--- ../gd-2.0.34-orig/gd.c	Tue Feb  6 16:33:29 2007
+++ gd.c	Sat Aug 18 15:22:53 2007
@@ -2202,6 +2202,66 @@ BGD_DECLARE(void) gdImageCopy (gdImagePt
     }
 }
 
+/*
+ * Blend two true-colour images and optionally adjust the source image's
+ * alpha channel by opacity.  Valid range for opacity is 0 to 100, where 0
+ * means complete transparency (essentially a no-op) and 100 means copy
+ * the source image as-is (essentially calling gdImageCopy()).
+ * If either of the images is not true-colour, or the destination image
+ * does not have its alphaBlendingFlag set, we call gdImageCopyMerge()
+ * and return.
+ */
+BGD_DECLARE(void)
+gdImageBlend(gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX,
+    int srcY, int w, int h, int opacity)
+{
+	int alpha, c, i, x, y;
+	float alpha_adj;
+
+	/* Valid range for opacity is 0 to 100 */
+	if (opacity >= 100) {
+		gdImageCopy(dst, src, dstX, dstY, srcX, srcY, w, h);
+		return;
+	}
+	else if (opacity <= 0)
+		return; /* Complete transparency; i.e., no-op. */
+	/*
+	 * We only handle the case where both images are true-colour and
+	 * destination image has alpha-blending flag set.  Otherwise, we
+	 * simpley call gdImageCopyMerge(...)
+	 */
+	if (!dst->trueColor || !src->trueColor || !dst->alphaBlendingFlag) {
+		gdImageCopyMerge(dst, src, dstX, dstY, srcX, srcY,
+		    w, h, opacity);
+		return;
+	}
+	alpha_adj = (100.0 - opacity) / 100.0;
+	for (y = 0; y < h; ++y) {
+		for (x = 0; x < w; ++x) {
+			c = gdImageGetPixel(src, srcX + x, srcY + y);
+			/*
+			 * I am making an assumption that in true-colour
+			 * images, there is no im->transparent, else we
+			 * could use the following optimization:
+			 *	if (c == src->transparent)
+			 *		continue;
+			 */
+			alpha = (c >> 24) & 0xff;
+			if (alpha == gdAlphaTransparent)
+				continue;
+			/*
+			 * XXX: Can gdAlphaTransparent and gdAlphaMax ever
+			 * be different values?
+			 */
+			alpha += (gdAlphaMax - alpha) * alpha_adj;
+			if (alpha >= gdAlphaMax)
+				continue;
+			c = (c & 0x00ffffff) | (alpha << 24);
+			gdImageSetPixel(dst, dstX + x, dstY + y, c);
+		}
+	}
+}
+
 /* This function is a substitute for real alpha channel operations,
    so it doesn't pay attention to the alpha channel. */
 BGD_DECLARE(void) gdImageCopyMerge (gdImagePtr dst, gdImagePtr src, int dstX, int dstY,