[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [54638] trunk/blender/source/blender/gpu/ intern/gpu_draw.c: Fix wrong alpha channel for OpenGL render results with transparent textures or

[Brecht Van Lommel]

Revision: 54638
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=54638
Author:   blendix
Date:     2013-02-18 17:39:44 +0000 (Mon, 18 Feb 2013)
Log Message:
-----------
Fix wrong alpha channel for OpenGL render results with transparent textures or
materials, the typical glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); blend
function does not give correct destination alpha.

Modified Paths:
--------------
    trunk/blender/source/blender/gpu/intern/gpu_draw.c

Modified: trunk/blender/source/blender/gpu/intern/gpu_draw.c
===================================================================
--- trunk/blender/source/blender/gpu/intern/gpu_draw.c	2013-02-18 16:35:13 UTC (rev 54637)
+++ trunk/blender/source/blender/gpu/intern/gpu_draw.c	2013-02-18 17:39:44 UTC (rev 54638)
@@ -395,7 +395,12 @@
 	}
 	else if (ELEM(alphablend, GPU_BLEND_ALPHA, GPU_BLEND_ALPHA_SORT)) {
 		glEnable(GL_BLEND);
-		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+		/* for OpenGL render we use the alpha channel, this makes alpha blend correct */
+		if (GLEW_VERSION_1_4)
+			glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+		else
+			glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 		
 		/* if U.glalphaclip == 1.0, some cards go bonkers...
 		 * turn off alpha test in this case */