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0eb096334e
1999-10-27 Federico Mena Quintero <federico@redhat.com> * src/gdk-pixbuf-render.c (gdk_pixbuf_render_threshold_alpha): New function to threshold a pixbuf's alpha channel into a bitmap. * src/gdk-pixbuf.c (gdk_pixbuf_new): Fixed so that it will contemplate future extensions to ArtPixBuf's formats. * src/io-png.c (png_info_callback): Use the new API of gdk_pixbuf_new(). * src/gdk-pixbuf.h (gdk_pixbuf_get_height): Added some convenience macros to fetch the ArtPixBuf's fields.
440 lines
12 KiB
C
440 lines
12 KiB
C
/* GdkPixbuf library - JPEG image loader
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*
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* Copyright (C) 1999 Mark Crichton
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* Copyright (C) 1999 The Free Software Foundation
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*
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* Authors: Mark Crichton <crichton@gimp.org>
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* Federico Mena-Quintero <federico@gimp.org>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#include <config.h>
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#include <stdio.h>
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#include <png.h>
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#include "gdk-pixbuf.h"
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#include "gdk-pixbuf-io.h"
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static void
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setup_png_transformations(png_structp png_read_ptr, png_infop png_info_ptr,
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gboolean *fatal_error_occurred,
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png_uint_32* width_p, png_uint_32* height_p,
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int* color_type_p)
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{
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png_uint_32 width, height;
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int bit_depth, color_type, interlace_type, compression_type, filter_type;
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int channels;
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/* Get the image info */
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png_get_IHDR (png_read_ptr, png_info_ptr,
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&width, &height,
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&bit_depth,
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&color_type,
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&interlace_type,
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&compression_type,
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&filter_type);
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/* set_expand() basically needs to be called unless
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we are already in RGB/RGBA mode
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*/
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if (color_type == PNG_COLOR_TYPE_PALETTE &&
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bit_depth <= 8) {
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/* Convert indexed images to RGB */
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png_set_expand (png_read_ptr);
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} else if (color_type == PNG_COLOR_TYPE_GRAY &&
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bit_depth < 8) {
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/* Convert grayscale to RGB */
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png_set_expand (png_read_ptr);
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} else if (png_get_valid (png_read_ptr,
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png_info_ptr, PNG_INFO_tRNS)) {
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/* If we have transparency header, convert it to alpha
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channel */
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png_set_expand(png_read_ptr);
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} else if (bit_depth < 8) {
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/* If we have < 8 scale it up to 8 */
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png_set_expand(png_read_ptr);
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/* Conceivably, png_set_packing() is a better idea;
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* God only knows how libpng works
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*/
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}
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/* If we are 16-bit, convert to 8-bit */
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if (bit_depth == 16) {
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png_set_strip_16(png_read_ptr);
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}
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/* If gray scale, convert to RGB */
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if (color_type == PNG_COLOR_TYPE_GRAY ||
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color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
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png_set_gray_to_rgb(png_read_ptr);
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}
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/* If interlaced, handle that */
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if (interlace_type != PNG_INTERLACE_NONE) {
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png_set_interlace_handling(png_read_ptr);
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}
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/* Update the info the reflect our transformations */
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png_read_update_info(png_read_ptr, png_info_ptr);
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png_get_IHDR (png_read_ptr, png_info_ptr,
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&width, &height,
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&bit_depth,
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&color_type,
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&interlace_type,
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&compression_type,
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&filter_type);
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*width_p = width;
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*height_p = height;
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*color_type_p = color_type;
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#ifndef G_DISABLE_CHECKS
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/* Check that the new info is what we want */
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if (bit_depth != 8) {
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g_warning("Bits per channel of transformed PNG is %d, not 8.", bit_depth);
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*fatal_error_occurred = TRUE;
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return;
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}
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if ( ! (color_type == PNG_COLOR_TYPE_RGB ||
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color_type == PNG_COLOR_TYPE_RGB_ALPHA) ) {
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g_warning("Transformed PNG not RGB or RGBA.");
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*fatal_error_occurred = TRUE;
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return;
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}
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channels = png_get_channels(png_read_ptr, png_info_ptr);
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if ( ! (channels == 3 || channels == 4) ) {
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g_warning("Transformed PNG has %d channels, must be 3 or 4.", channels);
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*fatal_error_occurred = TRUE;
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return;
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}
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#endif
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}
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/* Destroy notification function for the libart pixbuf */
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static void
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free_buffer (gpointer user_data, gpointer data)
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{
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free (data);
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}
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/* Shared library entry point */
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GdkPixbuf *
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image_load (FILE *f)
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{
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png_structp png_ptr;
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png_infop info_ptr, end_info;
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gboolean failed = FALSE;
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gint i, ctype, bpp;
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png_uint_32 w, h;
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png_bytepp rows;
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guchar *pixels;
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png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
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if (!png_ptr)
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return NULL;
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info_ptr = png_create_info_struct (png_ptr);
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if (!info_ptr) {
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png_destroy_read_struct (&png_ptr, NULL, NULL);
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return NULL;
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}
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end_info = png_create_info_struct (png_ptr);
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if (!end_info) {
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png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
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return NULL;
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}
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if (setjmp (png_ptr->jmpbuf)) {
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png_destroy_read_struct (&png_ptr, &info_ptr, &end_info);
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return NULL;
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}
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png_init_io (png_ptr, f);
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png_read_info (png_ptr, info_ptr);
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setup_png_transformations(png_ptr, info_ptr, &failed, &w, &h, &ctype);
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if (failed) {
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png_destroy_read_struct (&png_ptr, &info_ptr, &end_info);
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return NULL;
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}
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if (ctype & PNG_COLOR_MASK_ALPHA)
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bpp = 4;
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else
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bpp = 3;
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pixels = malloc (w * h * bpp);
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if (!pixels) {
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png_destroy_read_struct (&png_ptr, &info_ptr, &end_info);
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return NULL;
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}
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rows = g_new (png_bytep, h);
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for (i = 0; i < h; i++)
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rows[i] = pixels + i * w * bpp;
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png_read_image (png_ptr, rows);
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png_destroy_read_struct (&png_ptr, &info_ptr, &end_info);
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g_free (rows);
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if (ctype & PNG_COLOR_MASK_ALPHA)
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return gdk_pixbuf_new_from_data (pixels, ART_PIX_RGB, TRUE,
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w, h, w * 4,
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free_buffer, NULL);
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else
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return gdk_pixbuf_new_from_data (pixels, ART_PIX_RGB, FALSE,
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w, h, w * 3,
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free_buffer, NULL);
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}
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/* These avoid the setjmp()/longjmp() crap in libpng */
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static void png_error_callback (png_structp png_read_ptr,
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png_const_charp error_msg);
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static void png_warning_callback(png_structp png_read_ptr,
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png_const_charp warning_msg);
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/* Called at the start of the progressive load */
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static void png_info_callback (png_structp png_read_ptr,
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png_infop png_info_ptr);
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/* Called for each row; note that you will get duplicate row numbers
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for interlaced PNGs */
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static void png_row_callback (png_structp png_read_ptr,
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png_bytep new_row,
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png_uint_32 row_num,
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int pass_num);
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/* Called after reading the entire image */
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static void png_end_callback (png_structp png_read_ptr,
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png_infop png_info_ptr);
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typedef struct _LoadContext LoadContext;
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struct _LoadContext {
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png_structp png_read_ptr;
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png_infop png_info_ptr;
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ModulePreparedNotifyFunc notify_func;
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gpointer notify_user_data;
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GdkPixbuf* pixbuf;
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guint fatal_error_occurred : 1;
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};
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gpointer
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image_begin_load (ModulePreparedNotifyFunc func, gpointer user_data)
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{
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LoadContext* lc;
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lc = g_new0(LoadContext, 1);
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lc->fatal_error_occurred = FALSE;
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lc->notify_func = func;
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lc->notify_user_data = user_data;
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/* Create the main PNG context struct */
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lc->png_read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
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lc, /* error/warning callback data */
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png_error_callback,
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png_warning_callback);
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if (lc->png_read_ptr == NULL) {
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g_free(lc);
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return NULL;
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}
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/* Create the auxiliary context struct */
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lc->png_info_ptr = png_create_info_struct(lc->png_read_ptr);
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if (lc->png_info_ptr == NULL) {
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png_destroy_read_struct(&lc->png_read_ptr, NULL, NULL);
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g_free(lc);
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return NULL;
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}
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png_set_progressive_read_fn(lc->png_read_ptr,
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lc, /* callback data */
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png_info_callback,
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png_row_callback,
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png_end_callback);
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return lc;
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}
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void
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image_stop_load (gpointer context)
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{
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LoadContext* lc = context;
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g_return_if_fail(lc != NULL);
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gdk_pixbuf_unref(lc->pixbuf);
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png_destroy_read_struct(&lc->png_read_ptr, NULL, NULL);
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g_free(lc);
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}
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gboolean
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image_load_increment(gpointer context, guchar *buf, guint size)
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{
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LoadContext* lc = context;
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g_return_val_if_fail(lc != NULL, FALSE);
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/* Invokes our callbacks as needed */
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png_process_data(lc->png_read_ptr, lc->png_info_ptr, buf, size);
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if (lc->fatal_error_occurred)
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return FALSE;
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else
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return TRUE;
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}
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/* Called at the start of the progressive load, once we have image info */
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static void
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png_info_callback (png_structp png_read_ptr,
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png_infop png_info_ptr)
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{
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LoadContext* lc;
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png_uint_32 width, height;
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int color_type;
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gboolean have_alpha = FALSE;
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gboolean failed = FALSE;
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lc = png_get_progressive_ptr(png_read_ptr);
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if (lc->fatal_error_occurred)
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return;
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setup_png_transformations(lc->png_read_ptr,
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lc->png_info_ptr,
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&failed,
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&width, &height, &color_type);
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if (failed) {
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lc->fatal_error_occurred = TRUE;
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return;
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}
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/* If we have alpha, set a flag */
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if (color_type & PNG_COLOR_MASK_ALPHA)
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have_alpha = TRUE;
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lc->pixbuf = gdk_pixbuf_new(ART_PIX_RGB, have_alpha, 8, width, height);
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if (lc->pixbuf == NULL) {
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/* Failed to allocate memory */
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lc->fatal_error_occurred = TRUE;
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return;
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}
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/* Notify the client that we are ready to go */
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if (lc->notify_func)
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(* lc->notify_func) (lc->pixbuf, lc->notify_user_data);
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return;
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}
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/* Called for each row; note that you will get duplicate row numbers
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for interlaced PNGs */
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static void
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png_row_callback (png_structp png_read_ptr,
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png_bytep new_row,
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png_uint_32 row_num,
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int pass_num)
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{
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LoadContext* lc;
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guchar* old_row = NULL;
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lc = png_get_progressive_ptr(png_read_ptr);
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if (lc->fatal_error_occurred)
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return;
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old_row = lc->pixbuf->art_pixbuf->pixels + (row_num * lc->pixbuf->art_pixbuf->rowstride);
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png_progressive_combine_row(lc->png_read_ptr, old_row, new_row);
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}
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/* Called after reading the entire image */
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static void
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png_end_callback (png_structp png_read_ptr,
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png_infop png_info_ptr)
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{
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LoadContext* lc;
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lc = png_get_progressive_ptr(png_read_ptr);
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if (lc->fatal_error_occurred)
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return;
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/* Doesn't do anything for now */
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}
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static void
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png_error_callback(png_structp png_read_ptr,
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png_const_charp error_msg)
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{
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LoadContext* lc;
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lc = png_get_error_ptr(png_read_ptr);
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lc->fatal_error_occurred = TRUE;
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fprintf(stderr, "Fatal error loading PNG: %s\n", error_msg);
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}
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static void
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png_warning_callback(png_structp png_read_ptr,
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png_const_charp warning_msg)
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{
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LoadContext* lc;
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lc = png_get_error_ptr(png_read_ptr);
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fprintf(stderr, "Warning loading PNG: %s\n", warning_msg);
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}
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