From aa46d166990b6b9890900c208ef9ec7cfb927181 Mon Sep 17 00:00:00 2001
From: Olivier Prat <olivier@zvork.fr>
Date: Thu, 22 Feb 2018 10:09:03 +0100
Subject: [PATCH] A bit of cleanup in TAA shaders

---
 libraries/render-utils/src/taa.slh       | 17 +++++++++++++----
 libraries/render-utils/src/taa_blend.slf |  1 +
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/libraries/render-utils/src/taa.slh b/libraries/render-utils/src/taa.slh
index 3b3e275da1..bca0356949 100644
--- a/libraries/render-utils/src/taa.slh
+++ b/libraries/render-utils/src/taa.slh
@@ -38,6 +38,10 @@ layout(std140) uniform taaParamsBuffer {
 
 #define GET_BIT(bitfield, bitIndex) bool((bitfield) & (1 << (bitIndex)))
 
+bool taa_isDebugEnabled() {
+    return GET_BIT(params.flags.x, 0);
+}
+
 bool taa_showDebugCursor() {
     return GET_BIT(params.flags.x, 1);
 }
@@ -247,14 +251,19 @@ vec2 taa_fromEyeUVToFragUV(vec2 eyeUV, int stereoSide) {
     return fragUV;
 }
 
-vec2 taa_fetchSourceAndHistory(vec2 fragUV, vec2 fragVelocity, out vec3 sourceColor, out vec3 historyColor) {
-    sourceColor = taa_fetchSourceMap(fragUV).xyz;
+vec2 taa_computePrevFragAndEyeUV(vec2 fragUV, vec2 fragVelocity, out vec2 prevEyeUV) {
     int stereoSide = 0;
     vec2 eyeUV = taa_fromFragUVToEyeUVAndSide(fragUV, stereoSide);
-    vec2 prevEyeUV = eyeUV - fragVelocity;
+    prevEyeUV = eyeUV - fragVelocity;
+    return taa_fromEyeUVToFragUV(prevEyeUV, stereoSide);
+}
+
+vec2 taa_fetchSourceAndHistory(vec2 fragUV, vec2 fragVelocity, out vec3 sourceColor, out vec3 historyColor) {
+    vec2 prevEyeUV;
+    vec2 prevFragUV = taa_computePrevFragAndEyeUV(fragUV, fragVelocity, prevEyeUV);
+    sourceColor = taa_fetchSourceMap(fragUV).xyz;
 
     historyColor = sourceColor;
-    vec2 prevFragUV = taa_fromEyeUVToFragUV(prevEyeUV, stereoSide);
     if (!(any(lessThan(prevEyeUV, vec2(0.0))) || any(greaterThan(prevEyeUV, vec2(1.0))))) {
         historyColor = taa_fetchHistoryMap(prevFragUV).xyz;
     }
diff --git a/libraries/render-utils/src/taa_blend.slf b/libraries/render-utils/src/taa_blend.slf
index bb81f4989f..aca934ca71 100644
--- a/libraries/render-utils/src/taa_blend.slf
+++ b/libraries/render-utils/src/taa_blend.slf
@@ -145,6 +145,7 @@ void main(void) {
     if (!(any(lessThan(prevTexCoord, vec2(0.0))) || any(greaterThan(prevTexCoord, vec2(1.0))))) {
         prevColor = texture(historyMap, prevTexCoord).xyz;
     }
+
     outFragColor.xyz = mix(prevColor, vec3(1,0,1), clamp(distance(prevColor, nextColor) - 0.01, 0, 1));
 
     if (pixVelocityLength > params.debugShowVelocityThreshold) {