BGD_DECLARE(int) gdImageColorReplaceCallback (gdImagePtr im, gdCallbackImageColor callback)
{
	int c, d, n = 0;

	if (!callback) {
		return 0;
	}
	if (im->trueColor) {
		register int x, y;

		for (y = im->cy1; y <= im->cy2; y++) {
			for (x = im->cx1; x <= im->cx2; x++) {
				c = gdImageTrueColorPixel(im, x, y);
				if ( (d = callback(im, c)) != c) {
					gdImageSetPixel(im, x, y, d);
					n++;
				}
			}
		}
	} else { /* palette */
		int *sarr, *darr;
		int k, len = 0;

		sarr = (int *)gdCalloc(im->colorsTotal, sizeof(int));
		if (!sarr) {
			return -1;
		}
		for (c = 0; c < im->colorsTotal; c++) {
			if (!im->open[c]) {
				sarr[len++] = c;
			}
		}
		darr = (int *)gdCalloc(len, sizeof(int));
		if (!darr) {
			gdFree(sarr);
			return -1;
		}
		for (k = 0; k < len; k++) {
			darr[k] = callback(im, sarr[k]);
		}
		n = gdImageColorReplaceArray(im, k, sarr, darr);
		gdFree(darr);
		gdFree(sarr);
	}
	return n;
}
Unknown