[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [42814] trunk/blender/source/blender/nodes /composite/nodes/node_composite_alphaOver.c: patch [#29676] ALPHA OVER: Fix associated alpha over situation to fix [#29675] patch by Troy Sobotka

[Dalai Felinto]

Revision: 42814
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=42814
Author:   dfelinto
Date:     2011-12-21 23:59:57 +0000 (Wed, 21 Dec 2011)
Log Message:
-----------
patch [#29676] ALPHA OVER: Fix associated alpha over situation to fix [#29675] patch by Troy Sobotka
note: if alpha is negative the code will still produce non-optimal results.
This is a separate issue though, the patch fix the premul assumption that
alpha can be zero and rgb still be valid.

Modified Paths:
--------------
    trunk/blender/source/blender/nodes/composite/nodes/node_composite_alphaOver.c

Modified: trunk/blender/source/blender/nodes/composite/nodes/node_composite_alphaOver.c
===================================================================
--- trunk/blender/source/blender/nodes/composite/nodes/node_composite_alphaOver.c	2011-12-21 23:12:16 UTC (rev 42813)
+++ trunk/blender/source/blender/nodes/composite/nodes/node_composite_alphaOver.c	2011-12-21 23:59:57 UTC (rev 42814)
@@ -47,7 +47,8 @@
 static void do_alphaover_premul(bNode *UNUSED(node), float *out, float *src, float *over, float *fac)
 {
 	
-	if(over[3]<=0.0f) {
+	/* Zero alpha values should still permit an add of RGB data */	
+	if(over[3]<0.0f) {
 		copy_v4_v4(out, src);
 	}
 	else if(fac[0]==1.0f && over[3]>=1.0f) {