static int
initialize_optimizer(Gif_Stream *gfs)
{
int i;
if (gfs->nimages < 1)
return 0;
/* combine colormaps */
all_colormap = Gif_NewFullColormap(1, 384);
all_colormap->col[0].gfc_red = 255;
all_colormap->col[0].gfc_green = 255;
all_colormap->col[0].gfc_blue = 255;
in_global_map = gfs->global;
if (!in_global_map) {
Gif_Color *col;
in_global_map = Gif_NewFullColormap(256, 256);
col = in_global_map->col;
for (i = 0; i < 256; i++, col++)
col->gfc_red = col->gfc_green = col->gfc_blue = i;
}
{
int any_globals = 0;
int first_transparent = -1;
kchist_init(&all_colormap_hist);
for (i = 0; i < gfs->nimages; i++) {
Gif_Image *gfi = gfs->images[i];
if (gfi->local)
all_colormap_add(gfi->local);
else
any_globals = 1;
if (gfi->transparent >= 0 && first_transparent < 0)
first_transparent = i;
}
if (any_globals)
all_colormap_add(in_global_map);
kchist_cleanup(&all_colormap_hist);
/* try and maintain transparency's pixel value */
if (first_transparent >= 0) {
Gif_Image *gfi = gfs->images[first_transparent];
Gif_Colormap *gfcm = gfi->local ? gfi->local : gfs->global;
all_colormap->col[TRANSP] = gfcm->col[gfi->transparent];
}
}
/* find screen_width and screen_height, and clip all images to screen */
Gif_CalculateScreenSize(gfs, 0);
screen_width = gfs->screen_width;
screen_height = gfs->screen_height;
for (i = 0; i < gfs->nimages; i++)
Gif_ClipImage(gfs->images[i], 0, 0, screen_width, screen_height);
/* choose background */
if (gfs->images[0]->transparent < 0
&& gfs->global && gfs->background < in_global_map->ncol)
background = in_global_map->col[gfs->background].pixel;
else
background = TRANSP;
return 1;
}
static int
apply_image(int is_second, Gif_Stream *gfs, int imageno, uint16_t background)
{
int i, x, y, any_change;
Gif_Image *gfi = gfs->images[imageno];
Gif_Image *pgfi = imageno ? gfs->images[imageno - 1] : 0;
int width = gfi->width;
uint16_t map[256];
uint16_t *data = gdata[is_second];
uint16_t *last = glast[is_second];
Gif_Colormap *gfcm = gfi->local ? gfi->local : gfs->global;
/* set up colormap */
for (i = 0; i < 256; i++)
map[i] = 1;
if (gfs)
for (i = 0; i < gfcm->ncol; i++)
map[i] = gfcm->col[i].pixel;
if (gfi->transparent >= 0 && gfi->transparent < 256)
map[gfi->transparent] = TRANSP;
/* if this image's disposal is 'previous', save the post-disposal version in
'scratch' */
if (gfi->disposal == GIF_DISPOSAL_PREVIOUS) {
copy_area(scratch, data, gfi->left, gfi->top, gfi->width, gfi->height);
if (pgfi && pgfi->disposal == GIF_DISPOSAL_PREVIOUS)
copy_area(scratch, last, pgfi->left, pgfi->top, pgfi->width, pgfi->height);
else if (pgfi && pgfi->disposal == GIF_DISPOSAL_BACKGROUND)
fill_area(scratch, pgfi->left, pgfi->top, pgfi->width, pgfi->height, background);
}
/* uncompress and clip */
Gif_UncompressImage(gfs, gfi);
Gif_ClipImage(gfi, 0, 0, screen_width, screen_height);
any_change = imageno == 0;
{
int lf = 0, tp = 0, rt = 0, bt = 0;
expand_bounds(&lf, &tp, &rt, &bt, gfi);
if (pgfi && pgfi->disposal == GIF_DISPOSAL_PREVIOUS)
expand_bounds(&lf, &tp, &rt, &bt, pgfi);
else if (pgfi && pgfi->disposal == GIF_DISPOSAL_BACKGROUND) {
expand_bounds(&lf, &tp, &rt, &bt, pgfi);
fill_area(last, pgfi->left, pgfi->top, pgfi->width, pgfi->height, background);
} else
pgfi = 0;
for (y = tp; y < bt; ++y) {
uint16_t *outd = data + screen_width * y + lf;
if (!any_change)
memcpy(line, outd, (rt - lf) * sizeof(uint16_t));
if (pgfi && y >= pgfi->top && y < pgfi->top + pgfi->height)
memcpy(outd + pgfi->left - lf,
last + screen_width * y + pgfi->left,
pgfi->width * sizeof(uint16_t));
if (y >= gfi->top && y < gfi->top + gfi->height) {
uint16_t *xoutd = outd + gfi->left - lf;
const uint8_t *ind = gfi->img[y - gfi->top];
for (x = 0; x < width; ++x, ++ind, ++xoutd)
if (map[*ind] != TRANSP)
*xoutd = map[*ind];
}
if (!any_change && memcmp(line, outd, (rt - lf) * sizeof(uint16_t)) != 0)
any_change = 1;
}
}
Gif_ReleaseUncompressedImage(gfi);
Gif_ReleaseCompressedImage(gfi);
/* switch 'glast' with 'scratch' if necessary */
if (gfi->disposal == GIF_DISPOSAL_PREVIOUS) {
uint16_t *x = scratch;
scratch = glast[is_second];
glast[is_second] = x;
}
return any_change;
}
static int
initialize_optimizer(Gif_Stream *gfs)
{
int i;
unsigned screen_size;
if (gfs->nimages < 1)
return 0;
/* combine colormaps */
all_colormap = Gif_NewFullColormap(1, 384);
all_colormap->col[0].gfc_red = 255;
all_colormap->col[0].gfc_green = 255;
all_colormap->col[0].gfc_blue = 255;
in_global_map = gfs->global;
if (!in_global_map) {
Gif_Color *col;
in_global_map = Gif_NewFullColormap(256, 256);
col = in_global_map->col;
for (i = 0; i < 256; i++, col++)
col->gfc_red = col->gfc_green = col->gfc_blue = i;
}
{
int any_globals = 0;
int first_transparent = -1;
for (i = 0; i < gfs->nimages; i++) {
Gif_Image *gfi = gfs->images[i];
if (gfi->local)
colormap_combine(all_colormap, gfi->local);
else
any_globals = 1;
if (gfi->transparent >= 0 && first_transparent < 0)
first_transparent = i;
}
if (any_globals)
colormap_combine(all_colormap, in_global_map);
/* try and maintain transparency's pixel value */
if (first_transparent >= 0) {
Gif_Image *gfi = gfs->images[first_transparent];
Gif_Colormap *gfcm = gfi->local ? gfi->local : gfs->global;
all_colormap->col[TRANSP] = gfcm->col[gfi->transparent];
}
}
/* find screen_width and screen_height, and clip all images to screen */
Gif_CalculateScreenSize(gfs, 0);
screen_width = gfs->screen_width;
screen_height = gfs->screen_height;
for (i = 0; i < gfs->nimages; i++)
Gif_ClipImage(gfs->images[i], 0, 0, screen_width, screen_height);
/* create data arrays */
screen_size = (unsigned) screen_width * (unsigned) screen_height;
last_data = Gif_NewArray(uint16_t, screen_size);
this_data = Gif_NewArray(uint16_t, screen_size);
/* set up colormaps */
gif_color_count = 2;
while (gif_color_count < gfs->global->ncol && gif_color_count < 256)
gif_color_count *= 2;
/* choose background */
if (gfs->images[0]->transparent < 0
&& gfs->background < in_global_map->ncol)
background = in_global_map->col[gfs->background].pixel;
else
background = TRANSP;
return 1;
}
