From cbe304c3aefd4b409fc01f4e7d393bf1878a0564 Mon Sep 17 00:00:00 2001
From: Eugene Sandulenko
Date: Wed, 8 Sep 2010 11:32:05 +0000
Subject: SWORD25: Implement transparent bg color for images

svn-id: r53336
---
 engines/sword25/gfx/opengl/glimage.cpp | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

(limited to 'engines/sword25/gfx')

diff --git a/engines/sword25/gfx/opengl/glimage.cpp b/engines/sword25/gfx/opengl/glimage.cpp
index 9feeb4e380..31a52fbed7 100644
--- a/engines/sword25/gfx/opengl/glimage.cpp
+++ b/engines/sword25/gfx/opengl/glimage.cpp
@@ -213,13 +213,21 @@ bool GLImage::blit(int posX, int posY, int flipping, Common::Rect *pPartRect, ui
 		img = &srcImage;
 	}
 
-	if ((color & 0xff000000) != 0xff000000) {
-		warning("STUB: Image transparent bg color: %x", color);
-	}
+	int ca = (color >> 24) & 0xff;
 	int cr = (color >> 16) & 0xff;
 	int cg = (color >> 8) & 0xff;
 	int cb = (color >> 0) & 0xff;
 
+	// Check if we need to draw anything at all
+	if (ca == 0)
+		return true;
+
+	if (ca != 255) {
+		cr = cr * ca >> 8;
+		cg = cg * ca >> 8;
+		cb = cb * ca >> 8;
+	}
+
 	// Handle off-screen clipping
 	if (posY < 0) {
 		img->h -= -posY;
-- 
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