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Diffstat (limited to 'thirdparty/basis_universal/encoder/pvpngreader.cpp')
| -rw-r--r-- | thirdparty/basis_universal/encoder/pvpngreader.cpp | 2662 |
1 files changed, 2662 insertions, 0 deletions
diff --git a/thirdparty/basis_universal/encoder/pvpngreader.cpp b/thirdparty/basis_universal/encoder/pvpngreader.cpp new file mode 100644 index 0000000000..46639f2796 --- /dev/null +++ b/thirdparty/basis_universal/encoder/pvpngreader.cpp @@ -0,0 +1,2662 @@ +// pngreader.cpp - Public Domain - see unlicense at bottom of file. +// +// Notes: +// This is ancient code from ~1995 ported to C++. It was originally written for a +// DOS app with very limited memory. It's not as fast as it should be, but it works. +// The low-level PNG reader class was written assuming the PNG file could not fit +// entirely into memory, which dictated how it was written/structured. +// It has been modified to use either zlib or miniz. +// It supports all PNG color types/bit depths/interlacing, however 16-bit/component +// images are converted to 8-bit. +// TRNS chunks are converted to alpha as needed. +// GAMA chunk is read, but not applied. + +#include "../transcoder/basisu.h" + +#define MINIZ_HEADER_FILE_ONLY +#define MINIZ_NO_ZLIB_COMPATIBLE_NAMES +#include "basisu_miniz.h" + +#include "pvpngreader.h" + +#include <stdlib.h> +#include <stdio.h> +#include <math.h> +#include <string.h> +#include <vector> +#include <assert.h> + +#define PVPNG_IDAT_CRC_CHECKING (1) +#define PVPNG_ADLER32_CHECKING (1) + +namespace pv_png +{ + +const uint32_t MIN_PNG_SIZE = 8 + 13 + 8 + 1 + 4 + 12; + +template <typename S> inline S maximum(S a, S b) { return (a > b) ? a : b; } +template <typename S> inline S minimum(S a, S b) { return (a < b) ? a : b; } + +template <typename T> inline void clear_obj(T& obj) { memset(&obj, 0, sizeof(obj)); } + +#define MAX_SUPPORTED_RES (32768) +#define FALSE (0) +#define TRUE (1) +#define PNG_MAX_ALLOC_BLOCKS (16) + +enum +{ + PNG_DECERROR = -3, + PNG_ALLDONE = -5, + PNG_READPASTEOF = -11, + PNG_UNKNOWNTYPE = -16, + PNG_FILEREADERROR = -17, + PNG_NOTENOUGHMEM = -108, + PNG_BAD_CHUNK_CRC32 = -13000, + PNG_NO_IHDR = -13001, + PNG_BAD_WIDTH = -13002, + PNG_BAD_HEIGHT = -13003, + PNG_UNS_COMPRESSION = -13004, + PNG_UNS_FILTER = -13005, + PNG_UNS_ILACE = -13006, + PNG_UNS_COLOR_TYPE = -13007, + PNG_BAD_BIT_DEPTH = -13008, + PNG_BAD_CHUNK_SIZE = -13009, + PNG_UNS_CRITICAL_CHUNK = -13010, + PNG_BAD_TRNS_CHUNK = -13011, + PNG_BAD_PLTE_CHUNK = -13012, + PNG_UNS_RESOLUTION = -13013, + PNG_INVALID_DATA_STREAM = -13014, + PNG_MISSING_PALETTE = -13015, + PNG_UNS_PREDICTOR = -13016, + PNG_INCOMPLETE_IMAGE = -13017, + PNG_TOO_MUCH_DATA = -13018 +}; + +#define PNG_COLOR_TYPE_PAL_MASK (1) +#define PNG_COLOR_TYPE_COL_MASK (2) +#define PNG_COLOR_TYPE_ALP_MASK (4) + +#define PNG_INFLATE_SRC_BUF_SIZE (4096) + +struct ihdr_struct +{ + uint32_t m_width; + uint32_t m_height; + uint8_t m_bit_depth; + uint8_t m_color_type; + uint8_t m_comp_type; + uint8_t m_filter_type; + uint8_t m_ilace_type; +}; + +class png_file +{ +public: + png_file() { } + virtual ~png_file() { } + + virtual bool resize(uint64_t new_size) = 0; + virtual uint64_t get_size() = 0; + virtual uint64_t tell() = 0; + virtual bool seek(uint64_t ofs) = 0; + virtual size_t write(const void* pBuf, size_t len) = 0; + virtual size_t read(void* pBuf, size_t len) = 0; +}; + +class png_memory_file : public png_file +{ +public: + std::vector<uint8_t> m_buf; + uint64_t m_ofs; + + png_memory_file() : + png_file(), + m_ofs(0) + { + } + + virtual ~png_memory_file() + { + } + + std::vector<uint8_t>& get_buf() { return m_buf; } + const std::vector<uint8_t>& get_buf() const { return m_buf; } + + void init() + { + m_ofs = 0; + m_buf.resize(0); + } + + virtual bool resize(uint64_t new_size) + { + if ((sizeof(size_t) == sizeof(uint32_t)) && (new_size >= 0x7FFFFFFF)) + return false; + + m_buf.resize((size_t)new_size); + m_ofs = m_buf.size(); + + return true; + } + + virtual uint64_t get_size() + { + return m_buf.size(); + } + + virtual uint64_t tell() + { + return m_ofs; + } + + virtual bool seek(uint64_t ofs) + { + m_ofs = ofs; + return true; + } + + virtual size_t write(const void* pBuf, size_t len) + { + uint64_t new_size = m_ofs + len; + if (new_size > m_buf.size()) + { + if ((sizeof(size_t) == sizeof(uint32_t)) && (new_size > 0x7FFFFFFFUL)) + return 0; + m_buf.resize(new_size); + } + + memcpy(&m_buf[(size_t)m_ofs], pBuf, len); + m_ofs += len; + + return len; + } + + virtual size_t read(void* pBuf, size_t len) + { + if (m_ofs >= m_buf.size()) + return 0; + + uint64_t max_bytes = minimum<uint64_t>(len, m_buf.size() - m_ofs); + memcpy(pBuf, &m_buf[(size_t)m_ofs], max_bytes); + + m_ofs += max_bytes; + + return max_bytes; + } +}; + +class png_readonly_memory_file : public png_file +{ +public: + const uint8_t* m_pBuf; + size_t m_buf_size; + uint64_t m_ofs; + + png_readonly_memory_file() : + png_file(), + m_pBuf(nullptr), + m_buf_size(0), + m_ofs(0) + { + } + + virtual ~png_readonly_memory_file() + { + } + + void init(const void *pBuf, size_t buf_size) + { + m_pBuf = static_cast<const uint8_t*>(pBuf); + m_buf_size = buf_size; + m_ofs = 0; + } + + virtual bool resize(uint64_t new_size) + { + (void)new_size; + assert(0); + return false; + } + + virtual uint64_t get_size() + { + return m_buf_size; + } + + virtual uint64_t tell() + { + return m_ofs; + } + + virtual bool seek(uint64_t ofs) + { + m_ofs = ofs; + return true; + } + + virtual size_t write(const void* pBuf, size_t len) + { + (void)pBuf; + (void)len; + assert(0); + return 0; + } + + virtual size_t read(void* pBuf, size_t len) + { + if (m_ofs >= m_buf_size) + return 0; + + uint64_t max_bytes = minimum<uint64_t>(len, m_buf_size - m_ofs); + memcpy(pBuf, &m_pBuf[(size_t)m_ofs], max_bytes); + + m_ofs += max_bytes; + + return max_bytes; + } +}; + +#ifdef _MSC_VER +#define ftell64 _ftelli64 +#define fseek64 _fseeki64 +#else +#define ftell64 ftello +#define fseek64 fseeko +#endif + +class png_cfile : public png_file +{ +public: + FILE* m_pFile; + + png_cfile() : + png_file(), + m_pFile(nullptr) + { + } + + virtual ~png_cfile() + { + close(); + } + + bool init(const char *pFilename, const char *pMode) + { + close(); + + m_pFile = nullptr; + +#ifdef _MSC_VER + fopen_s(&m_pFile, pFilename, pMode); +#else + m_pFile = fopen(pFilename, pMode); +#endif + + return m_pFile != nullptr; + } + + bool close() + { + bool status = true; + if (m_pFile) + { + if (fclose(m_pFile) == EOF) + status = false; + m_pFile = nullptr; + } + return status; + } + + virtual bool resize(uint64_t new_size) + { + if (new_size) + { + if (!seek(new_size - 1)) + return false; + + int v = 0; + if (write(&v, 1) != 1) + return false; + } + else + { + if (!seek(0)) + return false; + } + + return true; + } + + virtual uint64_t get_size() + { + int64_t cur_ofs = ftell64(m_pFile); + if (cur_ofs < 0) + return 0; + + if (fseek64(m_pFile, 0, SEEK_END) != 0) + return 0; + + const int64_t cur_size = ftell64(m_pFile); + if (cur_size < 0) + return 0; + + if (fseek64(m_pFile, cur_ofs, SEEK_SET) != 0) + return 0; + + return cur_size; + } + + virtual uint64_t tell() + { + int64_t cur_ofs = ftell64(m_pFile); + if (cur_ofs < 0) + return 0; + + return cur_ofs; + } + + virtual bool seek(uint64_t ofs) + { + return fseek64(m_pFile, ofs, SEEK_SET) == 0; + } + + virtual size_t write(const void* pBuf, size_t len) + { + return (size_t)fwrite(pBuf, 1, len, m_pFile); + } + + virtual size_t read(void* pBuf, size_t len) + { + return (size_t)fread(pBuf, 1, len, m_pFile); + } +}; + +// This low-level helper class handles the actual decoding of PNG files. +class png_decoder +{ +public: + png_decoder(); + ~png_decoder(); + + // Scans the PNG file, but doesn't decode the IDAT data. + // Returns 0 on success, or an error code. + // If the returned status is non-zero, or m_img_supported_flag==FALSE the image either the image is corrupted/not PNG or is unsupported in some way. + int png_scan(png_file *pFile); + + // Decodes a single scanline of PNG image data. + // Returns a pointer to the scanline's pixel data and its size in bytes. + // This data is only minimally processed from the internal PNG pixel data. + // The caller must use the ihdr, trns_flag and values, and the palette to actually decode the pixel data. + // + // Possible returned pixel formats is somewhat complex due to the history of this code: + // 8-bit RGBA, always 4 bytes/pixel - 24bpp PNG's are converted to 32bpp and TRNS processing is done automatically (8/16bpp RGB or RGBA PNG files) + // 1/2/4/8-bit grayscale, 1 byte per pixel - must convert to [0,255] using the palette or some other means, must optionally use the TRNS chunk for alpha (1/2/4/8 Grayscale PNG files - not 16bpp though!) + // 1/2/4/8-bit palettized, 1 byte per pixel - must convert to RGB using the 24bpp palette and optionally the TRNS chunk for alpha (1/2/4/8bpp palettized PNG files) + // 8-bit grayscale with alpha, 2 bytes per pixel - TRNS processing will be done for you on 16bpp images (there's a special case here for 16bpp Grey files) (8/16bpp Gray-Alpha *or 16bpp Grayscale* PNG files) + // + // Returns 0 on success, a non-zero error code, or PNG_ALLDONE. + int png_decode(void** ppImg_ptr, uint32_t* pImg_len); + + // Starts decoding. Returns 0 on success, otherwise an error code. + int png_decode_start(); + + // Deinitializes the decoder, freeing all allocations. + void png_decode_end(); + + png_file* m_pFile; + + // Image's 24bpp palette - 3 bytes per entry + uint8_t m_plte_flag; + uint8_t m_img_pal[768]; + + int m_img_supported_flag; + + ihdr_struct m_ihdr; + + uint8_t m_chunk_flag; + uint32_t m_chunk_size; + uint32_t m_chunk_left; + uint32_t m_chunk_crc32; + uint8_t m_chunk_name[4]; + + uint8_t m_end_of_idat_chunks; + + void* m_pMalloc_blocks[PNG_MAX_ALLOC_BLOCKS]; + + uint32_t m_dec_bytes_per_pixel; // bytes per pixel decoded from the PNG file (minimum 1 for 1/2/4 bpp), factors in the PNG 8/16 bit/component bit depth, may be up to 8 bytes (2*4) + uint32_t m_dst_bytes_per_pixel; // bytes per pixel returned to the caller (1-4), always has alpha if the PNG has alpha, 16-bit components always converted to 8-bits/component + + uint32_t m_dec_bytes_per_line; // bytes per line decoded from the PNG file (before 1/2/4 expansion), +1 for the filter byte + uint32_t m_src_bytes_per_line; // decoded PNG bytes per line, before 1/2/4 bpp expansion, not counting the filter byte, updated during adam7 deinterlacing + uint32_t m_dst_bytes_per_line; // bytes per line returned to the caller (1-4 times width) + + int (*m_pProcess_func)(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi); + + uint8_t* m_pPre_line_buf; + uint8_t* m_pCur_line_buf; + uint8_t* m_pPro_line_buf; + + uint8_t m_bkgd_flag; + uint32_t m_bkgd_value[3]; + + uint8_t m_gama_flag; + uint32_t m_gama_value; + + uint8_t m_trns_flag; + uint32_t m_trns_value[256]; + + buminiz::mz_stream m_inflator; + + uint8_t inflate_src_buf[PNG_INFLATE_SRC_BUF_SIZE]; + + uint32_t m_inflate_src_buf_ofs; + uint32_t m_inflate_src_buf_size; + uint32_t m_inflate_dst_buf_ofs; + + int m_inflate_eof_flag; + + uint8_t m_gamma_table[256]; + + int m_pass_x_size; + int m_pass_y_left; + + int m_adam7_pass_num; + int m_adam7_pass_y; + int m_adam7_pass_size_x[7]; + int m_adam7_pass_size_y[7]; + + std::vector<uint8_t> m_adam7_image_buf; + + int m_adam7_decoded_flag; + + bool m_scanned_flag; + + int m_terminate_status; + +#define TEMP_BUF_SIZE (384) + uint8_t m_temp_buf[TEMP_BUF_SIZE * 4]; + + void clear(); + void uninitialize(); + int terminate(int status); + void* png_malloc(uint32_t i); + void* png_calloc(uint32_t i); + int block_read(void* buf, uint32_t len); + int64_t block_read_dword(); + int fetch_next_chunk_data(uint8_t* buf, int bytes); + int fetch_next_chunk_byte(); + int fetch_next_chunk_word(); + int64_t fetch_next_chunk_dword(); + int fetch_next_chunk_init(); + int unchunk_data(uint8_t* buf, uint32_t bytes, uint32_t* ptr_bytes_read); + inline void adam7_write_pixel_8(int x, int y, int c); + inline void adam7_write_pixel_16(int x, int y, int r, int g); + inline void adam7_write_pixel_24(int x, int y, int r, int g, int b); + inline void adam7_write_pixel_32(int x, int y, int r, int g, int b, int a); + void unpredict_sub(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp); + void unpredict_up(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp); + void unpredict_average(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp); + inline uint8_t paeth_predictor(int a, int b, int c); + void unpredict_paeth(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp); + int adam7_pass_size(int size, int start, int step); + int decompress_line(uint32_t* bytes_decoded); + int find_iend_chunk(); + void calc_gamma_table(); + void create_grey_palette(); + int read_signature(); + int read_ihdr_chunk(); + int read_bkgd_chunk(); + int read_gama_chunk(); + int read_trns_chunk(); + int read_plte_chunk(); + int find_idat_chunk(); +}; + +void png_decoder::uninitialize() +{ + m_pFile = nullptr; + + for (int i = 0; i < PNG_MAX_ALLOC_BLOCKS; i++) + { + free(m_pMalloc_blocks[i]); + m_pMalloc_blocks[i] = nullptr; + } + + mz_inflateEnd(&m_inflator); +} + +int png_decoder::terminate(int status) +{ + if (m_terminate_status == 0) + m_terminate_status = status; + + uninitialize(); + return status; +} + +void* png_decoder::png_malloc(uint32_t len) +{ + if (!len) + len++; + + void* p = malloc(len); + + if (!p) + return nullptr; + + int j; + for (j = 0; j < PNG_MAX_ALLOC_BLOCKS; j++) + if (!m_pMalloc_blocks[j]) + break; + + if (j == PNG_MAX_ALLOC_BLOCKS) + return nullptr; + + m_pMalloc_blocks[j] = p; + + return p; +} + +void* png_decoder::png_calloc(uint32_t len) +{ + void* p = png_malloc(len); + if (!p) + return nullptr; + + if (p) + memset(p, 0, len); + + return p; +} + +int png_decoder::block_read(void* buf, uint32_t len) +{ + size_t bytes_read = m_pFile->read(buf, len); + if (bytes_read != len) + return terminate(PNG_READPASTEOF); + return 0; +} + +int64_t png_decoder::block_read_dword() +{ + uint8_t buf[4]; + + int status = block_read(buf, 4); + if (status != 0) + return status; + + uint32_t v = buf[3] + ((uint32_t)buf[2] << 8) + ((uint32_t)buf[1] << 16) + ((uint32_t)buf[0] << 24); + return (int64_t)v; +} + +int png_decoder::fetch_next_chunk_data(uint8_t* buf, int bytes) +{ + if (!m_chunk_flag) + return 0; + + bytes = minimum<int>(bytes, m_chunk_left); + + int status = block_read(buf, bytes); + if (status != 0) + return status; + +#if PVPNG_IDAT_CRC_CHECKING + bool check_crc32 = true; +#else + const bool is_idat = (m_chunk_name[0] == 'I') && (m_chunk_name[1] == 'D') && (m_chunk_name[2] == 'A') && (m_chunk_name[3] == 'T'); + bool check_crc32 = !is_idat; +#endif + + if (check_crc32) + m_chunk_crc32 = buminiz::mz_crc32(m_chunk_crc32, buf, bytes); + + if ((m_chunk_left -= bytes) == 0) + { + int64_t res = block_read_dword(); + if (res < 0) + return (int)res; + + if (check_crc32) + { + if (m_chunk_crc32 != (uint32_t)res) + return terminate(PNG_BAD_CHUNK_CRC32); + } + + m_chunk_flag = FALSE; + } + + return bytes; +} + +int png_decoder::fetch_next_chunk_byte() +{ + uint8_t buf[1]; + + int status = fetch_next_chunk_data(buf, 1); + if (status < 0) + return status; + + if (status != 1) + return terminate(PNG_BAD_CHUNK_SIZE); + + return buf[0]; +} + +int png_decoder::fetch_next_chunk_word() +{ + uint8_t buf[2]; + + int status = fetch_next_chunk_data(buf, 2); + if (status < 0) + return status; + + if (status != 2) + return terminate(PNG_BAD_CHUNK_SIZE); + + return buf[1] + ((uint32_t)buf[0] << 8); +} + +int64_t png_decoder::fetch_next_chunk_dword() +{ + uint8_t buf[4]; + + int status = fetch_next_chunk_data(buf, 4); + if (status < 0) + return status; + + if (status != 4) + terminate(PNG_BAD_CHUNK_SIZE); + + uint32_t v = buf[3] + ((uint32_t)buf[2] << 8) + ((uint32_t)buf[1] << 16) + ((uint32_t)buf[0] << 24); + return (int64_t)v; +} + +int png_decoder::fetch_next_chunk_init() +{ + while (m_chunk_flag) + { + int status = fetch_next_chunk_data(m_temp_buf, TEMP_BUF_SIZE * 4); + if (status != 0) + return status; + } + + int64_t n = block_read_dword(); + if (n < 0) + return (int)n; + + m_chunk_size = (uint32_t)n; + + m_chunk_flag = TRUE; + m_chunk_left = m_chunk_size + 4; + m_chunk_crc32 = 0; + + int status = fetch_next_chunk_data(m_chunk_name, 4); + if (status < 0) + return status; + + return 0; +} + +int png_decoder::unchunk_data(uint8_t* buf, uint32_t bytes, uint32_t* ptr_bytes_read) +{ + uint32_t bytes_read = 0; + + if ((!bytes) || (m_end_of_idat_chunks)) + { + *ptr_bytes_read = 0; + return TRUE; + } + + while (bytes_read != bytes) + { + if (!m_chunk_flag) + { + int res = fetch_next_chunk_init(); + if (res < 0) + return res; + + if ((m_chunk_name[0] != 'I') || + (m_chunk_name[1] != 'D') || + (m_chunk_name[2] != 'A') || + (m_chunk_name[3] != 'T')) + { + *ptr_bytes_read = bytes_read; + m_end_of_idat_chunks = TRUE; + return TRUE; + } + } + + int res = fetch_next_chunk_data(buf + bytes_read, bytes - bytes_read); + if (res < 0) + return res; + + bytes_read += (uint32_t)res; + } + + *ptr_bytes_read = bytes_read; + + return FALSE; +} + +inline void png_decoder::adam7_write_pixel_8(int x, int y, int c) +{ + m_adam7_image_buf[x + y * m_dst_bytes_per_line] = (uint8_t)c; +} + +inline void png_decoder::adam7_write_pixel_16(int x, int y, int r, int g) +{ + uint32_t ofs = x * 2 + y * m_dst_bytes_per_line; + m_adam7_image_buf[ofs + 0] = (uint8_t)r; + m_adam7_image_buf[ofs + 1] = (uint8_t)g; +} + +inline void png_decoder::adam7_write_pixel_24(int x, int y, int r, int g, int b) +{ + uint32_t ofs = x * 3 + y * m_dst_bytes_per_line; + m_adam7_image_buf[ofs + 0] = (uint8_t)r; + m_adam7_image_buf[ofs + 1] = (uint8_t)g; + m_adam7_image_buf[ofs + 2] = (uint8_t)b; +} + +inline void png_decoder::adam7_write_pixel_32(int x, int y, int r, int g, int b, int a) +{ + uint32_t ofs = x * 4 + y * m_dst_bytes_per_line; + m_adam7_image_buf[ofs + 0] = (uint8_t)r; + m_adam7_image_buf[ofs + 1] = (uint8_t)g; + m_adam7_image_buf[ofs + 2] = (uint8_t)b; + m_adam7_image_buf[ofs + 3] = (uint8_t)a; +} + +static void PixelDePack2(void* src, void* dst, int numbytes) +{ + uint8_t* src8 = (uint8_t*)src; + uint8_t* dst8 = (uint8_t*)dst; + + while (numbytes) + { + uint8_t v = *src8++; + + for (uint32_t i = 0; i < 8; i++) + dst8[7 - i] = (v >> i) & 1; + + dst8 += 8; + numbytes--; + } +} + +static void PixelDePack16(void* src, void* dst, int numbytes) +{ + uint8_t* src8 = (uint8_t*)src; + uint8_t* dst8 = (uint8_t*)dst; + + while (numbytes) + { + uint8_t v = *src8++; + + dst8[0] = (uint8_t)v >> 4; + dst8[1] = (uint8_t)v & 0xF; + dst8 += 2; + + numbytes--; + } +} + +static int unpack_grey_1(uint8_t* src, uint8_t* dst, int pixels, png_decoder *pwi) +{ + (void)pwi; + PixelDePack2(src, dst, pixels >> 3); + + dst += (pixels & 0xFFF8); + + if ((pixels & 7) != 0) + { + uint8_t c = src[pixels >> 3]; + + pixels &= 7; + + while (pixels--) + { + *dst++ = ((c & 128) >> 7); + + c <<= 1; + } + } + + return TRUE; +} + +static int unpack_grey_2(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)pwi; + int i = pixels; + uint8_t c; + + while (i >= 4) + { + c = *src++; + + *dst++ = (c >> 6); + *dst++ = (c >> 4) & 3; + *dst++ = (c >> 2) & 3; + *dst++ = (c) & 3; + + i -= 4; + } + + if (i) + { + c = *src; + + while (i--) + { + *dst++ = (c >> 6); + + c <<= 2; + } + } + + return TRUE; +} + +static int unpack_grey_4(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)pwi; + + PixelDePack16(src, dst, pixels >> 1); + + if (pixels & 1) + dst[pixels & 0xFFFE] = (src[pixels >> 1] >> 4); + + return TRUE; +} + +static int unpack_grey_8(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)src; + (void)dst; + (void)pixels; + (void)pwi; + return FALSE; +} + +static int unpack_grey_16(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)pwi; + while (pixels--) + { + *dst++ = *src++; + + src++; + } + + return TRUE; +} + +static int unpack_grey_16_2(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + if (pwi->m_trns_flag) + { + while (pixels--) + { + uint32_t v = (src[0] << 8) + src[1]; + src += 2; + + *dst++ = (uint8_t)(v >> 8); + *dst++ = (v == pwi->m_trns_value[0]) ? 0 : 255; + } + } + else + { + while (pixels--) + { + *dst++ = *src++; + *dst++ = 0xFF; + + src++; + } + } + + return TRUE; +} + +static int unpack_true_8(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + if (pwi->m_trns_flag) + { + const uint32_t tr = pwi->m_trns_value[0]; + const uint32_t tg = pwi->m_trns_value[1]; + const uint32_t tb = pwi->m_trns_value[2]; + + for (int i = 0; i < pixels; i++) + { + uint8_t r = src[i * 3 + 0]; + uint8_t g = src[i * 3 + 1]; + uint8_t b = src[i * 3 + 2]; + + dst[i * 4 + 0] = r; + dst[i * 4 + 1] = g; + dst[i * 4 + 2] = b; + dst[i * 4 + 3] = ((r == tr) && (g == tg) && (b == tb)) ? 0 : 255; + } + } + else + { + for (int i = 0; i < pixels; i++) + { + dst[i * 4 + 0] = src[i * 3 + 0]; + dst[i * 4 + 1] = src[i * 3 + 1]; + dst[i * 4 + 2] = src[i * 3 + 2]; + dst[i * 4 + 3] = 255; + } + } + + return TRUE; +} + +static int unpack_true_16(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + if (pwi->m_trns_flag) + { + const uint32_t tr = pwi->m_trns_value[0]; + const uint32_t tg = pwi->m_trns_value[1]; + const uint32_t tb = pwi->m_trns_value[2]; + + for (int i = 0; i < pixels; i++) + { + uint32_t r = (src[i * 6 + 0] << 8) + src[i * 6 + 1]; + uint32_t g = (src[i * 6 + 2] << 8) + src[i * 6 + 3]; + uint32_t b = (src[i * 6 + 4] << 8) + src[i * 6 + 5]; + + dst[i * 4 + 0] = (uint8_t)(r >> 8); + dst[i * 4 + 1] = (uint8_t)(g >> 8); + dst[i * 4 + 2] = (uint8_t)(b >> 8); + dst[i * 4 + 3] = ((r == tr) && (g == tg) && (b == tb)) ? 0 : 255; + } + } + else + { + while (pixels--) + { + dst[0] = src[0]; + dst[1] = src[2]; + dst[2] = src[4]; + dst[3] = 255; + + dst += 4; + src += 6; + } + } + + return TRUE; +} + +static int unpack_grey_alpha_8(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)pwi; + while (pixels--) + { + dst[0] = src[0]; + dst[1] = src[1]; + dst += 2; + src += 2; + } + + return TRUE; +} + +static int unpack_grey_alpha_16(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)pwi; + while (pixels--) + { + dst[0] = src[0]; + dst[1] = src[2]; + dst += 2; + src += 4; + } + + return TRUE; +} + +static int unpack_true_alpha_8(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)src; + (void)dst; + (void)pixels; + (void)pwi; + return FALSE; +} + +static int unpack_true_alpha_16(uint8_t* src, uint8_t* dst, int pixels, png_decoder* pwi) +{ + (void)pwi; + while (pixels--) + { + dst[0] = src[0]; + dst[1] = src[2]; + dst[2] = src[4]; + dst[3] = src[6]; + dst += 4; + src += 8; + } + + return TRUE; +} + +void png_decoder::unpredict_sub(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp) +{ + (void)lst; + if (bytes == (uint32_t)bpp) + return; + + cur += bpp; + bytes -= bpp; + + while (bytes--) + { + *cur += *(cur - bpp); + cur++; + } +} + +void png_decoder::unpredict_up(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp) +{ + (void)bpp; + while (bytes--) + *cur++ += *lst++; +} + +void png_decoder::unpredict_average(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp) +{ + int i; + + for (i = 0; i < bpp; i++) + *cur++ += (*lst++ >> 1); + + if (bytes == (uint32_t)bpp) + return; + + bytes -= bpp; + + while (bytes--) + { + *cur += ((*lst++ + *(cur - bpp)) >> 1); + cur++; + } +} + +inline uint8_t png_decoder::paeth_predictor(int a, int b, int c) +{ + int p, pa, pb, pc; + + /* a = left, b = above, c = upper left */ + + p = a + b - c; + + pa = abs(p - a); + pb = abs(p - b); + pc = abs(p - c); + + if ((pa <= pb) && (pa <= pc)) + return (uint8_t)a; + else if (pb <= pc) + return (uint8_t)b; + else + return (uint8_t)c; +} + +void png_decoder::unpredict_paeth(uint8_t* lst, uint8_t* cur, uint32_t bytes, int bpp) +{ + int i; + + for (i = 0; i < bpp; i++) + *cur++ += paeth_predictor(0, *lst++, 0); + + if (bytes == (uint32_t)bpp) + return; + + bytes -= bpp; + + while (bytes--) + { + int p, a, b, c, pa, pb, pc; + + a = *(cur - bpp); + b = *lst; + c = *(lst - bpp); + + p = a + b - c; + + pa = abs(p - a); + pb = abs(p - b); + pc = abs(p - c); + + if ((pa <= pb) && (pa <= pc)) + *cur++ += (uint8_t)a; + else if (pb <= pc) + *cur++ += (uint8_t)b; + else + *cur++ += (uint8_t)c; + + lst++; + } +} + +int png_decoder::adam7_pass_size(int size, int start, int step) +{ + if (size > start) + return 1 + ((size - 1) - start) / step; + else + return 0; +} + +// TRUE if no more data, negative on error, FALSE if OK +int png_decoder::decompress_line(uint32_t* bytes_decoded) +{ + int status; + uint32_t temp, src_bytes_left, dst_bytes_left; + + m_inflate_dst_buf_ofs = 0; + + for (; ; ) + { + if (m_inflate_src_buf_ofs == PNG_INFLATE_SRC_BUF_SIZE) + { + int res = unchunk_data(inflate_src_buf, PNG_INFLATE_SRC_BUF_SIZE, &temp); + if (res < 0) + return res; + m_inflate_eof_flag = res; + + m_inflate_src_buf_size = temp; + + m_inflate_src_buf_ofs = 0; + } + + for (; ; ) + { + src_bytes_left = m_inflate_src_buf_size - m_inflate_src_buf_ofs; + dst_bytes_left = m_dec_bytes_per_line - m_inflate_dst_buf_ofs; + + m_inflator.next_in = inflate_src_buf + m_inflate_src_buf_ofs; + m_inflator.avail_in = src_bytes_left; + + m_inflator.next_out = m_pCur_line_buf + m_inflate_dst_buf_ofs; + m_inflator.avail_out = dst_bytes_left; + + status = buminiz::mz_inflate2(&m_inflator, buminiz::MZ_NO_FLUSH, PVPNG_ADLER32_CHECKING); + + const uint32_t src_bytes_consumed = src_bytes_left - m_inflator.avail_in; + const uint32_t dst_bytes_written = dst_bytes_left - m_inflator.avail_out; + + m_inflate_src_buf_ofs += src_bytes_consumed; + m_inflate_dst_buf_ofs += dst_bytes_written; + + if (status != buminiz::MZ_OK) + { + if (status != buminiz::MZ_STREAM_END) + return terminate(PNG_INVALID_DATA_STREAM); + + if (bytes_decoded) + *bytes_decoded = m_inflate_dst_buf_ofs; + + return TRUE; + } + + if (m_inflate_dst_buf_ofs == m_dec_bytes_per_line) + { + if (bytes_decoded) + *bytes_decoded = m_inflate_dst_buf_ofs; + + return FALSE; + } + + if ((m_inflate_src_buf_ofs == m_inflate_src_buf_size) && + (m_inflate_eof_flag == FALSE)) + break; + } + } +} + +int png_decoder::find_iend_chunk() +{ + uint32_t dummy; + + while (!m_end_of_idat_chunks) + { + int res = unchunk_data(m_temp_buf, TEMP_BUF_SIZE * 4, &dummy); + if (res < 0) + return res; + } + + for (; ; ) + { + if ((m_chunk_name[0] == 'I') && + (m_chunk_name[1] == 'E') && + (m_chunk_name[2] == 'N') && + (m_chunk_name[3] == 'D')) + break; + + int res = fetch_next_chunk_init(); + if (res < 0) + return res; + } + + return 0; +} + +int png_decoder::png_decode(void** ppImg_ptr, uint32_t* pImg_len) +{ + int status; + uint8_t* decoded_line; + uint32_t bytes_decoded; + + if (m_adam7_decoded_flag) + { + if (m_pass_y_left == 0) + return PNG_ALLDONE; + + *ppImg_ptr = &m_adam7_image_buf[(m_ihdr.m_height - m_pass_y_left) * m_dst_bytes_per_line]; + *pImg_len = m_dst_bytes_per_line; + + m_pass_y_left--; + + return 0; + } + + if (m_pass_y_left == 0) + { + if (m_ihdr.m_ilace_type == 0) + { + status = find_iend_chunk(); + if (status < 0) + return status; + + return PNG_ALLDONE; + } + + for (; ; ) + { + if (++m_adam7_pass_num == 7) + { + status = find_iend_chunk(); + if (status < 0) + return status; + + return PNG_ALLDONE; + } + + if (((m_pass_y_left = m_adam7_pass_size_y[m_adam7_pass_num]) != 0) && + ((m_pass_x_size = m_adam7_pass_size_x[m_adam7_pass_num]) != 0)) + break; + } + + switch (m_adam7_pass_num) + { + case 0: + case 1: + case 3: + case 5: + m_adam7_pass_y = 0; + break; + case 2: + m_adam7_pass_y = 4; + break; + case 4: + m_adam7_pass_y = 2; + break; + case 6: + m_adam7_pass_y = 1; + break; + } + + switch (m_ihdr.m_color_type) + { + case PNG_COLOR_TYPE_GREYSCALE: + case PNG_COLOR_TYPE_PALETTIZED: + { + m_src_bytes_per_line = (((uint32_t)m_pass_x_size * m_ihdr.m_bit_depth) + 7) / 8; + break; + } + case PNG_COLOR_TYPE_TRUECOLOR: + { + m_src_bytes_per_line = ((uint32_t)m_pass_x_size * m_dec_bytes_per_pixel); + break; + } + case PNG_COLOR_TYPE_GREYSCALE_ALPHA: + { + m_src_bytes_per_line = ((uint32_t)m_pass_x_size * m_dec_bytes_per_pixel); + break; + } + case PNG_COLOR_TYPE_TRUECOLOR_ALPHA: + { + m_src_bytes_per_line = ((uint32_t)m_pass_x_size * m_dec_bytes_per_pixel); + break; + } + } + + m_dec_bytes_per_line = m_src_bytes_per_line + 1; + + memset(m_pPre_line_buf, 0, m_src_bytes_per_line); + } + + int res = decompress_line(&bytes_decoded); + if (res < 0) + return terminate(res); + + if (res) + { + if (m_ihdr.m_ilace_type == 0) + { + if (m_pass_y_left != 1) + return terminate(PNG_INCOMPLETE_IMAGE); + } + else + { + if ((m_pass_y_left != 1) && (m_adam7_pass_num != 6)) + return terminate(PNG_INCOMPLETE_IMAGE); + } + } + + if (bytes_decoded != m_dec_bytes_per_line) + return terminate(PNG_INCOMPLETE_IMAGE); + + decoded_line = &m_pCur_line_buf[1]; + + switch (m_pCur_line_buf[0]) + { + case 0: + break; + case 1: + { + unpredict_sub(m_pPre_line_buf, m_pCur_line_buf + 1, m_src_bytes_per_line, m_dec_bytes_per_pixel); + break; + } + case 2: + { + unpredict_up(m_pPre_line_buf, m_pCur_line_buf + 1, m_src_bytes_per_line, m_dec_bytes_per_pixel); + break; + } + case 3: + { + unpredict_average(m_pPre_line_buf, m_pCur_line_buf + 1, m_src_bytes_per_line, m_dec_bytes_per_pixel); + break; + } + case 4: + { + unpredict_paeth(m_pPre_line_buf, m_pCur_line_buf + 1, m_src_bytes_per_line, m_dec_bytes_per_pixel); + break; + } + default: + return terminate(PNG_UNS_PREDICTOR); + } + + memmove(m_pPre_line_buf, m_pCur_line_buf + 1, m_src_bytes_per_line); + + if (m_pProcess_func) + { + if ((*m_pProcess_func)(m_pCur_line_buf + 1, m_pPro_line_buf, m_pass_x_size, this)) + decoded_line = m_pPro_line_buf; + } + + if (m_ihdr.m_ilace_type == 0) + { + *ppImg_ptr = decoded_line; + *pImg_len = m_dst_bytes_per_line; + + if (--m_pass_y_left == 0) + { + res = decompress_line(&bytes_decoded); + if (res < 0) + return terminate(res); + + if (res == FALSE) + return terminate(PNG_TOO_MUCH_DATA); + + if (bytes_decoded) + return terminate(PNG_TOO_MUCH_DATA); + } + } + else + { + int i, x_ofs = 0, y_ofs = 0, x_stp = 0; + uint8_t* p = decoded_line; + + switch (m_adam7_pass_num) + { + case 0: { x_ofs = 0; x_stp = 8; break; } + case 1: { x_ofs = 4; x_stp = 8; break; } + case 2: { x_ofs = 0; x_stp = 4; break; } + case 3: { x_ofs = 2; x_stp = 4; break; } + case 4: { x_ofs = 0; x_stp = 2; break; } + case 5: { x_ofs = 1; x_stp = 2; break; } + case 6: { x_ofs = 0; x_stp = 1; break; } + } + + y_ofs = m_adam7_pass_y; + + assert(x_ofs < (int)m_ihdr.m_width); + assert(y_ofs < (int)m_ihdr.m_height); + + if (m_dst_bytes_per_pixel == 1) + { + for (i = m_pass_x_size; i > 0; i--, x_ofs += x_stp) + adam7_write_pixel_8(x_ofs, y_ofs, *p++); + } + else if (m_dst_bytes_per_pixel == 2) + { + for (i = m_pass_x_size; i > 0; i--, x_ofs += x_stp, p += 2) + adam7_write_pixel_16(x_ofs, y_ofs, p[0], p[1]); + } + else if (m_dst_bytes_per_pixel == 3) + { + for (i = m_pass_x_size; i > 0; i--, x_ofs += x_stp, p += 3) + adam7_write_pixel_24(x_ofs, y_ofs, p[0], p[1], p[2]); + } + else if (m_dst_bytes_per_pixel == 4) + { + for (i = m_pass_x_size; i > 0; i--, x_ofs += x_stp, p += 4) + adam7_write_pixel_32(x_ofs, y_ofs, p[0], p[1], p[2], p[3]); + } + else + { + assert(0); + } + + switch (m_adam7_pass_num) + { + case 0: + case 1: + case 2: { m_adam7_pass_y += 8; break; } + case 3: + case 4: { m_adam7_pass_y += 4; break; } + case 5: + case 6: { m_adam7_pass_y += 2; break; } + } + + if ((--m_pass_y_left == 0) && (m_adam7_pass_num == 6)) + { + res = decompress_line(&bytes_decoded); + if (res < 0) + return terminate(res); + + if (res == FALSE) + return terminate(PNG_TOO_MUCH_DATA); + + if (bytes_decoded) + return terminate(PNG_TOO_MUCH_DATA); + } + } + + return 0; +} + +void png_decoder::png_decode_end() +{ + uninitialize(); +} + +int png_decoder::png_decode_start() +{ + int status; + + if (m_img_supported_flag != TRUE) + return terminate(m_img_supported_flag); + + switch (m_ihdr.m_color_type) + { + case PNG_COLOR_TYPE_GREYSCALE: + { + if (m_ihdr.m_bit_depth == 16) + { + // This is a special case. We can't pass back 8-bit samples and let the caller decide on transparency because the PNG is 16-bits. + // So we expand to 8-bit Gray-Alpha and handle transparency during decoding. + // We don't do this with all grayscale cases because that would require more code to deal with 1/2/4bpp expansion. + m_dec_bytes_per_pixel = (m_ihdr.m_bit_depth + 7) / 8; + m_dst_bytes_per_pixel = 2; + + m_src_bytes_per_line = (((uint32_t)m_ihdr.m_width * m_ihdr.m_bit_depth) + 7) / 8; + m_dst_bytes_per_line = 2 * m_ihdr.m_width; + + m_pProcess_func = unpack_grey_16_2; + } + else + { + m_dec_bytes_per_pixel = (m_ihdr.m_bit_depth + 7) / 8; + m_dst_bytes_per_pixel = 1; + + m_src_bytes_per_line = (((uint32_t)m_ihdr.m_width * m_ihdr.m_bit_depth) + 7) / 8; + m_dst_bytes_per_line = m_ihdr.m_width; + + if (m_ihdr.m_bit_depth == 1) + m_pProcess_func = unpack_grey_1; + else if (m_ihdr.m_bit_depth == 2) + m_pProcess_func = unpack_grey_2; + else if (m_ihdr.m_bit_depth == 4) + m_pProcess_func = unpack_grey_4; + else + m_pProcess_func = unpack_grey_8; + } + + break; + } + case PNG_COLOR_TYPE_PALETTIZED: + { + m_dec_bytes_per_pixel = (m_ihdr.m_bit_depth + 7) / 8; + m_dst_bytes_per_pixel = 1; + + m_src_bytes_per_line = (((uint32_t)m_ihdr.m_width * m_ihdr.m_bit_depth) + 7) / 8; + m_dst_bytes_per_line = m_ihdr.m_width; + + if (m_ihdr.m_bit_depth == 1) + m_pProcess_func = unpack_grey_1; + else if (m_ihdr.m_bit_depth == 2) + m_pProcess_func = unpack_grey_2; + else if (m_ihdr.m_bit_depth == 4) + m_pProcess_func = unpack_grey_4; + else if (m_ihdr.m_bit_depth == 8) + m_pProcess_func = unpack_grey_8; + else if (m_ihdr.m_bit_depth == 16) + m_pProcess_func = unpack_grey_16; + + break; + } + case PNG_COLOR_TYPE_TRUECOLOR: + { + // We always pass back alpha with transparency handling. + m_dec_bytes_per_pixel = 3 * (m_ihdr.m_bit_depth / 8); + m_dst_bytes_per_pixel = 4; + + m_src_bytes_per_line = ((uint32_t)m_ihdr.m_width * m_dec_bytes_per_pixel); + m_dst_bytes_per_line = 4 * m_ihdr.m_width; + + if (m_ihdr.m_bit_depth == 8) + m_pProcess_func = unpack_true_8; + else if (m_ihdr.m_bit_depth == 16) + m_pProcess_func = unpack_true_16; + + break; + } + case PNG_COLOR_TYPE_GREYSCALE_ALPHA: + { + m_dec_bytes_per_pixel = 2 * (m_ihdr.m_bit_depth / 8); + m_dst_bytes_per_pixel = 2; + + m_src_bytes_per_line = ((uint32_t)m_ihdr.m_width * m_dec_bytes_per_pixel); + m_dst_bytes_per_line = m_ihdr.m_width * 2; + + if (m_ihdr.m_bit_depth == 8) + m_pProcess_func = unpack_grey_alpha_8; + else if (m_ihdr.m_bit_depth == 16) + m_pProcess_func = unpack_grey_alpha_16; + + break; + } + case PNG_COLOR_TYPE_TRUECOLOR_ALPHA: + { + m_dec_bytes_per_pixel = 4 * (m_ihdr.m_bit_depth / 8); + m_dst_bytes_per_pixel = 4; + + m_src_bytes_per_line = ((uint32_t)m_ihdr.m_width * m_dec_bytes_per_pixel); + m_dst_bytes_per_line = 4 * m_ihdr.m_width; + + if (m_ihdr.m_bit_depth == 8) + m_pProcess_func = unpack_true_alpha_8; + else + m_pProcess_func = unpack_true_alpha_16; + + break; + } + } + + m_dec_bytes_per_line = m_src_bytes_per_line + 1; + + m_pPre_line_buf = (uint8_t*)png_calloc(m_src_bytes_per_line); + m_pCur_line_buf = (uint8_t*)png_calloc(m_dec_bytes_per_line); + m_pPro_line_buf = (uint8_t*)png_calloc(m_dst_bytes_per_line); + + if (!m_pPre_line_buf || !m_pCur_line_buf || !m_pPro_line_buf) + return terminate(PNG_NOTENOUGHMEM); + + m_inflate_src_buf_ofs = PNG_INFLATE_SRC_BUF_SIZE; + + int res = mz_inflateInit(&m_inflator); + if (res != 0) + return terminate(PNG_DECERROR); + + if (m_ihdr.m_ilace_type == 1) + { + int i; + uint32_t total_lines, lines_processed; + + m_adam7_pass_size_x[0] = adam7_pass_size(m_ihdr.m_width, 0, 8); + m_adam7_pass_size_x[1] = adam7_pass_size(m_ihdr.m_width, 4, 8); + m_adam7_pass_size_x[2] = adam7_pass_size(m_ihdr.m_width, 0, 4); + m_adam7_pass_size_x[3] = adam7_pass_size(m_ihdr.m_width, 2, 4); + m_adam7_pass_size_x[4] = adam7_pass_size(m_ihdr.m_width, 0, 2); + m_adam7_pass_size_x[5] = adam7_pass_size(m_ihdr.m_width, 1, 2); + m_adam7_pass_size_x[6] = adam7_pass_size(m_ihdr.m_width, 0, 1); + + m_adam7_pass_size_y[0] = adam7_pass_size(m_ihdr.m_height, 0, 8); + m_adam7_pass_size_y[1] = adam7_pass_size(m_ihdr.m_height, 0, 8); + m_adam7_pass_size_y[2] = adam7_pass_size(m_ihdr.m_height, 4, 8); + m_adam7_pass_size_y[3] = adam7_pass_size(m_ihdr.m_height, 0, 4); + m_adam7_pass_size_y[4] = adam7_pass_size(m_ihdr.m_height, 2, 4); + m_adam7_pass_size_y[5] = adam7_pass_size(m_ihdr.m_height, 0, 2); + m_adam7_pass_size_y[6] = adam7_pass_size(m_ihdr.m_height, 1, 2); + + m_adam7_image_buf.resize(m_dst_bytes_per_line * m_ihdr.m_height); + + m_adam7_pass_num = -1; + + m_pass_y_left = 0; + + total_lines = lines_processed = 0; + + for (i = 0; i < 7; i++) + total_lines += m_adam7_pass_size_y[i]; + + for (; ; ) + { + void* dummy_ptr = nullptr; + uint32_t dummy_len = 0; + + status = png_decode(&dummy_ptr, &dummy_len); + + if (status) + { + if (status == PNG_ALLDONE) + break; + else + { + uninitialize(); + + return status; + } + } + + lines_processed++; + } + + m_adam7_decoded_flag = TRUE; + m_pass_y_left = m_ihdr.m_height; + } + else + { + m_pass_x_size = m_ihdr.m_width; + m_pass_y_left = m_ihdr.m_height; + } + + return 0; +} + +void png_decoder::calc_gamma_table() +{ + if (m_gama_value == 45000) + { + for (int i = 0; i < 256; i++) + m_gamma_table[i] = (uint8_t)i; + return; + } + + float gamma = (float)(m_gama_value) / 100000.0f; + + gamma = 1.0f / (gamma * 2.2f); + + for (int i = 0; i < 256; i++) + { + float temp = powf((float)(i) / 255.0f, gamma) * 255.0f; + + int j = (int)(temp + .5f); + + if (j < 0) + j = 0; + else if (j > 255) + j = 255; + + m_gamma_table[i] = (uint8_t)j; + } +} + +void png_decoder::create_grey_palette() +{ + int i, j; + uint8_t* p = m_img_pal; + + const int img_colors = minimum(256, 1 << m_ihdr.m_bit_depth); + for (i = 0; i < img_colors; i++) + { + j = ((uint32_t)255 * (uint32_t)i) / (img_colors - 1); + + *p++ = (uint8_t)j; + *p++ = (uint8_t)j; + *p++ = (uint8_t)j; + } +} + +int png_decoder::read_signature() +{ + if (m_pFile->read(m_temp_buf, 8) != 8) + return terminate(PNG_UNKNOWNTYPE); + + if ((m_temp_buf[0] != 137) || + (m_temp_buf[1] != 80) || + (m_temp_buf[2] != 78) || + (m_temp_buf[3] != 71) || + (m_temp_buf[4] != 13) || + (m_temp_buf[5] != 10) || + (m_temp_buf[6] != 26) || + (m_temp_buf[7] != 10)) + { + return terminate(PNG_UNKNOWNTYPE); + } + + return 0; +} + +int png_decoder::read_ihdr_chunk() +{ + int res = fetch_next_chunk_init(); + if (res < 0) + return res; + + if ((m_chunk_name[0] != 'I') || (m_chunk_name[1] != 'H') || (m_chunk_name[2] != 'D') || (m_chunk_name[3] != 'R') || (m_chunk_size != 13)) + return terminate(PNG_NO_IHDR); + + int64_t v64 = fetch_next_chunk_dword(); + if (v64 < 0) + return (int)v64; + m_ihdr.m_width = (uint32_t)v64; + + v64 = fetch_next_chunk_dword(); + if (v64 < 0) + return (int)v64; + m_ihdr.m_height = (uint32_t)v64; + + if ((m_ihdr.m_width == 0) || (m_ihdr.m_width > MAX_SUPPORTED_RES)) + return terminate(PNG_BAD_WIDTH); + + if ((m_ihdr.m_height == 0) || (m_ihdr.m_height > MAX_SUPPORTED_RES)) + return terminate(PNG_BAD_HEIGHT); + + int v = fetch_next_chunk_byte(); + if (v < 0) + return v; + m_ihdr.m_bit_depth = (uint8_t)v; + + v = fetch_next_chunk_byte(); + if (v < 0) + return v; + m_ihdr.m_color_type = (uint8_t)v; + + v = fetch_next_chunk_byte(); + if (v < 0) + return v; + m_ihdr.m_comp_type = (uint8_t)v; + + v = fetch_next_chunk_byte(); + if (v < 0) + return v; + m_ihdr.m_filter_type = (uint8_t)v; + + v = fetch_next_chunk_byte(); + if (v < 0) + return v; + m_ihdr.m_ilace_type = (uint8_t)v; + + if (m_ihdr.m_comp_type != 0) + m_img_supported_flag = PNG_UNS_COMPRESSION; + + if (m_ihdr.m_filter_type != 0) + m_img_supported_flag = PNG_UNS_FILTER; + + if (m_ihdr.m_ilace_type > 1) + m_img_supported_flag = PNG_UNS_ILACE; + + switch (m_ihdr.m_color_type) + { + case PNG_COLOR_TYPE_GREYSCALE: + { + switch (m_ihdr.m_bit_depth) + { + case 1: + case 2: + case 4: + case 8: + case 16: + { + break; + } + default: + return terminate(PNG_BAD_BIT_DEPTH); + } + + break; + } + case PNG_COLOR_TYPE_PALETTIZED: + { + switch (m_ihdr.m_bit_depth) + { + case 1: + case 2: + case 4: + case 8: + { + break; + } + default: + return terminate(PNG_BAD_BIT_DEPTH); + } + + break; + } + case PNG_COLOR_TYPE_TRUECOLOR: + case PNG_COLOR_TYPE_GREYSCALE_ALPHA: + case PNG_COLOR_TYPE_TRUECOLOR_ALPHA: + { + switch (m_ihdr.m_bit_depth) + { + case 8: + case 16: + { + break; + } + default: + return terminate(PNG_BAD_BIT_DEPTH); + } + + break; + } + default: + return terminate(PNG_UNS_COLOR_TYPE); + } + + return 0; +} + +int png_decoder::read_bkgd_chunk() +{ + m_bkgd_flag = TRUE; + + if (m_ihdr.m_color_type == PNG_COLOR_TYPE_PALETTIZED) + { + int v = fetch_next_chunk_byte(); + if (v < 0) + return v; + m_bkgd_value[0] = v; + } + else if ((m_ihdr.m_color_type == PNG_COLOR_TYPE_GREYSCALE) || (m_ihdr.m_color_type == PNG_COLOR_TYPE_GREYSCALE_ALPHA)) + { + int v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_bkgd_value[0] = v; + } + else if ((m_ihdr.m_color_type == PNG_COLOR_TYPE_TRUECOLOR) || (m_ihdr.m_color_type == PNG_COLOR_TYPE_TRUECOLOR_ALPHA)) + { + int v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_bkgd_value[0] = v; + + v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_bkgd_value[1] = v; + + v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_bkgd_value[2] = v; + } + + return 0; +} + +int png_decoder::read_gama_chunk() +{ + m_gama_flag = TRUE; + + int64_t v = fetch_next_chunk_dword(); + if (v < 0) + return (int)v; + + m_gama_value = (uint32_t)v; + + return 0; +} + +int png_decoder::read_trns_chunk() +{ + int i; + + m_trns_flag = TRUE; + + if (m_ihdr.m_color_type == PNG_COLOR_TYPE_PALETTIZED) + { + for (i = 0; i < 256; i++) + m_trns_value[i] = 255; + + const uint32_t img_colors = 1 << m_ihdr.m_bit_depth; + if (m_chunk_size > (uint32_t)img_colors) + return terminate(PNG_BAD_TRNS_CHUNK); + + for (i = 0; i < (int)m_chunk_size; i++) + { + int v = fetch_next_chunk_byte(); + if (v < 0) + return v; + m_trns_value[i] = v; + } + } + else if (m_ihdr.m_color_type == PNG_COLOR_TYPE_GREYSCALE) + { + int v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_trns_value[0] = v; + } + else if (m_ihdr.m_color_type == PNG_COLOR_TYPE_TRUECOLOR) + { + int v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_trns_value[0] = v; + + v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_trns_value[1] = v; + + v = fetch_next_chunk_word(); + if (v < 0) + return v; + m_trns_value[2] = v; + } + else + { + return terminate(PNG_BAD_TRNS_CHUNK); + } + return 0; +} + +int png_decoder::read_plte_chunk() +{ + int i, j; + uint8_t* p; + + if (m_plte_flag) + return terminate(PNG_BAD_PLTE_CHUNK); + + m_plte_flag = TRUE; + + memset(m_img_pal, 0, 768); + + if (m_chunk_size % 3) + return terminate(PNG_BAD_PLTE_CHUNK); + + j = m_chunk_size / 3; + + const int img_colors = minimum(256, 1 << m_ihdr.m_bit_depth); + if (j > img_colors) + return terminate(PNG_BAD_PLTE_CHUNK); + + if ((m_ihdr.m_color_type == PNG_COLOR_TYPE_GREYSCALE) || + (m_ihdr.m_color_type == PNG_COLOR_TYPE_GREYSCALE_ALPHA)) + return terminate(PNG_BAD_PLTE_CHUNK); + + p = m_img_pal; + + for (i = 0; i < j; i++) + { + int v = fetch_next_chunk_byte(); + if (v < 0) + return v; + *p++ = (uint8_t)v; + + v = fetch_next_chunk_byte(); + if (v < 0) + return v; + *p++ = (uint8_t)v; + + v = fetch_next_chunk_byte(); + if (v < 0) + return v; + *p++ = (uint8_t)v; + } + + return 0; +} + +int png_decoder::find_idat_chunk() +{ + for (; ; ) + { + int res = fetch_next_chunk_init(); + if (res < 0) + return res; + + if (m_chunk_name[0] & 32) /* ancillary? */ + { + if ((m_chunk_name[0] == 'b') && (m_chunk_name[1] == 'K') && (m_chunk_name[2] == 'G') && (m_chunk_name[3] == 'D')) + { + res = read_bkgd_chunk(); + if (res < 0) + return res; + } + else if ((m_chunk_name[0] == 'g') && (m_chunk_name[1] == 'A') && (m_chunk_name[2] == 'M') && (m_chunk_name[3] == 'A')) + { + res = read_gama_chunk(); + if (res < 0) + return res; + } + else if ((m_chunk_name[0] == 't') && (m_chunk_name[1] == 'R') && (m_chunk_name[2] == 'N') && (m_chunk_name[3] == 'S')) + { + res = read_trns_chunk(); + if (res < 0) + return res; + } + } + else + { + if ((m_chunk_name[0] == 'P') && (m_chunk_name[1] == 'L') && (m_chunk_name[2] == 'T') && (m_chunk_name[3] == 'E')) + { + res = read_plte_chunk(); + if (res < 0) + return res; + } + else if ((m_chunk_name[0] == 'I') && (m_chunk_name[1] == 'D') && (m_chunk_name[2] == 'A') && (m_chunk_name[3] == 'T')) + { + break; + } + else + { + m_img_supported_flag = PNG_UNS_CRITICAL_CHUNK; + } + } + } + + return 0; +} + +png_decoder::png_decoder() +{ + clear(); +} + +png_decoder::~png_decoder() +{ + uninitialize(); +} + +void png_decoder::clear() +{ + clear_obj(m_pMalloc_blocks); + + m_pFile = nullptr; + + clear_obj(m_img_pal); + + m_img_supported_flag = FALSE; + + m_adam7_image_buf.clear(); + + clear_obj(m_ihdr); + + m_chunk_flag = FALSE; + m_chunk_size = 0; + m_chunk_left = 0; + m_chunk_crc32 = 0; + clear_obj(m_chunk_name); + + m_end_of_idat_chunks = 0; + + m_dec_bytes_per_pixel = 0; + m_dst_bytes_per_pixel = 0; + + m_dec_bytes_per_line = 0; + m_src_bytes_per_line = 0; + m_dst_bytes_per_line = 0; + + m_pProcess_func = nullptr; + + m_pPre_line_buf = nullptr; + m_pCur_line_buf = nullptr; + m_pPro_line_buf = nullptr; + + m_bkgd_flag = FALSE; + clear_obj(m_bkgd_value); + + m_gama_flag = FALSE; + m_gama_value = 0; + + m_plte_flag = FALSE; + + m_trns_flag = FALSE; + clear_obj(m_trns_value); + + clear_obj(m_inflator); + + m_inflate_src_buf_ofs = 0; + m_inflate_src_buf_size = 0; + m_inflate_dst_buf_ofs = 0; + + m_inflate_eof_flag = FALSE; + + clear_obj(m_trns_value); + + m_pass_x_size = 0; + m_pass_y_left = 0; + + m_adam7_pass_num = 0; + m_adam7_pass_y = 0; + clear_obj(m_adam7_pass_size_x); + clear_obj(m_adam7_pass_size_y); + + m_adam7_decoded_flag = FALSE; + + m_scanned_flag = false; + + m_terminate_status = 0; +} + +int png_decoder::png_scan(png_file *pFile) +{ + m_pFile = pFile; + + m_img_supported_flag = TRUE; + m_terminate_status = 0; + + int res = read_signature(); + if (res != 0) + return res; + + res = read_ihdr_chunk(); + if (res != 0) + return res; + + res = find_idat_chunk(); + if (res != 0) + return res; + + if (m_gama_flag) + calc_gamma_table(); + + if (m_ihdr.m_color_type == PNG_COLOR_TYPE_PALETTIZED) + { + if (!m_plte_flag) + return terminate(PNG_MISSING_PALETTE); + } + else if ((m_ihdr.m_color_type == PNG_COLOR_TYPE_GREYSCALE) || (m_ihdr.m_color_type == PNG_COLOR_TYPE_GREYSCALE_ALPHA)) + { + create_grey_palette(); + } + + m_scanned_flag = true; + + return 0; +} + +static inline uint8_t get_709_luma(uint32_t r, uint32_t g, uint32_t b) +{ + return (uint8_t)((13938U * r + 46869U * g + 4729U * b + 32768U) >> 16U); +} + +bool get_png_info(const void* pImage_buf, size_t buf_size, png_info &info) +{ + memset(&info, 0, sizeof(info)); + + if ((!pImage_buf) || (buf_size < MIN_PNG_SIZE)) + return false; + + png_readonly_memory_file mf; + mf.init(pImage_buf, buf_size); + + png_decoder dec; + + int status = dec.png_scan(&mf); + if ((status != 0) || (dec.m_img_supported_flag != TRUE)) + return false; + + info.m_width = dec.m_ihdr.m_width; + info.m_height = dec.m_ihdr.m_height; + info.m_bit_depth = dec.m_ihdr.m_bit_depth; + info.m_color_type = dec.m_ihdr.m_color_type; + info.m_has_gamma = dec.m_gama_flag != 0; + info.m_gamma_value = dec.m_gama_value; + info.m_has_trns = dec.m_trns_flag != 0; + + switch (dec.m_ihdr.m_color_type) + { + case PNG_COLOR_TYPE_GREYSCALE: + info.m_num_chans = dec.m_trns_flag ? 2 : 1; + break; + case PNG_COLOR_TYPE_GREYSCALE_ALPHA: + info.m_num_chans = 2; + break; + case PNG_COLOR_TYPE_PALETTIZED: + case PNG_COLOR_TYPE_TRUECOLOR: + info.m_num_chans = dec.m_trns_flag ? 4 : 3; + break; + case PNG_COLOR_TYPE_TRUECOLOR_ALPHA: + info.m_num_chans = 4; + break; + default: + assert(0); + break; + } + + return true; +} + +void* load_png(const void* pImage_buf, size_t buf_size, uint32_t desired_chans, uint32_t& width, uint32_t& height, uint32_t& num_chans) +{ + width = 0; + height = 0; + num_chans = 0; + + if ((!pImage_buf) || (buf_size < MIN_PNG_SIZE)) + { + assert(0); + return nullptr; + } + + if (desired_chans > 4) + { + assert(0); + return nullptr; + } + + png_readonly_memory_file mf; + mf.init(pImage_buf, buf_size); + + png_decoder dec; + + int status = dec.png_scan(&mf); + if ((status != 0) || (dec.m_img_supported_flag != TRUE)) + return nullptr; + + uint32_t colortype = dec.m_ihdr.m_color_type; + switch (colortype) + { + case PNG_COLOR_TYPE_GREYSCALE: + num_chans = dec.m_trns_flag ? 2 : 1; + break; + case PNG_COLOR_TYPE_GREYSCALE_ALPHA: + num_chans = 2; + break; + case PNG_COLOR_TYPE_PALETTIZED: + case PNG_COLOR_TYPE_TRUECOLOR: + num_chans = dec.m_trns_flag ? 4 : 3; + break; + case PNG_COLOR_TYPE_TRUECOLOR_ALPHA: + num_chans = 4; + break; + default: + assert(0); + break; + } + + if (!desired_chans) + desired_chans = num_chans; + +#if 0 + printf("lode_png: %ux%u bitdepth: %u colortype: %u trns: %u ilace: %u\n", + dec.m_ihdr.m_width, + dec.m_ihdr.m_height, + dec.m_ihdr.m_bit_depth, + dec.m_ihdr.m_color_type, + dec.m_trns_flag, + dec.m_ihdr.m_ilace_type); +#endif + + width = dec.m_ihdr.m_width; + height = dec.m_ihdr.m_height; + uint32_t bitdepth = dec.m_ihdr.m_bit_depth; + uint32_t pitch = width * desired_chans; + + uint64_t total_size = (uint64_t)pitch * height; + if (total_size > 0x7FFFFFFFULL) + return nullptr; + + uint8_t* pBuf = (uint8_t*)malloc((size_t)total_size); + if (!pBuf) + return nullptr; + + if (dec.png_decode_start() != 0) + { + free(pBuf); + return nullptr; + } + + uint8_t* pDst = pBuf; + + for (uint32_t y = 0; y < height; y++, pDst += pitch) + { + uint8_t* pLine; + uint32_t line_bytes; + if (dec.png_decode((void**)&pLine, &line_bytes) != 0) + { + free(pBuf); + return nullptr; + } + + // This conversion matrix handles converting RGB->Luma, converting grayscale samples to 8-bit samples, converting palettized images, and PNG transparency. + switch (colortype) + { + case PNG_COLOR_TYPE_GREYSCALE: + { + uint32_t trans_value = dec.m_trns_value[0]; + + switch (desired_chans) + { + case 1: + if (bitdepth == 16) + { + assert(line_bytes == width * 2); + + for (uint32_t i = 0; i < width; i++) + pDst[i] = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + } + else if (bitdepth == 8) + { + assert(line_bytes == width); + memcpy(pDst, pLine, pitch); + } + else + { + assert(line_bytes == width); + for (uint32_t i = 0; i < width; i++) + pDst[i] = dec.m_img_pal[pLine[i] * 3]; + } + break; + case 2: + if (bitdepth == 16) + { + assert(line_bytes == width * 2); + for (uint32_t i = 0; i < width; i++) + { + pDst[i * 2 + 0] = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + pDst[i * 2 + 1] = pLine[i * 2 + 1]; + } + } + else if (dec.m_trns_flag) + { + assert(line_bytes == width); + for (uint32_t i = 0; i < width; i++) + { + pDst[i * 2 + 0] = dec.m_img_pal[pLine[i] * 3]; + pDst[i * 2 + 1] = (pLine[i] == trans_value) ? 0 : 255; + } + } + else + { + assert(line_bytes == width); + for (uint32_t i = 0; i < width; i++) + { + pDst[i * 2 + 0] = dec.m_img_pal[pLine[i] * 3]; + pDst[i * 2 + 1] = 255; + } + } + break; + case 3: + if (bitdepth == 16) + { + assert(line_bytes == width * 2); + for (uint32_t i = 0; i < width; i++) + { + uint8_t c = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + pDst[i * 3 + 0] = c; + pDst[i * 3 + 1] = c; + pDst[i * 3 + 2] = c; + } + } + else + { + assert(line_bytes == width); + for (uint32_t i = 0; i < width; i++) + { + uint8_t c = dec.m_img_pal[pLine[i] * 3]; + pDst[i * 3 + 0] = c; + pDst[i * 3 + 1] = c; + pDst[i * 3 + 2] = c; + } + } + break; + case 4: + if (bitdepth == 16) + { + assert(line_bytes == width * 2); + for (uint32_t i = 0; i < width; i++) + { + uint8_t c = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + pDst[i * 4 + 0] = c; + pDst[i * 4 + 1] = c; + pDst[i * 4 + 2] = c; + pDst[i * 4 + 3] = pLine[i * 2 + 1]; + } + } + else if (dec.m_trns_flag) + { + assert(line_bytes == width); + for (uint32_t i = 0; i < width; i++) + { + uint8_t c = dec.m_img_pal[pLine[i] * 3]; + pDst[i * 4 + 0] = c; + pDst[i * 4 + 1] = c; + pDst[i * 4 + 2] = c; + pDst[i * 4 + 3] = (pLine[i] == trans_value) ? 0 : 255; + } + } + else + { + assert(line_bytes == width); + for (uint32_t i = 0; i < width; i++) + { + uint8_t c = dec.m_img_pal[pLine[i] * 3]; + pDst[i * 4 + 0] = c; + pDst[i * 4 + 1] = c; + pDst[i * 4 + 2] = c; + pDst[i * 4 + 3] = 255; + } + } + break; + } + + break; + } + case PNG_COLOR_TYPE_GREYSCALE_ALPHA: + { + assert(line_bytes == width * 2); + + switch (desired_chans) + { + case 1: + for (uint32_t i = 0; i < width; i++) + pDst[i] = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + break; + case 2: + assert(line_bytes == pitch); + if (bitdepth >= 8) + memcpy(pDst, pLine, pitch); + else + { + for (uint32_t i = 0; i < width; i++) + { + pDst[i * 2 + 0] = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + pDst[i * 2 + 1] = pLine[i * 2 + 1]; + } + } + break; + case 3: + for (uint32_t i = 0; i < width; i++) + { + uint8_t c = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + pDst[i * 3 + 0] = c; + pDst[i * 3 + 1] = c; + pDst[i * 3 + 2] = c; + } + break; + case 4: + for (uint32_t i = 0; i < width; i++) + { + uint8_t c = dec.m_img_pal[pLine[i * 2 + 0] * 3]; + pDst[i * 4 + 0] = c; + pDst[i * 4 + 1] = c; + pDst[i * 4 + 2] = c; + pDst[i * 4 + 3] = pLine[i * 2 + 1]; + } + break; + } + + break; + } + case PNG_COLOR_TYPE_PALETTIZED: + { + assert(line_bytes == width); + + switch (desired_chans) + { + case 1: + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &dec.m_img_pal[pLine[i] * 3]; + pDst[i] = get_709_luma(p[0], p[1], p[2]); + } + break; + case 2: + if (dec.m_trns_flag) + { + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &dec.m_img_pal[pLine[i] * 3]; + pDst[i * 2 + 0] = get_709_luma(p[0], p[1], p[2]); + pDst[i * 2 + 1] = (uint8_t)dec.m_trns_value[pLine[i]]; + } + } + else + { + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &dec.m_img_pal[pLine[i] * 3]; + pDst[i * 2 + 0] = get_709_luma(p[0], p[1], p[2]); + pDst[i * 2 + 1] = 255; + } + } + break; + case 3: + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &dec.m_img_pal[pLine[i] * 3]; + pDst[i * 3 + 0] = p[0]; + pDst[i * 3 + 1] = p[1]; + pDst[i * 3 + 2] = p[2]; + } + break; + case 4: + if (dec.m_trns_flag) + { + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &dec.m_img_pal[pLine[i] * 3]; + pDst[i * 4 + 0] = p[0]; + pDst[i * 4 + 1] = p[1]; + pDst[i * 4 + 2] = p[2]; + pDst[i * 4 + 3] = (uint8_t)dec.m_trns_value[pLine[i]]; + } + } + else + { + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &dec.m_img_pal[pLine[i] * 3]; + pDst[i * 4 + 0] = p[0]; + pDst[i * 4 + 1] = p[1]; + pDst[i * 4 + 2] = p[2]; + pDst[i * 4 + 3] = 255; + } + } + break; + } + + break; + } + case PNG_COLOR_TYPE_TRUECOLOR: + case PNG_COLOR_TYPE_TRUECOLOR_ALPHA: + { + assert(line_bytes == width * 4); + + switch (desired_chans) + { + case 1: + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &pLine[i * 4]; + pDst[i] = get_709_luma(p[0], p[1], p[2]); + } + break; + case 2: + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &pLine[i * 4]; + pDst[i * 2 + 0] = get_709_luma(p[0], p[1], p[2]); + pDst[i * 2 + 1] = p[3]; + } + break; + case 3: + for (uint32_t i = 0; i < width; i++) + { + const uint8_t* p = &pLine[i * 4]; + pDst[i * 3 + 0] = p[0]; + pDst[i * 3 + 1] = p[1]; + pDst[i * 3 + 2] = p[2]; + } + break; + case 4: + memcpy(pDst, pLine, pitch); + break; + } + + break; + } + default: + assert(0); + break; + } + + } // y + + return pBuf; +} + +} // namespace pv_png + +/* + This is free and unencumbered software released into the public domain. + + Anyone is free to copy, modify, publish, use, compile, sell, or + distribute this software, either in source code form or as a compiled + binary, for any purpose, commercial or non-commercial, and by any + means. + + In jurisdictions that recognize copyright laws, the author or authors + of this software dedicate any and all copyright interest in the + software to the public domain. We make this dedication for the benefit + of the public at large and to the detriment of our heirs and + successors. We intend this dedication to be an overt act of + relinquishment in perpetuity of all present and future rights to this + software under copyright law. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR + OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + OTHER DEALINGS IN THE SOFTWARE. + + For more information, please refer to <http://unlicense.org/> + + Richard Geldreich, Jr. + 1/20/2022 +*/ |