From 6fb3946c51d6bb4f6ec80016978689147b197ca2 Mon Sep 17 00:00:00 2001
From: Julien Jorge <julien.jorge@stuff-o-matic.com>
Date: Mon, 20 Jun 2016 17:25:31 +0200
Subject: [PATCH] Add a config option to enable or disable the premultiplied
 alpha code.

---
 cocos/base/ccConfig.h      | 8 ++++++++
 cocos/platform/CCImage.cpp | 5 +++++
 2 files changed, 13 insertions(+)

diff --git a/cocos/base/ccConfig.h b/cocos/base/ccConfig.h
index 4a251b7646..a79c1875a6 100644
--- a/cocos/base/ccConfig.h
+++ b/cocos/base/ccConfig.h
@@ -397,4 +397,12 @@ THE SOFTWARE.
 #define CC_FILEUTILS_APPLE_ENABLE_OBJC  1
 #endif
 
+/** @def CC_ENABLE_PREMULTIPLIED_ALPHA
+ * If enabled, all textures will be preprocessed to multiply its rgb components
+ * by its alpha component.
+ */
+#ifndef CC_ENABLE_PREMULTIPLIED_ALPHA
+# define CC_ENABLE_PREMULTIPLIED_ALPHA 1
+#endif
+
 #endif // __CCCONFIG_H__
diff --git a/cocos/platform/CCImage.cpp b/cocos/platform/CCImage.cpp
index ee977724c6..b9806628e4 100644
--- a/cocos/platform/CCImage.cpp
+++ b/cocos/platform/CCImage.cpp
@@ -2451,6 +2451,10 @@ bool Image::saveImageToJPG(const std::string& filePath)
 
 void Image::premultipliedAlpha()
 {
+#if CC_ENABLE_PREMULTIPLIED_ALPHA == 0
+        _hasPremultipliedAlpha = false;
+        return;
+#else
     CCASSERT(_renderFormat == Texture2D::PixelFormat::RGBA8888, "The pixel format should be RGBA8888!");
     
     unsigned int* fourBytes = (unsigned int*)_data;
@@ -2461,6 +2465,7 @@ void Image::premultipliedAlpha()
     }
     
     _hasPremultipliedAlpha = true;
+#endif
 }