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c84756cf38
1999-10-26 Jonathan Blandford <jrb@redhat.com> * src/gdk-pixbuf-loader.h: New Class. Beginning of progrssive loading.
143 lines
3.7 KiB
C
143 lines
3.7 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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/* 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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gint i, depth, ctype, inttype, passes, 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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png_get_IHDR (png_ptr, info_ptr, &w, &h, &depth, &ctype, &inttype, NULL, NULL);
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/* Ok, we want to work with 24 bit images.
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* However, PNG can vary depth per channel.
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* So, we use the png_set_expand function to expand
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* everything into a format libart expects.
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* We also use png_set_strip_16 to reduce down to 8 bit/chan.
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*/
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if (ctype == PNG_COLOR_TYPE_PALETTE && depth <= 8)
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png_set_expand (png_ptr);
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if (ctype == PNG_COLOR_TYPE_GRAY && depth < 8)
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png_set_expand (png_ptr);
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if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS)) {
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png_set_expand (png_ptr);
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g_warning ("FIXME: We are going to crash");
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}
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if (depth == 16)
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png_set_strip_16 (png_ptr);
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/* We also have png "packing" bits into bytes if < 8 */
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if (depth < 8)
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png_set_packing (png_ptr);
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/* Lastly, if the PNG is greyscale, convert to RGB */
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if (ctype == PNG_COLOR_TYPE_GRAY || ctype == PNG_COLOR_TYPE_GRAY_ALPHA)
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png_set_gray_to_rgb (png_ptr);
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/* ...and if we're interlaced... */
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passes = png_set_interlace_handling (png_ptr);
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png_read_update_info (png_ptr, info_ptr);
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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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GdkImage *
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image_load_by_data (void *data, size_t count)
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{
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return NULL;
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}
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