+ DBG("libungif_read_data()");
+
+ struct libungif_read_data *rd = io->read_data;
+ GifFileType *gif = rd->gif;
+ SavedImage *image = gif->SavedImages;
+
+ /* Prepare image */
+ struct image_io_read_data_internals rdi;
+ uns read_flags = io->flags;
+ uns cs = read_flags & IMAGE_COLOR_SPACE;
+ if (cs != COLOR_SPACE_GRAYSCALE && cs != COLOR_SPACE_RGB)
+ read_flags = (read_flags & ~IMAGE_COLOR_SPACE & IMAGE_CHANNELS_FORMAT) | COLOR_SPACE_RGB;
+ if (unlikely(!image_io_read_data_prepare(&rdi, io, image->ImageDesc.Width, image->ImageDesc.Height, read_flags)))
+ {
+ DGifCloseFile(gif);
+ return 0;
+ }
+
+ /* Get pixels and palette */
+ byte *pixels = (byte *)image->RasterBits;
+ ColorMapObject *color_map = image->ImageDesc.ColorMap ? : gif->SColorMap;
+ GifColorType *palette = color_map->Colors;
+ byte *img_end = rdi.image->pixels + rdi.image->image_size;
+
+ /* Handle deinterlacing */
+ uns dein_step, dein_next;
+ if (image->ImageDesc.Interlace)
+ {
+ DBG("Deinterlaced image");
+ dein_step = dein_next = rdi.image->row_size << 3;
+ }
+ else
+ dein_step = dein_next = rdi.image->row_size;
+
+ /* Convert pixels */
+ switch (rdi.image->pixel_size)
+ {
+ case 1:
+ {
+ byte pal[256], *pal_pos = pal, *pal_end = pal + 256;
+ for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos++, palette++)
+ *pal_pos = rgb_to_gray_func(palette->Red, palette->Green, palette->Blue);
+ if (pal_pos != pal_end)
+ bzero(pal_pos, pal_end - pal_pos);
+ if (rd->transparent_index >= 0 && (io->flags & IMAGE_IO_USE_BACKGROUND))
+ if (!color_put(io->context, &io->background_color, pal + rd->transparent_index, COLOR_SPACE_GRAYSCALE))
+ {
+ DGifCloseFile(gif);
+ return 0;
+ }
+# define DO_ROW_END do{ \
+ walk_row_start += dein_step; \
+ while (walk_row_start >= img_end) \
+ { uns n = dein_next >> 1; walk_row_start = rdi.image->pixels + n, dein_step = dein_next; dein_next = n; } \
+ }while(0)
+# define IMAGE_WALK_PREFIX(x) walk_##x
+# define IMAGE_WALK_INLINE
+# define IMAGE_WALK_IMAGE (rdi.image)
+# define IMAGE_WALK_UNROLL 4
+# define IMAGE_WALK_COL_STEP 1
+# define IMAGE_WALK_ROW_STEP 0
+# define IMAGE_WALK_DO_STEP do{ *walk_pos = pal[*pixels++]; }while(0)
+# define IMAGE_WALK_DO_ROW_END DO_ROW_END
+# include "images/image-walk.h"
+ break;
+ }
+ case 2:
+ {
+ byte pal[256 * 2], *pal_pos = pal, *pal_end = pal + 256 * 2;
+ for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 2, palette++)
+ {
+ pal_pos[0] = rgb_to_gray_func(palette->Red, palette->Green, palette->Blue);
+ pal_pos[1] = 255;
+ }
+ if (pal_pos != pal_end)
+ bzero(pal_pos, pal_end - pal_pos);
+ if (rd->transparent_index >= 0)
+ pal[rd->transparent_index * 2 + 1] = 0;
+# define IMAGE_WALK_PREFIX(x) walk_##x
+# define IMAGE_WALK_INLINE
+# define IMAGE_WALK_IMAGE (rdi.image)
+# define IMAGE_WALK_UNROLL 4
+# define IMAGE_WALK_COL_STEP 2
+# define IMAGE_WALK_ROW_STEP 0
+# define IMAGE_WALK_DO_STEP do{ *(u16 *)walk_pos = ((u16 *)pal)[*pixels++]; }while(0)
+# define IMAGE_WALK_DO_ROW_END DO_ROW_END
+# include "images/image-walk.h"
+ break;
+ }
+ case 3:
+ {
+ byte pal[256 * 4], *pal_pos = pal, *pal_end = pal + 256 * 4;
+ for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 4, palette++)
+ {
+ pal_pos[0] = palette->Red;
+ pal_pos[1] = palette->Green;
+ pal_pos[2] = palette->Blue;
+ }
+ if (pal_pos != pal_end)
+ bzero(pal_pos, pal_end - pal_pos);
+ if (rd->transparent_index >= 0 && (io->flags & IMAGE_IO_USE_BACKGROUND))
+ if (!color_put(io->context, &io->background_color, pal + 4 * rd->transparent_index, COLOR_SPACE_RGB))
+ {
+ DGifCloseFile(gif);
+ return 0;
+ }
+# define IMAGE_WALK_PREFIX(x) walk_##x
+# define IMAGE_WALK_INLINE
+# define IMAGE_WALK_IMAGE (rdi.image)
+# define IMAGE_WALK_UNROLL 4
+# define IMAGE_WALK_COL_STEP 3
+# define IMAGE_WALK_ROW_STEP 0
+# define IMAGE_WALK_DO_STEP do{ byte *p = pal + 4 * (*pixels++); walk_pos[0] = p[0]; walk_pos[1] = p[1]; walk_pos[2] = p[2]; }while(0)
+# define IMAGE_WALK_DO_ROW_END DO_ROW_END
+# include "images/image-walk.h"
+ break;
+ }
+ case 4:
+ {
+ byte pal[256 * 4], *pal_pos = pal, *pal_end = pal + 256 * 4;
+ for (uns i = 0; i < (uns)color_map->ColorCount; i++, pal_pos += 4, palette++)
+ {
+ pal_pos[0] = palette->Red;
+ pal_pos[1] = palette->Green;
+ pal_pos[2] = palette->Blue;
+ pal_pos[3] = 255;
+ }
+ if (pal_pos != pal_end)
+ bzero(pal_pos, pal_end - pal_pos);
+ if (rd->transparent_index >= 0)
+ pal[rd->transparent_index * 4 + 3] = 0;
+# define IMAGE_WALK_PREFIX(x) walk_##x
+# define IMAGE_WALK_INLINE
+# define IMAGE_WALK_IMAGE (rdi.image)
+# define IMAGE_WALK_UNROLL 4
+# define IMAGE_WALK_COL_STEP 4
+# define IMAGE_WALK_ROW_STEP 0
+# define IMAGE_WALK_DO_STEP do{ *(u32 *)walk_pos = ((u32 *)pal)[*pixels++]; }while(0)
+# define IMAGE_WALK_DO_ROW_END DO_ROW_END
+# include "images/image-walk.h"
+ break;
+ }
+ default:
+ ASSERT(0);
+ }
+
+ /* Destroy libungif structure */
+ DGifCloseFile(gif);
+
+ /* Finish image */
+ return image_io_read_data_finish(&rdi, io);