From 2d537df252bce2e8d80237f20d7ee86b963e9bb9 Mon Sep 17 00:00:00 2001
From: Georg Lehmann <dadschoorse@gmail.com>
Date: Sat, 12 Feb 2022 17:24:07 +0100
Subject: [PATCH] rendervulkan: Don't calculate a garbage alpha value.

---
 src/shaders/cs_composite_blit.comp | 9 +++++----
 src/shaders/cs_composite_rcas.comp | 4 +---
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/shaders/cs_composite_blit.comp b/src/shaders/cs_composite_blit.comp
index f07fc01..1a83186 100644
--- a/src/shaders/cs_composite_blit.comp
+++ b/src/shaders/cs_composite_blit.comp
@@ -35,10 +35,10 @@ void main() {
         return;
 
     vec2 uv = vec2(coord);
-    vec4 outputValue = vec4(0.0f);
+    vec3 outputValue = vec3(0.0f);
 
     if (c_layerCount > 0)
-        outputValue = sampleLayer(0, uv) * u_opacity[0];
+        outputValue = sampleLayer(0, uv).rgb * u_opacity[0];
 
     for (int i = 1; i < c_layerCount; i++) {
         vec4 layerColor = sampleLayer(i, uv);
@@ -49,10 +49,11 @@ void main() {
         // For the other side of things, we need to multiply by (1.0f - (layerColor.a * opacity))
         float opacity = u_opacity[i];
         float layerAlpha = opacity * layerColor.a;
-        outputValue = layerColor * opacity + outputValue * (1.0f - layerAlpha);
+        outputValue = layerColor.rgb * opacity + outputValue * (1.0f - layerAlpha);
     }
 
-    imageStore(dst, ivec2(coord), linearToSrgb(outputValue));
+    outputValue = linearToSrgb(outputValue);
+    imageStore(dst, ivec2(coord), vec4(outputValue, 0));
 
     // Indicator to quickly tell if we're in the compositing path or not.
     if (c_compositing_debug)
diff --git a/src/shaders/cs_composite_rcas.comp b/src/shaders/cs_composite_rcas.comp
index b2db6b6..44afabc 100644
--- a/src/shaders/cs_composite_rcas.comp
+++ b/src/shaders/cs_composite_rcas.comp
@@ -71,9 +71,7 @@ void rcasComposite(uvec2 pos)
         outputValue = linearToSrgb(outputValue);
     }
 
-
-    float undef;
-    imageStore(dst, ivec2(pos), vec4(outputValue, undef));
+    imageStore(dst, ivec2(pos), vec4(outputValue, 0));
 
     if (c_compositing_debug)
         compositing_debug(pos);