[gtk+] vulkan: Fix border shader to premultiply color

[Benjamin Otte <otte src gnome org>]

commit abc8d61730a657dc8640fc8d40c55d8859e74ae6
Author: Benjamin Otte <otte redhat com>
Date:   Fri Dec 1 14:32:38 2017 +0100

    vulkan: Fix border shader to premultiply color
    
    The inColor wasn't premultiplied, so the resulting colors were wrong
    with translucent borders.

 gsk/resources/vulkan/border-clip-rounded.frag.spv |  Bin 10212 -> 10456 bytes
 gsk/resources/vulkan/border-clip.frag.spv         |  Bin 9560 -> 9804 bytes
 gsk/resources/vulkan/border.frag                  |    2 +-
 gsk/resources/vulkan/border.frag.spv              |  Bin 9560 -> 9804 bytes
 4 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gsk/resources/vulkan/border-clip-rounded.frag.spv 
b/gsk/resources/vulkan/border-clip-rounded.frag.spv
index 690c02b..f60047f 100644
Binary files a/gsk/resources/vulkan/border-clip-rounded.frag.spv and 
b/gsk/resources/vulkan/border-clip-rounded.frag.spv differ
diff --git a/gsk/resources/vulkan/border-clip.frag.spv b/gsk/resources/vulkan/border-clip.frag.spv
index 1a3fda7..2fc1ca1 100644
Binary files a/gsk/resources/vulkan/border-clip.frag.spv and b/gsk/resources/vulkan/border-clip.frag.spv 
differ
diff --git a/gsk/resources/vulkan/border.frag b/gsk/resources/vulkan/border.frag
index 988b1f6..193ccfa 100644
--- a/gsk/resources/vulkan/border.frag
+++ b/gsk/resources/vulkan/border.frag
@@ -20,5 +20,5 @@ void main()
   float alpha = clamp (rounded_rect_coverage (routside, inPos) -
                        rounded_rect_coverage (rinside, inPos),
                        0.0, 1.0);
-  color = clip (inPos, inColor * alpha);
+  color = clip (inPos, vec4(inColor.rgb * inColor.a, inColor.a) * alpha);
 }
diff --git a/gsk/resources/vulkan/border.frag.spv b/gsk/resources/vulkan/border.frag.spv
index 1a3fda7..2fc1ca1 100644
Binary files a/gsk/resources/vulkan/border.frag.spv and b/gsk/resources/vulkan/border.frag.spv differ