From: Christoph M. Becker <cmbecker69@gmx.de>
Date: Sun, 2 Oct 2016 17:06:59 +0000 (+0200)
Subject: Add support for gdEffectMultiply
X-Git-Tag: php-7.2.0alpha1~1217
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=82a8e57f37b9f28357c9ab9fc3df88bafd46ef62;p=php

Add support for gdEffectMultiply

gdLayerMultiply() has been introduced in libgd 2.1.1, and as such would have
been already available for imagelayereffect() with a system libgd. We port
the respective code to the bundled libgd, and also make IMG_EFFECT_MULTIPLY
available to userland.
---

diff --git a/UPGRADING b/UPGRADING
index 055b313974..38250ed303 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -112,6 +112,9 @@ PHP 7.2 UPGRADE NOTES
 10. New Global Constants
 ========================================
 
+- GD:
+  . IMG_EFFECT_MULTIPLY
+
 - Standard:
   . PASSWORD_ARGON2_DEFAULT_MEMORY_COST
   . PASSWORD_ARGON2_DEFAULT_TIME_COST
diff --git a/ext/gd/gd.c b/ext/gd/gd.c
index 6ff2a1c940..f8569779ba 100644
--- a/ext/gd/gd.c
+++ b/ext/gd/gd.c
@@ -1098,6 +1098,9 @@ PHP_MINIT_FUNCTION(gd)
 	REGISTER_LONG_CONSTANT("IMG_EFFECT_ALPHABLEND", gdEffectAlphaBlend, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("IMG_EFFECT_NORMAL", gdEffectNormal, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("IMG_EFFECT_OVERLAY", gdEffectOverlay, CONST_CS | CONST_PERSISTENT);
+#ifdef gdEffectMultiply
+	REGISTER_LONG_CONSTANT("IMG_EFFECT_MULTIPLY", gdEffectMultiply, CONST_CS | CONST_PERSISTENT);
+#endif
 
 	REGISTER_LONG_CONSTANT("IMG_CROP_DEFAULT", GD_CROP_DEFAULT, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("IMG_CROP_TRANSPARENT", GD_CROP_TRANSPARENT, CONST_CS | CONST_PERSISTENT);
diff --git a/ext/gd/libgd/gd.c b/ext/gd/libgd/gd.c
index 5c3593ed1b..afa8e287cc 100644
--- a/ext/gd/libgd/gd.c
+++ b/ext/gd/libgd/gd.c
@@ -93,7 +93,6 @@ extern int gdSinT[];
 
 static void gdImageBrushApply(gdImagePtr im, int x, int y);
 static void gdImageTileApply(gdImagePtr im, int x, int y);
-static int gdLayerOverlay(int dst, int src);
 static int gdAlphaOverlayColor(int src, int dst, int max);
 int gdImageGetTrueColorPixel(gdImagePtr im, int x, int y);
 
@@ -756,14 +755,15 @@ void gdImageSetPixel (gdImagePtr im, int x, int y, int color)
 							im->tpixels[y][x] = color;
 							break;
 						case gdEffectAlphaBlend:
-							im->tpixels[y][x] = gdAlphaBlend(im->tpixels[y][x], color);
-							break;
 						case gdEffectNormal:
 							im->tpixels[y][x] = gdAlphaBlend(im->tpixels[y][x], color);
 							break;
 						case gdEffectOverlay :
 							im->tpixels[y][x] = gdLayerOverlay(im->tpixels[y][x], color);
 							break;
+						case gdEffectMultiply :
+							im->tpixels[y][x] = gdLayerMultiply(im->tpixels[y][x], color);
+							break;
 					}
 				} else {
 					im->pixels[y][x] = color;
@@ -2951,7 +2951,7 @@ void gdImageSaveAlpha (gdImagePtr im, int saveAlphaArg)
 	im->saveAlphaFlag = saveAlphaArg;
 }
 
-static int gdLayerOverlay (int dst, int src)
+int gdLayerOverlay (int dst, int src)
 {
 	int a1, a2;
 	a1 = gdAlphaMax - gdTrueColorGetAlpha(dst);
@@ -2984,6 +2984,28 @@ static int gdAlphaOverlayColor (int src, int dst, int max )
 	}
 }
 
+int gdLayerMultiply (int dst, int src)
+{
+	int a1, a2, r1, r2, g1, g2, b1, b2;
+	a1 = gdAlphaMax - gdTrueColorGetAlpha(src);
+	a2 = gdAlphaMax - gdTrueColorGetAlpha(dst);
+
+	r1 = gdRedMax - (a1 * (gdRedMax - gdTrueColorGetRed(src))) / gdAlphaMax;
+	r2 = gdRedMax - (a2 * (gdRedMax - gdTrueColorGetRed(dst))) / gdAlphaMax;
+	g1 = gdGreenMax - (a1 * (gdGreenMax - gdTrueColorGetGreen(src))) / gdAlphaMax;
+	g2 = gdGreenMax - (a2 * (gdGreenMax - gdTrueColorGetGreen(dst))) / gdAlphaMax;
+	b1 = gdBlueMax - (a1 * (gdBlueMax - gdTrueColorGetBlue(src))) / gdAlphaMax;
+	b2 = gdBlueMax - (a2 * (gdBlueMax - gdTrueColorGetBlue(dst))) / gdAlphaMax ;
+
+	a1 = gdAlphaMax - a1;
+	a2 = gdAlphaMax - a2;
+	return ( ((a1*a2/gdAlphaMax) << 24) +
+			 ((r1*r2/gdRedMax) << 16) +
+			 ((g1*g2/gdGreenMax) << 8) +
+			 ((b1*b2/gdBlueMax))
+		);
+}
+
 void gdImageSetClip (gdImagePtr im, int x1, int y1, int x2, int y2)
 {
 	if (x1 < 0) {
diff --git a/ext/gd/libgd/gd.h b/ext/gd/libgd/gd.h
index 12832ded34..4b6f86e28c 100644
--- a/ext/gd/libgd/gd.h
+++ b/ext/gd/libgd/gd.h
@@ -92,6 +92,7 @@ void php_gd_error(const char *format, ...);
 #define gdEffectAlphaBlend 1
 #define gdEffectNormal 2
 #define gdEffectOverlay 3
+#define gdEffectMultiply 4
 
 #define GD_TRUE 1
 #define GD_FALSE 0
@@ -104,6 +105,8 @@ void php_gd_error(const char *format, ...);
 	The resulting color is opaque. */
 
 int gdAlphaBlend(int dest, int src);
+int gdLayerOverlay(int dst, int src);
+int gdLayerMultiply(int dest, int src);
 
 /**
  * Group: Transform