- for (a=0; a<MAX_COLORS; a++)
- {
- XColor xcolor2;
- unsigned short mask;
- int color_found;
- int i;
-
- if (!image->rgb.color_used[a])
- continue;
-
- xcolor.red = *(image->rgb.red + a);
- xcolor.green = *(image->rgb.green + a);
- xcolor.blue = *(image->rgb.blue + a);
-
- /* look if this color already exists in our colormap */
- if (!XAllocColor(display, ximageinfo->cmap, &xcolor))
- {
- if (!private_cmap)
- {
- if (options.verbose)
- Error(ERR_RETURN, "switching to private colormap");
-
- /* we just filled up the default colormap -- get a private one
- which contains all already allocated colors */
-
- global_cmap = XCopyColormapAndFree(display, global_cmap);
- ximageinfo->cmap = global_cmap;
- private_cmap = TRUE;
-
- /* allocate the rest of the color cells read/write */
- global_cmap_index =
- (Pixel *)checked_malloc(sizeof(Pixel) * NOFLASH_COLORS);
- for (i=0; i<NOFLASH_COLORS; i++)
- if (!XAllocColorCells(display, global_cmap, FALSE, NULL, 0,
- global_cmap_index + i, 1))
- break;
- num_cmap_entries = free_cmap_entries = i;
-
- /*
- printf("We've got %d free colormap entries.\n", free_cmap_entries);
- */
-
- /* to minimize colormap flashing, copy default colors and try
- to keep them as near as possible to the old values */
-
- for(i=0; i<num_cmap_entries; i++)
- {
- xcolor2.pixel = *(global_cmap_index + i);
- XQueryColor(display, DefaultColormap(display, screen), &xcolor2);
- XStoreColor(display, global_cmap, &xcolor2);
- xcolor_private[xcolor2.pixel] = xcolor2;
- colorcell_used[xcolor2.pixel] = FALSE;
- }
-
- /* now we have the default colormap private: all colors we
- successfully allocated so far are read-only, which is okay,
- because we don't want to change them anymore -- if we need
- an existing color again, we get it by XAllocColor; all other
- colors are read/write and we can set them by XStoreColor,
- but we will try to overwrite those color cells with our new
- color which are as close as possible to our new color */
- }
-
- /* look for an existing default color close the one we want */
-
- mask = 0xf000;
- color_found = FALSE;
-
- while (!color_found)
- {
- for (i=num_cmap_entries-1; i>=0; i--)
- {
- xcolor2.pixel = *(global_cmap_index + i);
- xcolor2 = xcolor_private[xcolor2.pixel];
-
- if (colorcell_used[xcolor2.pixel])
- continue;
-
- if ((xcolor.red & mask) == (xcolor2.red & mask) &&
- (xcolor.green & mask) == (xcolor2.green & mask) &&
- (xcolor.blue & mask) == (xcolor2.blue & mask))
- {
- /*
- printf("replacing color cell %ld with a close color\n",
- xcolor2.pixel);
- */
- color_found = TRUE;
- break;
- }
- }
-
- if (mask == 0x0000)
- break;
-
- mask = (mask << 1) & 0xffff;
- }
-
- if (!color_found) /* no more free color cells */
- {
- SetError(error, "cannot allocate enough color cells");
- return NULL;
- }
-
- xcolor.pixel = xcolor2.pixel;
- xcolor_private[xcolor.pixel] = xcolor;
- colorcell_used[xcolor.pixel] = TRUE;
- XStoreColor(display, ximageinfo->cmap, &xcolor);
- free_cmap_entries--;
- }
-
- *(ximageinfo->index + a) = xcolor.pixel;
- }