation because it is applied to both + * numerator and denominator. + * + * Note that the values of the differences of the products of the + * chromaticities in the above equations tend to be small, for example for + * the sRGB chromaticities they are: + * + * red numerator: -0.04751 + * green numerator: -0.08788 + * denominator: -0.2241 (without white-y multiplication) + * + * The resultant Y coefficients from the chromaticities of some widely used + * color space definitions are (to 15 decimal places): + * + * sRGB + * 0.212639005871510 0.715168678767756 0.072192315360734 + * Kodak ProPhoto + * 0.288071128229293 0.711843217810102 0.000085653960605 + * Adobe RGB + * 0.297344975250536 0.627363566255466 0.075291458493998 + * Adobe Wide Gamut RGB + * 0.258728243040113 0.724682314948566 0.016589442011321 + */ + /* By the argument, above overflow should be impossible here. The return + * value of 2 indicates an internal error to the caller. + */ + if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 7) == 0) + return 2; + if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 7) == 0) + return 2; + denominator = left - right; + + /* Now find the red numerator. */ + if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 7) == 0) + return 2; + if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 7) == 0) + return 2; + + /* Overflow is possible here and it indicates an extreme set of PNG cHRM + * chunk values. This calculation actually returns the reciprocal of the + * scale value because this allows us to delay the multiplication of white-y + * into the denominator, which tends to produce a small number. + */ + if (png_muldiv(&red_inverse, xy->whitey, denominator, left-right) == 0 || + red_inverse <= xy->whitey /* r+g+b scales = white scale */) + return 1; + + /* Similarly for green_inverse: */ + if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 7) == 0) + return 2; + if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 7) == 0) + return 2; + if (png_muldiv(&green_inverse, xy->whitey, denominator, left-right) == 0 || + green_inverse <= xy->whitey) + return 1; + + /* And the blue scale, the checks above guarantee this can't overflow but it + * can still produce 0 for extreme cHRM values. + */ + blue_scale = png_reciprocal(xy->whitey) - png_reciprocal(red_inverse) - + png_reciprocal(green_inverse); + if (blue_scale <= 0) + return 1; + + + /* And fill in the png_XYZ: */ + if (png_muldiv(&XYZ->red_X, xy->redx, PNG_FP_1, red_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->red_Y, xy->redy, PNG_FP_1, red_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->red_Z, PNG_FP_1 - xy->redx - xy->redy, PNG_FP_1, + red_inverse) == 0) + return 1; + + if (png_muldiv(&XYZ->green_X, xy->greenx, PNG_FP_1, green_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->green_Y, xy->greeny, PNG_FP_1, green_inverse) == 0) + return 1; + if (png_muldiv(&XYZ->green_Z, PNG_FP_1 - xy->greenx - xy->greeny, PNG_FP_1, + green_inverse) == 0) + return 1; + + if (png_muldiv(&XYZ->blue_X, xy->bluex, blue_scale, PNG_FP_1) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Y, xy->bluey, blue_scale, PNG_FP_1) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Z, PNG_FP_1 - xy->bluex - xy->bluey, blue_scale, + PNG_FP_1) == 0) + return 1; + + return 0; /*success*/ +} + +static int +png_XYZ_normalize(png_XYZ *XYZ) +{ + png_int_32 Y; + + if (XYZ->red_Y < 0 || XYZ->green_Y < 0 || XYZ->blue_Y < 0 || + XYZ->red_X < 0 || XYZ->green_X < 0 || XYZ->blue_X < 0 || + XYZ->red_Z < 0 || XYZ->green_Z < 0 || XYZ->blue_Z < 0) + return 1; + + /* Normalize by scaling so the sum of the end-point Y values is PNG_FP_1. + * IMPLEMENTATION NOTE: ANSI requires signed overflow not to occur, therefore + * relying on addition of two positive values producing a negative one is not + * safe. + */ + Y = XYZ->red_Y; + if (0x7fffffff - Y < XYZ->green_X) + return 1; + Y += XYZ->green_Y; + if (0x7fffffff - Y < XYZ->blue_X) + return 1; + Y += XYZ->blue_Y; + + if (Y != PNG_FP_1) + { + if (png_muldiv(&XYZ->red_X, XYZ->red_X, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->red_Y, XYZ->red_Y, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->red_Z, XYZ->red_Z, PNG_FP_1, Y) == 0) + return 1; + + if (png_muldiv(&XYZ->green_X, XYZ->green_X, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->green_Y, XYZ->green_Y, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->green_Z, XYZ->green_Z, PNG_FP_1, Y) == 0) + return 1; + + if (png_muldiv(&XYZ->blue_X, XYZ->blue_X, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Y, XYZ->blue_Y, PNG_FP_1, Y) == 0) + return 1; + if (png_muldiv(&XYZ->blue_Z, XYZ->blue_Z, PNG_FP_1, Y) == 0) + return 1; + } + + return 0; +} + +static int +png_colorspace_endpoints_match(const png_xy *xy1, const png_xy *xy2, int delta) +{ + /* Allow an error of +/-0.01 (absolute value) on each chromaticity */ + if (PNG_OUT_OF_RANGE(xy1->whitex, xy2->whitex,delta) || + PNG_OUT_OF_RANGE(xy1->whitey, xy2->whitey,delta) || + PNG_OUT_OF_RANGE(xy1->redx, xy2->redx, delta) || + PNG_OUT_OF_RANGE(xy1->redy, xy2->redy, delta) || + PNG_OUT_OF_RANGE(xy1->greenx, xy2->greenx,delta) || + PNG_OUT_OF_RANGE(xy1->greeny, xy2->greeny,delta) || + PNG_OUT_OF_RANGE(xy1->bluex, xy2->bluex, delta) || + PNG_OUT_OF_RANGE(xy1->bluey, xy2->bluey, delta)) + return 0; + return 1; +} + +/* Added in libpng-1.6.0, a different check for the validity of a set of cHRM + * chunk chromaticities. Earlier checks used to simply look for the overflow + * condition (where the determinant of the matrix to solve for XYZ ends up zero + * because the chromaticity values are not all distinct.) Despite this it is + * theoretically possible to produce chromaticities that are apparently valid + * but that rapidly degrade to invalid, potentially crashing, sets because of + * arithmetic inaccuracies when calculations are performed on them. The new + * check is to round-trip xy -> XYZ -> xy and then check that the result is + * within a small percentage of the original. + */ +static int +png_colorspace_check_xy(png_XYZ *XYZ, const png_xy *xy) +{ + int result; + png_xy xy_test; + + /* As a side-effect this routine also returns the XYZ endpoints. */ + result = png_XYZ_from_xy(XYZ, xy); + if (result != 0) + return result; + + result = png_xy_from_XYZ(&xy_test, XYZ); + if (result != 0) + return result; + + if (png_colorspace_endpoints_match(xy, &xy_test, + 5/*actually, the math is pretty accurate*/) != 0) + return 0; + + /* Too much slip */ + return 1; +} + +/* This is the check going the other way. The XYZ is modified to normalize it + * (another side-effect) and the xy chromaticities are returned. + */ +static int +png_colorspace_check_XYZ(png_xy *xy, png_XYZ *XYZ) +{ + int result; + png_XYZ XYZtemp; + + result = png_XYZ_normalize(XYZ); + if (result != 0) + return result; + + result = png_xy_from_XYZ(xy, XYZ); + if (result != 0) + return result; + + XYZtemp = *XYZ; + return png_colorspace_check_xy(&XYZtemp, xy); +} + +/* Used to check for an endpoint match against sRGB */ +static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */ +{ + /* color x y */ + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000, + /* white */ 31270, 32900 +}; + +static int +png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr, + png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ, + int preferred) +{ + if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return 0; + + /* The consistency check is performed on the chromaticities; this factors out + * variations because of the normalization (or not) of the end point Y + * values. + */ + if (preferred < 2 && + (colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + /* The end points must be reasonably close to any we already have. The + * following allows an error of up to +/-.001 + */ + if (png_colorspace_endpoints_match(xy, &colorspace->end_points_xy, + 100) == 0) + { + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_benign_error(png_ptr, "inconsistent chromaticities"); + return 0; /* failed */ + } + + /* Only overwrite with preferred values */ + if (preferred == 0) + return 1; /* ok, but no change */ + } + + colorspace->end_points_xy = *xy; + colorspace->end_points_XYZ = *XYZ; + colorspace->flags |= PNG_COLORSPACE_HAVE_ENDPOINTS; + + /* The end points are normally quoted to two decimal digits, so allow +/-0.01 + * on this test. + */ + if (png_colorspace_endpoints_match(xy, &sRGB_xy, 1000) != 0) + colorspace->flags |= PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB; + + else + colorspace->flags &= PNG_COLORSPACE_CANCEL( + PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB); + + return 2; /* ok and changed */ +} + +int /* PRIVATE */ +png_colorspace_set_chromaticities(png_const_structrp png_ptr, + png_colorspacerp colorspace, const png_xy *xy, int preferred) +{ + /* We must check the end points to ensure they are reasonable - in the past + * color management systems have crashed as a result of getting bogus + * colorant values, while this isn't the fault of libpng it is the + * responsibility of libpng because PNG carries the bomb and libpng is in a + * position to protect against it. + */ + png_XYZ XYZ; + + switch (png_colorspace_check_xy(&XYZ, xy)) + { + case 0: /* success */ + return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ, + preferred); + + case 1: + /* We can't invert the chromaticities so we can't produce value XYZ + * values. Likely as not a color management system will fail too. + */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_benign_error(png_ptr, "invalid chromaticities"); + break; + + default: + /* libpng is broken; this should be a warning but if it happens we + * want error reports so for the moment it is an error. + */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_error(png_ptr, "internal error checking chromaticities"); + } + + return 0; /* failed */ +} + +int /* PRIVATE */ +png_colorspace_set_endpoints(png_const_structrp png_ptr, + png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred) +{ + png_XYZ XYZ = *XYZ_in; + png_xy xy; + + switch (png_colorspace_check_XYZ(&xy, &XYZ)) + { + case 0: + return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ, + preferred); + + case 1: + /* End points are invalid. */ + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_benign_error(png_ptr, "invalid end points"); + break; + + default: + colorspace->flags |= PNG_COLORSPACE_INVALID; + png_error(png_ptr, "internal error checking chromaticities"); + } + + return 0; /* failed */ +} + +#if defined(PNG_sRGB_SUPPORTED) || defined(PNG_iCCP_SUPPORTED) +/* Error message generation */ +static char +png_icc_tag_char(png_uint_32 byte) +{ + byte &= 0xff; + if (byte >= 32 && byte <= 126) + return (char)byte; + else + return '?'; +} + +static void +png_icc_tag_name(char *name, png_uint_32 tag) +{ + name[0] = '\''; + name[1] = png_icc_tag_char(tag >> 24); + name[2] = png_icc_tag_char(tag >> 16); + name[3] = png_icc_tag_char(tag >> 8); + name[4] = png_icc_tag_char(tag ); + name[5] = '\''; +} + +static int +is_ICC_signature_char(png_alloc_size_t it) +{ + return it == 32 || (it >= 48 && it <= 57) || (it >= 65 && it <= 90) || + (it >= 97 && it <= 122); +} + +static int +is_ICC_signature(png_alloc_size_t it) +{ + return is_ICC_signature_char(it >> 24) /* checks all the top bits */ && + is_ICC_signature_char((it >> 16) & 0xff) && + is_ICC_signature_char((it >> 8) & 0xff) && + is_ICC_signature_char(it & 0xff); +} + +static int +png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_alloc_size_t value, png_const_charp reason) +{ + size_t pos; + char message[196]; /* see below for calculation */ + + if (colorspace != NULL) + colorspace->flags |= PNG_COLORSPACE_INVALID; + + pos = png_safecat(message, (sizeof message), 0, "profile '"); /* 9 chars */ + pos = png_safecat(message, pos+79, pos, name); /* Truncate to 79 chars */ + pos = png_safecat(message, (sizeof message), pos, "': "); /* +2 = 90 */ + if (is_ICC_signature(value) != 0) + { + /* So 'value' is at most 4 bytes and the following cast is safe */ + png_icc_tag_name(message+pos, (png_uint_32)value); + pos += 6; /* total +8; less than the else clause */ + message[pos++] = ':'; + message[pos++] = ' '; + } +# ifdef PNG_WARNINGS_SUPPORTED + else + { + char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/ + + pos = png_safecat(message, (sizeof message), pos, + png_format_number(number, number+(sizeof number), + PNG_NUMBER_FORMAT_x, value)); + pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/ + } +# endif + /* The 'reason' is an arbitrary message, allow +79 maximum 195 */ + pos = png_safecat(message, (sizeof message), pos, reason); + PNG_UNUSED(pos) + + /* This is recoverable, but make it unconditionally an app_error on write to + * avoid writing invalid ICC profiles into PNG files (i.e., we handle them + * on read, with a warning, but on write unless the app turns off + * application errors the PNG won't be written.) + */ + png_chunk_report(png_ptr, message, + (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR); + + return 0; +} +#endif /* sRGB || iCCP */ + +#ifdef PNG_sRGB_SUPPORTED +int /* PRIVATE */ +png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace, + int intent) +{ + /* sRGB sets known gamma, end points and (from the chunk) intent. */ + /* IMPORTANT: these are not necessarily the values found in an ICC profile + * because ICC profiles store values adapted to a D50 environment; it is + * expected that the ICC profile mediaWhitePointTag will be D50; see the + * checks and code elsewhere to understand this better. + * + * These XYZ values, which are accurate to 5dp, produce rgb to gray + * coefficients of (6968,23435,2366), which are reduced (because they add up + * to 32769 not 32768) to (6968,23434,2366). These are the values that + * libpng has traditionally used (and are the best values given the 15bit + * algorithm used by the rgb to gray code.) + */ + static const png_XYZ sRGB_XYZ = /* D65 XYZ (*not* the D50 adapted values!) */ + { + /* color X Y Z */ + /* red */ 41239, 21264, 1933, + /* green */ 35758, 71517, 11919, + /* blue */ 18048, 7219, 95053 + }; + + /* Do nothing if the colorspace is already invalidated. */ + if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return 0; + + /* Check the intent, then check for existing settings. It is valid for the + * PNG file to have cHRM or gAMA chunks along with sRGB, but the values must + * be consistent with the correct values. If, however, this function is + * called below because an iCCP chunk matches sRGB then it is quite + * conceivable that an older app recorded incorrect gAMA and cHRM because of + * an incorrect calculation based on the values in the profile - this does + * *not* invalidate the profile (though it still produces an error, which can + * be ignored.) + */ + if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST) + return png_icc_profile_error(png_ptr, colorspace, "sRGB", + (unsigned)intent, "invalid sRGB rendering intent"); + + if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 && + colorspace->rendering_intent != intent) + return png_icc_profile_error(png_ptr, colorspace, "sRGB", + (unsigned)intent, "inconsistent rendering intents"); + + if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0) + { + png_benign_error(png_ptr, "duplicate sRGB information ignored"); + return 0; + } + + /* If the standard sRGB cHRM chunk does not match the one from the PNG file + * warn but overwrite the value with the correct one. + */ + if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 && + !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy, + 100)) + png_chunk_report(png_ptr, "cHRM chunk does not match sRGB", + PNG_CHUNK_ERROR); + + /* This check is just done for the error reporting - the routine always + * returns true when the 'from' argument corresponds to sRGB (2). + */ + (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE, + 2/*from sRGB*/); + + /* intent: bugs in GCC force 'int' to be used as the parameter type. */ + colorspace->rendering_intent = (png_uint_16)intent; + colorspace->flags |= PNG_COLORSPACE_HAVE_INTENT; + + /* endpoints */ + colorspace->end_points_xy = sRGB_xy; + colorspace->end_points_XYZ = sRGB_XYZ; + colorspace->flags |= + (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB); + + /* gamma */ + colorspace->gamma = PNG_GAMMA_sRGB_INVERSE; + colorspace->flags |= PNG_COLORSPACE_HAVE_GAMMA; + + /* Finally record that we have an sRGB profile */ + colorspace->flags |= + (PNG_COLORSPACE_MATCHES_sRGB|PNG_COLORSPACE_FROM_sRGB); + + return 1; /* set */ +} +#endif /* sRGB */ + +#ifdef PNG_iCCP_SUPPORTED +/* Encoded value of D50 as an ICC XYZNumber. From the ICC 2010 spec the value + * is XYZ(0.9642,1.0,0.8249), which scales to: + * + * (63189.8112, 65536, 54060.6464) + */ +static const png_byte D50_nCIEXYZ[12] = + { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d }; + +int /* PRIVATE */ +png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length) +{ + if (profile_length < 132) + return png_icc_profile_error(png_ptr, colorspace, name, profile_length, + "too short"); + + return 1; +} + +int /* PRIVATE */ +png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length, + png_const_bytep profile/* first 132 bytes only */, int color_type) +{ + png_uint_32 temp; + + /* Length check; this cannot be ignored in this code because profile_length + * is used later to check the tag table, so even if the profile seems over + * long profile_length from the caller must be correct. The caller can fix + * this up on read or write by just passing in the profile header length. + */ + temp = png_get_uint_32(profile); + if (temp != profile_length) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "length does not match profile"); + + temp = (png_uint_32) (*(profile+8)); + if (temp > 3 && (profile_length & 3)) + return png_icc_profile_error(png_ptr, colorspace, name, profile_length, + "invalid length"); + + temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */ + if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */ + profile_length < 132+12*temp) /* truncated tag table */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "tag count too large"); + + /* The 'intent' must be valid or we can't store it, ICC limits the intent to + * 16 bits. + */ + temp = png_get_uint_32(profile+64); + if (temp >= 0xffff) /* The ICC limit */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid rendering intent"); + + /* This is just a warning because the profile may be valid in future + * versions. + */ + if (temp >= PNG_sRGB_INTENT_LAST) + (void)png_icc_profile_error(png_ptr, NULL, name, temp, + "intent outside defined range"); + + /* At this point the tag table can't be checked because it hasn't necessarily + * been loaded; however, various header fields can be checked. These checks + * are for values permitted by the PNG spec in an ICC profile; the PNG spec + * restricts the profiles that can be passed in an iCCP chunk (they must be + * appropriate to processing PNG data!) + */ + + /* Data checks (could be skipped). These checks must be independent of the + * version number; however, the version number doesn't accomodate changes in + * the header fields (just the known tags and the interpretation of the + * data.) + */ + temp = png_get_uint_32(profile+36); /* signature 'ascp' */ + if (temp != 0x61637370) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid signature"); + + /* Currently the PCS illuminant/adopted white point (the computational + * white point) are required to be D50, + * however the profile contains a record of the illuminant so perhaps ICC + * expects to be able to change this in the future (despite the rationale in + * the introduction for using a fixed PCS adopted white.) Consequently the + * following is just a warning. + */ + if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0) + (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/, + "PCS illuminant is not D50"); + + /* The PNG spec requires this: + * "If the iCCP chunk is present, the image samples conform to the colour + * space represented by the embedded ICC profile as defined by the + * International Color Consortium [ICC]. The colour space of the ICC profile + * shall be an RGB colour space for colour images (PNG colour types 2, 3, and + * 6), or a greyscale colour space for greyscale images (PNG colour types 0 + * and 4)." + * + * This checking code ensures the embedded profile (on either read or write) + * conforms to the specification requirements. Notice that an ICC 'gray' + * color-space profile contains the information to transform the monochrome + * data to XYZ or L*a*b (according to which PCS the profile uses) and this + * should be used in preference to the standard libpng K channel replication + * into R, G and B channels. + * + * Previously it was suggested that an RGB profile on grayscale data could be + * handled. However it it is clear that using an RGB profile in this context + * must be an error - there is no specification of what it means. Thus it is + * almost certainly more correct to ignore the profile. + */ + temp = png_get_uint_32(profile+16); /* data colour space field */ + switch (temp) + { + case 0x52474220: /* 'RGB ' */ + if ((color_type & PNG_COLOR_MASK_COLOR) == 0) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "RGB color space not permitted on grayscale PNG"); + break; + + case 0x47524159: /* 'GRAY' */ + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "Gray color space not permitted on RGB PNG"); + break; + + default: + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid ICC profile color space"); + } + + /* It is up to the application to check that the profile class matches the + * application requirements; the spec provides no guidance, but it's pretty + * weird if the profile is not scanner ('scnr'), monitor ('mntr'), printer + * ('prtr') or 'spac' (for generic color spaces). Issue a warning in these + * cases. Issue an error for device link or abstract profiles - these don't + * contain the records necessary to transform the color-space to anything + * other than the target device (and not even that for an abstract profile). + * Profiles of these classes may not be embedded in images. + */ + temp = png_get_uint_32(profile+12); /* profile/device class */ + switch (temp) + { + case 0x73636e72: /* 'scnr' */ + case 0x6d6e7472: /* 'mntr' */ + case 0x70727472: /* 'prtr' */ + case 0x73706163: /* 'spac' */ + /* All supported */ + break; + + case 0x61627374: /* 'abst' */ + /* May not be embedded in an image */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "invalid embedded Abstract ICC profile"); + + case 0x6c696e6b: /* 'link' */ + /* DeviceLink profiles cannot be interpreted in a non-device specific + * fashion, if an app uses the AToB0Tag in the profile the results are + * undefined unless the result is sent to the intended device, + * therefore a DeviceLink profile should not be found embedded in a + * PNG. + */ + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "unexpected DeviceLink ICC profile class"); + + case 0x6e6d636c: /* 'nmcl' */ + /* A NamedColor profile is also device specific, however it doesn't + * contain an AToB0 tag that is open to misinterpretation. Almost + * certainly it will fail the tests below. + */ + (void)png_icc_profile_error(png_ptr, NULL, name, temp, + "unexpected NamedColor ICC profile class"); + break; + + default: + /* To allow for future enhancements to the profile accept unrecognized + * profile classes with a warning, these then hit the test below on the + * tag content to ensure they are backward compatible with one of the + * understood profiles. + */ + (void)png_icc_profile_error(png_ptr, NULL, name, temp, + "unrecognized ICC profile class"); + break; + } + + /* For any profile other than a device link one the PCS must be encoded + * either in XYZ or Lab. + */ + temp = png_get_uint_32(profile+20); + switch (temp) + { + case 0x58595a20: /* 'XYZ ' */ + case 0x4c616220: /* 'Lab ' */ + break; + + default: + return png_icc_profile_error(png_ptr, colorspace, name, temp, + "unexpected ICC PCS encoding"); + } + + return 1; +} + +int /* PRIVATE */ +png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length, + png_const_bytep profile /* header plus whole tag table */) +{ + png_uint_32 tag_count = png_get_uint_32(profile+128); + png_uint_32 itag; + png_const_bytep tag = profile+132; /* The first tag */ + + /* First scan all the tags in the table and add bits to the icc_info value + * (temporarily in 'tags'). + */ + for (itag=0; itag < tag_count; ++itag, tag += 12) + { + png_uint_32 tag_id = png_get_uint_32(tag+0); + png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */ + png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */ + + /* The ICC specification does not exclude zero length tags, therefore the + * start might actually be anywhere if there is no data, but this would be + * a clear abuse of the intent of the standard so the start is checked for + * being in range. All defined tag types have an 8 byte header - a 4 byte + * type signature then 0. + */ + if ((tag_start & 3) != 0) + { + /* CNHP730S.icc shipped with Microsoft Windows 64 violates this, it is + * only a warning here because libpng does not care about the + * alignment. + */ + (void)png_icc_profile_error(png_ptr, NULL, name, tag_id, + "ICC profile tag start not a multiple of 4"); + } + + /* This is a hard error; potentially it can cause read outside the + * profile. + */ + if (tag_start > profile_length || tag_length > profile_length - tag_start) + return png_icc_profile_error(png_ptr, colorspace, name, tag_id, + "ICC profile tag outside profile"); + } + + return 1; /* success, maybe with warnings */ +} + +#ifdef PNG_sRGB_SUPPORTED +#if PNG_sRGB_PROFILE_CHECKS >= 0 +/* Information about the known ICC sRGB profiles */ +static const struct +{ + png_uint_32 adler, crc, length; + png_uint_32 md5[4]; + png_byte have_md5; + png_byte is_broken; + png_uint_16 intent; + +# define PNG_MD5(a,b,c,d) { a, b, c, d }, (a!=0)||(b!=0)||(c!=0)||(d!=0) +# define PNG_ICC_CHECKSUM(adler, crc, md5, intent, broke, date, length, fname)\ + { adler, crc, length, md5, broke, intent }, + +} png_sRGB_checks[] = +{ + /* This data comes from contrib/tools/checksum-icc run on downloads of + * all four ICC sRGB profiles from www.color.org. + */ + /* adler32, crc32, MD5[4], intent, date, length, file-name */ + PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9, + PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0, + "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc") + + /* ICC sRGB v2 perceptual no black-compensation: */ + PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21, + PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0, + "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc") + + PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae, + PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0, + "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc") + + /* ICC sRGB v4 perceptual */ + PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812, + PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0, + "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc") + + /* The following profiles have no known MD5 checksum. If there is a match + * on the (empty) MD5 the other fields are used to attempt a match and + * a warning is produced. The first two of these profiles have a 'cprt' tag + * which suggests that they were also made by Hewlett Packard. + */ + PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce, + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0, + "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc") + + /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not + * match the D50 PCS illuminant in the header (it is in fact the D65 values, + * so the white point is recorded as the un-adapted value.) The profiles + * below only differ in one byte - the intent - and are basically the same as + * the previous profile except for the mediaWhitePointTag error and a missing + * chromaticAdaptationTag. + */ + PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552, + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/, + "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual") + + PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d, + PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/, + "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative") +}; + +static int +png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr, + png_const_bytep profile, uLong adler) +{ + /* The quick check is to verify just the MD5 signature and trust the + * rest of the data. Because the profile has already been verified for + * correctness this is safe. png_colorspace_set_sRGB will check the 'intent' + * field too, so if the profile has been edited with an intent not defined + * by sRGB (but maybe defined by a later ICC specification) the read of + * the profile will fail at that point. + */ + + png_uint_32 length = 0; + png_uint_32 intent = 0x10000; /* invalid */ +#if PNG_sRGB_PROFILE_CHECKS > 1 + uLong crc = 0; /* the value for 0 length data */ +#endif + unsigned int i; + +#ifdef PNG_SET_OPTION_SUPPORTED + /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */ + if (((png_ptr->options >> PNG_SKIP_sRGB_CHECK_PROFILE) & 3) == + PNG_OPTION_ON) + return 0; +#endif + + for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i) + { + if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] && + png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] && + png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] && + png_get_uint_32(profile+96) == png_sRGB_checks[i].md5[3]) + { + /* This may be one of the old HP profiles without an MD5, in that + * case we can only use the length and Adler32 (note that these + * are not used by default if there is an MD5!) + */ +# if PNG_sRGB_PROFILE_CHECKS == 0 + if (png_sRGB_checks[i].have_md5 != 0) + return 1+png_sRGB_checks[i].is_broken; +# endif + + /* Profile is unsigned or more checks have been configured in. */ + if (length == 0) + { + length = png_get_uint_32(profile); + intent = png_get_uint_32(profile+64); + } + + /* Length *and* intent must match */ + if (length == (png_uint_32) png_sRGB_checks[i].length && + intent == (png_uint_32) png_sRGB_checks[i].intent) + { + /* Now calculate the adler32 if not done already. */ + if (adler == 0) + { + adler = adler32(0, NULL, 0); + adler = adler32(adler, profile, length); + } + + if (adler == png_sRGB_checks[i].adler) + { + /* These basic checks suggest that the data has not been + * modified, but if the check level is more than 1 perform + * our own crc32 checksum on the data. + */ +# if PNG_sRGB_PROFILE_CHECKS > 1 + if (crc == 0) + { + crc = crc32(0, NULL, 0); + crc = crc32(crc, profile, length); + } + + /* So this check must pass for the 'return' below to happen. + */ + if (crc == png_sRGB_checks[i].crc) +# endif + { + if (png_sRGB_checks[i].is_broken != 0) + { + /* These profiles are known to have bad data that may cause + * problems if they are used, therefore attempt to + * discourage their use, skip the 'have_md5' warning below, + * which is made irrelevant by this error. + */ + png_chunk_report(png_ptr, "known incorrect sRGB profile", + PNG_CHUNK_ERROR); + } + + /* Warn that this being done; this isn't even an error since + * the profile is perfectly valid, but it would be nice if + * people used the up-to-date ones. + */ + else if (png_sRGB_checks[i].have_md5 == 0) + { + png_chunk_report(png_ptr, + "out-of-date sRGB profile with no signature", + PNG_CHUNK_WARNING); + } + + return 1+png_sRGB_checks[i].is_broken; + } + } + +# if PNG_sRGB_PROFILE_CHECKS > 0 + /* The signature matched, but the profile had been changed in some + * way. This probably indicates a data error or uninformed hacking. + * Fall through to "no match". + */ + png_chunk_report(png_ptr, + "Not recognizing known sRGB profile that has been edited", + PNG_CHUNK_WARNING); + break; +# endif + } + } + } + + return 0; /* no match */ +} +#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */ + +void /* PRIVATE */ +png_icc_set_sRGB(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_bytep profile, uLong adler) +{ + /* Is this profile one of the known ICC sRGB profiles? If it is, just set + * the sRGB information. + */ +#if PNG_sRGB_PROFILE_CHECKS >= 0 + if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0) +#endif + (void)png_colorspace_set_sRGB(png_ptr, colorspace, + (int)/*already checked*/png_get_uint_32(profile+64)); +} +#endif /* sRGB */ + +int /* PRIVATE */ +png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_charp name, png_uint_32 profile_length, png_const_bytep profile, + int color_type) +{ + if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0) + return 0; + + if (png_icc_check_length(png_ptr, colorspace, name, profile_length) != 0 && + png_icc_check_header(png_ptr, colorspace, name, profile_length, profile, + color_type) != 0 && + png_icc_check_tag_table(png_ptr, colorspace, name, profile_length, + profile) != 0) + { +# ifdef PNG_sRGB_SUPPORTED + /* If no sRGB support, don't try storing sRGB information */ + png_icc_set_sRGB(png_ptr, colorspace, profile, 0); +# endif + return 1; + } + + /* Failure case */ + return 0; +} +#endif /* iCCP */ + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +void /* PRIVATE */ +png_colorspace_set_rgb_coefficients(png_structrp png_ptr) +{ + /* Set the rgb_to_gray coefficients from the colorspace. */ + if (png_ptr->rgb_to_gray_coefficients_set == 0 && + (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + /* png_set_background has not been called, get the coefficients from the Y + * values of the colorspace colorants. + */ + png_fixed_point r = png_ptr->colorspace.end_points_XYZ.red_Y; + png_fixed_point g = png_ptr->colorspace.end_points_XYZ.green_Y; + png_fixed_point b = png_ptr->colorspace.end_points_XYZ.blue_Y; + png_fixed_point total = r+g+b; + + if (total > 0 && + r >= 0 && png_muldiv(&r, r, 32768, total) && r >= 0 && r <= 32768 && + g >= 0 && png_muldiv(&g, g, 32768, total) && g >= 0 && g <= 32768 && + b >= 0 && png_muldiv(&b, b, 32768, total) && b >= 0 && b <= 32768 && + r+g+b <= 32769) + { + /* We allow 0 coefficients here. r+g+b may be 32769 if two or + * all of the coefficients were rounded up. Handle this by + * reducing the *largest* coefficient by 1; this matches the + * approach used for the default coefficients in pngrtran.c + */ + int add = 0; + + if (r+g+b > 32768) + add = -1; + else if (r+g+b < 32768) + add = 1; + + if (add != 0) + { + if (g >= r && g >= b) + g += add; + else if (r >= g && r >= b) + r += add; + else + b += add; + } + + /* Check for an internal error. */ + if (r+g+b != 32768) + png_error(png_ptr, + "internal error handling cHRM coefficients"); + + else + { + png_ptr->rgb_to_gray_red_coeff = (png_uint_16)r; + png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g; + } + } + + /* This is a png_error at present even though it could be ignored - + * it should never happen, but it is important that if it does, the + * bug is fixed. + */ + else + png_error(png_ptr, "internal error handling cHRM->XYZ"); + } +} +#endif /* READ_RGB_TO_GRAY */ + +#endif /* COLORSPACE */ + +#ifdef __GNUC__ +/* This exists solely to work round a warning from GNU C. */ +static int /* PRIVATE */ +png_gt(size_t a, size_t b) +{ + return a > b; +} +#else +# define png_gt(a,b) ((a) > (b)) +#endif + +void /* PRIVATE */ +png_check_IHDR(png_const_structrp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) +{ + int error = 0; + + /* Check for width and height valid values */ + if (width == 0) + { + png_warning(png_ptr, "Image width is zero in IHDR"); + error = 1; + } + + if (width > PNG_UINT_31_MAX) + { + png_warning(png_ptr, "Invalid image width in IHDR"); + error = 1; + } + + if (png_gt(((width + 7) & (~7)), + ((PNG_SIZE_MAX + - 48 /* big_row_buf hack */ + - 1) /* filter byte */ + / 8) /* 8-byte RGBA pixels */ + - 1)) /* extra max_pixel_depth pad */ + { + /* The size of the row must be within the limits of this architecture. + * Because the read code can perform arbitrary transformations the + * maximum size is checked here. Because the code in png_read_start_row + * adds extra space "for safety's sake" in several places a conservative + * limit is used here. + * + * NOTE: it would be far better to check the size that is actually used, + * but the effect in the real world is minor and the changes are more + * extensive, therefore much more dangerous and much more difficult to + * write in a way that avoids compiler warnings. + */ + png_warning(png_ptr, "Image width is too large for this architecture"); + error = 1; + } + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (width > png_ptr->user_width_max) +#else + if (width > PNG_USER_WIDTH_MAX) +#endif + { + png_warning(png_ptr, "Image width exceeds user limit in IHDR"); + error = 1; + } + + if (height == 0) + { + png_warning(png_ptr, "Image height is zero in IHDR"); + error = 1; + } + + if (height > PNG_UINT_31_MAX) + { + png_warning(png_ptr, "Invalid image height in IHDR"); + error = 1; + } + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (height > png_ptr->user_height_max) +#else + if (height > PNG_USER_HEIGHT_MAX) +#endif + { + png_warning(png_ptr, "Image height exceeds user limit in IHDR"); + error = 1; + } + + /* Check other values */ + if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && + bit_depth != 8 && bit_depth != 16) + { + png_warning(png_ptr, "Invalid bit depth in IHDR"); + error = 1; + } + + if (color_type < 0 || color_type == 1 || + color_type == 5 || color_type > 6) + { + png_warning(png_ptr, "Invalid color type in IHDR"); + error = 1; + } + + if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) || + ((color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) + { + png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR"); + error = 1; + } + + if (interlace_type >= PNG_INTERLACE_LAST) + { + png_warning(png_ptr, "Unknown interlace method in IHDR"); + error = 1; + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Unknown compression method in IHDR"); + error = 1; + } + +#ifdef PNG_MNG_FEATURES_SUPPORTED + /* Accept filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not read a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && + png_ptr->mng_features_permitted != 0) + png_warning(png_ptr, "MNG features are not allowed in a PNG datastream"); + + if (filter_type != PNG_FILTER_TYPE_BASE) + { + if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING) && + ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA))) + { + png_warning(png_ptr, "Unknown filter method in IHDR"); + error = 1; + } + + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0) + { + png_warning(png_ptr, "Invalid filter method in IHDR"); + error = 1; + } + } + +#else + if (filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Unknown filter method in IHDR"); + error = 1; + } +#endif + + if (error == 1) + png_error(png_ptr, "Invalid IHDR data"); +} + +#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) +/* ASCII to fp functions */ +/* Check an ASCII formated floating point value, see the more detailed + * comments in pngpriv.h + */ +/* The following is used internally to preserve the sticky flags */ +#define png_fp_add(state, flags) ((state) |= (flags)) +#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY)) + +int /* PRIVATE */ +png_check_fp_number(png_const_charp string, png_size_t size, int *statep, + png_size_tp whereami) +{ + int state = *statep; + png_size_t i = *whereami; + + while (i < size) + { + int type; + /* First find the type of the next character */ + switch (string[i]) + { + case 43: type = PNG_FP_SAW_SIGN; break; + case 45: type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break; + case 46: type = PNG_FP_SAW_DOT; break; + case 48: type = PNG_FP_SAW_DIGIT; break; + case 49: case 50: case 51: case 52: + case 53: case 54: case 55: case 56: + case 57: type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break; + case 69: + case 101: type = PNG_FP_SAW_E; break; + default: goto PNG_FP_End; + } + + /* Now deal with this type according to the current + * state, the type is arranged to not overlap the + * bits of the PNG_FP_STATE. + */ + switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY)) + { + case PNG_FP_INTEGER + PNG_FP_SAW_SIGN: + if ((state & PNG_FP_SAW_ANY) != 0) + goto PNG_FP_End; /* not a part of the number */ + + png_fp_add(state, type); + break; + + case PNG_FP_INTEGER + PNG_FP_SAW_DOT: + /* Ok as trailer, ok as lead of fraction. */ + if ((state & PNG_FP_SAW_DOT) != 0) /* two dots */ + goto PNG_FP_End; + + else if ((state & PNG_FP_SAW_DIGIT) != 0) /* trailing dot? */ + png_fp_add(state, type); + + else + png_fp_set(state, PNG_FP_FRACTION | type); + + break; + + case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT: + if ((state & PNG_FP_SAW_DOT) != 0) /* delayed fraction */ + png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT); + + png_fp_add(state, type | PNG_FP_WAS_VALID); + + break; + + case PNG_FP_INTEGER + PNG_FP_SAW_E: + if ((state & PNG_FP_SAW_DIGIT) == 0) + goto PNG_FP_End; + + png_fp_set(state, PNG_FP_EXPONENT); + + break; + + /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN: + goto PNG_FP_End; ** no sign in fraction */ + + /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT: + goto PNG_FP_End; ** Because SAW_DOT is always set */ + + case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT: + png_fp_add(state, type | PNG_FP_WAS_VALID); + break; + + case PNG_FP_FRACTION + PNG_FP_SAW_E: + /* This is correct because the trailing '.' on an + * integer is handled above - so we can only get here + * with the sequence ".E" (with no preceding digits). + */ + if ((state & PNG_FP_SAW_DIGIT) == 0) + goto PNG_FP_End; + + png_fp_set(state, PNG_FP_EXPONENT); + + break; + + case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN: + if ((state & PNG_FP_SAW_ANY) != 0) + goto PNG_FP_End; /* not a part of the number */ + + png_fp_add(state, PNG_FP_SAW_SIGN); + + break; + + /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT: + goto PNG_FP_End; */ + + case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT: + png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID); + + break; + + /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E: + goto PNG_FP_End; */ + + default: goto PNG_FP_End; /* I.e. break 2 */ + } + + /* The character seems ok, continue. */ + ++i; + } + +PNG_FP_End: + /* Here at the end, update the state and return the correct + * return code. + */ + *statep = state; + *whereami = i; + + return (state & PNG_FP_SAW_DIGIT) != 0; +} + + +/* The same but for a complete string. */ +int +png_check_fp_string(png_const_charp string, png_size_t size) +{ + int state=0; + png_size_t char_index=0; + + if (png_check_fp_number(string, size, &state, &char_index) != 0 && + (char_index == size || string[char_index] == 0)) + return state /* must be non-zero - see above */; + + return 0; /* i.e. fail */ +} +#endif /* pCAL || sCAL */ + +#ifdef PNG_sCAL_SUPPORTED +# ifdef PNG_FLOATING_POINT_SUPPORTED +/* Utility used below - a simple accurate power of ten from an integral + * exponent. + */ +static double +png_pow10(int power) +{ + int recip = 0; + double d = 1; + + /* Handle negative exponent with a reciprocal at the end because + * 10 is exact whereas .1 is inexact in base 2 + */ + if (power < 0) + { + if (power < DBL_MIN_10_EXP) return 0; + recip = 1, power = -power; + } + + if (power > 0) + { + /* Decompose power bitwise. */ + double mult = 10; + do + { + if (power & 1) d *= mult; + mult *= mult; + power >>= 1; + } + while (power > 0); + + if (recip != 0) d = 1/d; + } + /* else power is 0 and d is 1 */ + + return d; +} + +/* Function to format a floating point value in ASCII with a given + * precision. + */ +void /* PRIVATE */ +png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size, + double fp, unsigned int precision) +{ + /* We use standard functions from math.h, but not printf because + * that would require stdio. The caller must supply a buffer of + * sufficient size or we will png_error. The tests on size and + * the space in ascii[] consumed are indicated below. + */ + if (precision < 1) + precision = DBL_DIG; + + /* Enforce the limit of the implementation precision too. */ + if (precision > DBL_DIG+1) + precision = DBL_DIG+1; + + /* Basic sanity checks */ + if (size >= precision+5) /* See the requirements below. */ + { + if (fp < 0) + { + fp = -fp; + *ascii++ = 45; /* '-' PLUS 1 TOTAL 1 */ + --size; + } + + if (fp >= DBL_MIN && fp <= DBL_MAX) + { + int exp_b10; /* A base 10 exponent */ + double base; /* 10^exp_b10 */ + + /* First extract a base 10 exponent of the number, + * the calculation below rounds down when converting + * from base 2 to base 10 (multiply by log10(2) - + * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to + * be increased. Note that the arithmetic shift + * performs a floor() unlike C arithmetic - using a + * C multiply would break the following for negative + * exponents. + */ + (void)frexp(fp, &exp_b10); /* exponent to base 2 */ + + exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */ + + /* Avoid underflow here. */ + base = png_pow10(exp_b10); /* May underflow */ + + while (base < DBL_MIN || base < fp) + { + /* And this may overflow. */ + double test = png_pow10(exp_b10+1); + + if (test <= DBL_MAX) + ++exp_b10, base = test; + + else + break; + } + + /* Normalize fp and correct exp_b10, after this fp is in the + * range [.1,1) and exp_b10 is both the exponent and the digit + * *before* which the decimal point should be inserted + * (starting with 0 for the first digit). Note that this + * works even if 10^exp_b10 is out of range because of the + * test on DBL_MAX above. + */ + fp /= base; + while (fp >= 1) fp /= 10, ++exp_b10; + + /* Because of the code above fp may, at this point, be + * less than .1, this is ok because the code below can + * handle the leading zeros this generates, so no attempt + * is made to correct that here. + */ + + { + unsigned int czero, clead, cdigits; + char exponent[10]; + + /* Allow up to two leading zeros - this will not lengthen + * the number compared to using E-n. + */ + if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */ + { + czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */ + exp_b10 = 0; /* Dot added below before first output. */ + } + else + czero = 0; /* No zeros to add */ + + /* Generate the digit list, stripping trailing zeros and + * inserting a '.' before a digit if the exponent is 0. + */ + clead = czero; /* Count of leading zeros */ + cdigits = 0; /* Count of digits in list. */ + + do + { + double d; + + fp *= 10; + /* Use modf here, not floor and subtract, so that + * the separation is done in one step. At the end + * of the loop don't break the number into parts so + * that the final digit is rounded. + */ + if (cdigits+czero+1 < precision+clead) + fp = modf(fp, &d); + + else + { + d = floor(fp + .5); + + if (d > 9) + { + /* Rounding up to 10, handle that here. */ + if (czero > 0) + { + --czero, d = 1; + if (cdigits == 0) --clead; + } + else + { + while (cdigits > 0 && d > 9) + { + int ch = *--ascii; + + if (exp_b10 != (-1)) + ++exp_b10; + + else if (ch == 46) + { + ch = *--ascii, ++size; + /* Advance exp_b10 to '1', so that the + * decimal point happens after the + * previous digit. + */ + exp_b10 = 1; + } + + --cdigits; + d = ch - 47; /* I.e. 1+(ch-48) */ + } + + /* Did we reach the beginning? If so adjust the + * exponent but take into account the leading + * decimal point. + */ + if (d > 9) /* cdigits == 0 */ + { + if (exp_b10 == (-1)) + { + /* Leading decimal point (plus zeros?), if + * we lose the decimal point here it must + * be reentered below. + */ + int ch = *--ascii; + + if (ch == 46) + ++size, exp_b10 = 1; + + /* Else lost a leading zero, so 'exp_b10' is + * still ok at (-1) + */ + } + else + ++exp_b10; + + /* In all cases we output a '1' */ + d = 1; + } + } + } + fp = 0; /* Guarantees termination below. */ + } + + if (d == 0) + { + ++czero; + if (cdigits == 0) ++clead; + } + else + { + /* Included embedded zeros in the digit count. */ + cdigits += czero - clead; + clead = 0; + + while (czero > 0) + { + /* exp_b10 == (-1) means we just output the decimal + * place - after the DP don't adjust 'exp_b10' any + * more! + */ + if (exp_b10 != (-1)) + { + if (exp_b10 == 0) *ascii++ = 46, --size; + /* PLUS 1: TOTAL 4 */ + --exp_b10; + } + *ascii++ = 48, --czero; + } + + if (exp_b10 != (-1)) + { + if (exp_b10 == 0) + *ascii++ = 46, --size; /* counted above */ + + --exp_b10; + } + *ascii++ = (char)(48 + (int)d), ++cdigits; + } + } + while (cdigits+czero < precision+clead && fp > DBL_MIN); + + /* The total output count (max) is now 4+precision */ + + /* Check for an exponent, if we don't need one we are + * done and just need to terminate the string. At + * this point exp_b10==(-1) is effectively if flag - it got + * to '-1' because of the decrement after outputting + * the decimal point above (the exponent required is + * *not* -1!) + */ + if (exp_b10 >= (-1) && exp_b10 <= 2) + { + /* The following only happens if we didn't output the + * leading zeros above for negative exponent, so this + * doesn't add to the digit requirement. Note that the + * two zeros here can only be output if the two leading + * zeros were *not* output, so this doesn't increase + * the output count. + */ + while (--exp_b10 >= 0) *ascii++ = 48; + + *ascii = 0; + + /* Total buffer requirement (including the '\0') is + * 5+precision - see check at the start. + */ + return; + } + + /* Here if an exponent is required, adjust size for + * the digits we output but did not count. The total + * digit output here so far is at most 1+precision - no + * decimal point and no leading or trailing zeros have + * been output. + */ + size -= cdigits; + + *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision */ + + /* The following use of an unsigned temporary avoids ambiguities in + * the signed arithmetic on exp_b10 and permits GCC at least to do + * better optimization. + */ + { + unsigned int uexp_b10; + + if (exp_b10 < 0) + { + *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */ + uexp_b10 = -exp_b10; + } + + else + uexp_b10 = exp_b10; + + cdigits = 0; + + while (uexp_b10 > 0) + { + exponent[cdigits++] = (char)(48 + uexp_b10 % 10); + uexp_b10 /= 10; + } + } + + /* Need another size check here for the exponent digits, so + * this need not be considered above. + */ + if (size > cdigits) + { + while (cdigits > 0) *ascii++ = exponent[--cdigits]; + + *ascii = 0; + + return; + } + } + } + else if (!(fp >= DBL_MIN)) + { + *ascii++ = 48; /* '0' */ + *ascii = 0; + return; + } + else + { + *ascii++ = 105; /* 'i' */ + *ascii++ = 110; /* 'n' */ + *ascii++ = 102; /* 'f' */ + *ascii = 0; + return; + } + } + + /* Here on buffer too small. */ + png_error(png_ptr, "ASCII conversion buffer too small"); +} + +# endif /* FLOATING_POINT */ + +# ifdef PNG_FIXED_POINT_SUPPORTED +/* Function to format a fixed point value in ASCII. + */ +void /* PRIVATE */ +png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii, + png_size_t size, png_fixed_point fp) +{ + /* Require space for 10 decimal digits, a decimal point, a minus sign and a + * trailing \0, 13 characters: + */ + if (size > 12) + { + png_uint_32 num; + + /* Avoid overflow here on the minimum integer. */ + if (fp < 0) + *ascii++ = 45, num = -fp; + else + num = fp; + + if (num <= 0x80000000) /* else overflowed */ + { + unsigned int ndigits = 0, first = 16 /* flag value */; + char digits[10]; + + while (num) + { + /* Split the low digit off num: */ + unsigned int tmp = num/10; + num -= tmp*10; + digits[ndigits++] = (char)(48 + num); + /* Record the first non-zero digit, note that this is a number + * starting at 1, it's not actually the array index. + */ + if (first == 16 && num > 0) + first = ndigits; + num = tmp; + } + + if (ndigits > 0) + { + while (ndigits > 5) *ascii++ = digits[--ndigits]; + /* The remaining digits are fractional digits, ndigits is '5' or + * smaller at this point. It is certainly not zero. Check for a + * non-zero fractional digit: + */ + if (first <= 5) + { + unsigned int i; + *ascii++ = 46; /* decimal point */ + /* ndigits may be <5 for small numbers, output leading zeros + * then ndigits digits to first: + */ + i = 5; + while (ndigits < i) *ascii++ = 48, --i; + while (ndigits >= first) *ascii++ = digits[--ndigits]; + /* Don't output the trailing zeros! */ + } + } + else + *ascii++ = 48; + + /* And null terminate the string: */ + *ascii = 0; + return; + } + } + + /* Here on buffer too small. */ + png_error(png_ptr, "ASCII conversion buffer too small"); +} +# endif /* FIXED_POINT */ +#endif /* SCAL */ + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ + !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \ + (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \ + defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \ + (defined(PNG_sCAL_SUPPORTED) && \ + defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)) +png_fixed_point +png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text) +{ + double r = floor(100000 * fp + .5); + + if (r > 2147483647. || r < -2147483648.) + png_fixed_error(png_ptr, text); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(text) +# endif + + return (png_fixed_point)r; +} +#endif + +#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_COLORSPACE_SUPPORTED) ||\ + defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) +/* muldiv functions */ +/* This API takes signed arguments and rounds the result to the nearest + * integer (or, for a fixed point number - the standard argument - to + * the nearest .00001). Overflow and divide by zero are signalled in + * the result, a boolean - true on success, false on overflow. + */ +int +png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, + png_int_32 divisor) +{ + /* Return a * times / divisor, rounded. */ + if (divisor != 0) + { + if (a == 0 || times == 0) + { + *res = 0; + return 1; + } + else + { +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = a; + r *= times; + r /= divisor; + r = floor(r+.5); + + /* A png_fixed_point is a 32-bit integer. */ + if (r <= 2147483647. && r >= -2147483648.) + { + *res = (png_fixed_point)r; + return 1; + } +#else + int negative = 0; + png_uint_32 A, T, D; + png_uint_32 s16, s32, s00; + + if (a < 0) + negative = 1, A = -a; + else + A = a; + + if (times < 0) + negative = !negative, T = -times; + else + T = times; + + if (divisor < 0) + negative = !negative, D = -divisor; + else + D = divisor; + + /* Following can't overflow because the arguments only + * have 31 bits each, however the result may be 32 bits. + */ + s16 = (A >> 16) * (T & 0xffff) + + (A & 0xffff) * (T >> 16); + /* Can't overflow because the a*times bit is only 30 + * bits at most. + */ + s32 = (A >> 16) * (T >> 16) + (s16 >> 16); + s00 = (A & 0xffff) * (T & 0xffff); + + s16 = (s16 & 0xffff) << 16; + s00 += s16; + + if (s00 < s16) + ++s32; /* carry */ + + if (s32 < D) /* else overflow */ + { + /* s32.s00 is now the 64-bit product, do a standard + * division, we know that s32 < D, so the maximum + * required shift is 31. + */ + int bitshift = 32; + png_fixed_point result = 0; /* NOTE: signed */ + + while (--bitshift >= 0) + { + png_uint_32 d32, d00; + + if (bitshift > 0) + d32 = D >> (32-bitshift), d00 = D << bitshift; + + else + d32 = 0, d00 = D; + + if (s32 > d32) + { + if (s00 < d00) --s32; /* carry */ + s32 -= d32, s00 -= d00, result += 1<<bitshift; + } + + else + if (s32 == d32 && s00 >= d00) + s32 = 0, s00 -= d00, result += 1<<bitshift; + } + + /* Handle the rounding. */ + if (s00 >= (D >> 1)) + ++result; + + if (negative != 0) + result = -result; + + /* Check for overflow. */ + if ((negative != 0 && result <= 0) || + (negative == 0 && result >= 0)) + { + *res = result; + return 1; + } + } +#endif + } + } + + return 0; +} +#endif /* READ_GAMMA || INCH_CONVERSIONS */ + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) +/* The following is for when the caller doesn't much care about the + * result. + */ +png_fixed_point +png_muldiv_warn(png_const_structrp png_ptr, png_fixed_point a, png_int_32 times, + png_int_32 divisor) +{ + png_fixed_point result; + + if (png_muldiv(&result, a, times, divisor) != 0) + return result; + + png_warning(png_ptr, "fixed point overflow ignored"); + return 0; +} +#endif + +#ifdef PNG_GAMMA_SUPPORTED /* more fixed point functions for gamma */ +/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */ +png_fixed_point +png_reciprocal(png_fixed_point a) +{ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = floor(1E10/a+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; +#else + png_fixed_point res; + + if (png_muldiv(&res, 100000, 100000, a) != 0) + return res; +#endif + + return 0; /* error/overflow */ +} + +/* This is the shared test on whether a gamma value is 'significant' - whether + * it is worth doing gamma correction. + */ +int /* PRIVATE */ +png_gamma_significant(png_fixed_point gamma_val) +{ + return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED || + gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED; +} +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +#ifdef PNG_16BIT_SUPPORTED +/* A local convenience routine. */ +static png_fixed_point +png_product2(png_fixed_point a, png_fixed_point b) +{ + /* The required result is 1/a * 1/b; the following preserves accuracy. */ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = a * 1E-5; + r *= b; + r = floor(r+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; +#else + png_fixed_point res; + + if (png_muldiv(&res, a, b, 100000) != 0) + return res; +#endif + + return 0; /* overflow */ +} +#endif /* 16BIT */ + +/* The inverse of the above. */ +png_fixed_point +png_reciprocal2(png_fixed_point a, png_fixed_point b) +{ + /* The required result is 1/a * 1/b; the following preserves accuracy. */ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + if (a != 0 && b != 0) + { + double r = 1E15/a; + r /= b; + r = floor(r+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; + } +#else + /* This may overflow because the range of png_fixed_point isn't symmetric, + * but this API is only used for the product of file and screen gamma so it + * doesn't matter that the smallest number it can produce is 1/21474, not + * 1/100000 + */ + png_fixed_point res = png_product2(a, b); + + if (res != 0) + return png_reciprocal(res); +#endif + + return 0; /* overflow */ +} +#endif /* READ_GAMMA */ + +#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */ +#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED +/* Fixed point gamma. + * + * The code to calculate the tables used below can be found in the shell script + * contrib/tools/intgamma.sh + * + * To calculate gamma this code implements fast log() and exp() calls using only + * fixed point arithmetic. This code has sufficient precision for either 8-bit + * or 16-bit sample values. + * + * The tables used here were calculated using simple 'bc' programs, but C double + * precision floating point arithmetic would work fine. + * + * 8-bit log table + * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to + * 255, so it's the base 2 logarithm of a normalized 8-bit floating point + * mantissa. The numbers are 32-bit fractions. + */ +static const png_uint_32 +png_8bit_l2[128] = +{ + 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U, + 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U, + 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U, + 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U, + 3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U, + 2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U, + 2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U, + 2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U, + 2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U, + 2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U, + 1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U, + 1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U, + 1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U, + 1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U, + 1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U, + 971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U, + 803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U, + 639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U, + 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U, + 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U, + 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U, + 24347096U, 0U + +#if 0 + /* The following are the values for 16-bit tables - these work fine for the + * 8-bit conversions but produce very slightly larger errors in the 16-bit + * log (about 1.2 as opposed to 0.7 absolute error in the final value). To + * use these all the shifts below must be adjusted appropriately. + */ + 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054, + 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803, + 50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068, + 43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782, + 37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887, + 31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339, + 25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098, + 20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132, + 15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415, + 10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523, + 6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495, + 1119, 744, 372 +#endif +}; + +static png_int_32 +png_log8bit(unsigned int x) +{ + unsigned int lg2 = 0; + /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log, + * because the log is actually negate that means adding 1. The final + * returned value thus has the range 0 (for 255 input) to 7.994 (for 1 + * input), return -1 for the overflow (log 0) case, - so the result is + * always at most 19 bits. + */ + if ((x &= 0xff) == 0) + return -1; + + if ((x & 0xf0) == 0) + lg2 = 4, x <<= 4; + + if ((x & 0xc0) == 0) + lg2 += 2, x <<= 2; + + if ((x & 0x80) == 0) + lg2 += 1, x <<= 1; + + /* result is at most 19 bits, so this cast is safe: */ + return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16)); +} + +/* The above gives exact (to 16 binary places) log2 values for 8-bit images, + * for 16-bit images we use the most significant 8 bits of the 16-bit value to + * get an approximation then multiply the approximation by a correction factor + * determined by the remaining up to 8 bits. This requires an additional step + * in the 16-bit case. + * + * We want log2(value/65535), we have log2(v'/255), where: + * + * value = v' * 256 + v'' + * = v' * f + * + * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128 + * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less + * than 258. The final factor also needs to correct for the fact that our 8-bit + * value is scaled by 255, whereas the 16-bit values must be scaled by 65535. + * + * This gives a final formula using a calculated value 'x' which is value/v' and + * scaling by 65536 to match the above table: + * + * log2(x/257) * 65536 + * + * Since these numbers are so close to '1' we can use simple linear + * interpolation between the two end values 256/257 (result -368.61) and 258/257 + * (result 367.179). The values used below are scaled by a further 64 to give + * 16-bit precision in the interpolation: + * + * Start (256): -23591 + * Zero (257): 0 + * End (258): 23499 + */ +#ifdef PNG_16BIT_SUPPORTED +static png_int_32 +png_log16bit(png_uint_32 x) +{ + unsigned int lg2 = 0; + + /* As above, but now the input has 16 bits. */ + if ((x &= 0xffff) == 0) + return -1; + + if ((x & 0xff00) == 0) + lg2 = 8, x <<= 8; + + if ((x & 0xf000) == 0) + lg2 += 4, x <<= 4; + + if ((x & 0xc000) == 0) + lg2 += 2, x <<= 2; + + if ((x & 0x8000) == 0) + lg2 += 1, x <<= 1; + + /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional + * value. + */ + lg2 <<= 28; + lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4; + + /* Now we need to interpolate the factor, this requires a division by the top + * 8 bits. Do this with maximum precision. + */ + x = ((x << 16) + (x >> 9)) / (x >> 8); + + /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24, + * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly + * 16 bits to interpolate to get the low bits of the result. Round the + * answer. Note that the end point values are scaled by 64 to retain overall + * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust + * the overall scaling by 6-12. Round at every step. + */ + x -= 1U << 24; + + if (x <= 65536U) /* <= '257' */ + lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12); + + else + lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12); + + /* Safe, because the result can't have more than 20 bits: */ + return (png_int_32)((lg2 + 2048) >> 12); +} +#endif /* 16BIT */ + +/* The 'exp()' case must invert the above, taking a 20-bit fixed point + * logarithmic value and returning a 16 or 8-bit number as appropriate. In + * each case only the low 16 bits are relevant - the fraction - since the + * integer bits (the top 4) simply determine a shift. + * + * The worst case is the 16-bit distinction between 65535 and 65534. This + * requires perhaps spurious accuracy in the decoding of the logarithm to + * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance + * of getting this accuracy in practice. + * + * To deal with this the following exp() function works out the exponent of the + * frational part of the logarithm by using an accurate 32-bit value from the + * top four fractional bits then multiplying in the remaining bits. + */ +static const png_uint_32 +png_32bit_exp[16] = +{ + /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */ + 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U, + 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U, + 2553802834U, 2445529972U, 2341847524U, 2242560872U +}; + +/* Adjustment table; provided to explain the numbers in the code below. */ +#if 0 +for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"} + 11 44937.64284865548751208448 + 10 45180.98734845585101160448 + 9 45303.31936980687359311872 + 8 45364.65110595323018870784 + 7 45395.35850361789624614912 + 6 45410.72259715102037508096 + 5 45418.40724413220722311168 + 4 45422.25021786898173001728 + 3 45424.17186732298419044352 + 2 45425.13273269940811464704 + 1 45425.61317555035558641664 + 0 45425.85339951654943850496 +#endif + +static png_uint_32 +png_exp(png_fixed_point x) +{ + if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */ + { + /* Obtain a 4-bit approximation */ + png_uint_32 e = png_32bit_exp[(x >> 12) & 0x0f]; + + /* Incorporate the low 12 bits - these decrease the returned value by + * multiplying by a number less than 1 if the bit is set. The multiplier + * is determined by the above table and the shift. Notice that the values + * converge on 45426 and this is used to allow linear interpolation of the + * low bits. + */ + if (x & 0x800) + e -= (((e >> 16) * 44938U) + 16U) >> 5; + + if (x & 0x400) + e -= (((e >> 16) * 45181U) + 32U) >> 6; + + if (x & 0x200) + e -= (((e >> 16) * 45303U) + 64U) >> 7; + + if (x & 0x100) + e -= (((e >> 16) * 45365U) + 128U) >> 8; + + if (x & 0x080) + e -= (((e >> 16) * 45395U) + 256U) >> 9; + + if (x & 0x040) + e -= (((e >> 16) * 45410U) + 512U) >> 10; + + /* And handle the low 6 bits in a single block. */ + e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9; + + /* Handle the upper bits of x. */ + e >>= x >> 16; + return e; + } + + /* Check for overflow */ + if (x <= 0) + return png_32bit_exp[0]; + + /* Else underflow */ + return 0; +} + +static png_byte +png_exp8bit(png_fixed_point lg2) +{ + /* Get a 32-bit value: */ + png_uint_32 x = png_exp(lg2); + + /* Convert the 32-bit value to 0..255 by multiplying by 256-1. Note that the + * second, rounding, step can't overflow because of the first, subtraction, + * step. + */ + x -= x >> 8; + return (png_byte)(((x + 0x7fffffU) >> 24) & 0xff); +} + +#ifdef PNG_16BIT_SUPPORTED +static png_uint_16 +png_exp16bit(png_fixed_point lg2) +{ + /* Get a 32-bit value: */ + png_uint_32 x = png_exp(lg2); + + /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */ + x -= x >> 16; + return (png_uint_16)((x + 32767U) >> 16); +} +#endif /* 16BIT */ +#endif /* FLOATING_ARITHMETIC */ + +png_byte +png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val) +{ + if (value > 0 && value < 255) + { +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* 'value' is unsigned, ANSI-C90 requires the compiler to correctly + * convert this to a floating point value. This includes values that + * would overflow if 'value' were to be converted to 'int'. + * + * Apparently GCC, however, does an intermediate conversion to (int) + * on some (ARM) but not all (x86) platforms, possibly because of + * hardware FP limitations. (E.g. if the hardware conversion always + * assumes the integer register contains a signed value.) This results + * in ANSI-C undefined behavior for large values. + * + * Other implementations on the same machine might actually be ANSI-C90 + * conformant and therefore compile spurious extra code for the large + * values. + * + * We can be reasonably sure that an unsigned to float conversion + * won't be faster than an int to float one. Therefore this code + * assumes responsibility for the undefined behavior, which it knows + * can't happen because of the check above. + * + * Note the argument to this routine is an (unsigned int) because, on + * 16-bit platforms, it is assigned a value which might be out of + * range for an (int); that would result in undefined behavior in the + * caller if the *argument* ('value') were to be declared (int). + */ + double r = floor(255*pow((int)/*SAFE*/value/255.,gamma_val*.00001)+.5); + return (png_byte)r; +# else + png_int_32 lg2 = png_log8bit(value); + png_fixed_point res; + + if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) + return png_exp8bit(res); + + /* Overflow. */ + value = 0; +# endif + } + + return (png_byte)(value & 0xff); +} + +#ifdef PNG_16BIT_SUPPORTED +png_uint_16 +png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val) +{ + if (value > 0 && value < 65535) + { +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* The same (unsigned int)->(double) constraints apply here as above, + * however in this case the (unsigned int) to (int) conversion can + * overflow on an ANSI-C90 compliant system so the cast needs to ensure + * that this is not possible. + */ + double r = floor(65535*pow((png_int_32)value/65535., + gamma_val*.00001)+.5); + return (png_uint_16)r; +# else + png_int_32 lg2 = png_log16bit(value); + png_fixed_point res; + + if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0) + return png_exp16bit(res); + + /* Overflow. */ + value = 0; +# endif + } + + return (png_uint_16)value; +} +#endif /* 16BIT */ + +/* This does the right thing based on the bit_depth field of the + * png_struct, interpreting values as 8-bit or 16-bit. While the result + * is nominally a 16-bit value if bit depth is 8 then the result is + * 8-bit (as are the arguments.) + */ +png_uint_16 /* PRIVATE */ +png_gamma_correct(png_structrp png_ptr, unsigned int value, + png_fixed_point gamma_val) +{ + if (png_ptr->bit_depth == 8) + return png_gamma_8bit_correct(value, gamma_val); + +#ifdef PNG_16BIT_SUPPORTED + else + return png_gamma_16bit_correct(value, gamma_val); +#else + /* should not reach this */ + return 0; +#endif /* 16BIT */ +} + +#ifdef PNG_16BIT_SUPPORTED +/* Internal function to build a single 16-bit table - the table consists of + * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount + * to shift the input values right (or 16-number_of_signifiant_bits). + * + * The caller is responsible for ensuring that the table gets cleaned up on + * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument + * should be somewhere that will be cleaned. + */ +static void +png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable, + PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) +{ + /* Various values derived from 'shift': */ + PNG_CONST unsigned int num = 1U << (8U - shift); +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* CSE the division and work round wacky GCC warnings (see the comments + * in png_gamma_8bit_correct for where these come from.) + */ + PNG_CONST double fmax = 1./(((png_int_32)1 << (16U - shift))-1); +#endif + PNG_CONST unsigned int max = (1U << (16U - shift))-1U; + PNG_CONST unsigned int max_by_2 = 1U << (15U-shift); + unsigned int i; + + png_uint_16pp table = *ptable = + (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p))); + + for (i = 0; i < num; i++) + { + png_uint_16p sub_table = table[i] = + (png_uint_16p)png_malloc(png_ptr, 256 * (sizeof (png_uint_16))); + + /* The 'threshold' test is repeated here because it can arise for one of + * the 16-bit tables even if the others don't hit it. + */ + if (png_gamma_significant(gamma_val) != 0) + { + /* The old code would overflow at the end and this would cause the + * 'pow' function to return a result >1, resulting in an + * arithmetic error. This code follows the spec exactly; ig is + * the recovered input sample, it always has 8-16 bits. + * + * We want input * 65535/max, rounded, the arithmetic fits in 32 + * bits (unsigned) so long as max <= 32767. + */ + unsigned int j; + for (j = 0; j < 256; j++) + { + png_uint_32 ig = (j << (8-shift)) + i; +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* Inline the 'max' scaling operation: */ + /* See png_gamma_8bit_correct for why the cast to (int) is + * required here. + */ + double d = floor(65535.*pow(ig*fmax, gamma_val*.00001)+.5); + sub_table[j] = (png_uint_16)d; +# else + if (shift != 0) + ig = (ig * 65535U + max_by_2)/max; + + sub_table[j] = png_gamma_16bit_correct(ig, gamma_val); +# endif + } + } + else + { + /* We must still build a table, but do it the fast way. */ + unsigned int j; + + for (j = 0; j < 256; j++) + { + png_uint_32 ig = (j << (8-shift)) + i; + + if (shift != 0) + ig = (ig * 65535U + max_by_2)/max; + + sub_table[j] = (png_uint_16)ig; + } + } + } +} + +/* NOTE: this function expects the *inverse* of the overall gamma transformation + * required. + */ +static void +png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable, + PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) +{ + PNG_CONST unsigned int num = 1U << (8U - shift); + PNG_CONST unsigned int max = (1U << (16U - shift))-1U; + unsigned int i; + png_uint_32 last; + + png_uint_16pp table = *ptable = + (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p))); + + /* 'num' is the number of tables and also the number of low bits of low + * bits of the input 16-bit value used to select a table. Each table is + * itself indexed by the high 8 bits of the value. + */ + for (i = 0; i < num; i++) + table[i] = (png_uint_16p)png_malloc(png_ptr, + 256 * (sizeof (png_uint_16))); + + /* 'gamma_val' is set to the reciprocal of the value calculated above, so + * pow(out,g) is an *input* value. 'last' is the last input value set. + * + * In the loop 'i' is used to find output values. Since the output is + * 8-bit there are only 256 possible values. The tables are set up to + * select the closest possible output value for each input by finding + * the input value at the boundary between each pair of output values + * and filling the table up to that boundary with the lower output + * value. + * + * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9-bit + * values the code below uses a 16-bit value in i; the values start at + * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last + * entries are filled with 255). Start i at 128 and fill all 'last' + * table entries <= 'max' + */ + last = 0; + for (i = 0; i < 255; ++i) /* 8-bit output value */ + { + /* Find the corresponding maximum input value */ + png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */ + + /* Find the boundary value in 16 bits: */ + png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val); + + /* Adjust (round) to (16-shift) bits: */ + bound = (bound * max + 32768U)/65535U + 1U; + + while (last < bound) + { + table[last & (0xffU >> shift)][last >> (8U - shift)] = out; + last++; + } + } + + /* And fill in the final entries. */ + while (last < (num << 8)) + { + table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U; + last++; + } +} +#endif /* 16BIT */ + +/* Build a single 8-bit table: same as the 16-bit case but much simpler (and + * typically much faster). Note that libpng currently does no sBIT processing + * (apparently contrary to the spec) so a 256-entry table is always generated. + */ +static void +png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable, + PNG_CONST png_fixed_point gamma_val) +{ + unsigned int i; + png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256); + + if (png_gamma_significant(gamma_val) != 0) + for (i=0; i<256; i++) + table[i] = png_gamma_8bit_correct(i, gamma_val); + + else + for (i=0; i<256; ++i) + table[i] = (png_byte)(i & 0xff); +} + +/* Used from png_read_destroy and below to release the memory used by the gamma + * tables. + */ +void /* PRIVATE */ +png_destroy_gamma_table(png_structrp png_ptr) +{ + png_free(png_ptr, png_ptr->gamma_table); + png_ptr->gamma_table = NULL; + +#ifdef PNG_16BIT_SUPPORTED + if (png_ptr->gamma_16_table != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_table[i]); + } + png_free(png_ptr, png_ptr->gamma_16_table); + png_ptr->gamma_16_table = NULL; + } +#endif /* 16BIT */ + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_from_1); + png_ptr->gamma_from_1 = NULL; + png_free(png_ptr, png_ptr->gamma_to_1); + png_ptr->gamma_to_1 = NULL; + +#ifdef PNG_16BIT_SUPPORTED + if (png_ptr->gamma_16_from_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_from_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_from_1); + png_ptr->gamma_16_from_1 = NULL; + } + if (png_ptr->gamma_16_to_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_to_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_to_1); + png_ptr->gamma_16_to_1 = NULL; + } +#endif /* 16BIT */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ +} + +/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit + * tables, we don't make a full table if we are reducing to 8-bit in + * the future. Note also how the gamma_16 tables are segmented so that + * we don't need to allocate > 64K chunks for a full 16-bit table. + */ +void /* PRIVATE */ +png_build_gamma_table(png_structrp png_ptr, int bit_depth) +{ + png_debug(1, "in png_build_gamma_table"); + + /* Remove any existing table; this copes with multiple calls to + * png_read_update_info. The warning is because building the gamma tables + * multiple times is a performance hit - it's harmless but the ability to call + * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible + * to warn if the app introduces such a hit. + */ + if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL) + { + png_warning(png_ptr, "gamma table being rebuilt"); + png_destroy_gamma_table(png_ptr); + } + + if (bit_depth <= 8) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_table, + png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, + png_reciprocal(png_ptr->colorspace.gamma)); + + png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1, + png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + } +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ + } +#ifdef PNG_16BIT_SUPPORTED + else + { + png_byte shift, sig_bit; + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + sig_bit = png_ptr->sig_bit.red; + + if (png_ptr->sig_bit.green > sig_bit) + sig_bit = png_ptr->sig_bit.green; + + if (png_ptr->sig_bit.blue > sig_bit) + sig_bit = png_ptr->sig_bit.blue; + } + else + sig_bit = png_ptr->sig_bit.gray; + + /* 16-bit gamma code uses this equation: + * + * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] + * + * Where 'iv' is the input color value and 'ov' is the output value - + * pow(iv, gamma). + * + * Thus the gamma table consists of up to 256 256-entry tables. The table + * is selected by the (8-gamma_shift) most significant of the low 8 bits of + * the color value then indexed by the upper 8 bits: + * + * table[low bits][high 8 bits] + * + * So the table 'n' corresponds to all those 'iv' of: + * + * <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> + * + */ + if (sig_bit > 0 && sig_bit < 16U) + /* shift == insignificant bits */ + shift = (png_byte)((16U - sig_bit) & 0xff); + + else + shift = 0; /* keep all 16 bits */ + + if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) + { + /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively + * the significant bits in the *input* when the output will + * eventually be 8 bits. By default it is 11. + */ + if (shift < (16U - PNG_MAX_GAMMA_8)) + shift = (16U - PNG_MAX_GAMMA_8); + } + + if (shift > 8U) + shift = 8U; /* Guarantees at least one table! */ + + png_ptr->gamma_shift = shift; + + /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now + * PNG_COMPOSE). This effectively smashed the background calculation for + * 16-bit output because the 8-bit table assumes the result will be reduced + * to 8 bits. + */ + if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0) + png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); + + else + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma) : PNG_FP_1); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0) + { + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, + png_reciprocal(png_ptr->colorspace.gamma)); + + /* Notice that the '16 from 1' table should be full precision, however + * the lookup on this table still uses gamma_shift, so it can't be. + * TODO: fix this. + */ + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : + png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */); + } +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ + } +#endif /* 16BIT */ +} +#endif /* READ_GAMMA */ + +/* HARDWARE OR SOFTWARE OPTION SUPPORT */ +#ifdef PNG_SET_OPTION_SUPPORTED +int PNGAPI +png_set_option(png_structrp png_ptr, int option, int onoff) +{ + if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT && + (option & 1) == 0) + { + int mask = 3 << option; + int setting = (2 + (onoff != 0)) << option; + int current = png_ptr->options; + + png_ptr->options = (png_byte)(((current & ~mask) | setting) & 0xff); + + return (current & mask) >> option; + } + + return PNG_OPTION_INVALID; +} +#endif + +/* sRGB support */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +/* sRGB conversion tables; these are machine generated with the code in + * contrib/tools/makesRGB.c. The actual sRGB transfer curve defined in the + * specification (see the article at http://en.wikipedia.org/wiki/SRGB) + * is used, not the gamma=1/2.2 approximation use elsewhere in libpng. + * The sRGB to linear table is exact (to the nearest 16-bit linear fraction). + * The inverse (linear to sRGB) table has accuracies as follows: + * + * For all possible (255*65535+1) input values: + * + * error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact + * + * For the input values corresponding to the 65536 16-bit values: + * + * error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact + * + * In all cases the inexact readings are only off by one. + */ + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +/* The convert-to-sRGB table is only currently required for read. */ +const png_uint_16 png_sRGB_table[256] = +{ + 0,20,40,60,80,99,119,139, + 159,179,199,219,241,264,288,313, + 340,367,396,427,458,491,526,562, + 599,637,677,718,761,805,851,898, + 947,997,1048,1101,1156,1212,1270,1330, + 1391,1453,1517,1583,1651,1720,1790,1863, + 1937,2013,2090,2170,2250,2333,2418,2504, + 2592,2681,2773,2866,2961,3058,3157,3258, + 3360,3464,3570,3678,3788,3900,4014,4129, + 4247,4366,4488,4611,4736,4864,4993,5124, + 5257,5392,5530,5669,5810,5953,6099,6246, + 6395,6547,6700,6856,7014,7174,7335,7500, + 7666,7834,8004,8177,8352,8528,8708,8889, + 9072,9258,9445,9635,9828,10022,10219,10417, + 10619,10822,11028,11235,11446,11658,11873,12090, + 12309,12530,12754,12980,13209,13440,13673,13909, + 14146,14387,14629,14874,15122,15371,15623,15878, + 16135,16394,16656,16920,17187,17456,17727,18001, + 18277,18556,18837,19121,19407,19696,19987,20281, + 20577,20876,21177,21481,21787,22096,22407,22721, + 23038,23357,23678,24002,24329,24658,24990,25325, + 25662,26001,26344,26688,27036,27386,27739,28094, + 28452,28813,29176,29542,29911,30282,30656,31033, + 31412,31794,32179,32567,32957,33350,33745,34143, + 34544,34948,35355,35764,36176,36591,37008,37429, + 37852,38278,38706,39138,39572,40009,40449,40891, + 41337,41785,42236,42690,43147,43606,44069,44534, + 45002,45473,45947,46423,46903,47385,47871,48359, + 48850,49344,49841,50341,50844,51349,51858,52369, + 52884,53401,53921,54445,54971,55500,56032,56567, + 57105,57646,58190,58737,59287,59840,60396,60955, + 61517,62082,62650,63221,63795,64372,64952,65535 +}; +#endif /* SIMPLIFIED_READ */ + +/* The base/delta tables are required for both read and write (but currently + * only the simplified versions.) + */ +const png_uint_16 png_sRGB_base[512] = +{ + 128,1782,3383,4644,5675,6564,7357,8074, + 8732,9346,9921,10463,10977,11466,11935,12384, + 12816,13233,13634,14024,14402,14769,15125,15473, + 15812,16142,16466,16781,17090,17393,17690,17981, + 18266,18546,18822,19093,19359,19621,19879,20133, + 20383,20630,20873,21113,21349,21583,21813,22041, + 22265,22487,22707,22923,23138,23350,23559,23767, + 23972,24175,24376,24575,24772,24967,25160,25352, + 25542,25730,25916,26101,26284,26465,26645,26823, + 27000,27176,27350,27523,27695,27865,28034,28201, + 28368,28533,28697,28860,29021,29182,29341,29500, + 29657,29813,29969,30123,30276,30429,30580,30730, + 30880,31028,31176,31323,31469,31614,31758,31902, + 32045,32186,32327,32468,32607,32746,32884,33021, + 33158,33294,33429,33564,33697,33831,33963,34095, + 34226,34357,34486,34616,34744,34873,35000,35127, + 35253,35379,35504,35629,35753,35876,35999,36122, + 36244,36365,36486,36606,36726,36845,36964,37083, + 37201,37318,37435,37551,37668,37783,37898,38013, + 38127,38241,38354,38467,38580,38692,38803,38915, + 39026,39136,39246,39356,39465,39574,39682,39790, + 39898,40005,40112,40219,40325,40431,40537,40642, + 40747,40851,40955,41059,41163,41266,41369,41471, + 41573,41675,41777,41878,41979,42079,42179,42279, + 42379,42478,42577,42676,42775,42873,42971,43068, + 43165,43262,43359,43456,43552,43648,43743,43839, + 43934,44028,44123,44217,44311,44405,44499,44592, + 44685,44778,44870,44962,45054,45146,45238,45329, + 45420,45511,45601,45692,45782,45872,45961,46051, + 46140,46229,46318,46406,46494,46583,46670,46758, + 46846,46933,47020,47107,47193,47280,47366,47452, + 47538,47623,47709,47794,47879,47964,48048,48133, + 48217,48301,48385,48468,48552,48635,48718,48801, + 48884,48966,49048,49131,49213,49294,49376,49458, + 49539,49620,49701,49782,49862,49943,50023,50103, + 50183,50263,50342,50422,50501,50580,50659,50738, + 50816,50895,50973,51051,51129,51207,51285,51362, + 51439,51517,51594,51671,51747,51824,51900,51977, + 52053,52129,52205,52280,52356,52432,52507,52582, + 52657,52732,52807,52881,52956,53030,53104,53178, + 53252,53326,53400,53473,53546,53620,53693,53766, + 53839,53911,53984,54056,54129,54201,54273,54345, + 54417,54489,54560,54632,54703,54774,54845,54916, + 54987,55058,55129,55199,55269,55340,55410,55480, + 55550,55620,55689,55759,55828,55898,55967,56036, + 56105,56174,56243,56311,56380,56448,56517,56585, + 56653,56721,56789,56857,56924,56992,57059,57127, + 57194,57261,57328,57395,57462,57529,57595,57662, + 57728,57795,57861,57927,57993,58059,58125,58191, + 58256,58322,58387,58453,58518,58583,58648,58713, + 58778,58843,58908,58972,59037,59101,59165,59230, + 59294,59358,59422,59486,59549,59613,59677,59740, + 59804,59867,59930,59993,60056,60119,60182,60245, + 60308,60370,60433,60495,60558,60620,60682,60744, + 60806,60868,60930,60992,61054,61115,61177,61238, + 61300,61361,61422,61483,61544,61605,61666,61727, + 61788,61848,61909,61969,62030,62090,62150,62211, + 62271,62331,62391,62450,62510,62570,62630,62689, + 62749,62808,62867,62927,62986,63045,63104,63163, + 63222,63281,63340,63398,63457,63515,63574,63632, + 63691,63749,63807,63865,63923,63981,64039,64097, + 64155,64212,64270,64328,64385,64443,64500,64557, + 64614,64672,64729,64786,64843,64900,64956,65013, + 65070,65126,65183,65239,65296,65352,65409,65465 +}; + +const png_byte png_sRGB_delta[512] = +{ + 207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54, + 52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36, + 35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28, + 28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24, + 23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21, + 21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19, + 19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17, + 17,17,17,17,17,17,16,16,16,16,16,16,16,16,16,16, + 16,16,16,16,15,15,15,15,15,15,15,15,15,15,15,15, + 15,15,15,15,14,14,14,14,14,14,14,14,14,14,14,14, + 14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13, + 13,13,13,13,13,13,13,13,13,13,13,13,13,13,12,12, + 12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12, + 12,12,12,12,12,12,12,12,12,12,12,12,11,11,11,11, + 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11, + 11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11, + 11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, + 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, + 10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10, + 10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, + 9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 +}; +#endif /* SIMPLIFIED READ/WRITE sRGB support */ + +/* SIMPLIFIED READ/WRITE SUPPORT */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +static int +png_image_free_function(png_voidp argument) +{ + png_imagep image = png_voidcast(png_imagep, argument); + png_controlp cp = image->opaque; + png_control c; + + /* Double check that we have a png_ptr - it should be impossible to get here + * without one. + */ + if (cp->png_ptr == NULL) + return 0; + + /* First free any data held in the control structure. */ +# ifdef PNG_STDIO_SUPPORTED + if (cp->owned_file != 0) + { + FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr); + cp->owned_file = 0; + + /* Ignore errors here. */ + if (fp != NULL) + { + cp->png_ptr->io_ptr = NULL; + (void)fclose(fp); + } + } +# endif + + /* Copy the control structure so that the original, allocated, version can be + * safely freed. Notice that a png_error here stops the remainder of the + * cleanup, but this is probably fine because that would indicate bad memory + * problems anyway. + */ + c = *cp; + image->opaque = &c; + png_free(c.png_ptr, cp); + + /* Then the structures, calling the correct API. */ + if (c.for_write != 0) + { +# ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED + png_destroy_write_struct(&c.png_ptr, &c.info_ptr); +# else + png_error(c.png_ptr, "simplified write not supported"); +# endif + } + else + { +# ifdef PNG_SIMPLIFIED_READ_SUPPORTED + png_destroy_read_struct(&c.png_ptr, &c.info_ptr, NULL); +# else + png_error(c.png_ptr, "simplified read not supported"); +# endif + } + + /* Success. */ + return 1; +} + +void PNGAPI +png_image_free(png_imagep image) +{ + /* Safely call the real function, but only if doing so is safe at this point + * (if not inside an error handling context). Otherwise assume + * png_safe_execute will call this API after the return. + */ + if (image != NULL && image->opaque != NULL && + image->opaque->error_buf == NULL) + { + /* Ignore errors here: */ + (void)png_safe_execute(image, png_image_free_function, image); + image->opaque = NULL; + } +} + +int /* PRIVATE */ +png_image_error(png_imagep image, png_const_charp error_message) +{ + /* Utility to log an error. */ + png_safecat(image->message, (sizeof image->message), 0, error_message); + image->warning_or_error |= PNG_IMAGE_ERROR; + png_image_free(image); + return 0; +} + +#endif /* SIMPLIFIED READ/WRITE */ +#endif /* READ || WRITE */ diff --git a/thirdparty/libpng/png.h b/thirdparty/libpng/png.h new file mode 100644 index 0000000000..1efb0b02a9 --- /dev/null +++ b/thirdparty/libpng/png.h @@ -0,0 +1,3257 @@ + +/* png.h - header file for PNG reference library + * + * libpng version 1.6.23, June 9, 2016 + * + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license (See LICENSE, below) + * + * Authors and maintainers: + * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat + * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger + * libpng versions 0.97, January 1998, through 1.6.23, June 9, 2016: + * Glenn Randers-Pehrson. + * See also "Contributing Authors", below. + */ + +/* + * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: + * + * If you modify libpng you may insert additional notices immediately following + * this sentence. + * + * This code is released under the libpng license. + * + * Some files in the "contrib" directory and some configure-generated + * files that are distributed with libpng have other copyright owners and + * are released under other open source licenses. + * + * libpng versions 1.0.7, July 1, 2000 through 1.6.23, June 9, 2016 are + * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are + * derived from libpng-1.0.6, and are distributed according to the same + * disclaimer and license as libpng-1.0.6 with the following individuals + * added to the list of Contributing Authors: + * + * Simon-Pierre Cadieux + * Eric S. Raymond + * Mans Rullgard + * Cosmin Truta + * Gilles Vollant + * James Yu + * + * and with the following additions to the disclaimer: + * + * There is no warranty against interference with your enjoyment of the + * library or against infringement. There is no warranty that our + * efforts or the library will fulfill any of your particular purposes + * or needs. This library is provided with all faults, and the entire + * risk of satisfactory quality, performance, accuracy, and effort is with + * the user. + * + * Some files in the "contrib" directory have other copyright owners and + * are released under other open source licenses. + * + * + * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are + * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from + * libpng-0.96, and are distributed according to the same disclaimer and + * license as libpng-0.96, with the following individuals added to the list + * of Contributing Authors: + * + * Tom Lane + * Glenn Randers-Pehrson + * Willem van Schaik + * + * Some files in the "scripts" directory have different copyright owners + * but are also released under this license. + * + * libpng versions 0.89, June 1996, through 0.96, May 1997, are + * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, + * and are distributed according to the same disclaimer and license as + * libpng-0.88, with the following individuals added to the list of + * Contributing Authors: + * + * John Bowler + * Kevin Bracey + * Sam Bushell + * Magnus Holmgren + * Greg Roelofs + * Tom Tanner + * + * Some files in the "scripts" directory have other copyright owners + * but are released under this license. + * + * libpng versions 0.5, May 1995, through 0.88, January 1996, are + * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. + * + * For the purposes of this copyright and license, "Contributing Authors" + * is defined as the following set of individuals: + * + * Andreas Dilger + * Dave Martindale + * Guy Eric Schalnat + * Paul Schmidt + * Tim Wegner + * + * The PNG Reference Library is supplied "AS IS". The Contributing Authors + * and Group 42, Inc. disclaim all warranties, expressed or implied, + * including, without limitation, the warranties of merchantability and of + * fitness for any purpose. The Contributing Authors and Group 42, Inc. + * assume no liability for direct, indirect, incidental, special, exemplary, + * or consequential damages, which may result from the use of the PNG + * Reference Library, even if advised of the possibility of such damage. + * + * Permission is hereby granted to use, copy, modify, and distribute this + * source code, or portions hereof, for any purpose, without fee, subject + * to the following restrictions: + * + * 1. The origin of this source code must not be misrepresented. + * + * 2. Altered versions must be plainly marked as such and must not + * be misrepresented as being the original source. + * + * 3. This Copyright notice may not be removed or altered from any + * source or altered source distribution. + * + * The Contributing Authors and Group 42, Inc. specifically permit, without + * fee, and encourage the use of this source code as a component to + * supporting the PNG file format in commercial products. If you use this + * source code in a product, acknowledgment is not required but would be + * appreciated. + * + * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. + * + * TRADEMARK: + * + * The name "libpng" has not been registered by the Copyright owner + * as a trademark in any jurisdiction. However, because libpng has + * been distributed and maintained world-wide, continually since 1995, + * the Copyright owner claims "common-law trademark protection" in any + * jurisdiction where common-law trademark is recognized. + * + * OSI CERTIFICATION: + * + * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is + * a certification mark of the Open Source Initiative. OSI has not addressed + * the additional disclaimers inserted at version 1.0.7. + * + * EXPORT CONTROL: + * + * The Copyright owner believes that the Export Control Classification + * Number (ECCN) for libpng is EAR99, which means not subject to export + * controls or International Traffic in Arms Regulations (ITAR) because + * it is open source, publicly available software, that does not contain + * any encryption software. See the EAR, paragraphs 734.3(b)(3) and + * 734.7(b). + */ + +/* + * A "png_get_copyright" function is available, for convenient use in "about" + * boxes and the like: + * + * printf("%s", png_get_copyright(NULL)); + * + * Also, the PNG logo (in PNG format, of course) is supplied in the + * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). + */ + +/* + * The contributing authors would like to thank all those who helped + * with testing, bug fixes, and patience. This wouldn't have been + * possible without all of you. + * + * Thanks to Frank J. T. Wojcik for helping with the documentation. + */ + +/* Note about libpng version numbers: + * + * Due to various miscommunications, unforeseen code incompatibilities + * and occasional factors outside the authors' control, version numbering + * on the library has not always been consistent and straightforward. + * The following table summarizes matters since version 0.89c, which was + * the first widely used release: + * + * source png.h png.h shared-lib + * version string int version + * ------- ------ ----- ---------- + * 0.89c "1.0 beta 3" 0.89 89 1.0.89 + * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] + * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] + * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] + * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] + * 0.97c 0.97 97 2.0.97 + * 0.98 0.98 98 2.0.98 + * 0.99 0.99 98 2.0.99 + * 0.99a-m 0.99 99 2.0.99 + * 1.00 1.00 100 2.1.0 [100 should be 10000] + * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] + * 1.0.1 png.h string is 10001 2.1.0 + * 1.0.1a-e identical to the 10002 from here on, the shared library + * 1.0.2 source version) 10002 is 2.V where V is the source code + * 1.0.2a-b 10003 version, except as noted. + * 1.0.3 10003 + * 1.0.3a-d 10004 + * 1.0.4 10004 + * 1.0.4a-f 10005 + * 1.0.5 (+ 2 patches) 10005 + * 1.0.5a-d 10006 + * 1.0.5e-r 10100 (not source compatible) + * 1.0.5s-v 10006 (not binary compatible) + * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) + * 1.0.6d-f 10007 (still binary incompatible) + * 1.0.6g 10007 + * 1.0.6h 10007 10.6h (testing xy.z so-numbering) + * 1.0.6i 10007 10.6i + * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) + * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) + * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) + * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) + * 1.0.7 1 10007 (still compatible) + * ... + * 1.0.19 10 10019 10.so.0.19[.0] + * ... + * 1.2.56 13 10256 12.so.0.56[.0] + * ... + * 1.5.27 15 10527 15.so.15.27[.0] + * ... + * 1.6.23 16 10623 16.so.16.23[.0] + * + * Henceforth the source version will match the shared-library major + * and minor numbers; the shared-library major version number will be + * used for changes in backward compatibility, as it is intended. The + * PNG_LIBPNG_VER macro, which is not used within libpng but is available + * for applications, is an unsigned integer of the form xyyzz corresponding + * to the source version x.y.z (leading zeros in y and z). Beta versions + * were given the previous public release number plus a letter, until + * version 1.0.6j; from then on they were given the upcoming public + * release number plus "betaNN" or "rcNN". + * + * Binary incompatibility exists only when applications make direct access + * to the info_ptr or png_ptr members through png.h, and the compiled + * application is loaded with a different version of the library. + * + * DLLNUM will change each time there are forward or backward changes + * in binary compatibility (e.g., when a new feature is added). + * + * See libpng.txt or libpng.3 for more information. The PNG specification + * is available as a W3C Recommendation and as an ISO Specification, + * <http://www.w3.org/TR/2003/REC-PNG-20031110/ + */ + +/* + * Y2K compliance in libpng: + * ========================= + * + * June 9, 2016 + * + * Since the PNG Development group is an ad-hoc body, we can't make + * an official declaration. + * + * This is your unofficial assurance that libpng from version 0.71 and + * upward through 1.6.23 are Y2K compliant. It is my belief that + * earlier versions were also Y2K compliant. + * + * Libpng only has two year fields. One is a 2-byte unsigned integer + * that will hold years up to 65535. The other, which is deprecated, + * holds the date in text format, and will hold years up to 9999. + * + * The integer is + * "png_uint_16 year" in png_time_struct. + * + * The string is + * "char time_buffer[29]" in png_struct. This is no longer used + * in libpng-1.6.x and will be removed from libpng-1.7.0. + * + * There are seven time-related functions: + * png.c: png_convert_to_rfc_1123_buffer() in png.c + * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and + * png_convert_to_rfc_1152() in error prior to libpng-0.98) + * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c + * png_convert_from_time_t() in pngwrite.c + * png_get_tIME() in pngget.c + * png_handle_tIME() in pngrutil.c, called in pngread.c + * png_set_tIME() in pngset.c + * png_write_tIME() in pngwutil.c, called in pngwrite.c + * + * All handle dates properly in a Y2K environment. The + * png_convert_from_time_t() function calls gmtime() to convert from system + * clock time, which returns (year - 1900), which we properly convert to + * the full 4-digit year. There is a possibility that libpng applications + * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer() + * function, or that they are incorrectly passing only a 2-digit year + * instead of "year - 1900" into the png_convert_from_struct_tm() function, + * but this is not under our control. The libpng documentation has always + * stated that it works with 4-digit years, and the APIs have been + * documented as such. + * + * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned + * integer to hold the year, and can hold years as large as 65535. + * + * zlib, upon which libpng depends, is also Y2K compliant. It contains + * no date-related code. + * + * Glenn Randers-Pehrson + * libpng maintainer + * PNG Development Group + */ + +#ifndef PNG_H +#define PNG_H + +/* This is not the place to learn how to use libpng. The file libpng-manual.txt + * describes how to use libpng, and the file example.c summarizes it + * with some code on which to build. This file is useful for looking + * at the actual function definitions and structure components. If that + * file has been stripped from your copy of libpng, you can find it at + * <http://www.libpng.org/pub/png/libpng-manual.txt> + * + * If you just need to read a PNG file and don't want to read the documentation + * skip to the end of this file and read the section entitled 'simplified API'. + */ + +/* Version information for png.h - this should match the version in png.c */ +#define PNG_LIBPNG_VER_STRING "1.6.23" +#define PNG_HEADER_VERSION_STRING \ + " libpng version 1.6.23 - June 9, 2016\n" + +#define PNG_LIBPNG_VER_SONUM 16 +#define PNG_LIBPNG_VER_DLLNUM 16 + +/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ +#define PNG_LIBPNG_VER_MAJOR 1 +#define PNG_LIBPNG_VER_MINOR 6 +#define PNG_LIBPNG_VER_RELEASE 23 + +/* This should match the numeric part of the final component of + * PNG_LIBPNG_VER_STRING, omitting any leading zero: + */ + +#define PNG_LIBPNG_VER_BUILD 0 + +/* Release Status */ +#define PNG_LIBPNG_BUILD_ALPHA 1 +#define PNG_LIBPNG_BUILD_BETA 2 +#define PNG_LIBPNG_BUILD_RC 3 +#define PNG_LIBPNG_BUILD_STABLE 4 +#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 + +/* Release-Specific Flags */ +#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with + PNG_LIBPNG_BUILD_STABLE only */ +#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_SPECIAL */ +#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_PRIVATE */ + +#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE + +/* Careful here. At one time, Guy wanted to use 082, but that would be octal. + * We must not include leading zeros. + * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only + * version 1.0.0 was mis-numbered 100 instead of 10000). From + * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release + */ +#define PNG_LIBPNG_VER 10623 /* 1.6.23 */ + +/* Library configuration: these options cannot be changed after + * the library has been built. + */ +#ifndef PNGLCONF_H + /* If pnglibconf.h is missing, you can + * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h + */ +# include "pnglibconf.h" +#endif + +#ifndef PNG_VERSION_INFO_ONLY + /* Machine specific configuration. */ +# include "pngconf.h" +#endif + +/* + * Added at libpng-1.2.8 + * + * Ref MSDN: Private as priority over Special + * VS_FF_PRIVATEBUILD File *was not* built using standard release + * procedures. If this value is given, the StringFileInfo block must + * contain a PrivateBuild string. + * + * VS_FF_SPECIALBUILD File *was* built by the original company using + * standard release procedures but is a variation of the standard + * file of the same version number. If this value is given, the + * StringFileInfo block must contain a SpecialBuild string. + */ + +#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) +#else +# ifdef PNG_LIBPNG_SPECIALBUILD +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) +# else +# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) +# endif +#endif + +#ifndef PNG_VERSION_INFO_ONLY + +/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Version information for C files, stored in png.c. This had better match + * the version above. + */ +#define png_libpng_ver png_get_header_ver(NULL) + +/* This file is arranged in several sections: + * + * 1. [omitted] + * 2. Any configuration options that can be specified by for the application + * code when it is built. (Build time configuration is in pnglibconf.h) + * 3. Type definitions (base types are defined in pngconf.h), structure + * definitions. + * 4. Exported library functions. + * 5. Simplified API. + * 6. Implementation options. + * + * The library source code has additional files (principally pngpriv.h) that + * allow configuration of the library. + */ + +/* Section 1: [omitted] */ + +/* Section 2: run time configuration + * See pnglibconf.h for build time configuration + * + * Run time configuration allows the application to choose between + * implementations of certain arithmetic APIs. The default is set + * at build time and recorded in pnglibconf.h, but it is safe to + * override these (and only these) settings. Note that this won't + * change what the library does, only application code, and the + * settings can (and probably should) be made on a per-file basis + * by setting the #defines before including png.h + * + * Use macros to read integers from PNG data or use the exported + * functions? + * PNG_USE_READ_MACROS: use the macros (see below) Note that + * the macros evaluate their argument multiple times. + * PNG_NO_USE_READ_MACROS: call the relevant library function. + * + * Use the alternative algorithm for compositing alpha samples that + * does not use division? + * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' + * algorithm. + * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. + * + * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is + * false? + * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error + * APIs to png_warning. + * Otherwise the calls are mapped to png_error. + */ + +/* Section 3: type definitions, including structures and compile time + * constants. + * See pngconf.h for base types that vary by machine/system + */ + +/* This triggers a compiler error in png.c, if png.c and png.h + * do not agree upon the version number. + */ +typedef char* png_libpng_version_1_6_23; + +/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info. + * + * png_struct is the cache of information used while reading or writing a single + * PNG file. One of these is always required, although the simplified API + * (below) hides the creation and destruction of it. + */ +typedef struct png_struct_def png_struct; +typedef const png_struct * png_const_structp; +typedef png_struct * png_structp; +typedef png_struct * * png_structpp; + +/* png_info contains information read from or to be written to a PNG file. One + * or more of these must exist while reading or creating a PNG file. The + * information is not used by libpng during read but is used to control what + * gets written when a PNG file is created. "png_get_" function calls read + * information during read and "png_set_" functions calls write information + * when creating a PNG. + * been moved into a separate header file that is not accessible to + * applications. Read libpng-manual.txt or libpng.3 for more info. + */ +typedef struct png_info_def png_info; +typedef png_info * png_infop; +typedef const png_info * png_const_infop; +typedef png_info * * png_infopp; + +/* Types with names ending 'p' are pointer types. The corresponding types with + * names ending 'rp' are identical pointer types except that the pointer is + * marked 'restrict', which means that it is the only pointer to the object + * passed to the function. Applications should not use the 'restrict' types; + * it is always valid to pass 'p' to a pointer with a function argument of the + * corresponding 'rp' type. Different compilers have different rules with + * regard to type matching in the presence of 'restrict'. For backward + * compatibility libpng callbacks never have 'restrict' in their parameters and, + * consequentially, writing portable application code is extremely difficult if + * an attempt is made to use 'restrict'. + */ +typedef png_struct * PNG_RESTRICT png_structrp; +typedef const png_struct * PNG_RESTRICT png_const_structrp; +typedef png_info * PNG_RESTRICT png_inforp; +typedef const png_info * PNG_RESTRICT png_const_inforp; + +/* Three color definitions. The order of the red, green, and blue, (and the + * exact size) is not important, although the size of the fields need to + * be png_byte or png_uint_16 (as defined below). + */ +typedef struct png_color_struct +{ + png_byte red; + png_byte green; + png_byte blue; +} png_color; +typedef png_color * png_colorp; +typedef const png_color * png_const_colorp; +typedef png_color * * png_colorpp; + +typedef struct png_color_16_struct +{ + png_byte index; /* used for palette files */ + png_uint_16 red; /* for use in red green blue files */ + png_uint_16 green; + png_uint_16 blue; + png_uint_16 gray; /* for use in grayscale files */ +} png_color_16; +typedef png_color_16 * png_color_16p; +typedef const png_color_16 * png_const_color_16p; +typedef png_color_16 * * png_color_16pp; + +typedef struct png_color_8_struct +{ + png_byte red; /* for use in red green blue files */ + png_byte green; + png_byte blue; + png_byte gray; /* for use in grayscale files */ + png_byte alpha; /* for alpha channel files */ +} png_color_8; +typedef png_color_8 * png_color_8p; +typedef const png_color_8 * png_const_color_8p; +typedef png_color_8 * * png_color_8pp; + +/* + * The following two structures are used for the in-core representation + * of sPLT chunks. + */ +typedef struct png_sPLT_entry_struct +{ + png_uint_16 red; + png_uint_16 green; + png_uint_16 blue; + png_uint_16 alpha; + png_uint_16 frequency; +} png_sPLT_entry; +typedef png_sPLT_entry * png_sPLT_entryp; +typedef const png_sPLT_entry * png_const_sPLT_entryp; +typedef png_sPLT_entry * * png_sPLT_entrypp; + +/* When the depth of the sPLT palette is 8 bits, the color and alpha samples + * occupy the LSB of their respective members, and the MSB of each member + * is zero-filled. The frequency member always occupies the full 16 bits. + */ + +typedef struct png_sPLT_struct +{ + png_charp name; /* palette name */ + png_byte depth; /* depth of palette samples */ + png_sPLT_entryp entries; /* palette entries */ + png_int_32 nentries; /* number of palette entries */ +} png_sPLT_t; +typedef png_sPLT_t * png_sPLT_tp; +typedef const png_sPLT_t * png_const_sPLT_tp; +typedef png_sPLT_t * * png_sPLT_tpp; + +#ifdef PNG_TEXT_SUPPORTED +/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, + * and whether that contents is compressed or not. The "key" field + * points to a regular zero-terminated C string. The "text" fields can be a + * regular C string, an empty string, or a NULL pointer. + * However, the structure returned by png_get_text() will always contain + * the "text" field as a regular zero-terminated C string (possibly + * empty), never a NULL pointer, so it can be safely used in printf() and + * other string-handling functions. Note that the "itxt_length", "lang", and + * "lang_key" members of the structure only exist when the library is built + * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by + * default without iTXt support. Also note that when iTXt *is* supported, + * the "lang" and "lang_key" fields contain NULL pointers when the + * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or + * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the + * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag" + * which is always 0 or 1, or its "compression method" which is always 0. + */ +typedef struct png_text_struct +{ + int compression; /* compression value: + -1: tEXt, none + 0: zTXt, deflate + 1: iTXt, none + 2: iTXt, deflate */ + png_charp key; /* keyword, 1-79 character description of "text" */ + png_charp text; /* comment, may be an empty string (ie "") + or a NULL pointer */ + png_size_t text_length; /* length of the text string */ + png_size_t itxt_length; /* length of the itxt string */ + png_charp lang; /* language code, 0-79 characters + or a NULL pointer */ + png_charp lang_key; /* keyword translated UTF-8 string, 0 or more + chars or a NULL pointer */ +} png_text; +typedef png_text * png_textp; +typedef const png_text * png_const_textp; +typedef png_text * * png_textpp; +#endif + +/* Supported compression types for text in PNG files (tEXt, and zTXt). + * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ +#define PNG_TEXT_COMPRESSION_NONE_WR -3 +#define PNG_TEXT_COMPRESSION_zTXt_WR -2 +#define PNG_TEXT_COMPRESSION_NONE -1 +#define PNG_TEXT_COMPRESSION_zTXt 0 +#define PNG_ITXT_COMPRESSION_NONE 1 +#define PNG_ITXT_COMPRESSION_zTXt 2 +#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ + +/* png_time is a way to hold the time in an machine independent way. + * Two conversions are provided, both from time_t and struct tm. There + * is no portable way to convert to either of these structures, as far + * as I know. If you know of a portable way, send it to me. As a side + * note - PNG has always been Year 2000 compliant! + */ +typedef struct png_time_struct +{ + png_uint_16 year; /* full year, as in, 1995 */ + png_byte month; /* month of year, 1 - 12 */ + png_byte day; /* day of month, 1 - 31 */ + png_byte hour; /* hour of day, 0 - 23 */ + png_byte minute; /* minute of hour, 0 - 59 */ + png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ +} png_time; +typedef png_time * png_timep; +typedef const png_time * png_const_timep; +typedef png_time * * png_timepp; + +#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\ + defined(PNG_USER_CHUNKS_SUPPORTED) +/* png_unknown_chunk is a structure to hold queued chunks for which there is + * no specific support. The idea is that we can use this to queue + * up private chunks for output even though the library doesn't actually + * know about their semantics. + * + * The data in the structure is set by libpng on read and used on write. + */ +typedef struct png_unknown_chunk_t +{ + png_byte name[5]; /* Textual chunk name with '\0' terminator */ + png_byte *data; /* Data, should not be modified on read! */ + png_size_t size; + + /* On write 'location' must be set using the flag values listed below. + * Notice that on read it is set by libpng however the values stored have + * more bits set than are listed below. Always treat the value as a + * bitmask. On write set only one bit - setting multiple bits may cause the + * chunk to be written in multiple places. + */ + png_byte location; /* mode of operation at read time */ +} +png_unknown_chunk; + +typedef png_unknown_chunk * png_unknown_chunkp; +typedef const png_unknown_chunk * png_const_unknown_chunkp; +typedef png_unknown_chunk * * png_unknown_chunkpp; +#endif + +/* Flag values for the unknown chunk location byte. */ +#define PNG_HAVE_IHDR 0x01 +#define PNG_HAVE_PLTE 0x02 +#define PNG_AFTER_IDAT 0x08 + +/* Maximum positive integer used in PNG is (2^31)-1 */ +#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) +#define PNG_UINT_32_MAX ((png_uint_32)(-1)) +#define PNG_SIZE_MAX ((png_size_t)(-1)) + +/* These are constants for fixed point values encoded in the + * PNG specification manner (x100000) + */ +#define PNG_FP_1 100000 +#define PNG_FP_HALF 50000 +#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL) +#define PNG_FP_MIN (-PNG_FP_MAX) + +/* These describe the color_type field in png_info. */ +/* color type masks */ +#define PNG_COLOR_MASK_PALETTE 1 +#define PNG_COLOR_MASK_COLOR 2 +#define PNG_COLOR_MASK_ALPHA 4 + +/* color types. Note that not all combinations are legal */ +#define PNG_COLOR_TYPE_GRAY 0 +#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) +#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) +#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) +#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) +/* aliases */ +#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA +#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA + +/* This is for compression type. PNG 1.0-1.2 only define the single type. */ +#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ +#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE + +/* This is for filter type. PNG 1.0-1.2 only define the single type. */ +#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ +#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ +#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE + +/* These are for the interlacing type. These values should NOT be changed. */ +#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ +#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ +#define PNG_INTERLACE_LAST 2 /* Not a valid value */ + +/* These are for the oFFs chunk. These values should NOT be changed. */ +#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ +#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ +#define PNG_OFFSET_LAST 2 /* Not a valid value */ + +/* These are for the pCAL chunk. These values should NOT be changed. */ +#define PNG_EQUATION_LINEAR 0 /* Linear transformation */ +#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ +#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ +#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ +#define PNG_EQUATION_LAST 4 /* Not a valid value */ + +/* These are for the sCAL chunk. These values should NOT be changed. */ +#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ +#define PNG_SCALE_METER 1 /* meters per pixel */ +#define PNG_SCALE_RADIAN 2 /* radians per pixel */ +#define PNG_SCALE_LAST 3 /* Not a valid value */ + +/* These are for the pHYs chunk. These values should NOT be changed. */ +#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ +#define PNG_RESOLUTION_METER 1 /* pixels/meter */ +#define PNG_RESOLUTION_LAST 2 /* Not a valid value */ + +/* These are for the sRGB chunk. These values should NOT be changed. */ +#define PNG_sRGB_INTENT_PERCEPTUAL 0 +#define PNG_sRGB_INTENT_RELATIVE 1 +#define PNG_sRGB_INTENT_SATURATION 2 +#define PNG_sRGB_INTENT_ABSOLUTE 3 +#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ + +/* This is for text chunks */ +#define PNG_KEYWORD_MAX_LENGTH 79 + +/* Maximum number of entries in PLTE/sPLT/tRNS arrays */ +#define PNG_MAX_PALETTE_LENGTH 256 + +/* These determine if an ancillary chunk's data has been successfully read + * from the PNG header, or if the application has filled in the corresponding + * data in the info_struct to be written into the output file. The values + * of the PNG_INFO_<chunk> defines should NOT be changed. + */ +#define PNG_INFO_gAMA 0x0001U +#define PNG_INFO_sBIT 0x0002U +#define PNG_INFO_cHRM 0x0004U +#define PNG_INFO_PLTE 0x0008U +#define PNG_INFO_tRNS 0x0010U +#define PNG_INFO_bKGD 0x0020U +#define PNG_INFO_hIST 0x0040U +#define PNG_INFO_pHYs 0x0080U +#define PNG_INFO_oFFs 0x0100U +#define PNG_INFO_tIME 0x0200U +#define PNG_INFO_pCAL 0x0400U +#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */ +#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */ +#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */ +#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */ +#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */ + +/* This is used for the transformation routines, as some of them + * change these values for the row. It also should enable using + * the routines for other purposes. + */ +typedef struct png_row_info_struct +{ + png_uint_32 width; /* width of row */ + png_size_t rowbytes; /* number of bytes in row */ + png_byte color_type; /* color type of row */ + png_byte bit_depth; /* bit depth of row */ + png_byte channels; /* number of channels (1, 2, 3, or 4) */ + png_byte pixel_depth; /* bits per pixel (depth * channels) */ +} png_row_info; + +typedef png_row_info * png_row_infop; +typedef png_row_info * * png_row_infopp; + +/* These are the function types for the I/O functions and for the functions + * that allow the user to override the default I/O functions with his or her + * own. The png_error_ptr type should match that of user-supplied warning + * and error functions, while the png_rw_ptr type should match that of the + * user read/write data functions. Note that the 'write' function must not + * modify the buffer it is passed. The 'read' function, on the other hand, is + * expected to return the read data in the buffer. + */ +typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp)); +typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t)); +typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp)); +typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, + int)); +typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, + int)); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop)); +typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop)); + +/* The following callback receives png_uint_32 row_number, int pass for the + * png_bytep data of the row. When transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) + */ +typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep, + png_uint_32, int)); +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop, + png_bytep)); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, + png_unknown_chunkp)); +#endif +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED +/* not used anywhere */ +/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */ +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* This must match the function definition in <setjmp.h>, and the application + * must include this before png.h to obtain the definition of jmp_buf. The + * function is required to be PNG_NORETURN, but this is not checked. If the + * function does return the application will crash via an abort() or similar + * system level call. + * + * If you get a warning here while building the library you may need to make + * changes to ensure that pnglibconf.h records the calling convention used by + * your compiler. This may be very difficult - try using a different compiler + * to build the library! + */ +PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef); +#endif + +/* Transform masks for the high-level interface */ +#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ +#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ +#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ +#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ +#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ +#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ +#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ +#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ +#define PNG_TRANSFORM_BGR 0x0080 /* read and write */ +#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ +#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ +#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ +#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ +/* Added to libpng-1.2.34 */ +#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER +#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ +/* Added to libpng-1.4.0 */ +#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ +/* Added to libpng-1.5.4 */ +#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */ +#if INT_MAX >= 0x8000 /* else this might break */ +#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */ +#endif + +/* Flags for MNG supported features */ +#define PNG_FLAG_MNG_EMPTY_PLTE 0x01 +#define PNG_FLAG_MNG_FILTER_64 0x04 +#define PNG_ALL_MNG_FEATURES 0x05 + +/* NOTE: prior to 1.5 these functions had no 'API' style declaration, + * this allowed the zlib default functions to be used on Windows + * platforms. In 1.5 the zlib default malloc (which just calls malloc and + * ignores the first argument) should be completely compatible with the + * following. + */ +typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, + png_alloc_size_t)); +typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp)); + +/* Section 4: exported functions + * Here are the function definitions most commonly used. This is not + * the place to find out how to use libpng. See libpng-manual.txt for the + * full explanation, see example.c for the summary. This just provides + * a simple one line description of the use of each function. + * + * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in + * pngconf.h and in the *.dfn files in the scripts directory. + * + * PNG_EXPORT(ordinal, type, name, (args)); + * + * ordinal: ordinal that is used while building + * *.def files. The ordinal value is only + * relevant when preprocessing png.h with + * the *.dfn files for building symbol table + * entries, and are removed by pngconf.h. + * type: return type of the function + * name: function name + * args: function arguments, with types + * + * When we wish to append attributes to a function prototype we use + * the PNG_EXPORTA() macro instead. + * + * PNG_EXPORTA(ordinal, type, name, (args), attributes); + * + * ordinal, type, name, and args: same as in PNG_EXPORT(). + * attributes: function attributes + */ + +/* Returns the version number of the library */ +PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); + +/* Tell lib we have already handled the first <num_bytes> magic bytes. + * Handling more than 8 bytes from the beginning of the file is an error. + */ +PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes)); + +/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a + * PNG file. Returns zero if the supplied bytes match the 8-byte PNG + * signature, and non-zero otherwise. Having num_to_check == 0 or + * start > 7 will always fail (ie return non-zero). + */ +PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, + png_size_t num_to_check)); + +/* Simple signature checking function. This is the same as calling + * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). + */ +#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) + +/* Allocate and initialize png_ptr struct for reading, and any other memory. */ +PNG_EXPORTA(4, png_structp, png_create_read_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn), + PNG_ALLOCATED); + +/* Allocate and initialize png_ptr struct for writing, and any other memory */ +PNG_EXPORTA(5, png_structp, png_create_write_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn), + PNG_ALLOCATED); + +PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, + (png_const_structrp png_ptr)); + +PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr, + png_size_t size)); + +/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp + * match up. + */ +#ifdef PNG_SETJMP_SUPPORTED +/* This function returns the jmp_buf built in to *png_ptr. It must be + * supplied with an appropriate 'longjmp' function to use on that jmp_buf + * unless the default error function is overridden in which case NULL is + * acceptable. The size of the jmp_buf is checked against the actual size + * allocated by the library - the call will return NULL on a mismatch + * indicating an ABI mismatch. + */ +PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr, + png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); +# define png_jmpbuf(png_ptr) \ + (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf)))) +#else +# define png_jmpbuf(png_ptr) \ + (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) +#endif +/* This function should be used by libpng applications in place of + * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it + * will use it; otherwise it will call PNG_ABORT(). This function was + * added in libpng-1.5.0. + */ +PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val), + PNG_NORETURN); + +#ifdef PNG_READ_SUPPORTED +/* Reset the compression stream */ +PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED); +#endif + +/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(11, png_structp, png_create_read_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +PNG_EXPORTA(12, png_structp, png_create_write_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +#endif + +/* Write the PNG file signature. */ +PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr)); + +/* Write a PNG chunk - size, type, (optional) data, CRC. */ +PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep + chunk_name, png_const_bytep data, png_size_t length)); + +/* Write the start of a PNG chunk - length and chunk name. */ +PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr, + png_const_bytep chunk_name, png_uint_32 length)); + +/* Write the data of a PNG chunk started with png_write_chunk_start(). */ +PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr, + png_const_bytep data, png_size_t length)); + +/* Finish a chunk started with png_write_chunk_start() (includes CRC). */ +PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr)); + +/* Allocate and initialize the info structure */ +PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr), + PNG_ALLOCATED); + +/* DEPRECATED: this function allowed init structures to be created using the + * default allocation method (typically malloc). Use is deprecated in 1.6.0 and + * the API will be removed in the future. + */ +PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr, + png_size_t png_info_struct_size), PNG_DEPRECATED); + +/* Writes all the PNG information before the image. */ +PNG_EXPORT(20, void, png_write_info_before_PLTE, + (png_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(21, void, png_write_info, + (png_structrp png_ptr, png_const_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the information before the actual image data. */ +PNG_EXPORT(22, void, png_read_info, + (png_structrp png_ptr, png_inforp info_ptr)); +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED + /* Convert to a US string format: there is no localization support in this + * routine. The original implementation used a 29 character buffer in + * png_struct, this will be removed in future versions. + */ +#if PNG_LIBPNG_VER < 10700 +/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */ +PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr, + png_const_timep ptime),PNG_DEPRECATED); +#endif +PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29], + png_const_timep ptime)); +#endif + +#ifdef PNG_CONVERT_tIME_SUPPORTED +/* Convert from a struct tm to png_time */ +PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, + const struct tm * ttime)); + +/* Convert from time_t to png_time. Uses gmtime() */ +PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime)); +#endif /* CONVERT_tIME */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ +PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr)); +PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr)); +PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr)); +PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion + * of a tRNS chunk if present. + */ +PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Use blue, green, red order for pixels. */ +PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* Expand the grayscale to 24-bit RGB if necessary. */ +PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* Reduce RGB to grayscale. */ +#define PNG_ERROR_ACTION_NONE 1 +#define PNG_ERROR_ACTION_WARN 2 +#define PNG_ERROR_ACTION_ERROR 3 +#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/ + +PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr, + int error_action, double red, double green)) +PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr, + int error_action, png_fixed_point red, png_fixed_point green)) + +PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp + png_ptr)); +#endif + +#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, + png_colorp palette)); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +/* How the alpha channel is interpreted - this affects how the color channels + * of a PNG file are returned to the calling application when an alpha channel, + * or a tRNS chunk in a palette file, is present. + * + * This has no effect on the way pixels are written into a PNG output + * datastream. The color samples in a PNG datastream are never premultiplied + * with the alpha samples. + * + * The default is to return data according to the PNG specification: the alpha + * channel is a linear measure of the contribution of the pixel to the + * corresponding composited pixel, and the color channels are unassociated + * (not premultiplied). The gamma encoded color channels must be scaled + * according to the contribution and to do this it is necessary to undo + * the encoding, scale the color values, perform the composition and reencode + * the values. This is the 'PNG' mode. + * + * The alternative is to 'associate' the alpha with the color information by + * storing color channel values that have been scaled by the alpha. + * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes + * (the latter being the two common names for associated alpha color channels). + * + * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha + * value is equal to the maximum value. + * + * The final choice is to gamma encode the alpha channel as well. This is + * broken because, in practice, no implementation that uses this choice + * correctly undoes the encoding before handling alpha composition. Use this + * choice only if other serious errors in the software or hardware you use + * mandate it; the typical serious error is for dark halos to appear around + * opaque areas of the composited PNG image because of arithmetic overflow. + * + * The API function png_set_alpha_mode specifies which of these choices to use + * with an enumerated 'mode' value and the gamma of the required output: + */ +#define PNG_ALPHA_PNG 0 /* according to the PNG standard */ +#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */ +#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */ +#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */ +#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */ +#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */ + +PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode, + double output_gamma)) +PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr, + int mode, png_fixed_point output_gamma)) +#endif + +#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED) +/* The output_gamma value is a screen gamma in libpng terminology: it expresses + * how to decode the output values, not how they are encoded. + */ +#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */ +#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */ +#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */ +#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */ +#endif + +/* The following are examples of calls to png_set_alpha_mode to achieve the + * required overall gamma correction and, where necessary, alpha + * premultiplication. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * This is the default libpng handling of the alpha channel - it is not + * pre-multiplied into the color components. In addition the call states + * that the output is for a sRGB system and causes all PNG files without gAMA + * chunks to be assumed to be encoded using sRGB. + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * In this case the output is assumed to be something like an sRGB conformant + * display preceeded by a power-law lookup table of power 1.45. This is how + * early Mac systems behaved. + * + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); + * This is the classic Jim Blinn approach and will work in academic + * environments where everything is done by the book. It has the shortcoming + * of assuming that input PNG data with no gamma information is linear - this + * is unlikely to be correct unless the PNG files where generated locally. + * Most of the time the output precision will be so low as to show + * significant banding in dark areas of the image. + * + * png_set_expand_16(pp); + * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB); + * This is a somewhat more realistic Jim Blinn inspired approach. PNG files + * are assumed to have the sRGB encoding if not marked with a gamma value and + * the output is always 16 bits per component. This permits accurate scaling + * and processing of the data. If you know that your input PNG files were + * generated locally you might need to replace PNG_DEFAULT_sRGB with the + * correct value for your system. + * + * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB); + * If you just need to composite the PNG image onto an existing background + * and if you control the code that does this you can use the optimization + * setting. In this case you just copy completely opaque pixels to the + * output. For pixels that are not completely transparent (you just skip + * those) you do the composition math using png_composite or png_composite_16 + * below then encode the resultant 8-bit or 16-bit values to match the output + * encoding. + * + * Other cases + * If neither the PNG nor the standard linear encoding work for you because + * of the software or hardware you use then you have a big problem. The PNG + * case will probably result in halos around the image. The linear encoding + * will probably result in a washed out, too bright, image (it's actually too + * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably + * substantially reduce the halos. Alternatively try: + * + * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB); + * This option will also reduce the halos, but there will be slight dark + * halos round the opaque parts of the image where the background is light. + * In the OPTIMIZED mode the halos will be light halos where the background + * is dark. Take your pick - the halos are unavoidable unless you can get + * your hardware/software fixed! (The OPTIMIZED approach is slightly + * faster.) + * + * When the default gamma of PNG files doesn't match the output gamma. + * If you have PNG files with no gamma information png_set_alpha_mode allows + * you to provide a default gamma, but it also sets the ouput gamma to the + * matching value. If you know your PNG files have a gamma that doesn't + * match the output you can take advantage of the fact that + * png_set_alpha_mode always sets the output gamma but only sets the PNG + * default if it is not already set: + * + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB); + * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); + * The first call sets both the default and the output gamma values, the + * second call overrides the output gamma without changing the default. This + * is easier than achieving the same effect with png_set_gamma. You must use + * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will + * fire if more than one call to png_set_alpha_mode and png_set_background is + * made in the same read operation, however multiple calls with PNG_ALPHA_PNG + * are ignored. + */ + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ +PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler, + int flags)); +/* The values of the PNG_FILLER_ defines should NOT be changed */ +# define PNG_FILLER_BEFORE 0 +# define PNG_FILLER_AFTER 1 +/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */ +PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr, + png_uint_32 filler, int flags)); +#endif /* READ_FILLER || WRITE_FILLER */ + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swap bytes in 16-bit depth files. */ +PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ +PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ + defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Swap packing order of pixels in bytes. */ +PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +/* Converts files to legal bit depths. */ +PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p + true_bits)); +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +/* Have the code handle the interlacing. Returns the number of passes. + * MUST be called before png_read_update_info or png_start_read_image, + * otherwise it will not have the desired effect. Note that it is still + * necessary to call png_read_row or png_read_rows png_get_image_height + * times for each pass. +*/ +PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +/* Invert monochrome files */ +PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Handle alpha and tRNS by replacing with a background color. Prior to + * libpng-1.5.4 this API must not be called before the PNG file header has been + * read. Doing so will result in unexpected behavior and possible warnings or + * errors if the PNG file contains a bKGD chunk. + */ +PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma)) +PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, png_fixed_point background_gamma)) +#endif +#ifdef PNG_READ_BACKGROUND_SUPPORTED +# define PNG_BACKGROUND_GAMMA_UNKNOWN 0 +# define PNG_BACKGROUND_GAMMA_SCREEN 1 +# define PNG_BACKGROUND_GAMMA_FILE 2 +# define PNG_BACKGROUND_GAMMA_UNIQUE 3 +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +/* Scale a 16-bit depth file down to 8-bit, accurately. */ +PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */ +/* Strip the second byte of information from a 16-bit depth file. */ +PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr)); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* Turn on quantizing, and reduce the palette to the number of colors + * available. + */ +PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr, + png_colorp palette, int num_palette, int maximum_colors, + png_const_uint_16p histogram, int full_quantize)); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* The threshold on gamma processing is configurable but hard-wired into the + * library. The following is the floating point variant. + */ +#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) + +/* Handle gamma correction. Screen_gamma=(display_exponent). + * NOTE: this API simply sets the screen and file gamma values. It will + * therefore override the value for gamma in a PNG file if it is called after + * the file header has been read - use with care - call before reading the PNG + * file for best results! + * + * These routines accept the same gamma values as png_set_alpha_mode (described + * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either + * API (floating point or fixed.) Notice, however, that the 'file_gamma' value + * is the inverse of a 'screen gamma' value. + */ +PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr, + double screen_gamma, double override_file_gamma)) +PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr, + png_fixed_point screen_gamma, png_fixed_point override_file_gamma)) +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +/* Set how many lines between output flushes - 0 for no flushing */ +PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows)); +/* Flush the current PNG output buffer */ +PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr)); +#endif + +/* Optional update palette with requested transformations */ +PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr)); + +/* Optional call to update the users info structure */ +PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr, + png_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read one or more rows of image data. */ +PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read a row of data. */ +PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row, + png_bytep display_row)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the whole image into memory at once. */ +PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image)); +#endif + +/* Write a row of image data */ +PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr, + png_const_bytep row)); + +/* Write a few rows of image data: (*row) is not written; however, the type + * is declared as writeable to maintain compatibility with previous versions + * of libpng and to allow the 'display_row' array from read_rows to be passed + * unchanged to write_rows. + */ +PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row, + png_uint_32 num_rows)); + +/* Write the image data */ +PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image)); + +/* Write the end of the PNG file. */ +PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr, + png_inforp info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the end of the PNG file. */ +PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr)); +#endif + +/* Free any memory associated with the png_info_struct */ +PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr, + png_infopp info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr)); + +/* Set the libpng method of handling chunk CRC errors */ +PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action, + int ancil_action)); + +/* Values for png_set_crc_action() say how to handle CRC errors in + * ancillary and critical chunks, and whether to use the data contained + * therein. Note that it is impossible to "discard" data in a critical + * chunk. For versions prior to 0.90, the action was always error/quit, + * whereas in version 0.90 and later, the action for CRC errors in ancillary + * chunks is warn/discard. These values should NOT be changed. + * + * value action:critical action:ancillary + */ +#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ +#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ +#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ +#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ +#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ +#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ + +#ifdef PNG_WRITE_SUPPORTED +/* These functions give the user control over the scan-line filtering in + * libpng and the compression methods used by zlib. These functions are + * mainly useful for testing, as the defaults should work with most users. + * Those users who are tight on memory or want faster performance at the + * expense of compression can modify them. See the compression library + * header file (zlib.h) for an explination of the compression functions. + */ + +/* Set the filtering method(s) used by libpng. Currently, the only valid + * value for "method" is 0. + */ +PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method, + int filters)); +#endif /* WRITE */ + +/* Flags for png_set_filter() to say which filters to use. The flags + * are chosen so that they don't conflict with real filter types + * below, in case they are supplied instead of the #defined constants. + * These values should NOT be changed. + */ +#define PNG_NO_FILTERS 0x00 +#define PNG_FILTER_NONE 0x08 +#define PNG_FILTER_SUB 0x10 +#define PNG_FILTER_UP 0x20 +#define PNG_FILTER_AVG 0x40 +#define PNG_FILTER_PAETH 0x80 +#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP) +#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH) + +/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. + * These defines should NOT be changed. + */ +#define PNG_FILTER_VALUE_NONE 0 +#define PNG_FILTER_VALUE_SUB 1 +#define PNG_FILTER_VALUE_UP 2 +#define PNG_FILTER_VALUE_AVG 3 +#define PNG_FILTER_VALUE_PAETH 4 +#define PNG_FILTER_VALUE_LAST 5 + +#ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ +PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr, + int heuristic_method, int num_weights, png_const_doublep filter_weights, + png_const_doublep filter_costs)) +PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, + (png_structrp png_ptr, int heuristic_method, int num_weights, + png_const_fixed_point_p filter_weights, + png_const_fixed_point_p filter_costs)) +#endif /* WRITE_WEIGHTED_FILTER */ + +/* The following are no longer used and will be removed from libpng-1.7: */ +#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ +#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ +#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ +#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ + +/* Set the library compression level. Currently, valid values range from + * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 + * (0 - no compression, 9 - "maximal" compression). Note that tests have + * shown that zlib compression levels 3-6 usually perform as well as level 9 + * for PNG images, and do considerably fewer caclulations. In the future, + * these values may not correspond directly to the zlib compression levels. + */ +#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED +PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr, + int level)); + +PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr, + int mem_level)); + +PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr, + int strategy)); + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr, + int window_bits)); + +PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr, + int method)); +#endif /* WRITE_CUSTOMIZE_COMPRESSION */ + +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +/* Also set zlib parameters for compressing non-IDAT chunks */ +PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr, + int level)); + +PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr, + int mem_level)); + +PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr, + int strategy)); + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +PNG_EXPORT(225, void, png_set_text_compression_window_bits, + (png_structrp png_ptr, int window_bits)); + +PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr, + int method)); +#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ +#endif /* WRITE */ + +/* These next functions are called for input/output, memory, and error + * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, + * and call standard C I/O routines such as fread(), fwrite(), and + * fprintf(). These functions can be made to use other I/O routines + * at run time for those applications that need to handle I/O in a + * different manner by calling png_set_???_fn(). See libpng-manual.txt for + * more information. + */ + +#ifdef PNG_STDIO_SUPPORTED +/* Initialize the input/output for the PNG file to the default functions. */ +PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp)); +#endif + +/* Replace the (error and abort), and warning functions with user + * supplied functions. If no messages are to be printed you must still + * write and use replacement functions. The replacement error_fn should + * still do a longjmp to the last setjmp location if you are using this + * method of error handling. If error_fn or warning_fn is NULL, the + * default function will be used. + */ + +PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); + +/* Return the user pointer associated with the error functions */ +PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr)); + +/* Replace the default data output functions with a user supplied one(s). + * If buffered output is not used, then output_flush_fn can be set to NULL. + * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time + * output_flush_fn will be ignored (and thus can be NULL). + * It is probably a mistake to use NULL for output_flush_fn if + * write_data_fn is not also NULL unless you have built libpng with + * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's + * default flush function, which uses the standard *FILE structure, will + * be used. + */ +PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); + +/* Replace the default data input function with a user supplied one. */ +PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn)); + +/* Return the user pointer associated with the I/O functions */ +PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr)); + +PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr, + png_read_status_ptr read_row_fn)); + +PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr, + png_write_status_ptr write_row_fn)); + +#ifdef PNG_USER_MEM_SUPPORTED +/* Replace the default memory allocation functions with user supplied one(s). */ +PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn)); +/* Return the user pointer associated with the memory functions */ +PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr, + png_user_transform_ptr read_user_transform_fn)); +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr, + png_user_transform_ptr write_user_transform_fn)); +#endif + +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr, + png_voidp user_transform_ptr, int user_transform_depth, + int user_transform_channels)); +/* Return the user pointer associated with the user transform functions */ +PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, + (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED +/* Return information about the row currently being processed. Note that these + * APIs do not fail but will return unexpected results if called outside a user + * transform callback. Also note that when transforming an interlaced image the + * row number is the row number within the sub-image of the interlace pass, so + * the value will increase to the height of the sub-image (not the full image) + * then reset to 0 for the next pass. + * + * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to + * find the output pixel (x,y) given an interlaced sub-image pixel + * (row,col,pass). (See below for these macros.) + */ +PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp)); +PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp)); +#endif + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED +/* This callback is called only for *unknown* chunks. If + * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known + * chunks to be treated as unknown, however in this case the callback must do + * any processing required by the chunk (e.g. by calling the appropriate + * png_set_ APIs.) + * + * There is no write support - on write, by default, all the chunks in the + * 'unknown' list are written in the specified position. + * + * The integer return from the callback function is interpreted thus: + * + * negative: An error occurred; png_chunk_error will be called. + * zero: The chunk was not handled, the chunk will be saved. A critical + * chunk will cause an error at this point unless it is to be saved. + * positive: The chunk was handled, libpng will ignore/discard it. + * + * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about + * how this behavior will change in libpng 1.7 + */ +PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr, + png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr)); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +/* Sets the function callbacks for the push reader, and a pointer to a + * user-defined structure available to the callback functions. + */ +PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr, + png_voidp progressive_ptr, png_progressive_info_ptr info_fn, + png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); + +/* Returns the user pointer associated with the push read functions */ +PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, + (png_const_structrp png_ptr)); + +/* Function to be called when data becomes available */ +PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr, + png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)); + +/* A function which may be called *only* within png_process_data to stop the + * processing of any more data. The function returns the number of bytes + * remaining, excluding any that libpng has cached internally. A subsequent + * call to png_process_data must supply these bytes again. If the argument + * 'save' is set to true the routine will first save all the pending data and + * will always return 0. + */ +PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save)); + +/* A function which may be called *only* outside (after) a call to + * png_process_data. It returns the number of bytes of data to skip in the + * input. Normally it will return 0, but if it returns a non-zero value the + * application must skip than number of bytes of input data and pass the + * following data to the next call to png_process_data. + */ +PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp)); + +/* Function that combines rows. 'new_row' is a flag that should come from + * the callback and be non-NULL if anything needs to be done; the library + * stores its own version of the new data internally and ignores the passed + * in value. + */ +PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr, + png_bytep old_row, png_const_bytep new_row)); +#endif /* PROGRESSIVE_READ */ + +PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); +/* Added at libpng version 1.4.0 */ +PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); + +/* Added at libpng version 1.2.4 */ +PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); + +/* Frees a pointer allocated by png_malloc() */ +PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr)); + +/* Free data that was allocated internally */ +PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 free_me, int num)); + +/* Reassign responsibility for freeing existing data, whether allocated + * by libpng or by the application; this works on the png_info structure passed + * in, it does not change the state for other png_info structures. + * + * It is unlikely that this function works correctly as of 1.6.0 and using it + * may result either in memory leaks or double free of allocated data. + */ +PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr, + png_inforp info_ptr, int freer, png_uint_32 mask)); + +/* Assignments for png_data_freer */ +#define PNG_DESTROY_WILL_FREE_DATA 1 +#define PNG_SET_WILL_FREE_DATA 1 +#define PNG_USER_WILL_FREE_DATA 2 +/* Flags for png_ptr->free_me and info_ptr->free_me */ +#define PNG_FREE_HIST 0x0008U +#define PNG_FREE_ICCP 0x0010U +#define PNG_FREE_SPLT 0x0020U +#define PNG_FREE_ROWS 0x0040U +#define PNG_FREE_PCAL 0x0080U +#define PNG_FREE_SCAL 0x0100U +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +# define PNG_FREE_UNKN 0x0200U +#endif +/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */ +#define PNG_FREE_PLTE 0x1000U +#define PNG_FREE_TRNS 0x2000U +#define PNG_FREE_TEXT 0x4000U +#define PNG_FREE_ALL 0x7fffU +#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ + +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED); +PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr, + png_voidp ptr), PNG_DEPRECATED); +#endif + +#ifdef PNG_ERROR_TEXT_SUPPORTED +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr, + png_const_charp error_message), PNG_NORETURN); + +/* The same, but the chunk name is prepended to the error string. */ +PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr, + png_const_charp error_message), PNG_NORETURN); + +#else +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN); +# define png_error(s1,s2) png_err(s1) +# define png_chunk_error(s1,s2) png_err(s1) +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* Non-fatal error in libpng. Can continue, but may have a problem. */ +PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr, + png_const_charp warning_message)); + +/* Non-fatal error in libpng, chunk name is prepended to message. */ +PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr, + png_const_charp warning_message)); +#else +# define png_warning(s1,s2) ((void)(s1)) +# define png_chunk_warning(s1,s2) ((void)(s1)) +#endif + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +/* Benign error in libpng. Can continue, but may have a problem. + * User can choose whether to handle as a fatal error or as a warning. */ +PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr, + png_const_charp warning_message)); + +#ifdef PNG_READ_SUPPORTED +/* Same, chunk name is prepended to message (only during read) */ +PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr, + png_const_charp warning_message)); +#endif + +PNG_EXPORT(109, void, png_set_benign_errors, + (png_structrp png_ptr, int allowed)); +#else +# ifdef PNG_ALLOW_BENIGN_ERRORS +# define png_benign_error png_warning +# define png_chunk_benign_error png_chunk_warning +# else +# define png_benign_error png_error +# define png_chunk_benign_error png_chunk_error +# endif +#endif + +/* The png_set_<chunk> functions are for storing values in the png_info_struct. + * Similarly, the png_get_<chunk> calls are used to read values from the + * png_info_struct, either storing the parameters in the passed variables, or + * setting pointers into the png_info_struct where the data is stored. The + * png_get_<chunk> functions return a non-zero value if the data was available + * in info_ptr, or return zero and do not change any of the parameters if the + * data was not available. + * + * These functions should be used instead of directly accessing png_info + * to avoid problems with future changes in the size and internal layout of + * png_info_struct. + */ +/* Returns "flag" if chunk data is valid in info_ptr. */ +PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 flag)); + +/* Returns number of bytes needed to hold a transformed row. */ +PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* Returns row_pointers, which is an array of pointers to scanlines that was + * returned from png_read_png(). + */ +PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Set row_pointers, which is an array of pointers to scanlines for use + * by png_write_png(). + */ +PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytepp row_pointers)); +#endif + +/* Returns number of color channels in image. */ +PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Returns image width in pixels. */ +PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image height in pixels. */ +PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image bit_depth. */ +PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image color_type. */ +PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image filter_type. */ +PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image interlace_type. */ +PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image compression_type. */ +PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); + +/* Returns image resolution in pixels per meter, from pHYs chunk data. */ +PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +/* Returns pixel aspect ratio, computed from pHYs chunk data. */ +PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) + +/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ +PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); +PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +#endif /* EASY_ACCESS */ + +#ifdef PNG_READ_SUPPORTED +/* Returns pointer to signature string read from PNG header */ +PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr, + png_const_inforp info_ptr)); +#endif + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr, + png_inforp info_ptr, png_color_16p *background)); +#endif + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_color_16p background)); +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, + double *red_y, double *green_x, double *green_y, double *blue_x, + double *blue_y)) +PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, + double *green_X, double *green_Y, double *green_Z, double *blue_X, + double *blue_Y, double *blue_Z)) +PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_white_x, png_fixed_point *int_white_y, + png_fixed_point *int_red_x, png_fixed_point *int_red_y, + png_fixed_point *int_green_x, png_fixed_point *int_green_y, + png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)) +PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_red_X, png_fixed_point *int_red_Y, + png_fixed_point *int_red_Z, png_fixed_point *int_green_X, + png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, + png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, + png_fixed_point *int_blue_Z)) +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr, + png_inforp info_ptr, + double white_x, double white_y, double red_x, double red_y, double green_x, + double green_y, double blue_x, double blue_y)) +PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr, + png_inforp info_ptr, double red_X, double red_Y, double red_Z, + double green_X, double green_Y, double green_Z, double blue_X, + double blue_Y, double blue_Z)) +PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_white_x, + png_fixed_point int_white_y, png_fixed_point int_red_x, + png_fixed_point int_red_y, png_fixed_point int_green_x, + png_fixed_point int_green_y, png_fixed_point int_blue_x, + png_fixed_point int_blue_y)) +PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, + png_fixed_point int_red_Z, png_fixed_point int_green_X, + png_fixed_point int_green_Y, png_fixed_point int_green_Z, + png_fixed_point int_blue_X, png_fixed_point int_blue_Y, + png_fixed_point int_blue_Z)) +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr, + png_const_inforp info_ptr, double *file_gamma)) +PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_file_gamma)) +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr, + png_inforp info_ptr, double file_gamma)) +PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, png_fixed_point int_file_gamma)) +#endif + +#ifdef PNG_hIST_SUPPORTED +PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_16p *hist)); +#endif + +#ifdef PNG_hIST_SUPPORTED +PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_uint_16p hist)); +#endif + +PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, + int *bit_depth, int *color_type, int *interlace_method, + int *compression_method, int *filter_method)); + +PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_method, int compression_method, + int filter_method)); + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, + int *unit_type)); +#endif + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr, + png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, + int unit_type)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, + png_int_32 *X1, int *type, int *nparams, png_charp *units, + png_charpp *params)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, + int type, int nparams, png_const_charp units, png_charpp params)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, + int *unit_type)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr, + png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); +#endif + +PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr, + png_inforp info_ptr, png_colorp *palette, int *num_palette)); + +PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr, + png_inforp info_ptr, png_const_colorp palette, int num_palette)); + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_color_8p *sig_bit)); +#endif + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_color_8p sig_bit)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr, + png_const_inforp info_ptr, int *file_srgb_intent)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr, + png_inforp info_ptr, int srgb_intent)); +PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr, + png_inforp info_ptr, int srgb_intent)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr, + png_inforp info_ptr, png_charpp name, int *compression_type, + png_bytepp profile, png_uint_32 *proflen)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_charp name, int compression_type, + png_const_bytep profile, png_uint_32 proflen)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_sPLT_tpp entries)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)); +#endif + +#ifdef PNG_TEXT_SUPPORTED +/* png_get_text also returns the number of text chunks in *num_text */ +PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr, + png_inforp info_ptr, png_textp *text_ptr, int *num_text)); +#endif + +/* Note while png_set_text() will accept a structure whose text, + * language, and translated keywords are NULL pointers, the structure + * returned by png_get_text will always contain regular + * zero-terminated C strings. They might be empty strings but + * they will never be NULL pointers. + */ + +#ifdef PNG_TEXT_SUPPORTED +PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_textp text_ptr, int num_text)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr, + png_inforp info_ptr, png_timep *mod_time)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_timep mod_time)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr, + png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, + png_color_16p *trans_color)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr, + png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, + png_const_color_16p trans_color)); +#endif + +#ifdef PNG_sCAL_SUPPORTED +PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr, + png_const_inforp info_ptr, int *unit, double *width, double *height)) +#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ + defined(PNG_FLOATING_POINT_SUPPORTED) +/* NOTE: this API is currently implemented using floating point arithmetic, + * consequently it can only be used on systems with floating point support. + * In any case the range of values supported by png_fixed_point is small and it + * is highly recommended that png_get_sCAL_s be used instead. + */ +PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, + png_fixed_point *width, png_fixed_point *height)) +#endif +PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, + (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, + png_charpp swidth, png_charpp sheight)); + +PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, double width, double height)) +PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, png_fixed_point width, + png_fixed_point height)) +PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr, + png_inforp info_ptr, int unit, + png_const_charp swidth, png_const_charp sheight)); +#endif /* sCAL */ + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED +/* Provide the default handling for all unknown chunks or, optionally, for + * specific unknown chunks. + * + * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was + * ignored and the default was used, the per-chunk setting only had an effect on + * write. If you wish to have chunk-specific handling on read in code that must + * work on earlier versions you must use a user chunk callback to specify the + * desired handling (keep or discard.) + * + * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The + * parameter is interpreted as follows: + * + * READ: + * PNG_HANDLE_CHUNK_AS_DEFAULT: + * Known chunks: do normal libpng processing, do not keep the chunk (but + * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED) + * Unknown chunks: for a specific chunk use the global default, when used + * as the default discard the chunk data. + * PNG_HANDLE_CHUNK_NEVER: + * Discard the chunk data. + * PNG_HANDLE_CHUNK_IF_SAFE: + * Keep the chunk data if the chunk is not critical else raise a chunk + * error. + * PNG_HANDLE_CHUNK_ALWAYS: + * Keep the chunk data. + * + * If the chunk data is saved it can be retrieved using png_get_unknown_chunks, + * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent + * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks + * it simply resets the behavior to the libpng default. + * + * INTERACTION WTIH USER CHUNK CALLBACKS: + * The per-chunk handling is always used when there is a png_user_chunk_ptr + * callback and the callback returns 0; the chunk is then always stored *unless* + * it is critical and the per-chunk setting is other than ALWAYS. Notice that + * the global default is *not* used in this case. (In effect the per-chunk + * value is incremented to at least IF_SAFE.) + * + * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and + * per-chunk defaults will be honored. If you want to preserve the current + * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE + * as the default - if you don't do this libpng 1.6 will issue a warning. + * + * If you want unhandled unknown chunks to be discarded in libpng 1.6 and + * earlier simply return '1' (handled). + * + * PNG_HANDLE_AS_UNKNOWN_SUPPORTED: + * If this is *not* set known chunks will always be handled by libpng and + * will never be stored in the unknown chunk list. Known chunks listed to + * png_set_keep_unknown_chunks will have no effect. If it is set then known + * chunks listed with a keep other than AS_DEFAULT will *never* be processed + * by libpng, in addition critical chunks must either be processed by the + * callback or saved. + * + * The IHDR and IEND chunks must not be listed. Because this turns off the + * default handling for chunks that would otherwise be recognized the + * behavior of libpng transformations may well become incorrect! + * + * WRITE: + * When writing chunks the options only apply to the chunks specified by + * png_set_unknown_chunks (below), libpng will *always* write known chunks + * required by png_set_ calls and will always write the core critical chunks + * (as required for PLTE). + * + * Each chunk in the png_set_unknown_chunks list is looked up in the + * png_set_keep_unknown_chunks list to find the keep setting, this is then + * interpreted as follows: + * + * PNG_HANDLE_CHUNK_AS_DEFAULT: + * Write safe-to-copy chunks and write other chunks if the global + * default is set to _ALWAYS, otherwise don't write this chunk. + * PNG_HANDLE_CHUNK_NEVER: + * Do not write the chunk. + * PNG_HANDLE_CHUNK_IF_SAFE: + * Write the chunk if it is safe-to-copy, otherwise do not write it. + * PNG_HANDLE_CHUNK_ALWAYS: + * Write the chunk. + * + * Note that the default behavior is effectively the opposite of the read case - + * in read unknown chunks are not stored by default, in write they are written + * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different + * - on write the safe-to-copy bit is checked, on read the critical bit is + * checked and on read if the chunk is critical an error will be raised. + * + * num_chunks: + * =========== + * If num_chunks is positive, then the "keep" parameter specifies the manner + * for handling only those chunks appearing in the chunk_list array, + * otherwise the chunk list array is ignored. + * + * If num_chunks is 0 the "keep" parameter specifies the default behavior for + * unknown chunks, as described above. + * + * If num_chunks is negative, then the "keep" parameter specifies the manner + * for handling all unknown chunks plus all chunks recognized by libpng + * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to + * be processed by libpng. + */ +PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr, + int keep, png_const_bytep chunk_list, int num_chunks)); + +/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned; + * the result is therefore true (non-zero) if special handling is required, + * false for the default handling. + */ +PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr, + png_const_bytep chunk_name)); +#endif + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr, + png_inforp info_ptr, png_const_unknown_chunkp unknowns, + int num_unknowns)); + /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added + * unknowns to the location currently stored in the png_struct. This is + * invariably the wrong value on write. To fix this call the following API + * for each chunk in the list with the correct location. If you know your + * code won't be compiled on earlier versions you can rely on + * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing + * the correct thing. + */ + +PNG_EXPORT(175, void, png_set_unknown_chunk_location, + (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)); + +PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr, + png_inforp info_ptr, png_unknown_chunkpp entries)); +#endif + +/* Png_free_data() will turn off the "valid" flag for anything it frees. + * If you need to turn it off for a chunk that your application has freed, + * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); + */ +PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr, + png_inforp info_ptr, int mask)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* The "params" pointer is currently not used and is for future expansion. */ +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr, + int transforms, png_voidp params)); +#endif +#ifdef PNG_WRITE_SUPPORTED +PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr, + int transforms, png_voidp params)); +#endif +#endif + +PNG_EXPORT(180, png_const_charp, png_get_copyright, + (png_const_structrp png_ptr)); +PNG_EXPORT(181, png_const_charp, png_get_header_ver, + (png_const_structrp png_ptr)); +PNG_EXPORT(182, png_const_charp, png_get_header_version, + (png_const_structrp png_ptr)); +PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, + (png_const_structrp png_ptr)); + +#ifdef PNG_MNG_FEATURES_SUPPORTED +PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr, + png_uint_32 mng_features_permitted)); +#endif + +/* For use in png_set_keep_unknown, added to version 1.2.6 */ +#define PNG_HANDLE_CHUNK_AS_DEFAULT 0 +#define PNG_HANDLE_CHUNK_NEVER 1 +#define PNG_HANDLE_CHUNK_IF_SAFE 2 +#define PNG_HANDLE_CHUNK_ALWAYS 3 +#define PNG_HANDLE_CHUNK_LAST 4 + +/* Strip the prepended error numbers ("#nnn ") from error and warning + * messages before passing them to the error or warning handler. + */ +#ifdef PNG_ERROR_NUMBERS_SUPPORTED +PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr, + png_uint_32 strip_mode)); +#endif + +/* Added in libpng-1.2.6 */ +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr, + png_uint_32 user_width_max, png_uint_32 user_height_max)); +PNG_EXPORT(187, png_uint_32, png_get_user_width_max, + (png_const_structrp png_ptr)); +PNG_EXPORT(188, png_uint_32, png_get_user_height_max, + (png_const_structrp png_ptr)); +/* Added in libpng-1.4.0 */ +PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr, + png_uint_32 user_chunk_cache_max)); +PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, + (png_const_structrp png_ptr)); +/* Added in libpng-1.4.1 */ +PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr, + png_alloc_size_t user_chunk_cache_max)); +PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, + (png_const_structrp png_ptr)); +#endif + +#if defined(PNG_INCH_CONVERSIONS_SUPPORTED) +PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, + (png_const_structrp png_ptr, png_const_inforp info_ptr)); + +PNG_FP_EXPORT(196, float, png_get_x_offset_inches, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#endif + +PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr, + png_const_inforp info_ptr)) +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, + (png_const_structrp png_ptr, png_const_inforp info_ptr)) +#endif + +# ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr, + png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, + int *unit_type)); +# endif /* pHYs */ +#endif /* INCH_CONVERSIONS */ + +/* Added in libpng-1.4.0 */ +#ifdef PNG_IO_STATE_SUPPORTED +PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr)); + +/* Removed from libpng 1.6; use png_get_io_chunk_type. */ +PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr), + PNG_DEPRECATED) + +PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, + (png_const_structrp png_ptr)); + +/* The flags returned by png_get_io_state() are the following: */ +# define PNG_IO_NONE 0x0000 /* no I/O at this moment */ +# define PNG_IO_READING 0x0001 /* currently reading */ +# define PNG_IO_WRITING 0x0002 /* currently writing */ +# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ +# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ +# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ +# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ +# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ +# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ +#endif /* IO_STATE */ + +/* Interlace support. The following macros are always defined so that if + * libpng interlace handling is turned off the macros may be used to handle + * interlaced images within the application. + */ +#define PNG_INTERLACE_ADAM7_PASSES 7 + +/* Two macros to return the first row and first column of the original, + * full, image which appears in a given pass. 'pass' is in the range 0 + * to 6 and the result is in the range 0 to 7. + */ +#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7) + +/* A macro to return the offset between pixels in the output row for a pair of + * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that + * follows. Note that ROW_OFFSET is the offset from one row to the next whereas + * COL_OFFSET is from one column to the next, within a row. + */ +#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8) +#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1)) + +/* Two macros to help evaluate the number of rows or columns in each + * pass. This is expressed as a shift - effectively log2 of the number or + * rows or columns in each 8x8 tile of the original image. + */ +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) + +/* Hence two macros to determine the number of rows or columns in a given + * pass of an image given its height or width. In fact these macros may + * return non-zero even though the sub-image is empty, because the other + * dimension may be empty for a small image. + */ +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ + -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ + -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) + +/* For the reader row callbacks (both progressive and sequential) it is + * necessary to find the row in the output image given a row in an interlaced + * image, so two more macros: + */ +#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \ + (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) +#define PNG_COL_FROM_PASS_COL(x_in, pass) \ + (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) + +/* Two macros which return a boolean (0 or 1) saying whether the given row + * or column is in a particular pass. These use a common utility macro that + * returns a mask for a given pass - the offset 'off' selects the row or + * column version. The mask has the appropriate bit set for each column in + * the tile. + */ +#define PNG_PASS_MASK(pass,off) ( \ + ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \ + ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0)) + +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED +/* With these routines we avoid an integer divide, which will be slower on + * most machines. However, it does take more operations than the corresponding + * divide method, so it may be slower on a few RISC systems. There are two + * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. + * + * Note that the rounding factors are NOT supposed to be the same! 128 and + * 32768 are correct for the NODIV code; 127 and 32767 are correct for the + * standard method. + * + * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] + */ + + /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ + +# define png_composite(composite, fg, alpha, bg) \ + { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ + * (png_uint_16)(alpha) \ + + (png_uint_16)(bg)*(png_uint_16)(255 \ + - (png_uint_16)(alpha)) + 128); \ + (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); } + +# define png_composite_16(composite, fg, alpha, bg) \ + { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ + * (png_uint_32)(alpha) \ + + (png_uint_32)(bg)*(65535 \ + - (png_uint_32)(alpha)) + 32768); \ + (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); } + +#else /* Standard method using integer division */ + +# define png_composite(composite, fg, alpha, bg) \ + (composite) = \ + (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \ + (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ + 127) / 255)) + +# define png_composite_16(composite, fg, alpha, bg) \ + (composite) = \ + (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \ + (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \ + 32767) / 65535)) +#endif /* READ_COMPOSITE_NODIV */ + +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); +PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); +PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); +#endif + +PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr, + png_const_bytep buf)); +/* No png_get_int_16 -- may be added if there's a real need for it. */ + +/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); +#endif +#ifdef PNG_SAVE_INT_32_SUPPORTED +PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); +#endif + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); +/* No png_save_int_16 -- may be added if there's a real need for it. */ +#endif + +#ifdef PNG_USE_READ_MACROS +/* Inline macros to do direct reads of bytes from the input buffer. + * The png_get_int_32() routine assumes we are using two's complement + * format for negative values, which is almost certainly true. + */ +# define PNG_get_uint_32(buf) \ + (((png_uint_32)(*(buf)) << 24) + \ + ((png_uint_32)(*((buf) + 1)) << 16) + \ + ((png_uint_32)(*((buf) + 2)) << 8) + \ + ((png_uint_32)(*((buf) + 3)))) + + /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the + * function) incorrectly returned a value of type png_uint_32. + */ +# define PNG_get_uint_16(buf) \ + ((png_uint_16) \ + (((unsigned int)(*(buf)) << 8) + \ + ((unsigned int)(*((buf) + 1))))) + +# define PNG_get_int_32(buf) \ + ((png_int_32)((*(buf) & 0x80) \ + ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \ + : (png_int_32)png_get_uint_32(buf))) + + /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h, + * but defining a macro name prefixed with PNG_PREFIX. + */ +# ifndef PNG_PREFIX +# define png_get_uint_32(buf) PNG_get_uint_32(buf) +# define png_get_uint_16(buf) PNG_get_uint_16(buf) +# define png_get_int_32(buf) PNG_get_int_32(buf) +# endif +#else +# ifdef PNG_PREFIX + /* No macros; revert to the (redefined) function */ +# define PNG_get_uint_32 (png_get_uint_32) +# define PNG_get_uint_16 (png_get_uint_16) +# define PNG_get_int_32 (png_get_int_32) +# endif +#endif + +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED +PNG_EXPORT(242, void, png_set_check_for_invalid_index, + (png_structrp png_ptr, int allowed)); +# ifdef PNG_GET_PALETTE_MAX_SUPPORTED +PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr, + png_const_infop info_ptr)); +# endif +#endif /* CHECK_FOR_INVALID_INDEX */ + +/******************************************************************************* + * Section 5: SIMPLIFIED API + ******************************************************************************* + * + * Please read the documentation in libpng-manual.txt (TODO: write said + * documentation) if you don't understand what follows. + * + * The simplified API hides the details of both libpng and the PNG file format + * itself. It allows PNG files to be read into a very limited number of + * in-memory bitmap formats or to be written from the same formats. If these + * formats do not accomodate your needs then you can, and should, use the more + * sophisticated APIs above - these support a wide variety of in-memory formats + * and a wide variety of sophisticated transformations to those formats as well + * as a wide variety of APIs to manipulate ancillary information. + * + * To read a PNG file using the simplified API: + * + * 1) Declare a 'png_image' structure (see below) on the stack, set the + * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL + * (this is REQUIRED, your program may crash if you don't do it.) + * 2) Call the appropriate png_image_begin_read... function. + * 3) Set the png_image 'format' member to the required sample format. + * 4) Allocate a buffer for the image and, if required, the color-map. + * 5) Call png_image_finish_read to read the image and, if required, the + * color-map into your buffers. + * + * There are no restrictions on the format of the PNG input itself; all valid + * color types, bit depths, and interlace methods are acceptable, and the + * input image is transformed as necessary to the requested in-memory format + * during the png_image_finish_read() step. The only caveat is that if you + * request a color-mapped image from a PNG that is full-color or makes + * complex use of an alpha channel the transformation is extremely lossy and the + * result may look terrible. + * + * To write a PNG file using the simplified API: + * + * 1) Declare a 'png_image' structure on the stack and memset() it to all zero. + * 2) Initialize the members of the structure that describe the image, setting + * the 'format' member to the format of the image samples. + * 3) Call the appropriate png_image_write... function with a pointer to the + * image and, if necessary, the color-map to write the PNG data. + * + * png_image is a structure that describes the in-memory format of an image + * when it is being read or defines the in-memory format of an image that you + * need to write: + */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) + +#define PNG_IMAGE_VERSION 1 + +typedef struct png_control *png_controlp; +typedef struct +{ + png_controlp opaque; /* Initialize to NULL, free with png_image_free */ + png_uint_32 version; /* Set to PNG_IMAGE_VERSION */ + png_uint_32 width; /* Image width in pixels (columns) */ + png_uint_32 height; /* Image height in pixels (rows) */ + png_uint_32 format; /* Image format as defined below */ + png_uint_32 flags; /* A bit mask containing informational flags */ + png_uint_32 colormap_entries; + /* Number of entries in the color-map */ + + /* In the event of an error or warning the following field will be set to a + * non-zero value and the 'message' field will contain a '\0' terminated + * string with the libpng error or warning message. If both warnings and + * an error were encountered, only the error is recorded. If there + * are multiple warnings, only the first one is recorded. + * + * The upper 30 bits of this value are reserved, the low two bits contain + * a value as follows: + */ +# define PNG_IMAGE_WARNING 1 +# define PNG_IMAGE_ERROR 2 + /* + * The result is a two-bit code such that a value more than 1 indicates + * a failure in the API just called: + * + * 0 - no warning or error + * 1 - warning + * 2 - error + * 3 - error preceded by warning + */ +# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1) + + png_uint_32 warning_or_error; + + char message[64]; +} png_image, *png_imagep; + +/* The samples of the image have one to four channels whose components have + * original values in the range 0 to 1.0: + * + * 1: A single gray or luminance channel (G). + * 2: A gray/luminance channel and an alpha channel (GA). + * 3: Three red, green, blue color channels (RGB). + * 4: Three color channels and an alpha channel (RGBA). + * + * The components are encoded in one of two ways: + * + * a) As a small integer, value 0..255, contained in a single byte. For the + * alpha channel the original value is simply value/255. For the color or + * luminance channels the value is encoded according to the sRGB specification + * and matches the 8-bit format expected by typical display devices. + * + * The color/gray channels are not scaled (pre-multiplied) by the alpha + * channel and are suitable for passing to color management software. + * + * b) As a value in the range 0..65535, contained in a 2-byte integer. All + * channels can be converted to the original value by dividing by 65535; all + * channels are linear. Color channels use the RGB encoding (RGB end-points) of + * the sRGB specification. This encoding is identified by the + * PNG_FORMAT_FLAG_LINEAR flag below. + * + * When the simplified API needs to convert between sRGB and linear colorspaces, + * the actual sRGB transfer curve defined in the sRGB specification (see the + * article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2 + * approximation used elsewhere in libpng. + * + * When an alpha channel is present it is expected to denote pixel coverage + * of the color or luminance channels and is returned as an associated alpha + * channel: the color/gray channels are scaled (pre-multiplied) by the alpha + * value. + * + * The samples are either contained directly in the image data, between 1 and 8 + * bytes per pixel according to the encoding, or are held in a color-map indexed + * by bytes in the image data. In the case of a color-map the color-map entries + * are individual samples, encoded as above, and the image data has one byte per + * pixel to select the relevant sample from the color-map. + */ + +/* PNG_FORMAT_* + * + * #defines to be used in png_image::format. Each #define identifies a + * particular layout of sample data and, if present, alpha values. There are + * separate defines for each of the two component encodings. + * + * A format is built up using single bit flag values. All combinations are + * valid. Formats can be built up from the flag values or you can use one of + * the predefined values below. When testing formats always use the FORMAT_FLAG + * macros to test for individual features - future versions of the library may + * add new flags. + * + * When reading or writing color-mapped images the format should be set to the + * format of the entries in the color-map then png_image_{read,write}_colormap + * called to read or write the color-map and set the format correctly for the + * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly! + * + * NOTE: libpng can be built with particular features disabled. If you see + * compiler errors because the definition of one of the following flags has been + * compiled out it is because libpng does not have the required support. It is + * possible, however, for the libpng configuration to enable the format on just + * read or just write; in that case you may see an error at run time. You can + * guard against this by checking for the definition of the appropriate + * "_SUPPORTED" macro, one of: + * + * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED + */ +#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */ +#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */ +#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */ +#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */ + +#ifdef PNG_FORMAT_BGR_SUPPORTED +# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */ +#endif + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED +# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */ +#endif + +/* Commonly used formats have predefined macros. + * + * First the single byte (sRGB) formats: + */ +#define PNG_FORMAT_GRAY 0 +#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA +#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) +#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR +#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) +#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) +#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) + +/* Then the linear 2-byte formats. When naming these "Y" is used to + * indicate a luminance (gray) channel. + */ +#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR +#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) +#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) +#define PNG_FORMAT_LINEAR_RGB_ALPHA \ + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA) + +/* With color-mapped formats the image data is one byte for each pixel, the byte + * is an index into the color-map which is formatted as above. To obtain a + * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP + * to one of the above definitions, or you can use one of the definitions below. + */ +#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) +#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) + +/* PNG_IMAGE macros + * + * These are convenience macros to derive information from a png_image + * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the + * actual image sample values - either the entries in the color-map or the + * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values + * for the pixels and will always return 1 for color-mapped formats. The + * remaining macros return information about the rows in the image and the + * complete image. + * + * NOTE: All the macros that take a png_image::format parameter are compile time + * constants if the format parameter is, itself, a constant. Therefore these + * macros can be used in array declarations and case labels where required. + * Similarly the macros are also pre-processor constants (sizeof is not used) so + * they can be used in #if tests. + * + * First the information about the samples. + */ +#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\ + (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1) + /* Return the total number of channels in a given format: 1..4 */ + +#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\ + ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1) + /* Return the size in bytes of a single component of a pixel or color-map + * entry (as appropriate) in the image: 1 or 2. + */ + +#define PNG_IMAGE_SAMPLE_SIZE(fmt)\ + (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)) + /* This is the size of the sample data for one sample. If the image is + * color-mapped it is the size of one color-map entry (and image pixels are + * one byte in size), otherwise it is the size of one image pixel. + */ + +#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\ + (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256) + /* The maximum size of the color-map required by the format expressed in a + * count of components. This can be used to compile-time allocate a + * color-map: + * + * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)]; + * + * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)]; + * + * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the + * information from one of the png_image_begin_read_ APIs and dynamically + * allocate the required memory. + */ + +/* Corresponding information about the pixels */ +#define PNG_IMAGE_PIXEL_(test,fmt)\ + (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt)) + +#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\ + PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt) + /* The number of separate channels (components) in a pixel; 1 for a + * color-mapped image. + */ + +#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\ + PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt) + /* The size, in bytes, of each component in a pixel; 1 for a color-mapped + * image. + */ + +#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt) + /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */ + +/* Information about the whole row, or whole image */ +#define PNG_IMAGE_ROW_STRIDE(image)\ + (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width) + /* Return the total number of components in a single row of the image; this + * is the minimum 'row stride', the minimum count of components between each + * row. For a color-mapped image this is the minimum number of bytes in a + * row. + * + * WARNING: this macro overflows for some images with more than one component + * and very large image widths. libpng will refuse to process an image where + * this macro would overflow. + */ + +#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\ + (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride)) + /* Return the size, in bytes, of an image buffer given a png_image and a row + * stride - the number of components to leave space for in each row. + * + * WARNING: this macro overflows a 32-bit integer for some large PNG images, + * libpng will refuse to process an image where such an overflow would occur. + */ + +#define PNG_IMAGE_SIZE(image)\ + PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image)) + /* Return the size, in bytes, of the image in memory given just a png_image; + * the row stride is the minimum stride required for the image. + */ + +#define PNG_IMAGE_COLORMAP_SIZE(image)\ + (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries) + /* Return the size, in bytes, of the color-map of this image. If the image + * format is not a color-map format this will return a size sufficient for + * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if + * you don't want to allocate a color-map in this case. + */ + +/* PNG_IMAGE_FLAG_* + * + * Flags containing additional information about the image are held in the + * 'flags' field of png_image. + */ +#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01 + /* This indicates the the RGB values of the in-memory bitmap do not + * correspond to the red, green and blue end-points defined by sRGB. + */ + +#define PNG_IMAGE_FLAG_FAST 0x02 + /* On write emphasise speed over compression; the resultant PNG file will be + * larger but will be produced significantly faster, particular for large + * images. Do not use this option for images which will be distributed, only + * used it when producing intermediate files that will be read back in + * repeatedly. For a typical 24-bit image the option will double the read + * speed at the cost of increasing the image size by 25%, however for many + * more compressible images the PNG file can be 10 times larger with only a + * slight speed gain. + */ + +#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04 + /* On read if the image is a 16-bit per component image and there is no gAMA + * or sRGB chunk assume that the components are sRGB encoded. Notice that + * images output by the simplified API always have gamma information; setting + * this flag only affects the interpretation of 16-bit images from an + * external source. It is recommended that the application expose this flag + * to the user; the user can normally easily recognize the difference between + * linear and sRGB encoding. This flag has no effect on write - the data + * passed to the write APIs must have the correct encoding (as defined + * above.) + * + * If the flag is not set (the default) input 16-bit per component data is + * assumed to be linear. + * + * NOTE: the flag can only be set after the png_image_begin_read_ call, + * because that call initializes the 'flags' field. + */ + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +/* READ APIs + * --------- + * + * The png_image passed to the read APIs must have been initialized by setting + * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.) + */ +#ifdef PNG_STDIO_SUPPORTED +PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image, + const char *file_name)); + /* The named file is opened for read and the image header is filled in + * from the PNG header in the file. + */ + +PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image, + FILE* file)); + /* The PNG header is read from the stdio FILE object. */ +#endif /* STDIO */ + +PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image, + png_const_voidp memory, png_size_t size)); + /* The PNG header is read from the given memory buffer. */ + +PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image, + png_const_colorp background, void *buffer, png_int_32 row_stride, + void *colormap)); + /* Finish reading the image into the supplied buffer and clean up the + * png_image structure. + * + * row_stride is the step, in byte or 2-byte units as appropriate, + * between adjacent rows. A positive stride indicates that the top-most row + * is first in the buffer - the normal top-down arrangement. A negative + * stride indicates that the bottom-most row is first in the buffer. + * + * background need only be supplied if an alpha channel must be removed from + * a png_byte format and the removal is to be done by compositing on a solid + * color; otherwise it may be NULL and any composition will be done directly + * onto the buffer. The value is an sRGB color to use for the background, + * for grayscale output the green channel is used. + * + * background must be supplied when an alpha channel must be removed from a + * single byte color-mapped output format, in other words if: + * + * 1) The original format from png_image_begin_read_from_* had + * PNG_FORMAT_FLAG_ALPHA set. + * 2) The format set by the application does not. + * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and + * PNG_FORMAT_FLAG_LINEAR *not* set. + * + * For linear output removing the alpha channel is always done by compositing + * on black and background is ignored. + * + * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must + * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE. + * image->colormap_entries will be updated to the actual number of entries + * written to the colormap; this may be less than the original value. + */ + +PNG_EXPORT(238, void, png_image_free, (png_imagep image)); + /* Free any data allocated by libpng in image->opaque, setting the pointer to + * NULL. May be called at any time after the structure is initialized. + */ +#endif /* SIMPLIFIED_READ */ + +#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED +/* WRITE APIS + * ---------- + * For write you must initialize a png_image structure to describe the image to + * be written. To do this use memset to set the whole structure to 0 then + * initialize fields describing your image. + * + * version: must be set to PNG_IMAGE_VERSION + * opaque: must be initialized to NULL + * width: image width in pixels + * height: image height in rows + * format: the format of the data (image and color-map) you wish to write + * flags: set to 0 unless one of the defined flags applies; set + * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB + * values do not correspond to the colors in sRGB. + * colormap_entries: set to the number of entries in the color-map (0 to 256) + */ +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image, + const char *file, int convert_to_8bit, const void *buffer, + png_int_32 row_stride, const void *colormap)); + /* Write the image to the named file. */ + +PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file, + int convert_to_8_bit, const void *buffer, png_int_32 row_stride, + const void *colormap)); + /* Write the image to the given (FILE*). */ +#endif /* SIMPLIFIED_WRITE_STDIO */ + +/* With all write APIs if image is in one of the linear formats with 16-bit + * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG + * gamma encoded according to the sRGB specification, otherwise a 16-bit linear + * encoded PNG file is written. + * + * With color-mapped data formats the colormap parameter point to a color-map + * with at least image->colormap_entries encoded in the specified format. If + * the format is linear the written PNG color-map will be converted to sRGB + * regardless of the convert_to_8_bit flag. + * + * With all APIs row_stride is handled as in the read APIs - it is the spacing + * from one row to the next in component sized units (1 or 2 bytes) and if + * negative indicates a bottom-up row layout in the buffer. If row_stride is + * zero, libpng will calculate it for you from the image width and number of + * channels. + * + * Note that the write API does not support interlacing, sub-8-bit pixels or + * most ancillary chunks. If you need to write text chunks (e.g. for copyright + * notices) you need to use one of the other APIs. + */ + +PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory, + png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit, + const void *buffer, png_int_32 row_stride, const void *colormap)); + /* Write the image to the given memory buffer. The function both writes the + * whole PNG data stream to *memory and updates *memory_bytes with the count + * of bytes written. + * + * 'memory' may be NULL. In this case *memory_bytes is not read however on + * success the number of bytes which would have been written will still be + * stored in *memory_bytes. On failure *memory_bytes will contain 0. + * + * If 'memory' is not NULL it must point to memory[*memory_bytes] of + * writeable memory. + * + * If the function returns success memory[*memory_bytes] (if 'memory' is not + * NULL) contains the written PNG data. *memory_bytes will always be less + * than or equal to the original value. + * + * If the function returns false and *memory_bytes was not changed an error + * occured during write. If *memory_bytes was changed, or is not 0 if + * 'memory' was NULL, the write would have succeeded but for the memory + * buffer being too small. *memory_bytes contains the required number of + * bytes and will be bigger that the original value. + */ + +#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\ + row_stride, colormap)\ + png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\ + row_stride, colormap) + /* Return the amount of memory in 'size' required to compress this image. + * The png_image structure 'image' must be filled in as in the above + * function and must not be changed before the actual write call, the buffer + * and all other parameters must also be identical to that in the final + * write call. The 'size' variable need not be initialized. + * + * NOTE: the macro returns true/false, if false is returned 'size' will be + * set to zero and the write failed and probably will fail if tried again. + */ + +/* You can pre-allocate the buffer by making sure it is of sufficient size + * regardless of the amount of compression achieved. The buffer size will + * always be bigger than the original image and it will never be filled. The + * following macros are provided to assist in allocating the buffer. + */ +#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height) + /* The number of uncompressed bytes in the PNG byte encoding of the image; + * uncompressing the PNG IDAT data will give this number of bytes. + * + * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this + * macro can because of the extra bytes used in the PNG byte encoding. You + * need to avoid this macro if your image size approaches 2^30 in width or + * height. The same goes for the remainder of these macros; they all produce + * bigger numbers than the actual in-memory image size. + */ +#ifndef PNG_ZLIB_MAX_SIZE +# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U) + /* An upper bound on the number of compressed bytes given 'b' uncompressed + * bytes. This is based on deflateBounds() in zlib; different + * implementations of zlib compression may conceivably produce more data so + * if your zlib implementation is not zlib itself redefine this macro + * appropriately. + */ +#endif + +#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\ + PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image)) + /* An upper bound on the size of the data in the PNG IDAT chunks. */ + +#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\ + ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\ + (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\ + 12U+3U*(image).colormap_entries/*PLTE data*/+\ + (((image).format&PNG_FORMAT_FLAG_ALPHA)?\ + 12U/*tRNS*/+(image).colormap_entries:0U):0U)+\ + 12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size)) + /* A helper for the following macro; if your compiler cannot handle the + * following macro use this one with the result of + * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most + * compilers should handle this just fine.) + */ + +#define PNG_IMAGE_PNG_SIZE_MAX(image)\ + PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image)) + /* An upper bound on the total length of the PNG data stream for 'image'. + * The result is of type png_alloc_size_t, on 32-bit systems this may + * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will + * run out of buffer space but return a corrected size which should work. + */ +#endif /* SIMPLIFIED_WRITE */ +/******************************************************************************* + * END OF SIMPLIFIED API + ******************************************************************************/ +#endif /* SIMPLIFIED_{READ|WRITE} */ + +/******************************************************************************* + * Section 6: IMPLEMENTATION OPTIONS + ******************************************************************************* + * + * Support for arbitrary implementation-specific optimizations. The API allows + * particular options to be turned on or off. 'Option' is the number of the + * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given + * by the PNG_OPTION_ defines below. + * + * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions, + * are detected at run time, however sometimes it may be impossible + * to do this in user mode, in which case it is necessary to discover + * the capabilities in an OS specific way. Such capabilities are + * listed here when libpng has support for them and must be turned + * ON by the application if present. + * + * SOFTWARE: sometimes software optimizations actually result in performance + * decrease on some architectures or systems, or with some sets of + * PNG images. 'Software' options allow such optimizations to be + * selected at run time. + */ +#ifdef PNG_SET_OPTION_SUPPORTED +#ifdef PNG_ARM_NEON_API_SUPPORTED +# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ +#endif +#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */ +#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */ +#define PNG_OPTION_NEXT 6 /* Next option - numbers must be even */ + +/* Return values: NOTE: there are four values and 'off' is *not* zero */ +#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */ +#define PNG_OPTION_INVALID 1 /* Option number out of range */ +#define PNG_OPTION_OFF 2 +#define PNG_OPTION_ON 3 + +PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option, + int onoff)); +#endif /* SET_OPTION */ + +/******************************************************************************* + * END OF HARDWARE AND SOFTWARE OPTIONS + ******************************************************************************/ + +/* Maintainer: Put new public prototypes here ^, in libpng.3, in project + * defs, and in scripts/symbols.def. + */ + +/* The last ordinal number (this is the *last* one already used; the next + * one to use is one more than this.) + */ +#ifdef PNG_EXPORT_LAST_ORDINAL + PNG_EXPORT_LAST_ORDINAL(245); +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* PNG_VERSION_INFO_ONLY */ +/* Do not put anything past this line */ +#endif /* PNG_H */ diff --git a/thirdparty/libpng/pngconf.h b/thirdparty/libpng/pngconf.h new file mode 100644 index 0000000000..b0ccc8c25e --- /dev/null +++ b/thirdparty/libpng/pngconf.h @@ -0,0 +1,622 @@ + +/* pngconf.h - machine configurable file for libpng + * + * libpng version 1.6.23, June 9, 2016 + * + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Any machine specific code is near the front of this file, so if you + * are configuring libpng for a machine, you may want to read the section + * starting here down to where it starts to typedef png_color, png_text, + * and png_info. + */ + +#ifndef PNGCONF_H +#define PNGCONF_H + +#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */ + +/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C + * compiler for correct compilation. The following header files are required by + * the standard. If your compiler doesn't provide these header files, or they + * do not match the standard, you will need to provide/improve them. + */ +#include <limits.h> +#include <stddef.h> + +/* Library header files. These header files are all defined by ISOC90; libpng + * expects conformant implementations, however, an ISOC90 conformant system need + * not provide these header files if the functionality cannot be implemented. + * In this case it will be necessary to disable the relevant parts of libpng in + * the build of pnglibconf.h. + * + * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not + * include this unnecessary header file. + */ + +#ifdef PNG_STDIO_SUPPORTED + /* Required for the definition of FILE: */ +# include <stdio.h> +#endif + +#ifdef PNG_SETJMP_SUPPORTED + /* Required for the definition of jmp_buf and the declaration of longjmp: */ +# include <setjmp.h> +#endif + +#ifdef PNG_CONVERT_tIME_SUPPORTED + /* Required for struct tm: */ +# include <time.h> +#endif + +#endif /* PNG_BUILDING_SYMBOL_TABLE */ + +/* Prior to 1.6.0 it was possible to turn off 'const' in declarations using + * PNG_NO_CONST; this is no longer supported except for data declarations which + * apparently still cause problems in 2011 on some compilers. + */ +#define PNG_CONST const /* backward compatibility only */ + +/* This controls optimization of the reading of 16-bit and 32-bit values + * from PNG files. It can be set on a per-app-file basis - it + * just changes whether a macro is used when the function is called. + * The library builder sets the default; if read functions are not + * built into the library the macro implementation is forced on. + */ +#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED +# define PNG_USE_READ_MACROS +#endif +#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS) +# if PNG_DEFAULT_READ_MACROS +# define PNG_USE_READ_MACROS +# endif +#endif + +/* COMPILER SPECIFIC OPTIONS. + * + * These options are provided so that a variety of difficult compilers + * can be used. Some are fixed at build time (e.g. PNG_API_RULE + * below) but still have compiler specific implementations, others + * may be changed on a per-file basis when compiling against libpng. + */ + +/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect + * against legacy (pre ISOC90) compilers that did not understand function + * prototypes. It is not required for modern C compilers. + */ +#ifndef PNGARG +# define PNGARG(arglist) arglist +#endif + +/* Function calling conventions. + * ============================= + * Normally it is not necessary to specify to the compiler how to call + * a function - it just does it - however on x86 systems derived from + * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems + * and some others) there are multiple ways to call a function and the + * default can be changed on the compiler command line. For this reason + * libpng specifies the calling convention of every exported function and + * every function called via a user supplied function pointer. This is + * done in this file by defining the following macros: + * + * PNGAPI Calling convention for exported functions. + * PNGCBAPI Calling convention for user provided (callback) functions. + * PNGCAPI Calling convention used by the ANSI-C library (required + * for longjmp callbacks and sometimes used internally to + * specify the calling convention for zlib). + * + * These macros should never be overridden. If it is necessary to + * change calling convention in a private build this can be done + * by setting PNG_API_RULE (which defaults to 0) to one of the values + * below to select the correct 'API' variants. + * + * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout. + * This is correct in every known environment. + * PNG_API_RULE=1 Use the operating system convention for PNGAPI and + * the 'C' calling convention (from PNGCAPI) for + * callbacks (PNGCBAPI). This is no longer required + * in any known environment - if it has to be used + * please post an explanation of the problem to the + * libpng mailing list. + * + * These cases only differ if the operating system does not use the C + * calling convention, at present this just means the above cases + * (x86 DOS/Windows sytems) and, even then, this does not apply to + * Cygwin running on those systems. + * + * Note that the value must be defined in pnglibconf.h so that what + * the application uses to call the library matches the conventions + * set when building the library. + */ + +/* Symbol export + * ============= + * When building a shared library it is almost always necessary to tell + * the compiler which symbols to export. The png.h macro 'PNG_EXPORT' + * is used to mark the symbols. On some systems these symbols can be + * extracted at link time and need no special processing by the compiler, + * on other systems the symbols are flagged by the compiler and just + * the declaration requires a special tag applied (unfortunately) in a + * compiler dependent way. Some systems can do either. + * + * A small number of older systems also require a symbol from a DLL to + * be flagged to the program that calls it. This is a problem because + * we do not know in the header file included by application code that + * the symbol will come from a shared library, as opposed to a statically + * linked one. For this reason the application must tell us by setting + * the magic flag PNG_USE_DLL to turn on the special processing before + * it includes png.h. + * + * Four additional macros are used to make this happen: + * + * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from + * the build or imported if PNG_USE_DLL is set - compiler + * and system specific. + * + * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to + * 'type', compiler specific. + * + * PNG_DLL_EXPORT Set to the magic to use during a libpng build to + * make a symbol exported from the DLL. Not used in the + * public header files; see pngpriv.h for how it is used + * in the libpng build. + * + * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come + * from a DLL - used to define PNG_IMPEXP when + * PNG_USE_DLL is set. + */ + +/* System specific discovery. + * ========================== + * This code is used at build time to find PNG_IMPEXP, the API settings + * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL + * import processing is possible. On Windows systems it also sets + * compiler-specific macros to the values required to change the calling + * conventions of the various functions. + */ +#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\ + defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) + /* Windows system (DOS doesn't support DLLs). Includes builds under Cygwin or + * MinGW on any architecture currently supported by Windows. Also includes + * Watcom builds but these need special treatment because they are not + * compatible with GCC or Visual C because of different calling conventions. + */ +# if PNG_API_RULE == 2 + /* If this line results in an error, either because __watcall is not + * understood or because of a redefine just below you cannot use *this* + * build of the library with the compiler you are using. *This* build was + * build using Watcom and applications must also be built using Watcom! + */ +# define PNGCAPI __watcall +# endif + +# if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800)) +# define PNGCAPI __cdecl +# if PNG_API_RULE == 1 + /* If this line results in an error __stdcall is not understood and + * PNG_API_RULE should not have been set to '1'. + */ +# define PNGAPI __stdcall +# endif +# else + /* An older compiler, or one not detected (erroneously) above, + * if necessary override on the command line to get the correct + * variants for the compiler. + */ +# ifndef PNGCAPI +# define PNGCAPI _cdecl +# endif +# if PNG_API_RULE == 1 && !defined(PNGAPI) +# define PNGAPI _stdcall +# endif +# endif /* compiler/api */ + + /* NOTE: PNGCBAPI always defaults to PNGCAPI. */ + +# if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD) +# error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed" +# endif + +# if (defined(_MSC_VER) && _MSC_VER < 800) ||\ + (defined(__BORLANDC__) && __BORLANDC__ < 0x500) + /* older Borland and MSC + * compilers used '__export' and required this to be after + * the type. + */ +# ifndef PNG_EXPORT_TYPE +# define PNG_EXPORT_TYPE(type) type PNG_IMPEXP +# endif +# define PNG_DLL_EXPORT __export +# else /* newer compiler */ +# define PNG_DLL_EXPORT __declspec(dllexport) +# ifndef PNG_DLL_IMPORT +# define PNG_DLL_IMPORT __declspec(dllimport) +# endif +# endif /* compiler */ + +#else /* !Windows */ +# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__) +# define PNGAPI _System +# else /* !Windows/x86 && !OS/2 */ + /* Use the defaults, or define PNG*API on the command line (but + * this will have to be done for every compile!) + */ +# endif /* other system, !OS/2 */ +#endif /* !Windows/x86 */ + +/* Now do all the defaulting . */ +#ifndef PNGCAPI +# define PNGCAPI +#endif +#ifndef PNGCBAPI +# define PNGCBAPI PNGCAPI +#endif +#ifndef PNGAPI +# define PNGAPI PNGCAPI +#endif + +/* PNG_IMPEXP may be set on the compilation system command line or (if not set) + * then in an internal header file when building the library, otherwise (when + * using the library) it is set here. + */ +#ifndef PNG_IMPEXP +# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT) + /* This forces use of a DLL, disallowing static linking */ +# define PNG_IMPEXP PNG_DLL_IMPORT +# endif + +# ifndef PNG_IMPEXP +# define PNG_IMPEXP +# endif +#endif + +/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat + * 'attributes' as a storage class - the attributes go at the start of the + * function definition, and attributes are always appended regardless of the + * compiler. This considerably simplifies these macros but may cause problems + * if any compilers both need function attributes and fail to handle them as + * a storage class (this is unlikely.) + */ +#ifndef PNG_FUNCTION +# define PNG_FUNCTION(type, name, args, attributes) attributes type name args +#endif + +#ifndef PNG_EXPORT_TYPE +# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type +#endif + + /* The ordinal value is only relevant when preprocessing png.h for symbol + * table entries, so we discard it here. See the .dfn files in the + * scripts directory. + */ + +#ifndef PNG_EXPORTA +# define PNG_EXPORTA(ordinal, type, name, args, attributes) \ + PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \ + PNG_LINKAGE_API attributes) +#endif + +/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument, + * so make something non-empty to satisfy the requirement: + */ +#define PNG_EMPTY /*empty list*/ + +#define PNG_EXPORT(ordinal, type, name, args) \ + PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY) + +/* Use PNG_REMOVED to comment out a removed interface. */ +#ifndef PNG_REMOVED +# define PNG_REMOVED(ordinal, type, name, args, attributes) +#endif + +#ifndef PNG_CALLBACK +# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args) +#endif + +/* Support for compiler specific function attributes. These are used + * so that where compiler support is available incorrect use of API + * functions in png.h will generate compiler warnings. + * + * Added at libpng-1.2.41. + */ + +#ifndef PNG_NO_PEDANTIC_WARNINGS +# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED +# define PNG_PEDANTIC_WARNINGS_SUPPORTED +# endif +#endif + +#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED + /* Support for compiler specific function attributes. These are used + * so that where compiler support is available, incorrect use of API + * functions in png.h will generate compiler warnings. Added at libpng + * version 1.2.41. Disabling these removes the warnings but may also produce + * less efficient code. + */ +# if defined(__clang__) && defined(__has_attribute) + /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */ +# if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__) +# define PNG_USE_RESULT __attribute__((__warn_unused_result__)) +# endif +# if !defined(PNG_NORETURN) && __has_attribute(__noreturn__) +# define PNG_NORETURN __attribute__((__noreturn__)) +# endif +# if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__) +# define PNG_ALLOCATED __attribute__((__malloc__)) +# endif +# if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__) +# define PNG_DEPRECATED __attribute__((__deprecated__)) +# endif +# if !defined(PNG_PRIVATE) +# ifdef __has_extension +# if __has_extension(attribute_unavailable_with_message) +# define PNG_PRIVATE __attribute__((__unavailable__(\ + "This function is not exported by libpng."))) +# endif +# endif +# endif +# ifndef PNG_RESTRICT +# define PNG_RESTRICT __restrict +# endif + +# elif defined(__GNUC__) +# ifndef PNG_USE_RESULT +# define PNG_USE_RESULT __attribute__((__warn_unused_result__)) +# endif +# ifndef PNG_NORETURN +# define PNG_NORETURN __attribute__((__noreturn__)) +# endif +# if __GNUC__ >= 3 +# ifndef PNG_ALLOCATED +# define PNG_ALLOCATED __attribute__((__malloc__)) +# endif +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __attribute__((__deprecated__)) +# endif +# ifndef PNG_PRIVATE +# if 0 /* Doesn't work so we use deprecated instead*/ +# define PNG_PRIVATE \ + __attribute__((warning("This function is not exported by libpng."))) +# else +# define PNG_PRIVATE \ + __attribute__((__deprecated__)) +# endif +# endif +# if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1)) +# ifndef PNG_RESTRICT +# define PNG_RESTRICT __restrict +# endif +# endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */ +# endif /* __GNUC__ >= 3 */ + +# elif defined(_MSC_VER) && (_MSC_VER >= 1300) +# ifndef PNG_USE_RESULT +# define PNG_USE_RESULT /* not supported */ +# endif +# ifndef PNG_NORETURN +# define PNG_NORETURN __declspec(noreturn) +# endif +# ifndef PNG_ALLOCATED +# if (_MSC_VER >= 1400) +# define PNG_ALLOCATED __declspec(restrict) +# endif +# endif +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __declspec(deprecated) +# endif +# ifndef PNG_PRIVATE +# define PNG_PRIVATE __declspec(deprecated) +# endif +# ifndef PNG_RESTRICT +# if (_MSC_VER >= 1400) +# define PNG_RESTRICT __restrict +# endif +# endif + +# elif defined(__WATCOMC__) +# ifndef PNG_RESTRICT +# define PNG_RESTRICT __restrict +# endif +# endif +#endif /* PNG_PEDANTIC_WARNINGS */ + +#ifndef PNG_DEPRECATED +# define PNG_DEPRECATED /* Use of this function is deprecated */ +#endif +#ifndef PNG_USE_RESULT +# define PNG_USE_RESULT /* The result of this function must be checked */ +#endif +#ifndef PNG_NORETURN +# define PNG_NORETURN /* This function does not return */ +#endif +#ifndef PNG_ALLOCATED +# define PNG_ALLOCATED /* The result of the function is new memory */ +#endif +#ifndef PNG_PRIVATE +# define PNG_PRIVATE /* This is a private libpng function */ +#endif +#ifndef PNG_RESTRICT +# define PNG_RESTRICT /* The C99 "restrict" feature */ +#endif + +#ifndef PNG_FP_EXPORT /* A floating point API. */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +# define PNG_FP_EXPORT(ordinal, type, name, args)\ + PNG_EXPORT(ordinal, type, name, args); +# else /* No floating point APIs */ +# define PNG_FP_EXPORT(ordinal, type, name, args) +# endif +#endif +#ifndef PNG_FIXED_EXPORT /* A fixed point API. */ +# ifdef PNG_FIXED_POINT_SUPPORTED +# define PNG_FIXED_EXPORT(ordinal, type, name, args)\ + PNG_EXPORT(ordinal, type, name, args); +# else /* No fixed point APIs */ +# define PNG_FIXED_EXPORT(ordinal, type, name, args) +# endif +#endif + +#ifndef PNG_BUILDING_SYMBOL_TABLE +/* Some typedefs to get us started. These should be safe on most of the common + * platforms. + * + * png_uint_32 and png_int_32 may, currently, be larger than required to hold a + * 32-bit value however this is not normally advisable. + * + * png_uint_16 and png_int_16 should always be two bytes in size - this is + * verified at library build time. + * + * png_byte must always be one byte in size. + * + * The checks below use constants from limits.h, as defined by the ISOC90 + * standard. + */ +#if CHAR_BIT == 8 && UCHAR_MAX == 255 + typedef unsigned char png_byte; +#else +# error "libpng requires 8-bit bytes" +#endif + +#if INT_MIN == -32768 && INT_MAX == 32767 + typedef int png_int_16; +#elif SHRT_MIN == -32768 && SHRT_MAX == 32767 + typedef short png_int_16; +#else +# error "libpng requires a signed 16-bit type" +#endif + +#if UINT_MAX == 65535 + typedef unsigned int png_uint_16; +#elif USHRT_MAX == 65535 + typedef unsigned short png_uint_16; +#else +# error "libpng requires an unsigned 16-bit type" +#endif + +#if INT_MIN < -2147483646 && INT_MAX > 2147483646 + typedef int png_int_32; +#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646 + typedef long int png_int_32; +#else +# error "libpng requires a signed 32-bit (or more) type" +#endif + +#if UINT_MAX > 4294967294 + typedef unsigned int png_uint_32; +#elif ULONG_MAX > 4294967294 + typedef unsigned long int png_uint_32; +#else +# error "libpng requires an unsigned 32-bit (or more) type" +#endif + +/* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however, + * requires an ISOC90 compiler and relies on consistent behavior of sizeof. + */ +typedef size_t png_size_t; +typedef ptrdiff_t png_ptrdiff_t; + +/* libpng needs to know the maximum value of 'size_t' and this controls the + * definition of png_alloc_size_t, below. This maximum value of size_t limits + * but does not control the maximum allocations the library makes - there is + * direct application control of this through png_set_user_limits(). + */ +#ifndef PNG_SMALL_SIZE_T + /* Compiler specific tests for systems where size_t is known to be less than + * 32 bits (some of these systems may no longer work because of the lack of + * 'far' support; see above.) + */ +# if (defined(__TURBOC__) && !defined(__FLAT__)) ||\ + (defined(_MSC_VER) && defined(MAXSEG_64K)) +# define PNG_SMALL_SIZE_T +# endif +#endif + +/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no + * smaller than png_uint_32. Casts from png_size_t or png_uint_32 to + * png_alloc_size_t are not necessary; in fact, it is recommended not to use + * them at all so that the compiler can complain when something turns out to be + * problematic. + * + * Casts in the other direction (from png_alloc_size_t to png_size_t or + * png_uint_32) should be explicitly applied; however, we do not expect to + * encounter practical situations that require such conversions. + * + * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than + * 4294967295 - i.e. less than the maximum value of png_uint_32. + */ +#ifdef PNG_SMALL_SIZE_T + typedef png_uint_32 png_alloc_size_t; +#else + typedef png_size_t png_alloc_size_t; +#endif + +/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler + * implementations of Intel CPU specific support of user-mode segmented address + * spaces, where 16-bit pointers address more than 65536 bytes of memory using + * separate 'segment' registers. The implementation requires two different + * types of pointer (only one of which includes the segment value.) + * + * If required this support is available in version 1.2 of libpng and may be + * available in versions through 1.5, although the correctness of the code has + * not been verified recently. + */ + +/* Typedef for floating-point numbers that are converted to fixed-point with a + * multiple of 100,000, e.g., gamma + */ +typedef png_int_32 png_fixed_point; + +/* Add typedefs for pointers */ +typedef void * png_voidp; +typedef const void * png_const_voidp; +typedef png_byte * png_bytep; +typedef const png_byte * png_const_bytep; +typedef png_uint_32 * png_uint_32p; +typedef const png_uint_32 * png_const_uint_32p; +typedef png_int_32 * png_int_32p; +typedef const png_int_32 * png_const_int_32p; +typedef png_uint_16 * png_uint_16p; +typedef const png_uint_16 * png_const_uint_16p; +typedef png_int_16 * png_int_16p; +typedef const png_int_16 * png_const_int_16p; +typedef char * png_charp; +typedef const char * png_const_charp; +typedef png_fixed_point * png_fixed_point_p; +typedef const png_fixed_point * png_const_fixed_point_p; +typedef png_size_t * png_size_tp; +typedef const png_size_t * png_const_size_tp; + +#ifdef PNG_STDIO_SUPPORTED +typedef FILE * png_FILE_p; +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +typedef double * png_doublep; +typedef const double * png_const_doublep; +#endif + +/* Pointers to pointers; i.e. arrays */ +typedef png_byte * * png_bytepp; +typedef png_uint_32 * * png_uint_32pp; +typedef png_int_32 * * png_int_32pp; +typedef png_uint_16 * * png_uint_16pp; +typedef png_int_16 * * png_int_16pp; +typedef const char * * png_const_charpp; +typedef char * * png_charpp; +typedef png_fixed_point * * png_fixed_point_pp; +#ifdef PNG_FLOATING_POINT_SUPPORTED +typedef double * * png_doublepp; +#endif + +/* Pointers to pointers to pointers; i.e., pointer to array */ +typedef char * * * png_charppp; + +#endif /* PNG_BUILDING_SYMBOL_TABLE */ + +#endif /* PNGCONF_H */ diff --git a/thirdparty/libpng/pngdebug.h b/thirdparty/libpng/pngdebug.h new file mode 100644 index 0000000000..15a7ed0c95 --- /dev/null +++ b/thirdparty/libpng/pngdebug.h @@ -0,0 +1,153 @@ + +/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c + * + * Last changed in libpng 1.6.8 [December 19, 2013] + * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* Define PNG_DEBUG at compile time for debugging information. Higher + * numbers for PNG_DEBUG mean more debugging information. This has + * only been added since version 0.95 so it is not implemented throughout + * libpng yet, but more support will be added as needed. + * + * png_debug[1-2]?(level, message ,arg{0-2}) + * Expands to a statement (either a simple expression or a compound + * do..while(0) statement) that outputs a message with parameter + * substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG + * is undefined, 0 or 1 every png_debug expands to a simple expression + * (actually ((void)0)). + * + * level: level of detail of message, starting at 0. A level 'n' + * message is preceded by 'n' 3-space indentations (not implemented + * on Microsoft compilers unless PNG_DEBUG_FILE is also + * defined, to allow debug DLL compilation with no standard IO). + * message: a printf(3) style text string. A trailing '\n' is added + * to the message. + * arg: 0 to 2 arguments for printf(3) style substitution in message. + */ +#ifndef PNGDEBUG_H +#define PNGDEBUG_H +/* These settings control the formatting of messages in png.c and pngerror.c */ +/* Moved to pngdebug.h at 1.5.0 */ +# ifndef PNG_LITERAL_SHARP +# define PNG_LITERAL_SHARP 0x23 +# endif +# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET +# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b +# endif +# ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET +# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d +# endif +# ifndef PNG_STRING_NEWLINE +# define PNG_STRING_NEWLINE "\n" +# endif + +#ifdef PNG_DEBUG +# if (PNG_DEBUG > 0) +# if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER) +# include <crtdbg.h> +# if (PNG_DEBUG > 1) +# ifndef _DEBUG +# define _DEBUG +# endif +# ifndef png_debug +# define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2) +# endif +# endif +# else /* PNG_DEBUG_FILE || !_MSC_VER */ +# ifndef PNG_STDIO_SUPPORTED +# include <stdio.h> /* not included yet */ +# endif +# ifndef PNG_DEBUG_FILE +# define PNG_DEBUG_FILE stderr +# endif /* PNG_DEBUG_FILE */ + +# if (PNG_DEBUG > 1) +# ifdef __STDC__ +# ifndef png_debug +# define png_debug(l,m) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ + (num_tabs==2 ? " " : (num_tabs>2 ? " " : "")))); \ + } while (0) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ + (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1); \ + } while (0) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? " " : \ + (num_tabs==2 ? " " : (num_tabs>2 ? " " : ""))),p1,p2);\ + } while (0) +# endif +# else /* __STDC __ */ +# ifndef png_debug +# define png_debug(l,m) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format); \ + } while (0) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format,p1); \ + } while (0) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format,p1,p2); \ + } while (0) +# endif +# endif /* __STDC __ */ +# endif /* (PNG_DEBUG > 1) */ + +# endif /* _MSC_VER */ +# endif /* (PNG_DEBUG > 0) */ +#endif /* PNG_DEBUG */ +#ifndef png_debug +# define png_debug(l, m) ((void)0) +#endif +#ifndef png_debug1 +# define png_debug1(l, m, p1) ((void)0) +#endif +#ifndef png_debug2 +# define png_debug2(l, m, p1, p2) ((void)0) +#endif +#endif /* PNGDEBUG_H */ diff --git a/thirdparty/libpng/pngerror.c b/thirdparty/libpng/pngerror.c new file mode 100644 index 0000000000..3fc8092fa6 --- /dev/null +++ b/thirdparty/libpng/pngerror.c @@ -0,0 +1,963 @@ + +/* pngerror.c - stub functions for i/o and memory allocation + * + * Last changed in libpng 1.6.15 [November 20, 2014] + * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all error handling. Users who + * need special error handling are expected to write replacement functions + * and use png_set_error_fn() to use those functions. See the instructions + * at each function. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr, + png_const_charp error_message)),PNG_NORETURN); + +#ifdef PNG_WARNINGS_SUPPORTED +static void /* PRIVATE */ +png_default_warning PNGARG((png_const_structrp png_ptr, + png_const_charp warning_message)); +#endif /* WARNINGS */ + +/* This function is called whenever there is a fatal error. This function + * should not be changed. If there is a need to handle errors differently, + * you should supply a replacement error function and use png_set_error_fn() + * to replace the error function at run-time. + */ +#ifdef PNG_ERROR_TEXT_SUPPORTED +PNG_FUNCTION(void,PNGAPI +png_error,(png_const_structrp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + char msg[16]; + if (png_ptr != NULL) + { + if ((png_ptr->flags & + (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) + { + if (*error_message == PNG_LITERAL_SHARP) + { + /* Strip "#nnnn " from beginning of error message. */ + int offset; + for (offset = 1; offset<15; offset++) + if (error_message[offset] == ' ') + break; + + if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) + { + int i; + for (i = 0; i < offset - 1; i++) + msg[i] = error_message[i + 1]; + msg[i - 1] = '\0'; + error_message = msg; + } + + else + error_message += offset; + } + + else + { + if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0) + { + msg[0] = '0'; + msg[1] = '\0'; + error_message = msg; + } + } + } + } +#endif + if (png_ptr != NULL && png_ptr->error_fn != NULL) + (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), + error_message); + + /* If the custom handler doesn't exist, or if it returns, + use the default handler, which will not return. */ + png_default_error(png_ptr, error_message); +} +#else +PNG_FUNCTION(void,PNGAPI +png_err,(png_const_structrp png_ptr),PNG_NORETURN) +{ + /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed + * erroneously as '\0', instead of the empty string "". This was + * apparently an error, introduced in libpng-1.2.20, and png_default_error + * will crash in this case. + */ + if (png_ptr != NULL && png_ptr->error_fn != NULL) + (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), ""); + + /* If the custom handler doesn't exist, or if it returns, + use the default handler, which will not return. */ + png_default_error(png_ptr, ""); +} +#endif /* ERROR_TEXT */ + +/* Utility to safely appends strings to a buffer. This never errors out so + * error checking is not required in the caller. + */ +size_t +png_safecat(png_charp buffer, size_t bufsize, size_t pos, + png_const_charp string) +{ + if (buffer != NULL && pos < bufsize) + { + if (string != NULL) + while (*string != '\0' && pos < bufsize-1) + buffer[pos++] = *string++; + + buffer[pos] = '\0'; + } + + return pos; +} + +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) +/* Utility to dump an unsigned value into a buffer, given a start pointer and + * and end pointer (which should point just *beyond* the end of the buffer!) + * Returns the pointer to the start of the formatted string. + */ +png_charp +png_format_number(png_const_charp start, png_charp end, int format, + png_alloc_size_t number) +{ + int count = 0; /* number of digits output */ + int mincount = 1; /* minimum number required */ + int output = 0; /* digit output (for the fixed point format) */ + + *--end = '\0'; + + /* This is written so that the loop always runs at least once, even with + * number zero. + */ + while (end > start && (number != 0 || count < mincount)) + { + + static const char digits[] = "0123456789ABCDEF"; + + switch (format) + { + case PNG_NUMBER_FORMAT_fixed: + /* Needs five digits (the fraction) */ + mincount = 5; + if (output != 0 || number % 10 != 0) + { + *--end = digits[number % 10]; + output = 1; + } + number /= 10; + break; + + case PNG_NUMBER_FORMAT_02u: + /* Expects at least 2 digits. */ + mincount = 2; + /* FALL THROUGH */ + + case PNG_NUMBER_FORMAT_u: + *--end = digits[number % 10]; + number /= 10; + break; + + case PNG_NUMBER_FORMAT_02x: + /* This format expects at least two digits */ + mincount = 2; + /* FALL THROUGH */ + + case PNG_NUMBER_FORMAT_x: + *--end = digits[number & 0xf]; + number >>= 4; + break; + + default: /* an error */ + number = 0; + break; + } + + /* Keep track of the number of digits added */ + ++count; + + /* Float a fixed number here: */ + if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start)) + { + /* End of the fraction, but maybe nothing was output? In that case + * drop the decimal point. If the number is a true zero handle that + * here. + */ + if (output != 0) + *--end = '.'; + else if (number == 0) /* and !output */ + *--end = '0'; + } + } + + return end; +} +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* This function is called whenever there is a non-fatal error. This function + * should not be changed. If there is a need to handle warnings differently, + * you should supply a replacement warning function and use + * png_set_error_fn() to replace the warning function at run-time. + */ +void PNGAPI +png_warning(png_const_structrp png_ptr, png_const_charp warning_message) +{ + int offset = 0; + if (png_ptr != NULL) + { +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + if ((png_ptr->flags & + (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0) +#endif + { + if (*warning_message == PNG_LITERAL_SHARP) + { + for (offset = 1; offset < 15; offset++) + if (warning_message[offset] == ' ') + break; + } + } + } + if (png_ptr != NULL && png_ptr->warning_fn != NULL) + (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr), + warning_message + offset); + else + png_default_warning(png_ptr, warning_message + offset); +} + +/* These functions support 'formatted' warning messages with up to + * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter + * is introduced by @<number>, where 'number' starts at 1. This follows the + * standard established by X/Open for internationalizable error messages. + */ +void +png_warning_parameter(png_warning_parameters p, int number, + png_const_charp string) +{ + if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT) + (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string); +} + +void +png_warning_parameter_unsigned(png_warning_parameters p, int number, int format, + png_alloc_size_t value) +{ + char buffer[PNG_NUMBER_BUFFER_SIZE]; + png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value)); +} + +void +png_warning_parameter_signed(png_warning_parameters p, int number, int format, + png_int_32 value) +{ + png_alloc_size_t u; + png_charp str; + char buffer[PNG_NUMBER_BUFFER_SIZE]; + + /* Avoid overflow by doing the negate in a png_alloc_size_t: */ + u = (png_alloc_size_t)value; + if (value < 0) + u = ~u + 1; + + str = PNG_FORMAT_NUMBER(buffer, format, u); + + if (value < 0 && str > buffer) + *--str = '-'; + + png_warning_parameter(p, number, str); +} + +void +png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p, + png_const_charp message) +{ + /* The internal buffer is just 192 bytes - enough for all our messages, + * overflow doesn't happen because this code checks! If someone figures + * out how to send us a message longer than 192 bytes, all that will + * happen is that the message will be truncated appropriately. + */ + size_t i = 0; /* Index in the msg[] buffer: */ + char msg[192]; + + /* Each iteration through the following loop writes at most one character + * to msg[i++] then returns here to validate that there is still space for + * the trailing '\0'. It may (in the case of a parameter) read more than + * one character from message[]; it must check for '\0' and continue to the + * test if it finds the end of string. + */ + while (i<(sizeof msg)-1 && *message != '\0') + { + /* '@' at end of string is now just printed (previously it was skipped); + * it is an error in the calling code to terminate the string with @. + */ + if (p != NULL && *message == '@' && message[1] != '\0') + { + int parameter_char = *++message; /* Consume the '@' */ + static const char valid_parameters[] = "123456789"; + int parameter = 0; + + /* Search for the parameter digit, the index in the string is the + * parameter to use. + */ + while (valid_parameters[parameter] != parameter_char && + valid_parameters[parameter] != '\0') + ++parameter; + + /* If the parameter digit is out of range it will just get printed. */ + if (parameter < PNG_WARNING_PARAMETER_COUNT) + { + /* Append this parameter */ + png_const_charp parm = p[parameter]; + png_const_charp pend = p[parameter] + (sizeof p[parameter]); + + /* No need to copy the trailing '\0' here, but there is no guarantee + * that parm[] has been initialized, so there is no guarantee of a + * trailing '\0': + */ + while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend) + msg[i++] = *parm++; + + /* Consume the parameter digit too: */ + ++message; + continue; + } + + /* else not a parameter and there is a character after the @ sign; just + * copy that. This is known not to be '\0' because of the test above. + */ + } + + /* At this point *message can't be '\0', even in the bad parameter case + * above where there is a lone '@' at the end of the message string. + */ + msg[i++] = *message++; + } + + /* i is always less than (sizeof msg), so: */ + msg[i] = '\0'; + + /* And this is the formatted message. It may be larger than + * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these + * are not (currently) formatted. + */ + png_warning(png_ptr, msg); +} +#endif /* WARNINGS */ + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_benign_error(png_const_structrp png_ptr, png_const_charp error_message) +{ + if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) + { +# ifdef PNG_READ_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + png_ptr->chunk_name != 0) + png_chunk_warning(png_ptr, error_message); + else +# endif + png_warning(png_ptr, error_message); + } + + else + { +# ifdef PNG_READ_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + png_ptr->chunk_name != 0) + png_chunk_error(png_ptr, error_message); + else +# endif + png_error(png_ptr, error_message); + } + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} + +void /* PRIVATE */ +png_app_warning(png_const_structrp png_ptr, png_const_charp error_message) +{ + if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0) + png_warning(png_ptr, error_message); + else + png_error(png_ptr, error_message); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} + +void /* PRIVATE */ +png_app_error(png_const_structrp png_ptr, png_const_charp error_message) +{ + if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0) + png_warning(png_ptr, error_message); + else + png_error(png_ptr, error_message); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} +#endif /* BENIGN_ERRORS */ + +#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */ +#if defined(PNG_WARNINGS_SUPPORTED) || \ + (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)) +/* These utilities are used internally to build an error message that relates + * to the current chunk. The chunk name comes from png_ptr->chunk_name, + * which is used to prefix the message. The message is limited in length + * to 63 bytes. The name characters are output as hex digits wrapped in [] + * if the character is invalid. + */ +#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) +static PNG_CONST char png_digit[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', + 'A', 'B', 'C', 'D', 'E', 'F' +}; + +static void /* PRIVATE */ +png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp + error_message) +{ + png_uint_32 chunk_name = png_ptr->chunk_name; + int iout = 0, ishift = 24; + + while (ishift >= 0) + { + int c = (int)(chunk_name >> ishift) & 0xff; + + ishift -= 8; + if (isnonalpha(c) != 0) + { + buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET; + buffer[iout++] = png_digit[(c & 0xf0) >> 4]; + buffer[iout++] = png_digit[c & 0x0f]; + buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET; + } + + else + { + buffer[iout++] = (char)c; + } + } + + if (error_message == NULL) + buffer[iout] = '\0'; + + else + { + int iin = 0; + + buffer[iout++] = ':'; + buffer[iout++] = ' '; + + while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0') + buffer[iout++] = error_message[iin++]; + + /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */ + buffer[iout] = '\0'; + } +} +#endif /* WARNINGS || ERROR_TEXT */ + +#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) +PNG_FUNCTION(void,PNGAPI +png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ + char msg[18+PNG_MAX_ERROR_TEXT]; + if (png_ptr == NULL) + png_error(png_ptr, error_message); + + else + { + png_format_buffer(png_ptr, msg, error_message); + png_error(png_ptr, msg); + } +} +#endif /* READ && ERROR_TEXT */ + +#ifdef PNG_WARNINGS_SUPPORTED +void PNGAPI +png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message) +{ + char msg[18+PNG_MAX_ERROR_TEXT]; + if (png_ptr == NULL) + png_warning(png_ptr, warning_message); + + else + { + png_format_buffer(png_ptr, msg, warning_message); + png_warning(png_ptr, msg); + } +} +#endif /* WARNINGS */ + +#ifdef PNG_READ_SUPPORTED +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp + error_message) +{ + if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0) + png_chunk_warning(png_ptr, error_message); + + else + png_chunk_error(png_ptr, error_message); + +# ifndef PNG_ERROR_TEXT_SUPPORTED + PNG_UNUSED(error_message) +# endif +} +#endif +#endif /* READ */ + +void /* PRIVATE */ +png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error) +{ +# ifndef PNG_WARNINGS_SUPPORTED + PNG_UNUSED(message) +# endif + + /* This is always supported, but for just read or just write it + * unconditionally does the right thing. + */ +# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) +# endif + +# ifdef PNG_READ_SUPPORTED + { + if (error < PNG_CHUNK_ERROR) + png_chunk_warning(png_ptr, message); + + else + png_chunk_benign_error(png_ptr, message); + } +# endif + +# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED) + else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) +# endif + +# ifdef PNG_WRITE_SUPPORTED + { + if (error < PNG_CHUNK_WRITE_ERROR) + png_app_warning(png_ptr, message); + + else + png_app_error(png_ptr, message); + } +# endif +} + +#ifdef PNG_ERROR_TEXT_SUPPORTED +#ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_FUNCTION(void, +png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN) +{ +# define fixed_message "fixed point overflow in " +# define fixed_message_ln ((sizeof fixed_message)-1) + int iin; + char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT]; + memcpy(msg, fixed_message, fixed_message_ln); + iin = 0; + if (name != NULL) + while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0) + { + msg[fixed_message_ln + iin] = name[iin]; + ++iin; + } + msg[fixed_message_ln + iin] = 0; + png_error(png_ptr, msg); +} +#endif +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* This API only exists if ANSI-C style error handling is used, + * otherwise it is necessary for png_default_error to be overridden. + */ +jmp_buf* PNGAPI +png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn, + size_t jmp_buf_size) +{ + /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value + * and it must not change after that. Libpng doesn't care how big the + * buffer is, just that it doesn't change. + * + * If the buffer size is no *larger* than the size of jmp_buf when libpng is + * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0 + * semantics that this call will not fail. If the size is larger, however, + * the buffer is allocated and this may fail, causing the function to return + * NULL. + */ + if (png_ptr == NULL) + return NULL; + + if (png_ptr->jmp_buf_ptr == NULL) + { + png_ptr->jmp_buf_size = 0; /* not allocated */ + + if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local)) + png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; + + else + { + png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *, + png_malloc_warn(png_ptr, jmp_buf_size)); + + if (png_ptr->jmp_buf_ptr == NULL) + return NULL; /* new NULL return on OOM */ + + png_ptr->jmp_buf_size = jmp_buf_size; + } + } + + else /* Already allocated: check the size */ + { + size_t size = png_ptr->jmp_buf_size; + + if (size == 0) + { + size = (sizeof png_ptr->jmp_buf_local); + if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local) + { + /* This is an internal error in libpng: somehow we have been left + * with a stack allocated jmp_buf when the application regained + * control. It's always possible to fix this up, but for the moment + * this is a png_error because that makes it easy to detect. + */ + png_error(png_ptr, "Libpng jmp_buf still allocated"); + /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */ + } + } + + if (size != jmp_buf_size) + { + png_warning(png_ptr, "Application jmp_buf size changed"); + return NULL; /* caller will probably crash: no choice here */ + } + } + + /* Finally fill in the function, now we have a satisfactory buffer. It is + * valid to change the function on every call. + */ + png_ptr->longjmp_fn = longjmp_fn; + return png_ptr->jmp_buf_ptr; +} + +void /* PRIVATE */ +png_free_jmpbuf(png_structrp png_ptr) +{ + if (png_ptr != NULL) + { + jmp_buf *jb = png_ptr->jmp_buf_ptr; + + /* A size of 0 is used to indicate a local, stack, allocation of the + * pointer; used here and in png.c + */ + if (jb != NULL && png_ptr->jmp_buf_size > 0) + { + + /* This stuff is so that a failure to free the error control structure + * does not leave libpng in a state with no valid error handling: the + * free always succeeds, if there is an error it gets ignored. + */ + if (jb != &png_ptr->jmp_buf_local) + { + /* Make an internal, libpng, jmp_buf to return here */ + jmp_buf free_jmp_buf; + + if (!setjmp(free_jmp_buf)) + { + png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */ + png_ptr->jmp_buf_size = 0; /* stack allocation */ + png_ptr->longjmp_fn = longjmp; + png_free(png_ptr, jb); /* Return to setjmp on error */ + } + } + } + + /* *Always* cancel everything out: */ + png_ptr->jmp_buf_size = 0; + png_ptr->jmp_buf_ptr = NULL; + png_ptr->longjmp_fn = 0; + } +} +#endif + +/* This is the default error handling function. Note that replacements for + * this function MUST NOT RETURN, or the program will likely crash. This + * function is used by default, or if the program supplies NULL for the + * error function pointer in png_set_error_fn(). + */ +static PNG_FUNCTION(void /* PRIVATE */, +png_default_error,(png_const_structrp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ +#ifdef PNG_CONSOLE_IO_SUPPORTED +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + /* Check on NULL only added in 1.5.4 */ + if (error_message != NULL && *error_message == PNG_LITERAL_SHARP) + { + /* Strip "#nnnn " from beginning of error message. */ + int offset; + char error_number[16]; + for (offset = 0; offset<15; offset++) + { + error_number[offset] = error_message[offset + 1]; + if (error_message[offset] == ' ') + break; + } + + if ((offset > 1) && (offset < 15)) + { + error_number[offset - 1] = '\0'; + fprintf(stderr, "libpng error no. %s: %s", + error_number, error_message + offset + 1); + fprintf(stderr, PNG_STRING_NEWLINE); + } + + else + { + fprintf(stderr, "libpng error: %s, offset=%d", + error_message, offset); + fprintf(stderr, PNG_STRING_NEWLINE); + } + } + else +#endif + { + fprintf(stderr, "libpng error: %s", error_message ? error_message : + "undefined"); + fprintf(stderr, PNG_STRING_NEWLINE); + } +#else + PNG_UNUSED(error_message) /* Make compiler happy */ +#endif + png_longjmp(png_ptr, 1); +} + +PNG_FUNCTION(void,PNGAPI +png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN) +{ +#ifdef PNG_SETJMP_SUPPORTED + if (png_ptr != NULL && png_ptr->longjmp_fn != NULL && + png_ptr->jmp_buf_ptr != NULL) + png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val); +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(val) +#endif + + /* If control reaches this point, png_longjmp() must not return. The only + * choice is to terminate the whole process (or maybe the thread); to do + * this the ANSI-C abort() function is used unless a different method is + * implemented by overriding the default configuration setting for + * PNG_ABORT(). + */ + PNG_ABORT(); +} + +#ifdef PNG_WARNINGS_SUPPORTED +/* This function is called when there is a warning, but the library thinks + * it can continue anyway. Replacement functions don't have to do anything + * here if you don't want them to. In the default configuration, png_ptr is + * not used, but it is passed in case it may be useful. + */ +static void /* PRIVATE */ +png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message) +{ +#ifdef PNG_CONSOLE_IO_SUPPORTED +# ifdef PNG_ERROR_NUMBERS_SUPPORTED + if (*warning_message == PNG_LITERAL_SHARP) + { + int offset; + char warning_number[16]; + for (offset = 0; offset < 15; offset++) + { + warning_number[offset] = warning_message[offset + 1]; + if (warning_message[offset] == ' ') + break; + } + + if ((offset > 1) && (offset < 15)) + { + warning_number[offset + 1] = '\0'; + fprintf(stderr, "libpng warning no. %s: %s", + warning_number, warning_message + offset); + fprintf(stderr, PNG_STRING_NEWLINE); + } + + else + { + fprintf(stderr, "libpng warning: %s", + warning_message); + fprintf(stderr, PNG_STRING_NEWLINE); + } + } + else +# endif + + { + fprintf(stderr, "libpng warning: %s", warning_message); + fprintf(stderr, PNG_STRING_NEWLINE); + } +#else + PNG_UNUSED(warning_message) /* Make compiler happy */ +#endif + PNG_UNUSED(png_ptr) /* Make compiler happy */ +} +#endif /* WARNINGS */ + +/* This function is called when the application wants to use another method + * of handling errors and warnings. Note that the error function MUST NOT + * return to the calling routine or serious problems will occur. The return + * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1) + */ +void PNGAPI +png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warning_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->error_ptr = error_ptr; + png_ptr->error_fn = error_fn; +#ifdef PNG_WARNINGS_SUPPORTED + png_ptr->warning_fn = warning_fn; +#else + PNG_UNUSED(warning_fn) +#endif +} + + +/* This function returns a pointer to the error_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp PNGAPI +png_get_error_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return NULL; + + return ((png_voidp)png_ptr->error_ptr); +} + + +#ifdef PNG_ERROR_NUMBERS_SUPPORTED +void PNGAPI +png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode) +{ + if (png_ptr != NULL) + { + png_ptr->flags &= + ((~(PNG_FLAG_STRIP_ERROR_NUMBERS | + PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); + } +} +#endif + +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) + /* Currently the above both depend on SETJMP_SUPPORTED, however it would be + * possible to implement without setjmp support just so long as there is some + * way to handle the error return here: + */ +PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI +png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message), + PNG_NORETURN) +{ + const png_const_structrp png_ptr = png_nonconst_ptr; + png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); + + /* An error is always logged here, overwriting anything (typically a warning) + * that is already there: + */ + if (image != NULL) + { + png_safecat(image->message, (sizeof image->message), 0, error_message); + image->warning_or_error |= PNG_IMAGE_ERROR; + + /* Retrieve the jmp_buf from within the png_control, making this work for + * C++ compilation too is pretty tricky: C++ wants a pointer to the first + * element of a jmp_buf, but C doesn't tell us the type of that. + */ + if (image->opaque != NULL && image->opaque->error_buf != NULL) + longjmp(png_control_jmp_buf(image->opaque), 1); + + /* Missing longjmp buffer, the following is to help debugging: */ + { + size_t pos = png_safecat(image->message, (sizeof image->message), 0, + "bad longjmp: "); + png_safecat(image->message, (sizeof image->message), pos, + error_message); + } + } + + /* Here on an internal programming error. */ + abort(); +} + +#ifdef PNG_WARNINGS_SUPPORTED +void /* PRIVATE */ PNGCBAPI +png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message) +{ + const png_const_structrp png_ptr = png_nonconst_ptr; + png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr); + + /* A warning is only logged if there is no prior warning or error. */ + if (image->warning_or_error == 0) + { + png_safecat(image->message, (sizeof image->message), 0, warning_message); + image->warning_or_error |= PNG_IMAGE_WARNING; + } +} +#endif + +int /* PRIVATE */ +png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg) +{ + volatile png_imagep image = image_in; + volatile int result; + volatile png_voidp saved_error_buf; + jmp_buf safe_jmpbuf; + + /* Safely execute function(arg) with png_error returning to this function. */ + saved_error_buf = image->opaque->error_buf; + result = setjmp(safe_jmpbuf) == 0; + + if (result != 0) + { + + image->opaque->error_buf = safe_jmpbuf; + result = function(arg); + } + + image->opaque->error_buf = saved_error_buf; + + /* And do the cleanup prior to any failure return. */ + if (result == 0) + png_image_free(image); + + return result; +} +#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */ +#endif /* READ || WRITE */ diff --git a/thirdparty/libpng/pngget.c b/thirdparty/libpng/pngget.c new file mode 100644 index 0000000000..14fc7be520 --- /dev/null +++ b/thirdparty/libpng/pngget.c @@ -0,0 +1,1219 @@ + +/* pngget.c - retrieval of values from info struct + * + * Last changed in libpng 1.6.17 [March 26, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +png_uint_32 PNGAPI +png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 flag) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->valid & flag); + + return(0); +} + +png_size_t PNGAPI +png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->rowbytes); + + return(0); +} + +#ifdef PNG_INFO_IMAGE_SUPPORTED +png_bytepp PNGAPI +png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->row_pointers); + + return(0); +} +#endif + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Easy access to info, added in libpng-0.99 */ +png_uint_32 PNGAPI +png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->width; + + return (0); +} + +png_uint_32 PNGAPI +png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->height; + + return (0); +} + +png_byte PNGAPI +png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->bit_depth; + + return (0); +} + +png_byte PNGAPI +png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->color_type; + + return (0); +} + +png_byte PNGAPI +png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->filter_type; + + return (0); +} + +png_byte PNGAPI +png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->interlace_type; + + return (0); +} + +png_byte PNGAPI +png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->compression_type; + + return (0); +} + +png_uint_32 PNGAPI +png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp + info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", + "png_get_x_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) + return (info_ptr->x_pixels_per_unit); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_uint_32 PNGAPI +png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp + info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", + "png_get_y_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) + return (info_ptr->y_pixels_per_unit); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_uint_32 PNGAPI +png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER && + info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit) + return (info_ptr->x_pixels_per_unit); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp + info_ptr) +{ +#ifdef PNG_READ_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio"); + + if (info_ptr->x_pixels_per_unit != 0) + return ((float)((float)info_ptr->y_pixels_per_unit + /(float)info_ptr->x_pixels_per_unit)); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return ((float)0.0); +} +#endif + +#ifdef PNG_FIXED_POINT_SUPPORTED +png_fixed_point PNGAPI +png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr, + png_const_inforp info_ptr) +{ +#ifdef PNG_READ_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0 && + info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 && + info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX && + info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX) + { + png_fixed_point res; + + png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed"); + + /* The following casts work because a PNG 4 byte integer only has a valid + * range of 0..2^31-1; otherwise the cast might overflow. + */ + if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1, + (png_int_32)info_ptr->x_pixels_per_unit) != 0) + return res; + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return 0; +} +#endif + +png_int_32 PNGAPI +png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) + return (info_ptr->x_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) + return (info_ptr->y_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) + return (info_ptr->x_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) + return (info_ptr->y_offset); + } +#else + PNG_UNUSED(png_ptr) + PNG_UNUSED(info_ptr) +#endif + + return (0); +} + +#ifdef PNG_INCH_CONVERSIONS_SUPPORTED +static png_uint_32 +ppi_from_ppm(png_uint_32 ppm) +{ +#if 0 + /* The conversion is *(2.54/100), in binary (32 digits): + * .00000110100000001001110101001001 + */ + png_uint_32 t1001, t1101; + ppm >>= 1; /* .1 */ + t1001 = ppm + (ppm >> 3); /* .1001 */ + t1101 = t1001 + (ppm >> 1); /* .1101 */ + ppm >>= 20; /* .000000000000000000001 */ + t1101 += t1101 >> 15; /* .1101000000000001101 */ + t1001 >>= 11; /* .000000000001001 */ + t1001 += t1001 >> 12; /* .000000000001001000000001001 */ + ppm += t1001; /* .000000000001001000001001001 */ + ppm += t1101; /* .110100000001001110101001001 */ + return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */ +#else + /* The argument is a PNG unsigned integer, so it is not permitted + * to be bigger than 2^31. + */ + png_fixed_point result; + if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127, + 5000) != 0) + return result; + + /* Overflow. */ + return 0; +#endif +} + +png_uint_32 PNGAPI +png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr)); +} + +png_uint_32 PNGAPI +png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr)); +} + +png_uint_32 PNGAPI +png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr)); +} + +#ifdef PNG_FIXED_POINT_SUPPORTED +static png_fixed_point +png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns) +{ + /* Convert from metres * 1,000,000 to inches * 100,000, meters to + * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127. + * Notice that this can overflow - a warning is output and 0 is + * returned. + */ + return png_muldiv_warn(png_ptr, microns, 500, 127); +} + +png_fixed_point PNGAPI +png_get_x_offset_inches_fixed(png_const_structrp png_ptr, + png_const_inforp info_ptr) +{ + return png_fixed_inches_from_microns(png_ptr, + png_get_x_offset_microns(png_ptr, info_ptr)); +} +#endif + +#ifdef PNG_FIXED_POINT_SUPPORTED +png_fixed_point PNGAPI +png_get_y_offset_inches_fixed(png_const_structrp png_ptr, + png_const_inforp info_ptr) +{ + return png_fixed_inches_from_microns(png_ptr, + png_get_y_offset_microns(png_ptr, info_ptr)); +} +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + /* To avoid the overflow do the conversion directly in floating + * point. + */ + return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937); +} +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + /* To avoid the overflow do the conversion directly in floating + * point. + */ + return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937); +} +#endif + +#ifdef PNG_pHYs_SUPPORTED +png_uint_32 PNGAPI +png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_debug1(1, "in %s retrieval function", "pHYs"); + + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + + if (*unit_type == 1) + { + if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50); + if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50); + } + } + } + + return (retval); +} +#endif /* pHYs */ +#endif /* INCH_CONVERSIONS */ + +/* png_get_channels really belongs in here, too, but it's been around longer */ + +#endif /* EASY_ACCESS */ + + +png_byte PNGAPI +png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->channels); + + return (0); +} + +#ifdef PNG_READ_SUPPORTED +png_const_bytep PNGAPI +png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->signature); + + return (NULL); +} +#endif + +#ifdef PNG_bKGD_SUPPORTED +png_uint_32 PNGAPI +png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, + png_color_16p *background) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_bKGD) != 0 && + background != NULL) + { + png_debug1(1, "in %s retrieval function", "bKGD"); + + *background = &(info_ptr->background); + return (PNG_INFO_bKGD); + } + + return (0); +} +#endif + +#ifdef PNG_cHRM_SUPPORTED +/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the + * same time to correct the rgb grayscale coefficient defaults obtained from the + * cHRM chunk in 1.5.4 + */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr, + double *white_x, double *white_y, double *red_x, double *red_y, + double *green_x, double *green_y, double *blue_x, double *blue_y) +{ + /* Quiet API change: this code used to only return the end points if a cHRM + * chunk was present, but the end points can also come from iCCP or sRGB + * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and + * the png_set_ APIs merely check that set end points are mutually + * consistent. + */ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + png_debug1(1, "in %s retrieval function", "cHRM"); + + if (white_x != NULL) + *white_x = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.whitex, "cHRM white X"); + if (white_y != NULL) + *white_y = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y"); + if (red_x != NULL) + *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx, + "cHRM red X"); + if (red_y != NULL) + *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy, + "cHRM red Y"); + if (green_x != NULL) + *green_x = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.greenx, "cHRM green X"); + if (green_y != NULL) + *green_y = png_float(png_ptr, + info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y"); + if (blue_x != NULL) + *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex, + "cHRM blue X"); + if (blue_y != NULL) + *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey, + "cHRM blue Y"); + return (PNG_INFO_cHRM); + } + + return (0); +} + +png_uint_32 PNGAPI +png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr, + double *red_X, double *red_Y, double *red_Z, double *green_X, + double *green_Y, double *green_Z, double *blue_X, double *blue_Y, + double *blue_Z) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)"); + + if (red_X != NULL) + *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X, + "cHRM red X"); + if (red_Y != NULL) + *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y, + "cHRM red Y"); + if (red_Z != NULL) + *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z, + "cHRM red Z"); + if (green_X != NULL) + *green_X = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X"); + if (green_Y != NULL) + *green_Y = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y"); + if (green_Z != NULL) + *green_Z = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z"); + if (blue_X != NULL) + *blue_X = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X"); + if (blue_Y != NULL) + *blue_Y = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y"); + if (blue_Z != NULL) + *blue_Z = png_float(png_ptr, + info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z"); + return (PNG_INFO_cHRM); + } + + return (0); +} +# endif + +# ifdef PNG_FIXED_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *int_red_X, png_fixed_point *int_red_Y, + png_fixed_point *int_red_Z, png_fixed_point *int_green_X, + png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, + png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, + png_fixed_point *int_blue_Z) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + png_debug1(1, "in %s retrieval function", "cHRM_XYZ"); + + if (int_red_X != NULL) + *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X; + if (int_red_Y != NULL) + *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y; + if (int_red_Z != NULL) + *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z; + if (int_green_X != NULL) + *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X; + if (int_green_Y != NULL) + *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y; + if (int_green_Z != NULL) + *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z; + if (int_blue_X != NULL) + *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X; + if (int_blue_Y != NULL) + *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y; + if (int_blue_Z != NULL) + *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z; + return (PNG_INFO_cHRM); + } + + return (0); +} + +png_uint_32 PNGAPI +png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x, + png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y, + png_fixed_point *blue_x, png_fixed_point *blue_y) +{ + png_debug1(1, "in %s retrieval function", "cHRM"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0) + { + if (white_x != NULL) + *white_x = info_ptr->colorspace.end_points_xy.whitex; + if (white_y != NULL) + *white_y = info_ptr->colorspace.end_points_xy.whitey; + if (red_x != NULL) + *red_x = info_ptr->colorspace.end_points_xy.redx; + if (red_y != NULL) + *red_y = info_ptr->colorspace.end_points_xy.redy; + if (green_x != NULL) + *green_x = info_ptr->colorspace.end_points_xy.greenx; + if (green_y != NULL) + *green_y = info_ptr->colorspace.end_points_xy.greeny; + if (blue_x != NULL) + *blue_x = info_ptr->colorspace.end_points_xy.bluex; + if (blue_y != NULL) + *blue_y = info_ptr->colorspace.end_points_xy.bluey; + return (PNG_INFO_cHRM); + } + + return (0); +} +# endif +#endif + +#ifdef PNG_gAMA_SUPPORTED +# ifdef PNG_FIXED_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_fixed_point *file_gamma) +{ + png_debug1(1, "in %s retrieval function", "gAMA"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && + file_gamma != NULL) + { + *file_gamma = info_ptr->colorspace.gamma; + return (PNG_INFO_gAMA); + } + + return (0); +} +# endif + +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr, + double *file_gamma) +{ + png_debug1(1, "in %s retrieval function", "gAMA(float)"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 && + file_gamma != NULL) + { + *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma, + "png_get_gAMA"); + return (PNG_INFO_gAMA); + } + + return (0); +} +# endif +#endif + +#ifdef PNG_sRGB_SUPPORTED +png_uint_32 PNGAPI +png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *file_srgb_intent) +{ + png_debug1(1, "in %s retrieval function", "sRGB"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL) + { + *file_srgb_intent = info_ptr->colorspace.rendering_intent; + return (PNG_INFO_sRGB); + } + + return (0); +} +#endif + +#ifdef PNG_iCCP_SUPPORTED +png_uint_32 PNGAPI +png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, + png_charpp name, int *compression_type, + png_bytepp profile, png_uint_32 *proflen) +{ + png_debug1(1, "in %s retrieval function", "iCCP"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_iCCP) != 0 && + name != NULL && compression_type != NULL && profile != NULL && + proflen != NULL) + { + *name = info_ptr->iccp_name; + *profile = info_ptr->iccp_profile; + *proflen = png_get_uint_32(info_ptr->iccp_profile); + /* This is somewhat irrelevant since the profile data returned has + * actually been uncompressed. + */ + *compression_type = PNG_COMPRESSION_TYPE_BASE; + return (PNG_INFO_iCCP); + } + + return (0); +} +#endif + +#ifdef PNG_sPLT_SUPPORTED +int PNGAPI +png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr, + png_sPLT_tpp spalettes) +{ + if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL) + { + *spalettes = info_ptr->splt_palettes; + return info_ptr->splt_palettes_num; + } + + return (0); +} +#endif + +#ifdef PNG_hIST_SUPPORTED +png_uint_32 PNGAPI +png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr, + png_uint_16p *hist) +{ + png_debug1(1, "in %s retrieval function", "hIST"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL) + { + *hist = info_ptr->hist; + return (PNG_INFO_hIST); + } + + return (0); +} +#endif + +png_uint_32 PNGAPI +png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 *width, png_uint_32 *height, int *bit_depth, + int *color_type, int *interlace_type, int *compression_type, + int *filter_type) +{ + png_debug1(1, "in %s retrieval function", "IHDR"); + + if (png_ptr == NULL || info_ptr == NULL) + return (0); + + if (width != NULL) + *width = info_ptr->width; + + if (height != NULL) + *height = info_ptr->height; + + if (bit_depth != NULL) + *bit_depth = info_ptr->bit_depth; + + if (color_type != NULL) + *color_type = info_ptr->color_type; + + if (compression_type != NULL) + *compression_type = info_ptr->compression_type; + + if (filter_type != NULL) + *filter_type = info_ptr->filter_type; + + if (interlace_type != NULL) + *interlace_type = info_ptr->interlace_type; + + /* This is redundant if we can be sure that the info_ptr values were all + * assigned in png_set_IHDR(). We do the check anyhow in case an + * application has ignored our advice not to mess with the members + * of info_ptr directly. + */ + png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, + info_ptr->compression_type, info_ptr->filter_type); + + return (1); +} + +#ifdef PNG_oFFs_SUPPORTED +png_uint_32 PNGAPI +png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type) +{ + png_debug1(1, "in %s retrieval function", "oFFs"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_oFFs) != 0 && + offset_x != NULL && offset_y != NULL && unit_type != NULL) + { + *offset_x = info_ptr->x_offset; + *offset_y = info_ptr->y_offset; + *unit_type = (int)info_ptr->offset_unit_type; + return (PNG_INFO_oFFs); + } + + return (0); +} +#endif + +#ifdef PNG_pCAL_SUPPORTED +png_uint_32 PNGAPI +png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, + png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, + png_charp *units, png_charpp *params) +{ + png_debug1(1, "in %s retrieval function", "pCAL"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pCAL) != 0 && + purpose != NULL && X0 != NULL && X1 != NULL && type != NULL && + nparams != NULL && units != NULL && params != NULL) + { + *purpose = info_ptr->pcal_purpose; + *X0 = info_ptr->pcal_X0; + *X1 = info_ptr->pcal_X1; + *type = (int)info_ptr->pcal_type; + *nparams = (int)info_ptr->pcal_nparams; + *units = info_ptr->pcal_units; + *params = info_ptr->pcal_params; + return (PNG_INFO_pCAL); + } + + return (0); +} +#endif + +#ifdef PNG_sCAL_SUPPORTED +# ifdef PNG_FIXED_POINT_SUPPORTED +# if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \ + defined(PNG_FLOATING_POINT_SUPPORTED) +png_uint_32 PNGAPI +png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *unit, png_fixed_point *width, png_fixed_point *height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + *unit = info_ptr->scal_unit; + /*TODO: make this work without FP support; the API is currently eliminated + * if neither floating point APIs nor internal floating point arithmetic + * are enabled. + */ + *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width"); + *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height), + "sCAL height"); + return (PNG_INFO_sCAL); + } + + return(0); +} +# endif /* FLOATING_ARITHMETIC */ +# endif /* FIXED_POINT */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *unit, double *width, double *height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + *unit = info_ptr->scal_unit; + *width = atof(info_ptr->scal_s_width); + *height = atof(info_ptr->scal_s_height); + return (PNG_INFO_sCAL); + } + + return(0); +} +# endif /* FLOATING POINT */ +png_uint_32 PNGAPI +png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr, + int *unit, png_charpp width, png_charpp height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + *unit = info_ptr->scal_unit; + *width = info_ptr->scal_s_width; + *height = info_ptr->scal_s_height; + return (PNG_INFO_sCAL); + } + + return(0); +} +#endif /* sCAL */ + +#ifdef PNG_pHYs_SUPPORTED +png_uint_32 PNGAPI +png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + png_debug1(1, "in %s retrieval function", "pHYs"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + } + } + + return (retval); +} +#endif /* pHYs */ + +png_uint_32 PNGAPI +png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr, + png_colorp *palette, int *num_palette) +{ + png_debug1(1, "in %s retrieval function", "PLTE"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL) + { + *palette = info_ptr->palette; + *num_palette = info_ptr->num_palette; + png_debug1(3, "num_palette = %d", *num_palette); + return (PNG_INFO_PLTE); + } + + return (0); +} + +#ifdef PNG_sBIT_SUPPORTED +png_uint_32 PNGAPI +png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, + png_color_8p *sig_bit) +{ + png_debug1(1, "in %s retrieval function", "sBIT"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL) + { + *sig_bit = &(info_ptr->sig_bit); + return (PNG_INFO_sBIT); + } + + return (0); +} +#endif + +#ifdef PNG_TEXT_SUPPORTED +int PNGAPI +png_get_text(png_const_structrp png_ptr, png_inforp info_ptr, + png_textp *text_ptr, int *num_text) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0) + { + png_debug1(1, "in 0x%lx retrieval function", + (unsigned long)png_ptr->chunk_name); + + if (text_ptr != NULL) + *text_ptr = info_ptr->text; + + if (num_text != NULL) + *num_text = info_ptr->num_text; + + return info_ptr->num_text; + } + + if (num_text != NULL) + *num_text = 0; + + return(0); +} +#endif + +#ifdef PNG_tIME_SUPPORTED +png_uint_32 PNGAPI +png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr, + png_timep *mod_time) +{ + png_debug1(1, "in %s retrieval function", "tIME"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL) + { + *mod_time = &(info_ptr->mod_time); + return (PNG_INFO_tIME); + } + + return (0); +} +#endif + +#ifdef PNG_tRNS_SUPPORTED +png_uint_32 PNGAPI +png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr, + png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color) +{ + png_uint_32 retval = 0; + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_tRNS) != 0) + { + png_debug1(1, "in %s retrieval function", "tRNS"); + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (trans_alpha != NULL) + { + *trans_alpha = info_ptr->trans_alpha; + retval |= PNG_INFO_tRNS; + } + + if (trans_color != NULL) + *trans_color = &(info_ptr->trans_color); + } + + else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */ + { + if (trans_color != NULL) + { + *trans_color = &(info_ptr->trans_color); + retval |= PNG_INFO_tRNS; + } + + if (trans_alpha != NULL) + *trans_alpha = NULL; + } + + if (num_trans != NULL) + { + *num_trans = info_ptr->num_trans; + retval |= PNG_INFO_tRNS; + } + } + + return (retval); +} +#endif + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +int PNGAPI +png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr, + png_unknown_chunkpp unknowns) +{ + if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL) + { + *unknowns = info_ptr->unknown_chunks; + return info_ptr->unknown_chunks_num; + } + + return (0); +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +png_byte PNGAPI +png_get_rgb_to_gray_status (png_const_structrp png_ptr) +{ + return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0); +} +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +png_voidp PNGAPI +png_get_user_chunk_ptr(png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_ptr : NULL); +} +#endif + +png_size_t PNGAPI +png_get_compression_buffer_size(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return 0; + +#ifdef PNG_WRITE_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) +#endif + { +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED + return png_ptr->IDAT_read_size; +#else + return PNG_IDAT_READ_SIZE; +#endif + } + +#ifdef PNG_WRITE_SUPPORTED + else + return png_ptr->zbuffer_size; +#endif +} + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +/* These functions were added to libpng 1.2.6 and were enabled + * by default in libpng-1.4.0 */ +png_uint_32 PNGAPI +png_get_user_width_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_width_max : 0); +} + +png_uint_32 PNGAPI +png_get_user_height_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_height_max : 0); +} + +/* This function was added to libpng 1.4.0 */ +png_uint_32 PNGAPI +png_get_chunk_cache_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_cache_max : 0); +} + +/* This function was added to libpng 1.4.1 */ +png_alloc_size_t PNGAPI +png_get_chunk_malloc_max (png_const_structrp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_malloc_max : 0); +} +#endif /* SET_USER_LIMITS */ + +/* These functions were added to libpng 1.4.0 */ +#ifdef PNG_IO_STATE_SUPPORTED +png_uint_32 PNGAPI +png_get_io_state (png_const_structrp png_ptr) +{ + return png_ptr->io_state; +} + +png_uint_32 PNGAPI +png_get_io_chunk_type (png_const_structrp png_ptr) +{ + return png_ptr->chunk_name; +} +#endif /* IO_STATE */ + +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED +# ifdef PNG_GET_PALETTE_MAX_SUPPORTED +int PNGAPI +png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return png_ptr->num_palette_max; + + return (-1); +} +# endif +#endif + +#endif /* READ || WRITE */ diff --git a/thirdparty/libpng/pnginfo.h b/thirdparty/libpng/pnginfo.h new file mode 100644 index 0000000000..361ed8be70 --- /dev/null +++ b/thirdparty/libpng/pnginfo.h @@ -0,0 +1,259 @@ + +/* pnginfo.h - header file for PNG reference library + * + * Last changed in libpng 1.6.1 [March 28, 2013] + * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + + /* png_info is a structure that holds the information in a PNG file so + * that the application can find out the characteristics of the image. + * If you are reading the file, this structure will tell you what is + * in the PNG file. If you are writing the file, fill in the information + * you want to put into the PNG file, using png_set_*() functions, then + * call png_write_info(). + * + * The names chosen should be very close to the PNG specification, so + * consult that document for information about the meaning of each field. + * + * With libpng < 0.95, it was only possible to directly set and read the + * the values in the png_info_struct, which meant that the contents and + * order of the values had to remain fixed. With libpng 0.95 and later, + * however, there are now functions that abstract the contents of + * png_info_struct from the application, so this makes it easier to use + * libpng with dynamic libraries, and even makes it possible to use + * libraries that don't have all of the libpng ancillary chunk-handing + * functionality. In libpng-1.5.0 this was moved into a separate private + * file that is not visible to applications. + * + * The following members may have allocated storage attached that should be + * cleaned up before the structure is discarded: palette, trans, text, + * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile, + * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these + * are automatically freed when the info structure is deallocated, if they were + * allocated internally by libpng. This behavior can be changed by means + * of the png_data_freer() function. + * + * More allocation details: all the chunk-reading functions that + * change these members go through the corresponding png_set_* + * functions. A function to clear these members is available: see + * png_free_data(). The png_set_* functions do not depend on being + * able to point info structure members to any of the storage they are + * passed (they make their own copies), EXCEPT that the png_set_text + * functions use the same storage passed to them in the text_ptr or + * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns + * functions do not make their own copies. + */ +#ifndef PNGINFO_H +#define PNGINFO_H + +struct png_info_def +{ + /* The following are necessary for every PNG file */ + png_uint_32 width; /* width of image in pixels (from IHDR) */ + png_uint_32 height; /* height of image in pixels (from IHDR) */ + png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */ + png_size_t rowbytes; /* bytes needed to hold an untransformed row */ + png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */ + png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */ + png_uint_16 num_trans; /* number of transparent palette color (tRNS) */ + png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */ + png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */ + /* The following three should have been named *_method not *_type */ + png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */ + png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */ + png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + + /* The following are set by png_set_IHDR, called from the application on + * write, but the are never actually used by the write code. + */ + png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte spare_byte; /* to align the data, and for future use */ + +#ifdef PNG_READ_SUPPORTED + /* This is never set during write */ + png_byte signature[8]; /* magic bytes read by libpng from start of file */ +#endif + + /* The rest of the data is optional. If you are reading, check the + * valid field to see if the information in these are valid. If you + * are writing, set the valid field to those chunks you want written, + * and initialize the appropriate fields below. + */ + +#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) + /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are + * defined. When COLORSPACE is switched on all the colorspace-defining + * chunks should be enabled, when GAMMA is switched on all the gamma-defining + * chunks should be enabled. If this is not done it becomes possible to read + * inconsistent PNG files and assign a probably incorrect interpretation to + * the information. (In other words, by carefully choosing which chunks to + * recognize the system configuration can select an interpretation for PNG + * files containing ambiguous data and this will result in inconsistent + * behavior between different libpng builds!) + */ + png_colorspace colorspace; +#endif + +#ifdef PNG_iCCP_SUPPORTED + /* iCCP chunk data. */ + png_charp iccp_name; /* profile name */ + png_bytep iccp_profile; /* International Color Consortium profile data */ + png_uint_32 iccp_proflen; /* ICC profile data length */ +#endif + +#ifdef PNG_TEXT_SUPPORTED + /* The tEXt, and zTXt chunks contain human-readable textual data in + * uncompressed, compressed, and optionally compressed forms, respectively. + * The data in "text" is an array of pointers to uncompressed, + * null-terminated C strings. Each chunk has a keyword that describes the + * textual data contained in that chunk. Keywords are not required to be + * unique, and the text string may be empty. Any number of text chunks may + * be in an image. + */ + int num_text; /* number of comments read or comments to write */ + int max_text; /* current size of text array */ + png_textp text; /* array of comments read or comments to write */ +#endif /* TEXT */ + +#ifdef PNG_tIME_SUPPORTED + /* The tIME chunk holds the last time the displayed image data was + * modified. See the png_time struct for the contents of this struct. + */ + png_time mod_time; +#endif + +#ifdef PNG_sBIT_SUPPORTED + /* The sBIT chunk specifies the number of significant high-order bits + * in the pixel data. Values are in the range [1, bit_depth], and are + * only specified for the channels in the pixel data. The contents of + * the low-order bits is not specified. Data is valid if + * (valid & PNG_INFO_sBIT) is non-zero. + */ + png_color_8 sig_bit; /* significant bits in color channels */ +#endif + +#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \ +defined(PNG_READ_BACKGROUND_SUPPORTED) + /* The tRNS chunk supplies transparency data for paletted images and + * other image types that don't need a full alpha channel. There are + * "num_trans" transparency values for a paletted image, stored in the + * same order as the palette colors, starting from index 0. Values + * for the data are in the range [0, 255], ranging from fully transparent + * to fully opaque, respectively. For non-paletted images, there is a + * single color specified that should be treated as fully transparent. + * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. + */ + png_bytep trans_alpha; /* alpha values for paletted image */ + png_color_16 trans_color; /* transparent color for non-palette image */ +#endif + +#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + /* The bKGD chunk gives the suggested image background color if the + * display program does not have its own background color and the image + * is needs to composited onto a background before display. The colors + * in "background" are normally in the same color space/depth as the + * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero. + */ + png_color_16 background; +#endif + +#ifdef PNG_oFFs_SUPPORTED + /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards + * and downwards from the top-left corner of the display, page, or other + * application-specific co-ordinate space. See the PNG_OFFSET_ defines + * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero. + */ + png_int_32 x_offset; /* x offset on page */ + png_int_32 y_offset; /* y offset on page */ + png_byte offset_unit_type; /* offset units type */ +#endif + +#ifdef PNG_pHYs_SUPPORTED + /* The pHYs chunk gives the physical pixel density of the image for + * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_ + * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero. + */ + png_uint_32 x_pixels_per_unit; /* horizontal pixel density */ + png_uint_32 y_pixels_per_unit; /* vertical pixel density */ + png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */ +#endif + +#ifdef PNG_hIST_SUPPORTED + /* The hIST chunk contains the relative frequency or importance of the + * various palette entries, so that a viewer can intelligently select a + * reduced-color palette, if required. Data is an array of "num_palette" + * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST) + * is non-zero. + */ + png_uint_16p hist; +#endif + +#ifdef PNG_pCAL_SUPPORTED + /* The pCAL chunk describes a transformation between the stored pixel + * values and original physical data values used to create the image. + * The integer range [0, 2^bit_depth - 1] maps to the floating-point + * range given by [pcal_X0, pcal_X1], and are further transformed by a + * (possibly non-linear) transformation function given by "pcal_type" + * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_ + * defines below, and the PNG-Group's PNG extensions document for a + * complete description of the transformations and how they should be + * implemented, and for a description of the ASCII parameter strings. + * Data values are valid if (valid & PNG_INFO_pCAL) non-zero. + */ + png_charp pcal_purpose; /* pCAL chunk description string */ + png_int_32 pcal_X0; /* minimum value */ + png_int_32 pcal_X1; /* maximum value */ + png_charp pcal_units; /* Latin-1 string giving physical units */ + png_charpp pcal_params; /* ASCII strings containing parameter values */ + png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */ + png_byte pcal_nparams; /* number of parameters given in pcal_params */ +#endif + +/* New members added in libpng-1.0.6 */ + png_uint_32 free_me; /* flags items libpng is responsible for freeing */ + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + /* Storage for unknown chunks that the library doesn't recognize. */ + png_unknown_chunkp unknown_chunks; + + /* The type of this field is limited by the type of + * png_struct::user_chunk_cache_max, else overflow can occur. + */ + int unknown_chunks_num; +#endif + +#ifdef PNG_sPLT_SUPPORTED + /* Data on sPLT chunks (there may be more than one). */ + png_sPLT_tp splt_palettes; + int splt_palettes_num; /* Match type returned by png_get API */ +#endif + +#ifdef PNG_sCAL_SUPPORTED + /* The sCAL chunk describes the actual physical dimensions of the + * subject matter of the graphic. The chunk contains a unit specification + * a byte value, and two ASCII strings representing floating-point + * values. The values are width and height corresponsing to one pixel + * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is + * non-zero. + */ + png_byte scal_unit; /* unit of physical scale */ + png_charp scal_s_width; /* string containing height */ + png_charp scal_s_height; /* string containing width */ +#endif + +#ifdef PNG_INFO_IMAGE_SUPPORTED + /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) + non-zero */ + /* Data valid if (valid & PNG_INFO_IDAT) non-zero */ + png_bytepp row_pointers; /* the image bits */ +#endif + +}; +#endif /* PNGINFO_H */ diff --git a/thirdparty/libpng/pnglibconf.h b/thirdparty/libpng/pnglibconf.h new file mode 100644 index 0000000000..3e70aa1170 --- /dev/null +++ b/thirdparty/libpng/pnglibconf.h @@ -0,0 +1,215 @@ +/* libpng 1.6.23 STANDARD API DEFINITION */ + +/* pnglibconf.h - library build configuration */ + +/* Libpng version 1.6.23 - June 9, 2016 */ + +/* Copyright (c) 1998-2015 Glenn Randers-Pehrson */ + +/* This code is released under the libpng license. */ +/* For conditions of distribution and use, see the disclaimer */ +/* and license in png.h */ + +/* pnglibconf.h */ +/* Machine generated file: DO NOT EDIT */ +/* Derived from: scripts/pnglibconf.dfa */ +#ifndef PNGLCONF_H +#define PNGLCONF_H +/* options */ +#define PNG_16BIT_SUPPORTED +#define PNG_ALIGNED_MEMORY_SUPPORTED +/*#undef PNG_ARM_NEON_API_SUPPORTED*/ +/*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/ +#define PNG_BENIGN_ERRORS_SUPPORTED +#define PNG_BENIGN_READ_ERRORS_SUPPORTED +/*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/ +#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED +#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED +#define PNG_COLORSPACE_SUPPORTED +#define PNG_CONSOLE_IO_SUPPORTED +#define PNG_CONVERT_tIME_SUPPORTED +#define PNG_EASY_ACCESS_SUPPORTED +/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/ +#define PNG_ERROR_TEXT_SUPPORTED +#define PNG_FIXED_POINT_SUPPORTED +#define PNG_FLOATING_ARITHMETIC_SUPPORTED +#define PNG_FLOATING_POINT_SUPPORTED +#define PNG_FORMAT_AFIRST_SUPPORTED +#define PNG_FORMAT_BGR_SUPPORTED +#define PNG_GAMMA_SUPPORTED +#define PNG_GET_PALETTE_MAX_SUPPORTED +#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED +#define PNG_INCH_CONVERSIONS_SUPPORTED +#define PNG_INFO_IMAGE_SUPPORTED +#define PNG_IO_STATE_SUPPORTED +#define PNG_MNG_FEATURES_SUPPORTED +#define PNG_POINTER_INDEXING_SUPPORTED +#define PNG_PROGRESSIVE_READ_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED +#define PNG_READ_ALPHA_MODE_SUPPORTED +#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_READ_BACKGROUND_SUPPORTED +#define PNG_READ_BGR_SUPPORTED +#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED +#define PNG_READ_COMPOSITE_NODIV_SUPPORTED +#define PNG_READ_COMPRESSED_TEXT_SUPPORTED +#define PNG_READ_EXPAND_16_SUPPORTED +#define PNG_READ_EXPAND_SUPPORTED +#define PNG_READ_FILLER_SUPPORTED +#define PNG_READ_GAMMA_SUPPORTED +#define PNG_READ_GET_PALETTE_MAX_SUPPORTED +#define PNG_READ_GRAY_TO_RGB_SUPPORTED +#define PNG_READ_INTERLACING_SUPPORTED +#define PNG_READ_INT_FUNCTIONS_SUPPORTED +#define PNG_READ_INVERT_ALPHA_SUPPORTED +#define PNG_READ_INVERT_SUPPORTED +#define PNG_READ_OPT_PLTE_SUPPORTED +#define PNG_READ_PACKSWAP_SUPPORTED +#define PNG_READ_PACK_SUPPORTED +#define PNG_READ_QUANTIZE_SUPPORTED +#define PNG_READ_RGB_TO_GRAY_SUPPORTED +#define PNG_READ_SCALE_16_TO_8_SUPPORTED +#define PNG_READ_SHIFT_SUPPORTED +#define PNG_READ_STRIP_16_TO_8_SUPPORTED +#define PNG_READ_STRIP_ALPHA_SUPPORTED +#define PNG_READ_SUPPORTED +#define PNG_READ_SWAP_ALPHA_SUPPORTED +#define PNG_READ_SWAP_SUPPORTED +#define PNG_READ_TEXT_SUPPORTED +#define PNG_READ_TRANSFORMS_SUPPORTED +#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_READ_USER_CHUNKS_SUPPORTED +#define PNG_READ_USER_TRANSFORM_SUPPORTED +#define PNG_READ_bKGD_SUPPORTED +#define PNG_READ_cHRM_SUPPORTED +#define PNG_READ_gAMA_SUPPORTED +#define PNG_READ_hIST_SUPPORTED +#define PNG_READ_iCCP_SUPPORTED +#define PNG_READ_iTXt_SUPPORTED +#define PNG_READ_oFFs_SUPPORTED +#define PNG_READ_pCAL_SUPPORTED +#define PNG_READ_pHYs_SUPPORTED +#define PNG_READ_sBIT_SUPPORTED +#define PNG_READ_sCAL_SUPPORTED +#define PNG_READ_sPLT_SUPPORTED +#define PNG_READ_sRGB_SUPPORTED +#define PNG_READ_tEXt_SUPPORTED +#define PNG_READ_tIME_SUPPORTED +#define PNG_READ_tRNS_SUPPORTED +#define PNG_READ_zTXt_SUPPORTED +#define PNG_SAVE_INT_32_SUPPORTED +#define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_SEQUENTIAL_READ_SUPPORTED +#define PNG_SETJMP_SUPPORTED +#define PNG_SET_OPTION_SUPPORTED +#define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_SET_USER_LIMITS_SUPPORTED +#define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED +#define PNG_SIMPLIFIED_READ_BGR_SUPPORTED +#define PNG_SIMPLIFIED_READ_SUPPORTED +#define PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED +#define PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED +#define PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +#define PNG_SIMPLIFIED_WRITE_SUPPORTED +#define PNG_STDIO_SUPPORTED +#define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_TEXT_SUPPORTED +#define PNG_TIME_RFC1123_SUPPORTED +#define PNG_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_USER_CHUNKS_SUPPORTED +#define PNG_USER_LIMITS_SUPPORTED +#define PNG_USER_MEM_SUPPORTED +#define PNG_USER_TRANSFORM_INFO_SUPPORTED +#define PNG_USER_TRANSFORM_PTR_SUPPORTED +#define PNG_WARNINGS_SUPPORTED +#define PNG_WRITE_16BIT_SUPPORTED +#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_WRITE_BGR_SUPPORTED +#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED +#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED +#define PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED +#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +#define PNG_WRITE_FILLER_SUPPORTED +#define PNG_WRITE_FILTER_SUPPORTED +#define PNG_WRITE_FLUSH_SUPPORTED +#define PNG_WRITE_GET_PALETTE_MAX_SUPPORTED +#define PNG_WRITE_INTERLACING_SUPPORTED +#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED +#define PNG_WRITE_INVERT_ALPHA_SUPPORTED +#define PNG_WRITE_INVERT_SUPPORTED +#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED +#define PNG_WRITE_PACKSWAP_SUPPORTED +#define PNG_WRITE_PACK_SUPPORTED +#define PNG_WRITE_SHIFT_SUPPORTED +#define PNG_WRITE_SUPPORTED +#define PNG_WRITE_SWAP_ALPHA_SUPPORTED +#define PNG_WRITE_SWAP_SUPPORTED +#define PNG_WRITE_TEXT_SUPPORTED +#define PNG_WRITE_TRANSFORMS_SUPPORTED +#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_WRITE_USER_TRANSFORM_SUPPORTED +#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED +#define PNG_WRITE_bKGD_SUPPORTED +#define PNG_WRITE_cHRM_SUPPORTED +#define PNG_WRITE_gAMA_SUPPORTED +#define PNG_WRITE_hIST_SUPPORTED +#define PNG_WRITE_iCCP_SUPPORTED +#define PNG_WRITE_iTXt_SUPPORTED +#define PNG_WRITE_oFFs_SUPPORTED +#define PNG_WRITE_pCAL_SUPPORTED +#define PNG_WRITE_pHYs_SUPPORTED +#define PNG_WRITE_sBIT_SUPPORTED +#define PNG_WRITE_sCAL_SUPPORTED +#define PNG_WRITE_sPLT_SUPPORTED +#define PNG_WRITE_sRGB_SUPPORTED +#define PNG_WRITE_tEXt_SUPPORTED +#define PNG_WRITE_tIME_SUPPORTED +#define PNG_WRITE_tRNS_SUPPORTED +#define PNG_WRITE_zTXt_SUPPORTED +#define PNG_bKGD_SUPPORTED +#define PNG_cHRM_SUPPORTED +#define PNG_gAMA_SUPPORTED +#define PNG_hIST_SUPPORTED +#define PNG_iCCP_SUPPORTED +#define PNG_iTXt_SUPPORTED +#define PNG_oFFs_SUPPORTED +#define PNG_pCAL_SUPPORTED +#define PNG_pHYs_SUPPORTED +#define PNG_sBIT_SUPPORTED +#define PNG_sCAL_SUPPORTED +#define PNG_sPLT_SUPPORTED +#define PNG_sRGB_SUPPORTED +#define PNG_tEXt_SUPPORTED +#define PNG_tIME_SUPPORTED +#define PNG_tRNS_SUPPORTED +#define PNG_zTXt_SUPPORTED +/* end of options */ +/* settings */ +#define PNG_API_RULE 0 +#define PNG_DEFAULT_READ_MACROS 1 +#define PNG_GAMMA_THRESHOLD_FIXED 5000 +#define PNG_IDAT_READ_SIZE PNG_ZBUF_SIZE +#define PNG_INFLATE_BUF_SIZE 1024 +#define PNG_LINKAGE_API extern +#define PNG_LINKAGE_CALLBACK extern +#define PNG_LINKAGE_DATA extern +#define PNG_LINKAGE_FUNCTION extern +#define PNG_MAX_GAMMA_8 11 +#define PNG_QUANTIZE_BLUE_BITS 5 +#define PNG_QUANTIZE_GREEN_BITS 5 +#define PNG_QUANTIZE_RED_BITS 5 +#define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1) +#define PNG_TEXT_Z_DEFAULT_STRATEGY 0 +#define PNG_USER_CHUNK_CACHE_MAX 1000 +#define PNG_USER_CHUNK_MALLOC_MAX 8000000 +#define PNG_USER_HEIGHT_MAX 1000000 +#define PNG_USER_WIDTH_MAX 1000000 +#define PNG_ZBUF_SIZE 8192 +#define PNG_ZLIB_VERNUM 0 /* unknown */ +#define PNG_Z_DEFAULT_COMPRESSION (-1) +#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0 +#define PNG_Z_DEFAULT_STRATEGY 1 +#define PNG_sCAL_PRECISION 5 +#define PNG_sRGB_PROFILE_CHECKS 2 +/* end of settings */ +#endif /* PNGLCONF_H */ diff --git a/thirdparty/libpng/pngmem.c b/thirdparty/libpng/pngmem.c new file mode 100644 index 0000000000..7bcfd00507 --- /dev/null +++ b/thirdparty/libpng/pngmem.c @@ -0,0 +1,284 @@ + +/* pngmem.c - stub functions for memory allocation + * + * Last changed in libpng 1.6.15 [November 20, 2014] + * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all memory allocation. Users who + * need special memory handling are expected to supply replacement + * functions for png_malloc() and png_free(), and to use + * png_create_read_struct_2() and png_create_write_struct_2() to + * identify the replacement functions. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +/* Free a png_struct */ +void /* PRIVATE */ +png_destroy_png_struct(png_structrp png_ptr) +{ + if (png_ptr != NULL) + { + /* png_free might call png_error and may certainly call + * png_get_mem_ptr, so fake a temporary png_struct to support this. + */ + png_struct dummy_struct = *png_ptr; + memset(png_ptr, 0, (sizeof *png_ptr)); + png_free(&dummy_struct, png_ptr); + +# ifdef PNG_SETJMP_SUPPORTED + /* We may have a jmp_buf left to deallocate. */ + png_free_jmpbuf(&dummy_struct); +# endif + } +} + +/* Allocate memory. For reasonable files, size should never exceed + * 64K. However, zlib may allocate more than 64K if you don't tell + * it not to. See zconf.h and png.h for more information. zlib does + * need to allocate exactly 64K, so whatever you call here must + * have the ability to do that. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + ret = png_malloc(png_ptr, size); + + if (ret != NULL) + memset(ret, 0, size); + + return ret; +} + +/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of + * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED. + * Checking and error handling must happen outside this routine; it returns NULL + * if the allocation cannot be done (for any reason.) + */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED) +{ + /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS + * allocators have also been removed in 1.6.0, so any 16-bit system now has + * to implement a user memory handler. This checks to be sure it isn't + * called with big numbers. + */ +#ifndef PNG_USER_MEM_SUPPORTED + PNG_UNUSED(png_ptr) +#endif + + /* Some compilers complain that this is always true. However, it + * can be false when integer overflow happens. + */ + if (size > 0 && size <= PNG_SIZE_MAX +# ifdef PNG_MAX_MALLOC_64K + && size <= 65536U +# endif + ) + { +#ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr != NULL && png_ptr->malloc_fn != NULL) + return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size); + + else +#endif + return malloc((size_t)size); /* checked for truncation above */ + } + + else + return NULL; +} + +#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\ + defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) +/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7 + * that arises because of the checks in png_realloc_array that are repeated in + * png_malloc_array. + */ +static png_voidp +png_malloc_array_checked(png_const_structrp png_ptr, int nelements, + size_t element_size) +{ + png_alloc_size_t req = nelements; /* known to be > 0 */ + + if (req <= PNG_SIZE_MAX/element_size) + return png_malloc_base(png_ptr, req * element_size); + + /* The failure case when the request is too large */ + return NULL; +} + +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_malloc_array,(png_const_structrp png_ptr, int nelements, + size_t element_size),PNG_ALLOCATED) +{ + if (nelements <= 0 || element_size == 0) + png_error(png_ptr, "internal error: array alloc"); + + return png_malloc_array_checked(png_ptr, nelements, element_size); +} + +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array, + int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED) +{ + /* These are internal errors: */ + if (add_elements <= 0 || element_size == 0 || old_elements < 0 || + (old_array == NULL && old_elements > 0)) + png_error(png_ptr, "internal error: array realloc"); + + /* Check for overflow on the elements count (so the caller does not have to + * check.) + */ + if (add_elements <= INT_MAX - old_elements) + { + png_voidp new_array = png_malloc_array_checked(png_ptr, + old_elements+add_elements, element_size); + + if (new_array != NULL) + { + /* Because png_malloc_array worked the size calculations below cannot + * overflow. + */ + if (old_elements > 0) + memcpy(new_array, old_array, element_size*(unsigned)old_elements); + + memset((char*)new_array + element_size*(unsigned)old_elements, 0, + element_size*(unsigned)add_elements); + + return new_array; + } + } + + return NULL; /* error */ +} +#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */ + +/* Various functions that have different error handling are derived from this. + * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate + * function png_malloc_default is also provided. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + if (png_ptr == NULL) + return NULL; + + ret = png_malloc_base(png_ptr, size); + + if (ret == NULL) + png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */ + + return ret; +} + +#ifdef PNG_USER_MEM_SUPPORTED +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED PNG_DEPRECATED) +{ + png_voidp ret; + + if (png_ptr == NULL) + return NULL; + + /* Passing 'NULL' here bypasses the application provided memory handler. */ + ret = png_malloc_base(NULL/*use malloc*/, size); + + if (ret == NULL) + png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */ + + return ret; +} +#endif /* USER_MEM */ + +/* This function was added at libpng version 1.2.3. The png_malloc_warn() + * function will issue a png_warning and return NULL instead of issuing a + * png_error, if it fails to allocate the requested memory. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED) +{ + if (png_ptr != NULL) + { + png_voidp ret = png_malloc_base(png_ptr, size); + + if (ret != NULL) + return ret; + + png_warning(png_ptr, "Out of memory"); + } + + return NULL; +} + +/* Free a pointer allocated by png_malloc(). If ptr is NULL, return + * without taking any action. + */ +void PNGAPI +png_free(png_const_structrp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + +#ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->free_fn != NULL) + png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr); + + else + png_free_default(png_ptr, ptr); +} + +PNG_FUNCTION(void,PNGAPI +png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED) +{ + if (png_ptr == NULL || ptr == NULL) + return; +#endif /* USER_MEM */ + + free(ptr); +} + +#ifdef PNG_USER_MEM_SUPPORTED +/* This function is called when the application wants to use another method + * of allocating and freeing memory. + */ +void PNGAPI +png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr + malloc_fn, png_free_ptr free_fn) +{ + if (png_ptr != NULL) + { + png_ptr->mem_ptr = mem_ptr; + png_ptr->malloc_fn = malloc_fn; + png_ptr->free_fn = free_fn; + } +} + +/* This function returns a pointer to the mem_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp PNGAPI +png_get_mem_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return NULL; + + return png_ptr->mem_ptr; +} +#endif /* USER_MEM */ +#endif /* READ || WRITE */ diff --git a/thirdparty/libpng/pngpread.c b/thirdparty/libpng/pngpread.c new file mode 100644 index 0000000000..ca300e7f16 --- /dev/null +++ b/thirdparty/libpng/pngpread.c @@ -0,0 +1,1090 @@ + +/* pngpread.c - read a png file in push mode + * + * Last changed in libpng 1.6.23 [June 9, 2016] + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + +/* Push model modes */ +#define PNG_READ_SIG_MODE 0 +#define PNG_READ_CHUNK_MODE 1 +#define PNG_READ_IDAT_MODE 2 +#define PNG_READ_tEXt_MODE 4 +#define PNG_READ_zTXt_MODE 5 +#define PNG_READ_DONE_MODE 6 +#define PNG_READ_iTXt_MODE 7 +#define PNG_ERROR_MODE 8 + +#define PNG_PUSH_SAVE_BUFFER_IF_FULL \ +if (png_ptr->push_length + 4 > png_ptr->buffer_size) \ + { png_push_save_buffer(png_ptr); return; } +#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \ +if (png_ptr->buffer_size < N) \ + { png_push_save_buffer(png_ptr); return; } + +void PNGAPI +png_process_data(png_structrp png_ptr, png_inforp info_ptr, + png_bytep buffer, png_size_t buffer_size) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_push_restore_buffer(png_ptr, buffer, buffer_size); + + while (png_ptr->buffer_size) + { + png_process_some_data(png_ptr, info_ptr); + } +} + +png_size_t PNGAPI +png_process_data_pause(png_structrp png_ptr, int save) +{ + if (png_ptr != NULL) + { + /* It's easiest for the caller if we do the save; then the caller doesn't + * have to supply the same data again: + */ + if (save != 0) + png_push_save_buffer(png_ptr); + else + { + /* This includes any pending saved bytes: */ + png_size_t remaining = png_ptr->buffer_size; + png_ptr->buffer_size = 0; + + /* So subtract the saved buffer size, unless all the data + * is actually 'saved', in which case we just return 0 + */ + if (png_ptr->save_buffer_size < remaining) + return remaining - png_ptr->save_buffer_size; + } + } + + return 0; +} + +png_uint_32 PNGAPI +png_process_data_skip(png_structrp png_ptr) +{ + /* TODO: Deprecate and remove this API. + * Somewhere the implementation of this seems to have been lost, + * or abandoned. It was only to support some internal back-door access + * to png_struct) in libpng-1.4.x. + */ + png_app_warning(png_ptr, +"png_process_data_skip is not implemented in any current version of libpng"); + return 0; +} + +/* What we do with the incoming data depends on what we were previously + * doing before we ran out of data... + */ +void /* PRIVATE */ +png_process_some_data(png_structrp png_ptr, png_inforp info_ptr) +{ + if (png_ptr == NULL) + return; + + switch (png_ptr->process_mode) + { + case PNG_READ_SIG_MODE: + { + png_push_read_sig(png_ptr, info_ptr); + break; + } + + case PNG_READ_CHUNK_MODE: + { + png_push_read_chunk(png_ptr, info_ptr); + break; + } + + case PNG_READ_IDAT_MODE: + { + png_push_read_IDAT(png_ptr); + break; + } + + default: + { + png_ptr->buffer_size = 0; + break; + } + } +} + +/* Read any remaining signature bytes from the stream and compare them with + * the correct PNG signature. It is possible that this routine is called + * with bytes already read from the signature, either because they have been + * checked by the calling application, or because of multiple calls to this + * routine. + */ +void /* PRIVATE */ +png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr) +{ + png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ + num_to_check = 8 - num_checked; + + if (png_ptr->buffer_size < num_to_check) + { + num_to_check = png_ptr->buffer_size; + } + + png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), + num_to_check); + png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + else + { + if (png_ptr->sig_bytes >= 8) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } + } +} + +void /* PRIVATE */ +png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr) +{ + png_uint_32 chunk_name; +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int keep; /* unknown handling method */ +#endif + + /* First we make sure we have enough data for the 4-byte chunk name + * and the 4-byte chunk length before proceeding with decoding the + * chunk data. To fully decode each of these chunks, we also make + * sure we have enough data in the buffer for the 4-byte CRC at the + * end of every chunk (except IDAT, which is handled separately). + */ + if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) + { + png_byte chunk_length[4]; + png_byte chunk_tag[4]; + + PNG_PUSH_SAVE_BUFFER_IF_LT(8) + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + } + + chunk_name = png_ptr->chunk_name; + + if (chunk_name == png_IDAT) + { + if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + /* If we reach an IDAT chunk, this means we have read all of the + * header chunks, and we can start reading the image (or if this + * is called after the image has been read - we have an error). + */ + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + (png_ptr->mode & PNG_HAVE_PLTE) == 0) + png_error(png_ptr, "Missing PLTE before IDAT"); + + png_ptr->process_mode = PNG_READ_IDAT_MODE; + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0) + if (png_ptr->push_length == 0) + return; + + png_ptr->mode |= PNG_HAVE_IDAT; + + if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) + png_benign_error(png_ptr, "Too many IDATs found"); + } + + if (chunk_name == png_IHDR) + { + if (png_ptr->push_length != 13) + png_error(png_ptr, "Invalid IHDR length"); + + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (chunk_name == png_IEND) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); + + png_ptr->process_mode = PNG_READ_DONE_MODE; + png_push_have_end(png_ptr, info_ptr); + } + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep); + + if (chunk_name == png_PLTE) + png_ptr->mode |= PNG_HAVE_PLTE; + } +#endif + + else if (chunk_name == png_PLTE) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (chunk_name == png_IDAT) + { + png_ptr->idat_size = png_ptr->push_length; + png_ptr->process_mode = PNG_READ_IDAT_MODE; + png_push_have_info(png_ptr, info_ptr); + png_ptr->zstream.avail_out = + (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; + png_ptr->zstream.next_out = png_ptr->row_buf; + return; + } + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (png_ptr->chunk_name == png_gAMA) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + else if (png_ptr->chunk_name == png_sBIT) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + else if (png_ptr->chunk_name == png_cHRM) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + else if (chunk_name == png_sRGB) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + else if (png_ptr->chunk_name == png_iCCP) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + else if (chunk_name == png_sPLT) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + else if (chunk_name == png_tRNS) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_bKGD_SUPPORTED + else if (chunk_name == png_bKGD) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_hIST_SUPPORTED + else if (chunk_name == png_hIST) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + else if (chunk_name == png_pHYs) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + else if (chunk_name == png_oFFs) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (chunk_name == png_pCAL) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + else if (chunk_name == png_sCAL) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tIME_SUPPORTED + else if (chunk_name == png_tIME) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + else if (chunk_name == png_tEXt) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + else if (chunk_name == png_zTXt) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + else if (chunk_name == png_iTXt) + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + + else + { + PNG_PUSH_SAVE_BUFFER_IF_FULL + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, + PNG_HANDLE_CHUNK_AS_DEFAULT); + } + + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; +} + +void PNGCBAPI +png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) +{ + png_bytep ptr; + + if (png_ptr == NULL) + return; + + ptr = buffer; + if (png_ptr->save_buffer_size != 0) + { + png_size_t save_size; + + if (length < png_ptr->save_buffer_size) + save_size = length; + + else + save_size = png_ptr->save_buffer_size; + + memcpy(ptr, png_ptr->save_buffer_ptr, save_size); + length -= save_size; + ptr += save_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + if (length != 0 && png_ptr->current_buffer_size != 0) + { + png_size_t save_size; + + if (length < png_ptr->current_buffer_size) + save_size = length; + + else + save_size = png_ptr->current_buffer_size; + + memcpy(ptr, png_ptr->current_buffer_ptr, save_size); + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } +} + +void /* PRIVATE */ +png_push_save_buffer(png_structrp png_ptr) +{ + if (png_ptr->save_buffer_size != 0) + { + if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) + { + png_size_t i, istop; + png_bytep sp; + png_bytep dp; + + istop = png_ptr->save_buffer_size; + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; + i < istop; i++, sp++, dp++) + { + *dp = *sp; + } + } + } + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > + png_ptr->save_buffer_max) + { + png_size_t new_max; + png_bytep old_buffer; + + if (png_ptr->save_buffer_size > PNG_SIZE_MAX - + (png_ptr->current_buffer_size + 256)) + { + png_error(png_ptr, "Potential overflow of save_buffer"); + } + + new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; + old_buffer = png_ptr->save_buffer; + png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, + (png_size_t)new_max); + + if (png_ptr->save_buffer == NULL) + { + png_free(png_ptr, old_buffer); + png_error(png_ptr, "Insufficient memory for save_buffer"); + } + + if (old_buffer) + memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); + else if (png_ptr->save_buffer_size) + png_error(png_ptr, "save_buffer error"); + png_free(png_ptr, old_buffer); + png_ptr->save_buffer_max = new_max; + } + if (png_ptr->current_buffer_size) + { + memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, + png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); + png_ptr->save_buffer_size += png_ptr->current_buffer_size; + png_ptr->current_buffer_size = 0; + } + png_ptr->save_buffer_ptr = png_ptr->save_buffer; + png_ptr->buffer_size = 0; +} + +void /* PRIVATE */ +png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + png_ptr->current_buffer = buffer; + png_ptr->current_buffer_size = buffer_length; + png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; + png_ptr->current_buffer_ptr = png_ptr->current_buffer; +} + +void /* PRIVATE */ +png_push_read_IDAT(png_structrp png_ptr) +{ + if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0) + { + png_byte chunk_length[4]; + png_byte chunk_tag[4]; + + /* TODO: this code can be commoned up with the same code in push_read */ + PNG_PUSH_SAVE_BUFFER_IF_LT(8) + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, chunk_tag, 4); + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + + if (png_ptr->chunk_name != png_IDAT) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + png_error(png_ptr, "Not enough compressed data"); + + return; + } + + png_ptr->idat_size = png_ptr->push_length; + } + + if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0) + { + png_size_t save_size = png_ptr->save_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. Do not cast in the following test - it + * will break on either 16-bit or 64-bit platforms. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + + if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0) + { + png_size_t save_size = png_ptr->current_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } + + if (png_ptr->idat_size == 0) + { + PNG_PUSH_SAVE_BUFFER_IF_LT(4) + png_crc_finish(png_ptr, 0); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->zowner = 0; + } +} + +void /* PRIVATE */ +png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + /* The caller checks for a non-zero buffer length. */ + if (!(buffer_length > 0) || buffer == NULL) + png_error(png_ptr, "No IDAT data (internal error)"); + + /* This routine must process all the data it has been given + * before returning, calling the row callback as required to + * handle the uncompressed results. + */ + png_ptr->zstream.next_in = buffer; + /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ + png_ptr->zstream.avail_in = (uInt)buffer_length; + + /* Keep going until the decompressed data is all processed + * or the stream marked as finished. + */ + while (png_ptr->zstream.avail_in > 0 && + (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + { + int ret; + + /* We have data for zlib, but we must check that zlib + * has someplace to put the results. It doesn't matter + * if we don't expect any results -- it may be the input + * data is just the LZ end code. + */ + if (!(png_ptr->zstream.avail_out > 0)) + { + /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ + png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1); + + png_ptr->zstream.next_out = png_ptr->row_buf; + } + + /* Using Z_SYNC_FLUSH here means that an unterminated + * LZ stream (a stream with a missing end code) can still + * be handled, otherwise (Z_NO_FLUSH) a future zlib + * implementation might defer output and therefore + * change the current behavior (see comments in inflate.c + * for why this doesn't happen at present with zlib 1.2.5). + */ + ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH); + + /* Check for any failure before proceeding. */ + if (ret != Z_OK && ret != Z_STREAM_END) + { + /* Terminate the decompression. */ + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + png_ptr->zowner = 0; + + /* This may be a truncated stream (missing or + * damaged end code). Treat that as a warning. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + png_warning(png_ptr, "Truncated compressed data in IDAT"); + + else + png_error(png_ptr, "Decompression error in IDAT"); + + /* Skip the check on unprocessed input */ + return; + } + + /* Did inflate output any data? */ + if (png_ptr->zstream.next_out != png_ptr->row_buf) + { + /* Is this unexpected data after the last row? + * If it is, artificially terminate the LZ output + * here. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + { + /* Extra data. */ + png_warning(png_ptr, "Extra compressed data in IDAT"); + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + png_ptr->zowner = 0; + + /* Do no more processing; skip the unprocessed + * input check below. + */ + return; + } + + /* Do we have a complete row? */ + if (png_ptr->zstream.avail_out == 0) + png_push_process_row(png_ptr); + } + + /* And check for the end of the stream. */ + if (ret == Z_STREAM_END) + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + } + + /* All the data should have been processed, if anything + * is left at this point we have bytes of IDAT data + * after the zlib end code. + */ + if (png_ptr->zstream.avail_in > 0) + png_warning(png_ptr, "Extra compression data in IDAT"); +} + +void /* PRIVATE */ +png_push_process_row(png_structrp png_ptr) +{ + /* 1.5.6: row_info moved out of png_struct to a local here. */ + png_row_info row_info; + + row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ + row_info.color_type = png_ptr->color_type; + row_info.bit_depth = png_ptr->bit_depth; + row_info.channels = png_ptr->channels; + row_info.pixel_depth = png_ptr->pixel_depth; + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + + if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) + { + if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, + png_ptr->prev_row + 1, png_ptr->row_buf[0]); + else + png_error(png_ptr, "bad adaptive filter value"); + } + + /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before + * 1.5.6, while the buffer really is this big in current versions of libpng + * it may not be in the future, so this was changed just to copy the + * interlaced row count: + */ + memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + if (png_ptr->transformations != 0) + png_do_read_transformations(png_ptr, &row_info); +#endif + + /* The transformed pixel depth should match the depth now in row_info. */ + if (png_ptr->transformed_pixel_depth == 0) + { + png_ptr->transformed_pixel_depth = row_info.pixel_depth; + if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) + png_error(png_ptr, "progressive row overflow"); + } + + else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) + png_error(png_ptr, "internal progressive row size calculation error"); + + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Expand interlaced rows to full size */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + if (png_ptr->pass < 6) + png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, + png_ptr->transformations); + + switch (png_ptr->pass) + { + case 0: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 0; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */ + } + + if (png_ptr->pass == 2) /* Pass 1 might be empty */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 4 && png_ptr->height <= 4) + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 6 && png_ptr->height <= 4) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 1: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 1; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 2) /* Skip top 4 generated rows */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 2: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Pass 3 might be empty */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 3: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 3; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Skip top two generated rows */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 4: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Pass 5 might be empty */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 5: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 5; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Skip top generated row */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + default: + case 6: + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + + if (png_ptr->pass != 6) + break; + + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + } + else +#endif + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } +} + +void /* PRIVATE */ +png_read_push_finish_row(png_structrp png_ptr) +{ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + + /* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h + static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; + */ +#endif + + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced != 0) + { + png_ptr->row_number = 0; + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + do + { + png_ptr->pass++; + if ((png_ptr->pass == 1 && png_ptr->width < 5) || + (png_ptr->pass == 3 && png_ptr->width < 3) || + (png_ptr->pass == 5 && png_ptr->width < 2)) + png_ptr->pass++; + + if (png_ptr->pass > 7) + png_ptr->pass--; + + if (png_ptr->pass >= 7) + break; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + if ((png_ptr->transformations & PNG_INTERLACE) != 0) + break; + + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + + } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); + } +#endif /* READ_INTERLACING */ +} + +void /* PRIVATE */ +png_push_have_info(png_structrp png_ptr, png_inforp info_ptr) +{ + if (png_ptr->info_fn != NULL) + (*(png_ptr->info_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_end(png_structrp png_ptr, png_inforp info_ptr) +{ + if (png_ptr->end_fn != NULL) + (*(png_ptr->end_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_row(png_structrp png_ptr, png_bytep row) +{ + if (png_ptr->row_fn != NULL) + (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, + (int)png_ptr->pass); +} + +#ifdef PNG_READ_INTERLACING_SUPPORTED +void PNGAPI +png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row, + png_const_bytep new_row) +{ + if (png_ptr == NULL) + return; + + /* new_row is a flag here - if it is NULL then the app callback was called + * from an empty row (see the calls to png_struct::row_fn below), otherwise + * it must be png_ptr->row_buf+1 + */ + if (new_row != NULL) + png_combine_row(png_ptr, old_row, 1/*blocky display*/); +} +#endif /* READ_INTERLACING */ + +void PNGAPI +png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr, + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, + png_progressive_end_ptr end_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->info_fn = info_fn; + png_ptr->row_fn = row_fn; + png_ptr->end_fn = end_fn; + + png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); +} + +png_voidp PNGAPI +png_get_progressive_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return png_ptr->io_ptr; +} +#endif /* PROGRESSIVE_READ */ diff --git a/thirdparty/libpng/pngpriv.h b/thirdparty/libpng/pngpriv.h new file mode 100644 index 0000000000..9338df3144 --- /dev/null +++ b/thirdparty/libpng/pngpriv.h @@ -0,0 +1,1932 @@ + +/* pngpriv.h - private declarations for use inside libpng + * + * Last changed in libpng 1.6.22 [May 26, 2016] + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* The symbols declared in this file (including the functions declared + * as extern) are PRIVATE. They are not part of the libpng public + * interface, and are not recommended for use by regular applications. + * Some of them may become public in the future; others may stay private, + * change in an incompatible way, or even disappear. + * Although the libpng users are not forbidden to include this header, + * they should be well aware of the issues that may arise from doing so. + */ + +#ifndef PNGPRIV_H +#define PNGPRIV_H + +/* Feature Test Macros. The following are defined here to ensure that correctly + * implemented libraries reveal the APIs libpng needs to build and hide those + * that are not needed and potentially damaging to the compilation. + * + * Feature Test Macros must be defined before any system header is included (see + * POSIX 1003.1 2.8.2 "POSIX Symbols." + * + * These macros only have an effect if the operating system supports either + * POSIX 1003.1 or C99, or both. On other operating systems (particularly + * Windows/Visual Studio) there is no effect; the OS specific tests below are + * still required (as of 2011-05-02.) + */ +#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */ + +#ifndef PNG_VERSION_INFO_ONLY +/* Standard library headers not required by png.h: */ +# include <stdlib.h> +# include <string.h> +#endif + +#define PNGLIB_BUILD /*libpng is being built, not used*/ + +/* If HAVE_CONFIG_H is defined during the build then the build system must + * provide an appropriate "config.h" file on the include path. The header file + * must provide definitions as required below (search for "HAVE_CONFIG_H"); + * see configure.ac for more details of the requirements. The macro + * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on + * 'configure'; define this macro to prevent the configure build including the + * configure generated config.h. Libpng is expected to compile without *any* + * special build system support on a reasonably ANSI-C compliant system. + */ +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> + + /* Pick up the definition of 'restrict' from config.h if it was read: */ +# define PNG_RESTRICT restrict +#endif + +/* To support symbol prefixing it is necessary to know *before* including png.h + * whether the fixed point (and maybe other) APIs are exported, because if they + * are not internal definitions may be required. This is handled below just + * before png.h is included, but load the configuration now if it is available. + */ +#ifndef PNGLCONF_H +# include "pnglibconf.h" +#endif + +/* Local renames may change non-exported API functions from png.h */ +#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H) +# include "pngprefix.h" +#endif + +#ifdef PNG_USER_CONFIG +# include "pngusr.h" + /* These should have been defined in pngusr.h */ +# ifndef PNG_USER_PRIVATEBUILD +# define PNG_USER_PRIVATEBUILD "Custom libpng build" +# endif +# ifndef PNG_USER_DLLFNAME_POSTFIX +# define PNG_USER_DLLFNAME_POSTFIX "Cb" +# endif +#endif + +/* Compile time options. + * ===================== + * In a multi-arch build the compiler may compile the code several times for the + * same object module, producing different binaries for different architectures. + * When this happens configure-time setting of the target host options cannot be + * done and this interferes with the handling of the ARM NEON optimizations, and + * possibly other similar optimizations. Put additional tests here; in general + * this is needed when the same option can be changed at both compile time and + * run time depending on the target OS (i.e. iOS vs Android.) + * + * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because + * this is not possible with certain compilers (Oracle SUN OS CC), as a result + * it is necessary to ensure that all extern functions that *might* be used + * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON__ + * below is one example of this behavior because it is controlled by the + * presence or not of -mfpu=neon on the GCC command line, it is possible to do + * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely + * do this. + */ +#ifndef PNG_ARM_NEON_OPT + /* ARM NEON optimizations are being controlled by the compiler settings, + * typically the target FPU. If the FPU has been set to NEON (-mfpu=neon + * with GCC) then the compiler will define __ARM_NEON__ and we can rely + * unconditionally on NEON instructions not crashing, otherwise we must + * disable use of NEON instructions. + * + * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they + * can only be turned on automatically if that is supported too. If + * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail + * to compile with an appropriate #error if ALIGNED_MEMORY has been turned + * off. + * + * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated + * __ARM_NEON__, so we check both variants. + * + * To disable ARM_NEON optimizations entirely, and skip compiling the + * associated assembler code, pass --enable-arm-neon=no to configure + * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS. + */ +# if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \ + defined(PNG_ALIGNED_MEMORY_SUPPORTED) +# define PNG_ARM_NEON_OPT 2 +# else +# define PNG_ARM_NEON_OPT 0 +# endif +#endif + +#if PNG_ARM_NEON_OPT > 0 + /* NEON optimizations are to be at least considered by libpng, so enable the + * callbacks to do this. + */ +# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon + + /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used + * if possible - if __ARM_NEON__ is set and the compiler version is not known + * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can + * be: + * + * 1 The intrinsics code (the default with __ARM_NEON__) + * 2 The hand coded assembler (the default without __ARM_NEON__) + * + * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however + * this is *NOT* supported and may cease to work even after a minor revision + * to libpng. It *is* valid to do this for testing purposes, e.g. speed + * testing or a new compiler, but the results should be communicated to the + * libpng implementation list for incorporation in the next minor release. + */ +# ifndef PNG_ARM_NEON_IMPLEMENTATION +# if defined(__ARM_NEON__) || defined(__ARM_NEON) +# if defined(__clang__) + /* At present it is unknown by the libpng developers which versions + * of clang support the intrinsics, however some or perhaps all + * versions do not work with the assembler so this may be + * irrelevant, so just use the default (do nothing here.) + */ +# elif defined(__GNUC__) + /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to + * work, so if this *is* GCC, or G++, look for a version >4.5 + */ +# if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6) +# define PNG_ARM_NEON_IMPLEMENTATION 2 +# endif /* no GNUC support */ +# endif /* __GNUC__ */ +# else /* !defined __ARM_NEON__ */ + /* The 'intrinsics' code simply won't compile without this -mfpu=neon: + */ +# define PNG_ARM_NEON_IMPLEMENTATION 2 +# endif /* __ARM_NEON__ */ +# endif /* !PNG_ARM_NEON_IMPLEMENTATION */ + +# ifndef PNG_ARM_NEON_IMPLEMENTATION + /* Use the intrinsics code by default. */ +# define PNG_ARM_NEON_IMPLEMENTATION 1 +# endif +#endif /* PNG_ARM_NEON_OPT > 0 */ + +/* Is this a build of a DLL where compilation of the object modules requires + * different preprocessor settings to those required for a simple library? If + * so PNG_BUILD_DLL must be set. + * + * If libpng is used inside a DLL but that DLL does not export the libpng APIs + * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a + * static library of libpng then link the DLL against that. + */ +#ifndef PNG_BUILD_DLL +# ifdef DLL_EXPORT + /* This is set by libtool when files are compiled for a DLL; libtool + * always compiles twice, even on systems where it isn't necessary. Set + * PNG_BUILD_DLL in case it is necessary: + */ +# define PNG_BUILD_DLL +# else +# ifdef _WINDLL + /* This is set by the Microsoft Visual Studio IDE in projects that + * build a DLL. It can't easily be removed from those projects (it + * isn't visible in the Visual Studio UI) so it is a fairly reliable + * indication that PNG_IMPEXP needs to be set to the DLL export + * attributes. + */ +# define PNG_BUILD_DLL +# else +# ifdef __DLL__ + /* This is set by the Borland C system when compiling for a DLL + * (as above.) + */ +# define PNG_BUILD_DLL +# else + /* Add additional compiler cases here. */ +# endif +# endif +# endif +#endif /* Setting PNG_BUILD_DLL if required */ + +/* See pngconf.h for more details: the builder of the library may set this on + * the command line to the right thing for the specific compilation system or it + * may be automagically set above (at present we know of no system where it does + * need to be set on the command line.) + * + * PNG_IMPEXP must be set here when building the library to prevent pngconf.h + * setting it to the "import" setting for a DLL build. + */ +#ifndef PNG_IMPEXP +# ifdef PNG_BUILD_DLL +# define PNG_IMPEXP PNG_DLL_EXPORT +# else + /* Not building a DLL, or the DLL doesn't require specific export + * definitions. + */ +# define PNG_IMPEXP +# endif +#endif + +/* No warnings for private or deprecated functions in the build: */ +#ifndef PNG_DEPRECATED +# define PNG_DEPRECATED +#endif +#ifndef PNG_PRIVATE +# define PNG_PRIVATE +#endif + +/* Symbol preprocessing support. + * + * To enable listing global, but internal, symbols the following macros should + * always be used to declare an extern data or function object in this file. + */ +#ifndef PNG_INTERNAL_DATA +# define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array +#endif + +#ifndef PNG_INTERNAL_FUNCTION +# define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\ + PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes) +#endif + +#ifndef PNG_INTERNAL_CALLBACK +# define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\ + PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\ + PNG_EMPTY attributes) +#endif + +/* If floating or fixed point APIs are disabled they may still be compiled + * internally. To handle this make sure they are declared as the appropriate + * internal extern function (otherwise the symbol prefixing stuff won't work and + * the functions will be used without definitions.) + * + * NOTE: although all the API functions are declared here they are not all + * actually built! Because the declarations are still made it is necessary to + * fake out types that they depend on. + */ +#ifndef PNG_FP_EXPORT +# ifndef PNG_FLOATING_POINT_SUPPORTED +# define PNG_FP_EXPORT(ordinal, type, name, args)\ + PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY); +# ifndef PNG_VERSION_INFO_ONLY + typedef struct png_incomplete png_double; + typedef png_double* png_doublep; + typedef const png_double* png_const_doublep; + typedef png_double** png_doublepp; +# endif +# endif +#endif +#ifndef PNG_FIXED_EXPORT +# ifndef PNG_FIXED_POINT_SUPPORTED +# define PNG_FIXED_EXPORT(ordinal, type, name, args)\ + PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY); +# endif +#endif + +#include "png.h" + +/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */ +#ifndef PNG_DLL_EXPORT +# define PNG_DLL_EXPORT +#endif + +/* This is a global switch to set the compilation for an installed system + * (a release build). It can be set for testing debug builds to ensure that + * they will compile when the build type is switched to RC or STABLE, the + * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE. Set this in CPPFLAGS + * with either: + * + * -DPNG_RELEASE_BUILD Turns on the release compile path + * -DPNG_RELEASE_BUILD=0 Turns it off + * or in your pngusr.h with + * #define PNG_RELEASE_BUILD=1 Turns on the release compile path + * #define PNG_RELEASE_BUILD=0 Turns it off + */ +#ifndef PNG_RELEASE_BUILD +# define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC) +#endif + +/* SECURITY and SAFETY: + * + * libpng is built with support for internal limits on image dimensions and + * memory usage. These are documented in scripts/pnglibconf.dfa of the + * source and recorded in the machine generated header file pnglibconf.h. + */ + +/* If you are running on a machine where you cannot allocate more + * than 64K of memory at once, uncomment this. While libpng will not + * normally need that much memory in a chunk (unless you load up a very + * large file), zlib needs to know how big of a chunk it can use, and + * libpng thus makes sure to check any memory allocation to verify it + * will fit into memory. + * + * zlib provides 'MAXSEG_64K' which, if defined, indicates the + * same limit and pngconf.h (already included) sets the limit + * if certain operating systems are detected. + */ +#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) +# define PNG_MAX_MALLOC_64K +#endif + +#ifndef PNG_UNUSED +/* Unused formal parameter warnings are silenced using the following macro + * which is expected to have no bad effects on performance (optimizing + * compilers will probably remove it entirely). Note that if you replace + * it with something other than whitespace, you must include the terminating + * semicolon. + */ +# define PNG_UNUSED(param) (void)param; +#endif + +/* Just a little check that someone hasn't tried to define something + * contradictory. + */ +#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K) +# undef PNG_ZBUF_SIZE +# define PNG_ZBUF_SIZE 65536L +#endif + +/* If warnings or errors are turned off the code is disabled or redirected here. + * From 1.5.4 functions have been added to allow very limited formatting of + * error and warning messages - this code will also be disabled here. + */ +#ifdef PNG_WARNINGS_SUPPORTED +# define PNG_WARNING_PARAMETERS(p) png_warning_parameters p; +#else +# define png_warning_parameter(p,number,string) ((void)0) +# define png_warning_parameter_unsigned(p,number,format,value) ((void)0) +# define png_warning_parameter_signed(p,number,format,value) ((void)0) +# define png_formatted_warning(pp,p,message) ((void)(pp)) +# define PNG_WARNING_PARAMETERS(p) +#endif +#ifndef PNG_ERROR_TEXT_SUPPORTED +# define png_fixed_error(s1,s2) png_err(s1) +#endif + +/* C allows up-casts from (void*) to any pointer and (const void*) to any + * pointer to a const object. C++ regards this as a type error and requires an + * explicit, static, cast and provides the static_cast<> rune to ensure that + * const is not cast away. + */ +#ifdef __cplusplus +# define png_voidcast(type, value) static_cast<type>(value) +# define png_constcast(type, value) const_cast<type>(value) +# define png_aligncast(type, value) \ + static_cast<type>(static_cast<void*>(value)) +# define png_aligncastconst(type, value) \ + static_cast<type>(static_cast<const void*>(value)) +#else +# define png_voidcast(type, value) (value) +# define png_constcast(type, value) ((type)(value)) +# define png_aligncast(type, value) ((void*)(value)) +# define png_aligncastconst(type, value) ((const void*)(value)) +#endif /* __cplusplus */ + +/* Some fixed point APIs are still required even if not exported because + * they get used by the corresponding floating point APIs. This magic + * deals with this: + */ +#ifdef PNG_FIXED_POINT_SUPPORTED +# define PNGFAPI PNGAPI +#else +# define PNGFAPI /* PRIVATE */ +#endif + +#ifndef PNG_VERSION_INFO_ONLY +/* Other defines specific to compilers can go here. Try to keep + * them inside an appropriate ifdef/endif pair for portability. + */ +#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\ + defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) + /* png.c requires the following ANSI-C constants if the conversion of + * floating point to ASCII is implemented therein: + * + * DBL_DIG Maximum number of decimal digits (can be set to any constant) + * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value) + * DBL_MAX Maximum floating point number (can be set to an arbitrary value) + */ +# include <float.h> + +# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \ + defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC) + /* We need to check that <math.h> hasn't already been included earlier + * as it seems it doesn't agree with <fp.h>, yet we should really use + * <fp.h> if possible. + */ +# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__) +# include <fp.h> +# endif +# else +# include <math.h> +# endif +# if defined(_AMIGA) && defined(__SASC) && defined(_M68881) + /* Amiga SAS/C: We must include builtin FPU functions when compiling using + * MATH=68881 + */ +# include <m68881.h> +# endif +#endif + +/* This provides the non-ANSI (far) memory allocation routines. */ +#if defined(__TURBOC__) && defined(__MSDOS__) +# include <mem.h> +# include <alloc.h> +#endif + +#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \ + defined(_WIN32) || defined(__WIN32__) +# include <windows.h> /* defines _WINDOWS_ macro */ +#endif +#endif /* PNG_VERSION_INFO_ONLY */ + +/* Moved here around 1.5.0beta36 from pngconf.h */ +/* Users may want to use these so they are not private. Any library + * functions that are passed far data must be model-independent. + */ + +/* Memory model/platform independent fns */ +#ifndef PNG_ABORT +# ifdef _WINDOWS_ +# define PNG_ABORT() ExitProcess(0) +# else +# define PNG_ABORT() abort() +# endif +#endif + +/* These macros may need to be architecture dependent. */ +#define PNG_ALIGN_NONE 0 /* do not use data alignment */ +#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */ +#ifdef offsetof +# define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */ +#else +# define PNG_ALIGN_OFFSET -1 /* prevent the use of this */ +#endif +#define PNG_ALIGN_SIZE 3 /* use sizeof to determine alignment */ + +#ifndef PNG_ALIGN_TYPE + /* Default to using aligned access optimizations and requiring alignment to a + * multiple of the data type size. Override in a compiler specific fashion + * if necessary by inserting tests here: + */ +# define PNG_ALIGN_TYPE PNG_ALIGN_SIZE +#endif + +#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE + /* This is used because in some compiler implementations non-aligned + * structure members are supported, so the offsetof approach below fails. + * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access + * is good for performance. Do not do this unless you have tested the result + * and understand it. + */ +# define png_alignof(type) (sizeof (type)) +#else +# if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET +# define png_alignof(type) offsetof(struct{char c; type t;}, t) +# else +# if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS +# define png_alignof(type) (1) +# endif + /* Else leave png_alignof undefined to prevent use thereof */ +# endif +#endif + +/* This implicitly assumes alignment is always to a power of 2. */ +#ifdef png_alignof +# define png_isaligned(ptr, type)\ + ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0) +#else +# define png_isaligned(ptr, type) 0 +#endif + +/* End of memory model/platform independent support */ +/* End of 1.5.0beta36 move from pngconf.h */ + +/* CONSTANTS and UTILITY MACROS + * These are used internally by libpng and not exposed in the API + */ + +/* Various modes of operation. Note that after an init, mode is set to + * zero automatically when the structure is created. Three of these + * are defined in png.h because they need to be visible to applications + * that call png_set_unknown_chunk(). + */ +/* #define PNG_HAVE_IHDR 0x01 (defined in png.h) */ +/* #define PNG_HAVE_PLTE 0x02 (defined in png.h) */ +#define PNG_HAVE_IDAT 0x04 +/* #define PNG_AFTER_IDAT 0x08 (defined in png.h) */ +#define PNG_HAVE_IEND 0x10 + /* 0x20 (unused) */ + /* 0x40 (unused) */ + /* 0x80 (unused) */ +#define PNG_HAVE_CHUNK_HEADER 0x100 +#define PNG_WROTE_tIME 0x200 +#define PNG_WROTE_INFO_BEFORE_PLTE 0x400 +#define PNG_BACKGROUND_IS_GRAY 0x800 +#define PNG_HAVE_PNG_SIGNATURE 0x1000 +#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */ + /* 0x4000 (unused) */ +#define PNG_IS_READ_STRUCT 0x8000 /* Else is a write struct */ + +/* Flags for the transformations the PNG library does on the image data */ +#define PNG_BGR 0x0001 +#define PNG_INTERLACE 0x0002 +#define PNG_PACK 0x0004 +#define PNG_SHIFT 0x0008 +#define PNG_SWAP_BYTES 0x0010 +#define PNG_INVERT_MONO 0x0020 +#define PNG_QUANTIZE 0x0040 +#define PNG_COMPOSE 0x0080 /* Was PNG_BACKGROUND */ +#define PNG_BACKGROUND_EXPAND 0x0100 +#define PNG_EXPAND_16 0x0200 /* Added to libpng 1.5.2 */ +#define PNG_16_TO_8 0x0400 /* Becomes 'chop' in 1.5.4 */ +#define PNG_RGBA 0x0800 +#define PNG_EXPAND 0x1000 +#define PNG_GAMMA 0x2000 +#define PNG_GRAY_TO_RGB 0x4000 +#define PNG_FILLER 0x8000 +#define PNG_PACKSWAP 0x10000 +#define PNG_SWAP_ALPHA 0x20000 +#define PNG_STRIP_ALPHA 0x40000 +#define PNG_INVERT_ALPHA 0x80000 +#define PNG_USER_TRANSFORM 0x100000 +#define PNG_RGB_TO_GRAY_ERR 0x200000 +#define PNG_RGB_TO_GRAY_WARN 0x400000 +#define PNG_RGB_TO_GRAY 0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */ +#define PNG_ENCODE_ALPHA 0x800000 /* Added to libpng-1.5.4 */ +#define PNG_ADD_ALPHA 0x1000000 /* Added to libpng-1.2.7 */ +#define PNG_EXPAND_tRNS 0x2000000 /* Added to libpng-1.2.9 */ +#define PNG_SCALE_16_TO_8 0x4000000 /* Added to libpng-1.5.4 */ + /* 0x8000000 unused */ + /* 0x10000000 unused */ + /* 0x20000000 unused */ + /* 0x40000000 unused */ +/* Flags for png_create_struct */ +#define PNG_STRUCT_PNG 0x0001 +#define PNG_STRUCT_INFO 0x0002 + +/* Flags for the png_ptr->flags rather than declaring a byte for each one */ +#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001 +#define PNG_FLAG_ZSTREAM_INITIALIZED 0x0002 /* Added to libpng-1.6.0 */ + /* 0x0004 unused */ +#define PNG_FLAG_ZSTREAM_ENDED 0x0008 /* Added to libpng-1.6.0 */ + /* 0x0010 unused */ + /* 0x0020 unused */ +#define PNG_FLAG_ROW_INIT 0x0040 +#define PNG_FLAG_FILLER_AFTER 0x0080 +#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100 +#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200 +#define PNG_FLAG_CRC_CRITICAL_USE 0x0400 +#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800 +#define PNG_FLAG_ASSUME_sRGB 0x1000 /* Added to libpng-1.5.4 */ +#define PNG_FLAG_OPTIMIZE_ALPHA 0x2000 /* Added to libpng-1.5.4 */ +#define PNG_FLAG_DETECT_UNINITIALIZED 0x4000 /* Added to libpng-1.5.4 */ +/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000 */ +/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000 */ +#define PNG_FLAG_LIBRARY_MISMATCH 0x20000 +#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000 +#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000 +#define PNG_FLAG_BENIGN_ERRORS_WARN 0x100000 /* Added to libpng-1.4.0 */ +#define PNG_FLAG_APP_WARNINGS_WARN 0x200000 /* Added to libpng-1.6.0 */ +#define PNG_FLAG_APP_ERRORS_WARN 0x400000 /* Added to libpng-1.6.0 */ + /* 0x800000 unused */ + /* 0x1000000 unused */ + /* 0x2000000 unused */ + /* 0x4000000 unused */ + /* 0x8000000 unused */ + /* 0x10000000 unused */ + /* 0x20000000 unused */ + /* 0x40000000 unused */ + +#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \ + PNG_FLAG_CRC_ANCILLARY_NOWARN) + +#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \ + PNG_FLAG_CRC_CRITICAL_IGNORE) + +#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \ + PNG_FLAG_CRC_CRITICAL_MASK) + +/* Save typing and make code easier to understand */ + +#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \ + abs((int)((c1).green) - (int)((c2).green)) + \ + abs((int)((c1).blue) - (int)((c2).blue))) + +/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255 + * by dividing by 257 *with rounding*. This macro is exact for the given range. + * See the discourse in pngrtran.c png_do_scale_16_to_8. The values in the + * macro were established by experiment (modifying the added value). The macro + * has a second variant that takes a value already scaled by 255 and divides by + * 65535 - this has a maximum error of .502. Over the range 0..65535*65535 it + * only gives off-by-one errors and only for 0.5% (1 in 200) of the values. + */ +#define PNG_DIV65535(v24) (((v24) + 32895) >> 16) +#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255) + +/* Added to libpng-1.2.6 JB */ +#define PNG_ROWBYTES(pixel_bits, width) \ + ((pixel_bits) >= 8 ? \ + ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \ + (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) ) + +/* PNG_OUT_OF_RANGE returns true if value is outside the range + * ideal-delta..ideal+delta. Each argument is evaluated twice. + * "ideal" and "delta" should be constants, normally simple + * integers, "value" a variable. Added to libpng-1.2.6 JB + */ +#define PNG_OUT_OF_RANGE(value, ideal, delta) \ + ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) ) + +/* Conversions between fixed and floating point, only defined if + * required (to make sure the code doesn't accidentally use float + * when it is supposedly disabled.) + */ +#ifdef PNG_FLOATING_POINT_SUPPORTED +/* The floating point conversion can't overflow, though it can and + * does lose accuracy relative to the original fixed point value. + * In practice this doesn't matter because png_fixed_point only + * stores numbers with very low precision. The png_ptr and s + * arguments are unused by default but are there in case error + * checking becomes a requirement. + */ +#define png_float(png_ptr, fixed, s) (.00001 * (fixed)) + +/* The fixed point conversion performs range checking and evaluates + * its argument multiple times, so must be used with care. The + * range checking uses the PNG specification values for a signed + * 32-bit fixed point value except that the values are deliberately + * rounded-to-zero to an integral value - 21474 (21474.83 is roughly + * (2^31-1) * 100000). 's' is a string that describes the value being + * converted. + * + * NOTE: this macro will raise a png_error if the range check fails, + * therefore it is normally only appropriate to use this on values + * that come from API calls or other sources where an out of range + * error indicates a programming error, not a data error! + * + * NOTE: by default this is off - the macro is not used - because the + * function call saves a lot of code. + */ +#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED +#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\ + ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0)) +#endif +/* else the corresponding function is defined below, inside the scope of the + * cplusplus test. + */ +#endif + +/* Constants for known chunk types. If you need to add a chunk, define the name + * here. For historical reasons these constants have the form png_<name>; i.e. + * the prefix is lower case. Please use decimal values as the parameters to + * match the ISO PNG specification and to avoid relying on the C locale + * interpretation of character values. + * + * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values + * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string + * to be generated if required. + * + * PNG_32b correctly produces a value shifted by up to 24 bits, even on + * architectures where (int) is only 16 bits. + */ +#define PNG_32b(b,s) ((png_uint_32)(b) << (s)) +#define PNG_U32(b1,b2,b3,b4) \ + (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0)) + +/* Constants for known chunk types. + * + * MAINTAINERS: If you need to add a chunk, define the name here. + * For historical reasons these constants have the form png_<name>; i.e. + * the prefix is lower case. Please use decimal values as the parameters to + * match the ISO PNG specification and to avoid relying on the C locale + * interpretation of character values. Please keep the list sorted. + * + * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk + * type. In fact the specification does not express chunk types this way, + * however using a 32-bit value means that the chunk type can be read from the + * stream using exactly the same code as used for a 32-bit unsigned value and + * can be examined far more efficiently (using one arithmetic compare). + * + * Prior to 1.5.6 the chunk type constants were expressed as C strings. The + * libpng API still uses strings for 'unknown' chunks and a macro, + * PNG_STRING_FROM_CHUNK, allows a string to be generated if required. Notice + * that for portable code numeric values must still be used; the string "IHDR" + * is not portable and neither is PNG_U32('I', 'H', 'D', 'R'). + * + * In 1.7.0 the definitions will be made public in png.h to avoid having to + * duplicate the same definitions in application code. + */ +#define png_IDAT PNG_U32( 73, 68, 65, 84) +#define png_IEND PNG_U32( 73, 69, 78, 68) +#define png_IHDR PNG_U32( 73, 72, 68, 82) +#define png_PLTE PNG_U32( 80, 76, 84, 69) +#define png_bKGD PNG_U32( 98, 75, 71, 68) +#define png_cHRM PNG_U32( 99, 72, 82, 77) +#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */ +#define png_gAMA PNG_U32(103, 65, 77, 65) +#define png_gIFg PNG_U32(103, 73, 70, 103) +#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */ +#define png_gIFx PNG_U32(103, 73, 70, 120) +#define png_hIST PNG_U32(104, 73, 83, 84) +#define png_iCCP PNG_U32(105, 67, 67, 80) +#define png_iTXt PNG_U32(105, 84, 88, 116) +#define png_oFFs PNG_U32(111, 70, 70, 115) +#define png_pCAL PNG_U32(112, 67, 65, 76) +#define png_pHYs PNG_U32(112, 72, 89, 115) +#define png_sBIT PNG_U32(115, 66, 73, 84) +#define png_sCAL PNG_U32(115, 67, 65, 76) +#define png_sPLT PNG_U32(115, 80, 76, 84) +#define png_sRGB PNG_U32(115, 82, 71, 66) +#define png_sTER PNG_U32(115, 84, 69, 82) +#define png_tEXt PNG_U32(116, 69, 88, 116) +#define png_tIME PNG_U32(116, 73, 77, 69) +#define png_tRNS PNG_U32(116, 82, 78, 83) +#define png_zTXt PNG_U32(122, 84, 88, 116) + +/* The following will work on (signed char*) strings, whereas the get_uint_32 + * macro will fail on top-bit-set values because of the sign extension. + */ +#define PNG_CHUNK_FROM_STRING(s)\ + PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3]) + +/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is + * signed and the argument is a (char[]) This macro will fail miserably on + * systems where (char) is more than 8 bits. + */ +#define PNG_STRING_FROM_CHUNK(s,c)\ + (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \ + ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\ + ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \ + ((char*)(s))[3]=(char)((c & 0xff))) + +/* Do the same but terminate with a null character. */ +#define PNG_CSTRING_FROM_CHUNK(s,c)\ + (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0) + +/* Test on flag values as defined in the spec (section 5.4): */ +#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29)) +#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c)) +#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21)) +#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13)) +#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5)) + +/* Gamma values (new at libpng-1.5.4): */ +#define PNG_GAMMA_MAC_OLD 151724 /* Assume '1.8' is really 2.2/1.45! */ +#define PNG_GAMMA_MAC_INVERSE 65909 +#define PNG_GAMMA_sRGB_INVERSE 45455 + +/* Almost everything below is C specific; the #defines above can be used in + * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot. + */ +#ifndef PNG_VERSION_INFO_ONLY + +#include "pngstruct.h" +#include "pnginfo.h" + +/* Validate the include paths - the include path used to generate pnglibconf.h + * must match that used in the build, or we must be using pnglibconf.h.prebuilt: + */ +#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM +# error ZLIB_VERNUM != PNG_ZLIB_VERNUM \ + "-I (include path) error: see the notes in pngpriv.h" + /* This means that when pnglibconf.h was built the copy of zlib.h that it + * used is not the same as the one being used here. Because the build of + * libpng makes decisions to use inflateInit2 and inflateReset2 based on the + * zlib version number and because this affects handling of certain broken + * PNG files the -I directives must match. + * + * The most likely explanation is that you passed a -I in CFLAGS. This will + * not work; all the preprocessor directories and in particular all the -I + * directives must be in CPPFLAGS. + */ +#endif + +/* This is used for 16-bit gamma tables -- only the top level pointers are + * const; this could be changed: + */ +typedef const png_uint_16p * png_const_uint_16pp; + +/* Added to libpng-1.5.7: sRGB conversion tables */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]); + /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value, + * 0..65535. This table gives the closest 16-bit answers (no errors). + */ +#endif + +PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]); +PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]); + +#define PNG_sRGB_FROM_LINEAR(linear) \ + ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \ + + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))) + /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB + * encoded value with maximum error 0.646365. Note that the input is not a + * 16-bit value; it has been multiplied by 255! */ +#endif /* SIMPLIFIED_READ/WRITE */ + + +/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Internal functions; these are not exported from a DLL however because they + * are used within several of the C source files they have to be C extern. + * + * All of these functions must be declared with PNG_INTERNAL_FUNCTION. + */ + +/* Zlib support */ +#define PNG_UNEXPECTED_ZLIB_RETURN (-7) +PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret), + PNG_EMPTY); + /* Used by the zlib handling functions to ensure that z_stream::msg is always + * set before they return. + */ + +#ifdef PNG_WRITE_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr, + png_compression_bufferp *list),PNG_EMPTY); + /* Free the buffer list used by the compressed write code. */ +#endif + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ + !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \ + (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \ + defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \ + (defined(PNG_sCAL_SUPPORTED) && \ + defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)) +PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr, + double fp, png_const_charp text),PNG_EMPTY); +#endif + +/* Check the user version string for compatibility, returns false if the version + * numbers aren't compatible. + */ +PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr, + png_const_charp user_png_ver),PNG_EMPTY); + +/* Internal base allocator - no messages, NULL on failure to allocate. This + * does, however, call the application provided allocator and that could call + * png_error (although that would be a bug in the application implementation.) + */ +PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr, + png_alloc_size_t size),PNG_ALLOCATED); + +#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\ + defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) +/* Internal array allocator, outputs no error or warning messages on failure, + * just returns NULL. + */ +PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr, + int nelements, size_t element_size),PNG_ALLOCATED); + +/* The same but an existing array is extended by add_elements. This function + * also memsets the new elements to 0 and copies the old elements. The old + * array is not freed or altered. + */ +PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr, + png_const_voidp array, int old_elements, int add_elements, + size_t element_size),PNG_ALLOCATED); +#endif /* text, sPLT or unknown chunks */ + +/* Magic to create a struct when there is no struct to call the user supplied + * memory allocators. Because error handling has not been set up the memory + * handlers can't safely call png_error, but this is an obscure and undocumented + * restriction so libpng has to assume that the 'free' handler, at least, might + * call png_error. + */ +PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn, + png_free_ptr free_fn),PNG_ALLOCATED); + +/* Free memory from internal libpng struct */ +PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr), + PNG_EMPTY); + +/* Free an allocated jmp_buf (always succeeds) */ +PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY); + +/* Function to allocate memory for zlib. PNGAPI is disallowed. */ +PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size), + PNG_ALLOCATED); + +/* Function to free memory for zlib. PNGAPI is disallowed. */ +PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY); + +/* Next four functions are used internally as callbacks. PNGCBAPI is required + * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to + * PNGCBAPI at 1.5.0 + */ + +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr, + png_bytep data, png_size_t length),PNG_EMPTY); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr, + png_bytep buffer, png_size_t length),PNG_EMPTY); +#endif + +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr, + png_bytep data, png_size_t length),PNG_EMPTY); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_STDIO_SUPPORTED +PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr), + PNG_EMPTY); +# endif +#endif + +/* Reset the CRC variable */ +PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY); + +/* Write the "data" buffer to whatever output you are using */ +PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr, + png_const_bytep data, png_size_t length),PNG_EMPTY); + +/* Read and check the PNG file signature */ +PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); + +/* Read the chunk header (length + type name) */ +PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr), + PNG_EMPTY); + +/* Read data from whatever input you are using into the "data" buffer */ +PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data, + png_size_t length),PNG_EMPTY); + +/* Read bytes into buf, and update png_ptr->crc */ +PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf, + png_uint_32 length),PNG_EMPTY); + +/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */ +PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr, + png_uint_32 skip),PNG_EMPTY); + +/* Read the CRC from the file and compare it to the libpng calculated CRC */ +PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY); + +/* Calculate the CRC over a section of data. Note that we are only + * passing a maximum of 64K on systems that have this as a memory limit, + * since this is the maximum buffer size we can specify. + */ +PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr, + png_const_bytep ptr, png_size_t length),PNG_EMPTY); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY); +#endif + +/* Write various chunks */ + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. + */ +PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, + int compression_method, int filter_method, int interlace_method),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr, + png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr, + png_const_bytep row_data, png_alloc_size_t row_data_length, int flush), + PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY); + +#ifdef PNG_WRITE_gAMA_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr, + png_fixed_point file_gamma),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr, + png_const_color_8p sbit, int color_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_cHRM_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr, + const png_xy *xy), PNG_EMPTY); + /* The xy value must have been previously validated */ +#endif + +#ifdef PNG_WRITE_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr, + int intent),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr, + png_const_charp name, png_const_bytep profile), PNG_EMPTY); + /* The profile must have been previously validated for correctness, the + * length comes from the first four bytes. Only the base, deflate, + * compression is supported. + */ +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr, + png_const_sPLT_tp palette),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_tRNS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr, + png_const_bytep trans, png_const_color_16p values, int number, + int color_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_bKGD_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr, + png_const_color_16p values, int color_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr, + png_const_uint_16p hist, int num_hist),PNG_EMPTY); +#endif + +/* Chunks that have keywords */ +#ifdef PNG_WRITE_tEXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr, + png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_zTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp + key, png_const_charp text, int compression),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_iTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr, + int compression, png_const_charp key, png_const_charp lang, + png_const_charp lang_key, png_const_charp text),PNG_EMPTY); +#endif + +#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */ +PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr, + png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr, + png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_pCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr, + png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, + png_const_charp units, png_charpp params),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr, + png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, + int unit_type),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_tIME_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr, + png_const_timep mod_time),PNG_EMPTY); +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr, + int unit, png_const_charp width, png_const_charp height),PNG_EMPTY); +#endif + +/* Called when finished processing a row of data */ +PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr), + PNG_EMPTY); + +/* Internal use only. Called before first row of data */ +PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr), + PNG_EMPTY); + +/* Combine a row of data, dealing with alpha, etc. if requested. 'row' is an + * array of png_ptr->width pixels. If the image is not interlaced or this + * is the final pass this just does a memcpy, otherwise the "display" flag + * is used to determine whether to copy pixels that are not in the current pass. + * + * Because 'png_do_read_interlace' (below) replicates pixels this allows this + * function to achieve the documented 'blocky' appearance during interlaced read + * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row' + * are not changed if they are not in the current pass, when display is 0. + * + * 'display' must be 0 or 1, otherwise the memcpy will be done regardless. + * + * The API always reads from the png_struct row buffer and always assumes that + * it is full width (png_do_read_interlace has already been called.) + * + * This function is only ever used to write to row buffers provided by the + * caller of the relevant libpng API and the row must have already been + * transformed by the read transformations. + * + * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed + * bitmasks for use within the code, otherwise runtime generated masks are used. + * The default is compile time masks. + */ +#ifndef PNG_USE_COMPILE_TIME_MASKS +# define PNG_USE_COMPILE_TIME_MASKS 1 +#endif +PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr, + png_bytep row, int display),PNG_EMPTY); + +#ifdef PNG_READ_INTERLACING_SUPPORTED +/* Expand an interlaced row: the 'row_info' describes the pass data that has + * been read in and must correspond to the pixels in 'row', the pixels are + * expanded (moved apart) in 'row' to match the final layout, when doing this + * the pixels are *replicated* to the intervening space. This is essential for + * the correct operation of png_combine_row, above. + */ +PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info, + png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY); +#endif + +/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */ + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +/* Grab pixels out of a row for an interlaced pass */ +PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info, + png_bytep row, int pass),PNG_EMPTY); +#endif + +/* Unfilter a row: check the filter value before calling this, there is no point + * calling it for PNG_FILTER_VALUE_NONE. + */ +PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop + row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); + +/* Choose the best filter to use and filter the row data */ +PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr, + png_row_infop row_info),PNG_EMPTY); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr, + png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY); + /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer + * is NULL the function checks, instead, for the end of the stream. In this + * case a benign error will be issued if the stream end is not found or if + * extra data has to be consumed. + */ +PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr), + PNG_EMPTY); + /* This cleans up when the IDAT LZ stream does not end when the last image + * byte is read; there is still some pending input. + */ + +PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr), + PNG_EMPTY); + /* Finish a row while reading, dealing with interlacing passes, etc. */ +#endif /* SEQUENTIAL_READ */ + +/* Initialize the row buffers, etc. */ +PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY); + +#if PNG_ZLIB_VERNUM >= 0x1240 +PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush), + PNG_EMPTY); +# define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush) +#else /* Zlib < 1.2.4 */ +# define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush) +#endif /* Zlib < 1.2.4 */ + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* Optional call to update the users info structure */ +PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +#endif + +/* Shared transform functions, defined in pngtran.c */ +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info, + png_bytep row, int at_start),PNG_EMPTY); +#endif + +#ifdef PNG_16BIT_SUPPORTED +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ + defined(PNG_WRITE_PACKSWAP_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info, + png_bytep row),PNG_EMPTY); +#endif + +/* The following decodes the appropriate chunks, and does error correction, + * then calls the appropriate callback for the chunk if it is valid. + */ + +/* Decode the IHDR chunk */ +PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); + +#ifdef PNG_READ_bKGD_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif /* READ_iCCP */ + +#ifdef PNG_READ_iTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif /* READ_sPLT */ + +#ifdef PNG_READ_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +#endif + +PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr, + png_uint_32 chunk_name),PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY); + /* This is the function that gets called for unknown chunks. The 'keep' + * argument is either non-zero for a known chunk that has been set to be + * handled as unknown or zero for an unknown chunk. By default the function + * just skips the chunk or errors out if it is critical. + */ + +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\ + defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) +PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling, + (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY); + /* Exactly as the API png_handle_as_unknown() except that the argument is a + * 32-bit chunk name, not a string. + */ +#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */ + +/* Handle the transformations for reading and writing */ +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr, + png_row_infop row_info),PNG_EMPTY); +#endif +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr, + png_row_infop row_info),PNG_EMPTY); +#endif + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr), + PNG_EMPTY); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr, + png_bytep buffer, png_size_t buffer_length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr, + png_bytep buffer, png_size_t buffer_length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr, + png_bytep row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr), + PNG_EMPTY); +# ifdef PNG_READ_tEXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +# endif +# ifdef PNG_READ_zTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +# endif +# ifdef PNG_READ_iTXt_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr, + png_inforp info_ptr, png_uint_32 length),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr, + png_inforp info_ptr),PNG_EMPTY); +# endif + +#endif /* PROGRESSIVE_READ */ + +/* Added at libpng version 1.6.0 */ +#ifdef PNG_GAMMA_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY); + /* Set the colorspace gamma with a value provided by the application or by + * the gAMA chunk on read. The value will override anything set by an ICC + * profile. + */ + +PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr, + png_inforp info_ptr), PNG_EMPTY); + /* Synchronize the info 'valid' flags with the colorspace */ + +PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr, + png_inforp info_ptr), PNG_EMPTY); + /* Copy the png_struct colorspace to the info_struct and call the above to + * synchronize the flags. Checks for NULL info_ptr and does nothing. + */ +#endif + +/* Added at libpng version 1.4.0 */ +#ifdef PNG_COLORSPACE_SUPPORTED +/* These internal functions are for maintaining the colorspace structure within + * a png_info or png_struct (or, indeed, both). + */ +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities, + (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy, + int preferred), PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints, + (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ, + int preferred), PNG_EMPTY); + +#ifdef PNG_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr, + png_colorspacerp colorspace, int intent), PNG_EMPTY); + /* This does set the colorspace gAMA and cHRM values too, but doesn't set the + * flags to write them, if it returns false there was a problem and an error + * message has already been output (but the colorspace may still need to be + * synced to record the invalid flag). + */ +#endif /* sRGB */ + +#ifdef PNG_iCCP_SUPPORTED +PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length, png_const_bytep profile, int color_type), + PNG_EMPTY); + /* The 'name' is used for information only */ + +/* Routines for checking parts of an ICC profile. */ +PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length), PNG_EMPTY); +PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length, + png_const_bytep profile /* first 132 bytes only */, int color_type), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr, + png_colorspacerp colorspace, png_const_charp name, + png_uint_32 profile_length, + png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY); +#ifdef PNG_sRGB_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,( + png_const_structrp png_ptr, png_colorspacerp colorspace, + png_const_bytep profile, uLong adler), PNG_EMPTY); + /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may + * be zero to indicate that it is not available. It is used, if provided, + * as a fast check on the profile when checking to see if it is sRGB. + */ +#endif +#endif /* iCCP */ + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients, + (png_structrp png_ptr), PNG_EMPTY); + /* Set the rgb_to_gray coefficients from the colorspace Y values */ +#endif /* READ_RGB_TO_GRAY */ +#endif /* COLORSPACE */ + +/* Added at libpng version 1.4.0 */ +PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type),PNG_EMPTY); + +/* Added at libpng version 1.5.10 */ +#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ + defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes, + (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY); +#endif + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) +PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr, + png_const_charp name),PNG_NORETURN); +#endif + +/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite + * the end. Always leaves the buffer nul terminated. Never errors out (and + * there is no error code.) + */ +PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize, + size_t pos, png_const_charp string),PNG_EMPTY); + +/* Various internal functions to handle formatted warning messages, currently + * only implemented for warnings. + */ +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED) +/* Utility to dump an unsigned value into a buffer, given a start pointer and + * and end pointer (which should point just *beyond* the end of the buffer!) + * Returns the pointer to the start of the formatted string. This utility only + * does unsigned values. + */ +PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start, + png_charp end, int format, png_alloc_size_t number),PNG_EMPTY); + +/* Convenience macro that takes an array: */ +#define PNG_FORMAT_NUMBER(buffer,format,number) \ + png_format_number(buffer, buffer + (sizeof buffer), format, number) + +/* Suggested size for a number buffer (enough for 64 bits and a sign!) */ +#define PNG_NUMBER_BUFFER_SIZE 24 + +/* These are the integer formats currently supported, the name is formed from + * the standard printf(3) format string. + */ +#define PNG_NUMBER_FORMAT_u 1 /* chose unsigned API! */ +#define PNG_NUMBER_FORMAT_02u 2 +#define PNG_NUMBER_FORMAT_d 1 /* chose signed API! */ +#define PNG_NUMBER_FORMAT_02d 2 +#define PNG_NUMBER_FORMAT_x 3 +#define PNG_NUMBER_FORMAT_02x 4 +#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */ +#endif + +#ifdef PNG_WARNINGS_SUPPORTED +/* New defines and members adding in libpng-1.5.4 */ +# define PNG_WARNING_PARAMETER_SIZE 32 +# define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */ + +/* An l-value of this type has to be passed to the APIs below to cache the + * values of the parameters to a formatted warning message. + */ +typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][ + PNG_WARNING_PARAMETER_SIZE]; + +PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p, + int number, png_const_charp string),PNG_EMPTY); + /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters, + * including the trailing '\0'. + */ +PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned, + (png_warning_parameters p, int number, int format, png_alloc_size_t value), + PNG_EMPTY); + /* Use png_alloc_size_t because it is an unsigned type as big as any we + * need to output. Use the following for a signed value. + */ +PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed, + (png_warning_parameters p, int number, int format, png_int_32 value), + PNG_EMPTY); + +PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr, + png_warning_parameters p, png_const_charp message),PNG_EMPTY); + /* 'message' follows the X/Open approach of using @1, @2 to insert + * parameters previously supplied using the above functions. Errors in + * specifying the parameters will simply result in garbage substitutions. + */ +#endif + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +/* Application errors (new in 1.6); use these functions (declared below) for + * errors in the parameters or order of API function calls on read. The + * 'warning' should be used for an error that can be handled completely; the + * 'error' for one which can be handled safely but which may lose application + * information or settings. + * + * By default these both result in a png_error call prior to release, while in a + * released version the 'warning' is just a warning. However if the application + * explicitly disables benign errors (explicitly permitting the code to lose + * information) they both turn into warnings. + * + * If benign errors aren't supported they end up as the corresponding base call + * (png_warning or png_error.) + */ +PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr, + png_const_charp message),PNG_EMPTY); + /* The application provided invalid parameters to an API function or called + * an API function at the wrong time, libpng can completely recover. + */ + +PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr, + png_const_charp message),PNG_EMPTY); + /* As above but libpng will ignore the call, or attempt some other partial + * recovery from the error. + */ +#else +# define png_app_warning(pp,s) png_warning(pp,s) +# define png_app_error(pp,s) png_error(pp,s) +#endif + +PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr, + png_const_charp message, int error),PNG_EMPTY); + /* Report a recoverable issue in chunk data. On read this is used to report + * a problem found while reading a particular chunk and the + * png_chunk_benign_error or png_chunk_warning function is used as + * appropriate. On write this is used to report an error that comes from + * data set via an application call to a png_set_ API and png_app_error or + * png_app_warning is used as appropriate. + * + * The 'error' parameter must have one of the following values: + */ +#define PNG_CHUNK_WARNING 0 /* never an error */ +#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */ +#define PNG_CHUNK_ERROR 2 /* always an error */ + +/* ASCII to FP interfaces, currently only implemented if sCAL + * support is required. + */ +#if defined(PNG_sCAL_SUPPORTED) +/* MAX_DIGITS is actually the maximum number of characters in an sCAL + * width or height, derived from the precision (number of significant + * digits - a build time settable option) and assumptions about the + * maximum ridiculous exponent. + */ +#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/) + +#ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr, + png_charp ascii, png_size_t size, double fp, unsigned int precision), + PNG_EMPTY); +#endif /* FLOATING_POINT */ + +#ifdef PNG_FIXED_POINT_SUPPORTED +PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr, + png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY); +#endif /* FIXED_POINT */ +#endif /* sCAL */ + +#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) +/* An internal API to validate the format of a floating point number. + * The result is the index of the next character. If the number is + * not valid it will be the index of a character in the supposed number. + * + * The format of a number is defined in the PNG extensions specification + * and this API is strictly conformant to that spec, not anyone elses! + * + * The format as a regular expression is: + * + * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)? + * + * or: + * + * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)? + * + * The complexity is that either integer or fraction must be present and the + * fraction is permitted to have no digits only if the integer is present. + * + * NOTE: The dangling E problem. + * There is a PNG valid floating point number in the following: + * + * PNG floating point numbers are not greedy. + * + * Working this out requires *TWO* character lookahead (because of the + * sign), the parser does not do this - it will fail at the 'r' - this + * doesn't matter for PNG sCAL chunk values, but it requires more care + * if the value were ever to be embedded in something more complex. Use + * ANSI-C strtod if you need the lookahead. + */ +/* State table for the parser. */ +#define PNG_FP_INTEGER 0 /* before or in integer */ +#define PNG_FP_FRACTION 1 /* before or in fraction */ +#define PNG_FP_EXPONENT 2 /* before or in exponent */ +#define PNG_FP_STATE 3 /* mask for the above */ +#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */ +#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */ +#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */ +#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */ +#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */ + +/* These three values don't affect the parser. They are set but not used. + */ +#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */ +#define PNG_FP_NEGATIVE 128 /* A negative number, including "-0" */ +#define PNG_FP_NONZERO 256 /* A non-zero value */ +#define PNG_FP_STICKY 448 /* The above three flags */ + +/* This is available for the caller to store in 'state' if required. Do not + * call the parser after setting it (the parser sometimes clears it.) + */ +#define PNG_FP_INVALID 512 /* Available for callers as a distinct value */ + +/* Result codes for the parser (boolean - true meants ok, false means + * not ok yet.) + */ +#define PNG_FP_MAYBE 0 /* The number may be valid in the future */ +#define PNG_FP_OK 1 /* The number is valid */ + +/* Tests on the sticky non-zero and negative flags. To pass these checks + * the state must also indicate that the whole number is valid - this is + * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this + * is equivalent to PNG_FP_OK above.) + */ +#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO) + /* NZ_MASK: the string is valid and a non-zero negative value */ +#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO) + /* Z MASK: the string is valid and a non-zero value. */ + /* PNG_FP_SAW_DIGIT: the string is valid. */ +#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT) +#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK) +#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK) + +/* The actual parser. This can be called repeatedly. It updates + * the index into the string and the state variable (which must + * be initialized to 0). It returns a result code, as above. There + * is no point calling the parser any more if it fails to advance to + * the end of the string - it is stuck on an invalid character (or + * terminated by '\0'). + * + * Note that the pointer will consume an E or even an E+ and then leave + * a 'maybe' state even though a preceding integer.fraction is valid. + * The PNG_FP_WAS_VALID flag indicates that a preceding substring was + * a valid number. It's possible to recover from this by calling + * the parser again (from the start, with state 0) but with a string + * that omits the last character (i.e. set the size to the index of + * the problem character.) This has not been tested within libpng. + */ +PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string, + png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY); + +/* This is the same but it checks a complete string and returns true + * only if it just contains a floating point number. As of 1.5.4 this + * function also returns the state at the end of parsing the number if + * it was valid (otherwise it returns 0.) This can be used for testing + * for negative or zero values using the sticky flag. + */ +PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string, + png_size_t size),PNG_EMPTY); +#endif /* pCAL || sCAL */ + +#if defined(PNG_GAMMA_SUPPORTED) ||\ + defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) +/* Added at libpng version 1.5.0 */ +/* This is a utility to provide a*times/div (rounded) and indicate + * if there is an overflow. The result is a boolean - false (0) + * for overflow, true (1) if no overflow, in which case *res + * holds the result. + */ +PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a, + png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY); +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) +/* Same deal, but issue a warning on overflow and return 0. */ +PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn, + (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by, + png_int_32 divided_by),PNG_EMPTY); +#endif + +#ifdef PNG_GAMMA_SUPPORTED +/* Calculate a reciprocal - used for gamma values. This returns + * 0 if the argument is 0 in order to maintain an undefined value; + * there are no warnings. + */ +PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a), + PNG_EMPTY); + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* The same but gives a reciprocal of the product of two fixed point + * values. Accuracy is suitable for gamma calculations but this is + * not exact - use png_muldiv for that. Only required at present on read. + */ +PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a, + png_fixed_point b),PNG_EMPTY); +#endif + +/* Return true if the gamma value is significantly different from 1.0 */ +PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value), + PNG_EMPTY); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Internal fixed point gamma correction. These APIs are called as + * required to convert single values - they don't need to be fast, + * they are not used when processing image pixel values. + * + * While the input is an 'unsigned' value it must actually be the + * correct bit value - 0..255 or 0..65535 as required. + */ +PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr, + unsigned int value, png_fixed_point gamma_value),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value, + png_fixed_point gamma_value),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value, + png_fixed_point gamma_value),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr), + PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr, + int bit_depth),PNG_EMPTY); +#endif + +/* SIMPLIFIED READ/WRITE SUPPORT */ +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\ + defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) +/* The internal structure that png_image::opaque points to. */ +typedef struct png_control +{ + png_structp png_ptr; + png_infop info_ptr; + png_voidp error_buf; /* Always a jmp_buf at present. */ + + png_const_bytep memory; /* Memory buffer. */ + png_size_t size; /* Size of the memory buffer. */ + + unsigned int for_write :1; /* Otherwise it is a read structure */ + unsigned int owned_file :1; /* We own the file in io_ptr */ +} png_control; + +/* Return the pointer to the jmp_buf from a png_control: necessary because C + * does not reveal the type of the elements of jmp_buf. + */ +#ifdef __cplusplus +# define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0]) +#else +# define png_control_jmp_buf(pc) ((pc)->error_buf) +#endif + +/* Utility to safely execute a piece of libpng code catching and logging any + * errors that might occur. Returns true on success, false on failure (either + * of the function or as a result of a png_error.) + */ +PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr, + png_const_charp error_message),PNG_NORETURN); + +#ifdef PNG_WARNINGS_SUPPORTED +PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr, + png_const_charp warning_message),PNG_EMPTY); +#else +# define png_safe_warning 0/*dummy argument*/ +#endif + +PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image, + int (*function)(png_voidp), png_voidp arg),PNG_EMPTY); + +/* Utility to log an error; this also cleans up the png_image; the function + * always returns 0 (false). + */ +PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image, + png_const_charp error_message),PNG_EMPTY); + +#ifndef PNG_SIMPLIFIED_READ_SUPPORTED +/* png_image_free is used by the write code but not exported */ +PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY); +#endif /* !SIMPLIFIED_READ */ + +#endif /* SIMPLIFIED READ/WRITE */ + +/* These are initialization functions for hardware specific PNG filter + * optimizations; list these here then select the appropriate one at compile + * time using the macro PNG_FILTER_OPTIMIZATIONS. If the macro is not defined + * the generic code is used. + */ +#ifdef PNG_FILTER_OPTIMIZATIONS +PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr, + unsigned int bpp), PNG_EMPTY); + /* Just declare the optimization that will be used */ +#else + /* List *all* the possible optimizations here - this branch is required if + * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in + * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing. + */ +PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon, + (png_structp png_ptr, unsigned int bpp), PNG_EMPTY); +#endif + +PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr, + png_const_charp key, png_bytep new_key), PNG_EMPTY); + +/* Maintainer: Put new private prototypes here ^ */ + +#include "pngdebug.h" + +#ifdef __cplusplus +} +#endif + +#endif /* PNG_VERSION_INFO_ONLY */ +#endif /* PNGPRIV_H */ diff --git a/thirdparty/libpng/pngread.c b/thirdparty/libpng/pngread.c new file mode 100644 index 0000000000..0ff6238023 --- /dev/null +++ b/thirdparty/libpng/pngread.c @@ -0,0 +1,4172 @@ + +/* pngread.c - read a PNG file + * + * Last changed in libpng 1.6.23 [June 9, 2016] + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains routines that an application calls directly to + * read a PNG file or stream. + */ + +#include "pngpriv.h" +#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) +# include <errno.h> +#endif + +#ifdef PNG_READ_SUPPORTED + +/* Create a PNG structure for reading, and allocate any memory needed. */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) +{ +#ifndef PNG_USER_MEM_SUPPORTED + png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, NULL, NULL, NULL); +#else + return png_create_read_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, NULL, NULL, NULL); +} + +/* Alternate create PNG structure for reading, and allocate any memory + * needed. + */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ + png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); +#endif /* USER_MEM */ + + if (png_ptr != NULL) + { + png_ptr->mode = PNG_IS_READ_STRUCT; + + /* Added in libpng-1.6.0; this can be used to detect a read structure if + * required (it will be zero in a write structure.) + */ +# ifdef PNG_SEQUENTIAL_READ_SUPPORTED + png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE; +# endif + +# ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; + + /* In stable builds only warn if an application error can be completely + * handled. + */ +# if PNG_RELEASE_BUILD + png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; +# endif +# endif + + /* TODO: delay this, it can be done in png_init_io (if the app doesn't + * do it itself) avoiding setting the default function if it is not + * required. + */ + png_set_read_fn(png_ptr, NULL, NULL); + } + + return png_ptr; +} + + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the information before the actual image data. This has been + * changed in v0.90 to allow reading a file that already has the magic + * bytes read from the stream. You can tell libpng how many bytes have + * been read from the beginning of the stream (up to the maximum of 8) + * via png_set_sig_bytes(), and we will only check the remaining bytes + * here. The application can then have access to the signature bytes we + * read if it is determined that this isn't a valid PNG file. + */ +void PNGAPI +png_read_info(png_structrp png_ptr, png_inforp info_ptr) +{ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int keep; +#endif + + png_debug(1, "in png_read_info"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Read and check the PNG file signature. */ + png_read_sig(png_ptr, info_ptr); + + for (;;) + { + png_uint_32 length = png_read_chunk_header(png_ptr); + png_uint_32 chunk_name = png_ptr->chunk_name; + + /* IDAT logic needs to happen here to simplify getting the two flags + * right. + */ + if (chunk_name == png_IDAT) + { + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + (png_ptr->mode & PNG_HAVE_PLTE) == 0) + png_chunk_error(png_ptr, "Missing PLTE before IDAT"); + + else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0) + png_chunk_benign_error(png_ptr, "Too many IDATs found"); + + png_ptr->mode |= PNG_HAVE_IDAT; + } + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + png_ptr->mode |= PNG_AFTER_IDAT; + } + + /* This should be a binary subdivision search or a hash for + * matching the chunk name rather than a linear search. + */ + if (chunk_name == png_IHDR) + png_handle_IHDR(png_ptr, info_ptr, length); + + else if (chunk_name == png_IEND) + png_handle_IEND(png_ptr, info_ptr, length); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) + { + png_handle_unknown(png_ptr, info_ptr, length, keep); + + if (chunk_name == png_PLTE) + png_ptr->mode |= PNG_HAVE_PLTE; + + else if (chunk_name == png_IDAT) + { + png_ptr->idat_size = 0; /* It has been consumed */ + break; + } + } +#endif + else if (chunk_name == png_PLTE) + png_handle_PLTE(png_ptr, info_ptr, length); + + else if (chunk_name == png_IDAT) + { + png_ptr->idat_size = length; + break; + } + +#ifdef PNG_READ_bKGD_SUPPORTED + else if (chunk_name == png_bKGD) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED + else if (chunk_name == png_cHRM) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (chunk_name == png_gAMA) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + else if (chunk_name == png_hIST) + png_handle_hIST(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED + else if (chunk_name == png_oFFs) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (chunk_name == png_pCAL) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED + else if (chunk_name == png_sCAL) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED + else if (chunk_name == png_pHYs) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED + else if (chunk_name == png_sBIT) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED + else if (chunk_name == png_sRGB) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED + else if (chunk_name == png_iCCP) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED + else if (chunk_name == png_sPLT) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED + else if (chunk_name == png_tEXt) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED + else if (chunk_name == png_tIME) + png_handle_tIME(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED + else if (chunk_name == png_tRNS) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED + else if (chunk_name == png_zTXt) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED + else if (chunk_name == png_iTXt) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + + else + png_handle_unknown(png_ptr, info_ptr, length, + PNG_HANDLE_CHUNK_AS_DEFAULT); + } +} +#endif /* SEQUENTIAL_READ */ + +/* Optional call to update the users info_ptr structure */ +void PNGAPI +png_read_update_info(png_structrp png_ptr, png_inforp info_ptr) +{ + png_debug(1, "in png_read_update_info"); + + if (png_ptr != NULL) + { + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + { + png_read_start_row(png_ptr); + +# ifdef PNG_READ_TRANSFORMS_SUPPORTED + png_read_transform_info(png_ptr, info_ptr); +# else + PNG_UNUSED(info_ptr) +# endif + } + + /* New in 1.6.0 this avoids the bug of doing the initializations twice */ + else + png_app_error(png_ptr, + "png_read_update_info/png_start_read_image: duplicate call"); + } +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Initialize palette, background, etc, after transformations + * are set, but before any reading takes place. This allows + * the user to obtain a gamma-corrected palette, for example. + * If the user doesn't call this, we will do it ourselves. + */ +void PNGAPI +png_start_read_image(png_structrp png_ptr) +{ + png_debug(1, "in png_start_read_image"); + + if (png_ptr != NULL) + { + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + png_read_start_row(png_ptr); + + /* New in 1.6.0 this avoids the bug of doing the initializations twice */ + else + png_app_error(png_ptr, + "png_start_read_image/png_read_update_info: duplicate call"); + } +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +#ifdef PNG_MNG_FEATURES_SUPPORTED +/* Undoes intrapixel differencing, + * NOTE: this is apparently only supported in the 'sequential' reader. + */ +static void +png_do_read_intrapixel(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_read_intrapixel"); + + if ( + (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + int bytes_per_pixel; + png_uint_32 row_width = row_info->width; + + if (row_info->bit_depth == 8) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 3; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 4; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff); + *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff); + } + } + else if (row_info->bit_depth == 16) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 6; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 8; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); + png_uint_32 red = (s0 + s1 + 65536) & 0xffff; + png_uint_32 blue = (s2 + s1 + 65536) & 0xffff; + *(rp ) = (png_byte)((red >> 8) & 0xff); + *(rp + 1) = (png_byte)(red & 0xff); + *(rp + 4) = (png_byte)((blue >> 8) & 0xff); + *(rp + 5) = (png_byte)(blue & 0xff); + } + } + } +} +#endif /* MNG_FEATURES */ + +void PNGAPI +png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row) +{ + png_row_info row_info; + + if (png_ptr == NULL) + return; + + png_debug2(1, "in png_read_row (row %lu, pass %d)", + (unsigned long)png_ptr->row_number, png_ptr->pass); + + /* png_read_start_row sets the information (in particular iwidth) for this + * interlace pass. + */ + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + png_read_start_row(png_ptr); + + /* 1.5.6: row_info moved out of png_struct to a local here. */ + row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ + row_info.color_type = png_ptr->color_type; + row_info.bit_depth = png_ptr->bit_depth; + row_info.channels = png_ptr->channels; + row_info.pixel_depth = png_ptr->pixel_depth; + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + +#ifdef PNG_WARNINGS_SUPPORTED + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + /* Check for transforms that have been set but were defined out */ +#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED) + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ + !defined(PNG_READ_PACKSWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED) + if ((png_ptr->transformations & PNG_PACK) != 0) + png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED) + if ((png_ptr->transformations & PNG_BGR) != 0) + png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined"); +#endif + } +#endif /* WARNINGS */ + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* If interlaced and we do not need a new row, combine row and return. + * Notice that the pixels we have from previous rows have been transformed + * already; we can only combine like with like (transformed or + * untransformed) and, because of the libpng API for interlaced images, this + * means we must transform before de-interlacing. + */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + switch (png_ptr->pass) + { + case 0: + if (png_ptr->row_number & 0x07) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + png_read_finish_row(png_ptr); + return; + } + break; + + case 1: + if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 2: + if ((png_ptr->row_number & 0x07) != 4) + { + if (dsp_row != NULL && (png_ptr->row_number & 4)) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 3: + if ((png_ptr->row_number & 3) || png_ptr->width < 3) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 4: + if ((png_ptr->row_number & 3) != 2) + { + if (dsp_row != NULL && (png_ptr->row_number & 2)) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 5: + if ((png_ptr->row_number & 1) || png_ptr->width < 2) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + png_read_finish_row(png_ptr); + return; + } + break; + + default: + case 6: + if ((png_ptr->row_number & 1) == 0) + { + png_read_finish_row(png_ptr); + return; + } + break; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) + png_error(png_ptr, "Invalid attempt to read row data"); + + /* Fill the row with IDAT data: */ + png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1); + + if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) + { + if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) + png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, + png_ptr->prev_row + 1, png_ptr->row_buf[0]); + else + png_error(png_ptr, "bad adaptive filter value"); + } + + /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before + * 1.5.6, while the buffer really is this big in current versions of libpng + * it may not be in the future, so this was changed just to copy the + * interlaced count: + */ + memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) + { + /* Intrapixel differencing */ + png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1); + } +#endif + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + if (png_ptr->transformations) + png_do_read_transformations(png_ptr, &row_info); +#endif + + /* The transformed pixel depth should match the depth now in row_info. */ + if (png_ptr->transformed_pixel_depth == 0) + { + png_ptr->transformed_pixel_depth = row_info.pixel_depth; + if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) + png_error(png_ptr, "sequential row overflow"); + } + + else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) + png_error(png_ptr, "internal sequential row size calculation error"); + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Expand interlaced rows to full size */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + if (png_ptr->pass < 6) + png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, + png_ptr->transformations); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 1/*display*/); + + if (row != NULL) + png_combine_row(png_ptr, row, 0/*row*/); + } + + else +#endif + { + if (row != NULL) + png_combine_row(png_ptr, row, -1/*ignored*/); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, -1/*ignored*/); + } + png_read_finish_row(png_ptr); + + if (png_ptr->read_row_fn != NULL) + (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); + +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read one or more rows of image data. If the image is interlaced, + * and png_set_interlace_handling() has been called, the rows need to + * contain the contents of the rows from the previous pass. If the + * image has alpha or transparency, and png_handle_alpha()[*] has been + * called, the rows contents must be initialized to the contents of the + * screen. + * + * "row" holds the actual image, and pixels are placed in it + * as they arrive. If the image is displayed after each pass, it will + * appear to "sparkle" in. "display_row" can be used to display a + * "chunky" progressive image, with finer detail added as it becomes + * available. If you do not want this "chunky" display, you may pass + * NULL for display_row. If you do not want the sparkle display, and + * you have not called png_handle_alpha(), you may pass NULL for rows. + * If you have called png_handle_alpha(), and the image has either an + * alpha channel or a transparency chunk, you must provide a buffer for + * rows. In this case, you do not have to provide a display_row buffer + * also, but you may. If the image is not interlaced, or if you have + * not called png_set_interlace_handling(), the display_row buffer will + * be ignored, so pass NULL to it. + * + * [*] png_handle_alpha() does not exist yet, as of this version of libpng + */ + +void PNGAPI +png_read_rows(png_structrp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows) +{ + png_uint_32 i; + png_bytepp rp; + png_bytepp dp; + + png_debug(1, "in png_read_rows"); + + if (png_ptr == NULL) + return; + + rp = row; + dp = display_row; + if (rp != NULL && dp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep rptr = *rp++; + png_bytep dptr = *dp++; + + png_read_row(png_ptr, rptr, dptr); + } + + else if (rp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep rptr = *rp; + png_read_row(png_ptr, rptr, NULL); + rp++; + } + + else if (dp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep dptr = *dp; + png_read_row(png_ptr, NULL, dptr); + dp++; + } +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the entire image. If the image has an alpha channel or a tRNS + * chunk, and you have called png_handle_alpha()[*], you will need to + * initialize the image to the current image that PNG will be overlaying. + * We set the num_rows again here, in case it was incorrectly set in + * png_read_start_row() by a call to png_read_update_info() or + * png_start_read_image() if png_set_interlace_handling() wasn't called + * prior to either of these functions like it should have been. You can + * only call this function once. If you desire to have an image for + * each pass of a interlaced image, use png_read_rows() instead. + * + * [*] png_handle_alpha() does not exist yet, as of this version of libpng + */ +void PNGAPI +png_read_image(png_structrp png_ptr, png_bytepp image) +{ + png_uint_32 i, image_height; + int pass, j; + png_bytepp rp; + + png_debug(1, "in png_read_image"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + { + pass = png_set_interlace_handling(png_ptr); + /* And make sure transforms are initialized. */ + png_start_read_image(png_ptr); + } + else + { + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) == 0) + { + /* Caller called png_start_read_image or png_read_update_info without + * first turning on the PNG_INTERLACE transform. We can fix this here, + * but the caller should do it! + */ + png_warning(png_ptr, "Interlace handling should be turned on when " + "using png_read_image"); + /* Make sure this is set correctly */ + png_ptr->num_rows = png_ptr->height; + } + + /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in + * the above error case. + */ + pass = png_set_interlace_handling(png_ptr); + } +#else + if (png_ptr->interlaced) + png_error(png_ptr, + "Cannot read interlaced image -- interlace handler disabled"); + + pass = 1; +#endif + + image_height=png_ptr->height; + + for (j = 0; j < pass; j++) + { + rp = image; + for (i = 0; i < image_height; i++) + { + png_read_row(png_ptr, *rp, NULL); + rp++; + } + } +} +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the end of the PNG file. Will not read past the end of the + * file, will verify the end is accurate, and will read any comments + * or time information at the end of the file, if info is not NULL. + */ +void PNGAPI +png_read_end(png_structrp png_ptr, png_inforp info_ptr) +{ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int keep; +#endif + + png_debug(1, "in png_read_end"); + + if (png_ptr == NULL) + return; + + /* If png_read_end is called in the middle of reading the rows there may + * still be pending IDAT data and an owned zstream. Deal with this here. + */ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0) +#endif + png_read_finish_IDAT(png_ptr); + +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Report invalid palette index; added at libng-1.5.10 */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Read palette index exceeding num_palette"); +#endif + + do + { + png_uint_32 length = png_read_chunk_header(png_ptr); + png_uint_32 chunk_name = png_ptr->chunk_name; + + if (chunk_name != png_IDAT) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + if (chunk_name == png_IEND) + png_handle_IEND(png_ptr, info_ptr, length); + + else if (chunk_name == png_IHDR) + png_handle_IHDR(png_ptr, info_ptr, length); + + else if (info_ptr == NULL) + png_crc_finish(png_ptr, length); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) + { + if (chunk_name == png_IDAT) + { + if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) + || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) + png_benign_error(png_ptr, ".Too many IDATs found"); + } + png_handle_unknown(png_ptr, info_ptr, length, keep); + if (chunk_name == png_PLTE) + png_ptr->mode |= PNG_HAVE_PLTE; + } +#endif + + else if (chunk_name == png_IDAT) + { + /* Zero length IDATs are legal after the last IDAT has been + * read, but not after other chunks have been read. 1.6 does not + * always read all the deflate data; specifically it cannot be relied + * upon to read the Adler32 at the end. If it doesn't ignore IDAT + * chunks which are longer than zero as well: + */ + if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) + || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0) + png_benign_error(png_ptr, "..Too many IDATs found"); + + png_crc_finish(png_ptr, length); + } + else if (chunk_name == png_PLTE) + png_handle_PLTE(png_ptr, info_ptr, length); + +#ifdef PNG_READ_bKGD_SUPPORTED + else if (chunk_name == png_bKGD) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED + else if (chunk_name == png_cHRM) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (chunk_name == png_gAMA) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + else if (chunk_name == png_hIST) + png_handle_hIST(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED + else if (chunk_name == png_oFFs) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (chunk_name == png_pCAL) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED + else if (chunk_name == png_sCAL) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED + else if (chunk_name == png_pHYs) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED + else if (chunk_name == png_sBIT) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED + else if (chunk_name == png_sRGB) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED + else if (chunk_name == png_iCCP) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED + else if (chunk_name == png_sPLT) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED + else if (chunk_name == png_tEXt) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED + else if (chunk_name == png_tIME) + png_handle_tIME(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED + else if (chunk_name == png_tRNS) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED + else if (chunk_name == png_zTXt) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED + else if (chunk_name == png_iTXt) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + + else + png_handle_unknown(png_ptr, info_ptr, length, + PNG_HANDLE_CHUNK_AS_DEFAULT); + } while ((png_ptr->mode & PNG_HAVE_IEND) == 0); +} +#endif /* SEQUENTIAL_READ */ + +/* Free all memory used in the read struct */ +static void +png_read_destroy(png_structrp png_ptr) +{ + png_debug(1, "in png_read_destroy"); + +#ifdef PNG_READ_GAMMA_SUPPORTED + png_destroy_gamma_table(png_ptr); +#endif + + png_free(png_ptr, png_ptr->big_row_buf); + png_ptr->big_row_buf = NULL; + png_free(png_ptr, png_ptr->big_prev_row); + png_ptr->big_prev_row = NULL; + png_free(png_ptr, png_ptr->read_buffer); + png_ptr->read_buffer = NULL; + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + png_free(png_ptr, png_ptr->palette_lookup); + png_ptr->palette_lookup = NULL; + png_free(png_ptr, png_ptr->quantize_index); + png_ptr->quantize_index = NULL; +#endif + + if ((png_ptr->free_me & PNG_FREE_PLTE) != 0) + { + png_zfree(png_ptr, png_ptr->palette); + png_ptr->palette = NULL; + } + png_ptr->free_me &= ~PNG_FREE_PLTE; + +#if defined(PNG_tRNS_SUPPORTED) || \ + defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + if ((png_ptr->free_me & PNG_FREE_TRNS) != 0) + { + png_free(png_ptr, png_ptr->trans_alpha); + png_ptr->trans_alpha = NULL; + } + png_ptr->free_me &= ~PNG_FREE_TRNS; +#endif + + inflateEnd(&png_ptr->zstream); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_free(png_ptr, png_ptr->save_buffer); + png_ptr->save_buffer = NULL; +#endif + +#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \ + defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->chunk_list = NULL; +#endif + + /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error + * callbacks are still set at this point. They are required to complete the + * destruction of the png_struct itself. + */ +} + +/* Free all memory used by the read */ +void PNGAPI +png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, + png_infopp end_info_ptr_ptr) +{ + png_structrp png_ptr = NULL; + + png_debug(1, "in png_destroy_read_struct"); + + if (png_ptr_ptr != NULL) + png_ptr = *png_ptr_ptr; + + if (png_ptr == NULL) + return; + + /* libpng 1.6.0: use the API to destroy info structs to ensure consistent + * behavior. Prior to 1.6.0 libpng did extra 'info' destruction in this API. + * The extra was, apparently, unnecessary yet this hides memory leak bugs. + */ + png_destroy_info_struct(png_ptr, end_info_ptr_ptr); + png_destroy_info_struct(png_ptr, info_ptr_ptr); + + *png_ptr_ptr = NULL; + png_read_destroy(png_ptr); + png_destroy_png_struct(png_ptr); +} + +void PNGAPI +png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->read_row_fn = read_row_fn; +} + + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_read_png(png_structrp png_ptr, png_inforp info_ptr, + int transforms, + voidp params) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* png_read_info() gives us all of the information from the + * PNG file before the first IDAT (image data chunk). + */ + png_read_info(png_ptr, info_ptr); + if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep))) + png_error(png_ptr, "Image is too high to process with png_read_png()"); + + /* -------------- image transformations start here ------------------- */ + /* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM + * is not implemented. This will only happen in de-configured (non-default) + * libpng builds. The results can be unexpected - png_read_png may return + * short or mal-formed rows because the transform is skipped. + */ + + /* Tell libpng to strip 16-bit/color files down to 8 bits per color. + */ + if ((transforms & PNG_TRANSFORM_SCALE_16) != 0) + /* Added at libpng-1.5.4. "strip_16" produces the same result that it + * did in earlier versions, while "scale_16" is now more accurate. + */ +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + png_set_scale_16(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported"); +#endif + + /* If both SCALE and STRIP are required pngrtran will effectively cancel the + * latter by doing SCALE first. This is ok and allows apps not to check for + * which is supported to get the right answer. + */ + if ((transforms & PNG_TRANSFORM_STRIP_16) != 0) +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + png_set_strip_16(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported"); +#endif + + /* Strip alpha bytes from the input data without combining with + * the background (not recommended). + */ + if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0) +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + png_set_strip_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported"); +#endif + + /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single + * byte into separate bytes (useful for paletted and grayscale images). + */ + if ((transforms & PNG_TRANSFORM_PACKING) != 0) +#ifdef PNG_READ_PACK_SUPPORTED + png_set_packing(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); +#endif + + /* Change the order of packed pixels to least significant bit first + * (not useful if you are using png_set_packing). + */ + if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) +#ifdef PNG_READ_PACKSWAP_SUPPORTED + png_set_packswap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); +#endif + + /* Expand paletted colors into true RGB triplets + * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel + * Expand paletted or RGB images with transparency to full alpha + * channels so the data will be available as RGBA quartets. + */ + if ((transforms & PNG_TRANSFORM_EXPAND) != 0) +#ifdef PNG_READ_EXPAND_SUPPORTED + png_set_expand(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported"); +#endif + + /* We don't handle background color or gamma transformation or quantizing. + */ + + /* Invert monochrome files to have 0 as white and 1 as black + */ + if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) +#ifdef PNG_READ_INVERT_SUPPORTED + png_set_invert_mono(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); +#endif + + /* If you want to shift the pixel values from the range [0,255] or + * [0,65535] to the original [0,7] or [0,31], or whatever range the + * colors were originally in: + */ + if ((transforms & PNG_TRANSFORM_SHIFT) != 0) +#ifdef PNG_READ_SHIFT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_set_shift(png_ptr, &info_ptr->sig_bit); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); +#endif + + /* Flip the RGB pixels to BGR (or RGBA to BGRA) */ + if ((transforms & PNG_TRANSFORM_BGR) != 0) +#ifdef PNG_READ_BGR_SUPPORTED + png_set_bgr(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); +#endif + + /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ + if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + png_set_swap_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); +#endif + + /* Swap bytes of 16-bit files to least significant byte first */ + if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) +#ifdef PNG_READ_SWAP_SUPPORTED + png_set_swap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); +#endif + +/* Added at libpng-1.2.41 */ + /* Invert the alpha channel from opacity to transparency */ + if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + png_set_invert_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); +#endif + +/* Added at libpng-1.2.41 */ + /* Expand grayscale image to RGB */ + if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0) +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + png_set_gray_to_rgb(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported"); +#endif + +/* Added at libpng-1.5.4 */ + if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0) +#ifdef PNG_READ_EXPAND_16_SUPPORTED + png_set_expand_16(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported"); +#endif + + /* We don't handle adding filler bytes */ + + /* We use png_read_image and rely on that for interlace handling, but we also + * call png_read_update_info therefore must turn on interlace handling now: + */ + (void)png_set_interlace_handling(png_ptr); + + /* Optional call to gamma correct and add the background to the palette + * and update info structure. REQUIRED if you are expecting libpng to + * update the palette for you (i.e., you selected such a transform above). + */ + png_read_update_info(png_ptr, info_ptr); + + /* -------------- image transformations end here ------------------- */ + + png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); + if (info_ptr->row_pointers == NULL) + { + png_uint_32 iptr; + + info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr, + info_ptr->height * (sizeof (png_bytep)))); + + for (iptr=0; iptr<info_ptr->height; iptr++) + info_ptr->row_pointers[iptr] = NULL; + + info_ptr->free_me |= PNG_FREE_ROWS; + + for (iptr = 0; iptr < info_ptr->height; iptr++) + info_ptr->row_pointers[iptr] = png_voidcast(png_bytep, + png_malloc(png_ptr, info_ptr->rowbytes)); + } + + png_read_image(png_ptr, info_ptr->row_pointers); + info_ptr->valid |= PNG_INFO_IDAT; + + /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ + png_read_end(png_ptr, info_ptr); + + PNG_UNUSED(params) +} +#endif /* INFO_IMAGE */ +#endif /* SEQUENTIAL_READ */ + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED +/* SIMPLIFIED READ + * + * This code currently relies on the sequential reader, though it could easily + * be made to work with the progressive one. + */ +/* Arguments to png_image_finish_read: */ + +/* Encoding of PNG data (used by the color-map code) */ +# define P_NOTSET 0 /* File encoding not yet known */ +# define P_sRGB 1 /* 8-bit encoded to sRGB gamma */ +# define P_LINEAR 2 /* 16-bit linear: not encoded, NOT pre-multiplied! */ +# define P_FILE 3 /* 8-bit encoded to file gamma, not sRGB or linear */ +# define P_LINEAR8 4 /* 8-bit linear: only from a file value */ + +/* Color-map processing: after libpng has run on the PNG image further + * processing may be needed to convert the data to color-map indices. + */ +#define PNG_CMAP_NONE 0 +#define PNG_CMAP_GA 1 /* Process GA data to a color-map with alpha */ +#define PNG_CMAP_TRANS 2 /* Process GA data to a background index */ +#define PNG_CMAP_RGB 3 /* Process RGB data */ +#define PNG_CMAP_RGB_ALPHA 4 /* Process RGBA data */ + +/* The following document where the background is for each processing case. */ +#define PNG_CMAP_NONE_BACKGROUND 256 +#define PNG_CMAP_GA_BACKGROUND 231 +#define PNG_CMAP_TRANS_BACKGROUND 254 +#define PNG_CMAP_RGB_BACKGROUND 256 +#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216 + +typedef struct +{ + /* Arguments: */ + png_imagep image; + png_voidp buffer; + png_int_32 row_stride; + png_voidp colormap; + png_const_colorp background; + /* Local variables: */ + png_voidp local_row; + png_voidp first_row; + ptrdiff_t row_bytes; /* step between rows */ + int file_encoding; /* E_ values above */ + png_fixed_point gamma_to_linear; /* For P_FILE, reciprocal of gamma */ + int colormap_processing; /* PNG_CMAP_ values above */ +} png_image_read_control; + +/* Do all the *safe* initialization - 'safe' means that png_error won't be + * called, so setting up the jmp_buf is not required. This means that anything + * called from here must *not* call png_malloc - it has to call png_malloc_warn + * instead so that control is returned safely back to this routine. + */ +static int +png_image_read_init(png_imagep image) +{ + if (image->opaque == NULL) + { + png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image, + png_safe_error, png_safe_warning); + + /* And set the rest of the structure to NULL to ensure that the various + * fields are consistent. + */ + memset(image, 0, (sizeof *image)); + image->version = PNG_IMAGE_VERSION; + + if (png_ptr != NULL) + { + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (info_ptr != NULL) + { + png_controlp control = png_voidcast(png_controlp, + png_malloc_warn(png_ptr, (sizeof *control))); + + if (control != NULL) + { + memset(control, 0, (sizeof *control)); + + control->png_ptr = png_ptr; + control->info_ptr = info_ptr; + control->for_write = 0; + + image->opaque = control; + return 1; + } + + /* Error clean up */ + png_destroy_info_struct(png_ptr, &info_ptr); + } + + png_destroy_read_struct(&png_ptr, NULL, NULL); + } + + return png_image_error(image, "png_image_read: out of memory"); + } + + return png_image_error(image, "png_image_read: opaque pointer not NULL"); +} + +/* Utility to find the base format of a PNG file from a png_struct. */ +static png_uint_32 +png_image_format(png_structrp png_ptr) +{ + png_uint_32 format = 0; + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + format |= PNG_FORMAT_FLAG_COLOR; + + if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + format |= PNG_FORMAT_FLAG_ALPHA; + + /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS + * sets the png_struct fields; that's all we are interested in here. The + * precise interaction with an app call to png_set_tRNS and PNG file reading + * is unclear. + */ + else if (png_ptr->num_trans > 0) + format |= PNG_FORMAT_FLAG_ALPHA; + + if (png_ptr->bit_depth == 16) + format |= PNG_FORMAT_FLAG_LINEAR; + + if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0) + format |= PNG_FORMAT_FLAG_COLORMAP; + + return format; +} + +/* Is the given gamma significantly different from sRGB? The test is the same + * one used in pngrtran.c when deciding whether to do gamma correction. The + * arithmetic optimizes the division by using the fact that the inverse of the + * file sRGB gamma is 2.2 + */ +static int +png_gamma_not_sRGB(png_fixed_point g) +{ + if (g < PNG_FP_1) + { + /* An uninitialized gamma is assumed to be sRGB for the simplified API. */ + if (g == 0) + return 0; + + return png_gamma_significant((g * 11 + 2)/5 /* i.e. *2.2, rounded */); + } + + return 1; +} + +/* Do the main body of a 'png_image_begin_read' function; read the PNG file + * header and fill in all the information. This is executed in a safe context, + * unlike the init routine above. + */ +static int +png_image_read_header(png_voidp argument) +{ + png_imagep image = png_voidcast(png_imagep, argument); + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + + png_set_benign_errors(png_ptr, 1/*warn*/); + png_read_info(png_ptr, info_ptr); + + /* Do this the fast way; just read directly out of png_struct. */ + image->width = png_ptr->width; + image->height = png_ptr->height; + + { + png_uint_32 format = png_image_format(png_ptr); + + image->format = format; + +#ifdef PNG_COLORSPACE_SUPPORTED + /* Does the colorspace match sRGB? If there is no color endpoint + * (colorant) information assume yes, otherwise require the + * 'ENDPOINTS_MATCHP_sRGB' colorspace flag to have been set. If the + * colorspace has been determined to be invalid ignore it. + */ + if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags + & (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB| + PNG_COLORSPACE_INVALID)) == PNG_COLORSPACE_HAVE_ENDPOINTS)) + image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB; +#endif + } + + /* We need the maximum number of entries regardless of the format the + * application sets here. + */ + { + png_uint_32 cmap_entries; + + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_GRAY: + cmap_entries = 1U << png_ptr->bit_depth; + break; + + case PNG_COLOR_TYPE_PALETTE: + cmap_entries = png_ptr->num_palette; + break; + + default: + cmap_entries = 256; + break; + } + + if (cmap_entries > 256) + cmap_entries = 256; + + image->colormap_entries = cmap_entries; + } + + return 1; +} + +#ifdef PNG_STDIO_SUPPORTED +int PNGAPI +png_image_begin_read_from_stdio(png_imagep image, FILE* file) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file != NULL) + { + if (png_image_read_init(image) != 0) + { + /* This is slightly evil, but png_init_io doesn't do anything other + * than this and we haven't changed the standard IO functions so + * this saves a 'safe' function. + */ + image->opaque->png_ptr->io_ptr = file; + return png_safe_execute(image, png_image_read_header, image); + } + } + + else + return png_image_error(image, + "png_image_begin_read_from_stdio: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION"); + + return 0; +} + +int PNGAPI +png_image_begin_read_from_file(png_imagep image, const char *file_name) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file_name != NULL) + { + FILE *fp = fopen(file_name, "rb"); + + if (fp != NULL) + { + if (png_image_read_init(image) != 0) + { + image->opaque->png_ptr->io_ptr = fp; + image->opaque->owned_file = 1; + return png_safe_execute(image, png_image_read_header, image); + } + + /* Clean up: just the opened file. */ + (void)fclose(fp); + } + + else + return png_image_error(image, strerror(errno)); + } + + else + return png_image_error(image, + "png_image_begin_read_from_file: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION"); + + return 0; +} +#endif /* STDIO */ + +static void PNGCBAPI +png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need) +{ + if (png_ptr != NULL) + { + png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr); + if (image != NULL) + { + png_controlp cp = image->opaque; + if (cp != NULL) + { + png_const_bytep memory = cp->memory; + png_size_t size = cp->size; + + if (memory != NULL && size >= need) + { + memcpy(out, memory, need); + cp->memory = memory + need; + cp->size = size - need; + return; + } + + png_error(png_ptr, "read beyond end of data"); + } + } + + png_error(png_ptr, "invalid memory read"); + } +} + +int PNGAPI png_image_begin_read_from_memory(png_imagep image, + png_const_voidp memory, png_size_t size) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (memory != NULL && size > 0) + { + if (png_image_read_init(image) != 0) + { + /* Now set the IO functions to read from the memory buffer and + * store it into io_ptr. Again do this in-place to avoid calling a + * libpng function that requires error handling. + */ + image->opaque->memory = png_voidcast(png_const_bytep, memory); + image->opaque->size = size; + image->opaque->png_ptr->io_ptr = image; + image->opaque->png_ptr->read_data_fn = png_image_memory_read; + + return png_safe_execute(image, png_image_read_header, image); + } + } + + else + return png_image_error(image, + "png_image_begin_read_from_memory: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION"); + + return 0; +} + +/* Utility function to skip chunks that are not used by the simplified image + * read functions and an appropriate macro to call it. + */ +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +static void +png_image_skip_unused_chunks(png_structrp png_ptr) +{ + /* Prepare the reader to ignore all recognized chunks whose data will not + * be used, i.e., all chunks recognized by libpng except for those + * involved in basic image reading: + * + * IHDR, PLTE, IDAT, IEND + * + * Or image data handling: + * + * tRNS, bKGD, gAMA, cHRM, sRGB, [iCCP] and sBIT. + * + * This provides a small performance improvement and eliminates any + * potential vulnerability to security problems in the unused chunks. + * + * At present the iCCP chunk data isn't used, so iCCP chunk can be ignored + * too. This allows the simplified API to be compiled without iCCP support, + * however if the support is there the chunk is still checked to detect + * errors (which are unfortunately quite common.) + */ + { + static PNG_CONST png_byte chunks_to_process[] = { + 98, 75, 71, 68, '\0', /* bKGD */ + 99, 72, 82, 77, '\0', /* cHRM */ + 103, 65, 77, 65, '\0', /* gAMA */ +# ifdef PNG_READ_iCCP_SUPPORTED + 105, 67, 67, 80, '\0', /* iCCP */ +# endif + 115, 66, 73, 84, '\0', /* sBIT */ + 115, 82, 71, 66, '\0', /* sRGB */ + }; + + /* Ignore unknown chunks and all other chunks except for the + * IHDR, PLTE, tRNS, IDAT, and IEND chunks. + */ + png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER, + NULL, -1); + + /* But do not ignore image data handling chunks */ + png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT, + chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5); + } +} + +# define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p) +#else +# define PNG_SKIP_CHUNKS(p) ((void)0) +#endif /* HANDLE_AS_UNKNOWN */ + +/* The following macro gives the exact rounded answer for all values in the + * range 0..255 (it actually divides by 51.2, but the rounding still generates + * the correct numbers 0..5 + */ +#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8) + +/* Utility functions to make particular color-maps */ +static void +set_file_encoding(png_image_read_control *display) +{ + png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma; + if (png_gamma_significant(g) != 0) + { + if (png_gamma_not_sRGB(g) != 0) + { + display->file_encoding = P_FILE; + display->gamma_to_linear = png_reciprocal(g); + } + + else + display->file_encoding = P_sRGB; + } + + else + display->file_encoding = P_LINEAR8; +} + +static unsigned int +decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding) +{ + if (encoding == P_FILE) /* double check */ + encoding = display->file_encoding; + + if (encoding == P_NOTSET) /* must be the file encoding */ + { + set_file_encoding(display); + encoding = display->file_encoding; + } + + switch (encoding) + { + case P_FILE: + value = png_gamma_16bit_correct(value*257, display->gamma_to_linear); + break; + + case P_sRGB: + value = png_sRGB_table[value]; + break; + + case P_LINEAR: + break; + + case P_LINEAR8: + value *= 257; + break; + +#ifdef __GNUC__ + default: + png_error(display->image->opaque->png_ptr, + "unexpected encoding (internal error)"); +#endif + } + + return value; +} + +static png_uint_32 +png_colormap_compose(png_image_read_control *display, + png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha, + png_uint_32 background, int encoding) +{ + /* The file value is composed on the background, the background has the given + * encoding and so does the result, the file is encoded with P_FILE and the + * file and alpha are 8-bit values. The (output) encoding will always be + * P_LINEAR or P_sRGB. + */ + png_uint_32 f = decode_gamma(display, foreground, foreground_encoding); + png_uint_32 b = decode_gamma(display, background, encoding); + + /* The alpha is always an 8-bit value (it comes from the palette), the value + * scaled by 255 is what PNG_sRGB_FROM_LINEAR requires. + */ + f = f * alpha + b * (255-alpha); + + if (encoding == P_LINEAR) + { + /* Scale to 65535; divide by 255, approximately (in fact this is extremely + * accurate, it divides by 255.00000005937181414556, with no overflow.) + */ + f *= 257; /* Now scaled by 65535 */ + f += f >> 16; + f = (f+32768) >> 16; + } + + else /* P_sRGB */ + f = PNG_sRGB_FROM_LINEAR(f); + + return f; +} + +/* NOTE: P_LINEAR values to this routine must be 16-bit, but P_FILE values must + * be 8-bit. + */ +static void +png_create_colormap_entry(png_image_read_control *display, + png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue, + png_uint_32 alpha, int encoding) +{ + png_imagep image = display->image; + const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ? + P_LINEAR : P_sRGB; + const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 && + (red != green || green != blue); + + if (ip > 255) + png_error(image->opaque->png_ptr, "color-map index out of range"); + + /* Update the cache with whether the file gamma is significantly different + * from sRGB. + */ + if (encoding == P_FILE) + { + if (display->file_encoding == P_NOTSET) + set_file_encoding(display); + + /* Note that the cached value may be P_FILE too, but if it is then the + * gamma_to_linear member has been set. + */ + encoding = display->file_encoding; + } + + if (encoding == P_FILE) + { + png_fixed_point g = display->gamma_to_linear; + + red = png_gamma_16bit_correct(red*257, g); + green = png_gamma_16bit_correct(green*257, g); + blue = png_gamma_16bit_correct(blue*257, g); + + if (convert_to_Y != 0 || output_encoding == P_LINEAR) + { + alpha *= 257; + encoding = P_LINEAR; + } + + else + { + red = PNG_sRGB_FROM_LINEAR(red * 255); + green = PNG_sRGB_FROM_LINEAR(green * 255); + blue = PNG_sRGB_FROM_LINEAR(blue * 255); + encoding = P_sRGB; + } + } + + else if (encoding == P_LINEAR8) + { + /* This encoding occurs quite frequently in test cases because PngSuite + * includes a gAMA 1.0 chunk with most images. + */ + red *= 257; + green *= 257; + blue *= 257; + alpha *= 257; + encoding = P_LINEAR; + } + + else if (encoding == P_sRGB && + (convert_to_Y != 0 || output_encoding == P_LINEAR)) + { + /* The values are 8-bit sRGB values, but must be converted to 16-bit + * linear. + */ + red = png_sRGB_table[red]; + green = png_sRGB_table[green]; + blue = png_sRGB_table[blue]; + alpha *= 257; + encoding = P_LINEAR; + } + + /* This is set if the color isn't gray but the output is. */ + if (encoding == P_LINEAR) + { + if (convert_to_Y != 0) + { + /* NOTE: these values are copied from png_do_rgb_to_gray */ + png_uint_32 y = (png_uint_32)6968 * red + (png_uint_32)23434 * green + + (png_uint_32)2366 * blue; + + if (output_encoding == P_LINEAR) + y = (y + 16384) >> 15; + + else + { + /* y is scaled by 32768, we need it scaled by 255: */ + y = (y + 128) >> 8; + y *= 255; + y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7); + alpha = PNG_DIV257(alpha); + encoding = P_sRGB; + } + + blue = red = green = y; + } + + else if (output_encoding == P_sRGB) + { + red = PNG_sRGB_FROM_LINEAR(red * 255); + green = PNG_sRGB_FROM_LINEAR(green * 255); + blue = PNG_sRGB_FROM_LINEAR(blue * 255); + alpha = PNG_DIV257(alpha); + encoding = P_sRGB; + } + } + + if (encoding != output_encoding) + png_error(image->opaque->png_ptr, "bad encoding (internal error)"); + + /* Store the value. */ + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 && + (image->format & PNG_FORMAT_FLAG_ALPHA) != 0; +# else +# define afirst 0 +# endif +# ifdef PNG_FORMAT_BGR_SUPPORTED + const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; +# else +# define bgr 0 +# endif + + if (output_encoding == P_LINEAR) + { + png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap); + + entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format); + + /* The linear 16-bit values must be pre-multiplied by the alpha channel + * value, if less than 65535 (this is, effectively, composite on black + * if the alpha channel is removed.) + */ + switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format)) + { + case 4: + entry[afirst ? 0 : 3] = (png_uint_16)alpha; + /* FALL THROUGH */ + + case 3: + if (alpha < 65535) + { + if (alpha > 0) + { + blue = (blue * alpha + 32767U)/65535U; + green = (green * alpha + 32767U)/65535U; + red = (red * alpha + 32767U)/65535U; + } + + else + red = green = blue = 0; + } + entry[afirst + (2 ^ bgr)] = (png_uint_16)blue; + entry[afirst + 1] = (png_uint_16)green; + entry[afirst + bgr] = (png_uint_16)red; + break; + + case 2: + entry[1 ^ afirst] = (png_uint_16)alpha; + /* FALL THROUGH */ + + case 1: + if (alpha < 65535) + { + if (alpha > 0) + green = (green * alpha + 32767U)/65535U; + + else + green = 0; + } + entry[afirst] = (png_uint_16)green; + break; + + default: + break; + } + } + + else /* output encoding is P_sRGB */ + { + png_bytep entry = png_voidcast(png_bytep, display->colormap); + + entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format); + + switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format)) + { + case 4: + entry[afirst ? 0 : 3] = (png_byte)alpha; + case 3: + entry[afirst + (2 ^ bgr)] = (png_byte)blue; + entry[afirst + 1] = (png_byte)green; + entry[afirst + bgr] = (png_byte)red; + break; + + case 2: + entry[1 ^ afirst] = (png_byte)alpha; + case 1: + entry[afirst] = (png_byte)green; + break; + + default: + break; + } + } + +# ifdef afirst +# undef afirst +# endif +# ifdef bgr +# undef bgr +# endif + } +} + +static int +make_gray_file_colormap(png_image_read_control *display) +{ + unsigned int i; + + for (i=0; i<256; ++i) + png_create_colormap_entry(display, i, i, i, i, 255, P_FILE); + + return i; +} + +static int +make_gray_colormap(png_image_read_control *display) +{ + unsigned int i; + + for (i=0; i<256; ++i) + png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB); + + return i; +} +#define PNG_GRAY_COLORMAP_ENTRIES 256 + +static int +make_ga_colormap(png_image_read_control *display) +{ + unsigned int i, a; + + /* Alpha is retained, the output will be a color-map with entries + * selected by six levels of alpha. One transparent entry, 6 gray + * levels for all the intermediate alpha values, leaving 230 entries + * for the opaque grays. The color-map entries are the six values + * [0..5]*51, the GA processing uses PNG_DIV51(value) to find the + * relevant entry. + * + * if (alpha > 229) // opaque + * { + * // The 231 entries are selected to make the math below work: + * base = 0; + * entry = (231 * gray + 128) >> 8; + * } + * else if (alpha < 26) // transparent + * { + * base = 231; + * entry = 0; + * } + * else // partially opaque + * { + * base = 226 + 6 * PNG_DIV51(alpha); + * entry = PNG_DIV51(gray); + * } + */ + i = 0; + while (i < 231) + { + unsigned int gray = (i * 256 + 115) / 231; + png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB); + } + + /* 255 is used here for the component values for consistency with the code + * that undoes premultiplication in pngwrite.c. + */ + png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB); + + for (a=1; a<5; ++a) + { + unsigned int g; + + for (g=0; g<6; ++g) + png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51, + P_sRGB); + } + + return i; +} + +#define PNG_GA_COLORMAP_ENTRIES 256 + +static int +make_rgb_colormap(png_image_read_control *display) +{ + unsigned int i, r; + + /* Build a 6x6x6 opaque RGB cube */ + for (i=r=0; r<6; ++r) + { + unsigned int g; + + for (g=0; g<6; ++g) + { + unsigned int b; + + for (b=0; b<6; ++b) + png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255, + P_sRGB); + } + } + + return i; +} + +#define PNG_RGB_COLORMAP_ENTRIES 216 + +/* Return a palette index to the above palette given three 8-bit sRGB values. */ +#define PNG_RGB_INDEX(r,g,b) \ + ((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b))) + +static int +png_image_read_colormap(png_voidp argument) +{ + png_image_read_control *display = + png_voidcast(png_image_read_control*, argument); + const png_imagep image = display->image; + + const png_structrp png_ptr = image->opaque->png_ptr; + const png_uint_32 output_format = image->format; + const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ? + P_LINEAR : P_sRGB; + + unsigned int cmap_entries; + unsigned int output_processing; /* Output processing option */ + unsigned int data_encoding = P_NOTSET; /* Encoding libpng must produce */ + + /* Background information; the background color and the index of this color + * in the color-map if it exists (else 256). + */ + unsigned int background_index = 256; + png_uint_32 back_r, back_g, back_b; + + /* Flags to accumulate things that need to be done to the input. */ + int expand_tRNS = 0; + + /* Exclude the NYI feature of compositing onto a color-mapped buffer; it is + * very difficult to do, the results look awful, and it is difficult to see + * what possible use it is because the application can't control the + * color-map. + */ + if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 || + png_ptr->num_trans > 0) /* alpha in input */ && + ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */) + { + if (output_encoding == P_LINEAR) /* compose on black */ + back_b = back_g = back_r = 0; + + else if (display->background == NULL /* no way to remove it */) + png_error(png_ptr, + "a background color must be supplied to remove alpha/transparency"); + + /* Get a copy of the background color (this avoids repeating the checks + * below.) The encoding is 8-bit sRGB or 16-bit linear, depending on the + * output format. + */ + else + { + back_g = display->background->green; + if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0) + { + back_r = display->background->red; + back_b = display->background->blue; + } + else + back_b = back_r = back_g; + } + } + + else if (output_encoding == P_LINEAR) + back_b = back_r = back_g = 65535; + + else + back_b = back_r = back_g = 255; + + /* Default the input file gamma if required - this is necessary because + * libpng assumes that if no gamma information is present the data is in the + * output format, but the simplified API deduces the gamma from the input + * format. + */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) == 0) + { + /* Do this directly, not using the png_colorspace functions, to ensure + * that it happens even if the colorspace is invalid (though probably if + * it is the setting will be ignored) Note that the same thing can be + * achieved at the application interface with png_set_gAMA. + */ + if (png_ptr->bit_depth == 16 && + (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0) + png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR; + + else + png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE; + + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + } + + /* Decide what to do based on the PNG color type of the input data. The + * utility function png_create_colormap_entry deals with most aspects of the + * output transformations; this code works out how to produce bytes of + * color-map entries from the original format. + */ + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_GRAY: + if (png_ptr->bit_depth <= 8) + { + /* There at most 256 colors in the output, regardless of + * transparency. + */ + unsigned int step, i, val, trans = 256/*ignore*/, back_alpha = 0; + + cmap_entries = 1U << png_ptr->bit_depth; + if (cmap_entries > image->colormap_entries) + png_error(png_ptr, "gray[8] color-map: too few entries"); + + step = 255 / (cmap_entries - 1); + output_processing = PNG_CMAP_NONE; + + /* If there is a tRNS chunk then this either selects a transparent + * value or, if the output has no alpha, the background color. + */ + if (png_ptr->num_trans > 0) + { + trans = png_ptr->trans_color.gray; + + if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) + back_alpha = output_encoding == P_LINEAR ? 65535 : 255; + } + + /* png_create_colormap_entry just takes an RGBA and writes the + * corresponding color-map entry using the format from 'image', + * including the required conversion to sRGB or linear as + * appropriate. The input values are always either sRGB (if the + * gamma correction flag is 0) or 0..255 scaled file encoded values + * (if the function must gamma correct them). + */ + for (i=val=0; i<cmap_entries; ++i, val += step) + { + /* 'i' is a file value. While this will result in duplicated + * entries for 8-bit non-sRGB encoded files it is necessary to + * have non-gamma corrected values to do tRNS handling. + */ + if (i != trans) + png_create_colormap_entry(display, i, val, val, val, 255, + P_FILE/*8-bit with file gamma*/); + + /* Else this entry is transparent. The colors don't matter if + * there is an alpha channel (back_alpha == 0), but it does no + * harm to pass them in; the values are not set above so this + * passes in white. + * + * NOTE: this preserves the full precision of the application + * supplied background color when it is used. + */ + else + png_create_colormap_entry(display, i, back_r, back_g, back_b, + back_alpha, output_encoding); + } + + /* We need libpng to preserve the original encoding. */ + data_encoding = P_FILE; + + /* The rows from libpng, while technically gray values, are now also + * color-map indices; however, they may need to be expanded to 1 + * byte per pixel. This is what png_set_packing does (i.e., it + * unpacks the bit values into bytes.) + */ + if (png_ptr->bit_depth < 8) + png_set_packing(png_ptr); + } + + else /* bit depth is 16 */ + { + /* The 16-bit input values can be converted directly to 8-bit gamma + * encoded values; however, if a tRNS chunk is present 257 color-map + * entries are required. This means that the extra entry requires + * special processing; add an alpha channel, sacrifice gray level + * 254 and convert transparent (alpha==0) entries to that. + * + * Use libpng to chop the data to 8 bits. Convert it to sRGB at the + * same time to minimize quality loss. If a tRNS chunk is present + * this means libpng must handle it too; otherwise it is impossible + * to do the exact match on the 16-bit value. + * + * If the output has no alpha channel *and* the background color is + * gray then it is possible to let libpng handle the substitution by + * ensuring that the corresponding gray level matches the background + * color exactly. + */ + data_encoding = P_sRGB; + + if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "gray[16] color-map: too few entries"); + + cmap_entries = make_gray_colormap(display); + + if (png_ptr->num_trans > 0) + { + unsigned int back_alpha; + + if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + back_alpha = 0; + + else + { + if (back_r == back_g && back_g == back_b) + { + /* Background is gray; no special processing will be + * required. + */ + png_color_16 c; + png_uint_32 gray = back_g; + + if (output_encoding == P_LINEAR) + { + gray = PNG_sRGB_FROM_LINEAR(gray * 255); + + /* And make sure the corresponding palette entry + * matches. + */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 65535, P_LINEAR); + } + + /* The background passed to libpng, however, must be the + * sRGB value. + */ + c.index = 0; /*unused*/ + c.gray = c.red = c.green = c.blue = (png_uint_16)gray; + + /* NOTE: does this work without expanding tRNS to alpha? + * It should be the color->gray case below apparently + * doesn't. + */ + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + + output_processing = PNG_CMAP_NONE; + break; + } +#ifdef __COVERITY__ + /* Coverity claims that output_encoding cannot be 2 (P_LINEAR) + * here. + */ + back_alpha = 255; +#else + back_alpha = output_encoding == P_LINEAR ? 65535 : 255; +#endif + } + + /* output_processing means that the libpng-processed row will be + * 8-bit GA and it has to be processing to single byte color-map + * values. Entry 254 is replaced by either a completely + * transparent entry or by the background color at full + * precision (and the background color is not a simple gray + * level in this case.) + */ + expand_tRNS = 1; + output_processing = PNG_CMAP_TRANS; + background_index = 254; + + /* And set (overwrite) color-map entry 254 to the actual + * background color at full precision. + */ + png_create_colormap_entry(display, 254, back_r, back_g, back_b, + back_alpha, output_encoding); + } + + else + output_processing = PNG_CMAP_NONE; + } + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + /* 8-bit or 16-bit PNG with two channels - gray and alpha. A minimum + * of 65536 combinations. If, however, the alpha channel is to be + * removed there are only 256 possibilities if the background is gray. + * (Otherwise there is a subset of the 65536 possibilities defined by + * the triangle between black, white and the background color.) + * + * Reduce 16-bit files to 8-bit and sRGB encode the result. No need to + * worry about tRNS matching - tRNS is ignored if there is an alpha + * channel. + */ + data_encoding = P_sRGB; + + if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "gray+alpha color-map: too few entries"); + + cmap_entries = make_ga_colormap(display); + + background_index = PNG_CMAP_GA_BACKGROUND; + output_processing = PNG_CMAP_GA; + } + + else /* alpha is removed */ + { + /* Alpha must be removed as the PNG data is processed when the + * background is a color because the G and A channels are + * independent and the vector addition (non-parallel vectors) is a + * 2-D problem. + * + * This can be reduced to the same algorithm as above by making a + * colormap containing gray levels (for the opaque grays), a + * background entry (for a transparent pixel) and a set of four six + * level color values, one set for each intermediate alpha value. + * See the comments in make_ga_colormap for how this works in the + * per-pixel processing. + * + * If the background is gray, however, we only need a 256 entry gray + * level color map. It is sufficient to make the entry generated + * for the background color be exactly the color specified. + */ + if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 || + (back_r == back_g && back_g == back_b)) + { + /* Background is gray; no special processing will be required. */ + png_color_16 c; + png_uint_32 gray = back_g; + + if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "gray-alpha color-map: too few entries"); + + cmap_entries = make_gray_colormap(display); + + if (output_encoding == P_LINEAR) + { + gray = PNG_sRGB_FROM_LINEAR(gray * 255); + + /* And make sure the corresponding palette entry matches. */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 65535, P_LINEAR); + } + + /* The background passed to libpng, however, must be the sRGB + * value. + */ + c.index = 0; /*unused*/ + c.gray = c.red = c.green = c.blue = (png_uint_16)gray; + + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + + output_processing = PNG_CMAP_NONE; + } + + else + { + png_uint_32 i, a; + + /* This is the same as png_make_ga_colormap, above, except that + * the entries are all opaque. + */ + if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "ga-alpha color-map: too few entries"); + + i = 0; + while (i < 231) + { + png_uint_32 gray = (i * 256 + 115) / 231; + png_create_colormap_entry(display, i++, gray, gray, gray, + 255, P_sRGB); + } + + /* NOTE: this preserves the full precision of the application + * background color. + */ + background_index = i; + png_create_colormap_entry(display, i++, back_r, back_g, back_b, +#ifdef __COVERITY__ + /* Coverity claims that output_encoding cannot be 2 (P_LINEAR) + * here. + */ 255U, +#else + output_encoding == P_LINEAR ? 65535U : 255U, +#endif + output_encoding); + + /* For non-opaque input composite on the sRGB background - this + * requires inverting the encoding for each component. The input + * is still converted to the sRGB encoding because this is a + * reasonable approximate to the logarithmic curve of human + * visual sensitivity, at least over the narrow range which PNG + * represents. Consequently 'G' is always sRGB encoded, while + * 'A' is linear. We need the linear background colors. + */ + if (output_encoding == P_sRGB) /* else already linear */ + { + /* This may produce a value not exactly matching the + * background, but that's ok because these numbers are only + * used when alpha != 0 + */ + back_r = png_sRGB_table[back_r]; + back_g = png_sRGB_table[back_g]; + back_b = png_sRGB_table[back_b]; + } + + for (a=1; a<5; ++a) + { + unsigned int g; + + /* PNG_sRGB_FROM_LINEAR expects a 16-bit linear value scaled + * by an 8-bit alpha value (0..255). + */ + png_uint_32 alpha = 51 * a; + png_uint_32 back_rx = (255-alpha) * back_r; + png_uint_32 back_gx = (255-alpha) * back_g; + png_uint_32 back_bx = (255-alpha) * back_b; + + for (g=0; g<6; ++g) + { + png_uint_32 gray = png_sRGB_table[g*51] * alpha; + + png_create_colormap_entry(display, i++, + PNG_sRGB_FROM_LINEAR(gray + back_rx), + PNG_sRGB_FROM_LINEAR(gray + back_gx), + PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB); + } + } + + cmap_entries = i; + output_processing = PNG_CMAP_GA; + } + } + break; + + case PNG_COLOR_TYPE_RGB: + case PNG_COLOR_TYPE_RGB_ALPHA: + /* Exclude the case where the output is gray; we can always handle this + * with the cases above. + */ + if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0) + { + /* The color-map will be grayscale, so we may as well convert the + * input RGB values to a simple grayscale and use the grayscale + * code above. + * + * NOTE: calling this apparently damages the recognition of the + * transparent color in background color handling; call + * png_set_tRNS_to_alpha before png_set_background_fixed. + */ + png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1, + -1); + data_encoding = P_sRGB; + + /* The output will now be one or two 8-bit gray or gray+alpha + * channels. The more complex case arises when the input has alpha. + */ + if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) && + (output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* Both input and output have an alpha channel, so no background + * processing is required; just map the GA bytes to the right + * color-map entry. + */ + expand_tRNS = 1; + + if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "rgb[ga] color-map: too few entries"); + + cmap_entries = make_ga_colormap(display); + background_index = PNG_CMAP_GA_BACKGROUND; + output_processing = PNG_CMAP_GA; + } + + else + { + /* Either the input or the output has no alpha channel, so there + * will be no non-opaque pixels in the color-map; it will just be + * grayscale. + */ + if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "rgb[gray] color-map: too few entries"); + + /* Ideally this code would use libpng to do the gamma correction, + * but if an input alpha channel is to be removed we will hit the + * libpng bug in gamma+compose+rgb-to-gray (the double gamma + * correction bug). Fix this by dropping the gamma correction in + * this case and doing it in the palette; this will result in + * duplicate palette entries, but that's better than the + * alternative of double gamma correction. + */ + if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) && + png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0) + { + cmap_entries = make_gray_file_colormap(display); + data_encoding = P_FILE; + } + + else + cmap_entries = make_gray_colormap(display); + + /* But if the input has alpha or transparency it must be removed + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) + { + png_color_16 c; + png_uint_32 gray = back_g; + + /* We need to ensure that the application background exists in + * the colormap and that completely transparent pixels map to + * it. Achieve this simply by ensuring that the entry + * selected for the background really is the background color. + */ + if (data_encoding == P_FILE) /* from the fixup above */ + { + /* The app supplied a gray which is in output_encoding, we + * need to convert it to a value of the input (P_FILE) + * encoding then set this palette entry to the required + * output encoding. + */ + if (output_encoding == P_sRGB) + gray = png_sRGB_table[gray]; /* now P_LINEAR */ + + gray = PNG_DIV257(png_gamma_16bit_correct(gray, + png_ptr->colorspace.gamma)); /* now P_FILE */ + + /* And make sure the corresponding palette entry contains + * exactly the required sRGB value. + */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 0/*unused*/, output_encoding); + } + + else if (output_encoding == P_LINEAR) + { + gray = PNG_sRGB_FROM_LINEAR(gray * 255); + + /* And make sure the corresponding palette entry matches. + */ + png_create_colormap_entry(display, gray, back_g, back_g, + back_g, 0/*unused*/, P_LINEAR); + } + + /* The background passed to libpng, however, must be the + * output (normally sRGB) value. + */ + c.index = 0; /*unused*/ + c.gray = c.red = c.green = c.blue = (png_uint_16)gray; + + /* NOTE: the following is apparently a bug in libpng. Without + * it the transparent color recognition in + * png_set_background_fixed seems to go wrong. + */ + expand_tRNS = 1; + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + } + + output_processing = PNG_CMAP_NONE; + } + } + + else /* output is color */ + { + /* We could use png_quantize here so long as there is no transparent + * color or alpha; png_quantize ignores alpha. Easier overall just + * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube. + * Consequently we always want libpng to produce sRGB data. + */ + data_encoding = P_sRGB; + + /* Is there any transparency or alpha? */ + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->num_trans > 0) + { + /* Is there alpha in the output too? If so all four channels are + * processed into a special RGB cube with alpha support. + */ + if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + png_uint_32 r; + + if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) + png_error(png_ptr, "rgb+alpha color-map: too few entries"); + + cmap_entries = make_rgb_colormap(display); + + /* Add a transparent entry. */ + png_create_colormap_entry(display, cmap_entries, 255, 255, + 255, 0, P_sRGB); + + /* This is stored as the background index for the processing + * algorithm. + */ + background_index = cmap_entries++; + + /* Add 27 r,g,b entries each with alpha 0.5. */ + for (r=0; r<256; r = (r << 1) | 0x7f) + { + png_uint_32 g; + + for (g=0; g<256; g = (g << 1) | 0x7f) + { + png_uint_32 b; + + /* This generates components with the values 0, 127 and + * 255 + */ + for (b=0; b<256; b = (b << 1) | 0x7f) + png_create_colormap_entry(display, cmap_entries++, + r, g, b, 128, P_sRGB); + } + } + + expand_tRNS = 1; + output_processing = PNG_CMAP_RGB_ALPHA; + } + + else + { + /* Alpha/transparency must be removed. The background must + * exist in the color map (achieved by setting adding it after + * the 666 color-map). If the standard processing code will + * pick up this entry automatically that's all that is + * required; libpng can be called to do the background + * processing. + */ + unsigned int sample_size = + PNG_IMAGE_SAMPLE_SIZE(output_format); + png_uint_32 r, g, b; /* sRGB background */ + + if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries) + png_error(png_ptr, "rgb-alpha color-map: too few entries"); + + cmap_entries = make_rgb_colormap(display); + + png_create_colormap_entry(display, cmap_entries, back_r, + back_g, back_b, 0/*unused*/, output_encoding); + + if (output_encoding == P_LINEAR) + { + r = PNG_sRGB_FROM_LINEAR(back_r * 255); + g = PNG_sRGB_FROM_LINEAR(back_g * 255); + b = PNG_sRGB_FROM_LINEAR(back_b * 255); + } + + else + { + r = back_r; + g = back_g; + b = back_g; + } + + /* Compare the newly-created color-map entry with the one the + * PNG_CMAP_RGB algorithm will use. If the two entries don't + * match, add the new one and set this as the background + * index. + */ + if (memcmp((png_const_bytep)display->colormap + + sample_size * cmap_entries, + (png_const_bytep)display->colormap + + sample_size * PNG_RGB_INDEX(r,g,b), + sample_size) != 0) + { + /* The background color must be added. */ + background_index = cmap_entries++; + + /* Add 27 r,g,b entries each with created by composing with + * the background at alpha 0.5. + */ + for (r=0; r<256; r = (r << 1) | 0x7f) + { + for (g=0; g<256; g = (g << 1) | 0x7f) + { + /* This generates components with the values 0, 127 + * and 255 + */ + for (b=0; b<256; b = (b << 1) | 0x7f) + png_create_colormap_entry(display, cmap_entries++, + png_colormap_compose(display, r, P_sRGB, 128, + back_r, output_encoding), + png_colormap_compose(display, g, P_sRGB, 128, + back_g, output_encoding), + png_colormap_compose(display, b, P_sRGB, 128, + back_b, output_encoding), + 0/*unused*/, output_encoding); + } + } + + expand_tRNS = 1; + output_processing = PNG_CMAP_RGB_ALPHA; + } + + else /* background color is in the standard color-map */ + { + png_color_16 c; + + c.index = 0; /*unused*/ + c.red = (png_uint_16)back_r; + c.gray = c.green = (png_uint_16)back_g; + c.blue = (png_uint_16)back_b; + + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + + output_processing = PNG_CMAP_RGB; + } + } + } + + else /* no alpha or transparency in the input */ + { + /* Alpha in the output is irrelevant, simply map the opaque input + * pixels to the 6x6x6 color-map. + */ + if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries) + png_error(png_ptr, "rgb color-map: too few entries"); + + cmap_entries = make_rgb_colormap(display); + output_processing = PNG_CMAP_RGB; + } + } + break; + + case PNG_COLOR_TYPE_PALETTE: + /* It's already got a color-map. It may be necessary to eliminate the + * tRNS entries though. + */ + { + unsigned int num_trans = png_ptr->num_trans; + png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL; + png_const_colorp colormap = png_ptr->palette; + const int do_background = trans != NULL && + (output_format & PNG_FORMAT_FLAG_ALPHA) == 0; + unsigned int i; + + /* Just in case: */ + if (trans == NULL) + num_trans = 0; + + output_processing = PNG_CMAP_NONE; + data_encoding = P_FILE; /* Don't change from color-map indices */ + cmap_entries = png_ptr->num_palette; + if (cmap_entries > 256) + cmap_entries = 256; + + if (cmap_entries > image->colormap_entries) + png_error(png_ptr, "palette color-map: too few entries"); + + for (i=0; i < cmap_entries; ++i) + { + if (do_background != 0 && i < num_trans && trans[i] < 255) + { + if (trans[i] == 0) + png_create_colormap_entry(display, i, back_r, back_g, + back_b, 0, output_encoding); + + else + { + /* Must compose the PNG file color in the color-map entry + * on the sRGB color in 'back'. + */ + png_create_colormap_entry(display, i, + png_colormap_compose(display, colormap[i].red, P_FILE, + trans[i], back_r, output_encoding), + png_colormap_compose(display, colormap[i].green, P_FILE, + trans[i], back_g, output_encoding), + png_colormap_compose(display, colormap[i].blue, P_FILE, + trans[i], back_b, output_encoding), + output_encoding == P_LINEAR ? trans[i] * 257U : + trans[i], + output_encoding); + } + } + + else + png_create_colormap_entry(display, i, colormap[i].red, + colormap[i].green, colormap[i].blue, + i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/); + } + + /* The PNG data may have indices packed in fewer than 8 bits, it + * must be expanded if so. + */ + if (png_ptr->bit_depth < 8) + png_set_packing(png_ptr); + } + break; + + default: + png_error(png_ptr, "invalid PNG color type"); + /*NOT REACHED*/ + } + + /* Now deal with the output processing */ + if (expand_tRNS != 0 && png_ptr->num_trans > 0 && + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0) + png_set_tRNS_to_alpha(png_ptr); + + switch (data_encoding) + { + case P_sRGB: + /* Change to 8-bit sRGB */ + png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB); + /* FALL THROUGH */ + + case P_FILE: + if (png_ptr->bit_depth > 8) + png_set_scale_16(png_ptr); + break; + +#ifdef __GNUC__ + default: + png_error(png_ptr, "bad data option (internal error)"); +#endif + } + + if (cmap_entries > 256 || cmap_entries > image->colormap_entries) + png_error(png_ptr, "color map overflow (BAD internal error)"); + + image->colormap_entries = cmap_entries; + + /* Double check using the recorded background index */ + switch (output_processing) + { + case PNG_CMAP_NONE: + if (background_index != PNG_CMAP_NONE_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_GA: + if (background_index != PNG_CMAP_GA_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_TRANS: + if (background_index >= cmap_entries || + background_index != PNG_CMAP_TRANS_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_RGB: + if (background_index != PNG_CMAP_RGB_BACKGROUND) + goto bad_background; + break; + + case PNG_CMAP_RGB_ALPHA: + if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND) + goto bad_background; + break; + + default: + png_error(png_ptr, "bad processing option (internal error)"); + + bad_background: + png_error(png_ptr, "bad background index (internal error)"); + } + + display->colormap_processing = output_processing; + + return 1/*ok*/; +} + +/* The final part of the color-map read called from png_image_finish_read. */ +static int +png_image_read_and_map(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + int passes; + + /* Called when the libpng data must be transformed into the color-mapped + * form. There is a local row buffer in display->local and this routine must + * do the interlace handling. + */ + switch (png_ptr->interlaced) + { + case PNG_INTERLACE_NONE: + passes = 1; + break; + + case PNG_INTERLACE_ADAM7: + passes = PNG_INTERLACE_ADAM7_PASSES; + break; + + default: + png_error(png_ptr, "unknown interlace type"); + } + + { + png_uint_32 height = image->height; + png_uint_32 width = image->width; + int proc = display->colormap_processing; + png_bytep first_row = png_voidcast(png_bytep, display->first_row); + ptrdiff_t step_row = display->row_bytes; + int pass; + + for (pass = 0; pass < passes; ++pass) + { + unsigned int startx, stepx, stepy; + png_uint_32 y; + + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass); + stepx = PNG_PASS_COL_OFFSET(pass); + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = stepy = 1; + } + + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, display->local_row); + png_bytep outrow = first_row + y * step_row; + png_const_bytep end_row = outrow + width; + + /* Read read the libpng data into the temporary buffer. */ + png_read_row(png_ptr, inrow, NULL); + + /* Now process the row according to the processing option, note + * that the caller verifies that the format of the libpng output + * data is as required. + */ + outrow += startx; + switch (proc) + { + case PNG_CMAP_GA: + for (; outrow < end_row; outrow += stepx) + { + /* The data is always in the PNG order */ + unsigned int gray = *inrow++; + unsigned int alpha = *inrow++; + unsigned int entry; + + /* NOTE: this code is copied as a comment in + * make_ga_colormap above. Please update the + * comment if you change this code! + */ + if (alpha > 229) /* opaque */ + { + entry = (231 * gray + 128) >> 8; + } + else if (alpha < 26) /* transparent */ + { + entry = 231; + } + else /* partially opaque */ + { + entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray); + } + + *outrow = (png_byte)entry; + } + break; + + case PNG_CMAP_TRANS: + for (; outrow < end_row; outrow += stepx) + { + png_byte gray = *inrow++; + png_byte alpha = *inrow++; + + if (alpha == 0) + *outrow = PNG_CMAP_TRANS_BACKGROUND; + + else if (gray != PNG_CMAP_TRANS_BACKGROUND) + *outrow = gray; + + else + *outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1); + } + break; + + case PNG_CMAP_RGB: + for (; outrow < end_row; outrow += stepx) + { + *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]); + inrow += 3; + } + break; + + case PNG_CMAP_RGB_ALPHA: + for (; outrow < end_row; outrow += stepx) + { + unsigned int alpha = inrow[3]; + + /* Because the alpha entries only hold alpha==0.5 values + * split the processing at alpha==0.25 (64) and 0.75 + * (196). + */ + + if (alpha >= 196) + *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], + inrow[2]); + + else if (alpha < 64) + *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND; + + else + { + /* Likewise there are three entries for each of r, g + * and b. We could select the entry by popcount on + * the top two bits on those architectures that + * support it, this is what the code below does, + * crudely. + */ + unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1; + + /* Here are how the values map: + * + * 0x00 .. 0x3f -> 0 + * 0x40 .. 0xbf -> 1 + * 0xc0 .. 0xff -> 2 + * + * So, as above with the explicit alpha checks, the + * breakpoints are at 64 and 196. + */ + if (inrow[0] & 0x80) back_i += 9; /* red */ + if (inrow[0] & 0x40) back_i += 9; + if (inrow[0] & 0x80) back_i += 3; /* green */ + if (inrow[0] & 0x40) back_i += 3; + if (inrow[0] & 0x80) back_i += 1; /* blue */ + if (inrow[0] & 0x40) back_i += 1; + + *outrow = (png_byte)back_i; + } + + inrow += 4; + } + break; + + default: + break; + } + } + } + } + + return 1; +} + +static int +png_image_read_colormapped(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_controlp control = image->opaque; + png_structrp png_ptr = control->png_ptr; + png_inforp info_ptr = control->info_ptr; + + int passes = 0; /* As a flag */ + + PNG_SKIP_CHUNKS(png_ptr); + + /* Update the 'info' structure and make sure the result is as required; first + * make sure to turn on the interlace handling if it will be required + * (because it can't be turned on *after* the call to png_read_update_info!) + */ + if (display->colormap_processing == PNG_CMAP_NONE) + passes = png_set_interlace_handling(png_ptr); + + png_read_update_info(png_ptr, info_ptr); + + /* The expected output can be deduced from the colormap_processing option. */ + switch (display->colormap_processing) + { + case PNG_CMAP_NONE: + /* Output must be one channel and one byte per pixel, the output + * encoding can be anything. + */ + if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + info_ptr->color_type == PNG_COLOR_TYPE_GRAY) && + info_ptr->bit_depth == 8) + break; + + goto bad_output; + + case PNG_CMAP_TRANS: + case PNG_CMAP_GA: + /* Output must be two channels and the 'G' one must be sRGB, the latter + * can be checked with an exact number because it should have been set + * to this number above! + */ + if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + info_ptr->bit_depth == 8 && + png_ptr->screen_gamma == PNG_GAMMA_sRGB && + image->colormap_entries == 256) + break; + + goto bad_output; + + case PNG_CMAP_RGB: + /* Output must be 8-bit sRGB encoded RGB */ + if (info_ptr->color_type == PNG_COLOR_TYPE_RGB && + info_ptr->bit_depth == 8 && + png_ptr->screen_gamma == PNG_GAMMA_sRGB && + image->colormap_entries == 216) + break; + + goto bad_output; + + case PNG_CMAP_RGB_ALPHA: + /* Output must be 8-bit sRGB encoded RGBA */ + if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA && + info_ptr->bit_depth == 8 && + png_ptr->screen_gamma == PNG_GAMMA_sRGB && + image->colormap_entries == 244 /* 216 + 1 + 27 */) + break; + + /* goto bad_output; */ + /* FALL THROUGH */ + + default: + bad_output: + png_error(png_ptr, "bad color-map processing (internal error)"); + } + + /* Now read the rows. Do this here if it is possible to read directly into + * the output buffer, otherwise allocate a local row buffer of the maximum + * size libpng requires and call the relevant processing routine safely. + */ + { + png_voidp first_row = display->buffer; + ptrdiff_t row_bytes = display->row_stride; + + /* The following expression is designed to work correctly whether it gives + * a signed or an unsigned result. + */ + if (row_bytes < 0) + { + char *ptr = png_voidcast(char*, first_row); + ptr += (image->height-1) * (-row_bytes); + first_row = png_voidcast(png_voidp, ptr); + } + + display->first_row = first_row; + display->row_bytes = row_bytes; + } + + if (passes == 0) + { + int result; + png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); + + display->local_row = row; + result = png_safe_execute(image, png_image_read_and_map, display); + display->local_row = NULL; + png_free(png_ptr, row); + + return result; + } + + else + { + png_alloc_size_t row_bytes = display->row_bytes; + + while (--passes >= 0) + { + png_uint_32 y = image->height; + png_bytep row = png_voidcast(png_bytep, display->first_row); + + while (y-- > 0) + { + png_read_row(png_ptr, row, NULL); + row += row_bytes; + } + } + + return 1; + } +} + +/* Just the row reading part of png_image_read. */ +static int +png_image_read_composite(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + int passes; + + switch (png_ptr->interlaced) + { + case PNG_INTERLACE_NONE: + passes = 1; + break; + + case PNG_INTERLACE_ADAM7: + passes = PNG_INTERLACE_ADAM7_PASSES; + break; + + default: + png_error(png_ptr, "unknown interlace type"); + } + + { + png_uint_32 height = image->height; + png_uint_32 width = image->width; + ptrdiff_t step_row = display->row_bytes; + unsigned int channels = + (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; + int pass; + + for (pass = 0; pass < passes; ++pass) + { + unsigned int startx, stepx, stepy; + png_uint_32 y; + + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass) * channels; + stepx = PNG_PASS_COL_OFFSET(pass) * channels; + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = channels; + stepy = 1; + } + + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, display->local_row); + png_bytep outrow; + png_const_bytep end_row; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, inrow, NULL); + + outrow = png_voidcast(png_bytep, display->first_row); + outrow += y * step_row; + end_row = outrow + width * channels; + + /* Now do the composition on each pixel in this row. */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_byte alpha = inrow[channels]; + + if (alpha > 0) /* else no change to the output */ + { + unsigned int c; + + for (c=0; c<channels; ++c) + { + png_uint_32 component = inrow[c]; + + if (alpha < 255) /* else just use component */ + { + /* This is PNG_OPTIMIZED_ALPHA, the component value + * is a linear 8-bit value. Combine this with the + * current outrow[c] value which is sRGB encoded. + * Arithmetic here is 16-bits to preserve the output + * values correctly. + */ + component *= 257*255; /* =65535 */ + component += (255-alpha)*png_sRGB_table[outrow[c]]; + + /* So 'component' is scaled by 255*65535 and is + * therefore appropriate for the sRGB to linear + * conversion table. + */ + component = PNG_sRGB_FROM_LINEAR(component); + } + + outrow[c] = (png_byte)component; + } + } + + inrow += channels+1; /* components and alpha channel */ + } + } + } + } + + return 1; +} + +/* The do_local_background case; called when all the following transforms are to + * be done: + * + * PNG_RGB_TO_GRAY + * PNG_COMPOSITE + * PNG_GAMMA + * + * This is a work-around for the fact that both the PNG_RGB_TO_GRAY and + * PNG_COMPOSITE code performs gamma correction, so we get double gamma + * correction. The fix-up is to prevent the PNG_COMPOSITE operation from + * happening inside libpng, so this routine sees an 8 or 16-bit gray+alpha + * row and handles the removal or pre-multiplication of the alpha channel. + */ +static int +png_image_read_background(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + png_uint_32 height = image->height; + png_uint_32 width = image->width; + int pass, passes; + + /* Double check the convoluted logic below. We expect to get here with + * libpng doing rgb to gray and gamma correction but background processing + * left to the png_image_read_background function. The rows libpng produce + * might be 8 or 16-bit but should always have two channels; gray plus alpha. + */ + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) + png_error(png_ptr, "lost rgb to gray"); + + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + png_error(png_ptr, "unexpected compose"); + + if (png_get_channels(png_ptr, info_ptr) != 2) + png_error(png_ptr, "lost/gained channels"); + + /* Expect the 8-bit case to always remove the alpha channel */ + if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 && + (image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + png_error(png_ptr, "unexpected 8-bit transformation"); + + switch (png_ptr->interlaced) + { + case PNG_INTERLACE_NONE: + passes = 1; + break; + + case PNG_INTERLACE_ADAM7: + passes = PNG_INTERLACE_ADAM7_PASSES; + break; + + default: + png_error(png_ptr, "unknown interlace type"); + } + + /* Use direct access to info_ptr here because otherwise the simplified API + * would require PNG_EASY_ACCESS_SUPPORTED (just for this.) Note this is + * checking the value after libpng expansions, not the original value in the + * PNG. + */ + switch (info_ptr->bit_depth) + { + case 8: + /* 8-bit sRGB gray values with an alpha channel; the alpha channel is + * to be removed by composing on a background: either the row if + * display->background is NULL or display->background->green if not. + * Unlike the code above ALPHA_OPTIMIZED has *not* been done. + */ + { + png_bytep first_row = png_voidcast(png_bytep, display->first_row); + ptrdiff_t step_row = display->row_bytes; + + for (pass = 0; pass < passes; ++pass) + { + png_bytep row = png_voidcast(png_bytep, + display->first_row); + unsigned int startx, stepx, stepy; + png_uint_32 y; + + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass); + stepx = PNG_PASS_COL_OFFSET(pass); + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = stepy = 1; + } + + if (display->background == NULL) + { + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, + display->local_row); + png_bytep outrow = first_row + y * step_row; + png_const_bytep end_row = outrow + width; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, inrow, NULL); + + /* Now do the composition on each pixel in this row. */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_byte alpha = inrow[1]; + + if (alpha > 0) /* else no change to the output */ + { + png_uint_32 component = inrow[0]; + + if (alpha < 255) /* else just use component */ + { + /* Since PNG_OPTIMIZED_ALPHA was not set it is + * necessary to invert the sRGB transfer + * function and multiply the alpha out. + */ + component = png_sRGB_table[component] * alpha; + component += png_sRGB_table[outrow[0]] * + (255-alpha); + component = PNG_sRGB_FROM_LINEAR(component); + } + + outrow[0] = (png_byte)component; + } + + inrow += 2; /* gray and alpha channel */ + } + } + } + + else /* constant background value */ + { + png_byte background8 = display->background->green; + png_uint_16 background = png_sRGB_table[background8]; + + for (; y<height; y += stepy) + { + png_bytep inrow = png_voidcast(png_bytep, + display->local_row); + png_bytep outrow = first_row + y * step_row; + png_const_bytep end_row = outrow + width; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, inrow, NULL); + + /* Now do the composition on each pixel in this row. */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_byte alpha = inrow[1]; + + if (alpha > 0) /* else use background */ + { + png_uint_32 component = inrow[0]; + + if (alpha < 255) /* else just use component */ + { + component = png_sRGB_table[component] * alpha; + component += background * (255-alpha); + component = PNG_sRGB_FROM_LINEAR(component); + } + + outrow[0] = (png_byte)component; + } + + else + outrow[0] = background8; + + inrow += 2; /* gray and alpha channel */ + } + + row += display->row_bytes; + } + } + } + } + break; + + case 16: + /* 16-bit linear with pre-multiplied alpha; the pre-multiplication must + * still be done and, maybe, the alpha channel removed. This code also + * handles the alpha-first option. + */ + { + png_uint_16p first_row = png_voidcast(png_uint_16p, + display->first_row); + /* The division by two is safe because the caller passed in a + * stride which was multiplied by 2 (below) to get row_bytes. + */ + ptrdiff_t step_row = display->row_bytes / 2; + int preserve_alpha = (image->format & PNG_FORMAT_FLAG_ALPHA) != 0; + unsigned int outchannels = 1+preserve_alpha; + int swap_alpha = 0; + +# ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED + if (preserve_alpha != 0 && + (image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + swap_alpha = 1; +# endif + + for (pass = 0; pass < passes; ++pass) + { + unsigned int startx, stepx, stepy; + png_uint_32 y; + + /* The 'x' start and step are adjusted to output components here. + */ + if (png_ptr->interlaced == PNG_INTERLACE_ADAM7) + { + /* The row may be empty for a short image: */ + if (PNG_PASS_COLS(width, pass) == 0) + continue; + + startx = PNG_PASS_START_COL(pass) * outchannels; + stepx = PNG_PASS_COL_OFFSET(pass) * outchannels; + y = PNG_PASS_START_ROW(pass); + stepy = PNG_PASS_ROW_OFFSET(pass); + } + + else + { + y = 0; + startx = 0; + stepx = outchannels; + stepy = 1; + } + + for (; y<height; y += stepy) + { + png_const_uint_16p inrow; + png_uint_16p outrow = first_row + y*step_row; + png_uint_16p end_row = outrow + width * outchannels; + + /* Read the row, which is packed: */ + png_read_row(png_ptr, png_voidcast(png_bytep, + display->local_row), NULL); + inrow = png_voidcast(png_const_uint_16p, display->local_row); + + /* Now do the pre-multiplication on each pixel in this row. + */ + outrow += startx; + for (; outrow < end_row; outrow += stepx) + { + png_uint_32 component = inrow[0]; + png_uint_16 alpha = inrow[1]; + + if (alpha > 0) /* else 0 */ + { + if (alpha < 65535) /* else just use component */ + { + component *= alpha; + component += 32767; + component /= 65535; + } + } + + else + component = 0; + + outrow[swap_alpha] = (png_uint_16)component; + if (preserve_alpha != 0) + outrow[1 ^ swap_alpha] = alpha; + + inrow += 2; /* components and alpha channel */ + } + } + } + } + break; + +#ifdef __GNUC__ + default: + png_error(png_ptr, "unexpected bit depth"); +#endif + } + + return 1; +} + +/* The guts of png_image_finish_read as a png_safe_execute callback. */ +static int +png_image_read_direct(png_voidp argument) +{ + png_image_read_control *display = png_voidcast(png_image_read_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + + png_uint_32 format = image->format; + int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0; + int do_local_compose = 0; + int do_local_background = 0; /* to avoid double gamma correction bug */ + int passes = 0; + + /* Add transforms to ensure the correct output format is produced then check + * that the required implementation support is there. Always expand; always + * need 8 bits minimum, no palette and expanded tRNS. + */ + png_set_expand(png_ptr); + + /* Now check the format to see if it was modified. */ + { + png_uint_32 base_format = png_image_format(png_ptr) & + ~PNG_FORMAT_FLAG_COLORMAP /* removed by png_set_expand */; + png_uint_32 change = format ^ base_format; + png_fixed_point output_gamma; + int mode; /* alpha mode */ + + /* Do this first so that we have a record if rgb to gray is happening. */ + if ((change & PNG_FORMAT_FLAG_COLOR) != 0) + { + /* gray<->color transformation required. */ + if ((format & PNG_FORMAT_FLAG_COLOR) != 0) + png_set_gray_to_rgb(png_ptr); + + else + { + /* libpng can't do both rgb to gray and + * background/pre-multiplication if there is also significant gamma + * correction, because both operations require linear colors and + * the code only supports one transform doing the gamma correction. + * Handle this by doing the pre-multiplication or background + * operation in this code, if necessary. + * + * TODO: fix this by rewriting pngrtran.c (!) + * + * For the moment (given that fixing this in pngrtran.c is an + * enormous change) 'do_local_background' is used to indicate that + * the problem exists. + */ + if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) + do_local_background = 1/*maybe*/; + + png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, + PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT); + } + + change &= ~PNG_FORMAT_FLAG_COLOR; + } + + /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise. + */ + { + png_fixed_point input_gamma_default; + + if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 && + (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0) + input_gamma_default = PNG_GAMMA_LINEAR; + else + input_gamma_default = PNG_DEFAULT_sRGB; + + /* Call png_set_alpha_mode to set the default for the input gamma; the + * output gamma is set by a second call below. + */ + png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default); + } + + if (linear != 0) + { + /* If there *is* an alpha channel in the input it must be multiplied + * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG. + */ + if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) + mode = PNG_ALPHA_STANDARD; /* associated alpha */ + + else + mode = PNG_ALPHA_PNG; + + output_gamma = PNG_GAMMA_LINEAR; + } + + else + { + mode = PNG_ALPHA_PNG; + output_gamma = PNG_DEFAULT_sRGB; + } + + /* If 'do_local_background' is set check for the presence of gamma + * correction; this is part of the work-round for the libpng bug + * described above. + * + * TODO: fix libpng and remove this. + */ + if (do_local_background != 0) + { + png_fixed_point gtest; + + /* This is 'png_gamma_threshold' from pngrtran.c; the test used for + * gamma correction, the screen gamma hasn't been set on png_struct + * yet; it's set below. png_struct::gamma, however, is set to the + * final value. + */ + if (png_muldiv(>est, output_gamma, png_ptr->colorspace.gamma, + PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0) + do_local_background = 0; + + else if (mode == PNG_ALPHA_STANDARD) + { + do_local_background = 2/*required*/; + mode = PNG_ALPHA_PNG; /* prevent libpng doing it */ + } + + /* else leave as 1 for the checks below */ + } + + /* If the bit-depth changes then handle that here. */ + if ((change & PNG_FORMAT_FLAG_LINEAR) != 0) + { + if (linear != 0 /*16-bit output*/) + png_set_expand_16(png_ptr); + + else /* 8-bit output */ + png_set_scale_16(png_ptr); + + change &= ~PNG_FORMAT_FLAG_LINEAR; + } + + /* Now the background/alpha channel changes. */ + if ((change & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* Removing an alpha channel requires composition for the 8-bit + * formats; for the 16-bit it is already done, above, by the + * pre-multiplication and the channel just needs to be stripped. + */ + if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* If RGB->gray is happening the alpha channel must be left and the + * operation completed locally. + * + * TODO: fix libpng and remove this. + */ + if (do_local_background != 0) + do_local_background = 2/*required*/; + + /* 16-bit output: just remove the channel */ + else if (linear != 0) /* compose on black (well, pre-multiply) */ + png_set_strip_alpha(png_ptr); + + /* 8-bit output: do an appropriate compose */ + else if (display->background != NULL) + { + png_color_16 c; + + c.index = 0; /*unused*/ + c.red = display->background->red; + c.green = display->background->green; + c.blue = display->background->blue; + c.gray = display->background->green; + + /* This is always an 8-bit sRGB value, using the 'green' channel + * for gray is much better than calculating the luminance here; + * we can get off-by-one errors in that calculation relative to + * the app expectations and that will show up in transparent + * pixels. + */ + png_set_background_fixed(png_ptr, &c, + PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/, + 0/*gamma: not used*/); + } + + else /* compose on row: implemented below. */ + { + do_local_compose = 1; + /* This leaves the alpha channel in the output, so it has to be + * removed by the code below. Set the encoding to the 'OPTIMIZE' + * one so the code only has to hack on the pixels that require + * composition. + */ + mode = PNG_ALPHA_OPTIMIZED; + } + } + + else /* output needs an alpha channel */ + { + /* This is tricky because it happens before the swap operation has + * been accomplished; however, the swap does *not* swap the added + * alpha channel (weird API), so it must be added in the correct + * place. + */ + png_uint_32 filler; /* opaque filler */ + int where; + + if (linear != 0) + filler = 65535; + + else + filler = 255; + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + where = PNG_FILLER_BEFORE; + change &= ~PNG_FORMAT_FLAG_AFIRST; + } + + else +#endif + where = PNG_FILLER_AFTER; + + png_set_add_alpha(png_ptr, filler, where); + } + + /* This stops the (irrelevant) call to swap_alpha below. */ + change &= ~PNG_FORMAT_FLAG_ALPHA; + } + + /* Now set the alpha mode correctly; this is always done, even if there is + * no alpha channel in either the input or the output because it correctly + * sets the output gamma. + */ + png_set_alpha_mode_fixed(png_ptr, mode, output_gamma); + +# ifdef PNG_FORMAT_BGR_SUPPORTED + if ((change & PNG_FORMAT_FLAG_BGR) != 0) + { + /* Check only the output format; PNG is never BGR; don't do this if + * the output is gray, but fix up the 'format' value in that case. + */ + if ((format & PNG_FORMAT_FLAG_COLOR) != 0) + png_set_bgr(png_ptr); + + else + format &= ~PNG_FORMAT_FLAG_BGR; + + change &= ~PNG_FORMAT_FLAG_BGR; + } +# endif + +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if ((change & PNG_FORMAT_FLAG_AFIRST) != 0) + { + /* Only relevant if there is an alpha channel - it's particularly + * important to handle this correctly because do_local_compose may + * be set above and then libpng will keep the alpha channel for this + * code to remove. + */ + if ((format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* Disable this if doing a local background, + * TODO: remove this when local background is no longer required. + */ + if (do_local_background != 2) + png_set_swap_alpha(png_ptr); + } + + else + format &= ~PNG_FORMAT_FLAG_AFIRST; + + change &= ~PNG_FORMAT_FLAG_AFIRST; + } +# endif + + /* If the *output* is 16-bit then we need to check for a byte-swap on this + * architecture. + */ + if (linear != 0) + { + PNG_CONST png_uint_16 le = 0x0001; + + if ((*(png_const_bytep) & le) != 0) + png_set_swap(png_ptr); + } + + /* If change is not now 0 some transformation is missing - error out. */ + if (change != 0) + png_error(png_ptr, "png_read_image: unsupported transformation"); + } + + PNG_SKIP_CHUNKS(png_ptr); + + /* Update the 'info' structure and make sure the result is as required; first + * make sure to turn on the interlace handling if it will be required + * (because it can't be turned on *after* the call to png_read_update_info!) + * + * TODO: remove the do_local_background fixup below. + */ + if (do_local_compose == 0 && do_local_background != 2) + passes = png_set_interlace_handling(png_ptr); + + png_read_update_info(png_ptr, info_ptr); + + { + png_uint_32 info_format = 0; + + if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + info_format |= PNG_FORMAT_FLAG_COLOR; + + if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + /* do_local_compose removes this channel below. */ + if (do_local_compose == 0) + { + /* do_local_background does the same if required. */ + if (do_local_background != 2 || + (format & PNG_FORMAT_FLAG_ALPHA) != 0) + info_format |= PNG_FORMAT_FLAG_ALPHA; + } + } + + else if (do_local_compose != 0) /* internal error */ + png_error(png_ptr, "png_image_read: alpha channel lost"); + + if (info_ptr->bit_depth == 16) + info_format |= PNG_FORMAT_FLAG_LINEAR; + +#ifdef PNG_FORMAT_BGR_SUPPORTED + if ((png_ptr->transformations & PNG_BGR) != 0) + info_format |= PNG_FORMAT_FLAG_BGR; +#endif + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (do_local_background == 2) + { + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + info_format |= PNG_FORMAT_FLAG_AFIRST; + } + + if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 || + ((png_ptr->transformations & PNG_ADD_ALPHA) != 0 && + (png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0)) + { + if (do_local_background == 2) + png_error(png_ptr, "unexpected alpha swap transformation"); + + info_format |= PNG_FORMAT_FLAG_AFIRST; + } +# endif + + /* This is actually an internal error. */ + if (info_format != format) + png_error(png_ptr, "png_read_image: invalid transformations"); + } + + /* Now read the rows. If do_local_compose is set then it is necessary to use + * a local row buffer. The output will be GA, RGBA or BGRA and must be + * converted to G, RGB or BGR as appropriate. The 'local_row' member of the + * display acts as a flag. + */ + { + png_voidp first_row = display->buffer; + ptrdiff_t row_bytes = display->row_stride; + + if (linear != 0) + row_bytes *= 2; + + /* The following expression is designed to work correctly whether it gives + * a signed or an unsigned result. + */ + if (row_bytes < 0) + { + char *ptr = png_voidcast(char*, first_row); + ptr += (image->height-1) * (-row_bytes); + first_row = png_voidcast(png_voidp, ptr); + } + + display->first_row = first_row; + display->row_bytes = row_bytes; + } + + if (do_local_compose != 0) + { + int result; + png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); + + display->local_row = row; + result = png_safe_execute(image, png_image_read_composite, display); + display->local_row = NULL; + png_free(png_ptr, row); + + return result; + } + + else if (do_local_background == 2) + { + int result; + png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr)); + + display->local_row = row; + result = png_safe_execute(image, png_image_read_background, display); + display->local_row = NULL; + png_free(png_ptr, row); + + return result; + } + + else + { + png_alloc_size_t row_bytes = display->row_bytes; + + while (--passes >= 0) + { + png_uint_32 y = image->height; + png_bytep row = png_voidcast(png_bytep, display->first_row); + + while (y-- > 0) + { + png_read_row(png_ptr, row, NULL); + row += row_bytes; + } + } + + return 1; + } +} + +int PNGAPI +png_image_finish_read(png_imagep image, png_const_colorp background, + void *buffer, png_int_32 row_stride, void *colormap) +{ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + /* Check for row_stride overflow. This check is not performed on the + * original PNG format because it may not occur in the output PNG format + * and libpng deals with the issues of reading the original. + */ + const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); + + if (image->width <= 0x7FFFFFFFU/channels) /* no overflow */ + { + png_uint_32 check; + const png_uint_32 png_row_stride = image->width * channels; + + if (row_stride == 0) + row_stride = (png_int_32)/*SAFE*/png_row_stride; + + if (row_stride < 0) + check = -row_stride; + + else + check = row_stride; + + if (image->opaque != NULL && buffer != NULL && check >= png_row_stride) + { + /* Now check for overflow of the image buffer calculation; this + * limits the whole image size to 32 bits for API compatibility with + * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. + */ + if (image->height <= 0xFFFFFFFF/png_row_stride) + { + if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 || + (image->colormap_entries > 0 && colormap != NULL)) + { + int result; + png_image_read_control display; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.background = background; + display.local_row = NULL; + + /* Choose the correct 'end' routine; for the color-map case + * all the setup has already been done. + */ + if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0) + result = png_safe_execute(image, + png_image_read_colormap, &display) && + png_safe_execute(image, + png_image_read_colormapped, &display); + + else + result = + png_safe_execute(image, + png_image_read_direct, &display); + + png_image_free(image); + return result; + } + + else + return png_image_error(image, + "png_image_finish_read[color-map]: no color-map"); + } + + else + return png_image_error(image, + "png_image_finish_read: image too large"); + } + + else + return png_image_error(image, + "png_image_finish_read: invalid argument"); + } + + else + return png_image_error(image, + "png_image_finish_read: row_stride too large"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_finish_read: damaged PNG_IMAGE_VERSION"); + + return 0; +} + +#endif /* SIMPLIFIED_READ */ +#endif /* READ */ diff --git a/thirdparty/libpng/pngrio.c b/thirdparty/libpng/pngrio.c new file mode 100644 index 0000000000..5101d54a62 --- /dev/null +++ b/thirdparty/libpng/pngrio.c @@ -0,0 +1,120 @@ + +/* pngrio.c - functions for data input + * + * Last changed in libpng 1.6.17 [March 26, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all input. Users who need + * special handling are expected to write a function that has the same + * arguments as this and performs a similar function, but that possibly + * has a different input method. Note that you shouldn't change this + * function, but rather write a replacement function and then make + * libpng use it at run time with png_set_read_fn(...). + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* Read the data from whatever input you are using. The default routine + * reads from a file pointer. Note that this routine sometimes gets called + * with very small lengths, so you should implement some kind of simple + * buffering if you are using unbuffered reads. This should never be asked + * to read more than 64K on a 16-bit machine. + */ +void /* PRIVATE */ +png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length) +{ + png_debug1(4, "reading %d bytes", (int)length); + + if (png_ptr->read_data_fn != NULL) + (*(png_ptr->read_data_fn))(png_ptr, data, length); + + else + png_error(png_ptr, "Call to NULL read function"); +} + +#ifdef PNG_STDIO_SUPPORTED +/* This is the function that does the actual reading of data. If you are + * not reading from a standard C stream, you should create a replacement + * read_data function and use it at run time with png_set_read_fn(), rather + * than changing the library. + */ +void PNGCBAPI +png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + + if (png_ptr == NULL) + return; + + /* fread() returns 0 on error, so it is OK to store this in a png_size_t + * instead of an int, which is what fread() actually returns. + */ + check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr)); + + if (check != length) + png_error(png_ptr, "Read Error"); +} +#endif + +/* This function allows the application to supply a new input function + * for libpng if standard C streams aren't being used. + * + * This function takes as its arguments: + * + * png_ptr - pointer to a png input data structure + * + * io_ptr - pointer to user supplied structure containing info about + * the input functions. May be NULL. + * + * read_data_fn - pointer to a new input function that takes as its + * arguments a pointer to a png_struct, a pointer to + * a location where input data can be stored, and a 32-bit + * unsigned int that is the number of bytes to be read. + * To exit and output any fatal error messages the new write + * function should call png_error(png_ptr, "Error msg"). + * May be NULL, in which case libpng's default function will + * be used. + */ +void PNGAPI +png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = io_ptr; + +#ifdef PNG_STDIO_SUPPORTED + if (read_data_fn != NULL) + png_ptr->read_data_fn = read_data_fn; + + else + png_ptr->read_data_fn = png_default_read_data; +#else + png_ptr->read_data_fn = read_data_fn; +#endif + +#ifdef PNG_WRITE_SUPPORTED + /* It is an error to write to a read device */ + if (png_ptr->write_data_fn != NULL) + { + png_ptr->write_data_fn = NULL; + png_warning(png_ptr, + "Can't set both read_data_fn and write_data_fn in the" + " same structure"); + } +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->output_flush_fn = NULL; +#endif +} +#endif /* READ */ diff --git a/thirdparty/libpng/pngrtran.c b/thirdparty/libpng/pngrtran.c new file mode 100644 index 0000000000..3138147aff --- /dev/null +++ b/thirdparty/libpng/pngrtran.c @@ -0,0 +1,5000 @@ + +/* pngrtran.c - transforms the data in a row for PNG readers + * + * Last changed in libpng 1.6.22 [May 26, 2016] + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains functions optionally called by an application + * in order to tell libpng how to handle data when reading a PNG. + * Transformations that are used in both reading and writing are + * in pngtrans.c. + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* Set the action on getting a CRC error for an ancillary or critical chunk. */ +void PNGAPI +png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action) +{ + png_debug(1, "in png_set_crc_action"); + + if (png_ptr == NULL) + return; + + /* Tell libpng how we react to CRC errors in critical chunks */ + switch (crit_action) + { + case PNG_CRC_NO_CHANGE: /* Leave setting as is */ + break; + + case PNG_CRC_WARN_USE: /* Warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; + break; + + case PNG_CRC_QUIET_USE: /* Quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | + PNG_FLAG_CRC_CRITICAL_IGNORE; + break; + + case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ + png_warning(png_ptr, + "Can't discard critical data on CRC error"); + case PNG_CRC_ERROR_QUIT: /* Error/quit */ + + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + break; + } + + /* Tell libpng how we react to CRC errors in ancillary chunks */ + switch (ancil_action) + { + case PNG_CRC_NO_CHANGE: /* Leave setting as is */ + break; + + case PNG_CRC_WARN_USE: /* Warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; + break; + + case PNG_CRC_QUIET_USE: /* Quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | + PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + + case PNG_CRC_ERROR_QUIT: /* Error/quit */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + + case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ + + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + break; + } +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* Is it OK to set a transformation now? Only if png_start_read_image or + * png_read_update_info have not been called. It is not necessary for the IHDR + * to have been read in all cases; the need_IHDR parameter allows for this + * check too. + */ +static int +png_rtran_ok(png_structrp png_ptr, int need_IHDR) +{ + if (png_ptr != NULL) + { + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0) + png_app_error(png_ptr, + "invalid after png_start_read_image or png_read_update_info"); + + else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_app_error(png_ptr, "invalid before the PNG header has been read"); + + else + { + /* Turn on failure to initialize correctly for all transforms. */ + png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; + + return 1; /* Ok */ + } + } + + return 0; /* no png_error possible! */ +} +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Handle alpha and tRNS via a background color */ +void PNGFAPI +png_set_background_fixed(png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, png_fixed_point background_gamma) +{ + png_debug(1, "in png_set_background_fixed"); + + if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL) + return; + + if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) + { + png_warning(png_ptr, "Application must supply a known background gamma"); + return; + } + + png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + png_ptr->background = *background_color; + png_ptr->background_gamma = background_gamma; + png_ptr->background_gamma_type = (png_byte)(background_gamma_code); + if (need_expand != 0) + png_ptr->transformations |= PNG_BACKGROUND_EXPAND; + else + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_background(png_structrp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma) +{ + png_set_background_fixed(png_ptr, background_color, background_gamma_code, + need_expand, png_fixed(png_ptr, background_gamma, "png_set_background")); +} +# endif /* FLOATING_POINT */ +#endif /* READ_BACKGROUND */ + +/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the + * one that pngrtran does first (scale) happens. This is necessary to allow the + * TRANSFORM and API behavior to be somewhat consistent, and it's simpler. + */ +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +void PNGAPI +png_set_scale_16(png_structrp png_ptr) +{ + png_debug(1, "in png_set_scale_16"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_SCALE_16_TO_8; +} +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +/* Chop 16-bit depth files to 8-bit depth */ +void PNGAPI +png_set_strip_16(png_structrp png_ptr) +{ + png_debug(1, "in png_set_strip_16"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_16_TO_8; +} +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +void PNGAPI +png_set_strip_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_strip_alpha"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_STRIP_ALPHA; +} +#endif + +#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED) +static png_fixed_point +translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma, + int is_screen) +{ + /* Check for flag values. The main reason for having the old Mac value as a + * flag is that it is pretty near impossible to work out what the correct + * value is from Apple documentation - a working Mac system is needed to + * discover the value! + */ + if (output_gamma == PNG_DEFAULT_sRGB || + output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB) + { + /* If there is no sRGB support this just sets the gamma to the standard + * sRGB value. (This is a side effect of using this function!) + */ +# ifdef PNG_READ_sRGB_SUPPORTED + png_ptr->flags |= PNG_FLAG_ASSUME_sRGB; +# else + PNG_UNUSED(png_ptr) +# endif + if (is_screen != 0) + output_gamma = PNG_GAMMA_sRGB; + else + output_gamma = PNG_GAMMA_sRGB_INVERSE; + } + + else if (output_gamma == PNG_GAMMA_MAC_18 || + output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18) + { + if (is_screen != 0) + output_gamma = PNG_GAMMA_MAC_OLD; + else + output_gamma = PNG_GAMMA_MAC_INVERSE; + } + + return output_gamma; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +static png_fixed_point +convert_gamma_value(png_structrp png_ptr, double output_gamma) +{ + /* The following silently ignores cases where fixed point (times 100,000) + * gamma values are passed to the floating point API. This is safe and it + * means the fixed point constants work just fine with the floating point + * API. The alternative would just lead to undetected errors and spurious + * bug reports. Negative values fail inside the _fixed API unless they + * correspond to the flag values. + */ + if (output_gamma > 0 && output_gamma < 128) + output_gamma *= PNG_FP_1; + + /* This preserves -1 and -2 exactly: */ + output_gamma = floor(output_gamma + .5); + + if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN) + png_fixed_error(png_ptr, "gamma value"); + + return (png_fixed_point)output_gamma; +} +# endif +#endif /* READ_ALPHA_MODE || READ_GAMMA */ + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +void PNGFAPI +png_set_alpha_mode_fixed(png_structrp png_ptr, int mode, + png_fixed_point output_gamma) +{ + int compose = 0; + png_fixed_point file_gamma; + + png_debug(1, "in png_set_alpha_mode"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/); + + /* Validate the value to ensure it is in a reasonable range. The value + * is expected to be 1 or greater, but this range test allows for some + * viewing correction values. The intent is to weed out users of this API + * who use the inverse of the gamma value accidentally! Since some of these + * values are reasonable this may have to be changed: + * + * 1.6.x: changed from 0.07..3 to 0.01..100 (to accomodate the optimal 16-bit + * gamma of 36, and its reciprocal.) + */ + if (output_gamma < 1000 || output_gamma > 10000000) + png_error(png_ptr, "output gamma out of expected range"); + + /* The default file gamma is the inverse of the output gamma; the output + * gamma may be changed below so get the file value first: + */ + file_gamma = png_reciprocal(output_gamma); + + /* There are really 8 possibilities here, composed of any combination + * of: + * + * premultiply the color channels + * do not encode non-opaque pixels + * encode the alpha as well as the color channels + * + * The differences disappear if the input/output ('screen') gamma is 1.0, + * because then the encoding is a no-op and there is only the choice of + * premultiplying the color channels or not. + * + * png_set_alpha_mode and png_set_background interact because both use + * png_compose to do the work. Calling both is only useful when + * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along + * with a default gamma value. Otherwise PNG_COMPOSE must not be set. + */ + switch (mode) + { + case PNG_ALPHA_PNG: /* default: png standard */ + /* No compose, but it may be set by png_set_background! */ + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + break; + + case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */ + compose = 1; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + /* The output is linear: */ + output_gamma = PNG_FP_1; + break; + + case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */ + compose = 1; + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA; + /* output_gamma records the encoding of opaque pixels! */ + break; + + case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */ + compose = 1; + png_ptr->transformations |= PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + break; + + default: + png_error(png_ptr, "invalid alpha mode"); + } + + /* Only set the default gamma if the file gamma has not been set (this has + * the side effect that the gamma in a second call to png_set_alpha_mode will + * be ignored.) + */ + if (png_ptr->colorspace.gamma == 0) + { + png_ptr->colorspace.gamma = file_gamma; + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + } + + /* But always set the output gamma: */ + png_ptr->screen_gamma = output_gamma; + + /* Finally, if pre-multiplying, set the background fields to achieve the + * desired result. + */ + if (compose != 0) + { + /* And obtain alpha pre-multiplication by composing on black: */ + memset(&png_ptr->background, 0, (sizeof png_ptr->background)); + png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */ + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; + + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + png_error(png_ptr, + "conflicting calls to set alpha mode and background"); + + png_ptr->transformations |= PNG_COMPOSE; + } +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma) +{ + png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr, + output_gamma)); +} +# endif +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* Dither file to 8-bit. Supply a palette, the current number + * of elements in the palette, the maximum number of elements + * allowed, and a histogram if possible. If the current number + * of colors is greater than the maximum number, the palette will be + * modified to fit in the maximum number. "full_quantize" indicates + * whether we need a quantizing cube set up for RGB images, or if we + * simply are reducing the number of colors in a paletted image. + */ + +typedef struct png_dsort_struct +{ + struct png_dsort_struct * next; + png_byte left; + png_byte right; +} png_dsort; +typedef png_dsort * png_dsortp; +typedef png_dsort * * png_dsortpp; + +void PNGAPI +png_set_quantize(png_structrp png_ptr, png_colorp palette, + int num_palette, int maximum_colors, png_const_uint_16p histogram, + int full_quantize) +{ + png_debug(1, "in png_set_quantize"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_QUANTIZE; + + if (full_quantize == 0) + { + int i; + + png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * (sizeof (png_byte)))); + for (i = 0; i < num_palette; i++) + png_ptr->quantize_index[i] = (png_byte)i; + } + + if (num_palette > maximum_colors) + { + if (histogram != NULL) + { + /* This is easy enough, just throw out the least used colors. + * Perhaps not the best solution, but good enough. + */ + + int i; + + /* Initialize an array to sort colors */ + png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * (sizeof (png_byte)))); + + /* Initialize the quantize_sort array */ + for (i = 0; i < num_palette; i++) + png_ptr->quantize_sort[i] = (png_byte)i; + + /* Find the least used palette entries by starting a + * bubble sort, and running it until we have sorted + * out enough colors. Note that we don't care about + * sorting all the colors, just finding which are + * least used. + */ + + for (i = num_palette - 1; i >= maximum_colors; i--) + { + int done; /* To stop early if the list is pre-sorted */ + int j; + + done = 1; + for (j = 0; j < i; j++) + { + if (histogram[png_ptr->quantize_sort[j]] + < histogram[png_ptr->quantize_sort[j + 1]]) + { + png_byte t; + + t = png_ptr->quantize_sort[j]; + png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1]; + png_ptr->quantize_sort[j + 1] = t; + done = 0; + } + } + + if (done != 0) + break; + } + + /* Swap the palette around, and set up a table, if necessary */ + if (full_quantize != 0) + { + int j = num_palette; + + /* Put all the useful colors within the max, but don't + * move the others. + */ + for (i = 0; i < maximum_colors; i++) + { + if ((int)png_ptr->quantize_sort[i] >= maximum_colors) + { + do + j--; + while ((int)png_ptr->quantize_sort[j] >= maximum_colors); + + palette[i] = palette[j]; + } + } + } + else + { + int j = num_palette; + + /* Move all the used colors inside the max limit, and + * develop a translation table. + */ + for (i = 0; i < maximum_colors; i++) + { + /* Only move the colors we need to */ + if ((int)png_ptr->quantize_sort[i] >= maximum_colors) + { + png_color tmp_color; + + do + j--; + while ((int)png_ptr->quantize_sort[j] >= maximum_colors); + + tmp_color = palette[j]; + palette[j] = palette[i]; + palette[i] = tmp_color; + /* Indicate where the color went */ + png_ptr->quantize_index[j] = (png_byte)i; + png_ptr->quantize_index[i] = (png_byte)j; + } + } + + /* Find closest color for those colors we are not using */ + for (i = 0; i < num_palette; i++) + { + if ((int)png_ptr->quantize_index[i] >= maximum_colors) + { + int min_d, k, min_k, d_index; + + /* Find the closest color to one we threw out */ + d_index = png_ptr->quantize_index[i]; + min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); + for (k = 1, min_k = 0; k < maximum_colors; k++) + { + int d; + + d = PNG_COLOR_DIST(palette[d_index], palette[k]); + + if (d < min_d) + { + min_d = d; + min_k = k; + } + } + /* Point to closest color */ + png_ptr->quantize_index[i] = (png_byte)min_k; + } + } + } + png_free(png_ptr, png_ptr->quantize_sort); + png_ptr->quantize_sort = NULL; + } + else + { + /* This is much harder to do simply (and quickly). Perhaps + * we need to go through a median cut routine, but those + * don't always behave themselves with only a few colors + * as input. So we will just find the closest two colors, + * and throw out one of them (chosen somewhat randomly). + * [We don't understand this at all, so if someone wants to + * work on improving it, be our guest - AED, GRP] + */ + int i; + int max_d; + int num_new_palette; + png_dsortp t; + png_dsortpp hash; + + t = NULL; + + /* Initialize palette index arrays */ + png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * (sizeof (png_byte)))); + png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * (sizeof (png_byte)))); + + /* Initialize the sort array */ + for (i = 0; i < num_palette; i++) + { + png_ptr->index_to_palette[i] = (png_byte)i; + png_ptr->palette_to_index[i] = (png_byte)i; + } + + hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 * + (sizeof (png_dsortp)))); + + num_new_palette = num_palette; + + /* Initial wild guess at how far apart the farthest pixel + * pair we will be eliminating will be. Larger + * numbers mean more areas will be allocated, Smaller + * numbers run the risk of not saving enough data, and + * having to do this all over again. + * + * I have not done extensive checking on this number. + */ + max_d = 96; + + while (num_new_palette > maximum_colors) + { + for (i = 0; i < num_new_palette - 1; i++) + { + int j; + + for (j = i + 1; j < num_new_palette; j++) + { + int d; + + d = PNG_COLOR_DIST(palette[i], palette[j]); + + if (d <= max_d) + { + + t = (png_dsortp)png_malloc_warn(png_ptr, + (png_uint_32)(sizeof (png_dsort))); + + if (t == NULL) + break; + + t->next = hash[d]; + t->left = (png_byte)i; + t->right = (png_byte)j; + hash[d] = t; + } + } + if (t == NULL) + break; + } + + if (t != NULL) + for (i = 0; i <= max_d; i++) + { + if (hash[i] != NULL) + { + png_dsortp p; + + for (p = hash[i]; p; p = p->next) + { + if ((int)png_ptr->index_to_palette[p->left] + < num_new_palette && + (int)png_ptr->index_to_palette[p->right] + < num_new_palette) + { + int j, next_j; + + if (num_new_palette & 0x01) + { + j = p->left; + next_j = p->right; + } + else + { + j = p->right; + next_j = p->left; + } + + num_new_palette--; + palette[png_ptr->index_to_palette[j]] + = palette[num_new_palette]; + if (full_quantize == 0) + { + int k; + + for (k = 0; k < num_palette; k++) + { + if (png_ptr->quantize_index[k] == + png_ptr->index_to_palette[j]) + png_ptr->quantize_index[k] = + png_ptr->index_to_palette[next_j]; + + if ((int)png_ptr->quantize_index[k] == + num_new_palette) + png_ptr->quantize_index[k] = + png_ptr->index_to_palette[j]; + } + } + + png_ptr->index_to_palette[png_ptr->palette_to_index + [num_new_palette]] = png_ptr->index_to_palette[j]; + + png_ptr->palette_to_index[png_ptr->index_to_palette[j]] + = png_ptr->palette_to_index[num_new_palette]; + + png_ptr->index_to_palette[j] = + (png_byte)num_new_palette; + + png_ptr->palette_to_index[num_new_palette] = + (png_byte)j; + } + if (num_new_palette <= maximum_colors) + break; + } + if (num_new_palette <= maximum_colors) + break; + } + } + + for (i = 0; i < 769; i++) + { + if (hash[i] != NULL) + { + png_dsortp p = hash[i]; + while (p) + { + t = p->next; + png_free(png_ptr, p); + p = t; + } + } + hash[i] = 0; + } + max_d += 96; + } + png_free(png_ptr, hash); + png_free(png_ptr, png_ptr->palette_to_index); + png_free(png_ptr, png_ptr->index_to_palette); + png_ptr->palette_to_index = NULL; + png_ptr->index_to_palette = NULL; + } + num_palette = maximum_colors; + } + if (png_ptr->palette == NULL) + { + png_ptr->palette = palette; + } + png_ptr->num_palette = (png_uint_16)num_palette; + + if (full_quantize != 0) + { + int i; + png_bytep distance; + int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS + + PNG_QUANTIZE_BLUE_BITS; + int num_red = (1 << PNG_QUANTIZE_RED_BITS); + int num_green = (1 << PNG_QUANTIZE_GREEN_BITS); + int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS); + png_size_t num_entries = ((png_size_t)1 << total_bits); + + png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr, + (png_uint_32)(num_entries * (sizeof (png_byte)))); + + distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * + (sizeof (png_byte)))); + + memset(distance, 0xff, num_entries * (sizeof (png_byte))); + + for (i = 0; i < num_palette; i++) + { + int ir, ig, ib; + int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS)); + int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS)); + int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS)); + + for (ir = 0; ir < num_red; ir++) + { + /* int dr = abs(ir - r); */ + int dr = ((ir > r) ? ir - r : r - ir); + int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS + + PNG_QUANTIZE_GREEN_BITS)); + + for (ig = 0; ig < num_green; ig++) + { + /* int dg = abs(ig - g); */ + int dg = ((ig > g) ? ig - g : g - ig); + int dt = dr + dg; + int dm = ((dr > dg) ? dr : dg); + int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS); + + for (ib = 0; ib < num_blue; ib++) + { + int d_index = index_g | ib; + /* int db = abs(ib - b); */ + int db = ((ib > b) ? ib - b : b - ib); + int dmax = ((dm > db) ? dm : db); + int d = dmax + dt + db; + + if (d < (int)distance[d_index]) + { + distance[d_index] = (png_byte)d; + png_ptr->palette_lookup[d_index] = (png_byte)i; + } + } + } + } + } + + png_free(png_ptr, distance); + } +} +#endif /* READ_QUANTIZE */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +void PNGFAPI +png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma, + png_fixed_point file_gamma) +{ + png_debug(1, "in png_set_gamma_fixed"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + /* New in libpng-1.5.4 - reserve particular negative values as flags. */ + scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/); + file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/); + + /* Checking the gamma values for being >0 was added in 1.5.4 along with the + * premultiplied alpha support; this actually hides an undocumented feature + * of the previous implementation which allowed gamma processing to be + * disabled in background handling. There is no evidence (so far) that this + * was being used; however, png_set_background itself accepted and must still + * accept '0' for the gamma value it takes, because it isn't always used. + * + * Since this is an API change (albeit a very minor one that removes an + * undocumented API feature) the following checks were only enabled in + * libpng-1.6.0. + */ + if (file_gamma <= 0) + png_error(png_ptr, "invalid file gamma in png_set_gamma"); + + if (scrn_gamma <= 0) + png_error(png_ptr, "invalid screen gamma in png_set_gamma"); + + /* Set the gamma values unconditionally - this overrides the value in the PNG + * file if a gAMA chunk was present. png_set_alpha_mode provides a + * different, easier, way to default the file gamma. + */ + png_ptr->colorspace.gamma = file_gamma; + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + png_ptr->screen_gamma = scrn_gamma; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma) +{ + png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma), + convert_gamma_value(png_ptr, file_gamma)); +} +# endif /* FLOATING_POINT */ +#endif /* READ_GAMMA */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expand paletted images to RGB, expand grayscale images of + * less than 8-bit depth to 8-bit depth, and expand tRNS chunks + * to alpha channels. + */ +void PNGAPI +png_set_expand(png_structrp png_ptr) +{ + png_debug(1, "in png_set_expand"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); +} + +/* GRR 19990627: the following three functions currently are identical + * to png_set_expand(). However, it is entirely reasonable that someone + * might wish to expand an indexed image to RGB but *not* expand a single, + * fully transparent palette entry to a full alpha channel--perhaps instead + * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace + * the transparent color with a particular RGB value, or drop tRNS entirely. + * IOW, a future version of the library may make the transformations flag + * a bit more fine-grained, with separate bits for each of these three + * functions. + * + * More to the point, these functions make it obvious what libpng will be + * doing, whereas "expand" can (and does) mean any number of things. + * + * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified + * to expand only the sample depth but not to expand the tRNS to alpha + * and its name was changed to png_set_expand_gray_1_2_4_to_8(). + */ + +/* Expand paletted images to RGB. */ +void PNGAPI +png_set_palette_to_rgb(png_structrp png_ptr) +{ + png_debug(1, "in png_set_palette_to_rgb"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); +} + +/* Expand grayscale images of less than 8-bit depth to 8 bits. */ +void PNGAPI +png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr) +{ + png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= PNG_EXPAND; +} + +/* Expand tRNS chunks to alpha channels. */ +void PNGAPI +png_set_tRNS_to_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_tRNS_to_alpha"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); +} +#endif /* READ_EXPAND */ + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise + * it may not work correctly.) + */ +void PNGAPI +png_set_expand_16(png_structrp png_ptr) +{ + png_debug(1, "in png_set_expand_16"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS); +} +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +void PNGAPI +png_set_gray_to_rgb(png_structrp png_ptr) +{ + png_debug(1, "in png_set_gray_to_rgb"); + + if (png_rtran_ok(png_ptr, 0) == 0) + return; + + /* Because rgb must be 8 bits or more: */ + png_set_expand_gray_1_2_4_to_8(png_ptr); + png_ptr->transformations |= PNG_GRAY_TO_RGB; +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +void PNGFAPI +png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action, + png_fixed_point red, png_fixed_point green) +{ + png_debug(1, "in png_set_rgb_to_gray"); + + /* Need the IHDR here because of the check on color_type below. */ + /* TODO: fix this */ + if (png_rtran_ok(png_ptr, 1) == 0) + return; + + switch (error_action) + { + case PNG_ERROR_ACTION_NONE: + png_ptr->transformations |= PNG_RGB_TO_GRAY; + break; + + case PNG_ERROR_ACTION_WARN: + png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; + break; + + case PNG_ERROR_ACTION_ERROR: + png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; + break; + + default: + png_error(png_ptr, "invalid error action to rgb_to_gray"); + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#ifdef PNG_READ_EXPAND_SUPPORTED + png_ptr->transformations |= PNG_EXPAND; +#else + { + /* Make this an error in 1.6 because otherwise the application may assume + * that it just worked and get a memory overwrite. + */ + png_error(png_ptr, + "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED"); + + /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */ + } +#endif + { + if (red >= 0 && green >= 0 && red + green <= PNG_FP_1) + { + png_uint_16 red_int, green_int; + + /* NOTE: this calculation does not round, but this behavior is retained + * for consistency; the inaccuracy is very small. The code here always + * overwrites the coefficients, regardless of whether they have been + * defaulted or set already. + */ + red_int = (png_uint_16)(((png_uint_32)red*32768)/100000); + green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); + + png_ptr->rgb_to_gray_red_coeff = red_int; + png_ptr->rgb_to_gray_green_coeff = green_int; + png_ptr->rgb_to_gray_coefficients_set = 1; + } + + else + { + if (red >= 0 && green >= 0) + png_app_warning(png_ptr, + "ignoring out of range rgb_to_gray coefficients"); + + /* Use the defaults, from the cHRM chunk if set, else the historical + * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See + * png_do_rgb_to_gray for more discussion of the values. In this case + * the coefficients are not marked as 'set' and are not overwritten if + * something has already provided a default. + */ + if (png_ptr->rgb_to_gray_red_coeff == 0 && + png_ptr->rgb_to_gray_green_coeff == 0) + { + png_ptr->rgb_to_gray_red_coeff = 6968; + png_ptr->rgb_to_gray_green_coeff = 23434; + /* png_ptr->rgb_to_gray_blue_coeff = 2366; */ + } + } + } +} + +#ifdef PNG_FLOATING_POINT_SUPPORTED +/* Convert a RGB image to a grayscale of the same width. This allows us, + * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. + */ + +void PNGAPI +png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red, + double green) +{ + png_set_rgb_to_gray_fixed(png_ptr, error_action, + png_fixed(png_ptr, red, "rgb to gray red coefficient"), + png_fixed(png_ptr, green, "rgb to gray green coefficient")); +} +#endif /* FLOATING POINT */ + +#endif /* RGB_TO_GRAY */ + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +void PNGAPI +png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr + read_user_transform_fn) +{ + png_debug(1, "in png_set_read_user_transform_fn"); + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->read_user_transform_fn = read_user_transform_fn; +#endif +} +#endif + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +#ifdef PNG_READ_GAMMA_SUPPORTED +/* In the case of gamma transformations only do transformations on images where + * the [file] gamma and screen_gamma are not close reciprocals, otherwise it + * slows things down slightly, and also needlessly introduces small errors. + */ +static int /* PRIVATE */ +png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma) +{ + /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma + * correction as a difference of the overall transform from 1.0 + * + * We want to compare the threshold with s*f - 1, if we get + * overflow here it is because of wacky gamma values so we + * turn on processing anyway. + */ + png_fixed_point gtest; + return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) || + png_gamma_significant(gtest); +} +#endif + +/* Initialize everything needed for the read. This includes modifying + * the palette. + */ + +/* For the moment 'png_init_palette_transformations' and + * 'png_init_rgb_transformations' only do some flag canceling optimizations. + * The intent is that these two routines should have palette or rgb operations + * extracted from 'png_init_read_transformations'. + */ +static void /* PRIVATE */ +png_init_palette_transformations(png_structrp png_ptr) +{ + /* Called to handle the (input) palette case. In png_do_read_transformations + * the first step is to expand the palette if requested, so this code must + * take care to only make changes that are invariant with respect to the + * palette expansion, or only do them if there is no expansion. + * + * STRIP_ALPHA has already been handled in the caller (by setting num_trans + * to 0.) + */ + int input_has_alpha = 0; + int input_has_transparency = 0; + + if (png_ptr->num_trans > 0) + { + int i; + + /* Ignore if all the entries are opaque (unlikely!) */ + for (i=0; i<png_ptr->num_trans; ++i) + { + if (png_ptr->trans_alpha[i] == 255) + continue; + else if (png_ptr->trans_alpha[i] == 0) + input_has_transparency = 1; + else + { + input_has_transparency = 1; + input_has_alpha = 1; + break; + } + } + } + + /* If no alpha we can optimize. */ + if (input_has_alpha == 0) + { + /* Any alpha means background and associative alpha processing is + * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA + * and ENCODE_ALPHA are irrelevant. + */ + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + if (input_has_transparency == 0) + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); + } + +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* png_set_background handling - deals with the complexity of whether the + * background color is in the file format or the screen format in the case + * where an 'expand' will happen. + */ + + /* The following code cannot be entered in the alpha pre-multiplication case + * because PNG_BACKGROUND_EXPAND is cancelled below. + */ + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && + (png_ptr->transformations & PNG_EXPAND) != 0) + { + { + png_ptr->background.red = + png_ptr->palette[png_ptr->background.index].red; + png_ptr->background.green = + png_ptr->palette[png_ptr->background.index].green; + png_ptr->background.blue = + png_ptr->palette[png_ptr->background.index].blue; + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) + { + if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) + { + /* Invert the alpha channel (in tRNS) unless the pixels are + * going to be expanded, in which case leave it for later + */ + int i, istop = png_ptr->num_trans; + + for (i=0; i<istop; i++) + png_ptr->trans_alpha[i] = (png_byte)(255 - + png_ptr->trans_alpha[i]); + } + } +#endif /* READ_INVERT_ALPHA */ + } + } /* background expand and (therefore) no alpha association. */ +#endif /* READ_EXPAND && READ_BACKGROUND */ +} + +static void /* PRIVATE */ +png_init_rgb_transformations(png_structrp png_ptr) +{ + /* Added to libpng-1.5.4: check the color type to determine whether there + * is any alpha or transparency in the image and simply cancel the + * background and alpha mode stuff if there isn't. + */ + int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0; + int input_has_transparency = png_ptr->num_trans > 0; + + /* If no alpha we can optimize. */ + if (input_has_alpha == 0) + { + /* Any alpha means background and associative alpha processing is + * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA + * and ENCODE_ALPHA are irrelevant. + */ +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; +# endif + + if (input_has_transparency == 0) + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); + } + +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* png_set_background handling - deals with the complexity of whether the + * background color is in the file format or the screen format in the case + * where an 'expand' will happen. + */ + + /* The following code cannot be entered in the alpha pre-multiplication case + * because PNG_BACKGROUND_EXPAND is cancelled below. + */ + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && + (png_ptr->transformations & PNG_EXPAND) != 0 && + (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + /* i.e., GRAY or GRAY_ALPHA */ + { + { + /* Expand background and tRNS chunks */ + int gray = png_ptr->background.gray; + int trans_gray = png_ptr->trans_color.gray; + + switch (png_ptr->bit_depth) + { + case 1: + gray *= 0xff; + trans_gray *= 0xff; + break; + + case 2: + gray *= 0x55; + trans_gray *= 0x55; + break; + + case 4: + gray *= 0x11; + trans_gray *= 0x11; + break; + + default: + + case 8: + /* FALL THROUGH (Already 8 bits) */ + + case 16: + /* Already a full 16 bits */ + break; + } + + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = (png_uint_16)gray; + + if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) + { + png_ptr->trans_color.red = png_ptr->trans_color.green = + png_ptr->trans_color.blue = (png_uint_16)trans_gray; + } + } + } /* background expand and (therefore) no alpha association. */ +#endif /* READ_EXPAND && READ_BACKGROUND */ +} + +void /* PRIVATE */ +png_init_read_transformations(png_structrp png_ptr) +{ + png_debug(1, "in png_init_read_transformations"); + + /* This internal function is called from png_read_start_row in pngrutil.c + * and it is called before the 'rowbytes' calculation is done, so the code + * in here can change or update the transformations flags. + * + * First do updates that do not depend on the details of the PNG image data + * being processed. + */ + +#ifdef PNG_READ_GAMMA_SUPPORTED + /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds + * png_set_alpha_mode and this is another source for a default file gamma so + * the test needs to be performed later - here. In addition prior to 1.5.4 + * the tests were repeated for the PALETTE color type here - this is no + * longer necessary (and doesn't seem to have been necessary before.) + */ + { + /* The following temporary indicates if overall gamma correction is + * required. + */ + int gamma_correction = 0; + + if (png_ptr->colorspace.gamma != 0) /* has been set */ + { + if (png_ptr->screen_gamma != 0) /* screen set too */ + gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma, + png_ptr->screen_gamma); + + else + /* Assume the output matches the input; a long time default behavior + * of libpng, although the standard has nothing to say about this. + */ + png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma); + } + + else if (png_ptr->screen_gamma != 0) + /* The converse - assume the file matches the screen, note that this + * perhaps undesireable default can (from 1.5.4) be changed by calling + * png_set_alpha_mode (even if the alpha handling mode isn't required + * or isn't changed from the default.) + */ + png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma); + + else /* neither are set */ + /* Just in case the following prevents any processing - file and screen + * are both assumed to be linear and there is no way to introduce a + * third gamma value other than png_set_background with 'UNIQUE', and, + * prior to 1.5.4 + */ + png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1; + + /* We have a gamma value now. */ + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; + + /* Now turn the gamma transformation on or off as appropriate. Notice + * that PNG_GAMMA just refers to the file->screen correction. Alpha + * composition may independently cause gamma correction because it needs + * linear data (e.g. if the file has a gAMA chunk but the screen gamma + * hasn't been specified.) In any case this flag may get turned off in + * the code immediately below if the transform can be handled outside the + * row loop. + */ + if (gamma_correction != 0) + png_ptr->transformations |= PNG_GAMMA; + + else + png_ptr->transformations &= ~PNG_GAMMA; + } +#endif + + /* Certain transformations have the effect of preventing other + * transformations that happen afterward in png_do_read_transformations; + * resolve the interdependencies here. From the code of + * png_do_read_transformations the order is: + * + * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) + * 2) PNG_STRIP_ALPHA (if no compose) + * 3) PNG_RGB_TO_GRAY + * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY + * 5) PNG_COMPOSE + * 6) PNG_GAMMA + * 7) PNG_STRIP_ALPHA (if compose) + * 8) PNG_ENCODE_ALPHA + * 9) PNG_SCALE_16_TO_8 + * 10) PNG_16_TO_8 + * 11) PNG_QUANTIZE (converts to palette) + * 12) PNG_EXPAND_16 + * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY + * 14) PNG_INVERT_MONO + * 15) PNG_INVERT_ALPHA + * 16) PNG_SHIFT + * 17) PNG_PACK + * 18) PNG_BGR + * 19) PNG_PACKSWAP + * 20) PNG_FILLER (includes PNG_ADD_ALPHA) + * 21) PNG_SWAP_ALPHA + * 22) PNG_SWAP_BYTES + * 23) PNG_USER_TRANSFORM [must be last] + */ +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && + (png_ptr->transformations & PNG_COMPOSE) == 0) + { + /* Stripping the alpha channel happens immediately after the 'expand' + * transformations, before all other transformation, so it cancels out + * the alpha handling. It has the side effect negating the effect of + * PNG_EXPAND_tRNS too: + */ + png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | + PNG_EXPAND_tRNS); + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + + /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen + * so transparency information would remain just so long as it wasn't + * expanded. This produces unexpected API changes if the set of things + * that do PNG_EXPAND_tRNS changes (perfectly possible given the + * documentation - which says ask for what you want, accept what you + * get.) This makes the behavior consistent from 1.5.4: + */ + png_ptr->num_trans = 0; + } +#endif /* STRIP_ALPHA supported, no COMPOSE */ + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA + * settings will have no effect. + */ + if (png_gamma_significant(png_ptr->screen_gamma) == 0) + { + png_ptr->transformations &= ~PNG_ENCODE_ALPHA; + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; + } +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Make sure the coefficients for the rgb to gray conversion are set + * appropriately. + */ + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + png_colorspace_set_rgb_coefficients(png_ptr); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + /* Detect gray background and attempt to enable optimization for + * gray --> RGB case. + * + * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or + * RGB_ALPHA (in which case need_expand is superfluous anyway), the + * background color might actually be gray yet not be flagged as such. + * This is not a problem for the current code, which uses + * PNG_BACKGROUND_IS_GRAY only to decide when to do the + * png_do_gray_to_rgb() transformation. + * + * TODO: this code needs to be revised to avoid the complexity and + * interdependencies. The color type of the background should be recorded in + * png_set_background, along with the bit depth, then the code has a record + * of exactly what color space the background is currently in. + */ + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0) + { + /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if + * the file was grayscale the background value is gray. + */ + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + } + + else if ((png_ptr->transformations & PNG_COMPOSE) != 0) + { + /* PNG_COMPOSE: png_set_background was called with need_expand false, + * so the color is in the color space of the output or png_set_alpha_mode + * was called and the color is black. Ignore RGB_TO_GRAY because that + * happens before GRAY_TO_RGB. + */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) + { + if (png_ptr->background.red == png_ptr->background.green && + png_ptr->background.red == png_ptr->background.blue) + { + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + png_ptr->background.gray = png_ptr->background.red; + } + } + } +#endif /* READ_EXPAND && READ_BACKGROUND */ +#endif /* READ_GRAY_TO_RGB */ + + /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations + * can be performed directly on the palette, and some (such as rgb to gray) + * can be optimized inside the palette. This is particularly true of the + * composite (background and alpha) stuff, which can be pretty much all done + * in the palette even if the result is expanded to RGB or gray afterward. + * + * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and + * earlier and the palette stuff is actually handled on the first row. This + * leads to the reported bug that the palette returned by png_get_PLTE is not + * updated. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_init_palette_transformations(png_ptr); + + else + png_init_rgb_transformations(png_ptr); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + defined(PNG_READ_EXPAND_16_SUPPORTED) + if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && + (png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && + png_ptr->bit_depth != 16) + { + /* TODO: fix this. Because the expand_16 operation is after the compose + * handling the background color must be 8, not 16, bits deep, but the + * application will supply a 16-bit value so reduce it here. + * + * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at + * present, so that case is ok (until do_expand_16 is moved.) + * + * NOTE: this discards the low 16 bits of the user supplied background + * color, but until expand_16 works properly there is no choice! + */ +# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x)) + CHOP(png_ptr->background.red); + CHOP(png_ptr->background.green); + CHOP(png_ptr->background.blue); + CHOP(png_ptr->background.gray); +# undef CHOP + } +#endif /* READ_BACKGROUND && READ_EXPAND_16 */ + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ + defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) + if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 && + (png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && + png_ptr->bit_depth == 16) + { + /* On the other hand, if a 16-bit file is to be reduced to 8-bits per + * component this will also happen after PNG_COMPOSE and so the background + * color must be pre-expanded here. + * + * TODO: fix this too. + */ + png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); + png_ptr->background.green = + (png_uint_16)(png_ptr->background.green * 257); + png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); + png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); + } +#endif + + /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the + * background support (see the comments in scripts/pnglibconf.dfa), this + * allows pre-multiplication of the alpha channel to be implemented as + * compositing on black. This is probably sub-optimal and has been done in + * 1.5.4 betas simply to enable external critique and testing (i.e. to + * implement the new API quickly, without lots of internal changes.) + */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +# ifdef PNG_READ_BACKGROUND_SUPPORTED + /* Includes ALPHA_MODE */ + png_ptr->background_1 = png_ptr->background; +# endif + + /* This needs to change - in the palette image case a whole set of tables are + * built when it would be quicker to just calculate the correct value for + * each palette entry directly. Also, the test is too tricky - why check + * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that + * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the + * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction + * the gamma tables will not be built even if composition is required on a + * gamma encoded value. + * + * In 1.5.4 this is addressed below by an additional check on the individual + * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the + * tables. + */ + if ((png_ptr->transformations & PNG_GAMMA) != 0 || + ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 && + (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || + png_gamma_significant(png_ptr->screen_gamma) != 0)) || + ((png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || + png_gamma_significant(png_ptr->screen_gamma) != 0 +# ifdef PNG_READ_BACKGROUND_SUPPORTED + || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE && + png_gamma_significant(png_ptr->background_gamma) != 0) +# endif + )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && + png_gamma_significant(png_ptr->screen_gamma) != 0)) + { + png_build_gamma_table(png_ptr, png_ptr->bit_depth); + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + { + /* Issue a warning about this combination: because RGB_TO_GRAY is + * optimized to do the gamma transform if present yet do_background has + * to do the same thing if both options are set a + * double-gamma-correction happens. This is true in all versions of + * libpng to date. + */ + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + png_warning(png_ptr, + "libpng does not support gamma+background+rgb_to_gray"); + + if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0) + { + /* We don't get to here unless there is a tRNS chunk with non-opaque + * entries - see the checking code at the start of this function. + */ + png_color back, back_1; + png_colorp palette = png_ptr->palette; + int num_palette = png_ptr->num_palette; + int i; + if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) + { + + back.red = png_ptr->gamma_table[png_ptr->background.red]; + back.green = png_ptr->gamma_table[png_ptr->background.green]; + back.blue = png_ptr->gamma_table[png_ptr->background.blue]; + + back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; + back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; + back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; + } + else + { + png_fixed_point g, gs; + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = (png_ptr->screen_gamma); + gs = PNG_FP_1; + break; + + case PNG_BACKGROUND_GAMMA_FILE: + g = png_reciprocal(png_ptr->colorspace.gamma); + gs = png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma); + break; + + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = png_reciprocal(png_ptr->background_gamma); + gs = png_reciprocal2(png_ptr->background_gamma, + png_ptr->screen_gamma); + break; + default: + g = PNG_FP_1; /* back_1 */ + gs = PNG_FP_1; /* back */ + break; + } + + if (png_gamma_significant(gs) != 0) + { + back.red = png_gamma_8bit_correct(png_ptr->background.red, + gs); + back.green = png_gamma_8bit_correct(png_ptr->background.green, + gs); + back.blue = png_gamma_8bit_correct(png_ptr->background.blue, + gs); + } + + else + { + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + } + + if (png_gamma_significant(g) != 0) + { + back_1.red = png_gamma_8bit_correct(png_ptr->background.red, + g); + back_1.green = png_gamma_8bit_correct( + png_ptr->background.green, g); + back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, + g); + } + + else + { + back_1.red = (png_byte)png_ptr->background.red; + back_1.green = (png_byte)png_ptr->background.green; + back_1.blue = (png_byte)png_ptr->background.blue; + } + } + + for (i = 0; i < num_palette; i++) + { + if (i < (int)png_ptr->num_trans && + png_ptr->trans_alpha[i] != 0xff) + { + if (png_ptr->trans_alpha[i] == 0) + { + palette[i] = back; + } + else /* if (png_ptr->trans_alpha[i] != 0xff) */ + { + png_byte v, w; + + v = png_ptr->gamma_to_1[palette[i].red]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); + palette[i].red = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].green]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); + palette[i].green = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].blue]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); + palette[i].blue = png_ptr->gamma_from_1[w]; + } + } + else + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } + + /* Prevent the transformations being done again. + * + * NOTE: this is highly dubious; it removes the transformations in + * place. This seems inconsistent with the general treatment of the + * transformations elsewhere. + */ + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); + } /* color_type == PNG_COLOR_TYPE_PALETTE */ + + /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ + else /* color_type != PNG_COLOR_TYPE_PALETTE */ + { + int gs_sig, g_sig; + png_fixed_point g = PNG_FP_1; /* Correction to linear */ + png_fixed_point gs = PNG_FP_1; /* Correction to screen */ + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = png_ptr->screen_gamma; + /* gs = PNG_FP_1; */ + break; + + case PNG_BACKGROUND_GAMMA_FILE: + g = png_reciprocal(png_ptr->colorspace.gamma); + gs = png_reciprocal2(png_ptr->colorspace.gamma, + png_ptr->screen_gamma); + break; + + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = png_reciprocal(png_ptr->background_gamma); + gs = png_reciprocal2(png_ptr->background_gamma, + png_ptr->screen_gamma); + break; + + default: + png_error(png_ptr, "invalid background gamma type"); + } + + g_sig = png_gamma_significant(g); + gs_sig = png_gamma_significant(gs); + + if (g_sig != 0) + png_ptr->background_1.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, g); + + if (gs_sig != 0) + png_ptr->background.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, gs); + + if ((png_ptr->background.red != png_ptr->background.green) || + (png_ptr->background.red != png_ptr->background.blue) || + (png_ptr->background.red != png_ptr->background.gray)) + { + /* RGB or RGBA with color background */ + if (g_sig != 0) + { + png_ptr->background_1.red = png_gamma_correct(png_ptr, + png_ptr->background.red, g); + + png_ptr->background_1.green = png_gamma_correct(png_ptr, + png_ptr->background.green, g); + + png_ptr->background_1.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, g); + } + + if (gs_sig != 0) + { + png_ptr->background.red = png_gamma_correct(png_ptr, + png_ptr->background.red, gs); + + png_ptr->background.green = png_gamma_correct(png_ptr, + png_ptr->background.green, gs); + + png_ptr->background.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, gs); + } + } + + else + { + /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ + png_ptr->background_1.red = png_ptr->background_1.green + = png_ptr->background_1.blue = png_ptr->background_1.gray; + + png_ptr->background.red = png_ptr->background.green + = png_ptr->background.blue = png_ptr->background.gray; + } + + /* The background is now in screen gamma: */ + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; + } /* color_type != PNG_COLOR_TYPE_PALETTE */ + }/* png_ptr->transformations & PNG_BACKGROUND */ + + else + /* Transformation does not include PNG_BACKGROUND */ +#endif /* READ_BACKGROUND */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ + && ((png_ptr->transformations & PNG_EXPAND) == 0 || + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) +#endif + ) + { + png_colorp palette = png_ptr->palette; + int num_palette = png_ptr->num_palette; + int i; + + /* NOTE: there are other transformations that should probably be in + * here too. + */ + for (i = 0; i < num_palette; i++) + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + + /* Done the gamma correction. */ + png_ptr->transformations &= ~PNG_GAMMA; + } /* color_type == PALETTE && !PNG_BACKGROUND transformation */ + } +#ifdef PNG_READ_BACKGROUND_SUPPORTED + else +#endif +#endif /* READ_GAMMA */ + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + /* No GAMMA transformation (see the hanging else 4 lines above) */ + if ((png_ptr->transformations & PNG_COMPOSE) != 0 && + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) + { + int i; + int istop = (int)png_ptr->num_trans; + png_color back; + png_colorp palette = png_ptr->palette; + + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + + for (i = 0; i < istop; i++) + { + if (png_ptr->trans_alpha[i] == 0) + { + palette[i] = back; + } + + else if (png_ptr->trans_alpha[i] != 0xff) + { + /* The png_composite() macro is defined in png.h */ + png_composite(palette[i].red, palette[i].red, + png_ptr->trans_alpha[i], back.red); + + png_composite(palette[i].green, palette[i].green, + png_ptr->trans_alpha[i], back.green); + + png_composite(palette[i].blue, palette[i].blue, + png_ptr->trans_alpha[i], back.blue); + } + } + + png_ptr->transformations &= ~PNG_COMPOSE; + } +#endif /* READ_BACKGROUND */ + +#ifdef PNG_READ_SHIFT_SUPPORTED + if ((png_ptr->transformations & PNG_SHIFT) != 0 && + (png_ptr->transformations & PNG_EXPAND) == 0 && + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) + { + int i; + int istop = png_ptr->num_palette; + int shift = 8 - png_ptr->sig_bit.red; + + png_ptr->transformations &= ~PNG_SHIFT; + + /* significant bits can be in the range 1 to 7 for a meaninful result, if + * the number of significant bits is 0 then no shift is done (this is an + * error condition which is silently ignored.) + */ + if (shift > 0 && shift < 8) + for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].red; + + component >>= shift; + png_ptr->palette[i].red = (png_byte)component; + } + + shift = 8 - png_ptr->sig_bit.green; + if (shift > 0 && shift < 8) + for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].green; + + component >>= shift; + png_ptr->palette[i].green = (png_byte)component; + } + + shift = 8 - png_ptr->sig_bit.blue; + if (shift > 0 && shift < 8) + for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].blue; + + component >>= shift; + png_ptr->palette[i].blue = (png_byte)component; + } + } +#endif /* READ_SHIFT */ +} + +/* Modify the info structure to reflect the transformations. The + * info should be updated so a PNG file could be written with it, + * assuming the transformations result in valid PNG data. + */ +void /* PRIVATE */ +png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr) +{ + png_debug(1, "in png_read_transform_info"); + +#ifdef PNG_READ_EXPAND_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + /* This check must match what actually happens in + * png_do_expand_palette; if it ever checks the tRNS chunk to see if + * it is all opaque we must do the same (at present it does not.) + */ + if (png_ptr->num_trans > 0) + info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + + else + info_ptr->color_type = PNG_COLOR_TYPE_RGB; + + info_ptr->bit_depth = 8; + info_ptr->num_trans = 0; + + if (png_ptr->palette == NULL) + png_error (png_ptr, "Palette is NULL in indexed image"); + } + else + { + if (png_ptr->num_trans != 0) + { + if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0) + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; + } + if (info_ptr->bit_depth < 8) + info_ptr->bit_depth = 8; + + info_ptr->num_trans = 0; + } + } +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + /* The following is almost certainly wrong unless the background value is in + * the screen space! + */ + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + info_ptr->background = png_ptr->background; +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4), + * however it seems that the code in png_init_read_transformations, which has + * been called before this from png_read_update_info->png_read_start_row + * sometimes does the gamma transform and cancels the flag. + * + * TODO: this looks wrong; the info_ptr should end up with a gamma equal to + * the screen_gamma value. The following probably results in weirdness if + * the info_ptr is used by the app after the rows have been read. + */ + info_ptr->colorspace.gamma = png_ptr->colorspace.gamma; +#endif + + if (info_ptr->bit_depth == 16) + { +# ifdef PNG_READ_16BIT_SUPPORTED +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) + info_ptr->bit_depth = 8; +# endif + +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + if ((png_ptr->transformations & PNG_16_TO_8) != 0) + info_ptr->bit_depth = 8; +# endif + +# else + /* No 16-bit support: force chopping 16-bit input down to 8, in this case + * the app program can chose if both APIs are available by setting the + * correct scaling to use. + */ +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + /* For compatibility with previous versions use the strip method by + * default. This code works because if PNG_SCALE_16_TO_8 is already + * set the code below will do that in preference to the chop. + */ + png_ptr->transformations |= PNG_16_TO_8; + info_ptr->bit_depth = 8; +# else + +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + png_ptr->transformations |= PNG_SCALE_16_TO_8; + info_ptr->bit_depth = 8; +# else + + CONFIGURATION ERROR: you must enable at least one 16 to 8 method +# endif +# endif +#endif /* !READ_16BIT */ + } + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) + info_ptr->color_type = (png_byte)(info_ptr->color_type | + PNG_COLOR_MASK_COLOR); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_COLOR); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + if ((png_ptr->transformations & PNG_QUANTIZE) != 0) + { + if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || + (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && + png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8) + { + info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; + } + } +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && + info_ptr->bit_depth == 8 && + info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + info_ptr->bit_depth = 16; + } +#endif + +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0 && + (info_ptr->bit_depth < 8)) + info_ptr->bit_depth = 8; +#endif + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + + else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + info_ptr->channels = 3; + + else + info_ptr->channels = 1; + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0) + { + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_ALPHA); + info_ptr->num_trans = 0; + } +#endif + + if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + info_ptr->channels++; + +#ifdef PNG_READ_FILLER_SUPPORTED + /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ + if ((png_ptr->transformations & PNG_FILLER) != 0 && + (info_ptr->color_type == PNG_COLOR_TYPE_RGB || + info_ptr->color_type == PNG_COLOR_TYPE_GRAY)) + { + info_ptr->channels++; + /* If adding a true alpha channel not just filler */ + if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0) + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; + } +#endif + +#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ +defined(PNG_READ_USER_TRANSFORM_SUPPORTED) + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + { + if (png_ptr->user_transform_depth != 0) + info_ptr->bit_depth = png_ptr->user_transform_depth; + + if (png_ptr->user_transform_channels != 0) + info_ptr->channels = png_ptr->user_transform_channels; + } +#endif + + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * + info_ptr->bit_depth); + + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); + + /* Adding in 1.5.4: cache the above value in png_struct so that we can later + * check in png_rowbytes that the user buffer won't get overwritten. Note + * that the field is not always set - if png_read_update_info isn't called + * the application has to either not do any transforms or get the calculation + * right itself. + */ + png_ptr->info_rowbytes = info_ptr->rowbytes; + +#ifndef PNG_READ_EXPAND_SUPPORTED + if (png_ptr != NULL) + return; +#endif +} + +#ifdef PNG_READ_PACK_SUPPORTED +/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, + * without changing the actual values. Thus, if you had a row with + * a bit depth of 1, you would end up with bytes that only contained + * the numbers 0 or 1. If you would rather they contain 0 and 255, use + * png_do_shift() after this. + */ +static void +png_do_unpack(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_unpack"); + + if (row_info->bit_depth < 8) + { + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + switch (row_info->bit_depth) + { + case 1: + { + png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); + png_bytep dp = row + (png_size_t)row_width - 1; + png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x01); + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + + png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); + png_bytep dp = row + (png_size_t)row_width - 1; + png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x03); + + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); + png_bytep dp = row + (png_size_t)row_width - 1; + png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x0f); + + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift = 4; + + dp--; + } + break; + } + + default: + break; + } + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED +/* Reverse the effects of png_do_shift. This routine merely shifts the + * pixels back to their significant bits values. Thus, if you have + * a row of bit depth 8, but only 5 are significant, this will shift + * the values back to 0 through 31. + */ +static void +png_do_unshift(png_row_infop row_info, png_bytep row, + png_const_color_8p sig_bits) +{ + int color_type; + + png_debug(1, "in png_do_unshift"); + + /* The palette case has already been handled in the _init routine. */ + color_type = row_info->color_type; + + if (color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift[4]; + int channels = 0; + int bit_depth = row_info->bit_depth; + + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + { + shift[channels++] = bit_depth - sig_bits->red; + shift[channels++] = bit_depth - sig_bits->green; + shift[channels++] = bit_depth - sig_bits->blue; + } + + else + { + shift[channels++] = bit_depth - sig_bits->gray; + } + + if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + shift[channels++] = bit_depth - sig_bits->alpha; + } + + { + int c, have_shift; + + for (c = have_shift = 0; c < channels; ++c) + { + /* A shift of more than the bit depth is an error condition but it + * gets ignored here. + */ + if (shift[c] <= 0 || shift[c] >= bit_depth) + shift[c] = 0; + + else + have_shift = 1; + } + + if (have_shift == 0) + return; + } + + switch (bit_depth) + { + default: + /* Must be 1bpp gray: should not be here! */ + /* NOTREACHED */ + break; + + case 2: + /* Must be 2bpp gray */ + /* assert(channels == 1 && shift[0] == 1) */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + + while (bp < bp_end) + { + int b = (*bp >> 1) & 0x55; + *bp++ = (png_byte)b; + } + break; + } + + case 4: + /* Must be 4bpp gray */ + /* assert(channels == 1) */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + int gray_shift = shift[0]; + int mask = 0xf >> gray_shift; + + mask |= mask << 4; + + while (bp < bp_end) + { + int b = (*bp >> gray_shift) & mask; + *bp++ = (png_byte)b; + } + break; + } + + case 8: + /* Single byte components, G, GA, RGB, RGBA */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; + + while (bp < bp_end) + { + int b = *bp >> shift[channel]; + if (++channel >= channels) + channel = 0; + *bp++ = (png_byte)b; + } + break; + } + +#ifdef PNG_READ_16BIT_SUPPORTED + case 16: + /* Double byte components, G, GA, RGB, RGBA */ + { + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; + + while (bp < bp_end) + { + int value = (bp[0] << 8) + bp[1]; + + value >>= shift[channel]; + if (++channel >= channels) + channel = 0; + *bp++ = (png_byte)(value >> 8); + *bp++ = (png_byte)value; + } + break; + } +#endif + } + } +} +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED +/* Scale rows of bit depth 16 down to 8 accurately */ +static void +png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_scale_16_to_8"); + + if (row_info->bit_depth == 16) + { + png_bytep sp = row; /* source */ + png_bytep dp = row; /* destination */ + png_bytep ep = sp + row_info->rowbytes; /* end+1 */ + + while (sp < ep) + { + /* The input is an array of 16-bit components, these must be scaled to + * 8 bits each. For a 16-bit value V the required value (from the PNG + * specification) is: + * + * (V * 255) / 65535 + * + * This reduces to round(V / 257), or floor((V + 128.5)/257) + * + * Represent V as the two byte value vhi.vlo. Make a guess that the + * result is the top byte of V, vhi, then the correction to this value + * is: + * + * error = floor(((V-vhi.vhi) + 128.5) / 257) + * = floor(((vlo-vhi) + 128.5) / 257) + * + * This can be approximated using integer arithmetic (and a signed + * shift): + * + * error = (vlo-vhi+128) >> 8; + * + * The approximate differs from the exact answer only when (vlo-vhi) is + * 128; it then gives a correction of +1 when the exact correction is + * 0. This gives 128 errors. The exact answer (correct for all 16-bit + * input values) is: + * + * error = (vlo-vhi+128)*65535 >> 24; + * + * An alternative arithmetic calculation which also gives no errors is: + * + * (V * 255 + 32895) >> 16 + */ + + png_int_32 tmp = *sp++; /* must be signed! */ + tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24; + *dp++ = (png_byte)tmp; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED +static void +/* Simply discard the low byte. This was the default behavior prior + * to libpng-1.5.4. + */ +png_do_chop(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_chop"); + + if (row_info->bit_depth == 16) + { + png_bytep sp = row; /* source */ + png_bytep dp = row; /* destination */ + png_bytep ep = sp + row_info->rowbytes; /* end+1 */ + + while (sp < ep) + { + *dp++ = *sp; + sp += 2; /* skip low byte */ + } + + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED +static void +png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_read_swap_alpha"); + + { + png_uint_32 row_width = row_info->width; + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + /* This converts from RGBA to ARGB */ + if (row_info->bit_depth == 8) + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This converts from RRGGBBAA to AARRGGBB */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } +#endif + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + /* This converts from GA to AG */ + if (row_info->bit_depth == 8) + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This converts from GGAA to AAGG */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } +#endif + } + } +} +#endif + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED +static void +png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_uint_32 row_width; + png_debug(1, "in png_do_read_invert_alpha"); + + row_width = row_info->width; + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in RGBA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + +/* This does nothing: + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + We can replace it with: +*/ + sp-=3; + dp=sp; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This inverts the alpha channel in RRGGBBAA */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = (png_byte)(255 - *(--sp)); + +/* This does nothing: + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + We can replace it with: +*/ + sp-=6; + dp=sp; + } + } +#endif + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in GA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = *(--sp); + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in GGAA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = (png_byte)(255 - *(--sp)); +/* + *(--dp) = *(--sp); + *(--dp) = *(--sp); +*/ + sp-=2; + dp=sp; + } + } +#endif + } +} +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED +/* Add filler channel if we have RGB color */ +static void +png_do_read_filler(png_row_infop row_info, png_bytep row, + png_uint_32 filler, png_uint_32 flags) +{ + png_uint_32 i; + png_uint_32 row_width = row_info->width; + +#ifdef PNG_READ_16BIT_SUPPORTED + png_byte hi_filler = (png_byte)(filler>>8); +#endif + png_byte lo_filler = (png_byte)filler; + + png_debug(1, "in png_do_read_filler"); + + if ( + row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + if (row_info->bit_depth == 8) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from G to GX */ + png_bytep sp = row + (png_size_t)row_width; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + row_info->channels = 2; + row_info->pixel_depth = 16; + row_info->rowbytes = row_width * 2; + } + + else + { + /* This changes the data from G to XG */ + png_bytep sp = row + (png_size_t)row_width; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = lo_filler; + } + row_info->channels = 2; + row_info->pixel_depth = 16; + row_info->rowbytes = row_width * 2; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from GG to GGXX */ + png_bytep sp = row + (png_size_t)row_width * 2; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = hi_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + *(--dp) = hi_filler; + row_info->channels = 2; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + + else + { + /* This changes the data from GG to XXGG */ + png_bytep sp = row + (png_size_t)row_width * 2; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = lo_filler; + *(--dp) = hi_filler; + } + row_info->channels = 2; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + } +#endif + } /* COLOR_TYPE == GRAY */ + else if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + if (row_info->bit_depth == 8) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from RGB to RGBX */ + png_bytep sp = row + (png_size_t)row_width * 3; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + + else + { + /* This changes the data from RGB to XRGB */ + png_bytep sp = row + (png_size_t)row_width * 3; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = lo_filler; + } + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if ((flags & PNG_FLAG_FILLER_AFTER) != 0) + { + /* This changes the data from RRGGBB to RRGGBBXX */ + png_bytep sp = row + (png_size_t)row_width * 6; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = hi_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + *(--dp) = hi_filler; + row_info->channels = 4; + row_info->pixel_depth = 64; + row_info->rowbytes = row_width * 8; + } + + else + { + /* This changes the data from RRGGBB to XXRRGGBB */ + png_bytep sp = row + (png_size_t)row_width * 6; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = lo_filler; + *(--dp) = hi_filler; + } + + row_info->channels = 4; + row_info->pixel_depth = 64; + row_info->rowbytes = row_width * 8; + } + } +#endif + } /* COLOR_TYPE == RGB */ +} +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* Expand grayscale files to RGB, with or without alpha */ +static void +png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) +{ + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + png_debug(1, "in png_do_gray_to_rgb"); + + if (row_info->bit_depth >= 8 && + (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0) + { + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + if (row_info->bit_depth == 8) + { + /* This changes G to RGB */ + png_bytep sp = row + (png_size_t)row_width - 1; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *(sp--); + } + } + + else + { + /* This changes GG to RRGGBB */ + png_bytep sp = row + (png_size_t)row_width * 2 - 1; + png_bytep dp = sp + (png_size_t)row_width * 4; + for (i = 0; i < row_width; i++) + { + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *(sp--); + *(dp--) = *(sp--); + } + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This changes GA to RGBA */ + png_bytep sp = row + (png_size_t)row_width * 2 - 1; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *(sp--); + } + } + + else + { + /* This changes GGAA to RRGGBBAA */ + png_bytep sp = row + (png_size_t)row_width * 4 - 1; + png_bytep dp = sp + (png_size_t)row_width * 4; + for (i = 0; i < row_width; i++) + { + *(dp--) = *(sp--); + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *(sp--); + *(dp--) = *(sp--); + } + } + } + row_info->channels = (png_byte)(row_info->channels + 2); + row_info->color_type |= PNG_COLOR_MASK_COLOR; + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* Reduce RGB files to grayscale, with or without alpha + * using the equation given in Poynton's ColorFAQ of 1998-01-04 at + * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but + * versions dated 1998 through November 2002 have been archived at + * http://web.archive.org/web/20000816232553/http://www.inforamp.net/ + * ~poynton/notes/colour_and_gamma/ColorFAQ.txt ) + * Charles Poynton poynton at poynton.com + * + * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B + * + * which can be expressed with integers as + * + * Y = (6969 * R + 23434 * G + 2365 * B)/32768 + * + * Poynton's current link (as of January 2003 through July 2011): + * <http://www.poynton.com/notes/colour_and_gamma/> + * has changed the numbers slightly: + * + * Y = 0.2126*R + 0.7152*G + 0.0722*B + * + * which can be expressed with integers as + * + * Y = (6966 * R + 23436 * G + 2366 * B)/32768 + * + * Historically, however, libpng uses numbers derived from the ITU-R Rec 709 + * end point chromaticities and the D65 white point. Depending on the + * precision used for the D65 white point this produces a variety of different + * numbers, however if the four decimal place value used in ITU-R Rec 709 is + * used (0.3127,0.3290) the Y calculation would be: + * + * Y = (6968 * R + 23435 * G + 2366 * B)/32768 + * + * While this is correct the rounding results in an overflow for white, because + * the sum of the rounded coefficients is 32769, not 32768. Consequently + * libpng uses, instead, the closest non-overflowing approximation: + * + * Y = (6968 * R + 23434 * G + 2366 * B)/32768 + * + * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk + * (including an sRGB chunk) then the chromaticities are used to calculate the + * coefficients. See the chunk handling in pngrutil.c for more information. + * + * In all cases the calculation is to be done in a linear colorspace. If no + * gamma information is available to correct the encoding of the original RGB + * values this results in an implicit assumption that the original PNG RGB + * values were linear. + * + * Other integer coefficents can be used via png_set_rgb_to_gray(). Because + * the API takes just red and green coefficients the blue coefficient is + * calculated to make the sum 32768. This will result in different rounding + * to that used above. + */ +static int +png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row) + +{ + int rgb_error = 0; + + png_debug(1, "in png_do_rgb_to_gray"); + + if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 && + (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; + PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; + PNG_CONST png_uint_32 bc = 32768 - rc - gc; + PNG_CONST png_uint_32 row_width = row_info->width; + PNG_CONST int have_alpha = + (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; + + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + /* Notice that gamma to/from 1 are not necessarily inverses (if + * there is an overall gamma correction). Prior to 1.5.5 this code + * checked the linearized values for equality; this doesn't match + * the documentation, the original values must be checked. + */ + if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); + + if (red != green || red != blue) + { + red = png_ptr->gamma_to_1[red]; + green = png_ptr->gamma_to_1[green]; + blue = png_ptr->gamma_to_1[blue]; + + rgb_error |= 1; + *(dp++) = png_ptr->gamma_from_1[ + (rc*red + gc*green + bc*blue + 16384)>>15]; + } + + else + { + /* If there is no overall correction the table will not be + * set. + */ + if (png_ptr->gamma_table != NULL) + red = png_ptr->gamma_table[red]; + + *(dp++) = red; + } + + if (have_alpha != 0) + *(dp++) = *(sp++); + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); + + if (red != green || red != blue) + { + rgb_error |= 1; + /* NOTE: this is the historical approach which simply + * truncates the results. + */ + *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); + } + + else + *(dp++) = red; + + if (have_alpha != 0) + *(dp++) = *(sp++); + } + } + } + + else /* RGB bit_depth == 16 */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, w; + png_byte hi,lo; + + hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); + + if (red == green && red == blue) + { + if (png_ptr->gamma_16_table != NULL) + w = png_ptr->gamma_16_table[(red & 0xff) + >> png_ptr->gamma_shift][red >> 8]; + + else + w = red; + } + + else + { + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff) + >> png_ptr->gamma_shift][red>>8]; + png_uint_16 green_1 = + png_ptr->gamma_16_to_1[(green & 0xff) >> + png_ptr->gamma_shift][green>>8]; + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff) + >> png_ptr->gamma_shift][blue>>8]; + png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 + + bc*blue_1 + 16384)>>15); + w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >> + png_ptr->gamma_shift][gray16 >> 8]; + rgb_error |= 1; + } + + *(dp++) = (png_byte)((w>>8) & 0xff); + *(dp++) = (png_byte)(w & 0xff); + + if (have_alpha != 0) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); + } + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, gray16; + png_byte hi,lo; + + hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); + hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); + + if (red != green || red != blue) + rgb_error |= 1; + + /* From 1.5.5 in the 16-bit case do the accurate conversion even + * in the 'fast' case - this is because this is where the code + * ends up when handling linear 16-bit data. + */ + gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> + 15); + *(dp++) = (png_byte)((gray16 >> 8) & 0xff); + *(dp++) = (png_byte)(gray16 & 0xff); + + if (have_alpha != 0) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); + } + } + } + } + + row_info->channels = (png_byte)(row_info->channels - 2); + row_info->color_type = (png_byte)(row_info->color_type & + ~PNG_COLOR_MASK_COLOR); + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + return rgb_error; +} +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) +/* Replace any alpha or transparency with the supplied background color. + * "background" is already in the screen gamma, while "background_1" is + * at a gamma of 1.0. Paletted files have already been taken care of. + */ +static void +png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr) +{ +#ifdef PNG_READ_GAMMA_SUPPORTED + png_const_bytep gamma_table = png_ptr->gamma_table; + png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; + png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; + png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; + png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; + png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; + int gamma_shift = png_ptr->gamma_shift; + int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; +#endif + + png_bytep sp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + int shift; + + png_debug(1, "in png_do_compose"); + + { + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_GRAY: + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row; + shift = 7; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x01) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x7f7f >> (7 - shift)); + tmp |= png_ptr->background.gray << shift; + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 7; + sp++; + } + + else + shift--; + } + break; + } + + case 2: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + shift = 6; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x03) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); + tmp |= png_ptr->background.gray << shift; + *sp = (png_byte)(tmp & 0xff); + } + + else + { + unsigned int p = (*sp >> shift) & 0x03; + unsigned int g = (gamma_table [p | (p << 2) | + (p << 4) | (p << 6)] >> 6) & 0x03; + unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); + tmp |= g << shift; + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 6; + sp++; + } + + else + shift -= 2; + } + } + + else +#endif + { + sp = row; + shift = 6; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x03) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); + tmp |= png_ptr->background.gray << shift; + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 6; + sp++; + } + + else + shift -= 2; + } + } + break; + } + + case 4: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + shift = 4; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x0f) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); + tmp |= png_ptr->background.gray << shift; + *sp = (png_byte)(tmp & 0xff); + } + + else + { + unsigned int p = (*sp >> shift) & 0x0f; + unsigned int g = (gamma_table[p | (p << 4)] >> 4) & + 0x0f; + unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); + tmp |= g << shift; + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 4; + sp++; + } + + else + shift -= 4; + } + } + + else +#endif + { + sp = row; + shift = 4; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x0f) + == png_ptr->trans_color.gray) + { + unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); + tmp |= png_ptr->background.gray << shift; + *sp = (png_byte)(tmp & 0xff); + } + + if (shift == 0) + { + shift = 4; + sp++; + } + + else + shift -= 4; + } + } + break; + } + + case 8: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp++) + { + if (*sp == png_ptr->trans_color.gray) + *sp = (png_byte)png_ptr->background.gray; + + else + *sp = gamma_table[*sp]; + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp++) + { + if (*sp == png_ptr->trans_color.gray) + *sp = (png_byte)png_ptr->background.gray; + } + } + break; + } + + case 16: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 v; + + v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + if (v == png_ptr->trans_color.gray) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray + & 0xff); + } + + else + { + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 v; + + v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + if (v == png_ptr->trans_color.gray) + { + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray + & 0xff); + } + } + } + break; + } + + default: + break; + } + break; + } + + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 3) + { + if (*sp == png_ptr->trans_color.red && + *(sp + 1) == png_ptr->trans_color.green && + *(sp + 2) == png_ptr->trans_color.blue) + { + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + + else + { + *sp = gamma_table[*sp]; + *(sp + 1) = gamma_table[*(sp + 1)]; + *(sp + 2) = gamma_table[*(sp + 2)]; + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 3) + { + if (*sp == png_ptr->trans_color.red && + *(sp + 1) == png_ptr->trans_color.green && + *(sp + 2) == png_ptr->trans_color.blue) + { + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 6) + { + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + if (r == png_ptr->trans_color.red && + g == png_ptr->trans_color.green && + b == png_ptr->trans_color.blue) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + + else + { + png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + } + } + + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 6) + { + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + if (r == png_ptr->trans_color.red && + g == png_ptr->trans_color.green && + b == png_ptr->trans_color.blue) + { + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + } + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 a = *(sp + 1); + + if (a == 0xff) + *sp = gamma_table[*sp]; + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)png_ptr->background.gray; + } + + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, png_ptr->background_1.gray); + if (optimize == 0) + w = gamma_from_1[w]; + *sp = w; + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_byte a = *(sp + 1); + + if (a == 0) + *sp = (png_byte)png_ptr->background.gray; + + else if (a < 0xff) + png_composite(*sp, *sp, a, png_ptr->background.gray); + } + } + } + else /* if (png_ptr->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); + } + + else + { + png_uint_16 g, v, w; + + g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(v, g, a, png_ptr->background_1.gray); + if (optimize != 0) + w = v; + else + w = gamma_16_from_1[(v & 0xff) >> + gamma_shift][v >> 8]; + *sp = (png_byte)((w >> 8) & 0xff); + *(sp + 1) = (png_byte)(w & 0xff); + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + if (a == 0) + { + *sp = (png_byte)((png_ptr->background.gray >> 8) + & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); + } + + else if (a < 0xffff) + { + png_uint_16 g, v; + + g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + png_composite_16(v, g, a, png_ptr->background.gray); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + } + } + } + break; + } + + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_byte a = *(sp + 3); + + if (a == 0xff) + { + *sp = gamma_table[*sp]; + *(sp + 1) = gamma_table[*(sp + 1)]; + *(sp + 2) = gamma_table[*(sp + 2)]; + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, png_ptr->background_1.red); + if (optimize == 0) w = gamma_from_1[w]; + *sp = w; + + v = gamma_to_1[*(sp + 1)]; + png_composite(w, v, a, png_ptr->background_1.green); + if (optimize == 0) w = gamma_from_1[w]; + *(sp + 1) = w; + + v = gamma_to_1[*(sp + 2)]; + png_composite(w, v, a, png_ptr->background_1.blue); + if (optimize == 0) w = gamma_from_1[w]; + *(sp + 2) = w; + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 4) + { + png_byte a = *(sp + 3); + + if (a == 0) + { + *sp = (png_byte)png_ptr->background.red; + *(sp + 1) = (png_byte)png_ptr->background.green; + *(sp + 2) = (png_byte)png_ptr->background.blue; + } + + else if (a < 0xff) + { + png_composite(*sp, *sp, a, png_ptr->background.red); + + png_composite(*(sp + 1), *(sp + 1), a, + png_ptr->background.green); + + png_composite(*(sp + 2), *(sp + 2), a, + png_ptr->background.blue); + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 8) + { + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) + << 8) + (png_uint_16)(*(sp + 7))); + + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + + else + { + png_uint_16 v, w; + + v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(w, v, a, png_ptr->background_1.red); + if (optimize == 0) + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> + 8]; + *sp = (png_byte)((w >> 8) & 0xff); + *(sp + 1) = (png_byte)(w & 0xff); + + v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; + png_composite_16(w, v, a, png_ptr->background_1.green); + if (optimize == 0) + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> + 8]; + + *(sp + 2) = (png_byte)((w >> 8) & 0xff); + *(sp + 3) = (png_byte)(w & 0xff); + + v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; + png_composite_16(w, v, a, png_ptr->background_1.blue); + if (optimize == 0) + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> + 8]; + + *(sp + 4) = (png_byte)((w >> 8) & 0xff); + *(sp + 5) = (png_byte)(w & 0xff); + } + } + } + + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 8) + { + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) + << 8) + (png_uint_16)(*(sp + 7))); + + if (a == 0) + { + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) + & 0xff); + *(sp + 3) = (png_byte)(png_ptr->background.green + & 0xff); + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) + & 0xff); + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); + } + + else if (a < 0xffff) + { + png_uint_16 v; + + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + png_composite_16(v, r, a, png_ptr->background.red); + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + + png_composite_16(v, g, a, png_ptr->background.green); + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + + png_composite_16(v, b, a, png_ptr->background.blue); + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + } + } + } + break; + } + + default: + break; + } + } +} +#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Gamma correct the image, avoiding the alpha channel. Make sure + * you do this after you deal with the transparency issue on grayscale + * or RGB images. If your bit depth is 8, use gamma_table, if it + * is 16, use gamma_16_table and gamma_shift. Build these with + * build_gamma_table(). + */ +static void +png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr) +{ + png_const_bytep gamma_table = png_ptr->gamma_table; + png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; + int gamma_shift = png_ptr->gamma_shift; + + png_bytep sp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_gamma"); + + if (((row_info->bit_depth <= 8 && gamma_table != NULL) || + (row_info->bit_depth == 16 && gamma_16_table != NULL))) + { + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + + *sp = gamma_table[*sp]; + sp++; + + *sp = gamma_table[*sp]; + sp++; + + sp++; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp += 2; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY: + { + if (row_info->bit_depth == 2) + { + sp = row; + for (i = 0; i < row_width; i += 4) + { + int a = *sp & 0xc0; + int b = *sp & 0x30; + int c = *sp & 0x0c; + int d = *sp & 0x03; + + *sp = (png_byte)( + ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| + ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| + ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| + ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); + sp++; + } + } + + if (row_info->bit_depth == 4) + { + sp = row; + for (i = 0; i < row_width; i += 2) + { + int msb = *sp & 0xf0; + int lsb = *sp & 0x0f; + + *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) + | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); + sp++; + } + } + + else if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + } + } + + else if (row_info->bit_depth == 16) + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + + default: + break; + } + } +} +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED +/* Encode the alpha channel to the output gamma (the input channel is always + * linear.) Called only with color types that have an alpha channel. Needs the + * from_1 tables. + */ +static void +png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr) +{ + png_uint_32 row_width = row_info->width; + + png_debug(1, "in png_do_encode_alpha"); + + if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + if (row_info->bit_depth == 8) + { + PNG_CONST png_bytep table = png_ptr->gamma_from_1; + + if (table != NULL) + { + PNG_CONST int step = + (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; + + /* The alpha channel is the last component: */ + row += step - 1; + + for (; row_width > 0; --row_width, row += step) + *row = table[*row]; + + return; + } + } + + else if (row_info->bit_depth == 16) + { + PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1; + PNG_CONST int gamma_shift = png_ptr->gamma_shift; + + if (table != NULL) + { + PNG_CONST int step = + (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; + + /* The alpha channel is the last component: */ + row += step - 2; + + for (; row_width > 0; --row_width, row += step) + { + png_uint_16 v; + + v = table[*(row + 1) >> gamma_shift][*row]; + *row = (png_byte)((v >> 8) & 0xff); + *(row + 1) = (png_byte)(v & 0xff); + } + + return; + } + } + } + + /* Only get to here if called with a weird row_info; no harm has been done, + * so just issue a warning. + */ + png_warning(png_ptr, "png_do_encode_alpha: unexpected call"); +} +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expands a palette row to an RGB or RGBA row depending + * upon whether you supply trans and num_trans. + */ +static void +png_do_expand_palette(png_row_infop row_info, png_bytep row, + png_const_colorp palette, png_const_bytep trans_alpha, int num_trans) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_expand_palette"); + + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row + (png_size_t)((row_width - 1) >> 3); + dp = row + (png_size_t)row_width - 1; + shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + if ((*sp >> shift) & 0x01) + *dp = 1; + + else + *dp = 0; + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + sp = row + (png_size_t)((row_width - 1) >> 2); + dp = row + (png_size_t)row_width - 1; + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x03; + *dp = (png_byte)value; + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + sp = row + (png_size_t)((row_width - 1) >> 1); + dp = row + (png_size_t)row_width - 1; + shift = (int)((row_width & 0x01) << 2); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x0f; + *dp = (png_byte)value; + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift += 4; + + dp--; + } + break; + } + + default: + break; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_width; + } + + if (row_info->bit_depth == 8) + { + { + if (num_trans > 0) + { + sp = row + (png_size_t)row_width - 1; + dp = row + (png_size_t)(row_width << 2) - 1; + + for (i = 0; i < row_width; i++) + { + if ((int)(*sp) >= num_trans) + *dp-- = 0xff; + + else + *dp-- = trans_alpha[*sp]; + + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + row_info->color_type = 6; + row_info->channels = 4; + } + + else + { + sp = row + (png_size_t)row_width - 1; + dp = row + (png_size_t)(row_width * 3) - 1; + + for (i = 0; i < row_width; i++) + { + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = 24; + row_info->rowbytes = row_width * 3; + row_info->color_type = 2; + row_info->channels = 3; + } + } + } + } +} + +/* If the bit depth < 8, it is expanded to 8. Also, if the already + * expanded transparency value is supplied, an alpha channel is built. + */ +static void +png_do_expand(png_row_infop row_info, png_bytep row, + png_const_color_16p trans_color) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_expand"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + unsigned int gray = trans_color != NULL ? trans_color->gray : 0; + + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + gray = (gray & 0x01) * 0xff; + sp = row + (png_size_t)((row_width - 1) >> 3); + dp = row + (png_size_t)row_width - 1; + shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + if ((*sp >> shift) & 0x01) + *dp = 0xff; + + else + *dp = 0; + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + gray = (gray & 0x03) * 0x55; + sp = row + (png_size_t)((row_width - 1) >> 2); + dp = row + (png_size_t)row_width - 1; + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x03; + *dp = (png_byte)(value | (value << 2) | (value << 4) | + (value << 6)); + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + gray = (gray & 0x0f) * 0x11; + sp = row + (png_size_t)((row_width - 1) >> 1); + dp = row + (png_size_t)row_width - 1; + shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x0f; + *dp = (png_byte)(value | (value << 4)); + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift = 4; + + dp--; + } + break; + } + + default: + break; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_width; + } + + if (trans_color != NULL) + { + if (row_info->bit_depth == 8) + { + gray = gray & 0xff; + sp = row + (png_size_t)row_width - 1; + dp = row + (png_size_t)(row_width << 1) - 1; + + for (i = 0; i < row_width; i++) + { + if ((*sp & 0xffU) == gray) + *dp-- = 0; + + else + *dp-- = 0xff; + + *dp-- = *sp--; + } + } + + else if (row_info->bit_depth == 16) + { + unsigned int gray_high = (gray >> 8) & 0xff; + unsigned int gray_low = gray & 0xff; + sp = row + row_info->rowbytes - 1; + dp = row + (row_info->rowbytes << 1) - 1; + for (i = 0; i < row_width; i++) + { + if ((*(sp - 1) & 0xffU) == gray_high && + (*(sp) & 0xffU) == gray_low) + { + *dp-- = 0; + *dp-- = 0; + } + + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + + *dp-- = *sp--; + *dp-- = *sp--; + } + } + + row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; + row_info->channels = 2; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_width); + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_RGB && + trans_color != NULL) + { + if (row_info->bit_depth == 8) + { + png_byte red = (png_byte)(trans_color->red & 0xff); + png_byte green = (png_byte)(trans_color->green & 0xff); + png_byte blue = (png_byte)(trans_color->blue & 0xff); + sp = row + (png_size_t)row_info->rowbytes - 1; + dp = row + (png_size_t)(row_width << 2) - 1; + for (i = 0; i < row_width; i++) + { + if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) + *dp-- = 0; + + else + *dp-- = 0xff; + + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + else if (row_info->bit_depth == 16) + { + png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff); + png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff); + png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff); + png_byte red_low = (png_byte)(trans_color->red & 0xff); + png_byte green_low = (png_byte)(trans_color->green & 0xff); + png_byte blue_low = (png_byte)(trans_color->blue & 0xff); + sp = row + row_info->rowbytes - 1; + dp = row + (png_size_t)(row_width << 3) - 1; + for (i = 0; i < row_width; i++) + { + if (*(sp - 5) == red_high && + *(sp - 4) == red_low && + *(sp - 3) == green_high && + *(sp - 2) == green_low && + *(sp - 1) == blue_high && + *(sp ) == blue_low) + { + *dp-- = 0; + *dp-- = 0; + } + + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + row_info->channels = 4; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + } +} +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* If the bit depth is 8 and the color type is not a palette type expand the + * whole row to 16 bits. Has no effect otherwise. + */ +static void +png_do_expand_16(png_row_infop row_info, png_bytep row) +{ + if (row_info->bit_depth == 8 && + row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + /* The row have a sequence of bytes containing [0..255] and we need + * to turn it into another row containing [0..65535], to do this we + * calculate: + * + * (input / 255) * 65535 + * + * Which happens to be exactly input * 257 and this can be achieved + * simply by byte replication in place (copying backwards). + */ + png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */ + png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */ + while (dp > sp) + dp[-2] = dp[-1] = *--sp, dp -= 2; + + row_info->rowbytes *= 2; + row_info->bit_depth = 16; + row_info->pixel_depth = (png_byte)(row_info->channels * 16); + } +} +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +static void +png_do_quantize(png_row_infop row_info, png_bytep row, + png_const_bytep palette_lookup, png_const_bytep quantize_lookup) +{ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_quantize"); + + if (row_info->bit_depth == 8) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + + /* This looks real messy, but the compiler will reduce + * it down to a reasonable formula. For example, with + * 5 bits per color, we get: + * p = (((r >> 3) & 0x1f) << 10) | + * (((g >> 3) & 0x1f) << 5) | + * ((b >> 3) & 0x1f); + */ + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << + (PNG_QUANTIZE_BLUE_BITS)) | + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && + palette_lookup != NULL) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + sp++; + + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << + (PNG_QUANTIZE_BLUE_BITS)) | + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + + else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && + quantize_lookup) + { + sp = row; + + for (i = 0; i < row_width; i++, sp++) + { + *sp = quantize_lookup[*sp]; + } + } + } +} +#endif /* READ_QUANTIZE */ + +/* Transform the row. The order of transformations is significant, + * and is very touchy. If you add a transformation, take care to + * decide how it fits in with the other transformations here. + */ +void /* PRIVATE */ +png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info) +{ + png_debug(1, "in png_do_read_transformations"); + + if (png_ptr->row_buf == NULL) + { + /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this + * error is incredibly rare and incredibly easy to debug without this + * information. + */ + png_error(png_ptr, "NULL row buffer"); + } + + /* The following is debugging; prior to 1.5.4 the code was never compiled in; + * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro + * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for + * all transformations, however in practice the ROW_INIT always gets done on + * demand, if necessary. + */ + if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 && + (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) + { + /* Application has failed to call either png_read_start_image() or + * png_read_update_info() after setting transforms that expand pixels. + * This check added to libpng-1.2.19 (but not enabled until 1.5.4). + */ + png_error(png_ptr, "Uninitialized row"); + } + +#ifdef PNG_READ_EXPAND_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_do_expand_palette(row_info, png_ptr->row_buf + 1, + png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); + } + + else + { + if (png_ptr->num_trans != 0 && + (png_ptr->transformations & PNG_EXPAND_tRNS) != 0) + png_do_expand(row_info, png_ptr->row_buf + 1, + &(png_ptr->trans_color)); + + else + png_do_expand(row_info, png_ptr->row_buf + 1, + NULL); + } + } +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && + (png_ptr->transformations & PNG_COMPOSE) == 0 && + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + 0 /* at_start == false, because SWAP_ALPHA happens later */); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) + { + int rgb_error = + png_do_rgb_to_gray(png_ptr, row_info, + png_ptr->row_buf + 1); + + if (rgb_error != 0) + { + png_ptr->rgb_to_gray_status=1; + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == + PNG_RGB_TO_GRAY_WARN) + png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); + + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == + PNG_RGB_TO_GRAY_ERR) + png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); + } + } +#endif + +/* From Andreas Dilger e-mail to png-implement, 26 March 1998: + * + * In most cases, the "simple transparency" should be done prior to doing + * gray-to-RGB, or you will have to test 3x as many bytes to check if a + * pixel is transparent. You would also need to make sure that the + * transparency information is upgraded to RGB. + * + * To summarize, the current flow is: + * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite + * with background "in place" if transparent, + * convert to RGB if necessary + * - Gray + alpha -> composite with gray background and remove alpha bytes, + * convert to RGB if necessary + * + * To support RGB backgrounds for gray images we need: + * - Gray + simple transparency -> convert to RGB + simple transparency, + * compare 3 or 6 bytes and composite with + * background "in place" if transparent + * (3x compare/pixel compared to doing + * composite with gray bkgrnd) + * - Gray + alpha -> convert to RGB + alpha, composite with background and + * remove alpha bytes (3x float + * operations/pixel compared with composite + * on gray background) + * + * Greg's change will do this. The reason it wasn't done before is for + * performance, as this increases the per-pixel operations. If we would check + * in advance if the background was gray or RGB, and position the gray-to-RGB + * transform appropriately, then it would save a lot of work/time. + */ + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* If gray -> RGB, do so now only if background is non-gray; else do later + * for performance reasons + */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0) + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + if ((png_ptr->transformations & PNG_COMPOSE) != 0) + png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + if ((png_ptr->transformations & PNG_GAMMA) != 0 && +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Because RGB_TO_GRAY does the gamma transform. */ + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 && +#endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + /* Because PNG_COMPOSE does the gamma transform if there is something to + * do (if there is an alpha channel or transparency.) + */ + !((png_ptr->transformations & PNG_COMPOSE) != 0 && + ((png_ptr->num_trans != 0) || + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) && +#endif + /* Because png_init_read_transformations transforms the palette, unless + * RGB_TO_GRAY will do the transform. + */ + (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) + png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && + (png_ptr->transformations & PNG_COMPOSE) != 0 && + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + 0 /* at_start == false, because SWAP_ALPHA happens later */); +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && + (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) + png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr); +#endif + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) + png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + /* There is no harm in doing both of these because only one has any effect, + * by putting the 'scale' option first if the app asks for scale (either by + * calling the API or in a TRANSFORM flag) this is what happens. + */ + if ((png_ptr->transformations & PNG_16_TO_8) != 0) + png_do_chop(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + if ((png_ptr->transformations & PNG_QUANTIZE) != 0) + { + png_do_quantize(row_info, png_ptr->row_buf + 1, + png_ptr->palette_lookup, png_ptr->quantize_index); + + if (row_info->rowbytes == 0) + png_error(png_ptr, "png_do_quantize returned rowbytes=0"); + } +#endif /* READ_QUANTIZE */ + +#ifdef PNG_READ_EXPAND_16_SUPPORTED + /* Do the expansion now, after all the arithmetic has been done. Notice + * that previous transformations can handle the PNG_EXPAND_16 flag if this + * is efficient (particularly true in the case of gamma correction, where + * better accuracy results faster!) + */ + if ((png_ptr->transformations & PNG_EXPAND_16) != 0) + png_do_expand_16(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* NOTE: moved here in 1.5.4 (from much later in this list.) */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0) + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_INVERT_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_do_invert(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) + png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_do_unshift(row_info, png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif + +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0) + png_do_unpack(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Added at libpng-1.5.10 */ + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && + png_ptr->num_palette_max >= 0) + png_do_check_palette_indexes(png_ptr, row_info); +#endif + +#ifdef PNG_READ_BGR_SUPPORTED + if ((png_ptr->transformations & PNG_BGR) != 0) + png_do_bgr(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_do_packswap(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_do_read_filler(row_info, png_ptr->row_buf + 1, + (png_uint_32)png_ptr->filler, png_ptr->flags); +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) + png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_16BIT_SUPPORTED +#ifdef PNG_READ_SWAP_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_do_swap(row_info, png_ptr->row_buf + 1); +#endif +#endif + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + { + if (png_ptr->read_user_transform_fn != NULL) + (*(png_ptr->read_user_transform_fn)) /* User read transform function */ + (png_ptr, /* png_ptr */ + row_info, /* row_info: */ + /* png_uint_32 width; width of row */ + /* png_size_t rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED + if (png_ptr->user_transform_depth != 0) + row_info->bit_depth = png_ptr->user_transform_depth; + + if (png_ptr->user_transform_channels != 0) + row_info->channels = png_ptr->user_transform_channels; +#endif + row_info->pixel_depth = (png_byte)(row_info->bit_depth * + row_info->channels); + + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width); + } +#endif +} + +#endif /* READ_TRANSFORMS */ +#endif /* READ */ diff --git a/thirdparty/libpng/pngrutil.c b/thirdparty/libpng/pngrutil.c new file mode 100644 index 0000000000..c9747fc27d --- /dev/null +++ b/thirdparty/libpng/pngrutil.c @@ -0,0 +1,4529 @@ + +/* pngrutil.c - utilities to read a PNG file + * + * Last changed in libpng 1.6.20 [December 3, 2014] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains routines that are only called from within + * libpng itself during the course of reading an image. + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +png_uint_32 PNGAPI +png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + + if (uval > PNG_UINT_31_MAX) + png_error(png_ptr, "PNG unsigned integer out of range"); + + return (uval); +} + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) +/* The following is a variation on the above for use with the fixed + * point values used for gAMA and cHRM. Instead of png_error it + * issues a warning and returns (-1) - an invalid value because both + * gAMA and cHRM use *unsigned* integers for fixed point values. + */ +#define PNG_FIXED_ERROR (-1) + +static png_fixed_point /* PRIVATE */ +png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + + if (uval <= PNG_UINT_31_MAX) + return (png_fixed_point)uval; /* known to be in range */ + + /* The caller can turn off the warning by passing NULL. */ + if (png_ptr != NULL) + png_warning(png_ptr, "PNG fixed point integer out of range"); + + return PNG_FIXED_ERROR; +} +#endif + +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +/* NOTE: the read macros will obscure these definitions, so that if + * PNG_USE_READ_MACROS is set the library will not use them internally, + * but the APIs will still be available externally. + * + * The parentheses around "PNGAPI function_name" in the following three + * functions are necessary because they allow the macros to co-exist with + * these (unused but exported) functions. + */ + +/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ +png_uint_32 (PNGAPI +png_get_uint_32)(png_const_bytep buf) +{ + png_uint_32 uval = + ((png_uint_32)(*(buf )) << 24) + + ((png_uint_32)(*(buf + 1)) << 16) + + ((png_uint_32)(*(buf + 2)) << 8) + + ((png_uint_32)(*(buf + 3)) ) ; + + return uval; +} + +/* Grab a signed 32-bit integer from a buffer in big-endian format. The + * data is stored in the PNG file in two's complement format and there + * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore + * the following code does a two's complement to native conversion. + */ +png_int_32 (PNGAPI +png_get_int_32)(png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + if ((uval & 0x80000000) == 0) /* non-negative */ + return uval; + + uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */ + if ((uval & 0x80000000) == 0) /* no overflow */ + return -(png_int_32)uval; + /* The following has to be safe; this function only gets called on PNG data + * and if we get here that data is invalid. 0 is the most safe value and + * if not then an attacker would surely just generate a PNG with 0 instead. + */ + return 0; +} + +/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ +png_uint_16 (PNGAPI +png_get_uint_16)(png_const_bytep buf) +{ + /* ANSI-C requires an int value to accomodate at least 16 bits so this + * works and allows the compiler not to worry about possible narrowing + * on 32-bit systems. (Pre-ANSI systems did not make integers smaller + * than 16 bits either.) + */ + unsigned int val = + ((unsigned int)(*buf) << 8) + + ((unsigned int)(*(buf + 1))); + + return (png_uint_16)val; +} + +#endif /* READ_INT_FUNCTIONS */ + +/* Read and check the PNG file signature */ +void /* PRIVATE */ +png_read_sig(png_structrp png_ptr, png_inforp info_ptr) +{ + png_size_t num_checked, num_to_check; + + /* Exit if the user application does not expect a signature. */ + if (png_ptr->sig_bytes >= 8) + return; + + num_checked = png_ptr->sig_bytes; + num_to_check = 8 - num_checked; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; +#endif + + /* The signature must be serialized in a single I/O call. */ + png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); + png_ptr->sig_bytes = 8; + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + if (num_checked < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Read the chunk header (length + type name). + * Put the type name into png_ptr->chunk_name, and return the length. + */ +png_uint_32 /* PRIVATE */ +png_read_chunk_header(png_structrp png_ptr) +{ + png_byte buf[8]; + png_uint_32 length; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; +#endif + + /* Read the length and the chunk name. + * This must be performed in a single I/O call. + */ + png_read_data(png_ptr, buf, 8); + length = png_get_uint_31(png_ptr, buf); + + /* Put the chunk name into png_ptr->chunk_name. */ + png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4); + + png_debug2(0, "Reading %lx chunk, length = %lu", + (unsigned long)png_ptr->chunk_name, (unsigned long)length); + + /* Reset the crc and run it over the chunk name. */ + png_reset_crc(png_ptr); + png_calculate_crc(png_ptr, buf + 4, 4); + + /* Check to see if chunk name is valid. */ + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; +#endif + + return length; +} + +/* Read data, and (optionally) run it through the CRC. */ +void /* PRIVATE */ +png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length) +{ + if (png_ptr == NULL) + return; + + png_read_data(png_ptr, buf, length); + png_calculate_crc(png_ptr, buf, length); +} + +/* Optionally skip data and then check the CRC. Depending on whether we + * are reading an ancillary or critical chunk, and how the program has set + * things up, we may calculate the CRC on the data and print a message. + * Returns '1' if there was a CRC error, '0' otherwise. + */ +int /* PRIVATE */ +png_crc_finish(png_structrp png_ptr, png_uint_32 skip) +{ + /* The size of the local buffer for inflate is a good guess as to a + * reasonable size to use for buffering reads from the application. + */ + while (skip > 0) + { + png_uint_32 len; + png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; + + len = (sizeof tmpbuf); + if (len > skip) + len = skip; + skip -= len; + + png_crc_read(png_ptr, tmpbuf, len); + } + + if (png_crc_error(png_ptr) != 0) + { + if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ? + (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 : + (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0) + { + png_chunk_warning(png_ptr, "CRC error"); + } + + else + png_chunk_error(png_ptr, "CRC error"); + + return (1); + } + + return (0); +} + +/* Compare the CRC stored in the PNG file with that calculated by libpng from + * the data it has read thus far. + */ +int /* PRIVATE */ +png_crc_error(png_structrp png_ptr) +{ + png_byte crc_bytes[4]; + png_uint_32 crc; + int need_crc = 1; + + if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0) + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + + else /* critical */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0) + need_crc = 0; + } + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; +#endif + + /* The chunk CRC must be serialized in a single I/O call. */ + png_read_data(png_ptr, crc_bytes, 4); + + if (need_crc != 0) + { + crc = png_get_uint_32(crc_bytes); + return ((int)(crc != png_ptr->crc)); + } + + else + return (0); +} + +#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\ + defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\ + defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\ + defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED) +/* Manage the read buffer; this simply reallocates the buffer if it is not small + * enough (or if it is not allocated). The routine returns a pointer to the + * buffer; if an error occurs and 'warn' is set the routine returns NULL, else + * it will call png_error (via png_malloc) on failure. (warn == 2 means + * 'silent'). + */ +static png_bytep +png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn) +{ + png_bytep buffer = png_ptr->read_buffer; + + if (buffer != NULL && new_size > png_ptr->read_buffer_size) + { + png_ptr->read_buffer = NULL; + png_ptr->read_buffer = NULL; + png_ptr->read_buffer_size = 0; + png_free(png_ptr, buffer); + buffer = NULL; + } + + if (buffer == NULL) + { + buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size)); + + if (buffer != NULL) + { + png_ptr->read_buffer = buffer; + png_ptr->read_buffer_size = new_size; + } + + else if (warn < 2) /* else silent */ + { + if (warn != 0) + png_chunk_warning(png_ptr, "insufficient memory to read chunk"); + + else + png_chunk_error(png_ptr, "insufficient memory to read chunk"); + } + } + + return buffer; +} +#endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */ + +/* png_inflate_claim: claim the zstream for some nefarious purpose that involves + * decompression. Returns Z_OK on success, else a zlib error code. It checks + * the owner but, in final release builds, just issues a warning if some other + * chunk apparently owns the stream. Prior to release it does a png_error. + */ +static int +png_inflate_claim(png_structrp png_ptr, png_uint_32 owner) +{ + if (png_ptr->zowner != 0) + { + char msg[64]; + + PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner); + /* So the message that results is "<chunk> using zstream"; this is an + * internal error, but is very useful for debugging. i18n requirements + * are minimal. + */ + (void)png_safecat(msg, (sizeof msg), 4, " using zstream"); +#if PNG_RELEASE_BUILD + png_chunk_warning(png_ptr, msg); + png_ptr->zowner = 0; +#else + png_chunk_error(png_ptr, msg); +#endif + } + + /* Implementation note: unlike 'png_deflate_claim' this internal function + * does not take the size of the data as an argument. Some efficiency could + * be gained by using this when it is known *if* the zlib stream itself does + * not record the number; however, this is an illusion: the original writer + * of the PNG may have selected a lower window size, and we really must + * follow that because, for systems with with limited capabilities, we + * would otherwise reject the application's attempts to use a smaller window + * size (zlib doesn't have an interface to say "this or lower"!). + * + * inflateReset2 was added to zlib 1.2.4; before this the window could not be + * reset, therefore it is necessary to always allocate the maximum window + * size with earlier zlibs just in case later compressed chunks need it. + */ + { + int ret; /* zlib return code */ +#if PNG_ZLIB_VERNUM >= 0x1240 + +# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW) + int window_bits; + + if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) == + PNG_OPTION_ON) + { + window_bits = 15; + png_ptr->zstream_start = 0; /* fixed window size */ + } + + else + { + window_bits = 0; + png_ptr->zstream_start = 1; + } +# else +# define window_bits 0 +# endif +#endif + + /* Set this for safety, just in case the previous owner left pointers to + * memory allocations. + */ + png_ptr->zstream.next_in = NULL; + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->zstream.avail_out = 0; + + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) + { +#if PNG_ZLIB_VERNUM < 0x1240 + ret = inflateReset(&png_ptr->zstream); +#else + ret = inflateReset2(&png_ptr->zstream, window_bits); +#endif + } + + else + { +#if PNG_ZLIB_VERNUM < 0x1240 + ret = inflateInit(&png_ptr->zstream); +#else + ret = inflateInit2(&png_ptr->zstream, window_bits); +#endif + + if (ret == Z_OK) + png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; + } + + if (ret == Z_OK) + png_ptr->zowner = owner; + + else + png_zstream_error(png_ptr, ret); + + return ret; + } + +#ifdef window_bits +# undef window_bits +#endif +} + +#if PNG_ZLIB_VERNUM >= 0x1240 +/* Handle the start of the inflate stream if we called inflateInit2(strm,0); + * in this case some zlib versions skip validation of the CINFO field and, in + * certain circumstances, libpng may end up displaying an invalid image, in + * contrast to implementations that call zlib in the normal way (e.g. libpng + * 1.5). + */ +int /* PRIVATE */ +png_zlib_inflate(png_structrp png_ptr, int flush) +{ + if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0) + { + if ((*png_ptr->zstream.next_in >> 4) > 7) + { + png_ptr->zstream.msg = "invalid window size (libpng)"; + return Z_DATA_ERROR; + } + + png_ptr->zstream_start = 0; + } + + return inflate(&png_ptr->zstream, flush); +} +#endif /* Zlib >= 1.2.4 */ + +#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED +/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to + * allow the caller to do multiple calls if required. If the 'finish' flag is + * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must + * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and + * Z_OK or Z_STREAM_END will be returned on success. + * + * The input and output sizes are updated to the actual amounts of data consumed + * or written, not the amount available (as in a z_stream). The data pointers + * are not changed, so the next input is (data+input_size) and the next + * available output is (output+output_size). + */ +static int +png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish, + /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr, + /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr) +{ + if (png_ptr->zowner == owner) /* Else not claimed */ + { + int ret; + png_alloc_size_t avail_out = *output_size_ptr; + png_uint_32 avail_in = *input_size_ptr; + + /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it + * can't even necessarily handle 65536 bytes) because the type uInt is + * "16 bits or more". Consequently it is necessary to chunk the input to + * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the + * maximum value that can be stored in a uInt.) It is possible to set + * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have + * a performance advantage, because it reduces the amount of data accessed + * at each step and that may give the OS more time to page it in. + */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); + /* avail_in and avail_out are set below from 'size' */ + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.avail_out = 0; + + /* Read directly into the output if it is available (this is set to + * a local buffer below if output is NULL). + */ + if (output != NULL) + png_ptr->zstream.next_out = output; + + do + { + uInt avail; + Byte local_buffer[PNG_INFLATE_BUF_SIZE]; + + /* zlib INPUT BUFFER */ + /* The setting of 'avail_in' used to be outside the loop; by setting it + * inside it is possible to chunk the input to zlib and simply rely on + * zlib to advance the 'next_in' pointer. This allows arbitrary + * amounts of data to be passed through zlib at the unavoidable cost of + * requiring a window save (memcpy of up to 32768 output bytes) + * every ZLIB_IO_MAX input bytes. + */ + avail_in += png_ptr->zstream.avail_in; /* not consumed last time */ + + avail = ZLIB_IO_MAX; + + if (avail_in < avail) + avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */ + + avail_in -= avail; + png_ptr->zstream.avail_in = avail; + + /* zlib OUTPUT BUFFER */ + avail_out += png_ptr->zstream.avail_out; /* not written last time */ + + avail = ZLIB_IO_MAX; /* maximum zlib can process */ + + if (output == NULL) + { + /* Reset the output buffer each time round if output is NULL and + * make available the full buffer, up to 'remaining_space' + */ + png_ptr->zstream.next_out = local_buffer; + if ((sizeof local_buffer) < avail) + avail = (sizeof local_buffer); + } + + if (avail_out < avail) + avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */ + + png_ptr->zstream.avail_out = avail; + avail_out -= avail; + + /* zlib inflate call */ + /* In fact 'avail_out' may be 0 at this point, that happens at the end + * of the read when the final LZ end code was not passed at the end of + * the previous chunk of input data. Tell zlib if we have reached the + * end of the output buffer. + */ + ret = PNG_INFLATE(png_ptr, avail_out > 0 ? Z_NO_FLUSH : + (finish ? Z_FINISH : Z_SYNC_FLUSH)); + } while (ret == Z_OK); + + /* For safety kill the local buffer pointer now */ + if (output == NULL) + png_ptr->zstream.next_out = NULL; + + /* Claw back the 'size' and 'remaining_space' byte counts. */ + avail_in += png_ptr->zstream.avail_in; + avail_out += png_ptr->zstream.avail_out; + + /* Update the input and output sizes; the updated values are the amount + * consumed or written, effectively the inverse of what zlib uses. + */ + if (avail_out > 0) + *output_size_ptr -= avail_out; + + if (avail_in > 0) + *input_size_ptr -= avail_in; + + /* Ensure png_ptr->zstream.msg is set (even in the success case!) */ + png_zstream_error(png_ptr, ret); + return ret; + } + + else + { + /* This is a bad internal error. The recovery assigns to the zstream msg + * pointer, which is not owned by the caller, but this is safe; it's only + * used on errors! + */ + png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); + return Z_STREAM_ERROR; + } +} + +/* + * Decompress trailing data in a chunk. The assumption is that read_buffer + * points at an allocated area holding the contents of a chunk with a + * trailing compressed part. What we get back is an allocated area + * holding the original prefix part and an uncompressed version of the + * trailing part (the malloc area passed in is freed). + */ +static int +png_decompress_chunk(png_structrp png_ptr, + png_uint_32 chunklength, png_uint_32 prefix_size, + png_alloc_size_t *newlength /* must be initialized to the maximum! */, + int terminate /*add a '\0' to the end of the uncompressed data*/) +{ + /* TODO: implement different limits for different types of chunk. + * + * The caller supplies *newlength set to the maximum length of the + * uncompressed data, but this routine allocates space for the prefix and + * maybe a '\0' terminator too. We have to assume that 'prefix_size' is + * limited only by the maximum chunk size. + */ + png_alloc_size_t limit = PNG_SIZE_MAX; + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_malloc_max > 0 && + png_ptr->user_chunk_malloc_max < limit) + limit = png_ptr->user_chunk_malloc_max; +# elif PNG_USER_CHUNK_MALLOC_MAX > 0 + if (PNG_USER_CHUNK_MALLOC_MAX < limit) + limit = PNG_USER_CHUNK_MALLOC_MAX; +# endif + + if (limit >= prefix_size + (terminate != 0)) + { + int ret; + + limit -= prefix_size + (terminate != 0); + + if (limit < *newlength) + *newlength = limit; + + /* Now try to claim the stream. */ + ret = png_inflate_claim(png_ptr, png_ptr->chunk_name); + + if (ret == Z_OK) + { + png_uint_32 lzsize = chunklength - prefix_size; + + ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, + /* input: */ png_ptr->read_buffer + prefix_size, &lzsize, + /* output: */ NULL, newlength); + + if (ret == Z_STREAM_END) + { + /* Use 'inflateReset' here, not 'inflateReset2' because this + * preserves the previously decided window size (otherwise it would + * be necessary to store the previous window size.) In practice + * this doesn't matter anyway, because png_inflate will call inflate + * with Z_FINISH in almost all cases, so the window will not be + * maintained. + */ + if (inflateReset(&png_ptr->zstream) == Z_OK) + { + /* Because of the limit checks above we know that the new, + * expanded, size will fit in a size_t (let alone an + * png_alloc_size_t). Use png_malloc_base here to avoid an + * extra OOM message. + */ + png_alloc_size_t new_size = *newlength; + png_alloc_size_t buffer_size = prefix_size + new_size + + (terminate != 0); + png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr, + buffer_size)); + + if (text != NULL) + { + ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/, + png_ptr->read_buffer + prefix_size, &lzsize, + text + prefix_size, newlength); + + if (ret == Z_STREAM_END) + { + if (new_size == *newlength) + { + if (terminate != 0) + text[prefix_size + *newlength] = 0; + + if (prefix_size > 0) + memcpy(text, png_ptr->read_buffer, prefix_size); + + { + png_bytep old_ptr = png_ptr->read_buffer; + + png_ptr->read_buffer = text; + png_ptr->read_buffer_size = buffer_size; + text = old_ptr; /* freed below */ + } + } + + else + { + /* The size changed on the second read, there can be no + * guarantee that anything is correct at this point. + * The 'msg' pointer has been set to "unexpected end of + * LZ stream", which is fine, but return an error code + * that the caller won't accept. + */ + ret = PNG_UNEXPECTED_ZLIB_RETURN; + } + } + + else if (ret == Z_OK) + ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */ + + /* Free the text pointer (this is the old read_buffer on + * success) + */ + png_free(png_ptr, text); + + /* This really is very benign, but it's still an error because + * the extra space may otherwise be used as a Trojan Horse. + */ + if (ret == Z_STREAM_END && + chunklength - prefix_size != lzsize) + png_chunk_benign_error(png_ptr, "extra compressed data"); + } + + else + { + /* Out of memory allocating the buffer */ + ret = Z_MEM_ERROR; + png_zstream_error(png_ptr, Z_MEM_ERROR); + } + } + + else + { + /* inflateReset failed, store the error message */ + png_zstream_error(png_ptr, ret); + + if (ret == Z_STREAM_END) + ret = PNG_UNEXPECTED_ZLIB_RETURN; + } + } + + else if (ret == Z_OK) + ret = PNG_UNEXPECTED_ZLIB_RETURN; + + /* Release the claimed stream */ + png_ptr->zowner = 0; + } + + else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */ + ret = PNG_UNEXPECTED_ZLIB_RETURN; + + return ret; + } + + else + { + /* Application/configuration limits exceeded */ + png_zstream_error(png_ptr, Z_MEM_ERROR); + return Z_MEM_ERROR; + } +} +#endif /* READ_COMPRESSED_TEXT */ + +#ifdef PNG_READ_iCCP_SUPPORTED +/* Perform a partial read and decompress, producing 'avail_out' bytes and + * reading from the current chunk as required. + */ +static int +png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size, + png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size, + int finish) +{ + if (png_ptr->zowner == png_ptr->chunk_name) + { + int ret; + + /* next_in and avail_in must have been initialized by the caller. */ + png_ptr->zstream.next_out = next_out; + png_ptr->zstream.avail_out = 0; /* set in the loop */ + + do + { + if (png_ptr->zstream.avail_in == 0) + { + if (read_size > *chunk_bytes) + read_size = (uInt)*chunk_bytes; + *chunk_bytes -= read_size; + + if (read_size > 0) + png_crc_read(png_ptr, read_buffer, read_size); + + png_ptr->zstream.next_in = read_buffer; + png_ptr->zstream.avail_in = read_size; + } + + if (png_ptr->zstream.avail_out == 0) + { + uInt avail = ZLIB_IO_MAX; + if (avail > *out_size) + avail = (uInt)*out_size; + *out_size -= avail; + + png_ptr->zstream.avail_out = avail; + } + + /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all + * the available output is produced; this allows reading of truncated + * streams. + */ + ret = PNG_INFLATE(png_ptr, + *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH)); + } + while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0)); + + *out_size += png_ptr->zstream.avail_out; + png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */ + + /* Ensure the error message pointer is always set: */ + png_zstream_error(png_ptr, ret); + return ret; + } + + else + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed"); + return Z_STREAM_ERROR; + } +} +#endif + +/* Read and check the IDHR chunk */ + +void /* PRIVATE */ +png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[13]; + png_uint_32 width, height; + int bit_depth, color_type, compression_type, filter_type; + int interlace_type; + + png_debug(1, "in png_handle_IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) != 0) + png_chunk_error(png_ptr, "out of place"); + + /* Check the length */ + if (length != 13) + png_chunk_error(png_ptr, "invalid"); + + png_ptr->mode |= PNG_HAVE_IHDR; + + png_crc_read(png_ptr, buf, 13); + png_crc_finish(png_ptr, 0); + + width = png_get_uint_31(png_ptr, buf); + height = png_get_uint_31(png_ptr, buf + 4); + bit_depth = buf[8]; + color_type = buf[9]; + compression_type = buf[10]; + filter_type = buf[11]; + interlace_type = buf[12]; + + /* Set internal variables */ + png_ptr->width = width; + png_ptr->height = height; + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->interlaced = (png_byte)interlace_type; + png_ptr->color_type = (png_byte)color_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + + /* Find number of channels */ + switch (png_ptr->color_type) + { + default: /* invalid, png_set_IHDR calls png_error */ + case PNG_COLOR_TYPE_GRAY: + case PNG_COLOR_TYPE_PALETTE: + png_ptr->channels = 1; + break; + + case PNG_COLOR_TYPE_RGB: + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: + png_ptr->channels = 4; + break; + } + + /* Set up other useful info */ + png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width); + png_debug1(3, "bit_depth = %d", png_ptr->bit_depth); + png_debug1(3, "channels = %d", png_ptr->channels); + png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes); + png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, + color_type, interlace_type, compression_type, filter_type); +} + +/* Read and check the palette */ +void /* PRIVATE */ +png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_color palette[PNG_MAX_PALETTE_LENGTH]; + int max_palette_length, num, i; +#ifdef PNG_POINTER_INDEXING_SUPPORTED + png_colorp pal_ptr; +#endif + + png_debug(1, "in png_handle_PLTE"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + /* Moved to before the 'after IDAT' check below because otherwise duplicate + * PLTE chunks are potentially ignored (the spec says there shall not be more + * than one PLTE, the error is not treated as benign, so this check trumps + * the requirement that PLTE appears before IDAT.) + */ + else if ((png_ptr->mode & PNG_HAVE_PLTE) != 0) + png_chunk_error(png_ptr, "duplicate"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + /* This is benign because the non-benign error happened before, when an + * IDAT was encountered in a color-mapped image with no PLTE. + */ + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + png_ptr->mode |= PNG_HAVE_PLTE; + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "ignored in grayscale PNG"); + return; + } + +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_crc_finish(png_ptr, length); + return; + } +#endif + + if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3) + { + png_crc_finish(png_ptr, length); + + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + png_chunk_benign_error(png_ptr, "invalid"); + + else + png_chunk_error(png_ptr, "invalid"); + + return; + } + + /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */ + num = (int)length / 3; + + /* If the palette has 256 or fewer entries but is too large for the bit + * depth, we don't issue an error, to preserve the behavior of previous + * libpng versions. We silently truncate the unused extra palette entries + * here. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + max_palette_length = (1 << png_ptr->bit_depth); + else + max_palette_length = PNG_MAX_PALETTE_LENGTH; + + if (num > max_palette_length) + num = max_palette_length; + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + pal_ptr->red = buf[0]; + pal_ptr->green = buf[1]; + pal_ptr->blue = buf[2]; + } +#else + for (i = 0; i < num; i++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + /* Don't depend upon png_color being any order */ + palette[i].red = buf[0]; + palette[i].green = buf[1]; + palette[i].blue = buf[2]; + } +#endif + + /* If we actually need the PLTE chunk (ie for a paletted image), we do + * whatever the normal CRC configuration tells us. However, if we + * have an RGB image, the PLTE can be considered ancillary, so + * we will act as though it is. + */ +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#endif + { + png_crc_finish(png_ptr, (int) length - num * 3); + } + +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + else if (png_crc_error(png_ptr) != 0) /* Only if we have a CRC error */ + { + /* If we don't want to use the data from an ancillary chunk, + * we have two options: an error abort, or a warning and we + * ignore the data in this chunk (which should be OK, since + * it's considered ancillary for a RGB or RGBA image). + * + * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the + * chunk type to determine whether to check the ancillary or the critical + * flags. + */ + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE) == 0) + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) != 0) + return; + + else + png_chunk_error(png_ptr, "CRC error"); + } + + /* Otherwise, we (optionally) emit a warning and use the chunk. */ + else if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0) + png_chunk_warning(png_ptr, "CRC error"); + } +#endif + + /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its + * own copy of the palette. This has the side effect that when png_start_row + * is called (this happens after any call to png_read_update_info) the + * info_ptr palette gets changed. This is extremely unexpected and + * confusing. + * + * Fix this by not sharing the palette in this way. + */ + png_set_PLTE(png_ptr, info_ptr, palette, num); + + /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before + * IDAT. Prior to 1.6.0 this was not checked; instead the code merely + * checked the apparent validity of a tRNS chunk inserted before PLTE on a + * palette PNG. 1.6.0 attempts to rigorously follow the standard and + * therefore does a benign error if the erroneous condition is detected *and* + * cancels the tRNS if the benign error returns. The alternative is to + * amend the standard since it would be rather hypocritical of the standards + * maintainers to ignore it. + */ +#ifdef PNG_READ_tRNS_SUPPORTED + if (png_ptr->num_trans > 0 || + (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0)) + { + /* Cancel this because otherwise it would be used if the transforms + * require it. Don't cancel the 'valid' flag because this would prevent + * detection of duplicate chunks. + */ + png_ptr->num_trans = 0; + + if (info_ptr != NULL) + info_ptr->num_trans = 0; + + png_chunk_benign_error(png_ptr, "tRNS must be after"); + } +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0) + png_chunk_benign_error(png_ptr, "hIST must be after"); +#endif + +#ifdef PNG_READ_bKGD_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0) + png_chunk_benign_error(png_ptr, "bKGD must be after"); +#endif +} + +void /* PRIVATE */ +png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_debug(1, "in png_handle_IEND"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0 || + (png_ptr->mode & PNG_HAVE_IDAT) == 0) + png_chunk_error(png_ptr, "out of place"); + + png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); + + png_crc_finish(png_ptr, length); + + if (length != 0) + png_chunk_benign_error(png_ptr, "invalid"); + + PNG_UNUSED(info_ptr) +} + +#ifdef PNG_READ_gAMA_SUPPORTED +void /* PRIVATE */ +png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_fixed_point igamma; + png_byte buf[4]; + + png_debug(1, "in png_handle_gAMA"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length != 4) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 4); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + igamma = png_get_fixed_point(NULL, buf); + + png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma); + png_colorspace_sync(png_ptr, info_ptr); +} +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED +void /* PRIVATE */ +png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + unsigned int truelen, i; + png_byte sample_depth; + png_byte buf[4]; + + png_debug(1, "in png_handle_sBIT"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + truelen = 3; + sample_depth = 8; + } + + else + { + truelen = png_ptr->channels; + sample_depth = png_ptr->bit_depth; + } + + if (length != truelen || length > 4) + { + png_chunk_benign_error(png_ptr, "invalid"); + png_crc_finish(png_ptr, length); + return; + } + + buf[0] = buf[1] = buf[2] = buf[3] = sample_depth; + png_crc_read(png_ptr, buf, truelen); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + for (i=0; i<truelen; ++i) + { + if (buf[i] == 0 || buf[i] > sample_depth) + { + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + } + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[1]; + png_ptr->sig_bit.blue = buf[2]; + png_ptr->sig_bit.alpha = buf[3]; + } + + else + { + png_ptr->sig_bit.gray = buf[0]; + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[0]; + png_ptr->sig_bit.blue = buf[0]; + png_ptr->sig_bit.alpha = buf[1]; + } + + png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); +} +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED +void /* PRIVATE */ +png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[32]; + png_xy xy; + + png_debug(1, "in png_handle_cHRM"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length != 32) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 32); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + xy.whitex = png_get_fixed_point(NULL, buf); + xy.whitey = png_get_fixed_point(NULL, buf + 4); + xy.redx = png_get_fixed_point(NULL, buf + 8); + xy.redy = png_get_fixed_point(NULL, buf + 12); + xy.greenx = png_get_fixed_point(NULL, buf + 16); + xy.greeny = png_get_fixed_point(NULL, buf + 20); + xy.bluex = png_get_fixed_point(NULL, buf + 24); + xy.bluey = png_get_fixed_point(NULL, buf + 28); + + if (xy.whitex == PNG_FIXED_ERROR || + xy.whitey == PNG_FIXED_ERROR || + xy.redx == PNG_FIXED_ERROR || + xy.redy == PNG_FIXED_ERROR || + xy.greenx == PNG_FIXED_ERROR || + xy.greeny == PNG_FIXED_ERROR || + xy.bluex == PNG_FIXED_ERROR || + xy.bluey == PNG_FIXED_ERROR) + { + png_chunk_benign_error(png_ptr, "invalid values"); + return; + } + + /* If a colorspace error has already been output skip this chunk */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + return; + + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0) + { + png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; + png_colorspace_sync(png_ptr, info_ptr); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; + (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy, + 1/*prefer cHRM values*/); + png_colorspace_sync(png_ptr, info_ptr); +} +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED +void /* PRIVATE */ +png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte intent; + + png_debug(1, "in png_handle_sRGB"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length != 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, &intent, 1); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* If a colorspace error has already been output skip this chunk */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + return; + + /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect + * this. + */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) != 0) + { + png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; + png_colorspace_sync(png_ptr, info_ptr); + png_chunk_benign_error(png_ptr, "too many profiles"); + return; + } + + (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent); + png_colorspace_sync(png_ptr, info_ptr); +} +#endif /* READ_sRGB */ + +#ifdef PNG_READ_iCCP_SUPPORTED +void /* PRIVATE */ +png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +/* Note: this does not properly handle profiles that are > 64K under DOS */ +{ + png_const_charp errmsg = NULL; /* error message output, or no error */ + int finished = 0; /* crc checked */ + + png_debug(1, "in png_handle_iCCP"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + /* Consistent with all the above colorspace handling an obviously *invalid* + * chunk is just ignored, so does not invalidate the color space. An + * alternative is to set the 'invalid' flags at the start of this routine + * and only clear them in they were not set before and all the tests pass. + * The minimum 'deflate' stream is assumed to be just the 2 byte header and + * 4 byte checksum. The keyword must be at least one character and there is + * a terminator (0) byte and the compression method. + */ + if (length < 9) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too short"); + return; + } + + /* If a colorspace error has already been output skip this chunk */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0) + { + png_crc_finish(png_ptr, length); + return; + } + + /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect + * this. + */ + if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0) + { + uInt read_length, keyword_length; + char keyword[81]; + + /* Find the keyword; the keyword plus separator and compression method + * bytes can be at most 81 characters long. + */ + read_length = 81; /* maximum */ + if (read_length > length) + read_length = (uInt)length; + + png_crc_read(png_ptr, (png_bytep)keyword, read_length); + length -= read_length; + + keyword_length = 0; + while (keyword_length < 80 && keyword_length < read_length && + keyword[keyword_length] != 0) + ++keyword_length; + + /* TODO: make the keyword checking common */ + if (keyword_length >= 1 && keyword_length <= 79) + { + /* We only understand '0' compression - deflate - so if we get a + * different value we can't safely decode the chunk. + */ + if (keyword_length+1 < read_length && + keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE) + { + read_length -= keyword_length+2; + + if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK) + { + Byte profile_header[132]; + Byte local_buffer[PNG_INFLATE_BUF_SIZE]; + png_alloc_size_t size = (sizeof profile_header); + + png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2); + png_ptr->zstream.avail_in = read_length; + (void)png_inflate_read(png_ptr, local_buffer, + (sizeof local_buffer), &length, profile_header, &size, + 0/*finish: don't, because the output is too small*/); + + if (size == 0) + { + /* We have the ICC profile header; do the basic header checks. + */ + const png_uint_32 profile_length = + png_get_uint_32(profile_header); + + if (png_icc_check_length(png_ptr, &png_ptr->colorspace, + keyword, profile_length) != 0) + { + /* The length is apparently ok, so we can check the 132 + * byte header. + */ + if (png_icc_check_header(png_ptr, &png_ptr->colorspace, + keyword, profile_length, profile_header, + png_ptr->color_type) != 0) + { + /* Now read the tag table; a variable size buffer is + * needed at this point, allocate one for the whole + * profile. The header check has already validated + * that none of these stuff will overflow. + */ + const png_uint_32 tag_count = png_get_uint_32( + profile_header+128); + png_bytep profile = png_read_buffer(png_ptr, + profile_length, 2/*silent*/); + + if (profile != NULL) + { + memcpy(profile, profile_header, + (sizeof profile_header)); + + size = 12 * tag_count; + + (void)png_inflate_read(png_ptr, local_buffer, + (sizeof local_buffer), &length, + profile + (sizeof profile_header), &size, 0); + + /* Still expect a buffer error because we expect + * there to be some tag data! + */ + if (size == 0) + { + if (png_icc_check_tag_table(png_ptr, + &png_ptr->colorspace, keyword, profile_length, + profile) != 0) + { + /* The profile has been validated for basic + * security issues, so read the whole thing in. + */ + size = profile_length - (sizeof profile_header) + - 12 * tag_count; + + (void)png_inflate_read(png_ptr, local_buffer, + (sizeof local_buffer), &length, + profile + (sizeof profile_header) + + 12 * tag_count, &size, 1/*finish*/); + + if (length > 0 && !(png_ptr->flags & + PNG_FLAG_BENIGN_ERRORS_WARN)) + errmsg = "extra compressed data"; + + /* But otherwise allow extra data: */ + else if (size == 0) + { + if (length > 0) + { + /* This can be handled completely, so + * keep going. + */ + png_chunk_warning(png_ptr, + "extra compressed data"); + } + + png_crc_finish(png_ptr, length); + finished = 1; + +# ifdef PNG_sRGB_SUPPORTED + /* Check for a match against sRGB */ + png_icc_set_sRGB(png_ptr, + &png_ptr->colorspace, profile, + png_ptr->zstream.adler); +# endif + + /* Steal the profile for info_ptr. */ + if (info_ptr != NULL) + { + png_free_data(png_ptr, info_ptr, + PNG_FREE_ICCP, 0); + + info_ptr->iccp_name = png_voidcast(char*, + png_malloc_base(png_ptr, + keyword_length+1)); + if (info_ptr->iccp_name != NULL) + { + memcpy(info_ptr->iccp_name, keyword, + keyword_length+1); + info_ptr->iccp_proflen = + profile_length; + info_ptr->iccp_profile = profile; + png_ptr->read_buffer = NULL; /*steal*/ + info_ptr->free_me |= PNG_FREE_ICCP; + info_ptr->valid |= PNG_INFO_iCCP; + } + + else + { + png_ptr->colorspace.flags |= + PNG_COLORSPACE_INVALID; + errmsg = "out of memory"; + } + } + + /* else the profile remains in the read + * buffer which gets reused for subsequent + * chunks. + */ + + if (info_ptr != NULL) + png_colorspace_sync(png_ptr, info_ptr); + + if (errmsg == NULL) + { + png_ptr->zowner = 0; + return; + } + } + + else if (size > 0) + errmsg = "truncated"; + +#ifndef __COVERITY__ + else + errmsg = png_ptr->zstream.msg; +#endif + } + + /* else png_icc_check_tag_table output an error */ + } + + else /* profile truncated */ + errmsg = png_ptr->zstream.msg; + } + + else + errmsg = "out of memory"; + } + + /* else png_icc_check_header output an error */ + } + + /* else png_icc_check_length output an error */ + } + + else /* profile truncated */ + errmsg = png_ptr->zstream.msg; + + /* Release the stream */ + png_ptr->zowner = 0; + } + + else /* png_inflate_claim failed */ + errmsg = png_ptr->zstream.msg; + } + + else + errmsg = "bad compression method"; /* or missing */ + } + + else + errmsg = "bad keyword"; + } + + else + errmsg = "too many profiles"; + + /* Failure: the reason is in 'errmsg' */ + if (finished == 0) + png_crc_finish(png_ptr, length); + + png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID; + png_colorspace_sync(png_ptr, info_ptr); + if (errmsg != NULL) /* else already output */ + png_chunk_benign_error(png_ptr, errmsg); +} +#endif /* READ_iCCP */ + +#ifdef PNG_READ_sPLT_SUPPORTED +void /* PRIVATE */ +png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +/* Note: this does not properly handle chunks that are > 64K under DOS */ +{ + png_bytep entry_start, buffer; + png_sPLT_t new_palette; + png_sPLT_entryp pp; + png_uint_32 data_length; + int entry_size, i; + png_uint_32 skip = 0; + png_uint_32 dl; + png_size_t max_dl; + + png_debug(1, "in png_handle_sPLT"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for sPLT"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + +#ifdef PNG_MAX_MALLOC_64K + if (length > 65535U) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too large to fit in memory"); + return; + } +#endif + + buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + + /* WARNING: this may break if size_t is less than 32 bits; it is assumed + * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a + * potential breakage point if the types in pngconf.h aren't exactly right. + */ + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, skip) != 0) + return; + + buffer[length] = 0; + + for (entry_start = buffer; *entry_start; entry_start++) + /* Empty loop to find end of name */ ; + + ++entry_start; + + /* A sample depth should follow the separator, and we should be on it */ + if (length < 2U || entry_start > buffer + (length - 2U)) + { + png_warning(png_ptr, "malformed sPLT chunk"); + return; + } + + new_palette.depth = *entry_start++; + entry_size = (new_palette.depth == 8 ? 6 : 10); + /* This must fit in a png_uint_32 because it is derived from the original + * chunk data length. + */ + data_length = length - (png_uint_32)(entry_start - buffer); + + /* Integrity-check the data length */ + if ((data_length % entry_size) != 0) + { + png_warning(png_ptr, "sPLT chunk has bad length"); + return; + } + + dl = (png_int_32)(data_length / entry_size); + max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry)); + + if (dl > max_dl) + { + png_warning(png_ptr, "sPLT chunk too long"); + return; + } + + new_palette.nentries = (png_int_32)(data_length / entry_size); + + new_palette.entries = (png_sPLT_entryp)png_malloc_warn( + png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry))); + + if (new_palette.entries == NULL) + { + png_warning(png_ptr, "sPLT chunk requires too much memory"); + return; + } + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0; i < new_palette.nentries; i++) + { + pp = new_palette.entries + i; + + if (new_palette.depth == 8) + { + pp->red = *entry_start++; + pp->green = *entry_start++; + pp->blue = *entry_start++; + pp->alpha = *entry_start++; + } + + else + { + pp->red = png_get_uint_16(entry_start); entry_start += 2; + pp->green = png_get_uint_16(entry_start); entry_start += 2; + pp->blue = png_get_uint_16(entry_start); entry_start += 2; + pp->alpha = png_get_uint_16(entry_start); entry_start += 2; + } + + pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#else + pp = new_palette.entries; + + for (i = 0; i < new_palette.nentries; i++) + { + + if (new_palette.depth == 8) + { + pp[i].red = *entry_start++; + pp[i].green = *entry_start++; + pp[i].blue = *entry_start++; + pp[i].alpha = *entry_start++; + } + + else + { + pp[i].red = png_get_uint_16(entry_start); entry_start += 2; + pp[i].green = png_get_uint_16(entry_start); entry_start += 2; + pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; + pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; + } + + pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#endif + + /* Discard all chunk data except the name and stash that */ + new_palette.name = (png_charp)buffer; + + png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); + + png_free(png_ptr, new_palette.entries); +} +#endif /* READ_sPLT */ + +#ifdef PNG_READ_tRNS_SUPPORTED +void /* PRIVATE */ +png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_tRNS"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + png_byte buf[2]; + + if (length != 2) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 2); + png_ptr->num_trans = 1; + png_ptr->trans_color.gray = png_get_uint_16(buf); + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + png_byte buf[6]; + + if (length != 6) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, length); + png_ptr->num_trans = 1; + png_ptr->trans_color.red = png_get_uint_16(buf); + png_ptr->trans_color.green = png_get_uint_16(buf + 2); + png_ptr->trans_color.blue = png_get_uint_16(buf + 4); + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if ((png_ptr->mode & PNG_HAVE_PLTE) == 0) + { + /* TODO: is this actually an error in the ISO spec? */ + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + if (length > (unsigned int) png_ptr->num_palette || + length > (unsigned int) PNG_MAX_PALETTE_LENGTH || + length == 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, readbuf, length); + png_ptr->num_trans = (png_uint_16)length; + } + + else + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid with alpha channel"); + return; + } + + if (png_crc_finish(png_ptr, 0) != 0) + { + png_ptr->num_trans = 0; + return; + } + + /* TODO: this is a horrible side effect in the palette case because the + * png_struct ends up with a pointer to the tRNS buffer owned by the + * png_info. Fix this. + */ + png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, + &(png_ptr->trans_color)); +} +#endif + +#ifdef PNG_READ_bKGD_SUPPORTED +void /* PRIVATE */ +png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + unsigned int truelen; + png_byte buf[6]; + png_color_16 background; + + png_debug(1, "in png_handle_bKGD"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + (png_ptr->mode & PNG_HAVE_PLTE) == 0)) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 1; + + else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + truelen = 6; + + else + truelen = 2; + + if (length != truelen) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, truelen); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* We convert the index value into RGB components so that we can allow + * arbitrary RGB values for background when we have transparency, and + * so it is easy to determine the RGB values of the background color + * from the info_ptr struct. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + background.index = buf[0]; + + if (info_ptr != NULL && info_ptr->num_palette != 0) + { + if (buf[0] >= info_ptr->num_palette) + { + png_chunk_benign_error(png_ptr, "invalid index"); + return; + } + + background.red = (png_uint_16)png_ptr->palette[buf[0]].red; + background.green = (png_uint_16)png_ptr->palette[buf[0]].green; + background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; + } + + else + background.red = background.green = background.blue = 0; + + background.gray = 0; + } + + else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) /* GRAY */ + { + background.index = 0; + background.red = + background.green = + background.blue = + background.gray = png_get_uint_16(buf); + } + + else + { + background.index = 0; + background.red = png_get_uint_16(buf); + background.green = png_get_uint_16(buf + 2); + background.blue = png_get_uint_16(buf + 4); + background.gray = 0; + } + + png_set_bKGD(png_ptr, info_ptr, &background); +} +#endif + +#ifdef PNG_READ_hIST_SUPPORTED +void /* PRIVATE */ +png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + unsigned int num, i; + png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_hIST"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 || + (png_ptr->mode & PNG_HAVE_PLTE) == 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + num = length / 2 ; + + if (num != (unsigned int) png_ptr->num_palette || + num > (unsigned int) PNG_MAX_PALETTE_LENGTH) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + for (i = 0; i < num; i++) + { + png_byte buf[2]; + + png_crc_read(png_ptr, buf, 2); + readbuf[i] = png_get_uint_16(buf); + } + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + png_set_hIST(png_ptr, info_ptr, readbuf); +} +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED +void /* PRIVATE */ +png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_uint_32 res_x, res_y; + int unit_type; + + png_debug(1, "in png_handle_pHYs"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (length != 9) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 9); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + res_x = png_get_uint_32(buf); + res_y = png_get_uint_32(buf + 4); + unit_type = buf[8]; + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); +} +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED +void /* PRIVATE */ +png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_int_32 offset_x, offset_y; + int unit_type; + + png_debug(1, "in png_handle_oFFs"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if (length != 9) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 9); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + offset_x = png_get_int_32(buf); + offset_y = png_get_int_32(buf + 4); + unit_type = buf[8]; + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); +} +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED +/* Read the pCAL chunk (described in the PNG Extensions document) */ +void /* PRIVATE */ +png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_int_32 X0, X1; + png_byte type, nparams; + png_bytep buffer, buf, units, endptr; + png_charpp params; + int i; + + png_debug(1, "in png_handle_pCAL"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)", + length + 1); + + buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); + + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + buffer[length] = 0; /* Null terminate the last string */ + + png_debug(3, "Finding end of pCAL purpose string"); + for (buf = buffer; *buf; buf++) + /* Empty loop */ ; + + endptr = buffer + length; + + /* We need to have at least 12 bytes after the purpose string + * in order to get the parameter information. + */ + if (endptr - buf <= 12) + { + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_debug(3, "Reading pCAL X0, X1, type, nparams, and units"); + X0 = png_get_int_32((png_bytep)buf+1); + X1 = png_get_int_32((png_bytep)buf+5); + type = buf[9]; + nparams = buf[10]; + units = buf + 11; + + png_debug(3, "Checking pCAL equation type and number of parameters"); + /* Check that we have the right number of parameters for known + * equation types. + */ + if ((type == PNG_EQUATION_LINEAR && nparams != 2) || + (type == PNG_EQUATION_BASE_E && nparams != 3) || + (type == PNG_EQUATION_ARBITRARY && nparams != 3) || + (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) + { + png_chunk_benign_error(png_ptr, "invalid parameter count"); + return; + } + + else if (type >= PNG_EQUATION_LAST) + { + png_chunk_benign_error(png_ptr, "unrecognized equation type"); + } + + for (buf = units; *buf; buf++) + /* Empty loop to move past the units string. */ ; + + png_debug(3, "Allocating pCAL parameters array"); + + params = png_voidcast(png_charpp, png_malloc_warn(png_ptr, + nparams * (sizeof (png_charp)))); + + if (params == NULL) + { + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + /* Get pointers to the start of each parameter string. */ + for (i = 0; i < nparams; i++) + { + buf++; /* Skip the null string terminator from previous parameter. */ + + png_debug1(3, "Reading pCAL parameter %d", i); + + for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++) + /* Empty loop to move past each parameter string */ ; + + /* Make sure we haven't run out of data yet */ + if (buf > endptr) + { + png_free(png_ptr, params); + png_chunk_benign_error(png_ptr, "invalid data"); + return; + } + } + + png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams, + (png_charp)units, params); + + png_free(png_ptr, params); +} +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED +/* Read the sCAL chunk */ +void /* PRIVATE */ +png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_bytep buffer; + png_size_t i; + int state; + + png_debug(1, "in png_handle_sCAL"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of place"); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + /* Need unit type, width, \0, height: minimum 4 bytes */ + else if (length < 4) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", + length + 1); + + buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/); + + if (buffer == NULL) + { + png_chunk_benign_error(png_ptr, "out of memory"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buffer, length); + buffer[length] = 0; /* Null terminate the last string */ + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* Validate the unit. */ + if (buffer[0] != 1 && buffer[0] != 2) + { + png_chunk_benign_error(png_ptr, "invalid unit"); + return; + } + + /* Validate the ASCII numbers, need two ASCII numbers separated by + * a '\0' and they need to fit exactly in the chunk data. + */ + i = 1; + state = 0; + + if (png_check_fp_number((png_const_charp)buffer, length, &state, &i) == 0 || + i >= length || buffer[i++] != 0) + png_chunk_benign_error(png_ptr, "bad width format"); + + else if (PNG_FP_IS_POSITIVE(state) == 0) + png_chunk_benign_error(png_ptr, "non-positive width"); + + else + { + png_size_t heighti = i; + + state = 0; + if (png_check_fp_number((png_const_charp)buffer, length, + &state, &i) == 0 || i != length) + png_chunk_benign_error(png_ptr, "bad height format"); + + else if (PNG_FP_IS_POSITIVE(state) == 0) + png_chunk_benign_error(png_ptr, "non-positive height"); + + else + /* This is the (only) success case. */ + png_set_sCAL_s(png_ptr, info_ptr, buffer[0], + (png_charp)buffer+1, (png_charp)buffer+heighti); + } +} +#endif + +#ifdef PNG_READ_tIME_SUPPORTED +void /* PRIVATE */ +png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_byte buf[7]; + png_time mod_time; + + png_debug(1, "in png_handle_tIME"); + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) != 0) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "duplicate"); + return; + } + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + + if (length != 7) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "invalid"); + return; + } + + png_crc_read(png_ptr, buf, 7); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + mod_time.second = buf[6]; + mod_time.minute = buf[5]; + mod_time.hour = buf[4]; + mod_time.day = buf[3]; + mod_time.month = buf[2]; + mod_time.year = png_get_uint_16(buf); + + png_set_tIME(png_ptr, info_ptr, &mod_time); +} +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED +/* Note: this does not properly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_text text_info; + png_bytep buffer; + png_charp key; + png_charp text; + png_uint_32 skip = 0; + + png_debug(1, "in png_handle_tEXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + if (length > 65535U) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "too large to fit in memory"); + return; + } +#endif + + buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); + + if (buffer == NULL) + { + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, skip) != 0) + return; + + key = (png_charp)buffer; + key[length] = 0; + + for (text = key; *text; text++) + /* Empty loop to find end of key */ ; + + if (text != key + length) + text++; + + text_info.compression = PNG_TEXT_COMPRESSION_NONE; + text_info.key = key; + text_info.lang = NULL; + text_info.lang_key = NULL; + text_info.itxt_length = 0; + text_info.text = text; + text_info.text_length = strlen(text); + + if (png_set_text_2(png_ptr, info_ptr, &text_info, 1) != 0) + png_warning(png_ptr, "Insufficient memory to process text chunk"); +} +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_const_charp errmsg = NULL; + png_bytep buffer; + png_uint_32 keyword_length; + + png_debug(1, "in png_handle_zTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + + buffer = png_read_buffer(png_ptr, length, 2/*silent*/); + + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* TODO: also check that the keyword contents match the spec! */ + for (keyword_length = 0; + keyword_length < length && buffer[keyword_length] != 0; + ++keyword_length) + /* Empty loop to find end of name */ ; + + if (keyword_length > 79 || keyword_length < 1) + errmsg = "bad keyword"; + + /* zTXt must have some LZ data after the keyword, although it may expand to + * zero bytes; we need a '\0' at the end of the keyword, the compression type + * then the LZ data: + */ + else if (keyword_length + 3 > length) + errmsg = "truncated"; + + else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE) + errmsg = "unknown compression type"; + + else + { + png_alloc_size_t uncompressed_length = PNG_SIZE_MAX; + + /* TODO: at present png_decompress_chunk imposes a single application + * level memory limit, this should be split to different values for iCCP + * and text chunks. + */ + if (png_decompress_chunk(png_ptr, length, keyword_length+2, + &uncompressed_length, 1/*terminate*/) == Z_STREAM_END) + { + png_text text; + + /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except + * for the extra compression type byte and the fact that it isn't + * necessarily '\0' terminated. + */ + buffer = png_ptr->read_buffer; + buffer[uncompressed_length+(keyword_length+2)] = 0; + + text.compression = PNG_TEXT_COMPRESSION_zTXt; + text.key = (png_charp)buffer; + text.text = (png_charp)(buffer + keyword_length+2); + text.text_length = uncompressed_length; + text.itxt_length = 0; + text.lang = NULL; + text.lang_key = NULL; + + if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0) + errmsg = "insufficient memory"; + } + + else + errmsg = png_ptr->zstream.msg; + } + + if (errmsg != NULL) + png_chunk_benign_error(png_ptr, errmsg); +} +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length) +{ + png_const_charp errmsg = NULL; + png_bytep buffer; + png_uint_32 prefix_length; + + png_debug(1, "in png_handle_iTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + return; + } + } +#endif + + if ((png_ptr->mode & PNG_HAVE_IHDR) == 0) + png_chunk_error(png_ptr, "missing IHDR"); + + if ((png_ptr->mode & PNG_HAVE_IDAT) != 0) + png_ptr->mode |= PNG_AFTER_IDAT; + + buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/); + + if (buffer == NULL) + { + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "out of memory"); + return; + } + + png_crc_read(png_ptr, buffer, length); + + if (png_crc_finish(png_ptr, 0) != 0) + return; + + /* First the keyword. */ + for (prefix_length=0; + prefix_length < length && buffer[prefix_length] != 0; + ++prefix_length) + /* Empty loop */ ; + + /* Perform a basic check on the keyword length here. */ + if (prefix_length > 79 || prefix_length < 1) + errmsg = "bad keyword"; + + /* Expect keyword, compression flag, compression type, language, translated + * keyword (both may be empty but are 0 terminated) then the text, which may + * be empty. + */ + else if (prefix_length + 5 > length) + errmsg = "truncated"; + + else if (buffer[prefix_length+1] == 0 || + (buffer[prefix_length+1] == 1 && + buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE)) + { + int compressed = buffer[prefix_length+1] != 0; + png_uint_32 language_offset, translated_keyword_offset; + png_alloc_size_t uncompressed_length = 0; + + /* Now the language tag */ + prefix_length += 3; + language_offset = prefix_length; + + for (; prefix_length < length && buffer[prefix_length] != 0; + ++prefix_length) + /* Empty loop */ ; + + /* WARNING: the length may be invalid here, this is checked below. */ + translated_keyword_offset = ++prefix_length; + + for (; prefix_length < length && buffer[prefix_length] != 0; + ++prefix_length) + /* Empty loop */ ; + + /* prefix_length should now be at the trailing '\0' of the translated + * keyword, but it may already be over the end. None of this arithmetic + * can overflow because chunks are at most 2^31 bytes long, but on 16-bit + * systems the available allocation may overflow. + */ + ++prefix_length; + + if (compressed == 0 && prefix_length <= length) + uncompressed_length = length - prefix_length; + + else if (compressed != 0 && prefix_length < length) + { + uncompressed_length = PNG_SIZE_MAX; + + /* TODO: at present png_decompress_chunk imposes a single application + * level memory limit, this should be split to different values for + * iCCP and text chunks. + */ + if (png_decompress_chunk(png_ptr, length, prefix_length, + &uncompressed_length, 1/*terminate*/) == Z_STREAM_END) + buffer = png_ptr->read_buffer; + + else + errmsg = png_ptr->zstream.msg; + } + + else + errmsg = "truncated"; + + if (errmsg == NULL) + { + png_text text; + + buffer[uncompressed_length+prefix_length] = 0; + + if (compressed == 0) + text.compression = PNG_ITXT_COMPRESSION_NONE; + + else + text.compression = PNG_ITXT_COMPRESSION_zTXt; + + text.key = (png_charp)buffer; + text.lang = (png_charp)buffer + language_offset; + text.lang_key = (png_charp)buffer + translated_keyword_offset; + text.text = (png_charp)buffer + prefix_length; + text.text_length = 0; + text.itxt_length = uncompressed_length; + + if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0) + errmsg = "insufficient memory"; + } + } + + else + errmsg = "bad compression info"; + + if (errmsg != NULL) + png_chunk_benign_error(png_ptr, errmsg); +} +#endif + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED +/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */ +static int +png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length) +{ + png_alloc_size_t limit = PNG_SIZE_MAX; + + if (png_ptr->unknown_chunk.data != NULL) + { + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + } + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_malloc_max > 0 && + png_ptr->user_chunk_malloc_max < limit) + limit = png_ptr->user_chunk_malloc_max; + +# elif PNG_USER_CHUNK_MALLOC_MAX > 0 + if (PNG_USER_CHUNK_MALLOC_MAX < limit) + limit = PNG_USER_CHUNK_MALLOC_MAX; +# endif + + if (length <= limit) + { + PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name); + /* The following is safe because of the PNG_SIZE_MAX init above */ + png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/; + /* 'mode' is a flag array, only the bottom four bits matter here */ + png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/; + + if (length == 0) + png_ptr->unknown_chunk.data = NULL; + + else + { + /* Do a 'warn' here - it is handled below. */ + png_ptr->unknown_chunk.data = png_voidcast(png_bytep, + png_malloc_warn(png_ptr, length)); + } + } + + if (png_ptr->unknown_chunk.data == NULL && length > 0) + { + /* This is benign because we clean up correctly */ + png_crc_finish(png_ptr, length); + png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits"); + return 0; + } + + else + { + if (length > 0) + png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length); + png_crc_finish(png_ptr, 0); + return 1; + } +} +#endif /* READ_UNKNOWN_CHUNKS */ + +/* Handle an unknown, or known but disabled, chunk */ +void /* PRIVATE */ +png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr, + png_uint_32 length, int keep) +{ + int handled = 0; /* the chunk was handled */ + + png_debug(1, "in png_handle_unknown"); + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing + * the bug which meant that setting a non-default behavior for a specific + * chunk would be ignored (the default was always used unless a user + * callback was installed). + * + * 'keep' is the value from the png_chunk_unknown_handling, the setting for + * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it + * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here. + * This is just an optimization to avoid multiple calls to the lookup + * function. + */ +# ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name); +# endif +# endif + + /* One of the following methods will read the chunk or skip it (at least one + * of these is always defined because this is the only way to switch on + * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) + */ +# ifdef PNG_READ_USER_CHUNKS_SUPPORTED + /* The user callback takes precedence over the chunk keep value, but the + * keep value is still required to validate a save of a critical chunk. + */ + if (png_ptr->read_user_chunk_fn != NULL) + { + if (png_cache_unknown_chunk(png_ptr, length) != 0) + { + /* Callback to user unknown chunk handler */ + int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr, + &png_ptr->unknown_chunk); + + /* ret is: + * negative: An error occurred; png_chunk_error will be called. + * zero: The chunk was not handled, the chunk will be discarded + * unless png_set_keep_unknown_chunks has been used to set + * a 'keep' behavior for this particular chunk, in which + * case that will be used. A critical chunk will cause an + * error at this point unless it is to be saved. + * positive: The chunk was handled, libpng will ignore/discard it. + */ + if (ret < 0) + png_chunk_error(png_ptr, "error in user chunk"); + + else if (ret == 0) + { + /* If the keep value is 'default' or 'never' override it, but + * still error out on critical chunks unless the keep value is + * 'always' While this is weird it is the behavior in 1.4.12. + * A possible improvement would be to obey the value set for the + * chunk, but this would be an API change that would probably + * damage some applications. + * + * The png_app_warning below catches the case that matters, where + * the application has not set specific save or ignore for this + * chunk or global save or ignore. + */ + if (keep < PNG_HANDLE_CHUNK_IF_SAFE) + { +# ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE) + { + png_chunk_warning(png_ptr, "Saving unknown chunk:"); + png_app_warning(png_ptr, + "forcing save of an unhandled chunk;" + " please call png_set_keep_unknown_chunks"); + /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */ + } +# endif + keep = PNG_HANDLE_CHUNK_IF_SAFE; + } + } + + else /* chunk was handled */ + { + handled = 1; + /* Critical chunks can be safely discarded at this point. */ + keep = PNG_HANDLE_CHUNK_NEVER; + } + } + + else + keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */ + } + + else + /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */ +# endif /* READ_USER_CHUNKS */ + +# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED + { + /* keep is currently just the per-chunk setting, if there was no + * setting change it to the global default now (not that this may + * still be AS_DEFAULT) then obtain the cache of the chunk if required, + * if not simply skip the chunk. + */ + if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT) + keep = png_ptr->unknown_default; + + if (keep == PNG_HANDLE_CHUNK_ALWAYS || + (keep == PNG_HANDLE_CHUNK_IF_SAFE && + PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) + { + if (png_cache_unknown_chunk(png_ptr, length) == 0) + keep = PNG_HANDLE_CHUNK_NEVER; + } + + else + png_crc_finish(png_ptr, length); + } +# else +# ifndef PNG_READ_USER_CHUNKS_SUPPORTED +# error no method to support READ_UNKNOWN_CHUNKS +# endif + + { + /* If here there is no read callback pointer set and no support is + * compiled in to just save the unknown chunks, so simply skip this + * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then + * the app has erroneously asked for unknown chunk saving when there + * is no support. + */ + if (keep > PNG_HANDLE_CHUNK_NEVER) + png_app_error(png_ptr, "no unknown chunk support available"); + + png_crc_finish(png_ptr, length); + } +# endif + +# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + /* Now store the chunk in the chunk list if appropriate, and if the limits + * permit it. + */ + if (keep == PNG_HANDLE_CHUNK_ALWAYS || + (keep == PNG_HANDLE_CHUNK_IF_SAFE && + PNG_CHUNK_ANCILLARY(png_ptr->chunk_name))) + { +# ifdef PNG_USER_LIMITS_SUPPORTED + switch (png_ptr->user_chunk_cache_max) + { + case 2: + png_ptr->user_chunk_cache_max = 1; + png_chunk_benign_error(png_ptr, "no space in chunk cache"); + /* FALL THROUGH */ + case 1: + /* NOTE: prior to 1.6.0 this case resulted in an unknown critical + * chunk being skipped, now there will be a hard error below. + */ + break; + + default: /* not at limit */ + --(png_ptr->user_chunk_cache_max); + /* FALL THROUGH */ + case 0: /* no limit */ +# endif /* USER_LIMITS */ + /* Here when the limit isn't reached or when limits are compiled + * out; store the chunk. + */ + png_set_unknown_chunks(png_ptr, info_ptr, + &png_ptr->unknown_chunk, 1); + handled = 1; +# ifdef PNG_USER_LIMITS_SUPPORTED + break; + } +# endif + } +# else /* no store support: the chunk must be handled by the user callback */ + PNG_UNUSED(info_ptr) +# endif + + /* Regardless of the error handling below the cached data (if any) can be + * freed now. Notice that the data is not freed if there is a png_error, but + * it will be freed by destroy_read_struct. + */ + if (png_ptr->unknown_chunk.data != NULL) + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + +#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */ + /* There is no support to read an unknown chunk, so just skip it. */ + png_crc_finish(png_ptr, length); + PNG_UNUSED(info_ptr) + PNG_UNUSED(keep) +#endif /* !READ_UNKNOWN_CHUNKS */ + + /* Check for unhandled critical chunks */ + if (handled == 0 && PNG_CHUNK_CRITICAL(png_ptr->chunk_name)) + png_chunk_error(png_ptr, "unhandled critical chunk"); +} + +/* This function is called to verify that a chunk name is valid. + * This function can't have the "critical chunk check" incorporated + * into it, since in the future we will need to be able to call user + * functions to handle unknown critical chunks after we check that + * the chunk name itself is valid. + */ + +/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is: + * + * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) + */ + +void /* PRIVATE */ +png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name) +{ + int i; + + png_debug(1, "in png_check_chunk_name"); + + for (i=1; i<=4; ++i) + { + int c = chunk_name & 0xff; + + if (c < 65 || c > 122 || (c > 90 && c < 97)) + png_chunk_error(png_ptr, "invalid chunk type"); + + chunk_name >>= 8; + } +} + +/* Combines the row recently read in with the existing pixels in the row. This + * routine takes care of alpha and transparency if requested. This routine also + * handles the two methods of progressive display of interlaced images, + * depending on the 'display' value; if 'display' is true then the whole row + * (dp) is filled from the start by replicating the available pixels. If + * 'display' is false only those pixels present in the pass are filled in. + */ +void /* PRIVATE */ +png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display) +{ + unsigned int pixel_depth = png_ptr->transformed_pixel_depth; + png_const_bytep sp = png_ptr->row_buf + 1; + png_alloc_size_t row_width = png_ptr->width; + unsigned int pass = png_ptr->pass; + png_bytep end_ptr = 0; + png_byte end_byte = 0; + unsigned int end_mask; + + png_debug(1, "in png_combine_row"); + + /* Added in 1.5.6: it should not be possible to enter this routine until at + * least one row has been read from the PNG data and transformed. + */ + if (pixel_depth == 0) + png_error(png_ptr, "internal row logic error"); + + /* Added in 1.5.4: the pixel depth should match the information returned by + * any call to png_read_update_info at this point. Do not continue if we got + * this wrong. + */ + if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes != + PNG_ROWBYTES(pixel_depth, row_width)) + png_error(png_ptr, "internal row size calculation error"); + + /* Don't expect this to ever happen: */ + if (row_width == 0) + png_error(png_ptr, "internal row width error"); + + /* Preserve the last byte in cases where only part of it will be overwritten, + * the multiply below may overflow, we don't care because ANSI-C guarantees + * we get the low bits. + */ + end_mask = (pixel_depth * row_width) & 7; + if (end_mask != 0) + { + /* end_ptr == NULL is a flag to say do nothing */ + end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1; + end_byte = *end_ptr; +# ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + /* little-endian byte */ + end_mask = 0xff << end_mask; + + else /* big-endian byte */ +# endif + end_mask = 0xff >> end_mask; + /* end_mask is now the bits to *keep* from the destination row */ + } + + /* For non-interlaced images this reduces to a memcpy(). A memcpy() + * will also happen if interlacing isn't supported or if the application + * does not call png_set_interlace_handling(). In the latter cases the + * caller just gets a sequence of the unexpanded rows from each interlace + * pass. + */ +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0 && + pass < 6 && (display == 0 || + /* The following copies everything for 'display' on passes 0, 2 and 4. */ + (display == 1 && (pass & 1) != 0))) + { + /* Narrow images may have no bits in a pass; the caller should handle + * this, but this test is cheap: + */ + if (row_width <= PNG_PASS_START_COL(pass)) + return; + + if (pixel_depth < 8) + { + /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit + * into 32 bits, then a single loop over the bytes using the four byte + * values in the 32-bit mask can be used. For the 'display' option the + * expanded mask may also not require any masking within a byte. To + * make this work the PACKSWAP option must be taken into account - it + * simply requires the pixels to be reversed in each byte. + * + * The 'regular' case requires a mask for each of the first 6 passes, + * the 'display' case does a copy for the even passes in the range + * 0..6. This has already been handled in the test above. + * + * The masks are arranged as four bytes with the first byte to use in + * the lowest bits (little-endian) regardless of the order (PACKSWAP or + * not) of the pixels in each byte. + * + * NOTE: the whole of this logic depends on the caller of this function + * only calling it on rows appropriate to the pass. This function only + * understands the 'x' logic; the 'y' logic is handled by the caller. + * + * The following defines allow generation of compile time constant bit + * masks for each pixel depth and each possibility of swapped or not + * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index, + * is in the range 0..7; and the result is 1 if the pixel is to be + * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B' + * for the block method. + * + * With some compilers a compile time expression of the general form: + * + * (shift >= 32) ? (a >> (shift-32)) : (b >> shift) + * + * Produces warnings with values of 'shift' in the range 33 to 63 + * because the right hand side of the ?: expression is evaluated by + * the compiler even though it isn't used. Microsoft Visual C (various + * versions) and the Intel C compiler are known to do this. To avoid + * this the following macros are used in 1.5.6. This is a temporary + * solution to avoid destabilizing the code during the release process. + */ +# if PNG_USE_COMPILE_TIME_MASKS +# define PNG_LSR(x,s) ((x)>>((s) & 0x1f)) +# define PNG_LSL(x,s) ((x)<<((s) & 0x1f)) +# else +# define PNG_LSR(x,s) ((x)>>(s)) +# define PNG_LSL(x,s) ((x)<<(s)) +# endif +# define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1) +# define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\ + PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1) + + /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is + * little endian - the first pixel is at bit 0 - however the extra + * parameter 's' can be set to cause the mask position to be swapped + * within each byte, to match the PNG format. This is done by XOR of + * the shift with 7, 6 or 4 for bit depths 1, 2 and 4. + */ +# define PIXEL_MASK(p,x,d,s) \ + (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0)))) + + /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask. + */ +# define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) +# define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0) + + /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp + * cases the result needs replicating, for the 4-bpp case the above + * generates a full 32 bits. + */ +# define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1))) + +# define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\ + S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\ + S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d) + +# define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\ + B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\ + B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d) + +#if PNG_USE_COMPILE_TIME_MASKS + /* Utility macros to construct all the masks for a depth/swap + * combination. The 's' parameter says whether the format is PNG + * (big endian bytes) or not. Only the three odd-numbered passes are + * required for the display/block algorithm. + */ +# define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\ + S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) } + +# define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) } + +# define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2)) + + /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and + * then pass: + */ + static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] = + { + /* Little-endian byte masks for PACKSWAP */ + { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) } + }; + + /* display_mask has only three entries for the odd passes, so index by + * pass>>1. + */ + static PNG_CONST png_uint_32 display_mask[2][3][3] = + { + /* Little-endian byte masks for PACKSWAP */ + { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) }, + /* Normal (big-endian byte) masks - PNG format */ + { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) } + }; + +# define MASK(pass,depth,display,png)\ + ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\ + row_mask[png][DEPTH_INDEX(depth)][pass]) + +#else /* !PNG_USE_COMPILE_TIME_MASKS */ + /* This is the runtime alternative: it seems unlikely that this will + * ever be either smaller or faster than the compile time approach. + */ +# define MASK(pass,depth,display,png)\ + ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png)) +#endif /* !USE_COMPILE_TIME_MASKS */ + + /* Use the appropriate mask to copy the required bits. In some cases + * the byte mask will be 0 or 0xff; optimize these cases. row_width is + * the number of pixels, but the code copies bytes, so it is necessary + * to special case the end. + */ + png_uint_32 pixels_per_byte = 8 / pixel_depth; + png_uint_32 mask; + +# ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + mask = MASK(pass, pixel_depth, display, 0); + + else +# endif + mask = MASK(pass, pixel_depth, display, 1); + + for (;;) + { + png_uint_32 m; + + /* It doesn't matter in the following if png_uint_32 has more than + * 32 bits because the high bits always match those in m<<24; it is, + * however, essential to use OR here, not +, because of this. + */ + m = mask; + mask = (m >> 8) | (m << 24); /* rotate right to good compilers */ + m &= 0xff; + + if (m != 0) /* something to copy */ + { + if (m != 0xff) + *dp = (png_byte)((*dp & ~m) | (*sp & m)); + else + *dp = *sp; + } + + /* NOTE: this may overwrite the last byte with garbage if the image + * is not an exact number of bytes wide; libpng has always done + * this. + */ + if (row_width <= pixels_per_byte) + break; /* May need to restore part of the last byte */ + + row_width -= pixels_per_byte; + ++dp; + ++sp; + } + } + + else /* pixel_depth >= 8 */ + { + unsigned int bytes_to_copy, bytes_to_jump; + + /* Validate the depth - it must be a multiple of 8 */ + if (pixel_depth & 7) + png_error(png_ptr, "invalid user transform pixel depth"); + + pixel_depth >>= 3; /* now in bytes */ + row_width *= pixel_depth; + + /* Regardless of pass number the Adam 7 interlace always results in a + * fixed number of pixels to copy then to skip. There may be a + * different number of pixels to skip at the start though. + */ + { + unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth; + + row_width -= offset; + dp += offset; + sp += offset; + } + + /* Work out the bytes to copy. */ + if (display != 0) + { + /* When doing the 'block' algorithm the pixel in the pass gets + * replicated to adjacent pixels. This is why the even (0,2,4,6) + * passes are skipped above - the entire expanded row is copied. + */ + bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth; + + /* But don't allow this number to exceed the actual row width. */ + if (bytes_to_copy > row_width) + bytes_to_copy = (unsigned int)/*SAFE*/row_width; + } + + else /* normal row; Adam7 only ever gives us one pixel to copy. */ + bytes_to_copy = pixel_depth; + + /* In Adam7 there is a constant offset between where the pixels go. */ + bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth; + + /* And simply copy these bytes. Some optimization is possible here, + * depending on the value of 'bytes_to_copy'. Special case the low + * byte counts, which we know to be frequent. + * + * Notice that these cases all 'return' rather than 'break' - this + * avoids an unnecessary test on whether to restore the last byte + * below. + */ + switch (bytes_to_copy) + { + case 1: + for (;;) + { + *dp = *sp; + + if (row_width <= bytes_to_jump) + return; + + dp += bytes_to_jump; + sp += bytes_to_jump; + row_width -= bytes_to_jump; + } + + case 2: + /* There is a possibility of a partial copy at the end here; this + * slows the code down somewhat. + */ + do + { + dp[0] = sp[0], dp[1] = sp[1]; + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + } + while (row_width > 1); + + /* And there can only be one byte left at this point: */ + *dp = *sp; + return; + + case 3: + /* This can only be the RGB case, so each copy is exactly one + * pixel and it is not necessary to check for a partial copy. + */ + for (;;) + { + dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2]; + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + } + + default: +#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE + /* Check for double byte alignment and, if possible, use a + * 16-bit copy. Don't attempt this for narrow images - ones that + * are less than an interlace panel wide. Don't attempt it for + * wide bytes_to_copy either - use the memcpy there. + */ + if (bytes_to_copy < 16 /*else use memcpy*/ && + png_isaligned(dp, png_uint_16) && + png_isaligned(sp, png_uint_16) && + bytes_to_copy % (sizeof (png_uint_16)) == 0 && + bytes_to_jump % (sizeof (png_uint_16)) == 0) + { + /* Everything is aligned for png_uint_16 copies, but try for + * png_uint_32 first. + */ + if (png_isaligned(dp, png_uint_32) != 0 && + png_isaligned(sp, png_uint_32) != 0 && + bytes_to_copy % (sizeof (png_uint_32)) == 0 && + bytes_to_jump % (sizeof (png_uint_32)) == 0) + { + png_uint_32p dp32 = png_aligncast(png_uint_32p,dp); + png_const_uint_32p sp32 = png_aligncastconst( + png_const_uint_32p, sp); + size_t skip = (bytes_to_jump-bytes_to_copy) / + (sizeof (png_uint_32)); + + do + { + size_t c = bytes_to_copy; + do + { + *dp32++ = *sp32++; + c -= (sizeof (png_uint_32)); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp32 += skip; + sp32 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* Get to here when the row_width truncates the final copy. + * There will be 1-3 bytes left to copy, so don't try the + * 16-bit loop below. + */ + dp = (png_bytep)dp32; + sp = (png_const_bytep)sp32; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + + /* Else do it in 16-bit quantities, but only if the size is + * not too large. + */ + else + { + png_uint_16p dp16 = png_aligncast(png_uint_16p, dp); + png_const_uint_16p sp16 = png_aligncastconst( + png_const_uint_16p, sp); + size_t skip = (bytes_to_jump-bytes_to_copy) / + (sizeof (png_uint_16)); + + do + { + size_t c = bytes_to_copy; + do + { + *dp16++ = *sp16++; + c -= (sizeof (png_uint_16)); + } + while (c > 0); + + if (row_width <= bytes_to_jump) + return; + + dp16 += skip; + sp16 += skip; + row_width -= bytes_to_jump; + } + while (bytes_to_copy <= row_width); + + /* End of row - 1 byte left, bytes_to_copy > row_width: */ + dp = (png_bytep)dp16; + sp = (png_const_bytep)sp16; + do + *dp++ = *sp++; + while (--row_width > 0); + return; + } + } +#endif /* ALIGN_TYPE code */ + + /* The true default - use a memcpy: */ + for (;;) + { + memcpy(dp, sp, bytes_to_copy); + + if (row_width <= bytes_to_jump) + return; + + sp += bytes_to_jump; + dp += bytes_to_jump; + row_width -= bytes_to_jump; + if (bytes_to_copy > row_width) + bytes_to_copy = (unsigned int)/*SAFE*/row_width; + } + } + + /* NOT REACHED*/ + } /* pixel_depth >= 8 */ + + /* Here if pixel_depth < 8 to check 'end_ptr' below. */ + } + else +#endif /* READ_INTERLACING */ + + /* If here then the switch above wasn't used so just memcpy the whole row + * from the temporary row buffer (notice that this overwrites the end of the + * destination row if it is a partial byte.) + */ + memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width)); + + /* Restore the overwritten bits from the last byte if necessary. */ + if (end_ptr != NULL) + *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask)); +} + +#ifdef PNG_READ_INTERLACING_SUPPORTED +void /* PRIVATE */ +png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, + png_uint_32 transformations /* Because these may affect the byte layout */) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + /* Offset to next interlace block */ + static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_read_interlace"); + if (row != NULL && row_info != NULL) + { + png_uint_32 final_width; + + final_width = row_info->width * png_pass_inc[pass]; + + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); + png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); + int sshift, dshift; + int s_start, s_end, s_inc; + int jstop = png_pass_inc[pass]; + png_byte v; + png_uint_32 i; + int j; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((transformations & PNG_PACKSWAP) != 0) + { + sshift = (int)((row_info->width + 7) & 0x07); + dshift = (int)((final_width + 7) & 0x07); + s_start = 7; + s_end = 0; + s_inc = -1; + } + + else +#endif + { + sshift = 7 - (int)((row_info->width + 7) & 0x07); + dshift = 7 - (int)((final_width + 7) & 0x07); + s_start = 0; + s_end = 7; + s_inc = 1; + } + + for (i = 0; i < row_info->width; i++) + { + v = (png_byte)((*sp >> sshift) & 0x01); + for (j = 0; j < jstop; j++) + { + unsigned int tmp = *dp & (0x7f7f >> (7 - dshift)); + tmp |= v << dshift; + *dp = (png_byte)(tmp & 0xff); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift += s_inc; + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift += s_inc; + } + break; + } + + case 2: + { + png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); + png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); + int sshift, dshift; + int s_start, s_end, s_inc; + int jstop = png_pass_inc[pass]; + png_uint_32 i; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((transformations & PNG_PACKSWAP) != 0) + { + sshift = (int)(((row_info->width + 3) & 0x03) << 1); + dshift = (int)(((final_width + 3) & 0x03) << 1); + s_start = 6; + s_end = 0; + s_inc = -2; + } + + else +#endif + { + sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1); + dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1); + s_start = 0; + s_end = 6; + s_inc = 2; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v; + int j; + + v = (png_byte)((*sp >> sshift) & 0x03); + for (j = 0; j < jstop; j++) + { + unsigned int tmp = *dp & (0x3f3f >> (6 - dshift)); + tmp |= v << dshift; + *dp = (png_byte)(tmp & 0xff); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift += s_inc; + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift += s_inc; + } + break; + } + + case 4: + { + png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); + png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); + int sshift, dshift; + int s_start, s_end, s_inc; + png_uint_32 i; + int jstop = png_pass_inc[pass]; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if ((transformations & PNG_PACKSWAP) != 0) + { + sshift = (int)(((row_info->width + 1) & 0x01) << 2); + dshift = (int)(((final_width + 1) & 0x01) << 2); + s_start = 4; + s_end = 0; + s_inc = -4; + } + + else +#endif + { + sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2); + dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2); + s_start = 0; + s_end = 4; + s_inc = 4; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v = (png_byte)((*sp >> sshift) & 0x0f); + int j; + + for (j = 0; j < jstop; j++) + { + unsigned int tmp = *dp & (0xf0f >> (4 - dshift)); + tmp |= v << dshift; + *dp = (png_byte)(tmp & 0xff); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift += s_inc; + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift += s_inc; + } + break; + } + + default: + { + png_size_t pixel_bytes = (row_info->pixel_depth >> 3); + + png_bytep sp = row + (png_size_t)(row_info->width - 1) + * pixel_bytes; + + png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; + + int jstop = png_pass_inc[pass]; + png_uint_32 i; + + for (i = 0; i < row_info->width; i++) + { + png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */ + int j; + + memcpy(v, sp, pixel_bytes); + + for (j = 0; j < jstop; j++) + { + memcpy(dp, v, pixel_bytes); + dp -= pixel_bytes; + } + + sp -= pixel_bytes; + } + break; + } + } + + row_info->width = final_width; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); + } +#ifndef PNG_READ_PACKSWAP_SUPPORTED + PNG_UNUSED(transformations) /* Silence compiler warning */ +#endif +} +#endif /* READ_INTERLACING */ + +static void +png_read_filter_row_sub(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_size_t istop = row_info->rowbytes; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp = row + bpp; + + PNG_UNUSED(prev_row) + + for (i = bpp; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff); + rp++; + } +} + +static void +png_read_filter_row_up(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_size_t istop = row_info->rowbytes; + png_bytep rp = row; + png_const_bytep pp = prev_row; + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } +} + +static void +png_read_filter_row_avg(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_size_t i; + png_bytep rp = row; + png_const_bytep pp = prev_row; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_size_t istop = row_info->rowbytes - bpp; + + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); + + rp++; + } + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff); + + rp++; + } +} + +static void +png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + png_bytep rp_end = row + row_info->rowbytes; + int a, c; + + /* First pixel/byte */ + c = *prev_row++; + a = *row + c; + *row++ = (png_byte)a; + + /* Remainder */ + while (row < rp_end) + { + int b, pa, pb, pc, p; + + a &= 0xff; /* From previous iteration or start */ + b = *prev_row++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + /* Find the best predictor, the least of pa, pb, pc favoring the earlier + * ones in the case of a tie. + */ + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + /* Calculate the current pixel in a, and move the previous row pixel to c + * for the next time round the loop + */ + c = b; + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row, + png_const_bytep prev_row) +{ + int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp_end = row + bpp; + + /* Process the first pixel in the row completely (this is the same as 'up' + * because there is only one candidate predictor for the first row). + */ + while (row < rp_end) + { + int a = *row + *prev_row++; + *row++ = (png_byte)a; + } + + /* Remainder */ + rp_end += row_info->rowbytes - bpp; + + while (row < rp_end) + { + int a, b, c, pa, pb, pc, p; + + c = *(prev_row - bpp); + a = *(row - bpp); + b = *prev_row++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + if (pb < pa) pa = pb, a = b; + if (pc < pa) a = c; + + a += *row; + *row++ = (png_byte)a; + } +} + +static void +png_init_filter_functions(png_structrp pp) + /* This function is called once for every PNG image (except for PNG images + * that only use PNG_FILTER_VALUE_NONE for all rows) to set the + * implementations required to reverse the filtering of PNG rows. Reversing + * the filter is the first transformation performed on the row data. It is + * performed in place, therefore an implementation can be selected based on + * the image pixel format. If the implementation depends on image width then + * take care to ensure that it works correctly if the image is interlaced - + * interlacing causes the actual row width to vary. + */ +{ + unsigned int bpp = (pp->pixel_depth + 7) >> 3; + + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub; + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg; + if (bpp == 1) + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_1byte_pixel; + else + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth_multibyte_pixel; + +#ifdef PNG_FILTER_OPTIMIZATIONS + /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to + * call to install hardware optimizations for the above functions; simply + * replace whatever elements of the pp->read_filter[] array with a hardware + * specific (or, for that matter, generic) optimization. + * + * To see an example of this examine what configure.ac does when + * --enable-arm-neon is specified on the command line. + */ + PNG_FILTER_OPTIMIZATIONS(pp, bpp); +#endif +} + +void /* PRIVATE */ +png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row, + png_const_bytep prev_row, int filter) +{ + /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define + * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic + * implementations. See png_init_filter_functions above. + */ + if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST) + { + if (pp->read_filter[0] == NULL) + png_init_filter_functions(pp); + + pp->read_filter[filter-1](row_info, row, prev_row); + } +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +void /* PRIVATE */ +png_read_IDAT_data(png_structrp png_ptr, png_bytep output, + png_alloc_size_t avail_out) +{ + /* Loop reading IDATs and decompressing the result into output[avail_out] */ + png_ptr->zstream.next_out = output; + png_ptr->zstream.avail_out = 0; /* safety: set below */ + + if (output == NULL) + avail_out = 0; + + do + { + int ret; + png_byte tmpbuf[PNG_INFLATE_BUF_SIZE]; + + if (png_ptr->zstream.avail_in == 0) + { + uInt avail_in; + png_bytep buffer; + + while (png_ptr->idat_size == 0) + { + png_crc_finish(png_ptr, 0); + + png_ptr->idat_size = png_read_chunk_header(png_ptr); + /* This is an error even in the 'check' case because the code just + * consumed a non-IDAT header. + */ + if (png_ptr->chunk_name != png_IDAT) + png_error(png_ptr, "Not enough image data"); + } + + avail_in = png_ptr->IDAT_read_size; + + if (avail_in > png_ptr->idat_size) + avail_in = (uInt)png_ptr->idat_size; + + /* A PNG with a gradually increasing IDAT size will defeat this attempt + * to minimize memory usage by causing lots of re-allocs, but + * realistically doing IDAT_read_size re-allocs is not likely to be a + * big problem. + */ + buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/); + + png_crc_read(png_ptr, buffer, avail_in); + png_ptr->idat_size -= avail_in; + + png_ptr->zstream.next_in = buffer; + png_ptr->zstream.avail_in = avail_in; + } + + /* And set up the output side. */ + if (output != NULL) /* standard read */ + { + uInt out = ZLIB_IO_MAX; + + if (out > avail_out) + out = (uInt)avail_out; + + avail_out -= out; + png_ptr->zstream.avail_out = out; + } + + else /* after last row, checking for end */ + { + png_ptr->zstream.next_out = tmpbuf; + png_ptr->zstream.avail_out = (sizeof tmpbuf); + } + + /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the + * process. If the LZ stream is truncated the sequential reader will + * terminally damage the stream, above, by reading the chunk header of the + * following chunk (it then exits with png_error). + * + * TODO: deal more elegantly with truncated IDAT lists. + */ + ret = PNG_INFLATE(png_ptr, Z_NO_FLUSH); + + /* Take the unconsumed output back. */ + if (output != NULL) + avail_out += png_ptr->zstream.avail_out; + + else /* avail_out counts the extra bytes */ + avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out; + + png_ptr->zstream.avail_out = 0; + + if (ret == Z_STREAM_END) + { + /* Do this for safety; we won't read any more into this row. */ + png_ptr->zstream.next_out = NULL; + + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + + if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0) + png_chunk_benign_error(png_ptr, "Extra compressed data"); + break; + } + + if (ret != Z_OK) + { + png_zstream_error(png_ptr, ret); + + if (output != NULL) + png_chunk_error(png_ptr, png_ptr->zstream.msg); + + else /* checking */ + { + png_chunk_benign_error(png_ptr, png_ptr->zstream.msg); + return; + } + } + } while (avail_out > 0); + + if (avail_out > 0) + { + /* The stream ended before the image; this is the same as too few IDATs so + * should be handled the same way. + */ + if (output != NULL) + png_error(png_ptr, "Not enough image data"); + + else /* the deflate stream contained extra data */ + png_chunk_benign_error(png_ptr, "Too much image data"); + } +} + +void /* PRIVATE */ +png_read_finish_IDAT(png_structrp png_ptr) +{ + /* We don't need any more data and the stream should have ended, however the + * LZ end code may actually not have been processed. In this case we must + * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk + * may still remain to be consumed. + */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + { + /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in + * the compressed stream, but the stream may be damaged too, so even after + * this call we may need to terminate the zstream ownership. + */ + png_read_IDAT_data(png_ptr, NULL, 0); + png_ptr->zstream.next_out = NULL; /* safety */ + + /* Now clear everything out for safety; the following may not have been + * done. + */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0) + { + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; + } + } + + /* If the zstream has not been released do it now *and* terminate the reading + * of the final IDAT chunk. + */ + if (png_ptr->zowner == png_IDAT) + { + /* Always do this; the pointers otherwise point into the read buffer. */ + png_ptr->zstream.next_in = NULL; + png_ptr->zstream.avail_in = 0; + + /* Now we no longer own the zstream. */ + png_ptr->zowner = 0; + + /* The slightly weird semantics of the sequential IDAT reading is that we + * are always in or at the end of an IDAT chunk, so we always need to do a + * crc_finish here. If idat_size is non-zero we also need to read the + * spurious bytes at the end of the chunk now. + */ + (void)png_crc_finish(png_ptr, png_ptr->idat_size); + } +} + +void /* PRIVATE */ +png_read_finish_row(png_structrp png_ptr) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + + png_debug(1, "in png_read_finish_row"); + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + + if (png_ptr->interlaced != 0) + { + png_ptr->row_number = 0; + + /* TO DO: don't do this if prev_row isn't needed (requires + * read-ahead of the next row's filter byte. + */ + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + do + { + png_ptr->pass++; + + if (png_ptr->pass >= 7) + break; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + if ((png_ptr->transformations & PNG_INTERLACE) == 0) + { + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + } + + else /* if (png_ptr->transformations & PNG_INTERLACE) */ + break; /* libpng deinterlacing sees every row */ + + } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0); + + if (png_ptr->pass < 7) + return; + } + + /* Here after at the end of the last row of the last pass. */ + png_read_finish_IDAT(png_ptr); +} +#endif /* SEQUENTIAL_READ */ + +void /* PRIVATE */ +png_read_start_row(png_structrp png_ptr) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; + + int max_pixel_depth; + png_size_t row_bytes; + + png_debug(1, "in png_read_start_row"); + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + png_init_read_transformations(png_ptr); +#endif + if (png_ptr->interlaced != 0) + { + if ((png_ptr->transformations & PNG_INTERLACE) == 0) + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + + else + png_ptr->num_rows = png_ptr->height; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + } + + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->iwidth = png_ptr->width; + } + + max_pixel_depth = png_ptr->pixel_depth; + + /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler set of + * calculations to calculate the final pixel depth, then + * png_do_read_transforms actually does the transforms. This means that the + * code which effectively calculates this value is actually repeated in three + * separate places. They must all match. Innocent changes to the order of + * transformations can and will break libpng in a way that causes memory + * overwrites. + * + * TODO: fix this. + */ +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0 && png_ptr->bit_depth < 8) + max_pixel_depth = 8; +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (png_ptr->num_trans != 0) + max_pixel_depth = 32; + + else + max_pixel_depth = 24; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth < 8) + max_pixel_depth = 8; + + if (png_ptr->num_trans != 0) + max_pixel_depth *= 2; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + if (png_ptr->num_trans != 0) + { + max_pixel_depth *= 4; + max_pixel_depth /= 3; + } + } + } +#endif + +#ifdef PNG_READ_EXPAND_16_SUPPORTED + if ((png_ptr->transformations & PNG_EXPAND_16) != 0) + { +# ifdef PNG_READ_EXPAND_SUPPORTED + /* In fact it is an error if it isn't supported, but checking is + * the safe way. + */ + if ((png_ptr->transformations & PNG_EXPAND) != 0) + { + if (png_ptr->bit_depth < 16) + max_pixel_depth *= 2; + } + else +# endif + png_ptr->transformations &= ~PNG_EXPAND_16; + } +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED + if ((png_ptr->transformations & (PNG_FILLER)) != 0) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth <= 8) + max_pixel_depth = 16; + + else + max_pixel_depth = 32; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB || + png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (max_pixel_depth <= 32) + max_pixel_depth = 32; + + else + max_pixel_depth = 64; + } + } +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) + { + if ( +#ifdef PNG_READ_EXPAND_SUPPORTED + (png_ptr->num_trans != 0 && + (png_ptr->transformations & PNG_EXPAND) != 0) || +#endif +#ifdef PNG_READ_FILLER_SUPPORTED + (png_ptr->transformations & (PNG_FILLER)) != 0 || +#endif + png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (max_pixel_depth <= 16) + max_pixel_depth = 32; + + else + max_pixel_depth = 64; + } + + else + { + if (max_pixel_depth <= 8) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 32; + + else + max_pixel_depth = 24; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 64; + + else + max_pixel_depth = 48; + } + } +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ +defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + { + int user_pixel_depth = png_ptr->user_transform_depth * + png_ptr->user_transform_channels; + + if (user_pixel_depth > max_pixel_depth) + max_pixel_depth = user_pixel_depth; + } +#endif + + /* This value is stored in png_struct and double checked in the row read + * code. + */ + png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth; + png_ptr->transformed_pixel_depth = 0; /* calculated on demand */ + + /* Align the width on the next larger 8 pixels. Mainly used + * for interlacing + */ + row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); + /* Calculate the maximum bytes needed, adding a byte and a pixel + * for safety's sake + */ + row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) + + 1 + ((max_pixel_depth + 7) >> 3); + +#ifdef PNG_MAX_MALLOC_64K + if (row_bytes > (png_uint_32)65536L) + png_error(png_ptr, "This image requires a row greater than 64KB"); +#endif + + if (row_bytes + 48 > png_ptr->old_big_row_buf_size) + { + png_free(png_ptr, png_ptr->big_row_buf); + png_free(png_ptr, png_ptr->big_prev_row); + + if (png_ptr->interlaced != 0) + png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, + row_bytes + 48); + + else + png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48); + + png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48); + +#ifdef PNG_ALIGNED_MEMORY_SUPPORTED + /* Use 16-byte aligned memory for row_buf with at least 16 bytes + * of padding before and after row_buf; treat prev_row similarly. + * NOTE: the alignment is to the start of the pixels, one beyond the start + * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this + * was incorrect; the filter byte was aligned, which had the exact + * opposite effect of that intended. + */ + { + png_bytep temp = png_ptr->big_row_buf + 32; + int extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->row_buf = temp - extra - 1/*filter byte*/; + + temp = png_ptr->big_prev_row + 32; + extra = (int)((temp - (png_bytep)0) & 0x0f); + png_ptr->prev_row = temp - extra - 1/*filter byte*/; + } + +#else + /* Use 31 bytes of padding before and 17 bytes after row_buf. */ + png_ptr->row_buf = png_ptr->big_row_buf + 31; + png_ptr->prev_row = png_ptr->big_prev_row + 31; +#endif + png_ptr->old_big_row_buf_size = row_bytes + 48; + } + +#ifdef PNG_MAX_MALLOC_64K + if (png_ptr->rowbytes > 65535) + png_error(png_ptr, "This image requires a row greater than 64KB"); + +#endif + if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) + png_error(png_ptr, "Row has too many bytes to allocate in memory"); + + memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + png_debug1(3, "width = %u,", png_ptr->width); + png_debug1(3, "height = %u,", png_ptr->height); + png_debug1(3, "iwidth = %u,", png_ptr->iwidth); + png_debug1(3, "num_rows = %u,", png_ptr->num_rows); + png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes); + png_debug1(3, "irowbytes = %lu", + (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); + + /* The sequential reader needs a buffer for IDAT, but the progressive reader + * does not, so free the read buffer now regardless; the sequential reader + * reallocates it on demand. + */ + if (png_ptr->read_buffer != 0) + { + png_bytep buffer = png_ptr->read_buffer; + + png_ptr->read_buffer_size = 0; + png_ptr->read_buffer = NULL; + png_free(png_ptr, buffer); + } + + /* Finally claim the zstream for the inflate of the IDAT data, use the bits + * value from the stream (note that this will result in a fatal error if the + * IDAT stream has a bogus deflate header window_bits value, but this should + * not be happening any longer!) + */ + if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + png_ptr->flags |= PNG_FLAG_ROW_INIT; +} +#endif /* READ */ diff --git a/thirdparty/libpng/pngset.c b/thirdparty/libpng/pngset.c new file mode 100644 index 0000000000..43456b729d --- /dev/null +++ b/thirdparty/libpng/pngset.c @@ -0,0 +1,1733 @@ + +/* pngset.c - storage of image information into info struct + * + * Last changed in libpng 1.6.23 [June 9, 2016] + * Copyright (c) 1998-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * The functions here are used during reads to store data from the file + * into the info struct, and during writes to store application data + * into the info struct for writing into the file. This abstracts the + * info struct and allows us to change the structure in the future. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +#ifdef PNG_bKGD_SUPPORTED +void PNGAPI +png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_color_16p background) +{ + png_debug1(1, "in %s storage function", "bKGD"); + + if (png_ptr == NULL || info_ptr == NULL || background == NULL) + return; + + info_ptr->background = *background; + info_ptr->valid |= PNG_INFO_bKGD; +} +#endif + +#ifdef PNG_cHRM_SUPPORTED +void PNGFAPI +png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr, + png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, + png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, + png_fixed_point blue_x, png_fixed_point blue_y) +{ + png_xy xy; + + png_debug1(1, "in %s storage function", "cHRM fixed"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + xy.redx = red_x; + xy.redy = red_y; + xy.greenx = green_x; + xy.greeny = green_y; + xy.bluex = blue_x; + xy.bluey = blue_y; + xy.whitex = white_x; + xy.whitey = white_y; + + if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy, + 2/* override with app values*/) != 0) + info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; + + png_colorspace_sync_info(png_ptr, info_ptr); +} + +void PNGFAPI +png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr, + png_fixed_point int_red_X, png_fixed_point int_red_Y, + png_fixed_point int_red_Z, png_fixed_point int_green_X, + png_fixed_point int_green_Y, png_fixed_point int_green_Z, + png_fixed_point int_blue_X, png_fixed_point int_blue_Y, + png_fixed_point int_blue_Z) +{ + png_XYZ XYZ; + + png_debug1(1, "in %s storage function", "cHRM XYZ fixed"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + XYZ.red_X = int_red_X; + XYZ.red_Y = int_red_Y; + XYZ.red_Z = int_red_Z; + XYZ.green_X = int_green_X; + XYZ.green_Y = int_green_Y; + XYZ.green_Z = int_green_Z; + XYZ.blue_X = int_blue_X; + XYZ.blue_Y = int_blue_Y; + XYZ.blue_Z = int_blue_Z; + + if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace, + &XYZ, 2) != 0) + info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM; + + png_colorspace_sync_info(png_ptr, info_ptr); +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, + double white_x, double white_y, double red_x, double red_y, + double green_x, double green_y, double blue_x, double blue_y) +{ + png_set_cHRM_fixed(png_ptr, info_ptr, + png_fixed(png_ptr, white_x, "cHRM White X"), + png_fixed(png_ptr, white_y, "cHRM White Y"), + png_fixed(png_ptr, red_x, "cHRM Red X"), + png_fixed(png_ptr, red_y, "cHRM Red Y"), + png_fixed(png_ptr, green_x, "cHRM Green X"), + png_fixed(png_ptr, green_y, "cHRM Green Y"), + png_fixed(png_ptr, blue_x, "cHRM Blue X"), + png_fixed(png_ptr, blue_y, "cHRM Blue Y")); +} + +void PNGAPI +png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X, + double red_Y, double red_Z, double green_X, double green_Y, double green_Z, + double blue_X, double blue_Y, double blue_Z) +{ + png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, + png_fixed(png_ptr, red_X, "cHRM Red X"), + png_fixed(png_ptr, red_Y, "cHRM Red Y"), + png_fixed(png_ptr, red_Z, "cHRM Red Z"), + png_fixed(png_ptr, green_X, "cHRM Green X"), + png_fixed(png_ptr, green_Y, "cHRM Green Y"), + png_fixed(png_ptr, green_Z, "cHRM Green Z"), + png_fixed(png_ptr, blue_X, "cHRM Blue X"), + png_fixed(png_ptr, blue_Y, "cHRM Blue Y"), + png_fixed(png_ptr, blue_Z, "cHRM Blue Z")); +} +# endif /* FLOATING_POINT */ + +#endif /* cHRM */ + +#ifdef PNG_gAMA_SUPPORTED +void PNGFAPI +png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr, + png_fixed_point file_gamma) +{ + png_debug1(1, "in %s storage function", "gAMA"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma); + png_colorspace_sync_info(png_ptr, info_ptr); +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma) +{ + png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma, + "png_set_gAMA")); +} +# endif +#endif + +#ifdef PNG_hIST_SUPPORTED +void PNGAPI +png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_uint_16p hist) +{ + int i; + + png_debug1(1, "in %s storage function", "hIST"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (info_ptr->num_palette == 0 || info_ptr->num_palette + > PNG_MAX_PALETTE_LENGTH) + { + png_warning(png_ptr, + "Invalid palette size, hIST allocation skipped"); + + return; + } + + png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0); + + /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in + * version 1.2.1 + */ + info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr, + PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16)))); + + if (info_ptr->hist == NULL) + { + png_warning(png_ptr, "Insufficient memory for hIST chunk data"); + + return; + } + + info_ptr->free_me |= PNG_FREE_HIST; + + for (i = 0; i < info_ptr->num_palette; i++) + info_ptr->hist[i] = hist[i]; + + info_ptr->valid |= PNG_INFO_hIST; +} +#endif + +void PNGAPI +png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) +{ + png_debug1(1, "in %s storage function", "IHDR"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->width = width; + info_ptr->height = height; + info_ptr->bit_depth = (png_byte)bit_depth; + info_ptr->color_type = (png_byte)color_type; + info_ptr->compression_type = (png_byte)compression_type; + info_ptr->filter_type = (png_byte)filter_type; + info_ptr->interlace_type = (png_byte)interlace_type; + + png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, + info_ptr->compression_type, info_ptr->filter_type); + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + + else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) + info_ptr->channels = 3; + + else + info_ptr->channels = 1; + + if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) + info_ptr->channels++; + + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth); + + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width); +} + +#ifdef PNG_oFFs_SUPPORTED +void PNGAPI +png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr, + png_int_32 offset_x, png_int_32 offset_y, int unit_type) +{ + png_debug1(1, "in %s storage function", "oFFs"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_offset = offset_x; + info_ptr->y_offset = offset_y; + info_ptr->offset_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_oFFs; +} +#endif + +#ifdef PNG_pCAL_SUPPORTED +void PNGAPI +png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, + int nparams, png_const_charp units, png_charpp params) +{ + png_size_t length; + int i; + + png_debug1(1, "in %s storage function", "pCAL"); + + if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL + || (nparams > 0 && params == NULL)) + return; + + length = strlen(purpose) + 1; + png_debug1(3, "allocating purpose for info (%lu bytes)", + (unsigned long)length); + + /* TODO: validate format of calibration name and unit name */ + + /* Check that the type matches the specification. */ + if (type < 0 || type > 3) + png_error(png_ptr, "Invalid pCAL equation type"); + + if (nparams < 0 || nparams > 255) + png_error(png_ptr, "Invalid pCAL parameter count"); + + /* Validate params[nparams] */ + for (i=0; i<nparams; ++i) + { + if (params[i] == NULL || + !png_check_fp_string(params[i], strlen(params[i]))) + png_error(png_ptr, "Invalid format for pCAL parameter"); + } + + info_ptr->pcal_purpose = png_voidcast(png_charp, + png_malloc_warn(png_ptr, length)); + + if (info_ptr->pcal_purpose == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL purpose"); + + return; + } + + memcpy(info_ptr->pcal_purpose, purpose, length); + + png_debug(3, "storing X0, X1, type, and nparams in info"); + info_ptr->pcal_X0 = X0; + info_ptr->pcal_X1 = X1; + info_ptr->pcal_type = (png_byte)type; + info_ptr->pcal_nparams = (png_byte)nparams; + + length = strlen(units) + 1; + png_debug1(3, "allocating units for info (%lu bytes)", + (unsigned long)length); + + info_ptr->pcal_units = png_voidcast(png_charp, + png_malloc_warn(png_ptr, length)); + + if (info_ptr->pcal_units == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL units"); + + return; + } + + memcpy(info_ptr->pcal_units, units, length); + + info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr, + (png_size_t)((nparams + 1) * (sizeof (png_charp))))); + + if (info_ptr->pcal_params == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL params"); + + return; + } + + memset(info_ptr->pcal_params, 0, (nparams + 1) * (sizeof (png_charp))); + + for (i = 0; i < nparams; i++) + { + length = strlen(params[i]) + 1; + png_debug2(3, "allocating parameter %d for info (%lu bytes)", i, + (unsigned long)length); + + info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length); + + if (info_ptr->pcal_params[i] == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL parameter"); + + return; + } + + memcpy(info_ptr->pcal_params[i], params[i], length); + } + + info_ptr->valid |= PNG_INFO_pCAL; + info_ptr->free_me |= PNG_FREE_PCAL; +} +#endif + +#ifdef PNG_sCAL_SUPPORTED +void PNGAPI +png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr, + int unit, png_const_charp swidth, png_const_charp sheight) +{ + png_size_t lengthw = 0, lengthh = 0; + + png_debug1(1, "in %s storage function", "sCAL"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Double check the unit (should never get here with an invalid + * unit unless this is an API call.) + */ + if (unit != 1 && unit != 2) + png_error(png_ptr, "Invalid sCAL unit"); + + if (swidth == NULL || (lengthw = strlen(swidth)) == 0 || + swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw)) + png_error(png_ptr, "Invalid sCAL width"); + + if (sheight == NULL || (lengthh = strlen(sheight)) == 0 || + sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh)) + png_error(png_ptr, "Invalid sCAL height"); + + info_ptr->scal_unit = (png_byte)unit; + + ++lengthw; + + png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw); + + info_ptr->scal_s_width = png_voidcast(png_charp, + png_malloc_warn(png_ptr, lengthw)); + + if (info_ptr->scal_s_width == NULL) + { + png_warning(png_ptr, "Memory allocation failed while processing sCAL"); + + return; + } + + memcpy(info_ptr->scal_s_width, swidth, lengthw); + + ++lengthh; + + png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh); + + info_ptr->scal_s_height = png_voidcast(png_charp, + png_malloc_warn(png_ptr, lengthh)); + + if (info_ptr->scal_s_height == NULL) + { + png_free (png_ptr, info_ptr->scal_s_width); + info_ptr->scal_s_width = NULL; + + png_warning(png_ptr, "Memory allocation failed while processing sCAL"); + + return; + } + + memcpy(info_ptr->scal_s_height, sheight, lengthh); + + info_ptr->valid |= PNG_INFO_sCAL; + info_ptr->free_me |= PNG_FREE_SCAL; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit, + double width, double height) +{ + png_debug1(1, "in %s storage function", "sCAL"); + + /* Check the arguments. */ + if (width <= 0) + png_warning(png_ptr, "Invalid sCAL width ignored"); + + else if (height <= 0) + png_warning(png_ptr, "Invalid sCAL height ignored"); + + else + { + /* Convert 'width' and 'height' to ASCII. */ + char swidth[PNG_sCAL_MAX_DIGITS+1]; + char sheight[PNG_sCAL_MAX_DIGITS+1]; + + png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width, + PNG_sCAL_PRECISION); + png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height, + PNG_sCAL_PRECISION); + + png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); + } +} +# endif + +# ifdef PNG_FIXED_POINT_SUPPORTED +void PNGAPI +png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit, + png_fixed_point width, png_fixed_point height) +{ + png_debug1(1, "in %s storage function", "sCAL"); + + /* Check the arguments. */ + if (width <= 0) + png_warning(png_ptr, "Invalid sCAL width ignored"); + + else if (height <= 0) + png_warning(png_ptr, "Invalid sCAL height ignored"); + + else + { + /* Convert 'width' and 'height' to ASCII. */ + char swidth[PNG_sCAL_MAX_DIGITS+1]; + char sheight[PNG_sCAL_MAX_DIGITS+1]; + + png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width); + png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height); + + png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); + } +} +# endif +#endif + +#ifdef PNG_pHYs_SUPPORTED +void PNGAPI +png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr, + png_uint_32 res_x, png_uint_32 res_y, int unit_type) +{ + png_debug1(1, "in %s storage function", "pHYs"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_pixels_per_unit = res_x; + info_ptr->y_pixels_per_unit = res_y; + info_ptr->phys_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_pHYs; +} +#endif + +void PNGAPI +png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr, + png_const_colorp palette, int num_palette) +{ + + png_uint_32 max_palette_length; + + png_debug1(1, "in %s storage function", "PLTE"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ? + (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH; + + if (num_palette < 0 || num_palette > (int) max_palette_length) + { + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_error(png_ptr, "Invalid palette length"); + + else + { + png_warning(png_ptr, "Invalid palette length"); + + return; + } + } + + if ((num_palette > 0 && palette == NULL) || + (num_palette == 0 +# ifdef PNG_MNG_FEATURES_SUPPORTED + && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 +# endif + )) + { + png_error(png_ptr, "Invalid palette"); + } + + /* It may not actually be necessary to set png_ptr->palette here; + * we do it for backward compatibility with the way the png_handle_tRNS + * function used to do the allocation. + * + * 1.6.0: the above statement appears to be incorrect; something has to set + * the palette inside png_struct on read. + */ + png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0); + + /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead + * of num_palette entries, in case of an invalid PNG file or incorrect + * call to png_set_PLTE() with too-large sample values. + */ + png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr, + PNG_MAX_PALETTE_LENGTH * (sizeof (png_color)))); + + if (num_palette > 0) + memcpy(png_ptr->palette, palette, num_palette * (sizeof (png_color))); + info_ptr->palette = png_ptr->palette; + info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette; + + info_ptr->free_me |= PNG_FREE_PLTE; + + info_ptr->valid |= PNG_INFO_PLTE; +} + +#ifdef PNG_sBIT_SUPPORTED +void PNGAPI +png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_color_8p sig_bit) +{ + png_debug1(1, "in %s storage function", "sBIT"); + + if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL) + return; + + info_ptr->sig_bit = *sig_bit; + info_ptr->valid |= PNG_INFO_sBIT; +} +#endif + +#ifdef PNG_sRGB_SUPPORTED +void PNGAPI +png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent) +{ + png_debug1(1, "in %s storage function", "sRGB"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent); + png_colorspace_sync_info(png_ptr, info_ptr); +} + +void PNGAPI +png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, + int srgb_intent) +{ + png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, + srgb_intent) != 0) + { + /* This causes the gAMA and cHRM to be written too */ + info_ptr->colorspace.flags |= + PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM; + } + + png_colorspace_sync_info(png_ptr, info_ptr); +} +#endif /* sRGB */ + + +#ifdef PNG_iCCP_SUPPORTED +void PNGAPI +png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_charp name, int compression_type, + png_const_bytep profile, png_uint_32 proflen) +{ + png_charp new_iccp_name; + png_bytep new_iccp_profile; + png_size_t length; + + png_debug1(1, "in %s storage function", "iCCP"); + + if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL) + return; + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + png_app_error(png_ptr, "Invalid iCCP compression method"); + + /* Set the colorspace first because this validates the profile; do not + * override previously set app cHRM or gAMA here (because likely as not the + * application knows better than libpng what the correct values are.) Pass + * the info_ptr color_type field to png_colorspace_set_ICC because in the + * write case it has not yet been stored in png_ptr. + */ + { + int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name, + proflen, profile, info_ptr->color_type); + + png_colorspace_sync_info(png_ptr, info_ptr); + + /* Don't do any of the copying if the profile was bad, or inconsistent. */ + if (result == 0) + return; + + /* But do write the gAMA and cHRM chunks from the profile. */ + info_ptr->colorspace.flags |= + PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM; + } + + length = strlen(name)+1; + new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length)); + + if (new_iccp_name == NULL) + { + png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk"); + + return; + } + + memcpy(new_iccp_name, name, length); + new_iccp_profile = png_voidcast(png_bytep, + png_malloc_warn(png_ptr, proflen)); + + if (new_iccp_profile == NULL) + { + png_free(png_ptr, new_iccp_name); + png_benign_error(png_ptr, + "Insufficient memory to process iCCP profile"); + + return; + } + + memcpy(new_iccp_profile, profile, proflen); + + png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0); + + info_ptr->iccp_proflen = proflen; + info_ptr->iccp_name = new_iccp_name; + info_ptr->iccp_profile = new_iccp_profile; + info_ptr->free_me |= PNG_FREE_ICCP; + info_ptr->valid |= PNG_INFO_iCCP; +} +#endif + +#ifdef PNG_TEXT_SUPPORTED +void PNGAPI +png_set_text(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_textp text_ptr, int num_text) +{ + int ret; + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text); + + if (ret != 0) + png_error(png_ptr, "Insufficient memory to store text"); +} + +int /* PRIVATE */ +png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_textp text_ptr, int num_text) +{ + int i; + + png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U : + (unsigned long)png_ptr->chunk_name); + + if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL) + return(0); + + /* Make sure we have enough space in the "text" array in info_struct + * to hold all of the incoming text_ptr objects. This compare can't overflow + * because max_text >= num_text (anyway, subtract of two positive integers + * can't overflow in any case.) + */ + if (num_text > info_ptr->max_text - info_ptr->num_text) + { + int old_num_text = info_ptr->num_text; + int max_text; + png_textp new_text = NULL; + + /* Calculate an appropriate max_text, checking for overflow. */ + max_text = old_num_text; + if (num_text <= INT_MAX - max_text) + { + max_text += num_text; + + /* Round up to a multiple of 8 */ + if (max_text < INT_MAX-8) + max_text = (max_text + 8) & ~0x7; + + else + max_text = INT_MAX; + + /* Now allocate a new array and copy the old members in; this does all + * the overflow checks. + */ + new_text = png_voidcast(png_textp,png_realloc_array(png_ptr, + info_ptr->text, old_num_text, max_text-old_num_text, + sizeof *new_text)); + } + + if (new_text == NULL) + { + png_chunk_report(png_ptr, "too many text chunks", + PNG_CHUNK_WRITE_ERROR); + + return 1; + } + + png_free(png_ptr, info_ptr->text); + + info_ptr->text = new_text; + info_ptr->free_me |= PNG_FREE_TEXT; + info_ptr->max_text = max_text; + /* num_text is adjusted below as the entries are copied in */ + + png_debug1(3, "allocated %d entries for info_ptr->text", max_text); + } + + for (i = 0; i < num_text; i++) + { + size_t text_length, key_len; + size_t lang_len, lang_key_len; + png_textp textp = &(info_ptr->text[info_ptr->num_text]); + + if (text_ptr[i].key == NULL) + continue; + + if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE || + text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST) + { + png_chunk_report(png_ptr, "text compression mode is out of range", + PNG_CHUNK_WRITE_ERROR); + continue; + } + + key_len = strlen(text_ptr[i].key); + + if (text_ptr[i].compression <= 0) + { + lang_len = 0; + lang_key_len = 0; + } + + else +# ifdef PNG_iTXt_SUPPORTED + { + /* Set iTXt data */ + + if (text_ptr[i].lang != NULL) + lang_len = strlen(text_ptr[i].lang); + + else + lang_len = 0; + + if (text_ptr[i].lang_key != NULL) + lang_key_len = strlen(text_ptr[i].lang_key); + + else + lang_key_len = 0; + } +# else /* iTXt */ + { + png_chunk_report(png_ptr, "iTXt chunk not supported", + PNG_CHUNK_WRITE_ERROR); + continue; + } +# endif + + if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0') + { + text_length = 0; +# ifdef PNG_iTXt_SUPPORTED + if (text_ptr[i].compression > 0) + textp->compression = PNG_ITXT_COMPRESSION_NONE; + + else +# endif + textp->compression = PNG_TEXT_COMPRESSION_NONE; + } + + else + { + text_length = strlen(text_ptr[i].text); + textp->compression = text_ptr[i].compression; + } + + textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr, + key_len + text_length + lang_len + lang_key_len + 4)); + + if (textp->key == NULL) + { + png_chunk_report(png_ptr, "text chunk: out of memory", + PNG_CHUNK_WRITE_ERROR); + + return 1; + } + + png_debug2(2, "Allocated %lu bytes at %p in png_set_text", + (unsigned long)(png_uint_32) + (key_len + lang_len + lang_key_len + text_length + 4), + textp->key); + + memcpy(textp->key, text_ptr[i].key, key_len); + *(textp->key + key_len) = '\0'; + + if (text_ptr[i].compression > 0) + { + textp->lang = textp->key + key_len + 1; + memcpy(textp->lang, text_ptr[i].lang, lang_len); + *(textp->lang + lang_len) = '\0'; + textp->lang_key = textp->lang + lang_len + 1; + memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len); + *(textp->lang_key + lang_key_len) = '\0'; + textp->text = textp->lang_key + lang_key_len + 1; + } + + else + { + textp->lang=NULL; + textp->lang_key=NULL; + textp->text = textp->key + key_len + 1; + } + + if (text_length != 0) + memcpy(textp->text, text_ptr[i].text, text_length); + + *(textp->text + text_length) = '\0'; + +# ifdef PNG_iTXt_SUPPORTED + if (textp->compression > 0) + { + textp->text_length = 0; + textp->itxt_length = text_length; + } + + else +# endif + { + textp->text_length = text_length; + textp->itxt_length = 0; + } + + info_ptr->num_text++; + png_debug1(3, "transferred text chunk %d", info_ptr->num_text); + } + + return(0); +} +#endif + +#ifdef PNG_tIME_SUPPORTED +void PNGAPI +png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr, + png_const_timep mod_time) +{ + png_debug1(1, "in %s storage function", "tIME"); + + if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL || + (png_ptr->mode & PNG_WROTE_tIME) != 0) + return; + + if (mod_time->month == 0 || mod_time->month > 12 || + mod_time->day == 0 || mod_time->day > 31 || + mod_time->hour > 23 || mod_time->minute > 59 || + mod_time->second > 60) + { + png_warning(png_ptr, "Ignoring invalid time value"); + + return; + } + + info_ptr->mod_time = *mod_time; + info_ptr->valid |= PNG_INFO_tIME; +} +#endif + +#ifdef PNG_tRNS_SUPPORTED +void PNGAPI +png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr, + png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color) +{ + png_debug1(1, "in %s storage function", "tRNS"); + + if (png_ptr == NULL || info_ptr == NULL) + + return; + + if (trans_alpha != NULL) + { + /* It may not actually be necessary to set png_ptr->trans_alpha here; + * we do it for backward compatibility with the way the png_handle_tRNS + * function used to do the allocation. + * + * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively + * relies on png_set_tRNS storing the information in png_struct + * (otherwise it won't be there for the code in pngrtran.c). + */ + + png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0); + + if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH) + { + /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */ + info_ptr->trans_alpha = png_voidcast(png_bytep, + png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH)); + memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans); + } + png_ptr->trans_alpha = info_ptr->trans_alpha; + } + + if (trans_color != NULL) + { +#ifdef PNG_WARNINGS_SUPPORTED + if (info_ptr->bit_depth < 16) + { + int sample_max = (1 << info_ptr->bit_depth) - 1; + + if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY && + trans_color->gray > sample_max) || + (info_ptr->color_type == PNG_COLOR_TYPE_RGB && + (trans_color->red > sample_max || + trans_color->green > sample_max || + trans_color->blue > sample_max))) + png_warning(png_ptr, + "tRNS chunk has out-of-range samples for bit_depth"); + } +#endif + + info_ptr->trans_color = *trans_color; + + if (num_trans == 0) + num_trans = 1; + } + + info_ptr->num_trans = (png_uint_16)num_trans; + + if (num_trans != 0) + { + info_ptr->valid |= PNG_INFO_tRNS; + info_ptr->free_me |= PNG_FREE_TRNS; + } +} +#endif + +#ifdef PNG_sPLT_SUPPORTED +void PNGAPI +png_set_sPLT(png_const_structrp png_ptr, + png_inforp info_ptr, png_const_sPLT_tp entries, int nentries) +/* + * entries - array of png_sPLT_t structures + * to be added to the list of palettes + * in the info structure. + * + * nentries - number of palette structures to be + * added. + */ +{ + png_sPLT_tp np; + + if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL) + return; + + /* Use the internal realloc function, which checks for all the possible + * overflows. Notice that the parameters are (int) and (size_t) + */ + np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr, + info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries, + sizeof *np)); + + if (np == NULL) + { + /* Out of memory or too many chunks */ + png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR); + + return; + } + + png_free(png_ptr, info_ptr->splt_palettes); + info_ptr->splt_palettes = np; + info_ptr->free_me |= PNG_FREE_SPLT; + + np += info_ptr->splt_palettes_num; + + do + { + png_size_t length; + + /* Skip invalid input entries */ + if (entries->name == NULL || entries->entries == NULL) + { + /* png_handle_sPLT doesn't do this, so this is an app error */ + png_app_error(png_ptr, "png_set_sPLT: invalid sPLT"); + /* Just skip the invalid entry */ + continue; + } + + np->depth = entries->depth; + + /* In the event of out-of-memory just return - there's no point keeping + * on trying to add sPLT chunks. + */ + length = strlen(entries->name) + 1; + np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length)); + + if (np->name == NULL) + break; + + memcpy(np->name, entries->name, length); + + /* IMPORTANT: we have memory now that won't get freed if something else + * goes wrong; this code must free it. png_malloc_array produces no + * warnings; use a png_chunk_report (below) if there is an error. + */ + np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr, + entries->nentries, sizeof (png_sPLT_entry))); + + if (np->entries == NULL) + { + png_free(png_ptr, np->name); + np->name = NULL; + break; + } + + np->nentries = entries->nentries; + /* This multiply can't overflow because png_malloc_array has already + * checked it when doing the allocation. + */ + memcpy(np->entries, entries->entries, + entries->nentries * sizeof (png_sPLT_entry)); + + /* Note that 'continue' skips the advance of the out pointer and out + * count, so an invalid entry is not added. + */ + info_ptr->valid |= PNG_INFO_sPLT; + ++(info_ptr->splt_palettes_num); + ++np; + } + while (++entries, --nentries); + + if (nentries > 0) + png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR); +} +#endif /* sPLT */ + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +static png_byte +check_location(png_const_structrp png_ptr, int location) +{ + location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT); + + /* New in 1.6.0; copy the location and check it. This is an API + * change; previously the app had to use the + * png_set_unknown_chunk_location API below for each chunk. + */ + if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0) + { + /* Write struct, so unknown chunks come from the app */ + png_app_warning(png_ptr, + "png_set_unknown_chunks now expects a valid location"); + /* Use the old behavior */ + location = (png_byte)(png_ptr->mode & + (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)); + } + + /* This need not be an internal error - if the app calls + * png_set_unknown_chunks on a read pointer it must get the location right. + */ + if (location == 0) + png_error(png_ptr, "invalid location in png_set_unknown_chunks"); + + /* Now reduce the location to the top-most set bit by removing each least + * significant bit in turn. + */ + while (location != (location & -location)) + location &= ~(location & -location); + + /* The cast is safe because 'location' is a bit mask and only the low four + * bits are significant. + */ + return (png_byte)location; +} + +void PNGAPI +png_set_unknown_chunks(png_const_structrp png_ptr, + png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns) +{ + png_unknown_chunkp np; + + if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 || + unknowns == NULL) + return; + + /* Check for the failure cases where support has been disabled at compile + * time. This code is hardly ever compiled - it's here because + * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this + * code) but may be meaningless if the read or write handling of unknown + * chunks is not compiled in. + */ +# if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \ + defined(PNG_READ_SUPPORTED) + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) + { + png_app_error(png_ptr, "no unknown chunk support on read"); + + return; + } +# endif +# if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \ + defined(PNG_WRITE_SUPPORTED) + if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) + { + png_app_error(png_ptr, "no unknown chunk support on write"); + + return; + } +# endif + + /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that + * unknown critical chunks could be lost with just a warning resulting in + * undefined behavior. Now png_chunk_report is used to provide behavior + * appropriate to read or write. + */ + np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr, + info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns, + sizeof *np)); + + if (np == NULL) + { + png_chunk_report(png_ptr, "too many unknown chunks", + PNG_CHUNK_WRITE_ERROR); + + return; + } + + png_free(png_ptr, info_ptr->unknown_chunks); + info_ptr->unknown_chunks = np; /* safe because it is initialized */ + info_ptr->free_me |= PNG_FREE_UNKN; + + np += info_ptr->unknown_chunks_num; + + /* Increment unknown_chunks_num each time round the loop to protect the + * just-allocated chunk data. + */ + for (; num_unknowns > 0; --num_unknowns, ++unknowns) + { + memcpy(np->name, unknowns->name, (sizeof np->name)); + np->name[(sizeof np->name)-1] = '\0'; + np->location = check_location(png_ptr, unknowns->location); + + if (unknowns->size == 0) + { + np->data = NULL; + np->size = 0; + } + + else + { + np->data = png_voidcast(png_bytep, + png_malloc_base(png_ptr, unknowns->size)); + + if (np->data == NULL) + { + png_chunk_report(png_ptr, "unknown chunk: out of memory", + PNG_CHUNK_WRITE_ERROR); + /* But just skip storing the unknown chunk */ + continue; + } + + memcpy(np->data, unknowns->data, unknowns->size); + np->size = unknowns->size; + } + + /* These increments are skipped on out-of-memory for the data - the + * unknown chunk entry gets overwritten if the png_chunk_report returns. + * This is correct in the read case (the chunk is just dropped.) + */ + ++np; + ++(info_ptr->unknown_chunks_num); + } +} + +void PNGAPI +png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr, + int chunk, int location) +{ + /* This API is pretty pointless in 1.6.0 because the location can be set + * before the call to png_set_unknown_chunks. + * + * TODO: add a png_app_warning in 1.7 + */ + if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && + chunk < info_ptr->unknown_chunks_num) + { + if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0) + { + png_app_error(png_ptr, "invalid unknown chunk location"); + /* Fake out the pre 1.6.0 behavior: */ + if ((location & PNG_HAVE_IDAT) != 0) /* undocumented! */ + location = PNG_AFTER_IDAT; + + else + location = PNG_HAVE_IHDR; /* also undocumented */ + } + + info_ptr->unknown_chunks[chunk].location = + check_location(png_ptr, location); + } +} +#endif /* STORE_UNKNOWN_CHUNKS */ + +#ifdef PNG_MNG_FEATURES_SUPPORTED +png_uint_32 PNGAPI +png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features) +{ + png_debug(1, "in png_permit_mng_features"); + + if (png_ptr == NULL) + return 0; + + png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES; + + return png_ptr->mng_features_permitted; +} +#endif + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +static unsigned int +add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep) +{ + unsigned int i; + + /* Utility function: update the 'keep' state of a chunk if it is already in + * the list, otherwise add it to the list. + */ + for (i=0; i<count; ++i, list += 5) + { + if (memcmp(list, add, 4) == 0) + { + list[4] = (png_byte)keep; + + return count; + } + } + + if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT) + { + ++count; + memcpy(list, add, 4); + list[4] = (png_byte)keep; + } + + return count; +} + +void PNGAPI +png_set_keep_unknown_chunks(png_structrp png_ptr, int keep, + png_const_bytep chunk_list, int num_chunks_in) +{ + png_bytep new_list; + unsigned int num_chunks, old_num_chunks; + + if (png_ptr == NULL) + return; + + if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST) + { + png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep"); + + return; + } + + if (num_chunks_in <= 0) + { + png_ptr->unknown_default = keep; + + /* '0' means just set the flags, so stop here */ + if (num_chunks_in == 0) + return; + } + + if (num_chunks_in < 0) + { + /* Ignore all unknown chunks and all chunks recognized by + * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND + */ + static PNG_CONST png_byte chunks_to_ignore[] = { + 98, 75, 71, 68, '\0', /* bKGD */ + 99, 72, 82, 77, '\0', /* cHRM */ + 103, 65, 77, 65, '\0', /* gAMA */ + 104, 73, 83, 84, '\0', /* hIST */ + 105, 67, 67, 80, '\0', /* iCCP */ + 105, 84, 88, 116, '\0', /* iTXt */ + 111, 70, 70, 115, '\0', /* oFFs */ + 112, 67, 65, 76, '\0', /* pCAL */ + 112, 72, 89, 115, '\0', /* pHYs */ + 115, 66, 73, 84, '\0', /* sBIT */ + 115, 67, 65, 76, '\0', /* sCAL */ + 115, 80, 76, 84, '\0', /* sPLT */ + 115, 84, 69, 82, '\0', /* sTER */ + 115, 82, 71, 66, '\0', /* sRGB */ + 116, 69, 88, 116, '\0', /* tEXt */ + 116, 73, 77, 69, '\0', /* tIME */ + 122, 84, 88, 116, '\0' /* zTXt */ + }; + + chunk_list = chunks_to_ignore; + num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U; + } + + else /* num_chunks_in > 0 */ + { + if (chunk_list == NULL) + { + /* Prior to 1.6.0 this was silently ignored, now it is an app_error + * which can be switched off. + */ + png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list"); + + return; + } + + num_chunks = num_chunks_in; + } + + old_num_chunks = png_ptr->num_chunk_list; + if (png_ptr->chunk_list == NULL) + old_num_chunks = 0; + + /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow. + */ + if (num_chunks + old_num_chunks > UINT_MAX/5) + { + png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks"); + + return; + } + + /* If these chunks are being reset to the default then no more memory is + * required because add_one_chunk above doesn't extend the list if the 'keep' + * parameter is the default. + */ + if (keep != 0) + { + new_list = png_voidcast(png_bytep, png_malloc(png_ptr, + 5 * (num_chunks + old_num_chunks))); + + if (old_num_chunks > 0) + memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks); + } + + else if (old_num_chunks > 0) + new_list = png_ptr->chunk_list; + + else + new_list = NULL; + + /* Add the new chunks together with each one's handling code. If the chunk + * already exists the code is updated, otherwise the chunk is added to the + * end. (In libpng 1.6.0 order no longer matters because this code enforces + * the earlier convention that the last setting is the one that is used.) + */ + if (new_list != NULL) + { + png_const_bytep inlist; + png_bytep outlist; + unsigned int i; + + for (i=0; i<num_chunks; ++i) + { + old_num_chunks = add_one_chunk(new_list, old_num_chunks, + chunk_list+5*i, keep); + } + + /* Now remove any spurious 'default' entries. */ + num_chunks = 0; + for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5) + { + if (inlist[4]) + { + if (outlist != inlist) + memcpy(outlist, inlist, 5); + outlist += 5; + ++num_chunks; + } + } + + /* This means the application has removed all the specialized handling. */ + if (num_chunks == 0) + { + if (png_ptr->chunk_list != new_list) + png_free(png_ptr, new_list); + + new_list = NULL; + } + } + + else + num_chunks = 0; + + png_ptr->num_chunk_list = num_chunks; + + if (png_ptr->chunk_list != new_list) + { + if (png_ptr->chunk_list != NULL) + png_free(png_ptr, png_ptr->chunk_list); + + png_ptr->chunk_list = new_list; + } +} +#endif + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED +void PNGAPI +png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr, + png_user_chunk_ptr read_user_chunk_fn) +{ + png_debug(1, "in png_set_read_user_chunk_fn"); + + if (png_ptr == NULL) + return; + + png_ptr->read_user_chunk_fn = read_user_chunk_fn; + png_ptr->user_chunk_ptr = user_chunk_ptr; +} +#endif + +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr, + png_bytepp row_pointers) +{ + png_debug1(1, "in %s storage function", "rows"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (info_ptr->row_pointers != NULL && + (info_ptr->row_pointers != row_pointers)) + png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); + + info_ptr->row_pointers = row_pointers; + + if (row_pointers != NULL) + info_ptr->valid |= PNG_INFO_IDAT; +} +#endif + +void PNGAPI +png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size) +{ + if (png_ptr == NULL) + return; + + if (size == 0 || size > PNG_UINT_31_MAX) + png_error(png_ptr, "invalid compression buffer size"); + +# ifdef PNG_SEQUENTIAL_READ_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) + { + png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */ + return; + } +# endif + +# ifdef PNG_WRITE_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0) + { + if (png_ptr->zowner != 0) + { + png_warning(png_ptr, + "Compression buffer size cannot be changed because it is in use"); + + return; + } + +#ifndef __COVERITY__ + /* Some compilers complain that this is always false. However, it + * can be true when integer overflow happens. + */ + if (size > ZLIB_IO_MAX) + { + png_warning(png_ptr, + "Compression buffer size limited to system maximum"); + size = ZLIB_IO_MAX; /* must fit */ + } +#endif + + if (size < 6) + { + /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH + * if this is permitted. + */ + png_warning(png_ptr, + "Compression buffer size cannot be reduced below 6"); + + return; + } + + if (png_ptr->zbuffer_size != size) + { + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); + png_ptr->zbuffer_size = (uInt)size; + } + } +# endif +} + +void PNGAPI +png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask) +{ + if (png_ptr != NULL && info_ptr != NULL) + info_ptr->valid &= ~mask; +} + + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +/* This function was added to libpng 1.2.6 */ +void PNGAPI +png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max, + png_uint_32 user_height_max) +{ + /* Images with dimensions larger than these limits will be + * rejected by png_set_IHDR(). To accept any PNG datastream + * regardless of dimensions, set both limits to 0x7fffffff. + */ + if (png_ptr == NULL) + return; + + png_ptr->user_width_max = user_width_max; + png_ptr->user_height_max = user_height_max; +} + +/* This function was added to libpng 1.4.0 */ +void PNGAPI +png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max) +{ + if (png_ptr != NULL) + png_ptr->user_chunk_cache_max = user_chunk_cache_max; +} + +/* This function was added to libpng 1.4.1 */ +void PNGAPI +png_set_chunk_malloc_max (png_structrp png_ptr, + png_alloc_size_t user_chunk_malloc_max) +{ + if (png_ptr != NULL) + png_ptr->user_chunk_malloc_max = user_chunk_malloc_max; +} +#endif /* ?SET_USER_LIMITS */ + + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_set_benign_errors(png_structrp png_ptr, int allowed) +{ + png_debug(1, "in png_set_benign_errors"); + + /* If allowed is 1, png_benign_error() is treated as a warning. + * + * If allowed is 0, png_benign_error() is treated as an error (which + * is the default behavior if png_set_benign_errors() is not called). + */ + + if (allowed != 0) + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN | + PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN; + + else + png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN | + PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN); +} +#endif /* BENIGN_ERRORS */ + +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Whether to report invalid palette index; added at libng-1.5.10. + * It is possible for an indexed (color-type==3) PNG file to contain + * pixels with invalid (out-of-range) indexes if the PLTE chunk has + * fewer entries than the image's bit-depth would allow. We recover + * from this gracefully by filling any incomplete palette with zeros + * (opaque black). By default, when this occurs libpng will issue + * a benign error. This API can be used to override that behavior. + */ +void PNGAPI +png_set_check_for_invalid_index(png_structrp png_ptr, int allowed) +{ + png_debug(1, "in png_set_check_for_invalid_index"); + + if (allowed > 0) + png_ptr->num_palette_max = 0; + + else + png_ptr->num_palette_max = -1; +} +#endif + +#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \ + defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) +/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, + * and if invalid, correct the keyword rather than discarding the entire + * chunk. The PNG 1.0 specification requires keywords 1-79 characters in + * length, forbids leading or trailing whitespace, multiple internal spaces, + * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. + * + * The 'new_key' buffer must be 80 characters in size (for the keyword plus a + * trailing '\0'). If this routine returns 0 then there was no keyword, or a + * valid one could not be generated, and the caller must png_error. + */ +png_uint_32 /* PRIVATE */ +png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key) +{ + png_const_charp orig_key = key; + png_uint_32 key_len = 0; + int bad_character = 0; + int space = 1; + + png_debug(1, "in png_check_keyword"); + + if (key == NULL) + { + *new_key = 0; + return 0; + } + + while (*key && key_len < 79) + { + png_byte ch = (png_byte)*key++; + + if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/)) + *new_key++ = ch, ++key_len, space = 0; + + else if (space == 0) + { + /* A space or an invalid character when one wasn't seen immediately + * before; output just a space. + */ + *new_key++ = 32, ++key_len, space = 1; + + /* If the character was not a space then it is invalid. */ + if (ch != 32) + bad_character = ch; + } + + else if (bad_character == 0) + bad_character = ch; /* just skip it, record the first error */ + } + + if (key_len > 0 && space != 0) /* trailing space */ + { + --key_len, --new_key; + if (bad_character == 0) + bad_character = 32; + } + + /* Terminate the keyword */ + *new_key = 0; + + if (key_len == 0) + return 0; + +#ifdef PNG_WARNINGS_SUPPORTED + /* Try to only output one warning per keyword: */ + if (*key != 0) /* keyword too long */ + png_warning(png_ptr, "keyword truncated"); + + else if (bad_character != 0) + { + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter(p, 1, orig_key); + png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character); + + png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'"); + } +#endif /* WARNINGS */ + + return key_len; +} +#endif /* TEXT || pCAL || iCCP || sPLT */ +#endif /* READ || WRITE */ diff --git a/thirdparty/libpng/pngstruct.h b/thirdparty/libpng/pngstruct.h new file mode 100644 index 0000000000..c1f35edef5 --- /dev/null +++ b/thirdparty/libpng/pngstruct.h @@ -0,0 +1,483 @@ + +/* pngstruct.h - header file for PNG reference library + * + * Last changed in libpng 1.6.18 [July 23, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* The structure that holds the information to read and write PNG files. + * The only people who need to care about what is inside of this are the + * people who will be modifying the library for their own special needs. + * It should NOT be accessed directly by an application. + */ + +#ifndef PNGSTRUCT_H +#define PNGSTRUCT_H +/* zlib.h defines the structure z_stream, an instance of which is included + * in this structure and is required for decompressing the LZ compressed + * data in PNG files. + */ +#ifndef ZLIB_CONST + /* We must ensure that zlib uses 'const' in declarations. */ +# define ZLIB_CONST +#endif +#include "zlib.h" +#ifdef const + /* zlib.h sometimes #defines const to nothing, undo this. */ +# undef const +#endif + +/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility + * with older builds. + */ +#if ZLIB_VERNUM < 0x1260 +# define PNGZ_MSG_CAST(s) png_constcast(char*,s) +# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b) +#else +# define PNGZ_MSG_CAST(s) (s) +# define PNGZ_INPUT_CAST(b) (b) +#endif + +/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib + * can handle at once. This type need be no larger than 16 bits (so maximum of + * 65535), this define allows us to discover how big it is, but limited by the + * maximuum for png_size_t. The value can be overriden in a library build + * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably + * lower value (e.g. 255 works). A lower value may help memory usage (slightly) + * and may even improve performance on some systems (and degrade it on others.) + */ +#ifndef ZLIB_IO_MAX +# define ZLIB_IO_MAX ((uInt)-1) +#endif + +#ifdef PNG_WRITE_SUPPORTED +/* The type of a compression buffer list used by the write code. */ +typedef struct png_compression_buffer +{ + struct png_compression_buffer *next; + png_byte output[1]; /* actually zbuf_size */ +} png_compression_buffer, *png_compression_bufferp; + +#define PNG_COMPRESSION_BUFFER_SIZE(pp)\ + (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size) +#endif + +/* Colorspace support; structures used in png_struct, png_info and in internal + * functions to hold and communicate information about the color space. + * + * PNG_COLORSPACE_SUPPORTED is only required if the application will perform + * colorspace corrections, otherwise all the colorspace information can be + * skipped and the size of libpng can be reduced (significantly) by compiling + * out the colorspace support. + */ +#ifdef PNG_COLORSPACE_SUPPORTED +/* The chromaticities of the red, green and blue colorants and the chromaticity + * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)). + */ +typedef struct png_xy +{ + png_fixed_point redx, redy; + png_fixed_point greenx, greeny; + png_fixed_point bluex, bluey; + png_fixed_point whitex, whitey; +} png_xy; + +/* The same data as above but encoded as CIE XYZ values. When this data comes + * from chromaticities the sum of the Y values is assumed to be 1.0 + */ +typedef struct png_XYZ +{ + png_fixed_point red_X, red_Y, red_Z; + png_fixed_point green_X, green_Y, green_Z; + png_fixed_point blue_X, blue_Y, blue_Z; +} png_XYZ; +#endif /* COLORSPACE */ + +#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) +/* A colorspace is all the above plus, potentially, profile information; + * however at present libpng does not use the profile internally so it is only + * stored in the png_info struct (if iCCP is supported.) The rendering intent + * is retained here and is checked. + * + * The file gamma encoding information is also stored here and gamma correction + * is done by libpng, whereas color correction must currently be done by the + * application. + */ +typedef struct png_colorspace +{ +#ifdef PNG_GAMMA_SUPPORTED + png_fixed_point gamma; /* File gamma */ +#endif + +#ifdef PNG_COLORSPACE_SUPPORTED + png_xy end_points_xy; /* End points as chromaticities */ + png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */ + png_uint_16 rendering_intent; /* Rendering intent of a profile */ +#endif + + /* Flags are always defined to simplify the code. */ + png_uint_16 flags; /* As defined below */ +} png_colorspace, * PNG_RESTRICT png_colorspacerp; + +typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp; + +/* General flags for the 'flags' field */ +#define PNG_COLORSPACE_HAVE_GAMMA 0x0001 +#define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002 +#define PNG_COLORSPACE_HAVE_INTENT 0x0004 +#define PNG_COLORSPACE_FROM_gAMA 0x0008 +#define PNG_COLORSPACE_FROM_cHRM 0x0010 +#define PNG_COLORSPACE_FROM_sRGB 0x0020 +#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040 +#define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */ +#define PNG_COLORSPACE_INVALID 0x8000 +#define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags)) +#endif /* COLORSPACE || GAMMA */ + +struct png_struct_def +{ +#ifdef PNG_SETJMP_SUPPORTED + jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */ + png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ + jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */ + size_t jmp_buf_size; /* size of the above, if allocated */ +#endif + png_error_ptr error_fn; /* function for printing errors and aborting */ +#ifdef PNG_WARNINGS_SUPPORTED + png_error_ptr warning_fn; /* function for printing warnings */ +#endif + png_voidp error_ptr; /* user supplied struct for error functions */ + png_rw_ptr write_data_fn; /* function for writing output data */ + png_rw_ptr read_data_fn; /* function for reading input data */ + png_voidp io_ptr; /* ptr to application struct for I/O functions */ + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr read_user_transform_fn; /* user read transform */ +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr write_user_transform_fn; /* user write transform */ +#endif + +/* These were added in libpng-1.0.2 */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) + png_voidp user_transform_ptr; /* user supplied struct for user transform */ + png_byte user_transform_depth; /* bit depth of user transformed pixels */ + png_byte user_transform_channels; /* channels in user transformed pixels */ +#endif +#endif + + png_uint_32 mode; /* tells us where we are in the PNG file */ + png_uint_32 flags; /* flags indicating various things to libpng */ + png_uint_32 transformations; /* which transformations to perform */ + + png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */ + z_stream zstream; /* decompression structure */ + +#ifdef PNG_WRITE_SUPPORTED + png_compression_bufferp zbuffer_list; /* Created on demand during write */ + uInt zbuffer_size; /* size of the actual buffer */ + + int zlib_level; /* holds zlib compression level */ + int zlib_method; /* holds zlib compression method */ + int zlib_window_bits; /* holds zlib compression window bits */ + int zlib_mem_level; /* holds zlib compression memory level */ + int zlib_strategy; /* holds zlib compression strategy */ +#endif +/* Added at libpng 1.5.4 */ +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + int zlib_text_level; /* holds zlib compression level */ + int zlib_text_method; /* holds zlib compression method */ + int zlib_text_window_bits; /* holds zlib compression window bits */ + int zlib_text_mem_level; /* holds zlib compression memory level */ + int zlib_text_strategy; /* holds zlib compression strategy */ +#endif +/* End of material added at libpng 1.5.4 */ +/* Added at libpng 1.6.0 */ +#ifdef PNG_WRITE_SUPPORTED + int zlib_set_level; /* Actual values set into the zstream on write */ + int zlib_set_method; + int zlib_set_window_bits; + int zlib_set_mem_level; + int zlib_set_strategy; +#endif + + png_uint_32 width; /* width of image in pixels */ + png_uint_32 height; /* height of image in pixels */ + png_uint_32 num_rows; /* number of rows in current pass */ + png_uint_32 usr_width; /* width of row at start of write */ + png_size_t rowbytes; /* size of row in bytes */ + png_uint_32 iwidth; /* width of current interlaced row in pixels */ + png_uint_32 row_number; /* current row in interlace pass */ + png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */ + png_bytep prev_row; /* buffer to save previous (unfiltered) row. + * While reading this is a pointer into + * big_prev_row; while writing it is separately + * allocated if needed. + */ + png_bytep row_buf; /* buffer to save current (unfiltered) row. + * While reading, this is a pointer into + * big_row_buf; while writing it is separately + * allocated. + */ +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_bytep try_row; /* buffer to save trial row when filtering */ + png_bytep tst_row; /* buffer to save best trial row when filtering */ +#endif + png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */ + + png_uint_32 idat_size; /* current IDAT size for read */ + png_uint_32 crc; /* current chunk CRC value */ + png_colorp palette; /* palette from the input file */ + png_uint_16 num_palette; /* number of color entries in palette */ + +/* Added at libpng-1.5.10 */ +#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED + int num_palette_max; /* maximum palette index found in IDAT */ +#endif + + png_uint_16 num_trans; /* number of transparency values */ + png_byte compression; /* file compression type (always 0) */ + png_byte filter; /* file filter type (always 0) */ + png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + png_byte pass; /* current interlace pass (0 - 6) */ + png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ + png_byte color_type; /* color type of file */ + png_byte bit_depth; /* bit depth of file */ + png_byte usr_bit_depth; /* bit depth of users row: write only */ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte channels; /* number of channels in file */ +#ifdef PNG_WRITE_SUPPORTED + png_byte usr_channels; /* channels at start of write: write only */ +#endif + png_byte sig_bytes; /* magic bytes read/written from start of file */ + png_byte maximum_pixel_depth; + /* pixel depth used for the row buffers */ + png_byte transformed_pixel_depth; + /* pixel depth after read/write transforms */ +#if PNG_ZLIB_VERNUM >= 0x1240 + png_byte zstream_start; /* at start of an input zlib stream */ +#endif /* Zlib >= 1.2.4 */ +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) + png_uint_16 filler; /* filler bytes for pixel expansion */ +#endif + +#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) + png_byte background_gamma_type; + png_fixed_point background_gamma; + png_color_16 background; /* background color in screen gamma space */ +#ifdef PNG_READ_GAMMA_SUPPORTED + png_color_16 background_1; /* background normalized to gamma 1.0 */ +#endif +#endif /* bKGD */ + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_flush_ptr output_flush_fn; /* Function for flushing output */ + png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ + png_uint_32 flush_rows; /* number of rows written since last flush */ +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ + png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ + + png_bytep gamma_table; /* gamma table for 8-bit depth files */ + png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + png_bytep gamma_from_1; /* converts from 1.0 to screen */ + png_bytep gamma_to_1; /* converts from file to 1.0 */ + png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ + png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ +#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */ +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) + png_color_8 sig_bit; /* significant bits in each available channel */ +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) + png_color_8 shift; /* shift for significant bit tranformation */ +#endif + +#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ + || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + png_bytep trans_alpha; /* alpha values for paletted files */ + png_color_16 trans_color; /* transparent color for non-paletted files */ +#endif + + png_read_status_ptr read_row_fn; /* called after each row is decoded */ + png_write_status_ptr write_row_fn; /* called after each row is encoded */ +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_progressive_info_ptr info_fn; /* called after header data fully read */ + png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ + png_progressive_end_ptr end_fn; /* called after image is complete */ + png_bytep save_buffer_ptr; /* current location in save_buffer */ + png_bytep save_buffer; /* buffer for previously read data */ + png_bytep current_buffer_ptr; /* current location in current_buffer */ + png_bytep current_buffer; /* buffer for recently used data */ + png_uint_32 push_length; /* size of current input chunk */ + png_uint_32 skip_length; /* bytes to skip in input data */ + png_size_t save_buffer_size; /* amount of data now in save_buffer */ + png_size_t save_buffer_max; /* total size of save_buffer */ + png_size_t buffer_size; /* total amount of available input data */ + png_size_t current_buffer_size; /* amount of data now in current_buffer */ + int process_mode; /* what push library is currently doing */ + int cur_palette; /* current push library palette index */ + +#endif /* PROGRESSIVE_READ */ + +#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) +/* For the Borland special 64K segment handler */ + png_bytepp offset_table_ptr; + png_bytep offset_table; + png_uint_16 offset_table_number; + png_uint_16 offset_table_count; + png_uint_16 offset_table_count_free; +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + png_bytep palette_lookup; /* lookup table for quantizing */ + png_bytep quantize_index; /* index translation for palette files */ +#endif + +/* Options */ +#ifdef PNG_SET_OPTION_SUPPORTED + png_byte options; /* On/off state (up to 4 options) */ +#endif + +#if PNG_LIBPNG_VER < 10700 +/* To do: remove this from libpng-1.7 */ +#ifdef PNG_TIME_RFC1123_SUPPORTED + char time_buffer[29]; /* String to hold RFC 1123 time text */ +#endif +#endif + +/* New members added in libpng-1.0.6 */ + + png_uint_32 free_me; /* flags items libpng is responsible for freeing */ + +#ifdef PNG_USER_CHUNKS_SUPPORTED + png_voidp user_chunk_ptr; +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ +#endif +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + int unknown_default; /* As PNG_HANDLE_* */ + unsigned int num_chunk_list; /* Number of entries in the list */ + png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name + * followed by a PNG_HANDLE_* byte */ +#endif + +/* New members added in libpng-1.0.3 */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + png_byte rgb_to_gray_status; + /* Added in libpng 1.5.5 to record setting of coefficients: */ + png_byte rgb_to_gray_coefficients_set; + /* These were changed from png_byte in libpng-1.0.6 */ + png_uint_16 rgb_to_gray_red_coeff; + png_uint_16 rgb_to_gray_green_coeff; + /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */ +#endif + +/* New member added in libpng-1.0.4 (renamed in 1.0.9) */ +#if defined(PNG_MNG_FEATURES_SUPPORTED) +/* Changed from png_byte to png_uint_32 at version 1.2.0 */ + png_uint_32 mng_features_permitted; +#endif + +/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_byte filter_type; +#endif + +/* New members added in libpng-1.2.0 */ + +/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ +#ifdef PNG_USER_MEM_SUPPORTED + png_voidp mem_ptr; /* user supplied struct for mem functions */ + png_malloc_ptr malloc_fn; /* function for allocating memory */ + png_free_ptr free_fn; /* function for freeing memory */ +#endif + +/* New member added in libpng-1.0.13 and 1.2.0 */ + png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* The following three members were added at version 1.0.14 and 1.2.4 */ + png_bytep quantize_sort; /* working sort array */ + png_bytep index_to_palette; /* where the original index currently is + in the palette */ + png_bytep palette_to_index; /* which original index points to this + palette color */ +#endif + +/* New members added in libpng-1.0.16 and 1.2.6 */ + png_byte compression_type; + +#ifdef PNG_USER_LIMITS_SUPPORTED + png_uint_32 user_width_max; + png_uint_32 user_height_max; + + /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown + * chunks that can be stored (0 means unlimited). + */ + png_uint_32 user_chunk_cache_max; + + /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk + * can occupy when decompressed. 0 means unlimited. + */ + png_alloc_size_t user_chunk_malloc_max; +#endif + +/* New member added in libpng-1.0.25 and 1.2.17 */ +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + /* Temporary storage for unknown chunk that the library doesn't recognize, + * used while reading the chunk. + */ + png_unknown_chunk unknown_chunk; +#endif + +/* New member added in libpng-1.2.26 */ + png_size_t old_big_row_buf_size; + +#ifdef PNG_READ_SUPPORTED +/* New member added in libpng-1.2.30 */ + png_bytep read_buffer; /* buffer for reading chunk data */ + png_alloc_size_t read_buffer_size; /* current size of the buffer */ +#endif +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED + uInt IDAT_read_size; /* limit on read buffer size for IDAT */ +#endif + +#ifdef PNG_IO_STATE_SUPPORTED +/* New member added in libpng-1.4.0 */ + png_uint_32 io_state; +#endif + +/* New member added in libpng-1.5.6 */ + png_bytep big_prev_row; + +/* New member added in libpng-1.5.7 */ + void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info, + png_bytep row, png_const_bytep prev_row); + +#ifdef PNG_READ_SUPPORTED +#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) + png_colorspace colorspace; +#endif +#endif +}; +#endif /* PNGSTRUCT_H */ diff --git a/thirdparty/libpng/pngtrans.c b/thirdparty/libpng/pngtrans.c new file mode 100644 index 0000000000..7f8cc455d3 --- /dev/null +++ b/thirdparty/libpng/pngtrans.c @@ -0,0 +1,849 @@ + +/* pngtrans.c - transforms the data in a row (used by both readers and writers) + * + * Last changed in libpng 1.6.18 [July 23, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Turn on BGR-to-RGB mapping */ +void PNGAPI +png_set_bgr(png_structrp png_ptr) +{ + png_debug(1, "in png_set_bgr"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_BGR; +} +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Turn on 16-bit byte swapping */ +void PNGAPI +png_set_swap(png_structrp png_ptr) +{ + png_debug(1, "in png_set_swap"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth == 16) + png_ptr->transformations |= PNG_SWAP_BYTES; +} +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Turn on pixel packing */ +void PNGAPI +png_set_packing(png_structrp png_ptr) +{ + png_debug(1, "in png_set_packing"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth < 8) + { + png_ptr->transformations |= PNG_PACK; +# ifdef PNG_WRITE_SUPPORTED + png_ptr->usr_bit_depth = 8; +# endif + } +} +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Turn on packed pixel swapping */ +void PNGAPI +png_set_packswap(png_structrp png_ptr) +{ + png_debug(1, "in png_set_packswap"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth < 8) + png_ptr->transformations |= PNG_PACKSWAP; +} +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +void PNGAPI +png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits) +{ + png_debug(1, "in png_set_shift"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_SHIFT; + png_ptr->shift = *true_bits; +} +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +int PNGAPI +png_set_interlace_handling(png_structrp png_ptr) +{ + png_debug(1, "in png_set_interlace handling"); + + if (png_ptr != 0 && png_ptr->interlaced != 0) + { + png_ptr->transformations |= PNG_INTERLACE; + return (7); + } + + return (1); +} +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte on read, or remove a filler or alpha byte on write. + * The filler type has changed in v0.95 to allow future 2-byte fillers + * for 48-bit input data, as well as to avoid problems with some compilers + * that don't like bytes as parameters. + */ +void PNGAPI +png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc) +{ + png_debug(1, "in png_set_filler"); + + if (png_ptr == NULL) + return; + + /* In libpng 1.6 it is possible to determine whether this is a read or write + * operation and therefore to do more checking here for a valid call. + */ + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0) + { +# ifdef PNG_READ_FILLER_SUPPORTED + /* On read png_set_filler is always valid, regardless of the base PNG + * format, because other transformations can give a format where the + * filler code can execute (basically an 8 or 16-bit component RGB or G + * format.) + * + * NOTE: usr_channels is not used by the read code! (This has led to + * confusion in the past.) The filler is only used in the read code. + */ + png_ptr->filler = (png_uint_16)filler; +# else + png_app_error(png_ptr, "png_set_filler not supported on read"); + PNG_UNUSED(filler) /* not used in the write case */ + return; +# endif + } + + else /* write */ + { +# ifdef PNG_WRITE_FILLER_SUPPORTED + /* On write the usr_channels parameter must be set correctly at the + * start to record the number of channels in the app-supplied data. + */ + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_RGB: + png_ptr->usr_channels = 4; + break; + + case PNG_COLOR_TYPE_GRAY: + if (png_ptr->bit_depth >= 8) + { + png_ptr->usr_channels = 2; + break; + } + + else + { + /* There simply isn't any code in libpng to strip out bits + * from bytes when the components are less than a byte in + * size! + */ + png_app_error(png_ptr, + "png_set_filler is invalid for low bit depth gray output"); + return; + } + + default: + png_app_error(png_ptr, + "png_set_filler: inappropriate color type"); + return; + } +# else + png_app_error(png_ptr, "png_set_filler not supported on write"); + return; +# endif + } + + /* Here on success - libpng supports the operation, set the transformation + * and the flag to say where the filler channel is. + */ + png_ptr->transformations |= PNG_FILLER; + + if (filler_loc == PNG_FILLER_AFTER) + png_ptr->flags |= PNG_FLAG_FILLER_AFTER; + + else + png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; +} + +/* Added to libpng-1.2.7 */ +void PNGAPI +png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc) +{ + png_debug(1, "in png_set_add_alpha"); + + if (png_ptr == NULL) + return; + + png_set_filler(png_ptr, filler, filler_loc); + /* The above may fail to do anything. */ + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_ptr->transformations |= PNG_ADD_ALPHA; +} + +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +void PNGAPI +png_set_swap_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_swap_alpha"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_SWAP_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +void PNGAPI +png_set_invert_alpha(png_structrp png_ptr) +{ + png_debug(1, "in png_set_invert_alpha"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_INVERT_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +void PNGAPI +png_set_invert_mono(png_structrp png_ptr) +{ + png_debug(1, "in png_set_invert_mono"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_INVERT_MONO; +} + +/* Invert monochrome grayscale data */ +void /* PRIVATE */ +png_do_invert(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_invert"); + + /* This test removed from libpng version 1.0.13 and 1.2.0: + * if (row_info->bit_depth == 1 && + */ + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + png_bytep rp = row; + png_size_t i; + png_size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(~(*rp)); + rp++; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + row_info->bit_depth == 8) + { + png_bytep rp = row; + png_size_t i; + png_size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i += 2) + { + *rp = (png_byte)(~(*rp)); + rp += 2; + } + } + +#ifdef PNG_16BIT_SUPPORTED + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + row_info->bit_depth == 16) + { + png_bytep rp = row; + png_size_t i; + png_size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i += 4) + { + *rp = (png_byte)(~(*rp)); + *(rp + 1) = (png_byte)(~(*(rp + 1))); + rp += 4; + } + } +#endif +} +#endif + +#ifdef PNG_16BIT_SUPPORTED +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swaps byte order on 16-bit depth images */ +void /* PRIVATE */ +png_do_swap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_swap"); + + if (row_info->bit_depth == 16) + { + png_bytep rp = row; + png_uint_32 i; + png_uint_32 istop= row_info->width * row_info->channels; + + for (i = 0; i < istop; i++, rp += 2) + { +#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED + /* Feature added to libpng-1.6.11 for testing purposes, not + * enabled by default. + */ + *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp); +#else + png_byte t = *rp; + *rp = *(rp + 1); + *(rp + 1) = t; +#endif + } + } +} +#endif +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +static PNG_CONST png_byte onebppswaptable[256] = { + 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, + 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, + 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, + 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, + 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, + 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, + 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, + 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, + 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, + 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, + 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, + 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, + 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, + 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, + 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, + 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, + 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, + 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, + 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, + 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, + 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, + 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, + 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, + 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, + 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, + 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, + 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, + 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, + 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, + 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, + 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, + 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF +}; + +static PNG_CONST png_byte twobppswaptable[256] = { + 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, + 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, + 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, + 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, + 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, + 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, + 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, + 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, + 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, + 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, + 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, + 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, + 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, + 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, + 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, + 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, + 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, + 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, + 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, + 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, + 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, + 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, + 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, + 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, + 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, + 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, + 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, + 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, + 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, + 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, + 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, + 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF +}; + +static PNG_CONST png_byte fourbppswaptable[256] = { + 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, + 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, + 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, + 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, + 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, + 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, + 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, + 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, + 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, + 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, + 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, + 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, + 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, + 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, + 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, + 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, + 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, + 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, + 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, + 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, + 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, + 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, + 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, + 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, + 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, + 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, + 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, + 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, + 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, + 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, + 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, + 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF +}; + +/* Swaps pixel packing order within bytes */ +void /* PRIVATE */ +png_do_packswap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_packswap"); + + if (row_info->bit_depth < 8) + { + png_bytep rp; + png_const_bytep end, table; + + end = row + row_info->rowbytes; + + if (row_info->bit_depth == 1) + table = onebppswaptable; + + else if (row_info->bit_depth == 2) + table = twobppswaptable; + + else if (row_info->bit_depth == 4) + table = fourbppswaptable; + + else + return; + + for (rp = row; rp < end; rp++) + *rp = table[*rp]; + } +} +#endif /* PACKSWAP || WRITE_PACKSWAP */ + +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +/* Remove a channel - this used to be 'png_do_strip_filler' but it used a + * somewhat weird combination of flags to determine what to do. All the calls + * to png_do_strip_filler are changed in 1.5.2 to call this instead with the + * correct arguments. + * + * The routine isn't general - the channel must be the channel at the start or + * end (not in the middle) of each pixel. + */ +void /* PRIVATE */ +png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start) +{ + png_bytep sp = row; /* source pointer */ + png_bytep dp = row; /* destination pointer */ + png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */ + + /* At the start sp will point to the first byte to copy and dp to where + * it is copied to. ep always points just beyond the end of the row, so + * the loop simply copies (channels-1) channels until sp reaches ep. + * + * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc. + * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc. + */ + + /* GA, GX, XG cases */ + if (row_info->channels == 2) + { + if (row_info->bit_depth == 8) + { + if (at_start != 0) /* Skip initial filler */ + ++sp; + else /* Skip initial channel and, for sp, the filler */ + sp += 2, ++dp; + + /* For a 1 pixel wide image there is nothing to do */ + while (sp < ep) + *dp++ = *sp, sp += 2; + + row_info->pixel_depth = 8; + } + + else if (row_info->bit_depth == 16) + { + if (at_start != 0) /* Skip initial filler */ + sp += 2; + else /* Skip initial channel and, for sp, the filler */ + sp += 4, dp += 2; + + while (sp < ep) + *dp++ = *sp++, *dp++ = *sp, sp += 3; + + row_info->pixel_depth = 16; + } + + else + return; /* bad bit depth */ + + row_info->channels = 1; + + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_GRAY; + } + + /* RGBA, RGBX, XRGB cases */ + else if (row_info->channels == 4) + { + if (row_info->bit_depth == 8) + { + if (at_start != 0) /* Skip initial filler */ + ++sp; + else /* Skip initial channels and, for sp, the filler */ + sp += 4, dp += 3; + + /* Note that the loop adds 3 to dp and 4 to sp each time. */ + while (sp < ep) + *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2; + + row_info->pixel_depth = 24; + } + + else if (row_info->bit_depth == 16) + { + if (at_start != 0) /* Skip initial filler */ + sp += 2; + else /* Skip initial channels and, for sp, the filler */ + sp += 8, dp += 6; + + while (sp < ep) + { + /* Copy 6 bytes, skip 2 */ + *dp++ = *sp++, *dp++ = *sp++; + *dp++ = *sp++, *dp++ = *sp++; + *dp++ = *sp++, *dp++ = *sp, sp += 3; + } + + row_info->pixel_depth = 48; + } + + else + return; /* bad bit depth */ + + row_info->channels = 3; + + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_RGB; + } + + else + return; /* The filler channel has gone already */ + + /* Fix the rowbytes value. */ + row_info->rowbytes = dp-row; +} +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Swaps red and blue bytes within a pixel */ +void /* PRIVATE */ +png_do_bgr(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_bgr"); + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_uint_32 row_width = row_info->width; + if (row_info->bit_depth == 8) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 3) + { + png_byte save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 4) + { + png_byte save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + } + +#ifdef PNG_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 6) + { + png_byte save = *rp; + *rp = *(rp + 4); + *(rp + 4) = save; + save = *(rp + 1); + *(rp + 1) = *(rp + 5); + *(rp + 5) = save; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 8) + { + png_byte save = *rp; + *rp = *(rp + 4); + *(rp + 4) = save; + save = *(rp + 1); + *(rp + 1) = *(rp + 5); + *(rp + 5) = save; + } + } + } +#endif + } +} +#endif /* READ_BGR || WRITE_BGR */ + +#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \ + defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED) +/* Added at libpng-1.5.10 */ +void /* PRIVATE */ +png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info) +{ + if (png_ptr->num_palette < (1 << row_info->bit_depth) && + png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */ + { + /* Calculations moved outside switch in an attempt to stop different + * compiler warnings. 'padding' is in *bits* within the last byte, it is + * an 'int' because pixel_depth becomes an 'int' in the expression below, + * and this calculation is used because it avoids warnings that other + * forms produced on either GCC or MSVC. + */ + int padding = (-row_info->pixel_depth * row_info->width) & 7; + png_bytep rp = png_ptr->row_buf + row_info->rowbytes; + + switch (row_info->bit_depth) + { + case 1: + { + /* in this case, all bytes must be 0 so we don't need + * to unpack the pixels except for the rightmost one. + */ + for (; rp > png_ptr->row_buf; rp--) + { + if ((*rp >> padding) != 0) + png_ptr->num_palette_max = 1; + padding = 0; + } + + break; + } + + case 2: + { + for (; rp > png_ptr->row_buf; rp--) + { + int i = ((*rp >> padding) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 2) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 4) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 6) & 0x03); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + padding = 0; + } + + break; + } + + case 4: + { + for (; rp > png_ptr->row_buf; rp--) + { + int i = ((*rp >> padding) & 0x0f); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + i = (((*rp >> padding) >> 4) & 0x0f); + + if (i > png_ptr->num_palette_max) + png_ptr->num_palette_max = i; + + padding = 0; + } + + break; + } + + case 8: + { + for (; rp > png_ptr->row_buf; rp--) + { + if (*rp > png_ptr->num_palette_max) + png_ptr->num_palette_max = (int) *rp; + } + + break; + } + + default: + break; + } + } +} +#endif /* CHECK_FOR_INVALID_INDEX */ + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +void PNGAPI +png_set_user_transform_info(png_structrp png_ptr, png_voidp + user_transform_ptr, int user_transform_depth, int user_transform_channels) +{ + png_debug(1, "in png_set_user_transform_info"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 && + (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0) + { + png_app_error(png_ptr, + "info change after png_start_read_image or png_read_update_info"); + return; + } +#endif + + png_ptr->user_transform_ptr = user_transform_ptr; + png_ptr->user_transform_depth = (png_byte)user_transform_depth; + png_ptr->user_transform_channels = (png_byte)user_transform_channels; +} +#endif + +/* This function returns a pointer to the user_transform_ptr associated with + * the user transform functions. The application should free any memory + * associated with this pointer before png_write_destroy and png_read_destroy + * are called. + */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +png_voidp PNGAPI +png_get_user_transform_ptr(png_const_structrp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return png_ptr->user_transform_ptr; +} +#endif + +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED +png_uint_32 PNGAPI +png_get_current_row_number(png_const_structrp png_ptr) +{ + /* See the comments in png.h - this is the sub-image row when reading an + * interlaced image. + */ + if (png_ptr != NULL) + return png_ptr->row_number; + + return PNG_UINT_32_MAX; /* help the app not to fail silently */ +} + +png_byte PNGAPI +png_get_current_pass_number(png_const_structrp png_ptr) +{ + if (png_ptr != NULL) + return png_ptr->pass; + return 8; /* invalid */ +} +#endif /* USER_TRANSFORM_INFO */ +#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */ +#endif /* READ || WRITE */ diff --git a/thirdparty/libpng/pngwio.c b/thirdparty/libpng/pngwio.c new file mode 100644 index 0000000000..586c03b721 --- /dev/null +++ b/thirdparty/libpng/pngwio.c @@ -0,0 +1,168 @@ + +/* pngwio.c - functions for data output + * + * Last changed in libpng 1.6.15 [November 20, 2014] + * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all output. Users who need + * special handling are expected to write functions that have the same + * arguments as these and perform similar functions, but that possibly + * use different output methods. Note that you shouldn't change these + * functions, but rather write replacement functions and then change + * them at run time with png_set_write_fn(...). + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +/* Write the data to whatever output you are using. The default routine + * writes to a file pointer. Note that this routine sometimes gets called + * with very small lengths, so you should implement some kind of simple + * buffering if you are using unbuffered writes. This should never be asked + * to write more than 64K on a 16-bit machine. + */ + +void /* PRIVATE */ +png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length) +{ + /* NOTE: write_data_fn must not change the buffer! */ + if (png_ptr->write_data_fn != NULL ) + (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data), + length); + + else + png_error(png_ptr, "Call to NULL write function"); +} + +#ifdef PNG_STDIO_SUPPORTED +/* This is the function that does the actual writing of data. If you are + * not writing to a standard C stream, you should create a replacement + * write_data function and use it at run time with png_set_write_fn(), rather + * than changing the library. + */ +void PNGCBAPI +png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + + if (png_ptr == NULL) + return; + + check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); + + if (check != length) + png_error(png_ptr, "Write Error"); +} +#endif + +/* This function is called to output any data pending writing (normally + * to disk). After png_flush is called, there should be no data pending + * writing in any buffers. + */ +#ifdef PNG_WRITE_FLUSH_SUPPORTED +void /* PRIVATE */ +png_flush(png_structrp png_ptr) +{ + if (png_ptr->output_flush_fn != NULL) + (*(png_ptr->output_flush_fn))(png_ptr); +} + +# ifdef PNG_STDIO_SUPPORTED +void PNGCBAPI +png_default_flush(png_structp png_ptr) +{ + png_FILE_p io_ptr; + + if (png_ptr == NULL) + return; + + io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr)); + fflush(io_ptr); +} +# endif +#endif + +/* This function allows the application to supply new output functions for + * libpng if standard C streams aren't being used. + * + * This function takes as its arguments: + * png_ptr - pointer to a png output data structure + * io_ptr - pointer to user supplied structure containing info about + * the output functions. May be NULL. + * write_data_fn - pointer to a new output function that takes as its + * arguments a pointer to a png_struct, a pointer to + * data to be written, and a 32-bit unsigned int that is + * the number of bytes to be written. The new write + * function should call png_error(png_ptr, "Error msg") + * to exit and output any fatal error messages. May be + * NULL, in which case libpng's default function will + * be used. + * flush_data_fn - pointer to a new flush function that takes as its + * arguments a pointer to a png_struct. After a call to + * the flush function, there should be no data in any buffers + * or pending transmission. If the output method doesn't do + * any buffering of output, a function prototype must still be + * supplied although it doesn't have to do anything. If + * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile + * time, output_flush_fn will be ignored, although it must be + * supplied for compatibility. May be NULL, in which case + * libpng's default function will be used, if + * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not + * a good idea if io_ptr does not point to a standard + * *FILE structure. + */ +void PNGAPI +png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = io_ptr; + +#ifdef PNG_STDIO_SUPPORTED + if (write_data_fn != NULL) + png_ptr->write_data_fn = write_data_fn; + + else + png_ptr->write_data_fn = png_default_write_data; +#else + png_ptr->write_data_fn = write_data_fn; +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_STDIO_SUPPORTED + + if (output_flush_fn != NULL) + png_ptr->output_flush_fn = output_flush_fn; + + else + png_ptr->output_flush_fn = png_default_flush; + +# else + png_ptr->output_flush_fn = output_flush_fn; +# endif +#else + PNG_UNUSED(output_flush_fn) +#endif /* WRITE_FLUSH */ + +#ifdef PNG_READ_SUPPORTED + /* It is an error to read while writing a png file */ + if (png_ptr->read_data_fn != NULL) + { + png_ptr->read_data_fn = NULL; + + png_warning(png_ptr, + "Can't set both read_data_fn and write_data_fn in the" + " same structure"); + } +#endif +} +#endif /* WRITE */ diff --git a/thirdparty/libpng/pngwrite.c b/thirdparty/libpng/pngwrite.c new file mode 100644 index 0000000000..181a899438 --- /dev/null +++ b/thirdparty/libpng/pngwrite.c @@ -0,0 +1,2383 @@ + +/* pngwrite.c - general routines to write a PNG file + * + * Last changed in libpng 1.6.19 [November 12, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +# include <errno.h> +#endif /* SIMPLIFIED_WRITE_STDIO */ + +#ifdef PNG_WRITE_SUPPORTED + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED +/* Write out all the unknown chunks for the current given location */ +static void +write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr, + unsigned int where) +{ + if (info_ptr->unknown_chunks_num != 0) + { + png_const_unknown_chunkp up; + + png_debug(5, "writing extra chunks"); + + for (up = info_ptr->unknown_chunks; + up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; + ++up) + if ((up->location & where) != 0) + { + /* If per-chunk unknown chunk handling is enabled use it, otherwise + * just write the chunks the application has set. + */ +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + int keep = png_handle_as_unknown(png_ptr, up->name); + + /* NOTE: this code is radically different from the read side in the + * matter of handling an ancillary unknown chunk. In the read side + * the default behavior is to discard it, in the code below the default + * behavior is to write it. Critical chunks are, however, only + * written if explicitly listed or if the default is set to write all + * unknown chunks. + * + * The default handling is also slightly weird - it is not possible to + * stop the writing of all unsafe-to-copy chunks! + * + * TODO: REVIEW: this would seem to be a bug. + */ + if (keep != PNG_HANDLE_CHUNK_NEVER && + ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ || + keep == PNG_HANDLE_CHUNK_ALWAYS || + (keep == PNG_HANDLE_CHUNK_AS_DEFAULT && + png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS))) +#endif + { + /* TODO: review, what is wrong with a zero length unknown chunk? */ + if (up->size == 0) + png_warning(png_ptr, "Writing zero-length unknown chunk"); + + png_write_chunk(png_ptr, up->name, up->data, up->size); + } + } + } +} +#endif /* WRITE_UNKNOWN_CHUNKS */ + +/* Writes all the PNG information. This is the suggested way to use the + * library. If you have a new chunk to add, make a function to write it, + * and put it in the correct location here. If you want the chunk written + * after the image data, put it in png_write_end(). I strongly encourage + * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing + * the chunk, as that will keep the code from breaking if you want to just + * write a plain PNG file. If you have long comments, I suggest writing + * them in png_write_end(), and compressing them. + */ +void PNGAPI +png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr) +{ + png_debug(1, "in png_write_info_before_PLTE"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) + { + /* Write PNG signature */ + png_write_sig(png_ptr); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \ + png_ptr->mng_features_permitted != 0) + { + png_warning(png_ptr, + "MNG features are not allowed in a PNG datastream"); + png_ptr->mng_features_permitted = 0; + } +#endif + + /* Write IHDR information. */ + png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type, + info_ptr->filter_type, +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + info_ptr->interlace_type +#else + 0 +#endif + ); + + /* The rest of these check to see if the valid field has the appropriate + * flag set, and if it does, writes the chunk. + * + * 1.6.0: COLORSPACE support controls the writing of these chunks too, and + * the chunks will be written if the WRITE routine is there and + * information * is available in the COLORSPACE. (See + * png_colorspace_sync_info in png.c for where the valid flags get set.) + * + * Under certain circumstances the colorspace can be invalidated without + * syncing the info_struct 'valid' flags; this happens if libpng detects + * an error and calls png_error while the color space is being set, yet + * the application continues writing the PNG. So check the 'invalid' + * flag here too. + */ +#ifdef PNG_GAMMA_SUPPORTED +# ifdef PNG_WRITE_gAMA_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 && + (info_ptr->valid & PNG_INFO_gAMA) != 0) + png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma); +# endif +#endif + +#ifdef PNG_COLORSPACE_SUPPORTED + /* Write only one of sRGB or an ICC profile. If a profile was supplied + * and it matches one of the known sRGB ones issue a warning. + */ +# ifdef PNG_WRITE_iCCP_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->valid & PNG_INFO_iCCP) != 0) + { +# ifdef PNG_WRITE_sRGB_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sRGB) != 0) + png_app_warning(png_ptr, + "profile matches sRGB but writing iCCP instead"); +# endif + + png_write_iCCP(png_ptr, info_ptr->iccp_name, + info_ptr->iccp_profile); + } +# ifdef PNG_WRITE_sRGB_SUPPORTED + else +# endif +# endif + +# ifdef PNG_WRITE_sRGB_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->valid & PNG_INFO_sRGB) != 0) + png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent); +# endif /* WRITE_sRGB */ +#endif /* COLORSPACE */ + +#ifdef PNG_WRITE_sBIT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); +#endif + +#ifdef PNG_COLORSPACE_SUPPORTED +# ifdef PNG_WRITE_cHRM_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 && + (info_ptr->valid & PNG_INFO_cHRM) != 0) + png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy); +# endif +#endif + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR); +#endif + + png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE; + } +} + +void PNGAPI +png_write_info(png_structrp png_ptr, png_const_inforp info_ptr) +{ +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) + int i; +#endif + + png_debug(1, "in png_write_info"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_write_info_before_PLTE(png_ptr, info_ptr); + + if ((info_ptr->valid & PNG_INFO_PLTE) != 0) + png_write_PLTE(png_ptr, info_ptr->palette, + (png_uint_32)info_ptr->num_palette); + + else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_error(png_ptr, "Valid palette required for paletted images"); + +#ifdef PNG_WRITE_tRNS_SUPPORTED + if ((info_ptr->valid & PNG_INFO_tRNS) !=0) + { +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + /* Invert the alpha channel (in tRNS) */ + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 && + info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + int j, jend; + + jend = info_ptr->num_trans; + if (jend > PNG_MAX_PALETTE_LENGTH) + jend = PNG_MAX_PALETTE_LENGTH; + + for (j = 0; j<jend; ++j) + info_ptr->trans_alpha[j] = + (png_byte)(255 - info_ptr->trans_alpha[j]); + } +#endif + png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color), + info_ptr->num_trans, info_ptr->color_type); + } +#endif +#ifdef PNG_WRITE_bKGD_SUPPORTED + if ((info_ptr->valid & PNG_INFO_bKGD) != 0) + png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type); +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED + if ((info_ptr->valid & PNG_INFO_hIST) != 0) + png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED + if ((info_ptr->valid & PNG_INFO_oFFs) != 0) + png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, + info_ptr->offset_unit_type); +#endif + +#ifdef PNG_WRITE_pCAL_SUPPORTED + if ((info_ptr->valid & PNG_INFO_pCAL) != 0) + png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0, + info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams, + info_ptr->pcal_units, info_ptr->pcal_params); +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sCAL) != 0) + png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit, + info_ptr->scal_s_width, info_ptr->scal_s_height); +#endif /* sCAL */ + +#ifdef PNG_WRITE_pHYs_SUPPORTED + if ((info_ptr->valid & PNG_INFO_pHYs) != 0) + png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, + info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); +#endif /* pHYs */ + +#ifdef PNG_WRITE_tIME_SUPPORTED + if ((info_ptr->valid & PNG_INFO_tIME) != 0) + { + png_write_tIME(png_ptr, &(info_ptr->mod_time)); + png_ptr->mode |= PNG_WROTE_tIME; + } +#endif /* tIME */ + +#ifdef PNG_WRITE_sPLT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sPLT) != 0) + for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) + png_write_sPLT(png_ptr, info_ptr->splt_palettes + i); +#endif /* sPLT */ + +#ifdef PNG_WRITE_TEXT_SUPPORTED + /* Check to see if we need to write text chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing header text chunk %d, type %d", i, + info_ptr->text[i].compression); + /* An internationalized chunk? */ + if (info_ptr->text[i].compression > 0) + { +#ifdef PNG_WRITE_iTXt_SUPPORTED + /* Write international chunk */ + png_write_iTXt(png_ptr, + info_ptr->text[i].compression, + info_ptr->text[i].key, + info_ptr->text[i].lang, + info_ptr->text[i].lang_key, + info_ptr->text[i].text); + /* Mark this chunk as written */ + if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + else + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write international text"); +#endif + } + + /* If we want a compressed text chunk */ + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt) + { +#ifdef PNG_WRITE_zTXt_SUPPORTED + /* Write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].compression); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write compressed text"); +#endif + } + + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#ifdef PNG_WRITE_tEXt_SUPPORTED + /* Write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, + 0); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; +#else + /* Can't get here */ + png_warning(png_ptr, "Unable to write uncompressed text"); +#endif + } + } +#endif /* tEXt */ + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE); +#endif +} + +/* Writes the end of the PNG file. If you don't want to write comments or + * time information, you can pass NULL for info. If you already wrote these + * in png_write_info(), do not write them again here. If you have long + * comments, I suggest writing them here, and compressing them. + */ +void PNGAPI +png_write_end(png_structrp png_ptr, png_inforp info_ptr) +{ + png_debug(1, "in png_write_end"); + + if (png_ptr == NULL) + return; + + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) + png_error(png_ptr, "No IDATs written into file"); + +#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED + if (png_ptr->num_palette_max > png_ptr->num_palette) + png_benign_error(png_ptr, "Wrote palette index exceeding num_palette"); +#endif + + /* See if user wants us to write information chunks */ + if (info_ptr != NULL) + { +#ifdef PNG_WRITE_TEXT_SUPPORTED + int i; /* local index variable */ +#endif +#ifdef PNG_WRITE_tIME_SUPPORTED + /* Check to see if user has supplied a time chunk */ + if ((info_ptr->valid & PNG_INFO_tIME) != 0 && + (png_ptr->mode & PNG_WROTE_tIME) == 0) + png_write_tIME(png_ptr, &(info_ptr->mod_time)); + +#endif +#ifdef PNG_WRITE_TEXT_SUPPORTED + /* Loop through comment chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing trailer text chunk %d, type %d", i, + info_ptr->text[i].compression); + /* An internationalized chunk? */ + if (info_ptr->text[i].compression > 0) + { +#ifdef PNG_WRITE_iTXt_SUPPORTED + /* Write international chunk */ + png_write_iTXt(png_ptr, + info_ptr->text[i].compression, + info_ptr->text[i].key, + info_ptr->text[i].lang, + info_ptr->text[i].lang_key, + info_ptr->text[i].text); + /* Mark this chunk as written */ + if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + else + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write international text"); +#endif + } + + else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt) + { +#ifdef PNG_WRITE_zTXt_SUPPORTED + /* Write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].compression); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; +#else + png_warning(png_ptr, "Unable to write compressed text"); +#endif + } + + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#ifdef PNG_WRITE_tEXt_SUPPORTED + /* Write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, 0); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; +#else + png_warning(png_ptr, "Unable to write uncompressed text"); +#endif + } + } +#endif +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT); +#endif + } + + png_ptr->mode |= PNG_AFTER_IDAT; + + /* Write end of PNG file */ + png_write_IEND(png_ptr); + + /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03, + * and restored again in libpng-1.2.30, may cause some applications that + * do not set png_ptr->output_flush_fn to crash. If your application + * experiences a problem, please try building libpng with + * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to + * png-mng-implement at lists.sf.net . + */ +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED + png_flush(png_ptr); +# endif +#endif +} + +#ifdef PNG_CONVERT_tIME_SUPPORTED +void PNGAPI +png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime) +{ + png_debug(1, "in png_convert_from_struct_tm"); + + ptime->year = (png_uint_16)(1900 + ttime->tm_year); + ptime->month = (png_byte)(ttime->tm_mon + 1); + ptime->day = (png_byte)ttime->tm_mday; + ptime->hour = (png_byte)ttime->tm_hour; + ptime->minute = (png_byte)ttime->tm_min; + ptime->second = (png_byte)ttime->tm_sec; +} + +void PNGAPI +png_convert_from_time_t(png_timep ptime, time_t ttime) +{ + struct tm *tbuf; + + png_debug(1, "in png_convert_from_time_t"); + + tbuf = gmtime(&ttime); + png_convert_from_struct_tm(ptime, tbuf); +} +#endif + +/* Initialize png_ptr structure, and allocate any memory needed */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) +{ +#ifndef PNG_USER_MEM_SUPPORTED + png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, NULL, NULL, NULL); +#else + return png_create_write_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, NULL, NULL, NULL); +} + +/* Alternate initialize png_ptr structure, and allocate any memory needed */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ + png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); +#endif /* USER_MEM */ + if (png_ptr != NULL) + { + /* Set the zlib control values to defaults; they can be overridden by the + * application after the struct has been created. + */ + png_ptr->zbuffer_size = PNG_ZBUF_SIZE; + + /* The 'zlib_strategy' setting is irrelevant because png_default_claim in + * pngwutil.c defaults it according to whether or not filters will be + * used, and ignores this setting. + */ + png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY; + png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION; + png_ptr->zlib_mem_level = 8; + png_ptr->zlib_window_bits = 15; + png_ptr->zlib_method = 8; + +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED + png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY; + png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION; + png_ptr->zlib_text_mem_level = 8; + png_ptr->zlib_text_window_bits = 15; + png_ptr->zlib_text_method = 8; +#endif /* WRITE_COMPRESSED_TEXT */ + + /* This is a highly dubious configuration option; by default it is off, + * but it may be appropriate for private builds that are testing + * extensions not conformant to the current specification, or of + * applications that must not fail to write at all costs! + */ +#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED + /* In stable builds only warn if an application error can be completely + * handled. + */ + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; +#endif + + /* App warnings are warnings in release (or release candidate) builds but + * are errors during development. + */ +#if PNG_RELEASE_BUILD + png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; +#endif + + /* TODO: delay this, it can be done in png_init_io() (if the app doesn't + * do it itself) avoiding setting the default function if it is not + * required. + */ + png_set_write_fn(png_ptr, NULL, NULL, NULL); + } + + return png_ptr; +} + + +/* Write a few rows of image data. If the image is interlaced, + * either you will have to write the 7 sub images, or, if you + * have called png_set_interlace_handling(), you will have to + * "write" the image seven times. + */ +void PNGAPI +png_write_rows(png_structrp png_ptr, png_bytepp row, + png_uint_32 num_rows) +{ + png_uint_32 i; /* row counter */ + png_bytepp rp; /* row pointer */ + + png_debug(1, "in png_write_rows"); + + if (png_ptr == NULL) + return; + + /* Loop through the rows */ + for (i = 0, rp = row; i < num_rows; i++, rp++) + { + png_write_row(png_ptr, *rp); + } +} + +/* Write the image. You only need to call this function once, even + * if you are writing an interlaced image. + */ +void PNGAPI +png_write_image(png_structrp png_ptr, png_bytepp image) +{ + png_uint_32 i; /* row index */ + int pass, num_pass; /* pass variables */ + png_bytepp rp; /* points to current row */ + + if (png_ptr == NULL) + return; + + png_debug(1, "in png_write_image"); + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Initialize interlace handling. If image is not interlaced, + * this will set pass to 1 + */ + num_pass = png_set_interlace_handling(png_ptr); +#else + num_pass = 1; +#endif + /* Loop through passes */ + for (pass = 0; pass < num_pass; pass++) + { + /* Loop through image */ + for (i = 0, rp = image; i < png_ptr->height; i++, rp++) + { + png_write_row(png_ptr, *rp); + } + } +} + +#ifdef PNG_MNG_FEATURES_SUPPORTED +/* Performs intrapixel differencing */ +static void +png_do_write_intrapixel(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_intrapixel"); + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + int bytes_per_pixel; + png_uint_32 row_width = row_info->width; + if (row_info->bit_depth == 8) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 3; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 4; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + *(rp) = (png_byte)(*rp - *(rp + 1)); + *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 6; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 8; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); + png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); + png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); + *(rp ) = (png_byte)(red >> 8); + *(rp + 1) = (png_byte)red; + *(rp + 4) = (png_byte)(blue >> 8); + *(rp + 5) = (png_byte)blue; + } + } +#endif /* WRITE_16BIT */ + } +} +#endif /* MNG_FEATURES */ + +/* Called by user to write a row of image data */ +void PNGAPI +png_write_row(png_structrp png_ptr, png_const_bytep row) +{ + /* 1.5.6: moved from png_struct to be a local structure: */ + png_row_info row_info; + + if (png_ptr == NULL) + return; + + png_debug2(1, "in png_write_row (row %u, pass %d)", + png_ptr->row_number, png_ptr->pass); + + /* Initialize transformations and other stuff if first time */ + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + /* Make sure we wrote the header info */ + if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) + png_error(png_ptr, + "png_write_info was never called before png_write_row"); + + /* Check for transforms that have been set but were defined out */ +#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED) + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED) + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined"); +#endif +#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ + defined(PNG_READ_PACKSWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_warning(png_ptr, + "PNG_WRITE_PACKSWAP_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED) + if ((png_ptr->transformations & PNG_PACK) != 0) + png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED) + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED) + if ((png_ptr->transformations & PNG_BGR) != 0) + png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED) + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined"); +#endif + + png_write_start_row(png_ptr); + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced and not interested in row, return */ + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + switch (png_ptr->pass) + { + case 0: + if ((png_ptr->row_number & 0x07) != 0) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 1: + if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 2: + if ((png_ptr->row_number & 0x07) != 4) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 3: + if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 4: + if ((png_ptr->row_number & 0x03) != 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 5: + if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 6: + if ((png_ptr->row_number & 0x01) == 0) + { + png_write_finish_row(png_ptr); + return; + } + break; + + default: /* error: ignore it */ + break; + } + } +#endif + + /* Set up row info for transformations */ + row_info.color_type = png_ptr->color_type; + row_info.width = png_ptr->usr_width; + row_info.channels = png_ptr->usr_channels; + row_info.bit_depth = png_ptr->usr_bit_depth; + row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels); + row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); + + png_debug1(3, "row_info->color_type = %d", row_info.color_type); + png_debug1(3, "row_info->width = %u", row_info.width); + png_debug1(3, "row_info->channels = %d", row_info.channels); + png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth); + png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth); + png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); + + /* Copy user's row into buffer, leaving room for filter byte. */ + memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Handle interlacing */ + if (png_ptr->interlaced && png_ptr->pass < 6 && + (png_ptr->transformations & PNG_INTERLACE) != 0) + { + png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); + /* This should always get caught above, but still ... */ + if (row_info.width == 0) + { + png_write_finish_row(png_ptr); + return; + } + } +#endif + +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED + /* Handle other transformations */ + if (png_ptr->transformations != 0) + png_do_write_transformations(png_ptr, &row_info); +#endif + + /* At this point the row_info pixel depth must match the 'transformed' depth, + * which is also the output depth. + */ + if (row_info.pixel_depth != png_ptr->pixel_depth || + row_info.pixel_depth != png_ptr->transformed_pixel_depth) + png_error(png_ptr, "internal write transform logic error"); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) + { + /* Intrapixel differencing */ + png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1); + } +#endif + +/* Added at libpng-1.5.10 */ +#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Check for out-of-range palette index */ + if (row_info.color_type == PNG_COLOR_TYPE_PALETTE && + png_ptr->num_palette_max >= 0) + png_do_check_palette_indexes(png_ptr, &row_info); +#endif + + /* Find a filter if necessary, filter the row and write it out. */ + png_write_find_filter(png_ptr, &row_info); + + if (png_ptr->write_row_fn != NULL) + (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); +} + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +/* Set the automatic flush interval or 0 to turn flushing off */ +void PNGAPI +png_set_flush(png_structrp png_ptr, int nrows) +{ + png_debug(1, "in png_set_flush"); + + if (png_ptr == NULL) + return; + + png_ptr->flush_dist = (nrows < 0 ? 0 : nrows); +} + +/* Flush the current output buffers now */ +void PNGAPI +png_write_flush(png_structrp png_ptr) +{ + png_debug(1, "in png_write_flush"); + + if (png_ptr == NULL) + return; + + /* We have already written out all of the data */ + if (png_ptr->row_number >= png_ptr->num_rows) + return; + + png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH); + png_ptr->flush_rows = 0; + png_flush(png_ptr); +} +#endif /* WRITE_FLUSH */ + +/* Free any memory used in png_ptr struct without freeing the struct itself. */ +static void +png_write_destroy(png_structrp png_ptr) +{ + png_debug(1, "in png_write_destroy"); + + /* Free any memory zlib uses */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) + deflateEnd(&png_ptr->zstream); + + /* Free our memory. png_free checks NULL for us. */ + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); + png_free(png_ptr, png_ptr->row_buf); + png_ptr->row_buf = NULL; +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_free(png_ptr, png_ptr->prev_row); + png_free(png_ptr, png_ptr->try_row); + png_free(png_ptr, png_ptr->tst_row); + png_ptr->prev_row = NULL; + png_ptr->try_row = NULL; + png_ptr->tst_row = NULL; +#endif + +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->chunk_list = NULL; +#endif + + /* The error handling and memory handling information is left intact at this + * point: the jmp_buf may still have to be freed. See png_destroy_png_struct + * for how this happens. + */ +} + +/* Free all memory used by the write. + * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for + * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free + * the passed in info_structs but it would quietly fail to free any of the data + * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it + * has no png_ptr.) + */ +void PNGAPI +png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) +{ + png_debug(1, "in png_destroy_write_struct"); + + if (png_ptr_ptr != NULL) + { + png_structrp png_ptr = *png_ptr_ptr; + + if (png_ptr != NULL) /* added in libpng 1.6.0 */ + { + png_destroy_info_struct(png_ptr, info_ptr_ptr); + + *png_ptr_ptr = NULL; + png_write_destroy(png_ptr); + png_destroy_png_struct(png_ptr); + } + } +} + +/* Allow the application to select one or more row filters to use. */ +void PNGAPI +png_set_filter(png_structrp png_ptr, int method, int filters) +{ + png_debug(1, "in png_set_filter"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + (method == PNG_INTRAPIXEL_DIFFERENCING)) + method = PNG_FILTER_TYPE_BASE; + +#endif + if (method == PNG_FILTER_TYPE_BASE) + { + switch (filters & (PNG_ALL_FILTERS | 0x07)) + { +#ifdef PNG_WRITE_FILTER_SUPPORTED + case 5: + case 6: + case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); + /* FALL THROUGH */ +#endif /* WRITE_FILTER */ + case PNG_FILTER_VALUE_NONE: + png_ptr->do_filter = PNG_FILTER_NONE; break; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + case PNG_FILTER_VALUE_SUB: + png_ptr->do_filter = PNG_FILTER_SUB; break; + + case PNG_FILTER_VALUE_UP: + png_ptr->do_filter = PNG_FILTER_UP; break; + + case PNG_FILTER_VALUE_AVG: + png_ptr->do_filter = PNG_FILTER_AVG; break; + + case PNG_FILTER_VALUE_PAETH: + png_ptr->do_filter = PNG_FILTER_PAETH; break; + + default: + png_ptr->do_filter = (png_byte)filters; break; +#else + default: + png_app_error(png_ptr, "Unknown row filter for method 0"); +#endif /* WRITE_FILTER */ + } + +#ifdef PNG_WRITE_FILTER_SUPPORTED + /* If we have allocated the row_buf, this means we have already started + * with the image and we should have allocated all of the filter buffers + * that have been selected. If prev_row isn't already allocated, then + * it is too late to start using the filters that need it, since we + * will be missing the data in the previous row. If an application + * wants to start and stop using particular filters during compression, + * it should start out with all of the filters, and then remove them + * or add them back after the start of compression. + * + * NOTE: this is a nasty constraint on the code, because it means that the + * prev_row buffer must be maintained even if there are currently no + * 'prev_row' requiring filters active. + */ + if (png_ptr->row_buf != NULL) + { + int num_filters; + png_alloc_size_t buf_size; + + /* Repeat the checks in png_write_start_row; 1 pixel high or wide + * images cannot benefit from certain filters. If this isn't done here + * the check below will fire on 1 pixel high images. + */ + if (png_ptr->height == 1) + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (png_ptr->width == 1) + filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0 + && png_ptr->prev_row == NULL) + { + /* This is the error case, however it is benign - the previous row + * is not available so the filter can't be used. Just warn here. + */ + png_app_warning(png_ptr, + "png_set_filter: UP/AVG/PAETH cannot be added after start"); + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); + } + + num_filters = 0; + + if (filters & PNG_FILTER_SUB) + num_filters++; + + if (filters & PNG_FILTER_UP) + num_filters++; + + if (filters & PNG_FILTER_AVG) + num_filters++; + + if (filters & PNG_FILTER_PAETH) + num_filters++; + + /* Allocate needed row buffers if they have not already been + * allocated. + */ + buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth, + png_ptr->width) + 1; + + if (png_ptr->try_row == NULL) + png_ptr->try_row = png_voidcast(png_bytep, + png_malloc(png_ptr, buf_size)); + + if (num_filters > 1) + { + if (png_ptr->tst_row == NULL) + png_ptr->tst_row = png_voidcast(png_bytep, + png_malloc(png_ptr, buf_size)); + } + } + png_ptr->do_filter = (png_byte)filters; +#endif + } + else + png_error(png_ptr, "Unknown custom filter method"); +} + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ +/* Provide floating and fixed point APIs */ +#ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, + int num_weights, png_const_doublep filter_weights, + png_const_doublep filter_costs) +{ + PNG_UNUSED(png_ptr) + PNG_UNUSED(heuristic_method) + PNG_UNUSED(num_weights) + PNG_UNUSED(filter_weights) + PNG_UNUSED(filter_costs) +} +#endif /* FLOATING_POINT */ + +#ifdef PNG_FIXED_POINT_SUPPORTED +void PNGAPI +png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method, + int num_weights, png_const_fixed_point_p filter_weights, + png_const_fixed_point_p filter_costs) +{ + PNG_UNUSED(png_ptr) + PNG_UNUSED(heuristic_method) + PNG_UNUSED(num_weights) + PNG_UNUSED(filter_weights) + PNG_UNUSED(filter_costs) +} +#endif /* FIXED_POINT */ +#endif /* WRITE_WEIGHTED_FILTER */ + +#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED +void PNGAPI +png_set_compression_level(png_structrp png_ptr, int level) +{ + png_debug(1, "in png_set_compression_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_level = level; +} + +void PNGAPI +png_set_compression_mem_level(png_structrp png_ptr, int mem_level) +{ + png_debug(1, "in png_set_compression_mem_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_mem_level = mem_level; +} + +void PNGAPI +png_set_compression_strategy(png_structrp png_ptr, int strategy) +{ + png_debug(1, "in png_set_compression_strategy"); + + if (png_ptr == NULL) + return; + + /* The flag setting here prevents the libpng dynamic selection of strategy. + */ + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; + png_ptr->zlib_strategy = strategy; +} + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +void PNGAPI +png_set_compression_window_bits(png_structrp png_ptr, int window_bits) +{ + if (png_ptr == NULL) + return; + + /* Prior to 1.6.0 this would warn but then set the window_bits value. This + * meant that negative window bits values could be selected that would cause + * libpng to write a non-standard PNG file with raw deflate or gzip + * compressed IDAT or ancillary chunks. Such files can be read and there is + * no warning on read, so this seems like a very bad idea. + */ + if (window_bits > 15) + { + png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + window_bits = 15; + } + + else if (window_bits < 8) + { + png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + window_bits = 8; + } + + png_ptr->zlib_window_bits = window_bits; +} + +void PNGAPI +png_set_compression_method(png_structrp png_ptr, int method) +{ + png_debug(1, "in png_set_compression_method"); + + if (png_ptr == NULL) + return; + + /* This would produce an invalid PNG file if it worked, but it doesn't and + * deflate will fault it, so it is harmless to just warn here. + */ + if (method != 8) + png_warning(png_ptr, "Only compression method 8 is supported by PNG"); + + png_ptr->zlib_method = method; +} +#endif /* WRITE_CUSTOMIZE_COMPRESSION */ + +/* The following were added to libpng-1.5.4 */ +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED +void PNGAPI +png_set_text_compression_level(png_structrp png_ptr, int level) +{ + png_debug(1, "in png_set_text_compression_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_text_level = level; +} + +void PNGAPI +png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level) +{ + png_debug(1, "in png_set_text_compression_mem_level"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_text_mem_level = mem_level; +} + +void PNGAPI +png_set_text_compression_strategy(png_structrp png_ptr, int strategy) +{ + png_debug(1, "in png_set_text_compression_strategy"); + + if (png_ptr == NULL) + return; + + png_ptr->zlib_text_strategy = strategy; +} + +/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a + * smaller value of window_bits if it can do so safely. + */ +void PNGAPI +png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits) +{ + if (png_ptr == NULL) + return; + + if (window_bits > 15) + { + png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + window_bits = 15; + } + + else if (window_bits < 8) + { + png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + window_bits = 8; + } + + png_ptr->zlib_text_window_bits = window_bits; +} + +void PNGAPI +png_set_text_compression_method(png_structrp png_ptr, int method) +{ + png_debug(1, "in png_set_text_compression_method"); + + if (png_ptr == NULL) + return; + + if (method != 8) + png_warning(png_ptr, "Only compression method 8 is supported by PNG"); + + png_ptr->zlib_text_method = method; +} +#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ +/* end of API added to libpng-1.5.4 */ + +void PNGAPI +png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->write_row_fn = write_row_fn; +} + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +void PNGAPI +png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr + write_user_transform_fn) +{ + png_debug(1, "in png_set_write_user_transform_fn"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->write_user_transform_fn = write_user_transform_fn; +} +#endif + + +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_write_png(png_structrp png_ptr, png_inforp info_ptr, + int transforms, voidp params) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + if ((info_ptr->valid & PNG_INFO_IDAT) == 0) + { + png_app_error(png_ptr, "no rows for png_write_image to write"); + return; + } + + /* Write the file header information. */ + png_write_info(png_ptr, info_ptr); + + /* ------ these transformations don't touch the info structure ------- */ + + /* Invert monochrome pixels */ + if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) +#ifdef PNG_WRITE_INVERT_SUPPORTED + png_set_invert_mono(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); +#endif + + /* Shift the pixels up to a legal bit depth and fill in + * as appropriate to correctly scale the image. + */ + if ((transforms & PNG_TRANSFORM_SHIFT) != 0) +#ifdef PNG_WRITE_SHIFT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_set_shift(png_ptr, &info_ptr->sig_bit); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); +#endif + + /* Pack pixels into bytes */ + if ((transforms & PNG_TRANSFORM_PACKING) != 0) +#ifdef PNG_WRITE_PACK_SUPPORTED + png_set_packing(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); +#endif + + /* Swap location of alpha bytes from ARGB to RGBA */ + if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED + png_set_swap_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); +#endif + + /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into + * RGB, note that the code expects the input color type to be G or RGB; no + * alpha channel. + */ + if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER| + PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0) + { +#ifdef PNG_WRITE_FILLER_SUPPORTED + if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0) + { + if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) + png_app_error(png_ptr, + "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported"); + + /* Continue if ignored - this is the pre-1.6.10 behavior */ + png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); + } + + else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported"); +#endif + } + + /* Flip BGR pixels to RGB */ + if ((transforms & PNG_TRANSFORM_BGR) != 0) +#ifdef PNG_WRITE_BGR_SUPPORTED + png_set_bgr(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); +#endif + + /* Swap bytes of 16-bit files to most significant byte first */ + if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) +#ifdef PNG_WRITE_SWAP_SUPPORTED + png_set_swap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); +#endif + + /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */ + if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED + png_set_packswap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); +#endif + + /* Invert the alpha channel from opacity to transparency */ + if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + png_set_invert_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); +#endif + + /* ----------------------- end of transformations ------------------- */ + + /* Write the bits */ + png_write_image(png_ptr, info_ptr->row_pointers); + + /* It is REQUIRED to call this to finish writing the rest of the file */ + png_write_end(png_ptr, info_ptr); + + PNG_UNUSED(params) +} +#endif + + +#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED +/* Initialize the write structure - general purpose utility. */ +static int +png_image_write_init(png_imagep image) +{ + png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image, + png_safe_error, png_safe_warning); + + if (png_ptr != NULL) + { + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (info_ptr != NULL) + { + png_controlp control = png_voidcast(png_controlp, + png_malloc_warn(png_ptr, (sizeof *control))); + + if (control != NULL) + { + memset(control, 0, (sizeof *control)); + + control->png_ptr = png_ptr; + control->info_ptr = info_ptr; + control->for_write = 1; + + image->opaque = control; + return 1; + } + + /* Error clean up */ + png_destroy_info_struct(png_ptr, &info_ptr); + } + + png_destroy_write_struct(&png_ptr, NULL); + } + + return png_image_error(image, "png_image_write_: out of memory"); +} + +/* Arguments to png_image_write_main: */ +typedef struct +{ + /* Arguments: */ + png_imagep image; + png_const_voidp buffer; + png_int_32 row_stride; + png_const_voidp colormap; + int convert_to_8bit; + /* Local variables: */ + png_const_voidp first_row; + ptrdiff_t row_bytes; + png_voidp local_row; + /* Byte count for memory writing */ + png_bytep memory; + png_alloc_size_t memory_bytes; /* not used for STDIO */ + png_alloc_size_t output_bytes; /* running total */ +} png_image_write_control; + +/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to + * do any necessary byte swapping. The component order is defined by the + * png_image format value. + */ +static int +png_write_image_16bit(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + + png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, + display->first_row); + png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row); + png_uint_16p row_end; + const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; + int aindex = 0; + png_uint_32 y = image->height; + + if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + { +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + aindex = -1; + ++input_row; /* To point to the first component */ + ++output_row; + } + else + aindex = channels; +# else + aindex = channels; +# endif + } + + else + png_error(png_ptr, "png_write_image: internal call error"); + + /* Work out the output row end and count over this, note that the increment + * above to 'row' means that row_end can actually be beyond the end of the + * row; this is correct. + */ + row_end = output_row + image->width * (channels+1); + + while (y-- > 0) + { + png_const_uint_16p in_ptr = input_row; + png_uint_16p out_ptr = output_row; + + while (out_ptr < row_end) + { + const png_uint_16 alpha = in_ptr[aindex]; + png_uint_32 reciprocal = 0; + int c; + + out_ptr[aindex] = alpha; + + /* Calculate a reciprocal. The correct calculation is simply + * component/alpha*65535 << 15. (I.e. 15 bits of precision); this + * allows correct rounding by adding .5 before the shift. 'reciprocal' + * is only initialized when required. + */ + if (alpha > 0 && alpha < 65535) + reciprocal = ((0xffff<<15)+(alpha>>1))/alpha; + + c = channels; + do /* always at least one channel */ + { + png_uint_16 component = *in_ptr++; + + /* The following gives 65535 for an alpha of 0, which is fine, + * otherwise if 0/0 is represented as some other value there is more + * likely to be a discontinuity which will probably damage + * compression when moving from a fully transparent area to a + * nearly transparent one. (The assumption here is that opaque + * areas tend not to be 0 intensity.) + */ + if (component >= alpha) + component = 65535; + + /* component<alpha, so component/alpha is less than one and + * component*reciprocal is less than 2^31. + */ + else if (component > 0 && alpha < 65535) + { + png_uint_32 calc = component * reciprocal; + calc += 16384; /* round to nearest */ + component = (png_uint_16)(calc >> 15); + } + + *out_ptr++ = component; + } + while (--c > 0); + + /* Skip to next component (skip the intervening alpha channel) */ + ++in_ptr; + ++out_ptr; + } + + png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row)); + input_row += display->row_bytes/(sizeof (png_uint_16)); + } + + return 1; +} + +/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel + * is present it must be removed from the components, the components are then + * written in sRGB encoding. No components are added or removed. + * + * Calculate an alpha reciprocal to reverse pre-multiplication. As above the + * calculation can be done to 15 bits of accuracy; however, the output needs to + * be scaled in the range 0..255*65535, so include that scaling here. + */ +# define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha) + +static png_byte +png_unpremultiply(png_uint_32 component, png_uint_32 alpha, + png_uint_32 reciprocal/*from the above macro*/) +{ + /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0 + * is represented as some other value there is more likely to be a + * discontinuity which will probably damage compression when moving from a + * fully transparent area to a nearly transparent one. (The assumption here + * is that opaque areas tend not to be 0 intensity.) + * + * There is a rounding problem here; if alpha is less than 128 it will end up + * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the + * output change for this too. + */ + if (component >= alpha || alpha < 128) + return 255; + + /* component<alpha, so component/alpha is less than one and + * component*reciprocal is less than 2^31. + */ + else if (component > 0) + { + /* The test is that alpha/257 (rounded) is less than 255, the first value + * that becomes 255 is 65407. + * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore, + * be exact!) [Could also test reciprocal != 0] + */ + if (alpha < 65407) + { + component *= reciprocal; + component += 64; /* round to nearest */ + component >>= 7; + } + + else + component *= 255; + + /* Convert the component to sRGB. */ + return (png_byte)PNG_sRGB_FROM_LINEAR(component); + } + + else + return 0; +} + +static int +png_write_image_8bit(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + + png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, + display->first_row); + png_bytep output_row = png_voidcast(png_bytep, display->local_row); + png_uint_32 y = image->height; + const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; + + if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + png_bytep row_end; + int aindex; + +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + aindex = -1; + ++input_row; /* To point to the first component */ + ++output_row; + } + + else +# endif + aindex = channels; + + /* Use row_end in place of a loop counter: */ + row_end = output_row + image->width * (channels+1); + + while (y-- > 0) + { + png_const_uint_16p in_ptr = input_row; + png_bytep out_ptr = output_row; + + while (out_ptr < row_end) + { + png_uint_16 alpha = in_ptr[aindex]; + png_byte alphabyte = (png_byte)PNG_DIV257(alpha); + png_uint_32 reciprocal = 0; + int c; + + /* Scale and write the alpha channel. */ + out_ptr[aindex] = alphabyte; + + if (alphabyte > 0 && alphabyte < 255) + reciprocal = UNP_RECIPROCAL(alpha); + + c = channels; + do /* always at least one channel */ + *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal); + while (--c > 0); + + /* Skip to next component (skip the intervening alpha channel) */ + ++in_ptr; + ++out_ptr; + } /* while out_ptr < row_end */ + + png_write_row(png_ptr, png_voidcast(png_const_bytep, + display->local_row)); + input_row += display->row_bytes/(sizeof (png_uint_16)); + } /* while y */ + } + + else + { + /* No alpha channel, so the row_end really is the end of the row and it + * is sufficient to loop over the components one by one. + */ + png_bytep row_end = output_row + image->width * channels; + + while (y-- > 0) + { + png_const_uint_16p in_ptr = input_row; + png_bytep out_ptr = output_row; + + while (out_ptr < row_end) + { + png_uint_32 component = *in_ptr++; + + component *= 255; + *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component); + } + + png_write_row(png_ptr, output_row); + input_row += display->row_bytes/(sizeof (png_uint_16)); + } + } + + return 1; +} + +static void +png_image_set_PLTE(png_image_write_control *display) +{ + const png_imagep image = display->image; + const void *cmap = display->colormap; + const int entries = image->colormap_entries > 256 ? 256 : + (int)image->colormap_entries; + + /* NOTE: the caller must check for cmap != NULL and entries != 0 */ + const png_uint_32 format = image->format; + const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format); + +# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\ + defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED) + const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 && + (format & PNG_FORMAT_FLAG_ALPHA) != 0; +# else +# define afirst 0 +# endif + +# ifdef PNG_FORMAT_BGR_SUPPORTED + const int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; +# else +# define bgr 0 +# endif + + int i, num_trans; + png_color palette[256]; + png_byte tRNS[256]; + + memset(tRNS, 255, (sizeof tRNS)); + memset(palette, 0, (sizeof palette)); + + for (i=num_trans=0; i<entries; ++i) + { + /* This gets automatically converted to sRGB with reversal of the + * pre-multiplication if the color-map has an alpha channel. + */ + if ((format & PNG_FORMAT_FLAG_LINEAR) != 0) + { + png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); + + entry += i * channels; + + if ((channels & 1) != 0) /* no alpha */ + { + if (channels >= 3) /* RGB */ + { + palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[(2 ^ bgr)]); + palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[1]); + palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[bgr]); + } + + else /* Gray */ + palette[i].blue = palette[i].red = palette[i].green = + (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry); + } + + else /* alpha */ + { + png_uint_16 alpha = entry[afirst ? 0 : channels-1]; + png_byte alphabyte = (png_byte)PNG_DIV257(alpha); + png_uint_32 reciprocal = 0; + + /* Calculate a reciprocal, as in the png_write_image_8bit code above + * this is designed to produce a value scaled to 255*65535 when + * divided by 128 (i.e. asr 7). + */ + if (alphabyte > 0 && alphabyte < 255) + reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha; + + tRNS[i] = alphabyte; + if (alphabyte < 255) + num_trans = i+1; + + if (channels >= 3) /* RGB */ + { + palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)], + alpha, reciprocal); + palette[i].green = png_unpremultiply(entry[afirst + 1], alpha, + reciprocal); + palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha, + reciprocal); + } + + else /* gray */ + palette[i].blue = palette[i].red = palette[i].green = + png_unpremultiply(entry[afirst], alpha, reciprocal); + } + } + + else /* Color-map has sRGB values */ + { + png_const_bytep entry = png_voidcast(png_const_bytep, cmap); + + entry += i * channels; + + switch (channels) + { + case 4: + tRNS[i] = entry[afirst ? 0 : 3]; + if (tRNS[i] < 255) + num_trans = i+1; + /* FALL THROUGH */ + case 3: + palette[i].blue = entry[afirst + (2 ^ bgr)]; + palette[i].green = entry[afirst + 1]; + palette[i].red = entry[afirst + bgr]; + break; + + case 2: + tRNS[i] = entry[1 ^ afirst]; + if (tRNS[i] < 255) + num_trans = i+1; + /* FALL THROUGH */ + case 1: + palette[i].blue = palette[i].red = palette[i].green = + entry[afirst]; + break; + + default: + break; + } + } + } + +# ifdef afirst +# undef afirst +# endif +# ifdef bgr +# undef bgr +# endif + + png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette, + entries); + + if (num_trans > 0) + png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS, + num_trans, NULL); + + image->colormap_entries = entries; +} + +static int +png_image_write_main(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + png_uint_32 format = image->format; + + /* The following four ints are actually booleans */ + int colormap = (format & PNG_FORMAT_FLAG_COLORMAP); + int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */ + int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA); + int write_16bit = linear && !colormap && (display->convert_to_8bit == 0); + +# ifdef PNG_BENIGN_ERRORS_SUPPORTED + /* Make sure we error out on any bad situation */ + png_set_benign_errors(png_ptr, 0/*error*/); +# endif + + /* Default the 'row_stride' parameter if required, also check the row stride + * and total image size to ensure that they are within the system limits. + */ + { + const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); + + if (image->width <= 0x7FFFFFFFU/channels) /* no overflow */ + { + png_uint_32 check; + const png_uint_32 png_row_stride = image->width * channels; + + if (display->row_stride == 0) + display->row_stride = (png_int_32)/*SAFE*/png_row_stride; + + if (display->row_stride < 0) + check = -display->row_stride; + + else + check = display->row_stride; + + if (check >= png_row_stride) + { + /* Now check for overflow of the image buffer calculation; this + * limits the whole image size to 32 bits for API compatibility with + * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. + */ + if (image->height > 0xFFFFFFFF/png_row_stride) + png_error(image->opaque->png_ptr, "memory image too large"); + } + + else + png_error(image->opaque->png_ptr, "supplied row stride too small"); + } + + else + png_error(image->opaque->png_ptr, "image row stride too large"); + } + + /* Set the required transforms then write the rows in the correct order. */ + if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0) + { + if (display->colormap != NULL && image->colormap_entries > 0) + { + png_uint_32 entries = image->colormap_entries; + + png_set_IHDR(png_ptr, info_ptr, image->width, image->height, + entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)), + PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + png_image_set_PLTE(display); + } + + else + png_error(image->opaque->png_ptr, + "no color-map for color-mapped image"); + } + + else + png_set_IHDR(png_ptr, info_ptr, image->width, image->height, + write_16bit ? 16 : 8, + ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) + + ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0), + PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + /* Counter-intuitively the data transformations must be called *after* + * png_write_info, not before as in the read code, but the 'set' functions + * must still be called before. Just set the color space information, never + * write an interlaced image. + */ + + if (write_16bit != 0) + { + /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */ + png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR); + + if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) + png_set_cHRM_fixed(png_ptr, info_ptr, + /* color x y */ + /* white */ 31270, 32900, + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000 + ); + } + + else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) + png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL); + + /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit + * space must still be gamma encoded. + */ + else + png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE); + + /* Write the file header. */ + png_write_info(png_ptr, info_ptr); + + /* Now set up the data transformations (*after* the header is written), + * remove the handled transformations from the 'format' flags for checking. + * + * First check for a little endian system if writing 16-bit files. + */ + if (write_16bit != 0) + { + PNG_CONST png_uint_16 le = 0x0001; + + if ((*(png_const_bytep) & le) != 0) + png_set_swap(png_ptr); + } + +# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED + if ((format & PNG_FORMAT_FLAG_BGR) != 0) + { + if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0) + png_set_bgr(png_ptr); + format &= ~PNG_FORMAT_FLAG_BGR; + } +# endif + +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0) + png_set_swap_alpha(png_ptr); + format &= ~PNG_FORMAT_FLAG_AFIRST; + } +# endif + + /* If there are 16 or fewer color-map entries we wrote a lower bit depth + * above, but the application data is still byte packed. + */ + if (colormap != 0 && image->colormap_entries <= 16) + png_set_packing(png_ptr); + + /* That should have handled all (both) the transforms. */ + if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR | + PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0) + png_error(png_ptr, "png_write_image: unsupported transformation"); + + { + png_const_bytep row = png_voidcast(png_const_bytep, display->buffer); + ptrdiff_t row_bytes = display->row_stride; + + if (linear != 0) + row_bytes *= (sizeof (png_uint_16)); + + if (row_bytes < 0) + row += (image->height-1) * (-row_bytes); + + display->first_row = row; + display->row_bytes = row_bytes; + } + + /* Apply 'fast' options if the flag is set. */ + if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0) + { + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS); + /* NOTE: determined by experiment using pngstest, this reflects some + * balance between the time to write the image once and the time to read + * it about 50 times. The speed-up in pngstest was about 10-20% of the + * total (user) time on a heavily loaded system. + */ +# ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED + png_set_compression_level(png_ptr, 3); +# endif + } + + /* Check for the cases that currently require a pre-transform on the row + * before it is written. This only applies when the input is 16-bit and + * either there is an alpha channel or it is converted to 8-bit. + */ + if ((linear != 0 && alpha != 0 ) || + (colormap == 0 && display->convert_to_8bit != 0)) + { + png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr, + png_get_rowbytes(png_ptr, info_ptr))); + int result; + + display->local_row = row; + if (write_16bit != 0) + result = png_safe_execute(image, png_write_image_16bit, display); + else + result = png_safe_execute(image, png_write_image_8bit, display); + display->local_row = NULL; + + png_free(png_ptr, row); + + /* Skip the 'write_end' on error: */ + if (result == 0) + return 0; + } + + /* Otherwise this is the case where the input is in a format currently + * supported by the rest of the libpng write code; call it directly. + */ + else + { + png_const_bytep row = png_voidcast(png_const_bytep, display->first_row); + ptrdiff_t row_bytes = display->row_bytes; + png_uint_32 y = image->height; + + while (y-- > 0) + { + png_write_row(png_ptr, row); + row += row_bytes; + } + } + + png_write_end(png_ptr, info_ptr); + return 1; +} + + +static void (PNGCBAPI +image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, + png_size_t size) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/); + const png_alloc_size_t ob = display->output_bytes; + + /* Check for overflow; this should never happen: */ + if (size <= ((png_alloc_size_t)-1) - ob) + { + /* I don't think libpng ever does this, but just in case: */ + if (size > 0) + { + if (display->memory_bytes >= ob+size) /* writing */ + memcpy(display->memory+ob, data, size); + + /* Always update the size: */ + display->output_bytes = ob+size; + } + } + + else + png_error(png_ptr, "png_image_write_to_memory: PNG too big"); +} + +static void (PNGCBAPI +image_memory_flush)(png_structp png_ptr) +{ + PNG_UNUSED(png_ptr) +} + +static int +png_image_write_memory(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + + /* The rest of the memory-specific init and write_main in an error protected + * environment. This case needs to use callbacks for the write operations + * since libpng has no built in support for writing to memory. + */ + png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/, + image_memory_write, image_memory_flush); + + return png_image_write_main(display); +} + +int PNGAPI +png_image_write_to_memory(png_imagep image, void *memory, + png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit, + const void *buffer, png_int_32 row_stride, const void *colormap) +{ + /* Write the image to the given buffer, or count the bytes if it is NULL */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (memory_bytes != NULL && buffer != NULL) + { + /* This is to give the caller an easier error detection in the NULL + * case and guard against uninitialized variable problems: + */ + if (memory == NULL) + *memory_bytes = 0; + + if (png_image_write_init(image) != 0) + { + png_image_write_control display; + int result; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.convert_to_8bit = convert_to_8bit; + display.memory = png_voidcast(png_bytep, memory); + display.memory_bytes = *memory_bytes; + display.output_bytes = 0; + + result = png_safe_execute(image, png_image_write_memory, &display); + png_image_free(image); + + /* write_memory returns true even if we ran out of buffer. */ + if (result) + { + /* On out-of-buffer this function returns '0' but still updates + * memory_bytes: + */ + if (memory != NULL && display.output_bytes > *memory_bytes) + result = 0; + + *memory_bytes = display.output_bytes; + } + + return result; + } + + else + return 0; + } + + else + return png_image_error(image, + "png_image_write_to_memory: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} + +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +int PNGAPI +png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, + const void *buffer, png_int_32 row_stride, const void *colormap) +{ + /* Write the image to the given (FILE*). */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file != NULL && buffer != NULL) + { + if (png_image_write_init(image) != 0) + { + png_image_write_control display; + int result; + + /* This is slightly evil, but png_init_io doesn't do anything other + * than this and we haven't changed the standard IO functions so + * this saves a 'safe' function. + */ + image->opaque->png_ptr->io_ptr = file; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.convert_to_8bit = convert_to_8bit; + + result = png_safe_execute(image, png_image_write_main, &display); + png_image_free(image); + return result; + } + + else + return 0; + } + + else + return png_image_error(image, + "png_image_write_to_stdio: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} + +int PNGAPI +png_image_write_to_file(png_imagep image, const char *file_name, + int convert_to_8bit, const void *buffer, png_int_32 row_stride, + const void *colormap) +{ + /* Write the image to the named file. */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file_name != NULL && buffer != NULL) + { + FILE *fp = fopen(file_name, "wb"); + + if (fp != NULL) + { + if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer, + row_stride, colormap) != 0) + { + int error; /* from fflush/fclose */ + + /* Make sure the file is flushed correctly. */ + if (fflush(fp) == 0 && ferror(fp) == 0) + { + if (fclose(fp) == 0) + return 1; + + error = errno; /* from fclose */ + } + + else + { + error = errno; /* from fflush or ferror */ + (void)fclose(fp); + } + + (void)remove(file_name); + /* The image has already been cleaned up; this is just used to + * set the error (because the original write succeeded). + */ + return png_image_error(image, strerror(error)); + } + + else + { + /* Clean up: just the opened file. */ + (void)fclose(fp); + (void)remove(file_name); + return 0; + } + } + + else + return png_image_error(image, strerror(errno)); + } + + else + return png_image_error(image, + "png_image_write_to_file: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_file: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} +#endif /* SIMPLIFIED_WRITE_STDIO */ +#endif /* SIMPLIFIED_WRITE */ +#endif /* WRITE */ diff --git a/thirdparty/libpng/pngwtran.c b/thirdparty/libpng/pngwtran.c new file mode 100644 index 0000000000..038a2ef5dc --- /dev/null +++ b/thirdparty/libpng/pngwtran.c @@ -0,0 +1,576 @@ + +/* pngwtran.c - transforms the data in a row for PNG writers + * + * Last changed in libpng 1.6.18 [July 23, 2015] + * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED + +#ifdef PNG_WRITE_PACK_SUPPORTED +/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The + * row_info bit depth should be 8 (one pixel per byte). The channels + * should be 1 (this only happens on grayscale and paletted images). + */ +static void +png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) +{ + png_debug(1, "in png_do_pack"); + + if (row_info->bit_depth == 8 && + row_info->channels == 1) + { + switch ((int)bit_depth) + { + case 1: + { + png_bytep sp, dp; + int mask, v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + mask = 0x80; + v = 0; + + for (i = 0; i < row_width; i++) + { + if (*sp != 0) + v |= mask; + + sp++; + + if (mask > 1) + mask >>= 1; + + else + { + mask = 0x80; + *dp = (png_byte)v; + dp++; + v = 0; + } + } + + if (mask != 0x80) + *dp = (png_byte)v; + + break; + } + + case 2: + { + png_bytep sp, dp; + unsigned int shift; + int v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + shift = 6; + v = 0; + + for (i = 0; i < row_width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0x03); + v |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp = (png_byte)v; + dp++; + v = 0; + } + + else + shift -= 2; + + sp++; + } + + if (shift != 6) + *dp = (png_byte)v; + + break; + } + + case 4: + { + png_bytep sp, dp; + unsigned int shift; + int v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + shift = 4; + v = 0; + + for (i = 0; i < row_width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0x0f); + v |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp = (png_byte)v; + dp++; + v = 0; + } + + else + shift -= 4; + + sp++; + } + + if (shift != 4) + *dp = (png_byte)v; + + break; + } + + default: + break; + } + + row_info->bit_depth = (png_byte)bit_depth; + row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); + } +} +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED +/* Shift pixel values to take advantage of whole range. Pass the + * true number of bits in bit_depth. The row should be packed + * according to row_info->bit_depth. Thus, if you had a row of + * bit depth 4, but the pixels only had values from 0 to 7, you + * would pass 3 as bit_depth, and this routine would translate the + * data to 0 to 15. + */ +static void +png_do_shift(png_row_infop row_info, png_bytep row, + png_const_color_8p bit_depth) +{ + png_debug(1, "in png_do_shift"); + + if (row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift_start[4], shift_dec[4]; + int channels = 0; + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + shift_start[channels] = row_info->bit_depth - bit_depth->red; + shift_dec[channels] = bit_depth->red; + channels++; + + shift_start[channels] = row_info->bit_depth - bit_depth->green; + shift_dec[channels] = bit_depth->green; + channels++; + + shift_start[channels] = row_info->bit_depth - bit_depth->blue; + shift_dec[channels] = bit_depth->blue; + channels++; + } + + else + { + shift_start[channels] = row_info->bit_depth - bit_depth->gray; + shift_dec[channels] = bit_depth->gray; + channels++; + } + + if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + shift_start[channels] = row_info->bit_depth - bit_depth->alpha; + shift_dec[channels] = bit_depth->alpha; + channels++; + } + + /* With low row depths, could only be grayscale, so one channel */ + if (row_info->bit_depth < 8) + { + png_bytep bp = row; + png_size_t i; + unsigned int mask; + png_size_t row_bytes = row_info->rowbytes; + + if (bit_depth->gray == 1 && row_info->bit_depth == 2) + mask = 0x55; + + else if (row_info->bit_depth == 4 && bit_depth->gray == 3) + mask = 0x11; + + else + mask = 0xff; + + for (i = 0; i < row_bytes; i++, bp++) + { + int j; + unsigned int v, out; + + v = *bp; + out = 0; + + for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0]) + { + if (j > 0) + out |= v << j; + + else + out |= (v >> (-j)) & mask; + } + + *bp = (png_byte)(out & 0xff); + } + } + + else if (row_info->bit_depth == 8) + { + png_bytep bp = row; + png_uint_32 i; + png_uint_32 istop = channels * row_info->width; + + for (i = 0; i < istop; i++, bp++) + { + + const unsigned int c = i%channels; + int j; + unsigned int v, out; + + v = *bp; + out = 0; + + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + out |= v << j; + + else + out |= v >> (-j); + } + + *bp = (png_byte)(out & 0xff); + } + } + + else + { + png_bytep bp; + png_uint_32 i; + png_uint_32 istop = channels * row_info->width; + + for (bp = row, i = 0; i < istop; i++) + { + const unsigned int c = i%channels; + int j; + unsigned int value, v; + + v = png_get_uint_16(bp); + value = 0; + + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + value |= v << j; + + else + value |= v >> (-j); + } + *bp++ = (png_byte)((value >> 8) & 0xff); + *bp++ = (png_byte)(value & 0xff); + } + } + } +} +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED +static void +png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_swap_alpha"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This converts from ARGB to RGBA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This converts from AARRGGBB to RRGGBBAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save[2]; + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } +#endif /* WRITE_16BIT */ + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This converts from AG to GA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This converts from AAGG to GGAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save[2]; + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } +#endif /* WRITE_16BIT */ + } + } +} +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED +static void +png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_invert_alpha"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in RGBA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=3; dp = sp; + *dp = (png_byte)(255 - *(sp++)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in RRGGBBAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=6; dp = sp; + *(dp++) = (png_byte)(255 - *(sp++)); + *dp = (png_byte)(255 - *(sp++)); + } + } +#endif /* WRITE_16BIT */ + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in GA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + *(dp++) = *(sp++); + *(dp++) = (png_byte)(255 - *(sp++)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in GGAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=2; dp = sp; + *(dp++) = (png_byte)(255 - *(sp++)); + *dp = (png_byte)(255 - *(sp++)); + } + } +#endif /* WRITE_16BIT */ + } + } +} +#endif + +/* Transform the data according to the user's wishes. The order of + * transformations is significant. + */ +void /* PRIVATE */ +png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info) +{ + png_debug(1, "in png_do_write_transformations"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) + if (png_ptr->write_user_transform_fn != NULL) + (*(png_ptr->write_user_transform_fn)) /* User write transform + function */ + (png_ptr, /* png_ptr */ + row_info, /* row_info: */ + /* png_uint_32 width; width of row */ + /* png_size_t rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#endif + +#ifdef PNG_WRITE_FILLER_SUPPORTED + if ((png_ptr->transformations & PNG_FILLER) != 0) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, + !(png_ptr->flags & PNG_FLAG_FILLER_AFTER)); +#endif + +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) + png_do_packswap(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) != 0) + png_do_pack(row_info, png_ptr->row_buf + 1, + (png_uint_32)png_ptr->bit_depth); +#endif + +#ifdef PNG_WRITE_SWAP_SUPPORTED +# ifdef PNG_16BIT_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) + png_do_swap(row_info, png_ptr->row_buf + 1); +# endif +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED + if ((png_ptr->transformations & PNG_SHIFT) != 0) + png_do_shift(row_info, png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) + png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) + png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_BGR_SUPPORTED + if ((png_ptr->transformations & PNG_BGR) != 0) + png_do_bgr(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_INVERT_SUPPORTED + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) + png_do_invert(row_info, png_ptr->row_buf + 1); +#endif +} +#endif /* WRITE_TRANSFORMS */ +#endif /* WRITE */ diff --git a/thirdparty/libpng/pngwutil.c b/thirdparty/libpng/pngwutil.c new file mode 100644 index 0000000000..b47f119d22 --- /dev/null +++ b/thirdparty/libpng/pngwutil.c @@ -0,0 +1,2625 @@ + +/* pngwutil.c - utilities to write a PNG file + * + * Last changed in libpng 1.6.22 [May 26, 2016] + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +/* Place a 32-bit number into a buffer in PNG byte order. We work + * with unsigned numbers for convenience, although one supported + * ancillary chunk uses signed (two's complement) numbers. + */ +void PNGAPI +png_save_uint_32(png_bytep buf, png_uint_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xffU); + buf[1] = (png_byte)((i >> 16) & 0xffU); + buf[2] = (png_byte)((i >> 8) & 0xffU); + buf[3] = (png_byte)( i & 0xffU); +} + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +void PNGAPI +png_save_uint_16(png_bytep buf, unsigned int i) +{ + buf[0] = (png_byte)((i >> 8) & 0xffU); + buf[1] = (png_byte)( i & 0xffU); +} +#endif + +/* Simple function to write the signature. If we have already written + * the magic bytes of the signature, or more likely, the PNG stream is + * being embedded into another stream and doesn't need its own signature, + * we should call png_set_sig_bytes() to tell libpng how many of the + * bytes have already been written. + */ +void PNGAPI +png_write_sig(png_structrp png_ptr) +{ + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the signature is being written */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; +#endif + + /* Write the rest of the 8 byte signature */ + png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], + (png_size_t)(8 - png_ptr->sig_bytes)); + + if (png_ptr->sig_bytes < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Write the start of a PNG chunk. The type is the chunk type. + * The total_length is the sum of the lengths of all the data you will be + * passing in png_write_chunk_data(). + */ +static void +png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name, + png_uint_32 length) +{ + png_byte buf[8]; + +#if defined(PNG_DEBUG) && (PNG_DEBUG > 0) + PNG_CSTRING_FROM_CHUNK(buf, chunk_name); + png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length); +#endif + + if (png_ptr == NULL) + return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk header is being written. + * PNG_IO_CHUNK_HDR requires a single I/O call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; +#endif + + /* Write the length and the chunk name */ + png_save_uint_32(buf, length); + png_save_uint_32(buf + 4, chunk_name); + png_write_data(png_ptr, buf, 8); + + /* Put the chunk name into png_ptr->chunk_name */ + png_ptr->chunk_name = chunk_name; + + /* Reset the crc and run it over the chunk name */ + png_reset_crc(png_ptr); + + png_calculate_crc(png_ptr, buf + 4, 4); + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that chunk data will (possibly) be written. + * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; +#endif +} + +void PNGAPI +png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string, + png_uint_32 length) +{ + png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length); +} + +/* Write the data of a PNG chunk started with png_write_chunk_header(). + * Note that multiple calls to this function are allowed, and that the + * sum of the lengths from these calls *must* add up to the total_length + * given to png_write_chunk_header(). + */ +void PNGAPI +png_write_chunk_data(png_structrp png_ptr, png_const_bytep data, + png_size_t length) +{ + /* Write the data, and run the CRC over it */ + if (png_ptr == NULL) + return; + + if (data != NULL && length > 0) + { + png_write_data(png_ptr, data, length); + + /* Update the CRC after writing the data, + * in case the user I/O routine alters it. + */ + png_calculate_crc(png_ptr, data, length); + } +} + +/* Finish a chunk started with png_write_chunk_header(). */ +void PNGAPI +png_write_chunk_end(png_structrp png_ptr) +{ + png_byte buf[4]; + + if (png_ptr == NULL) return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk CRC is being written. + * PNG_IO_CHUNK_CRC requires a single I/O function call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; +#endif + + /* Write the crc in a single operation */ + png_save_uint_32(buf, png_ptr->crc); + + png_write_data(png_ptr, buf, (png_size_t)4); +} + +/* Write a PNG chunk all at once. The type is an array of ASCII characters + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. + */ +static void +png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name, + png_const_bytep data, png_size_t length) +{ + if (png_ptr == NULL) + return; + + /* On 64-bit architectures 'length' may not fit in a png_uint_32. */ + if (length > PNG_UINT_31_MAX) + png_error(png_ptr, "length exceeds PNG maximum"); + + png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); + png_write_chunk_data(png_ptr, data, length); + png_write_chunk_end(png_ptr); +} + +/* This is the API that calls the internal function above. */ +void PNGAPI +png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string, + png_const_bytep data, png_size_t length) +{ + png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data, + length); +} + +/* This is used below to find the size of an image to pass to png_deflate_claim, + * so it only needs to be accurate if the size is less than 16384 bytes (the + * point at which a lower LZ window size can be used.) + */ +static png_alloc_size_t +png_image_size(png_structrp png_ptr) +{ + /* Only return sizes up to the maximum of a png_uint_32; do this by limiting + * the width and height used to 15 bits. + */ + png_uint_32 h = png_ptr->height; + + if (png_ptr->rowbytes < 32768 && h < 32768) + { + if (png_ptr->interlaced != 0) + { + /* Interlacing makes the image larger because of the replication of + * both the filter byte and the padding to a byte boundary. + */ + png_uint_32 w = png_ptr->width; + unsigned int pd = png_ptr->pixel_depth; + png_alloc_size_t cb_base; + int pass; + + for (cb_base=0, pass=0; pass<=6; ++pass) + { + png_uint_32 pw = PNG_PASS_COLS(w, pass); + + if (pw > 0) + cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass); + } + + return cb_base; + } + + else + return (png_ptr->rowbytes+1) * h; + } + + else + return 0xffffffffU; +} + +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* This is the code to hack the first two bytes of the deflate stream (the + * deflate header) to correct the windowBits value to match the actual data + * size. Note that the second argument is the *uncompressed* size but the + * first argument is the *compressed* data (and it must be deflate + * compressed.) + */ +static void +optimize_cmf(png_bytep data, png_alloc_size_t data_size) +{ + /* Optimize the CMF field in the zlib stream. The resultant zlib stream is + * still compliant to the stream specification. + */ + if (data_size <= 16384) /* else windowBits must be 15 */ + { + unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + unsigned int z_cinfo; + unsigned int half_z_window_size; + + z_cinfo = z_cmf >> 4; + half_z_window_size = 1U << (z_cinfo + 7); + + if (data_size <= half_z_window_size) /* else no change */ + { + unsigned int tmp; + + do + { + half_z_window_size >>= 1; + --z_cinfo; + } + while (z_cinfo > 0 && data_size <= half_z_window_size); + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + data[0] = (png_byte)z_cmf; + tmp = data[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + data[1] = (png_byte)tmp; + } + } + } +} +#endif /* WRITE_OPTIMIZE_CMF */ + +/* Initialize the compressor for the appropriate type of compression. */ +static int +png_deflate_claim(png_structrp png_ptr, png_uint_32 owner, + png_alloc_size_t data_size) +{ + if (png_ptr->zowner != 0) + { +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED) + char msg[64]; + + PNG_STRING_FROM_CHUNK(msg, owner); + msg[4] = ':'; + msg[5] = ' '; + PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner); + /* So the message that results is "<chunk> using zstream"; this is an + * internal error, but is very useful for debugging. i18n requirements + * are minimal. + */ + (void)png_safecat(msg, (sizeof msg), 10, " using zstream"); +#endif +#if PNG_RELEASE_BUILD + png_warning(png_ptr, msg); + + /* Attempt sane error recovery */ + if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */ + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT"); + return Z_STREAM_ERROR; + } + + png_ptr->zowner = 0; +#else + png_error(png_ptr, msg); +#endif + } + + { + int level = png_ptr->zlib_level; + int method = png_ptr->zlib_method; + int windowBits = png_ptr->zlib_window_bits; + int memLevel = png_ptr->zlib_mem_level; + int strategy; /* set below */ + int ret; /* zlib return code */ + + if (owner == png_IDAT) + { + if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0) + strategy = png_ptr->zlib_strategy; + + else if (png_ptr->do_filter != PNG_FILTER_NONE) + strategy = PNG_Z_DEFAULT_STRATEGY; + + else + strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY; + } + + else + { +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + level = png_ptr->zlib_text_level; + method = png_ptr->zlib_text_method; + windowBits = png_ptr->zlib_text_window_bits; + memLevel = png_ptr->zlib_text_mem_level; + strategy = png_ptr->zlib_text_strategy; +#else + /* If customization is not supported the values all come from the + * IDAT values except for the strategy, which is fixed to the + * default. (This is the pre-1.6.0 behavior too, although it was + * implemented in a very different way.) + */ + strategy = Z_DEFAULT_STRATEGY; +#endif + } + + /* Adjust 'windowBits' down if larger than 'data_size'; to stop this + * happening just pass 32768 as the data_size parameter. Notice that zlib + * requires an extra 262 bytes in the window in addition to the data to be + * able to see the whole of the data, so if data_size+262 takes us to the + * next windowBits size we need to fix up the value later. (Because even + * though deflate needs the extra window, inflate does not!) + */ + if (data_size <= 16384) + { + /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to + * work round a Microsoft Visual C misbehavior which, contrary to C-90, + * widens the result of the following shift to 64-bits if (and, + * apparently, only if) it is used in a test. + */ + unsigned int half_window_size = 1U << (windowBits-1); + + while (data_size + 262 <= half_window_size) + { + half_window_size >>= 1; + --windowBits; + } + } + + /* Check against the previous initialized values, if any. */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 && + (png_ptr->zlib_set_level != level || + png_ptr->zlib_set_method != method || + png_ptr->zlib_set_window_bits != windowBits || + png_ptr->zlib_set_mem_level != memLevel || + png_ptr->zlib_set_strategy != strategy)) + { + if (deflateEnd(&png_ptr->zstream) != Z_OK) + png_warning(png_ptr, "deflateEnd failed (ignored)"); + + png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED; + } + + /* For safety clear out the input and output pointers (currently zlib + * doesn't use them on Init, but it might in the future). + */ + png_ptr->zstream.next_in = NULL; + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->zstream.avail_out = 0; + + /* Now initialize if required, setting the new parameters, otherwise just + * to a simple reset to the previous parameters. + */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) + ret = deflateReset(&png_ptr->zstream); + + else + { + ret = deflateInit2(&png_ptr->zstream, level, method, windowBits, + memLevel, strategy); + + if (ret == Z_OK) + png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; + } + + /* The return code is from either deflateReset or deflateInit2; they have + * pretty much the same set of error codes. + */ + if (ret == Z_OK) + png_ptr->zowner = owner; + + else + png_zstream_error(png_ptr, ret); + + return ret; + } +} + +/* Clean up (or trim) a linked list of compression buffers. */ +void /* PRIVATE */ +png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp) +{ + png_compression_bufferp list = *listp; + + if (list != NULL) + { + *listp = NULL; + + do + { + png_compression_bufferp next = list->next; + + png_free(png_ptr, list); + list = next; + } + while (list != NULL); + } +} + +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED +/* This pair of functions encapsulates the operation of (a) compressing a + * text string, and (b) issuing it later as a series of chunk data writes. + * The compression_state structure is shared context for these functions + * set up by the caller to allow access to the relevant local variables. + * + * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size + * temporary buffers. From 1.6.0 it is retained in png_struct so that it will + * be correctly freed in the event of a write error (previous implementations + * just leaked memory.) + */ +typedef struct +{ + png_const_bytep input; /* The uncompressed input data */ + png_alloc_size_t input_len; /* Its length */ + png_uint_32 output_len; /* Final compressed length */ + png_byte output[1024]; /* First block of output */ +} compression_state; + +static void +png_text_compress_init(compression_state *comp, png_const_bytep input, + png_alloc_size_t input_len) +{ + comp->input = input; + comp->input_len = input_len; + comp->output_len = 0; +} + +/* Compress the data in the compression state input */ +static int +png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name, + compression_state *comp, png_uint_32 prefix_len) +{ + int ret; + + /* To find the length of the output it is necessary to first compress the + * input. The result is buffered rather than using the two-pass algorithm + * that is used on the inflate side; deflate is assumed to be slower and a + * PNG writer is assumed to have more memory available than a PNG reader. + * + * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an + * upper limit on the output size, but it is always bigger than the input + * size so it is likely to be more efficient to use this linked-list + * approach. + */ + ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len); + + if (ret != Z_OK) + return ret; + + /* Set up the compression buffers, we need a loop here to avoid overflowing a + * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited + * by the output buffer size, so there is no need to check that. Since this + * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits + * in size. + */ + { + png_compression_bufferp *end = &png_ptr->zbuffer_list; + png_alloc_size_t input_len = comp->input_len; /* may be zero! */ + png_uint_32 output_len; + + /* zlib updates these for us: */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input); + png_ptr->zstream.avail_in = 0; /* Set below */ + png_ptr->zstream.next_out = comp->output; + png_ptr->zstream.avail_out = (sizeof comp->output); + + output_len = png_ptr->zstream.avail_out; + + do + { + uInt avail_in = ZLIB_IO_MAX; + + if (avail_in > input_len) + avail_in = (uInt)input_len; + + input_len -= avail_in; + + png_ptr->zstream.avail_in = avail_in; + + if (png_ptr->zstream.avail_out == 0) + { + png_compression_buffer *next; + + /* Chunk data is limited to 2^31 bytes in length, so the prefix + * length must be counted here. + */ + if (output_len + prefix_len > PNG_UINT_31_MAX) + { + ret = Z_MEM_ERROR; + break; + } + + /* Need a new (malloc'ed) buffer, but there may be one present + * already. + */ + next = *end; + if (next == NULL) + { + next = png_voidcast(png_compression_bufferp, png_malloc_base + (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); + + if (next == NULL) + { + ret = Z_MEM_ERROR; + break; + } + + /* Link in this buffer (so that it will be freed later) */ + next->next = NULL; + *end = next; + } + + png_ptr->zstream.next_out = next->output; + png_ptr->zstream.avail_out = png_ptr->zbuffer_size; + output_len += png_ptr->zstream.avail_out; + + /* Move 'end' to the next buffer pointer. */ + end = &next->next; + } + + /* Compress the data */ + ret = deflate(&png_ptr->zstream, + input_len > 0 ? Z_NO_FLUSH : Z_FINISH); + + /* Claw back input data that was not consumed (because avail_in is + * reset above every time round the loop). + */ + input_len += png_ptr->zstream.avail_in; + png_ptr->zstream.avail_in = 0; /* safety */ + } + while (ret == Z_OK); + + /* There may be some space left in the last output buffer. This needs to + * be subtracted from output_len. + */ + output_len -= png_ptr->zstream.avail_out; + png_ptr->zstream.avail_out = 0; /* safety */ + comp->output_len = output_len; + + /* Now double check the output length, put in a custom message if it is + * too long. Otherwise ensure the z_stream::msg pointer is set to + * something. + */ + if (output_len + prefix_len >= PNG_UINT_31_MAX) + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long"); + ret = Z_MEM_ERROR; + } + + else + png_zstream_error(png_ptr, ret); + + /* Reset zlib for another zTXt/iTXt or image data */ + png_ptr->zowner = 0; + + /* The only success case is Z_STREAM_END, input_len must be 0; if not this + * is an internal error. + */ + if (ret == Z_STREAM_END && input_len == 0) + { +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* Fix up the deflate header, if required */ + optimize_cmf(comp->output, comp->input_len); +#endif + /* But Z_OK is returned, not Z_STREAM_END; this allows the claim + * function above to return Z_STREAM_END on an error (though it never + * does in the current versions of zlib.) + */ + return Z_OK; + } + + else + return ret; + } +} + +/* Ship the compressed text out via chunk writes */ +static void +png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp) +{ + png_uint_32 output_len = comp->output_len; + png_const_bytep output = comp->output; + png_uint_32 avail = (sizeof comp->output); + png_compression_buffer *next = png_ptr->zbuffer_list; + + for (;;) + { + if (avail > output_len) + avail = output_len; + + png_write_chunk_data(png_ptr, output, avail); + + output_len -= avail; + + if (output_len == 0 || next == NULL) + break; + + avail = png_ptr->zbuffer_size; + output = next->output; + next = next->next; + } + + /* This is an internal error; 'next' must have been NULL! */ + if (output_len > 0) + png_error(png_ptr, "error writing ancillary chunked compressed data"); +} +#endif /* WRITE_COMPRESSED_TEXT */ + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. Note that the rest of this code depends upon this + * information being correct. + */ +void /* PRIVATE */ +png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height, + int bit_depth, int color_type, int compression_type, int filter_type, + int interlace_type) +{ + png_byte buf[13]; /* Buffer to store the IHDR info */ + + png_debug(1, "in png_write_IHDR"); + + /* Check that we have valid input data from the application info */ + switch (color_type) + { + case PNG_COLOR_TYPE_GRAY: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: +#ifdef PNG_WRITE_16BIT_SUPPORTED + case 16: +#endif + png_ptr->channels = 1; break; + + default: + png_error(png_ptr, + "Invalid bit depth for grayscale image"); + } + break; + + case PNG_COLOR_TYPE_RGB: +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif + png_error(png_ptr, "Invalid bit depth for RGB image"); + + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_PALETTE: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: + png_ptr->channels = 1; + break; + + default: + png_error(png_ptr, "Invalid bit depth for paletted image"); + } + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + if (bit_depth != 8 && bit_depth != 16) + png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); + + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif + png_error(png_ptr, "Invalid bit depth for RGBA image"); + + png_ptr->channels = 4; + break; + + default: + png_error(png_ptr, "Invalid image color type specified"); + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Invalid compression type specified"); + compression_type = PNG_COMPRESSION_TYPE_BASE; + } + + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && +#endif + filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Invalid filter type specified"); + filter_type = PNG_FILTER_TYPE_BASE; + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + if (interlace_type != PNG_INTERLACE_NONE && + interlace_type != PNG_INTERLACE_ADAM7) + { + png_warning(png_ptr, "Invalid interlace type specified"); + interlace_type = PNG_INTERLACE_ADAM7; + } +#else + interlace_type=PNG_INTERLACE_NONE; +#endif + + /* Save the relevant information */ + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->color_type = (png_byte)color_type; + png_ptr->interlaced = (png_byte)interlace_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + png_ptr->width = width; + png_ptr->height = height; + + png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); + /* Set the usr info, so any transformations can modify it */ + png_ptr->usr_width = png_ptr->width; + png_ptr->usr_bit_depth = png_ptr->bit_depth; + png_ptr->usr_channels = png_ptr->channels; + + /* Pack the header information into the buffer */ + png_save_uint_32(buf, width); + png_save_uint_32(buf + 4, height); + buf[8] = (png_byte)bit_depth; + buf[9] = (png_byte)color_type; + buf[10] = (png_byte)compression_type; + buf[11] = (png_byte)filter_type; + buf[12] = (png_byte)interlace_type; + + /* Write the chunk */ + png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); + + if ((png_ptr->do_filter) == PNG_NO_FILTERS) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + png_ptr->bit_depth < 8) + png_ptr->do_filter = PNG_FILTER_NONE; + + else + png_ptr->do_filter = PNG_ALL_FILTERS; + } + + png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */ +} + +/* Write the palette. We are careful not to trust png_color to be in the + * correct order for PNG, so people can redefine it to any convenient + * structure. + */ +void /* PRIVATE */ +png_write_PLTE(png_structrp png_ptr, png_const_colorp palette, + png_uint_32 num_pal) +{ + png_uint_32 max_palette_length, i; + png_const_colorp pal_ptr; + png_byte buf[3]; + + png_debug(1, "in png_write_PLTE"); + + max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ? + (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH; + + if (( +#ifdef PNG_MNG_FEATURES_SUPPORTED + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 && +#endif + num_pal == 0) || num_pal > max_palette_length) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_error(png_ptr, "Invalid number of colors in palette"); + } + + else + { + png_warning(png_ptr, "Invalid number of colors in palette"); + return; + } + } + + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) + { + png_warning(png_ptr, + "Ignoring request to write a PLTE chunk in grayscale PNG"); + + return; + } + + png_ptr->num_palette = (png_uint_16)num_pal; + png_debug1(3, "num_palette = %d", png_ptr->num_palette); + + png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); +#ifdef PNG_POINTER_INDEXING_SUPPORTED + + for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) + { + buf[0] = pal_ptr->red; + buf[1] = pal_ptr->green; + buf[2] = pal_ptr->blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + +#else + /* This is a little slower but some buggy compilers need to do this + * instead + */ + pal_ptr=palette; + + for (i = 0; i < num_pal; i++) + { + buf[0] = pal_ptr[i].red; + buf[1] = pal_ptr[i].green; + buf[2] = pal_ptr[i].blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + +#endif + png_write_chunk_end(png_ptr); + png_ptr->mode |= PNG_HAVE_PLTE; +} + +/* This is similar to png_text_compress, above, except that it does not require + * all of the data at once and, instead of buffering the compressed result, + * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out + * because it calls the write interface. As a result it does its own error + * reporting and does not return an error code. In the event of error it will + * just call png_error. The input data length may exceed 32-bits. The 'flush' + * parameter is exactly the same as that to deflate, with the following + * meanings: + * + * Z_NO_FLUSH: normal incremental output of compressed data + * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush + * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up + * + * The routine manages the acquire and release of the png_ptr->zstream by + * checking and (at the end) clearing png_ptr->zowner; it does some sanity + * checks on the 'mode' flags while doing this. + */ +void /* PRIVATE */ +png_compress_IDAT(png_structrp png_ptr, png_const_bytep input, + png_alloc_size_t input_len, int flush) +{ + if (png_ptr->zowner != png_IDAT) + { + /* First time. Ensure we have a temporary buffer for compression and + * trim the buffer list if it has more than one entry to free memory. + * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been + * created at this point, but the check here is quick and safe. + */ + if (png_ptr->zbuffer_list == NULL) + { + png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp, + png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); + png_ptr->zbuffer_list->next = NULL; + } + + else + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next); + + /* It is a terminal error if we can't claim the zstream. */ + if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + /* The output state is maintained in png_ptr->zstream, so it must be + * initialized here after the claim. + */ + png_ptr->zstream.next_out = png_ptr->zbuffer_list->output; + png_ptr->zstream.avail_out = png_ptr->zbuffer_size; + } + + /* Now loop reading and writing until all the input is consumed or an error + * terminates the operation. The _out values are maintained across calls to + * this function, but the input must be reset each time. + */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); + png_ptr->zstream.avail_in = 0; /* set below */ + for (;;) + { + int ret; + + /* INPUT: from the row data */ + uInt avail = ZLIB_IO_MAX; + + if (avail > input_len) + avail = (uInt)input_len; /* safe because of the check */ + + png_ptr->zstream.avail_in = avail; + input_len -= avail; + + ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush); + + /* Include as-yet unconsumed input */ + input_len += png_ptr->zstream.avail_in; + png_ptr->zstream.avail_in = 0; + + /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note + * that these two zstream fields are preserved across the calls, therefore + * there is no need to set these up on entry to the loop. + */ + if (png_ptr->zstream.avail_out == 0) + { + png_bytep data = png_ptr->zbuffer_list->output; + uInt size = png_ptr->zbuffer_size; + + /* Write an IDAT containing the data then reset the buffer. The + * first IDAT may need deflate header optimization. + */ +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + optimize_cmf(data, png_image_size(png_ptr)); +#endif + + png_write_complete_chunk(png_ptr, png_IDAT, data, size); + png_ptr->mode |= PNG_HAVE_IDAT; + + png_ptr->zstream.next_out = data; + png_ptr->zstream.avail_out = size; + + /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with + * the same flush parameter until it has finished output, for NO_FLUSH + * it doesn't matter. + */ + if (ret == Z_OK && flush != Z_NO_FLUSH) + continue; + } + + /* The order of these checks doesn't matter much; it just affects which + * possible error might be detected if multiple things go wrong at once. + */ + if (ret == Z_OK) /* most likely return code! */ + { + /* If all the input has been consumed then just return. If Z_FINISH + * was used as the flush parameter something has gone wrong if we get + * here. + */ + if (input_len == 0) + { + if (flush == Z_FINISH) + png_error(png_ptr, "Z_OK on Z_FINISH with output space"); + + return; + } + } + + else if (ret == Z_STREAM_END && flush == Z_FINISH) + { + /* This is the end of the IDAT data; any pending output must be + * flushed. For small PNG files we may still be at the beginning. + */ + png_bytep data = png_ptr->zbuffer_list->output; + uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out; + +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + optimize_cmf(data, png_image_size(png_ptr)); +#endif + + png_write_complete_chunk(png_ptr, png_IDAT, data, size); + png_ptr->zstream.avail_out = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT; + + png_ptr->zowner = 0; /* Release the stream */ + return; + } + + else + { + /* This is an error condition. */ + png_zstream_error(png_ptr, ret); + png_error(png_ptr, png_ptr->zstream.msg); + } + } +} + +/* Write an IEND chunk */ +void /* PRIVATE */ +png_write_IEND(png_structrp png_ptr) +{ + png_debug(1, "in png_write_IEND"); + + png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); + png_ptr->mode |= PNG_HAVE_IEND; +} + +#ifdef PNG_WRITE_gAMA_SUPPORTED +/* Write a gAMA chunk */ +void /* PRIVATE */ +png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma) +{ + png_byte buf[4]; + + png_debug(1, "in png_write_gAMA"); + + /* file_gamma is saved in 1/100,000ths */ + png_save_uint_32(buf, (png_uint_32)file_gamma); + png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); +} +#endif + +#ifdef PNG_WRITE_sRGB_SUPPORTED +/* Write a sRGB chunk */ +void /* PRIVATE */ +png_write_sRGB(png_structrp png_ptr, int srgb_intent) +{ + png_byte buf[1]; + + png_debug(1, "in png_write_sRGB"); + + if (srgb_intent >= PNG_sRGB_INTENT_LAST) + png_warning(png_ptr, + "Invalid sRGB rendering intent specified"); + + buf[0]=(png_byte)srgb_intent; + png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); +} +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +/* Write an iCCP chunk */ +void /* PRIVATE */ +png_write_iCCP(png_structrp png_ptr, png_const_charp name, + png_const_bytep profile) +{ + png_uint_32 name_len; + png_uint_32 profile_len; + png_byte new_name[81]; /* 1 byte for the compression byte */ + compression_state comp; + png_uint_32 temp; + + png_debug(1, "in png_write_iCCP"); + + /* These are all internal problems: the profile should have been checked + * before when it was stored. + */ + if (profile == NULL) + png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */ + + profile_len = png_get_uint_32(profile); + + if (profile_len < 132) + png_error(png_ptr, "ICC profile too short"); + + temp = (png_uint_32) (*(profile+8)); + if (temp > 3 && (profile_len & 0x03)) + png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)"); + + { + png_uint_32 embedded_profile_len = png_get_uint_32(profile); + + if (profile_len != embedded_profile_len) + png_error(png_ptr, "Profile length does not match profile"); + } + + name_len = png_check_keyword(png_ptr, name, new_name); + + if (name_len == 0) + png_error(png_ptr, "iCCP: invalid keyword"); + + new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE; + + /* Make sure we include the NULL after the name and the compression type */ + ++name_len; + + png_text_compress_init(&comp, profile, profile_len); + + /* Allow for keyword terminator and compression byte */ + if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len); + + png_write_chunk_data(png_ptr, new_name, name_len); + + png_write_compressed_data_out(png_ptr, &comp); + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +/* Write a sPLT chunk */ +void /* PRIVATE */ +png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette) +{ + png_uint_32 name_len; + png_byte new_name[80]; + png_byte entrybuf[10]; + png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); + png_size_t palette_size = entry_size * spalette->nentries; + png_sPLT_entryp ep; +#ifndef PNG_POINTER_INDEXING_SUPPORTED + int i; +#endif + + png_debug(1, "in png_write_sPLT"); + + name_len = png_check_keyword(png_ptr, spalette->name, new_name); + + if (name_len == 0) + png_error(png_ptr, "sPLT: invalid keyword"); + + /* Make sure we include the NULL after the name */ + png_write_chunk_header(png_ptr, png_sPLT, + (png_uint_32)(name_len + 2 + palette_size)); + + png_write_chunk_data(png_ptr, (png_bytep)new_name, + (png_size_t)(name_len + 1)); + + png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); + + /* Loop through each palette entry, writing appropriately */ +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep->red; + entrybuf[1] = (png_byte)ep->green; + entrybuf[2] = (png_byte)ep->blue; + entrybuf[3] = (png_byte)ep->alpha; + png_save_uint_16(entrybuf + 4, ep->frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep->red); + png_save_uint_16(entrybuf + 2, ep->green); + png_save_uint_16(entrybuf + 4, ep->blue); + png_save_uint_16(entrybuf + 6, ep->alpha); + png_save_uint_16(entrybuf + 8, ep->frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, entry_size); + } +#else + ep=spalette->entries; + for (i = 0; i>spalette->nentries; i++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep[i].red; + entrybuf[1] = (png_byte)ep[i].green; + entrybuf[2] = (png_byte)ep[i].blue; + entrybuf[3] = (png_byte)ep[i].alpha; + png_save_uint_16(entrybuf + 4, ep[i].frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep[i].red); + png_save_uint_16(entrybuf + 2, ep[i].green); + png_save_uint_16(entrybuf + 4, ep[i].blue); + png_save_uint_16(entrybuf + 6, ep[i].alpha); + png_save_uint_16(entrybuf + 8, ep[i].frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, entry_size); + } +#endif + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +/* Write the sBIT chunk */ +void /* PRIVATE */ +png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type) +{ + png_byte buf[4]; + png_size_t size; + + png_debug(1, "in png_write_sBIT"); + + /* Make sure we don't depend upon the order of PNG_COLOR_8 */ + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_byte maxbits; + + maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : + png_ptr->usr_bit_depth); + + if (sbit->red == 0 || sbit->red > maxbits || + sbit->green == 0 || sbit->green > maxbits || + sbit->blue == 0 || sbit->blue > maxbits) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->red; + buf[1] = sbit->green; + buf[2] = sbit->blue; + size = 3; + } + + else + { + if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->gray; + size = 1; + } + + if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) + { + if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[size++] = sbit->alpha; + } + + png_write_complete_chunk(png_ptr, png_sBIT, buf, size); +} +#endif + +#ifdef PNG_WRITE_cHRM_SUPPORTED +/* Write the cHRM chunk */ +void /* PRIVATE */ +png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy) +{ + png_byte buf[32]; + + png_debug(1, "in png_write_cHRM"); + + /* Each value is saved in 1/100,000ths */ + png_save_int_32(buf, xy->whitex); + png_save_int_32(buf + 4, xy->whitey); + + png_save_int_32(buf + 8, xy->redx); + png_save_int_32(buf + 12, xy->redy); + + png_save_int_32(buf + 16, xy->greenx); + png_save_int_32(buf + 20, xy->greeny); + + png_save_int_32(buf + 24, xy->bluex); + png_save_int_32(buf + 28, xy->bluey); + + png_write_complete_chunk(png_ptr, png_cHRM, buf, 32); +} +#endif + +#ifdef PNG_WRITE_tRNS_SUPPORTED +/* Write the tRNS chunk */ +void /* PRIVATE */ +png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha, + png_const_color_16p tran, int num_trans, int color_type) +{ + png_byte buf[6]; + + png_debug(1, "in png_write_tRNS"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) + { + png_app_warning(png_ptr, + "Invalid number of transparent colors specified"); + return; + } + + /* Write the chunk out as it is */ + png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, + (png_size_t)num_trans); + } + + else if (color_type == PNG_COLOR_TYPE_GRAY) + { + /* One 16-bit value */ + if (tran->gray >= (1 << png_ptr->bit_depth)) + { + png_app_warning(png_ptr, + "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, tran->gray); + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); + } + + else if (color_type == PNG_COLOR_TYPE_RGB) + { + /* Three 16-bit values */ + png_save_uint_16(buf, tran->red); + png_save_uint_16(buf + 2, tran->green); + png_save_uint_16(buf + 4, tran->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) +#else + if ((buf[0] | buf[2] | buf[4]) != 0) +#endif + { + png_app_warning(png_ptr, + "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); + return; + } + + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); + } + + else + { + png_app_warning(png_ptr, "Can't write tRNS with an alpha channel"); + } +} +#endif + +#ifdef PNG_WRITE_bKGD_SUPPORTED +/* Write the background chunk */ +void /* PRIVATE */ +png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type) +{ + png_byte buf[6]; + + png_debug(1, "in png_write_bKGD"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + (png_ptr->num_palette != 0 || + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) && +#endif + back->index >= png_ptr->num_palette) + { + png_warning(png_ptr, "Invalid background palette index"); + return; + } + + buf[0] = back->index; + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); + } + + else if ((color_type & PNG_COLOR_MASK_COLOR) != 0) + { + png_save_uint_16(buf, back->red); + png_save_uint_16(buf + 2, back->green); + png_save_uint_16(buf + 4, back->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) +#else + if ((buf[0] | buf[2] | buf[4]) != 0) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); + + return; + } + + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); + } + + else + { + if (back->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, back->gray); + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); + } +} +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED +/* Write the histogram */ +void /* PRIVATE */ +png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist) +{ + int i; + png_byte buf[3]; + + png_debug(1, "in png_write_hIST"); + + if (num_hist > (int)png_ptr->num_palette) + { + png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, + png_ptr->num_palette); + + png_warning(png_ptr, "Invalid number of histogram entries specified"); + return; + } + + png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + + for (i = 0; i < num_hist; i++) + { + png_save_uint_16(buf, hist[i]); + png_write_chunk_data(png_ptr, buf, (png_size_t)2); + } + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_tEXt_SUPPORTED +/* Write a tEXt chunk */ +void /* PRIVATE */ +png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, + png_size_t text_len) +{ + png_uint_32 key_len; + png_byte new_key[80]; + + png_debug(1, "in png_write_tEXt"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "tEXt: invalid keyword"); + + if (text == NULL || *text == '\0') + text_len = 0; + + else + text_len = strlen(text); + + if (text_len > PNG_UINT_31_MAX - (key_len+1)) + png_error(png_ptr, "tEXt: text too long"); + + /* Make sure we include the 0 after the key */ + png_write_chunk_header(png_ptr, png_tEXt, + (png_uint_32)/*checked above*/(key_len + text_len + 1)); + /* + * We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, new_key, key_len + 1); + + if (text_len != 0) + png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len); + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_zTXt_SUPPORTED +/* Write a compressed text chunk */ +void /* PRIVATE */ +png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, + int compression) +{ + png_uint_32 key_len; + png_byte new_key[81]; + compression_state comp; + + png_debug(1, "in png_write_zTXt"); + + if (compression == PNG_TEXT_COMPRESSION_NONE) + { + png_write_tEXt(png_ptr, key, text, 0); + return; + } + + if (compression != PNG_TEXT_COMPRESSION_zTXt) + png_error(png_ptr, "zTXt: invalid compression type"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "zTXt: invalid keyword"); + + /* Add the compression method and 1 for the keyword separator. */ + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; + ++key_len; + + /* Compute the compressed data; do it now for the length */ + png_text_compress_init(&comp, (png_const_bytep)text, + text == NULL ? 0 : strlen(text)); + + if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + /* Write start of chunk */ + png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len); + + /* Write key */ + png_write_chunk_data(png_ptr, new_key, key_len); + + /* Write the compressed data */ + png_write_compressed_data_out(png_ptr, &comp); + + /* Close the chunk */ + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_iTXt_SUPPORTED +/* Write an iTXt chunk */ +void /* PRIVATE */ +png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key, + png_const_charp lang, png_const_charp lang_key, png_const_charp text) +{ + png_uint_32 key_len, prefix_len; + png_size_t lang_len, lang_key_len; + png_byte new_key[82]; + compression_state comp; + + png_debug(1, "in png_write_iTXt"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "iTXt: invalid keyword"); + + /* Set the compression flag */ + switch (compression) + { + case PNG_ITXT_COMPRESSION_NONE: + case PNG_TEXT_COMPRESSION_NONE: + compression = new_key[++key_len] = 0; /* no compression */ + break; + + case PNG_TEXT_COMPRESSION_zTXt: + case PNG_ITXT_COMPRESSION_zTXt: + compression = new_key[++key_len] = 1; /* compressed */ + break; + + default: + png_error(png_ptr, "iTXt: invalid compression"); + } + + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; + ++key_len; /* for the keywod separator */ + + /* We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG, however, + * specifies that the text is UTF-8 and this really doesn't require any + * checking. + * + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + * + * TODO: validate the language tag correctly (see the spec.) + */ + if (lang == NULL) lang = ""; /* empty language is valid */ + lang_len = strlen(lang)+1; + if (lang_key == NULL) lang_key = ""; /* may be empty */ + lang_key_len = strlen(lang_key)+1; + if (text == NULL) text = ""; /* may be empty */ + + prefix_len = key_len; + if (lang_len > PNG_UINT_31_MAX-prefix_len) + prefix_len = PNG_UINT_31_MAX; + else + prefix_len = (png_uint_32)(prefix_len + lang_len); + + if (lang_key_len > PNG_UINT_31_MAX-prefix_len) + prefix_len = PNG_UINT_31_MAX; + else + prefix_len = (png_uint_32)(prefix_len + lang_key_len); + + png_text_compress_init(&comp, (png_const_bytep)text, strlen(text)); + + if (compression != 0) + { + if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + } + + else + { + if (comp.input_len > PNG_UINT_31_MAX-prefix_len) + png_error(png_ptr, "iTXt: uncompressed text too long"); + + /* So the string will fit in a chunk: */ + comp.output_len = (png_uint_32)/*SAFE*/comp.input_len; + } + + png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len); + + png_write_chunk_data(png_ptr, new_key, key_len); + + png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len); + + png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len); + + if (compression != 0) + png_write_compressed_data_out(png_ptr, &comp); + + else + png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len); + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED +/* Write the oFFs chunk */ +void /* PRIVATE */ +png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset, + int unit_type) +{ + png_byte buf[9]; + + png_debug(1, "in png_write_oFFs"); + + if (unit_type >= PNG_OFFSET_LAST) + png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); + + png_save_int_32(buf, x_offset); + png_save_int_32(buf + 4, y_offset); + buf[8] = (png_byte)unit_type; + + png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); +} +#endif +#ifdef PNG_WRITE_pCAL_SUPPORTED +/* Write the pCAL chunk (described in the PNG extensions document) */ +void /* PRIVATE */ +png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0, + png_int_32 X1, int type, int nparams, png_const_charp units, + png_charpp params) +{ + png_uint_32 purpose_len; + png_size_t units_len, total_len; + png_size_tp params_len; + png_byte buf[10]; + png_byte new_purpose[80]; + int i; + + png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); + + if (type >= PNG_EQUATION_LAST) + png_error(png_ptr, "Unrecognized equation type for pCAL chunk"); + + purpose_len = png_check_keyword(png_ptr, purpose, new_purpose); + + if (purpose_len == 0) + png_error(png_ptr, "pCAL: invalid keyword"); + + ++purpose_len; /* terminator */ + + png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); + units_len = strlen(units) + (nparams == 0 ? 0 : 1); + png_debug1(3, "pCAL units length = %d", (int)units_len); + total_len = purpose_len + units_len + 10; + + params_len = (png_size_tp)png_malloc(png_ptr, + (png_alloc_size_t)(nparams * (sizeof (png_size_t)))); + + /* Find the length of each parameter, making sure we don't count the + * null terminator for the last parameter. + */ + for (i = 0; i < nparams; i++) + { + params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1); + png_debug2(3, "pCAL parameter %d length = %lu", i, + (unsigned long)params_len[i]); + total_len += params_len[i]; + } + + png_debug1(3, "pCAL total length = %d", (int)total_len); + png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len); + png_write_chunk_data(png_ptr, new_purpose, purpose_len); + png_save_int_32(buf, X0); + png_save_int_32(buf + 4, X1); + buf[8] = (png_byte)type; + buf[9] = (png_byte)nparams; + png_write_chunk_data(png_ptr, buf, (png_size_t)10); + png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); + + for (i = 0; i < nparams; i++) + { + png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]); + } + + png_free(png_ptr, params_len); + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED +/* Write the sCAL chunk */ +void /* PRIVATE */ +png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width, + png_const_charp height) +{ + png_byte buf[64]; + png_size_t wlen, hlen, total_len; + + png_debug(1, "in png_write_sCAL_s"); + + wlen = strlen(width); + hlen = strlen(height); + total_len = wlen + hlen + 2; + + if (total_len > 64) + { + png_warning(png_ptr, "Can't write sCAL (buffer too small)"); + return; + } + + buf[0] = (png_byte)unit; + memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ + memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ + + png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); + png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len); +} +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +/* Write the pHYs chunk */ +void /* PRIVATE */ +png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit, + png_uint_32 y_pixels_per_unit, + int unit_type) +{ + png_byte buf[9]; + + png_debug(1, "in png_write_pHYs"); + + if (unit_type >= PNG_RESOLUTION_LAST) + png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); + + png_save_uint_32(buf, x_pixels_per_unit); + png_save_uint_32(buf + 4, y_pixels_per_unit); + buf[8] = (png_byte)unit_type; + + png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); +} +#endif + +#ifdef PNG_WRITE_tIME_SUPPORTED +/* Write the tIME chunk. Use either png_convert_from_struct_tm() + * or png_convert_from_time_t(), or fill in the structure yourself. + */ +void /* PRIVATE */ +png_write_tIME(png_structrp png_ptr, png_const_timep mod_time) +{ + png_byte buf[7]; + + png_debug(1, "in png_write_tIME"); + + if (mod_time->month > 12 || mod_time->month < 1 || + mod_time->day > 31 || mod_time->day < 1 || + mod_time->hour > 23 || mod_time->second > 60) + { + png_warning(png_ptr, "Invalid time specified for tIME chunk"); + return; + } + + png_save_uint_16(buf, mod_time->year); + buf[2] = mod_time->month; + buf[3] = mod_time->day; + buf[4] = mod_time->hour; + buf[5] = mod_time->minute; + buf[6] = mod_time->second; + + png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7); +} +#endif + +/* Initializes the row writing capability of libpng */ +void /* PRIVATE */ +png_write_start_row(png_structrp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + png_alloc_size_t buf_size; + int usr_pixel_depth; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_byte filters; +#endif + + png_debug(1, "in png_write_start_row"); + + usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; + buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; + + /* 1.5.6: added to allow checking in the row write code. */ + png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; + png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; + + /* Set up row buffer */ + png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); + + png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + filters = png_ptr->do_filter; + + if (png_ptr->height == 1) + filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (png_ptr->width == 1) + filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (filters == 0) + filters = PNG_FILTER_NONE; + + png_ptr->do_filter = filters; + + if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG | + PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL) + { + int num_filters = 0; + + png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); + + if (filters & PNG_FILTER_SUB) + num_filters++; + + if (filters & PNG_FILTER_UP) + num_filters++; + + if (filters & PNG_FILTER_AVG) + num_filters++; + + if (filters & PNG_FILTER_PAETH) + num_filters++; + + if (num_filters > 1) + png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr, + buf_size)); + } + + /* We only need to keep the previous row if we are using one of the following + * filters. + */ + if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0) + png_ptr->prev_row = png_voidcast(png_bytep, + png_calloc(png_ptr, buf_size)); +#endif /* WRITE_FILTER */ + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, we need to set up width and height of pass */ + if (png_ptr->interlaced != 0) + { + if ((png_ptr->transformations & PNG_INTERLACE) == 0) + { + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + + png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - + png_pass_start[0]) / png_pass_inc[0]; + } + + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + } + + else +#endif + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } +} + +/* Internal use only. Called when finished processing a row of data. */ +void /* PRIVATE */ +png_write_finish_row(png_structrp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + png_debug(1, "in png_write_finish_row"); + + /* Next row */ + png_ptr->row_number++; + + /* See if we are done */ + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, go to next pass */ + if (png_ptr->interlaced != 0) + { + png_ptr->row_number = 0; + if ((png_ptr->transformations & PNG_INTERLACE) != 0) + { + png_ptr->pass++; + } + + else + { + /* Loop until we find a non-zero width or height pass */ + do + { + png_ptr->pass++; + + if (png_ptr->pass >= 7) + break; + + png_ptr->usr_width = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + + if ((png_ptr->transformations & PNG_INTERLACE) != 0) + break; + + } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); + + } + + /* Reset the row above the image for the next pass */ + if (png_ptr->pass < 7) + { + if (png_ptr->prev_row != NULL) + memset(png_ptr->prev_row, 0, + (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* + png_ptr->usr_bit_depth, png_ptr->width)) + 1); + + return; + } + } +#endif + + /* If we get here, we've just written the last row, so we need + to flush the compressor */ + png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH); +} + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +/* Pick out the correct pixels for the interlace pass. + * The basic idea here is to go through the row with a source + * pointer and a destination pointer (sp and dp), and copy the + * correct pixels for the pass. As the row gets compacted, + * sp will always be >= dp, so we should never overwrite anything. + * See the default: case for the easiest code to understand. + */ +void /* PRIVATE */ +png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_write_interlace"); + + /* We don't have to do anything on the last pass (6) */ + if (pass < 6) + { + /* Each pixel depth is handled separately */ + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp; + png_bytep dp; + unsigned int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + d = 0; + shift = 7; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 3); + value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; + d |= (value << shift); + + if (shift == 0) + { + shift = 7; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift--; + + } + if (shift != 7) + *dp = (png_byte)d; + + break; + } + + case 2: + { + png_bytep sp; + png_bytep dp; + unsigned int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 6; + d = 0; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 2); + value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; + d |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 2; + } + if (shift != 6) + *dp = (png_byte)d; + + break; + } + + case 4: + { + png_bytep sp; + png_bytep dp; + unsigned int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 4; + d = 0; + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 1); + value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; + d |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 4; + } + if (shift != 4) + *dp = (png_byte)d; + + break; + } + + default: + { + png_bytep sp; + png_bytep dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + png_size_t pixel_bytes; + + /* Start at the beginning */ + dp = row; + + /* Find out how many bytes each pixel takes up */ + pixel_bytes = (row_info->pixel_depth >> 3); + + /* Loop through the row, only looking at the pixels that matter */ + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + /* Find out where the original pixel is */ + sp = row + (png_size_t)i * pixel_bytes; + + /* Move the pixel */ + if (dp != sp) + memcpy(dp, sp, pixel_bytes); + + /* Next pixel */ + dp += pixel_bytes; + } + break; + } + } + /* Set new row width */ + row_info->width = (row_info->width + + png_pass_inc[pass] - 1 - + png_pass_start[pass]) / + png_pass_inc[pass]; + + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); + } +} +#endif + + +/* This filters the row, chooses which filter to use, if it has not already + * been specified by the application, and then writes the row out with the + * chosen filter. + */ +static void /* PRIVATE */ +png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, + png_size_t row_bytes); + +#ifdef PNG_WRITE_FILTER_SUPPORTED +static png_size_t /* PRIVATE */ +png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp, + const png_size_t row_bytes, const png_size_t lmins) +{ + png_bytep rp, dp, lp; + png_size_t i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp; + i++, rp++, dp++) + { + v = *dp = *rp; + sum += (v < 128) ? v : 256 - v; + } + + for (lp = png_ptr->row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} + +static png_size_t /* PRIVATE */ +png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes, + const png_size_t lmins) +{ + png_bytep rp, dp, pp; + png_size_t i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_UP; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < row_bytes; + i++, rp++, pp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} + +static png_size_t /* PRIVATE */ +png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp, + const png_size_t row_bytes, const png_size_t lmins) +{ + png_bytep rp, dp, pp, lp; + png_uint_32 i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = png_ptr->row_buf + 1; i < row_bytes; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) + & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} + +static png_size_t /* PRIVATE */ +png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp, + const png_size_t row_bytes, const png_size_t lmins) +{ + png_bytep rp, dp, pp, cp, lp; + png_size_t i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes; + i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; + + v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + + return (sum); +} +#endif /* WRITE_FILTER */ + +void /* PRIVATE */ +png_write_find_filter(png_structrp png_ptr, png_row_infop row_info) +{ +#ifndef PNG_WRITE_FILTER_SUPPORTED + png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1); +#else + png_byte filter_to_do = png_ptr->do_filter; + png_bytep row_buf; + png_bytep best_row; + png_uint_32 bpp; + png_size_t mins; + png_size_t row_bytes = row_info->rowbytes; + + png_debug(1, "in png_write_find_filter"); + + /* Find out how many bytes offset each pixel is */ + bpp = (row_info->pixel_depth + 7) >> 3; + + row_buf = png_ptr->row_buf; + mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the + running sum */; + + /* The prediction method we use is to find which method provides the + * smallest value when summing the absolute values of the distances + * from zero, using anything >= 128 as negative numbers. This is known + * as the "minimum sum of absolute differences" heuristic. Other + * heuristics are the "weighted minimum sum of absolute differences" + * (experimental and can in theory improve compression), and the "zlib + * predictive" method (not implemented yet), which does test compressions + * of lines using different filter methods, and then chooses the + * (series of) filter(s) that give minimum compressed data size (VERY + * computationally expensive). + * + * GRR 980525: consider also + * + * (1) minimum sum of absolute differences from running average (i.e., + * keep running sum of non-absolute differences & count of bytes) + * [track dispersion, too? restart average if dispersion too large?] + * + * (1b) minimum sum of absolute differences from sliding average, probably + * with window size <= deflate window (usually 32K) + * + * (2) minimum sum of squared differences from zero or running average + * (i.e., ~ root-mean-square approach) + */ + + + /* We don't need to test the 'no filter' case if this is the only filter + * that has been chosen, as it doesn't actually do anything to the data. + */ + best_row = png_ptr->row_buf; + + + if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE) + { + png_bytep rp; + png_size_t sum = 0; + png_size_t i; + int v; + + if (PNG_SIZE_MAX/128 <= row_bytes) + { + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + { + /* Check for overflow */ + if (sum > PNG_SIZE_MAX/128 - 256) + break; + + v = *rp; + sum += (v < 128) ? v : 256 - v; + } + } + else /* Overflow is not possible */ + { + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + { + v = *rp; + sum += (v < 128) ? v : 256 - v; + } + } + + mins = sum; + } + + /* Sub filter */ + if (filter_to_do == PNG_FILTER_SUB) + /* It's the only filter so no testing is needed */ + { + (void) png_setup_sub_row(png_ptr, bpp, row_bytes, mins); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_SUB) != 0) + { + png_size_t sum; + png_size_t lmins = mins; + + sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins); + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Up filter */ + if (filter_to_do == PNG_FILTER_UP) + { + (void) png_setup_up_row(png_ptr, row_bytes, mins); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_UP) != 0) + { + png_size_t sum; + png_size_t lmins = mins; + + sum = png_setup_up_row(png_ptr, row_bytes, lmins); + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Avg filter */ + if (filter_to_do == PNG_FILTER_AVG) + { + (void) png_setup_avg_row(png_ptr, bpp, row_bytes, mins); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_AVG) != 0) + { + png_size_t sum; + png_size_t lmins = mins; + + sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins); + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Paeth filter */ + if ((filter_to_do == PNG_FILTER_PAETH) != 0) + { + (void) png_setup_paeth_row(png_ptr, bpp, row_bytes, mins); + best_row = png_ptr->try_row; + } + + else if ((filter_to_do & PNG_FILTER_PAETH) != 0) + { + png_size_t sum; + png_size_t lmins = mins; + + sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins); + + if (sum < mins) + { + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } + } + } + + /* Do the actual writing of the filtered row data from the chosen filter. */ + png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1); + +#endif /* WRITE_FILTER */ +} + + +/* Do the actual writing of a previously filtered row. */ +static void +png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, + png_size_t full_row_length/*includes filter byte*/) +{ + png_debug(1, "in png_write_filtered_row"); + + png_debug1(2, "filter = %d", filtered_row[0]); + + png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH); + +#ifdef PNG_WRITE_FILTER_SUPPORTED + /* Swap the current and previous rows */ + if (png_ptr->prev_row != NULL) + { + png_bytep tptr; + + tptr = png_ptr->prev_row; + png_ptr->prev_row = png_ptr->row_buf; + png_ptr->row_buf = tptr; + } +#endif /* WRITE_FILTER */ + + /* Finish row - updates counters and flushes zlib if last row */ + png_write_finish_row(png_ptr); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->flush_rows++; + + if (png_ptr->flush_dist > 0 && + png_ptr->flush_rows >= png_ptr->flush_dist) + { + png_write_flush(png_ptr); + } +#endif /* WRITE_FLUSH */ +} +#endif /* WRITE */ |