-#ifdef DEBUG
- fprintf(stderr, "%s: installing cubic colormap\n", progname);
-#endif /* DEBUG */
-
- XStoreColors (dpy, cmap, colors, cells);
- XSetWindowColormap (dpy, window, cmap);
-
- /* Gag, install the colormap.
- This is definitely right in the `if xscreensaver_window_p' case, since
- it will never get installed otherwise. But, if we don't do it
- unconditionally, then the new colormap won't get installed until the
- window (re-)gains focus. It's generally very antisocial to install
- the colormap of a non-OverrideRedirect window (that task belongs to
- the WM) and if we were being kosher, we would only install this cmap
- if the old cmap was already installed (or perhaps, if the window had
- focus.) But, since this extension only exists on SGIs, and since SGIs
- can handle four colormaps at once, let's go ahead and install it all
- the time, so that even if the window pops up and has never had focus,
- it will still display in the proper colors.
- */
- XInstallColormap (dpy, cmap);
+ {
+ int j;
+ int allocated = 0;
+ int interleave = cells / 8; /* skip around, rather than allocating in
+ order, so that we get better coverage if
+ we can't allocated all of them. */
+ for (j = 0; j < interleave; j++)
+ for (i = 0; i < cells; i += interleave)
+ if (XAllocColor (dpy, cmap, &colors[i + j]))
+ allocated++;
+
+ if (grab_verbose_p)
+ fprintf (stderr, "%s: allocated %d of %d colors for cubic map\n",
+ progname, allocated, cells);
+ }
+}
+
+static unsigned long
+find_closest_pixel (XColor *colors, int ncolors,
+ unsigned long r, unsigned long g, unsigned long b)
+{
+ unsigned long distance = ~0;
+ int i, found = 0;
+
+ if (ncolors == 0)
+ abort();
+ for (i = 0; i < ncolors; i++)
+ {
+ unsigned long d;
+ int rd, gd, bd;
+
+ rd = r - colors[i].red;
+ gd = g - colors[i].green;
+ bd = b - colors[i].blue;
+ if (rd < 0) rd = -rd;
+ if (gd < 0) gd = -gd;
+ if (bd < 0) bd = -bd;
+ d = (rd << 1) + (gd << 2) + bd;
+
+ if (d < distance)
+ {
+ distance = d;
+ found = i;
+ if (distance == 0)
+ break;
+ }
+ }
+
+ return found;
+}
+
+
+void
+remap_image (Screen *screen, Window window, Colormap cmap, XImage *image)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ unsigned long map[4097];
+ int x, y, i;
+ int cells;
+ XColor colors[4097];
+
+ if (image->depth == 8)
+ cells = 256;
+ else if (image->depth == 12)
+ cells = 4096;
+ else
+ abort();
+
+ memset(map, -1, sizeof(*map));
+ memset(colors, -1, sizeof(*colors));
+
+ for (i = 0; i < cells; i++)
+ colors[i].pixel = i;
+ XQueryColors (dpy, cmap, colors, cells);
+
+ if (grab_verbose_p)
+ fprintf(stderr, "%s: building table for %d bit image\n",
+ progname, image->depth);
+
+ for (i = 0; i < cells; i++)
+ {
+ unsigned short r, g, b;
+
+ if (cells == 256)
+ {
+ /* "RRR GGG BB" In an 8 bit map. Convert that to
+ "RRR RRR RR" "GGG GGG GG" "BB BB BB BB" to give
+ an even spread. */
+ r = (i & 0x07);
+ g = (i & 0x38) >> 3;
+ b = (i & 0xC0) >> 6;
+
+ r = ((r << 13) | (r << 10) | (r << 7) | (r << 4) | (r << 1));
+ g = ((g << 13) | (g << 10) | (g << 7) | (g << 4) | (g << 1));
+ b = ((b << 14) | (b << 12) | (b << 10) | (b << 8) |
+ (b << 6) | (b << 4) | (b << 2) | b);
+ }
+ else
+ {
+ /* "RRRR GGGG BBBB" In a 12 bit map. Convert that to
+ "RRRR RRRR" "GGGG GGGG" "BBBB BBBB" to give an even
+ spread. */
+ r = (i & 0x00F);
+ g = (i & 0x0F0) >> 4;
+ b = (i & 0xF00) >> 8;
+
+ r = (r << 12) | (r << 8) | (r << 4) | r;
+ g = (g << 12) | (g << 8) | (g << 4) | g;
+ b = (b << 12) | (b << 8) | (b << 4) | b;
+ }
+
+ map[i] = find_closest_pixel (colors, cells, r, g, b);
+ }
+
+ if (grab_verbose_p)
+ fprintf(stderr, "%s: remapping colors in %d bit image\n",
+ progname, image->depth);
+
+ for (y = 0; y < image->height; y++)
+ for (x = 0; x < image->width; x++)
+ {
+ unsigned long pixel = XGetPixel(image, x, y);
+ if (pixel >= cells) abort();
+ XPutPixel(image, x, y, map[pixel]);
+ }