Remove separate pass from PostProcess Uber shader

y-Flip is now controlled with a uniform

Author: hkr

PostProcessing/Runtime/PostProcessLayer.cs

@@ -781,6 +781,19 @@ void RenderList(List<SerializedBundleRef> list, PostProcessRenderContext context
             cmd.EndSample(marker);
         }
 
+        void ApplyFlip(PostProcessRenderContext context, MaterialPropertyBlock properties)
+        {
+            if (context.flip && !context.isSceneView)
+                properties.SetVector(ShaderIDs.UVTransform, new Vector4(1.0f, 1.0f, 0.0f, 0.0f));
+            else
+                ApplyDefaultFlip(properties);
+        }
+
+        void ApplyDefaultFlip(MaterialPropertyBlock properties)
+        {
+            properties.SetVector(ShaderIDs.UVTransform, SystemInfo.graphicsUVStartsAtTop ? new Vector4(1.0f, -1.0f, 0.0f, 1.0f) : new Vector4(1.0f, 1.0f, 0.0f, 0.0f));
+        }
+
         int RenderBuiltins(PostProcessRenderContext context, bool isFinalPass, int releaseTargetAfterUse = -1)
         {
             var uberSheet = context.propertySheets.Get(context.resources.shaders.uber);
@@ -833,18 +846,19 @@ int RenderBuiltins(PostProcessRenderContext context, bool isFinalPass, int relea
             if (!breakBeforeColorGrading)
                 RenderEffect<ColorGrading>(context);
 
-            int pass = 0;
-
             if (isFinalPass)
             {
                 uberSheet.EnableKeyword("FINALPASS");
                 dithering.Render(context);
-
-                if (context.flip && !context.isSceneView)
-                    pass = 1;
+                ApplyFlip(context, uberSheet.properties);
+            }
+            else
+            {
+                uberSheet.EnableKeyword("FINALPASS");
+                ApplyDefaultFlip(uberSheet.properties);
             }
 
-            cmd.BlitFullscreenTriangle(context.source, context.destination, uberSheet, pass);
+            cmd.BlitFullscreenTriangle(context.source, context.destination, uberSheet, 0);
 
             context.source = context.destination;
             context.destination = finalDestination;
@@ -901,7 +915,8 @@ void RenderFinalPass(PostProcessRenderContext context, int releaseTargetAfterUse
 
                 dithering.Render(context);
 
-                cmd.BlitFullscreenTriangle(context.source, context.destination, uberSheet, (context.flip && !context.isSceneView) ? 1 : 0);
+                ApplyFlip(context, uberSheet.properties);
+                cmd.BlitFullscreenTriangle(context.source, context.destination, uberSheet, 0);
 
                 if (tempTarget > -1)
                     cmd.ReleaseTemporaryRT(tempTarget);

PostProcessing/Runtime/Utils/ShaderIDs.cs

@@ -146,5 +146,7 @@ static class ShaderIDs
         internal static readonly int VectorscopeBuffer               = Shader.PropertyToID("_VectorscopeBuffer");
 
         internal static readonly int RenderViewportScaleFactor       = Shader.PropertyToID("_RenderViewportScaleFactor");
+
+        internal static readonly int UVTransform                     = Shader.PropertyToID("_UVTransform");
     }
 }

PostProcessing/Shaders/Builtins/Uber.shader

@@ -244,20 +244,11 @@ Shader "Hidden/PostProcessing/Uber"
         {
             HLSLPROGRAM
 
-                #pragma vertex VertDefault
+                #pragma vertex VertUVTransform
                 #pragma fragment FragUber
 
             ENDHLSL
         }
 
-        Pass
-        {
-            HLSLPROGRAM
-
-                #pragma vertex VertDefaultNoFlip
-                #pragma fragment FragUber
-
-            ENDHLSL
-        }
     }
 }

PostProcessing/Shaders/StdLib.hlsl

@@ -282,11 +282,13 @@ VaryingsDefault VertDefault(AttributesDefault v)
     return o;
 }
 
-VaryingsDefault VertDefaultNoFlip(AttributesDefault v)
+float4 _UVTransform; // xy: scale, wz: translate
+
+VaryingsDefault VertUVTransform(AttributesDefault v)
 {
     VaryingsDefault o;
     o.vertex = float4(v.vertex.xy, 0.0, 1.0);
-    o.texcoord = TransformTriangleVertexToUV(v.vertex.xy);
+    o.texcoord = TransformTriangleVertexToUV(v.vertex.xy) * _UVTransform.xy + _UVTransform.zw;
     o.texcoordStereo = TransformStereoScreenSpaceTex(o.texcoord, 1.0);
     return o;
 }