mirror of
https://gitlab.freedesktop.org/cairo/cairo.git
synced 2025-12-21 11:00:09 +01:00
a6d9b6a671
Propagate the unsigned char* change down the stack. Add cast since XImage uses char* rather than unsigned char*. Fix memory leak of image data. Switch to use cairo_surface_write_png rather than a custom write_png_argb32. Add test to exercise the cairo_image_surface_create_for_png function.
99 lines
3 KiB
C
99 lines
3 KiB
C
/*
|
|
* Copyright © 2003 USC, Information Sciences Institute
|
|
*
|
|
* Permission to use, copy, modify, distribute, and sell this software
|
|
* and its documentation for any purpose is hereby granted without
|
|
* fee, provided that the above copyright notice appear in all copies
|
|
* and that both that copyright notice and this permission notice
|
|
* appear in supporting documentation, and that the name of the
|
|
* University of Southern California not be used in advertising or
|
|
* publicity pertaining to distribution of the software without
|
|
* specific, written prior permission. The University of Southern
|
|
* California makes no representations about the suitability of this
|
|
* software for any purpose. It is provided "as is" without express
|
|
* or implied warranty.
|
|
*
|
|
* THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
|
|
* REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
|
|
* SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
|
|
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
|
|
* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
|
|
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
|
|
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* Author: Carl D. Worth <cworth@cworth.org>
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <png.h>
|
|
|
|
#include "write-png.h"
|
|
|
|
static void
|
|
unpremultiply_data (png_structp png, png_row_infop row_info, png_bytep data)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < row_info->rowbytes; i += 4) {
|
|
unsigned char *b = &data[i];
|
|
unsigned int pixel;
|
|
unsigned char alpha;
|
|
|
|
memcpy (&pixel, b, sizeof (unsigned int));
|
|
alpha = (pixel & 0xff000000) >> 24;
|
|
if (alpha == 0) {
|
|
b[0] = b[1] = b[2] = b[3] = 0;
|
|
} else {
|
|
b[0] = (((pixel & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
|
|
b[1] = (((pixel & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
|
|
b[2] = (((pixel & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
|
|
b[3] = alpha;
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
write_png_argb32 (unsigned char *buffer, FILE *file,
|
|
int width, int height, int stride)
|
|
{
|
|
int i;
|
|
png_struct *png;
|
|
png_info *info;
|
|
png_byte **rows;
|
|
png_color_16 white;
|
|
|
|
rows = malloc (height * sizeof(png_byte*));
|
|
|
|
for (i = 0; i < height; i++) {
|
|
rows[i] = buffer + i * stride;
|
|
}
|
|
|
|
png = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
|
|
info = png_create_info_struct (png);
|
|
|
|
png_init_io (png, file);
|
|
png_set_IHDR (png, info,
|
|
width, height, 8,
|
|
PNG_COLOR_TYPE_RGB_ALPHA,
|
|
PNG_INTERLACE_NONE,
|
|
PNG_COMPRESSION_TYPE_DEFAULT,
|
|
PNG_FILTER_TYPE_DEFAULT);
|
|
|
|
white.red = 0xff;
|
|
white.blue = 0xff;
|
|
white.green = 0xff;
|
|
png_set_bKGD (png, info, &white);
|
|
|
|
png_set_write_user_transform_fn (png, unpremultiply_data);
|
|
png_set_bgr (png);
|
|
|
|
png_write_info (png, info);
|
|
png_write_image (png, rows);
|
|
png_write_end (png, info);
|
|
|
|
png_destroy_write_struct (&png, &info);
|
|
|
|
free (rows);
|
|
}
|