[gtk+/wip/baedert/gl: 85/90] gl renderer: Fix shadow shader

[Timm Bäder <baedert src gnome org>]

commit 9c67d7d4490ad284cc8a060604f588f41b55ab49
Author: Timm Bäder <mail baedert org>
Date:   Wed Dec 6 17:24:58 2017 +0100

    gl renderer: Fix shadow shader
    
    We need to take the alpha of the shadow color into account as well.

 gsk/resources/glsl/shadow.fs.glsl |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gsk/resources/glsl/shadow.fs.glsl b/gsk/resources/glsl/shadow.fs.glsl
index 3426ba3..f3535f1 100644
--- a/gsk/resources/glsl/shadow.fs.glsl
+++ b/gsk/resources/glsl/shadow.fs.glsl
@@ -7,7 +7,7 @@ void main() {
   // pre-multiply
   color.rgb *= color.a;
 
-  color = vec4(u_color.rgb * diffuse.a, diffuse.a);
+  color = vec4(u_color.rgb * diffuse.a, diffuse.a * color.a);
 
   setOutputColor(color);
 }