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-rw-r--r--drivers/png/example.c85
1 files changed, 51 insertions, 34 deletions
diff --git a/drivers/png/example.c b/drivers/png/example.c
index ec53a8cdee..7171d9847e 100644
--- a/drivers/png/example.c
+++ b/drivers/png/example.c
@@ -2,8 +2,8 @@
#if 0 /* in case someone actually tries to compile this */
/* example.c - an example of using libpng
- * Last changed in libpng 1.5.7 [December 15, 2011]
- * Maintained 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.19 [August 21, 2014]
+ * Maintained 1998-2014 Glenn Randers-Pehrson
* Maintained 1996, 1997 Andreas Dilger
* Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
*/
@@ -89,7 +89,7 @@ void read_png(char *file_name) /* We need to open the file */
{
png_structp png_ptr;
png_infop info_ptr;
- unsigned int sig_read = 0;
+ int sig_read = 0;
png_uint_32 width, height;
int bit_depth, color_type, interlace_type;
FILE *fp;
@@ -98,7 +98,7 @@ void read_png(char *file_name) /* We need to open the file */
return (ERROR);
#else no_open_file /* prototype 2 */
-void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
+void read_png(FILE *fp, int sig_read) /* File is already open */
{
png_structp png_ptr;
png_infop info_ptr;
@@ -188,7 +188,7 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
* are mutually exclusive.
*/
- /* Tell libpng to strip 16 bit/color files down to 8 bits/color.
+ /* Tell libpng to strip 16 bits/color files down to 8 bits/color.
* Use accurate scaling if it's available, otherwise just chop off the
* low byte.
*/
@@ -259,9 +259,9 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
/* If we don't have another value */
else
{
- screen_gamma = 2.2; /* A good guess for a PC monitor in a dimly
- lit room */
- screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */
+ screen_gamma = PNG_DEFAULT_sRGB; /* A good guess for a PC monitor
+ in a dimly lit room */
+ screen_gamma = PNG_GAMMA_MAC_18 or 1.0; /* Good guesses for Mac systems */
}
/* Tell libpng to handle the gamma conversion for you. The final call
@@ -273,7 +273,7 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
int intent;
if (png_get_sRGB(png_ptr, info_ptr, &intent))
- png_set_gamma(png_ptr, screen_gamma, 0.45455);
+ png_set_gamma(png_ptr, screen_gamma, PNG_DEFAULT_sRGB);
else
{
double image_gamma;
@@ -284,7 +284,7 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
}
#ifdef PNG_READ_QUANTIZE_SUPPORTED
- /* Quantize RGB files down to 8 bit palette or reduce palettes
+ /* Quantize RGB files down to 8-bit palette or reduce palettes
* to the number of colors available on your screen.
*/
if (color_type & PNG_COLOR_MASK_COLOR)
@@ -336,7 +336,7 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
/* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
png_set_swap_alpha(png_ptr);
- /* Swap bytes of 16 bit files to least significant byte first */
+ /* Swap bytes of 16-bit files to least significant byte first */
png_set_swap(png_ptr);
/* Add filler (or alpha) byte (before/after each RGB triplet) */
@@ -695,25 +695,38 @@ void write_png(char *file_name /* , ... other image information ... */)
png_set_gAMA(png_ptr, info_ptr, gamma);
/* Optionally write comments into the image */
- text_ptr[0].key = "Title";
- text_ptr[0].text = "Mona Lisa";
- text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr[0].itxt_length = 0;
- text_ptr[0].lang = NULL;
- text_ptr[0].lang_key = NULL;
- text_ptr[1].key = "Author";
- text_ptr[1].text = "Leonardo DaVinci";
- text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr[1].itxt_length = 0;
- text_ptr[1].lang = NULL;
- text_ptr[1].lang_key = NULL;
- text_ptr[2].key = "Description";
- text_ptr[2].text = "<long text>";
- text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
- text_ptr[2].itxt_length = 0;
- text_ptr[2].lang = NULL;
- text_ptr[2].lang_key = NULL;
- png_set_text(png_ptr, info_ptr, text_ptr, 3);
+ {
+ png_text text_ptr[3];
+
+ char key0[]="Title";
+ char text0[]="Mona Lisa";
+ text_ptr[0].key = key0;
+ text_ptr[0].text = text0;
+ text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr[0].itxt_length = 0;
+ text_ptr[0].lang = NULL;
+ text_ptr[0].lang_key = NULL;
+
+ char key1[]="Author";
+ char text1[]="Leonardo DaVinci";
+ text_ptr[1].key = key1;
+ text_ptr[1].text = text1;
+ text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr[1].itxt_length = 0;
+ text_ptr[1].lang = NULL;
+ text_ptr[1].lang_key = NULL;
+
+ char key2[]="Description";
+ char text2[]="<long text>";
+ text_ptr[2].key = key2;
+ text_ptr[2].text = text2;
+ text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
+ text_ptr[2].itxt_length = 0;
+ text_ptr[2].lang = NULL;
+ text_ptr[2].lang_key = NULL;
+
+ png_set_text(write_ptr, write_info_ptr, text_ptr, 3);
+ }
/* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs */
@@ -737,7 +750,7 @@ void write_png(char *file_name /* , ... other image information ... */)
*/
/* Once we write out the header, the compression type on the text
- * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
+ * chunk gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
* PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
* at the end.
*/
@@ -771,11 +784,11 @@ void write_png(char *file_name /* , ... other image information ... */)
/* Swap bytes of 16-bit files to most significant byte first */
png_set_swap(png_ptr);
- /* Swap bits of 1, 2, 4 bit packed pixel formats */
+ /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */
png_set_packswap(png_ptr);
/* Turn on interlace handling if you are not using png_write_image() */
- if (interlacing)
+ if (interlacing != 0)
number_passes = png_set_interlace_handling(png_ptr);
else
@@ -786,12 +799,16 @@ void write_png(char *file_name /* , ... other image information ... */)
* use the first method if you aren't handling interlacing yourself.
*/
png_uint_32 k, height, width;
- png_byte image[height][width*bytes_per_pixel];
+
+ /* In this example, "image" is a one-dimensional array of bytes */
+ png_byte image[height*width*bytes_per_pixel];
+
png_bytep row_pointers[height];
if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
png_error (png_ptr, "Image is too tall to process in memory");
+ /* Set up pointers into your "image" byte array */
for (k = 0; k < height; k++)
row_pointers[k] = image + k*width*bytes_per_pixel;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-07 05:47:17 +0000