forked from AuroraMiddleware/gtk
42311804a4
io-png.c: changed g_malloc call for pixles to art_alloc (to be "correct") io-gif.c: implemented GIF file loading.
157 lines
3.5 KiB
C
157 lines
3.5 KiB
C
/*
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* io-png.c: GdkPixBuf I/O for GIF files.
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* ...second verse, same as the first...
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*
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* Author:
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* Mark Crichton <crichton@gimp.org>
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*
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*/
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#include <config.h>
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#include <stdio.h>
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#include <glib.h>
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#include "gdk-pixbuf.h"
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#include "gdk-pixbuf-io.h"
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#include <gif_lib.h>
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/* Shared library entry point */
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GdkPixBuf *image_load(FILE * f)
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{
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gint fn, is_trans, done;
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gint t_color = -1;
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gint w, h, i, j;
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art_u8 *pixels, *tmpptr;
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GifFileType *gif;
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GifRowType *rows;
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GifRecordType rec;
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ColorMapObject *cmap;
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int intoffset[] = {0, 4, 2, 1};
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int intjump[] = {8, 8, 4, 2};
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GdkPixBuf *pixbuf;
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g_return_val_if_fail(f != NULL, NULL);
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fn = fileno(f);
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gif = DGifOpenFileHandle(fn);
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if (!gif) {
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g_error("DGifOpenFilehandle FAILED");
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PrintGifError();
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return NULL;
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}
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/* Now we do the ungodly mess of loading a GIF image
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* I used to remember when I liked this file format...
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* of course, I still coded in assembler then.
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* This comes from gdk_imlib, with some cleanups.
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*/
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do {
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if (DGifGetRecordType(gif, &rec) == GIF_ERROR) {
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PrintGifError();
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rec = TERMINATE_RECORD_TYPE;
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}
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if ((rec == IMAGE_DESC_RECORD_TYPE) && (!done)) {
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if (DGifGetImageDesc(gif) == GIF_ERROR) {
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PrintGifError();
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rec = TERMINATE_RECORD_TYPE;
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}
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w = gif->Image.Width;
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h = gif->Image.Height;
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rows = g_malloc(h * sizeof(GifRowType *));
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if (!rows) {
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DGifCloseFile(gif);
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return NULL;
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}
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for (i = 0; i < h; i++) {
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rows[i] = g_malloc(w * sizeof(GifPixelType));
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if (!rows[i]) {
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DGifCloseFile(gif);
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for (i = 0; i < h; i++)
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if (rows[i])
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g_free(rows[i]);
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free(rows);
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return NULL;
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}
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}
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if (gif->Image.Interlace) {
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for (i = 0; i < 4; i++) {
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for (j = intoffset[i]; j < h; j += intjump[i])
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DGifGetLine(gif, rows[j], w);
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}
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} else {
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for (i = 0; i < h; i++)
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DGifGetLine(gif, rows[i], w);
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}
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done = TRUE;
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} else if (rec == EXTENSION_RECORD_TYPE) {
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gint ext_code;
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GifByteType *ext;
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DGifGetExtension(gif, &ext_code, &ext);
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while (ext) {
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if ((ext_code == GRAPHICS_EXT_FUNC_CODE) &&
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(ext[1] & 1) && (t_color < 0)) {
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is_trans = TRUE;
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t_color = (gint) ext[4];
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}
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ext = NULL;
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DGifGetExtensionNext(gif, &ext);
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}
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}
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}
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while (rec != TERMINATE_RECORD_TYPE);
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/* Ok, we're loaded, now to convert from indexed -> RGB
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* with alpha if necessary
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*/
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if (is_trans)
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pixels = art_alloc(h * w * 4);
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else
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pixels = art_alloc(h * w * 3);
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tmpptr = pixels;
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if (!pixels)
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return NULL;
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/* The meat of the transformation */
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/* Get the right palette */
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cmap = (gif->Image.ColorMap ? gif->Image.ColorMap : gif->SColorMap);
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/* Unindex the data, and pack it in RGB(A) order.
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* Note for transparent GIFs, the alpha is set to 0
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* for the transparent color, and 0xFF for everything else.
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* I think that's right...
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*/
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for (i = 0; i < h; i++) {
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for (j = 0; j < w; j++) {
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tmpptr[0] = cmap->Colors[rows[i][j]].Red;
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tmpptr[1] = cmap->Colors[rows[i][j]].Green;
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tmpptr[2] = cmap->Colors[rows[i][j]].Blue;
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if (is_trans && (rows[i][j] == t_color))
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tmpptr[3] = 0;
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else
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tmpptr[3] = 0xFF;
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tmpptr += (is_trans ? 3 : 4);
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}
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}
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/* Ok, now stuff the GdkPixBuf with goodies */
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pixbuf = g_new(GdkPixBuf, 1);
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if (is_trans)
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pixbuf->art_pixbuf = art_pixbuf_new_rgba(pixels, w, h, (w * 4));
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else
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pixbuf->art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, (w * 3));
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/* Ok, I'm anal...shoot me */
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if (!(pixbuf->art_pixbuf))
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return NULL;
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pixbuf->ref_count = 0;
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pixbuf->unref_func = NULL;
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return pixbuf;
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}
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