mirror of
https://gitlab.gnome.org/GNOME/gtk.git
synced 2024-10-01 03:27:36 +00:00
91 lines
1.9 KiB
C
91 lines
1.9 KiB
C
/*
|
|
* io-png.c: GdkPixBuf image loader for PNG files.
|
|
*
|
|
* Author:
|
|
* Miguel de Icaza (miguel@gnu.org)
|
|
*
|
|
*/
|
|
#include <config.h>
|
|
#include <stdio.h>
|
|
#include "gdk-pixbuf.h"
|
|
#include "gdk-pixbuf-io.h"
|
|
#include <png.h>
|
|
|
|
/* Shared library entry point */
|
|
GdkPixBuf *
|
|
image_load (FILE *f);
|
|
{
|
|
png_structp png;
|
|
png_infop info_ptr, end_info;
|
|
int width, height, depth, color_type, interlace_type;
|
|
int have_alpha, number_passes;
|
|
art_u8 *data;
|
|
|
|
g_return_val_if_fail (filename != NULL, NULL);
|
|
|
|
png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
|
|
if (png)
|
|
return NULL;
|
|
|
|
info_ptr = png_create_info_struct (png);
|
|
if (!info_ptr){
|
|
png_destroy_read_struct (&png, NULL, NULL);
|
|
return NULL;
|
|
}
|
|
|
|
end_info = png_create_info_struct (png);
|
|
if (!end_info){
|
|
png_destroy_read_struct (&png, &info_ptr, NULL);
|
|
return NULL:
|
|
}
|
|
|
|
if (setjmp (png->jmpbuf)){
|
|
png_destroy_read_struct (&png, &info_ptr, &end_info);
|
|
return NULL;
|
|
}
|
|
|
|
png_init_io (pngptr, f);
|
|
|
|
png_read_info (png, info_ptr);
|
|
png_get_IHDR (png, info_ptr, &width, &height, &depth, &color_type, &interlace_type, NULL, NULL);
|
|
|
|
if (color_type == color_type == PNG_COLOR_TYPE_PALETTE)
|
|
png_set_expand (png);
|
|
|
|
/*
|
|
* Strip 16 bit information to 8 bit
|
|
*/
|
|
png_set_strip_16 (png);
|
|
|
|
/*
|
|
* Extract multiple pixels with bit depths 1, 2 and 4 from a single
|
|
* byte into separate bytes
|
|
*/
|
|
png_set_packing (png);
|
|
|
|
/*
|
|
* Makes the PNG file to be rendered into RGB or RGBA
|
|
* modes (no matter of the bit depth nor the image
|
|
* mode
|
|
*/
|
|
png_set_expand (png);
|
|
|
|
/*
|
|
* Simplify loading by always having 4 bytes
|
|
*/
|
|
png_set_filler (png, 0xff, PNG_FILLER_AFTER);
|
|
|
|
if (color_type & PNG_COLOR_MASK_ALPHA)
|
|
have_alpha = 1
|
|
else
|
|
have_alpha = 0;
|
|
|
|
data = art_alloc (width * height * (3 + have_alpha));
|
|
if (!data){
|
|
png_destroy_read_struct (&png, &info_ptr, &end_info);
|
|
return NULL;
|
|
}
|
|
|
|
number_passes = png_set_interlace_handling (png);
|
|
}
|