Commit 17c0c952 authored by Julien Danjou's avatar Julien Danjou Committed by Chong Yidong

Support for gif transparency.

* image.c (gif_load): Add support for transparency and specified
:background.
parent 7977dcb8
2010-11-03 Julien Danjou <julien@danjou.info>
* image.c (gif_load): Add support for transparency and specified
:background.
2010-11-01 Kenichi Handa <handa@m17n.org>
* dispextern.h (lookup_glyphless_char_display): Extern it.
......
......@@ -7096,12 +7096,15 @@ gif_read_from_memory (GifFileType *file, GifByteType *buf, int len)
static const int interlace_start[] = {0, 4, 2, 1};
static const int interlace_increment[] = {8, 8, 4, 2};
#define GIF_LOCAL_DESCRIPTOR_EXTENSION 249
static int
gif_load (struct frame *f, struct image *img)
{
Lisp_Object file, specified_file;
Lisp_Object specified_data;
int rc, width, height, x, y, i;
boolean transparent_p;
XImagePtr ximg;
ColorMapObject *gif_color_map;
unsigned long pixel_colors[256];
......@@ -7110,6 +7113,7 @@ gif_load (struct frame *f, struct image *img)
int ino, image_height, image_width;
gif_memory_source memsrc;
unsigned char *raster;
unsigned int transparency_color_index;
specified_file = image_spec_value (img->spec, QCfile, NULL);
specified_data = image_spec_value (img->spec, QCdata, NULL);
......@@ -7182,6 +7186,18 @@ gif_load (struct frame *f, struct image *img)
return 0;
}
for (i = 0; i < gif->SavedImages[ino].ExtensionBlockCount; i++)
if ((gif->SavedImages[ino].ExtensionBlocks[i].Function
== GIF_LOCAL_DESCRIPTOR_EXTENSION)
&& gif->SavedImages[ino].ExtensionBlocks[i].ByteCount == 4
/* Transparency enabled? */
&& gif->SavedImages[ino].ExtensionBlocks[i].Bytes[0] & 1)
{
transparent_p = 1;
transparency_color_index
= (unsigned char) gif->SavedImages[ino].ExtensionBlocks[i].Bytes[3];
}
img->corners[TOP_CORNER] = gif->SavedImages[ino].ImageDesc.Top;
img->corners[LEFT_CORNER] = gif->SavedImages[ino].ImageDesc.Left;
image_height = gif->SavedImages[ino].ImageDesc.Height;
......@@ -7220,10 +7236,22 @@ gif_load (struct frame *f, struct image *img)
if (gif_color_map)
for (i = 0; i < gif_color_map->ColorCount; ++i)
{
int r = gif_color_map->Colors[i].Red << 8;
int g = gif_color_map->Colors[i].Green << 8;
int b = gif_color_map->Colors[i].Blue << 8;
pixel_colors[i] = lookup_rgb_color (f, r, g, b);
if (transparent_p && transparency_color_index == i)
{
Lisp_Object specified_bg
= image_spec_value (img->spec, QCbackground, NULL);
pixel_colors[i] = STRINGP (specified_bg)
? x_alloc_image_color (f, img, specified_bg,
FRAME_BACKGROUND_PIXEL (f))
: FRAME_BACKGROUND_PIXEL (f);
}
else
{
int r = gif_color_map->Colors[i].Red << 8;
int g = gif_color_map->Colors[i].Green << 8;
int b = gif_color_map->Colors[i].Blue << 8;
pixel_colors[i] = lookup_rgb_color (f, r, g, b);
}
}
#ifdef COLOR_TABLE_SUPPORT
......
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