static int
uncompress_image(Gif_Context *gfc, Gif_Image *gfi, Gif_Reader *grr)
{
if (!Gif_CreateUncompressedImage(gfi)) return 0;
gfc->width = gfi->width;
gfc->height = gfi->height;
gfc->image = gfi->image_data;
gfc->maximage = gfi->image_data + gfi->width * gfi->height;
read_image_data(gfc, grr);
return 1;
}
Gif_Image *
merge_image(Gif_Stream *dest, Gif_Stream *src, Gif_Image *srci,
Gt_Frame* srcfr, int same_compressed_ok)
{
Gif_Colormap *imagecm;
int i;
Gif_Colormap *localcm = 0;
Gif_Colormap *destcm = dest->global;
uint8_t map[256]; /* map[input pixel value] == output pixval */
int trivial_map; /* does the map take input pixval --> the same
pixel value for all colors in the image? */
uint8_t inused[256]; /* inused[input pival] == 1 iff used */
uint8_t used[256]; /* used[output pixval K] == 1 iff K was used
in the image */
Gif_Image *desti;
/* mark colors that were actually used in this image */
imagecm = srci->local ? srci->local : src->global;
merge_image_input_colors(inused, srci);
for (i = imagecm ? imagecm->ncol : 0; i != 256; ++i)
if (inused[i]) {
lwarning(srcfr->input_filename, "some colors undefined by colormap");
break;
}
/* map[old_pixel_value] == new_pixel_value */
for (i = 0; i < 256; i++)
map[i] = used[i] = 0;
/* Merge the colormap */
if (merge_colormap_if_possible(dest->global, imagecm)) {
/* Create 'map' and 'used' for global colormap. */
for (i = 0; i != 256; ++i)
if (inused[i]) {
if (imagecm && i < imagecm->ncol)
map[i] = imagecm->col[i].pixel;
else
map[i] = 0;
}
} else {
/* Need a local colormap. */
destcm = localcm = Gif_NewFullColormap(0, 256);
for (i = 0; i != 256; ++i)
if (inused[i]) {
map[i] = localcm->ncol;
localcm->col[localcm->ncol] = imagecm->col[i];
++localcm->ncol;
}
}
trivial_map = 1;
for (i = 0; i != 256; ++i)
if (inused[i]) {
used[map[i]] = 1;
trivial_map = trivial_map && map[i] == i;
}
/* Decide on a transparent index */
if (srci->transparent >= 0) {
int found_transparent = -1;
/* try to keep the map trivial -- prefer same transparent index */
if (trivial_map && !used[srci->transparent])
found_transparent = srci->transparent;
else
for (i = destcm->ncol - 1; i >= 0; i--)
if (!used[i])
found_transparent = i;
/* 1.Aug.1999 - Allow for the case that the transparent index is bigger
than the number of colors we've created thus far. */
if (found_transparent < 0 || found_transparent >= destcm->ncol) {
Gif_Color *c;
found_transparent = destcm->ncol;
/* 1.Aug.1999 - Don't update destcm->ncol -- we want the output colormap
to be as small as possible. */
c = &destcm->col[found_transparent];
if (imagecm && srci->transparent < imagecm->ncol)
*c = imagecm->col[srci->transparent];
c->haspixel = 2;
assert(c->haspixel == 2 && found_transparent < 256);
}
map[srci->transparent] = found_transparent;
if (srci->transparent != found_transparent) trivial_map = 0;
}
assert(destcm->ncol <= 256);
/* Make the new image. */
desti = Gif_NewImage();
desti->identifier = Gif_CopyString(srci->identifier);
if (srci->transparent > -1)
desti->transparent = map[srci->transparent];
desti->delay = srci->delay;
desti->disposal = srci->disposal;
desti->left = srci->left;
desti->top = srci->top;
desti->interlace = srci->interlace;
desti->width = srci->width;
desti->height = srci->height;
desti->local = localcm;
if (trivial_map && same_compressed_ok && srci->compressed) {
desti->compressed_len = srci->compressed_len;
desti->compressed = Gif_NewArray(uint8_t, srci->compressed_len);
desti->free_compressed = Gif_Free;
memcpy(desti->compressed, srci->compressed, srci->compressed_len);
} else {
int i, j;
Gif_CreateUncompressedImage(desti, desti->interlace);
if (trivial_map)
for (j = 0; j < desti->height; j++)
memcpy(desti->img[j], srci->img[j], desti->width);
else
for (j = 0; j < desti->height; j++) {
uint8_t *srcdata = srci->img[j];
uint8_t *destdata = desti->img[j];
for (i = 0; i < desti->width; i++, srcdata++, destdata++)
*destdata = map[*srcdata];
}
}
/* comments and extensions */
if (srci->comment) {
desti->comment = Gif_NewComment();
merge_comments(desti->comment, srci->comment);
}
if (srci->extension_list && !srcfr->no_extensions) {
Gif_Extension* gfex;
for (gfex = srci->extension_list; gfex; gfex = gfex->next)
if (gfex->kind != 255 || !srcfr->no_app_extensions)
Gif_AddExtension(dest, desti, Gif_CopyExtension(gfex));
}
while (srcfr->extensions) {
Gif_Extension* next = srcfr->extensions->next;
Gif_AddExtension(dest, desti, srcfr->extensions);
srcfr->extensions = next;
}
Gif_AddImage(dest, desti);
return desti;
}
