BGD_DECLARE(void) gdImageCopy (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX,
							   int srcY, int w, int h)
{
	int c;
	int x, y;
	int tox, toy;
	int i;
	int colorMap[gdMaxColors];

	if (dst->trueColor) {
		/* 2.0: much easier when the destination is truecolor. */
		/* 2.0.10: needs a transparent-index check that is still valid if
		 *          * the source is not truecolor. Thanks to Frank Warmerdam.
		 */

		if (src->trueColor) {
			for (y = 0; (y < h); y++) {
				for (x = 0; (x < w); x++) {
					int c = gdImageGetTrueColorPixel (src, srcX + x, srcY + y);
					if (c != src->transparent) {
						gdImageSetPixel (dst, dstX + x, dstY + y, c);
					}
				}
			}
		} else {
			/* source is palette based */
			for (y = 0; (y < h); y++) {
				for (x = 0; (x < w); x++) {
					int c = gdImageGetPixel (src, srcX + x, srcY + y);
					if (c != src->transparent) {
						gdImageSetPixel(dst, dstX + x, dstY + y, gdTrueColorAlpha(src->red[c], src->green[c], src->blue[c], src->alpha[c]));
					}
				}
			}
		}
		return;
	}

	for (i = 0; (i < gdMaxColors); i++) {
		colorMap[i] = (-1);
	}
	toy = dstY;
	for (y = srcY; (y < (srcY + h)); y++) {
		tox = dstX;
		for (x = srcX; (x < (srcX + w)); x++) {
			int nc;
			int mapTo;
			c = gdImageGetPixel (src, x, y);
			/* Added 7/24/95: support transparent copies */
			if (gdImageGetTransparent (src) == c) {
				tox++;
				continue;
			}
			/* Have we established a mapping for this color? */
			if (src->trueColor) {
				/* 2.05: remap to the palette available in the
				 destination image. This is slow and
				 works badly, but it beats crashing! Thanks
				 to Padhrig McCarthy. */
				mapTo = gdImageColorResolveAlpha (dst,
				                                  gdTrueColorGetRed (c),
				                                  gdTrueColorGetGreen (c),
				                                  gdTrueColorGetBlue (c),
				                                  gdTrueColorGetAlpha (c));
			} else if (colorMap[c] == (-1)) {
				/* If it's the same image, mapping is trivial */
				if (dst == src) {
					nc = c;
				} else {
					/* Get best match possible. This
					   function never returns error. */
					nc = gdImageColorResolveAlpha (dst,
					                               src->red[c], src->green[c],
					                               src->blue[c], src->alpha[c]);
				}
				colorMap[c] = nc;
				mapTo = colorMap[c];
			} else {
				mapTo = colorMap[c];
			}
			gdImageSetPixel (dst, tox, toy, mapTo);
			tox++;
		}
		toy++;
	}
}
Unknown