From 8ca48e06efa6f6c6e94ba5396fb09831de83116f Mon Sep 17 00:00:00 2001
From: Nico de Poel <ndepoel@gmail.com>
Date: Wed, 5 Jul 2023 13:00:12 +0200
Subject: [PATCH] Refactored mipmap bias callbacks such that the render
 pipeline integration does not need to maintain any bias offset state. Added
 NaN/Infinity/Zero checks to the standard mipmap bias callback
 implementations.

---
 Assets/Scripts/Core/Fsr2Callbacks.cs               | 12 +++++++++---
 Assets/Scripts/Fsr2ImageEffect.cs                  | 12 +-----------
 .../Runtime/Effects/SuperResolution.cs             | 14 ++++----------
 .../PostProcessing/Runtime/FSR2/Fsr2Callbacks.cs   | 12 +++++++++---
 4 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/Assets/Scripts/Core/Fsr2Callbacks.cs b/Assets/Scripts/Core/Fsr2Callbacks.cs
index c3c06e1..ad41d98 100644
--- a/Assets/Scripts/Core/Fsr2Callbacks.cs
+++ b/Assets/Scripts/Core/Fsr2Callbacks.cs
@@ -43,7 +43,7 @@ namespace FidelityFX
         /// </summary>
         void ApplyMipmapBias(float biasOffset);
 
-        void UndoMipmapBias(float biasOffset);
+        void UndoMipmapBias();
     }
     
     /// <summary>
@@ -76,6 +76,9 @@ namespace FidelityFX
 
         public virtual void ApplyMipmapBias(float biasOffset)
         {
+            if (float.IsNaN(biasOffset) || float.IsInfinity(biasOffset))
+                return;
+            
             CurrentBiasOffset += biasOffset;
             
             if (Mathf.Approximately(CurrentBiasOffset, 0f))
@@ -92,9 +95,12 @@ namespace FidelityFX
             }
         }
 
-        public virtual void UndoMipmapBias(float biasOffset)
+        public virtual void UndoMipmapBias()
         {
-            ApplyMipmapBias(-biasOffset);
+            if (CurrentBiasOffset == 0f)
+                return;
+
+            ApplyMipmapBias(-CurrentBiasOffset);
         }
     }
 }
diff --git a/Assets/Scripts/Fsr2ImageEffect.cs b/Assets/Scripts/Fsr2ImageEffect.cs
index 4475ebd..7daeb60 100644
--- a/Assets/Scripts/Fsr2ImageEffect.cs
+++ b/Assets/Scripts/Fsr2ImageEffect.cs
@@ -105,7 +105,6 @@ namespace FidelityFX
         private Fsr2Context _context;
         private Vector2Int _maxRenderSize;
         private Vector2Int _displaySize;
-        private float _appliedBiasOffset;
         private bool _resetHistory;
         
         private readonly Fsr2.DispatchDescription _dispatchDescription = new Fsr2.DispatchDescription();
@@ -238,22 +237,13 @@ namespace FidelityFX
             if (!float.IsNaN(biasOffset) && !float.IsInfinity(biasOffset))
             {
                 Callbacks.ApplyMipmapBias(biasOffset);
-                _appliedBiasOffset = biasOffset;
-            }
-            else
-            {
-                _appliedBiasOffset = 0f;
             }
         }
 
         private void UndoMipmapBias()
         {
             // Undo the current mipmap bias offset
-            if (_appliedBiasOffset != 0f && !float.IsNaN(_appliedBiasOffset) && !float.IsInfinity(_appliedBiasOffset))
-            {
-                Callbacks.UndoMipmapBias(_appliedBiasOffset);
-                _appliedBiasOffset = 0f;
-            }
+            Callbacks.UndoMipmapBias();
         }
 
         private void Update()
diff --git a/com.unity.postprocessing/PostProcessing/Runtime/Effects/SuperResolution.cs b/com.unity.postprocessing/PostProcessing/Runtime/Effects/SuperResolution.cs
index a053cc7..1de3b14 100644
--- a/com.unity.postprocessing/PostProcessing/Runtime/Effects/SuperResolution.cs
+++ b/com.unity.postprocessing/PostProcessing/Runtime/Effects/SuperResolution.cs
@@ -110,7 +110,6 @@ namespace UnityEngine.Rendering.PostProcessing
         private bool _resetHistory;
 
         private IFsr2Callbacks _callbacks;
-        private float _appliedBiasOffset;
 
         private readonly Fsr2.DispatchDescription _dispatchDescription = new Fsr2.DispatchDescription();
         private readonly Fsr2.GenerateReactiveDescription _genReactiveDescription = new Fsr2.GenerateReactiveDescription();
@@ -223,11 +222,6 @@ namespace UnityEngine.Rendering.PostProcessing
             if (!float.IsNaN(biasOffset) && !float.IsInfinity(biasOffset))
             {
                 _callbacks.ApplyMipmapBias(biasOffset);
-                _appliedBiasOffset = biasOffset;
-            }
-            else
-            {
-                _appliedBiasOffset = 0f;
             }
         }
         
@@ -239,11 +233,11 @@ namespace UnityEngine.Rendering.PostProcessing
                 _fsrContext = null;
             }
 
-            // Undo the current mipmap bias offset
-            if (_appliedBiasOffset != 0f && !float.IsNaN(_appliedBiasOffset) && !float.IsInfinity(_appliedBiasOffset))
+            if (_callbacks != null)
             {
-                _callbacks.UndoMipmapBias(_appliedBiasOffset);
-                _appliedBiasOffset = 0f;
+                // Undo the current mipmap bias offset
+                _callbacks.UndoMipmapBias();
+                _callbacks = null;
             }
         }
 
diff --git a/com.unity.postprocessing/PostProcessing/Runtime/FSR2/Fsr2Callbacks.cs b/com.unity.postprocessing/PostProcessing/Runtime/FSR2/Fsr2Callbacks.cs
index c3c06e1..ad41d98 100644
--- a/com.unity.postprocessing/PostProcessing/Runtime/FSR2/Fsr2Callbacks.cs
+++ b/com.unity.postprocessing/PostProcessing/Runtime/FSR2/Fsr2Callbacks.cs
@@ -43,7 +43,7 @@ namespace FidelityFX
         /// </summary>
         void ApplyMipmapBias(float biasOffset);
 
-        void UndoMipmapBias(float biasOffset);
+        void UndoMipmapBias();
     }
     
     /// <summary>
@@ -76,6 +76,9 @@ namespace FidelityFX
 
         public virtual void ApplyMipmapBias(float biasOffset)
         {
+            if (float.IsNaN(biasOffset) || float.IsInfinity(biasOffset))
+                return;
+            
             CurrentBiasOffset += biasOffset;
             
             if (Mathf.Approximately(CurrentBiasOffset, 0f))
@@ -92,9 +95,12 @@ namespace FidelityFX
             }
         }
 
-        public virtual void UndoMipmapBias(float biasOffset)
+        public virtual void UndoMipmapBias()
         {
-            ApplyMipmapBias(-biasOffset);
+            if (CurrentBiasOffset == 0f)
+                return;
+
+            ApplyMipmapBias(-CurrentBiasOffset);
         }
     }
 }