From: Christoph M. Becker <cmbecker69@gmx.de>
Date: Thu, 15 Sep 2016 11:18:54 +0000 (+0200)
Subject: Port optimization from external libgd
X-Git-Tag: php-7.2.0alpha1~1254
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ba2b50d097569381f98b306c932e240cd50cbb3d;p=php

Port optimization from external libgd

The functionality is identical, but we save two function calls for partially
transparent pixels.
---

diff --git a/ext/gd/libgd/gdft.c b/ext/gd/libgd/gdft.c
index 6de314e971..f91fcf738c 100644
--- a/ext/gd/libgd/gdft.c
+++ b/ext/gd/libgd/gdft.c
@@ -626,6 +626,7 @@ static char * gdft_draw_bitmap (gdCache_head_t *tc_cache, gdImage * im, int fg,
 {
 	unsigned char *pixel = NULL;
 	int *tpixel = NULL;
+	int opixel;
 	int x, y, row, col, pc, pcr;
 
 	tweencolor_t *tc_elem;
@@ -683,7 +684,13 @@ static char * gdft_draw_bitmap (gdCache_head_t *tc_cache, gdImage * im, int fg,
 					}
 				} else {
 					if (im->alphaBlendingFlag) {
-						*tpixel = gdAlphaBlend(*tpixel, (level << 24) + (fg & 0xFFFFFF));
+						opixel = *tpixel;
+						if (gdTrueColorGetAlpha(opixel) != gdAlphaTransparent) {
+							*tpixel = gdAlphaBlend (opixel,
+							                        (level << 24) + (fg & 0xFFFFFF));
+						} else {
+							*tpixel = (level << 24) + (fg & 0xFFFFFF);
+						}
 					} else {
 						*tpixel = (level << 24) + (fg & 0xFFFFFF);
 					}