Respect output target texture's dimensions when determining render size and rescaling camera viewport.

Assets/Scripts/Fsr2ImageEffect.cs

@@ -103,7 +103,7 @@ namespace FidelityFX
             _renderCamera.depthTextureMode = _originalDepthTextureMode | DepthTextureMode.Depth | DepthTextureMode.MotionVectors;
             
             // Determine the desired rendering and display resolutions
-            _displaySize = new Vector2Int(_renderCamera.pixelWidth, _renderCamera.pixelHeight);
+            _displaySize = GetDisplaySize();
             Fsr2.GetRenderResolutionFromQualityMode(out var renderWidth, out var renderHeight, _displaySize.x, _displaySize.y, qualityMode);
             _renderSize = new Vector2Int(renderWidth, renderHeight);
             
@@ -185,7 +185,8 @@ namespace FidelityFX
 
         private void Update()
         {
-            if (_renderCamera.pixelWidth != _prevDisplaySize.x || _renderCamera.pixelHeight != _prevDisplaySize.y || qualityMode != _prevQualityMode)
+            var displaySize = GetDisplaySize();
+            if (displaySize.x != _prevDisplaySize.x || displaySize.y != _prevDisplaySize.y || qualityMode != _prevQualityMode)
             {
                 // Force all resources to be destroyed and recreated with the new settings
                 OnDisable();
@@ -219,8 +220,8 @@ namespace FidelityFX
             if (_helper == null || !_helper.enabled)
             {
                 // Render to a smaller portion of the screen by manipulating the camera's viewport rect
-                _renderCamera.aspect = (_renderCamera.pixelWidth * _originalRect.width) / (_renderCamera.pixelHeight * _originalRect.height);
-                _renderCamera.rect = new Rect(0, 0, _originalRect.width * _renderSize.x / _displaySize.x, _originalRect.height * _renderSize.y / _displaySize.y);
+                _renderCamera.aspect = (_displaySize.x * _originalRect.width) / (_displaySize.y * _originalRect.height);
+                _renderCamera.rect = new Rect(0, 0, _originalRect.width * _renderSize.x / _renderCamera.pixelWidth, _originalRect.height * _renderSize.y / _renderCamera.pixelHeight);
             }
 
             // Set up the parameters to auto-generate a reactive mask
@@ -322,13 +323,12 @@ namespace FidelityFX
             _context.Dispatch(_dispatchDescription, _dispatchCommandBuffer);
 
             // Output the upscaled image
-            if (_originalRenderTarget != null || outputColorDepth != null)
+            var outputTexture = GetOutputTexture();
+            if (outputTexture != null)
             {
-                var targetTexture = outputColorDepth != null ? outputColorDepth : _originalRenderTarget;
-                
                 // Output to the camera target texture, passing through depth and motion vectors
                 _dispatchCommandBuffer.SetGlobalTexture("_DepthTex", BuiltinRenderTextureType.CameraTarget, RenderTextureSubElement.Depth);
-                _dispatchCommandBuffer.Blit(Fsr2ShaderIDs.UavUpscaledOutput, targetTexture, _copyWithDepthMaterial);
+                _dispatchCommandBuffer.Blit(Fsr2ShaderIDs.UavUpscaledOutput, outputTexture, _copyWithDepthMaterial);
                 if (outputMotionVectors != null)
                     _dispatchCommandBuffer.Blit(BuiltinRenderTextureType.MotionVectors, outputMotionVectors);
             }
@@ -350,5 +350,16 @@ namespace FidelityFX
             // Shut up the Unity warning about not writing to the destination texture 
             RenderTexture.active = dest;
         }
+        
+        private RenderTexture GetOutputTexture() => outputColorDepth != null ? outputColorDepth : _originalRenderTarget;
+
+        private Vector2Int GetDisplaySize()
+        {
+            var outputTexture = GetOutputTexture();
+            if (outputTexture != null)
+                return new Vector2Int(outputTexture.width, outputTexture.height);
+            
+            return new Vector2Int(_renderCamera.pixelWidth, _renderCamera.pixelHeight);
+        }
     }
 }