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 = 0;
+ Lisp_Object file;
+ int rc, width, height, x, y, i, j;
XImagePtr ximg;
ColorMapObject *gif_color_map;
unsigned long pixel_colors[256];
GifFileType *gif;
- Lisp_Object image;
- int ino, image_height, image_width;
+ int image_height, image_width;
gif_memory_source memsrc;
- unsigned char *raster;
- unsigned int transparency_color_index IF_LINT (= 0);
-
- specified_file = image_spec_value (img->spec, QCfile, NULL);
- specified_data = image_spec_value (img->spec, QCdata, NULL);
+ Lisp_Object specified_bg = image_spec_value (img->spec, QCbackground, NULL);
+ Lisp_Object specified_file = image_spec_value (img->spec, QCfile, NULL);
+ Lisp_Object specified_data = image_spec_value (img->spec, QCdata, NULL);
+ unsigned long bgcolor = 0;
+ int idx;
if (NILP (specified_data))
{
/* Read entire contents. */
rc = fn_DGifSlurp (gif);
- if (rc == GIF_ERROR)
+ if (rc == GIF_ERROR || gif->ImageCount <= 0)
{
image_error ("Error reading `%s'", img->spec, Qnil);
fn_DGifCloseFile (gif);
return 0;
}
- image = image_spec_value (img->spec, QCindex, NULL);
- ino = INTEGERP (image) ? XFASTINT (image) : 0;
- if (ino >= gif->ImageCount)
- {
- image_error ("Invalid image number `%s' in image `%s'",
- image, img->spec);
- fn_DGifCloseFile (gif);
- 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)
+ /* Which sub-image are we to display? */
+ {
+ Lisp_Object index = image_spec_value (img->spec, QCindex, NULL);
+ idx = INTEGERP (index) ? XFASTINT (index) : 0;
+ if (idx < 0 || idx >= gif->ImageCount)
{
- transparent_p = 1;
- transparency_color_index
- = (unsigned char) gif->SavedImages[ino].ExtensionBlocks[i].Bytes[3];
+ image_error ("Invalid image number `%s' in image `%s'",
+ index, img->spec);
+ fn_DGifCloseFile (gif);
+ return 0;
}
+ }
- 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;
+ img->corners[TOP_CORNER] = gif->SavedImages[idx].ImageDesc.Top;
+ img->corners[LEFT_CORNER] = gif->SavedImages[idx].ImageDesc.Left;
+ image_height = gif->SavedImages[idx].ImageDesc.Height;
img->corners[BOT_CORNER] = img->corners[TOP_CORNER] + image_height;
- image_width = gif->SavedImages[ino].ImageDesc.Width;
+ image_width = gif->SavedImages[idx].ImageDesc.Width;
img->corners[RIGHT_CORNER] = img->corners[LEFT_CORNER] + image_width;
width = img->width = max (gif->SWidth,
return 0;
}
- /* Allocate colors. */
- gif_color_map = gif->SavedImages[ino].ImageDesc.ColorMap;
- if (!gif_color_map)
- gif_color_map = gif->SColorMap;
- init_color_table ();
- memset (pixel_colors, 0, sizeof pixel_colors);
-
- if (gif_color_map)
- for (i = 0; i < gif_color_map->ColorCount; ++i)
- {
- 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
- img->colors = colors_in_color_table (&img->ncolors);
- free_color_table ();
-#endif /* COLOR_TABLE_SUPPORT */
-
- /* Clear the part of the screen image that are not covered by
- the image from the GIF file. Full animated GIF support
- requires more than can be done here (see the gif89 spec,
- disposal methods). Let's simply assume that the part
- not covered by a sub-image is in the frame's background color. */
+ /* Clear the part of the screen image not covered by the image.
+ Full animated GIF support requires more here (see the gif89 spec,
+ disposal methods). Let's simply assume that the part not covered
+ by a sub-image is in the frame's background color. */
for (y = 0; y < img->corners[TOP_CORNER]; ++y)
for (x = 0; x < width; ++x)
XPutPixel (ximg, x, y, FRAME_BACKGROUND_PIXEL (f));
XPutPixel (ximg, x, y, FRAME_BACKGROUND_PIXEL (f));
}
- /* Read the GIF image into the X image. We use a local variable
- `raster' here because RasterBits below is a char *, and invites
- problems with bytes >= 0x80. */
- raster = (unsigned char *) gif->SavedImages[ino].RasterBits;
-
- if (gif->SavedImages[ino].ImageDesc.Interlace)
- {
- int pass;
- int row = interlace_start[0];
+ /* Read the GIF image into the X image. */
- pass = 0;
+ /* FIXME: With the current implementation, loading an animated gif
+ is quadratic in the number of animation frames, since each frame
+ is a separate struct image. We must provide a way for a single
+ gif_load call to construct and save all animation frames. */
- for (y = 0; y < image_height; y++)
+ init_color_table ();
+ if (STRINGP (specified_bg))
+ bgcolor = x_alloc_image_color (f, img, specified_bg,
+ FRAME_BACKGROUND_PIXEL (f));
+ for (j = 0; j <= idx; ++j)
+ {
+ /* We use a local variable `raster' here because RasterBits is a
+ char *, which invites problems with bytes >= 0x80. */
+ struct SavedImage *subimage = gif->SavedImages + j;
+ unsigned char *raster = (unsigned char *) subimage->RasterBits;
+ int transparency_color_index = -1;
+ int disposal = 0;
+
+ /* Find the Graphic Control Extension block for this sub-image.
+ Extract the disposal method and transparency color. */
+ for (i = 0; i < subimage->ExtensionBlockCount; i++)
{
- if (row >= image_height)
- {
- row = interlace_start[++pass];
- while (row >= image_height)
- row = interlace_start[++pass];
- }
+ ExtensionBlock *extblock = subimage->ExtensionBlocks + i;
- for (x = 0; x < image_width; x++)
+ if ((extblock->Function == GIF_LOCAL_DESCRIPTOR_EXTENSION)
+ && extblock->ByteCount == 4
+ && extblock->Bytes[0] & 1)
{
- int c = raster[(y * image_width) + x];
- XPutPixel (ximg, x + img->corners[LEFT_CORNER],
- row + img->corners[TOP_CORNER], pixel_colors[c]);
+ /* From gif89a spec: 1 = "keep in place", 2 = "restore
+ to background". Treat any other value like 2. */
+ disposal = (extblock->Bytes[0] >> 2) & 7;
+ transparency_color_index = extblock->Bytes[3];
+ break;
}
-
- row += interlace_increment[pass];
}
- }
- else
- {
- for (y = 0; y < image_height; ++y)
- for (x = 0; x < image_width; ++x)
+
+ /* We can't "keep in place" the first subimage. */
+ if (j == 0)
+ disposal = 2;
+
+ /* Allocate subimage colors. */
+ memset (pixel_colors, 0, sizeof pixel_colors);
+ gif_color_map = subimage->ImageDesc.ColorMap;
+ if (!gif_color_map)
+ gif_color_map = gif->SColorMap;
+
+ if (gif_color_map)
+ for (i = 0; i < gif_color_map->ColorCount; ++i)
{
- int c = raster[y * image_width + x];
- XPutPixel (ximg, x + img->corners[LEFT_CORNER],
- y + img->corners[TOP_CORNER], pixel_colors[c]);
+ if (transparency_color_index == i)
+ pixel_colors[i] = STRINGP (specified_bg)
+ ? bgcolor : 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);
+ }
}
+
+ /* Apply the pixel values. */
+ if (gif->SavedImages[j].ImageDesc.Interlace)
+ {
+ int row, pass;
+
+ for (y = 0, row = interlace_start[0], pass = 0;
+ y < image_height;
+ y++, row += interlace_increment[pass])
+ {
+ if (row >= image_height)
+ {
+ row = interlace_start[++pass];
+ while (row >= image_height)
+ row = interlace_start[++pass];
+ }
+
+ for (x = 0; x < image_width; x++)
+ {
+ int c = raster[y * image_width + x];
+ if (transparency_color_index != c || disposal != 1)
+ XPutPixel (ximg, x + img->corners[LEFT_CORNER],
+ row + img->corners[TOP_CORNER], pixel_colors[c]);
+ }
+ }
+ }
+ else
+ {
+ for (y = 0; y < image_height; ++y)
+ for (x = 0; x < image_width; ++x)
+ {
+ int c = raster[y * image_width + x];
+ if (transparency_color_index != c || disposal != 1)
+ XPutPixel (ximg, x + img->corners[LEFT_CORNER],
+ y + img->corners[TOP_CORNER], pixel_colors[c]);
+ }
+ }
}
+#ifdef COLOR_TABLE_SUPPORT
+ img->colors = colors_in_color_table (&img->ncolors);
+ free_color_table ();
+#endif /* COLOR_TABLE_SUPPORT */
+
/* Save GIF image extension data for `image-metadata'.
Format is (count IMAGES extension-data (FUNCTION "BYTES" ...)). */
img->data.lisp_val = Qnil;
- if (gif->SavedImages[ino].ExtensionBlockCount > 0)
+ if (gif->SavedImages[idx].ExtensionBlockCount > 0)
{
- ExtensionBlock *ext = gif->SavedImages[ino].ExtensionBlocks;
- for (i = 0; i < gif->SavedImages[ino].ExtensionBlockCount; i++, ext++)
+ ExtensionBlock *ext = gif->SavedImages[idx].ExtensionBlocks;
+ for (i = 0; i < gif->SavedImages[idx].ExtensionBlockCount; i++, ext++)
/* Append (... FUNCTION "BYTES") */
img->data.lisp_val = Fcons (make_unibyte_string (ext->Bytes, ext->ByteCount),
Fcons (make_number (ext->Function),
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