From b763d5fffa2f942a6ae3637fab17439dd32dbebc Mon Sep 17 00:00:00 2001
From: Jesse Hall <jessehall@google.com>
Date: Wed, 10 Oct 2012 21:37:22 -0700
Subject: [PATCH] Assume LayerScreenshot has pre-multiplied alpha

Bug: 7300129
Change-Id: Ie9114adc4b5c9a8cc3c65bfe6d9478b2cba4e0d8
---
 services/surfaceflinger/LayerScreenshot.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/services/surfaceflinger/LayerScreenshot.cpp b/services/surfaceflinger/LayerScreenshot.cpp
index 5c18ebd53..1aa8c099d 100644
--- a/services/surfaceflinger/LayerScreenshot.cpp
+++ b/services/surfaceflinger/LayerScreenshot.cpp
@@ -118,21 +118,21 @@ void LayerScreenshot::onDraw(const sp<const DisplayDevice>& hw, const Region& cl
 
         if (s.alpha == 0xFF) {
             glDisable(GL_BLEND);
+            glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
         } else {
             glEnable(GL_BLEND);
-            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+            glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+            glColor4f(alpha, alpha, alpha, alpha);
+            glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
         }
 
         LayerMesh mesh;
         computeGeometry(hw, &mesh);
 
-        glColor4f(0, 0, 0, alpha);
-
         glDisable(GL_TEXTURE_EXTERNAL_OES);
         glEnable(GL_TEXTURE_2D);
 
         glBindTexture(GL_TEXTURE_2D, mTextureName);
-        glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
         glMatrixMode(GL_TEXTURE);
         glLoadIdentity();
         glMatrixMode(GL_MODELVIEW);