void image_add_thumbnail_frame(GdkPixbuf *img)
{
guint32 outline = IMAGEFU_COLOR(0xFF, 0x55, 0x55, 0x55);
guint32 transparent = IMAGEFU_COLOR(0x00, 0xFF, 0xFF, 0xFF);
guint32 shadow = IMAGEFU_COLOR(0x22, 0x00, 0x00, 0x00);
int width = gdk_pixbuf_get_width(img);
int height = gdk_pixbuf_get_height(img);
if (width <= 2)
return;
if (height <= 2)
return;
image_draw_rect_outline(img, 0, 0, width, height, transparent);
image_draw_rect_outline(img, 1, 1, width-2, height-2, outline);
image_draw_hline(img, 2, height-1, width-2, shadow);
image_draw_vline(img, width-1, 2, height-2, shadow);
}
static void
histogram_imager_generate_color_table (HistogramImager *self, gboolean force)
{
/* Regenerate the contents of the color mapping table, a mapping from all
* possible histogram values to the corresponding ARGB color, in the current image.
*/
guint count;
float pixel_scale = histogram_imager_get_pixel_scale (self);
gulong usable_density = histogram_imager_get_max_usable_density (self);
float luma;
double one_over_gamma = 1/self->gamma;
float distance = 0;
gulong color_table_size;
struct {
int r, g, b, a;
} current, previous;
/* Our actual color table size should be either the maximum
* usable density, or our histogram's current peak density,
* whichever is smaller.
*/
if (usable_density > self->peak_density)
usable_density = self->peak_density;
/* If the table is already the right size and we aren't being
* forced to regenerate it, stop now.
*/
color_table_size = usable_density + 1;
if ((!force) && self->color_table.filled_size == color_table_size)
return;
/* Make sure our table is appropriately sized */
histogram_imager_resize_color_table (self, color_table_size);
/* Generate one color for every currently-possible count value that
* doesn't fully saturate our image, as determined by histogram_imager_get_max_usable_density
*/
for (count=0; count < self->color_table.filled_size; count++) {
/* Scale and gamma-correct */
luma = count * pixel_scale;
luma = pow(luma, one_over_gamma);
/* Optionally clamp before interpolating */
if (self->clamped && luma > 1)
luma = 1;
/* Linearly interpolate between fgcolor and bgcolor */
current.r = ((int)(self->bgcolor.red * (1-luma) + self->fgcolor.red * luma)) >> 8;
current.g = ((int)(self->bgcolor.green * (1-luma) + self->fgcolor.green * luma)) >> 8;
current.b = ((int)(self->bgcolor.blue * (1-luma) + self->fgcolor.blue * luma)) >> 8;
current.a = ((int)(self->bgalpha * (1-luma) + self->fgalpha * luma)) >> 8;
/* Always clamp color components */
if (current.r<0) current.r = 0; if (current.r>255) current.r = 255;
if (current.g<0) current.g = 0; if (current.g>255) current.g = 255;
if (current.b<0) current.b = 0; if (current.b>255) current.b = 255;
if (current.a<0) current.a = 0; if (current.a>255) current.a = 255;
/* Colors are always ARGB order in little endian */
self->color_table.table[count] = IMAGEFU_COLOR(current.a, current.r, current.g, current.b);
/* Update our elapsed distance */
if (count > 0) {
distance += sqrt( (current.r - previous.r) * (current.r - previous.r) +
(current.g - previous.g) * (current.g - previous.g) +
(current.b - previous.b) * (current.b - previous.b) +
(current.a - previous.a) * (current.a - previous.a) );
}
previous = current;
/* "distance" is the distance we've traveled from the background to this
* point in the color hypercube. Our quality metric is based on the number
* of histogram samples per color cube samples: our 'quality' table stores
* the current count divided by its corresponding distance.
*/
if (distance > 0) {
self->color_table.quality[count] = count / distance;
}
else {
/* We shouldn't ever use quality entries where the distance
* is zero- this value is pretty arbitrary.
*/
self->color_table.quality[count] = 0;
}
}
}
