From f90e4545c27fa92cc6ba835f80551556929df43d Mon Sep 17 00:00:00 2001
From: Marcus Comstedt
Date: Sun, 1 Feb 2009 14:56:19 +0000
Subject: Merged r36175 from branch-0-13-0:

Fixed alpha blending in the UI dialogs by adding alpha
computation to the blendPixelPtr() function.  To minimize
impact, pre-multiplied alpha is assumed, meaning that the
blending of the R, G and B components is the same both
with and without hardware alpha.

svn-id: r36177
---
 graphics/VectorRendererSpec.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'graphics/VectorRendererSpec.cpp')

diff --git a/graphics/VectorRendererSpec.cpp b/graphics/VectorRendererSpec.cpp
index 37281839cb..ac21203da1 100644
--- a/graphics/VectorRendererSpec.cpp
+++ b/graphics/VectorRendererSpec.cpp
@@ -403,7 +403,10 @@ blendPixelPtr(PixelType *ptr, PixelType color, uint8 alpha)	{
 		(int)(idst & PixelFormat::kGreenMask)) * alpha) >> 8))) |
 		(PixelFormat::kBlueMask & ((idst & PixelFormat::kBlueMask) +
 		((int)(((int)(isrc & PixelFormat::kBlueMask) -
-		(int)(idst & PixelFormat::kBlueMask)) * alpha) >> 8))) );
+		(int)(idst & PixelFormat::kBlueMask)) * alpha) >> 8))) |
+		(PixelFormat::kAlphaMask & ((idst & PixelFormat::kAlphaMask) +
+                ((alpha >> (8 - PixelFormat::kAlphaBits)) << PixelFormat::kAlphaShift) -
+                (((int)(idst & PixelFormat::kAlphaMask) * alpha) >> 8))));
 }
 
 template <typename PixelType, typename PixelFormat>
-- 
cgit v1.2.3