From 8668e0b3f625f848ef203de622ca522c34eaf99a Mon Sep 17 00:00:00 2001
From: Nico de Poel <ndepoel@gmail.com>
Date: Mon, 6 Mar 2023 15:13:00 +0100
Subject: [PATCH] Back to basics: allow FSR2 to only output directly to the
 backbuffer

---
 Assets/Scripts/Fsr2Controller.cs | 39 ++++++++++++++------------------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/Assets/Scripts/Fsr2Controller.cs b/Assets/Scripts/Fsr2Controller.cs
index fe047a2..3ffb640 100644
--- a/Assets/Scripts/Fsr2Controller.cs
+++ b/Assets/Scripts/Fsr2Controller.cs
@@ -240,7 +240,18 @@ namespace FidelityFX
             _renderCamera.rect = _originalRect;
             _renderCamera.ResetProjectionMatrix();
 
+            if (dest != null)
+            {
+                Debug.LogError("FSR2 is not set to output directly to the backbuffer");
+                Graphics.Blit(src, dest);
+                enabled = false;
+                return;
+            }
+
             _dispatchCommandBuffer.Clear();
+            
+            // Update the input resource descriptions
+            _dispatchDescription.InputResourceSize = new Vector2Int(src.width, src.height);
 
             if (!enableAutoExposure && exposure != null)
             {
@@ -265,30 +276,14 @@ namespace FidelityFX
                 _dispatchDescription.TransparencyAndComposition = transparencyAndCompositionMask;
             }
 
-            _dispatchDescription.InputResourceSize = new Vector2Int(src.width, src.height);
-
-            if (dest != null)
-            {
-                Debug.Log($"src = {src.width}x{src.height}, dest = {dest.width}x{dest.height}");
-                // We have more image effects lined up after this, so FSR2 can output straight to the intermediate render texture
-                // TODO: we should probably use a shader to include depth & motion vectors into the output, making sure they match the expected output resolution
-                _dispatchCommandBuffer.SetGlobalTexture(Fsr2Pipeline.UavUpscaledOutput, dest);
-            }
-            else
-            {
-                // We are rendering to the backbuffer, so we need a temporary render texture for FSR2 to output to
-                _dispatchCommandBuffer.GetTemporaryRT(Fsr2Pipeline.UavUpscaledOutput, _displaySize.x, _displaySize.y, 0, default, GraphicsFormat.R16G16B16A16_SFloat, 1, true);
-            }
+            // We are rendering to the backbuffer, so we need a temporary render texture for FSR2 to output to
+            _dispatchCommandBuffer.GetTemporaryRT(Fsr2Pipeline.UavUpscaledOutput, _displaySize.x, _displaySize.y, 0, default, GraphicsFormat.R16G16B16A16_SFloat, 1, true);
 
             _context.Dispatch(_dispatchDescription, _dispatchCommandBuffer);
 
-            // Output upscaled image to screen
-            // TODO: if `dest` is null, we likely don't care about the depth & motion vectors anymore
-            if (dest == null)
-            {
-                _dispatchCommandBuffer.Blit(Fsr2Pipeline.UavUpscaledOutput, dest);
-                _dispatchCommandBuffer.ReleaseTemporaryRT(Fsr2Pipeline.UavUpscaledOutput);
-            }
+            // Output the upscaled image to the backbuffer
+            _dispatchCommandBuffer.Blit(Fsr2Pipeline.UavUpscaledOutput, dest);
+            _dispatchCommandBuffer.ReleaseTemporaryRT(Fsr2Pipeline.UavUpscaledOutput);
 
             if (autoGenerateReactiveMask)
             {
@@ -298,7 +293,7 @@ namespace FidelityFX
             Graphics.ExecuteCommandBuffer(_dispatchCommandBuffer);
 
             // Shut up the Unity warning about not writing to the destination texture 
-            Graphics.SetRenderTarget(dest);
+            RenderTexture.active = dest;
         }
     }
 }