From 922e89f9fe8a320af553909fc735fd1ae62e9766 Mon Sep 17 00:00:00 2001
From: Nico de Poel <ndepoel@gmail.com>
Date: Sat, 14 Dec 2024 13:33:09 +0100
Subject: [PATCH] Updated shaders to FSR 3.1.3: - Color clamp now uses
 ellipsoid instead of AABB to help with ghosting streaks - Moved velocity
 factor to a different section of the accumulate pass

---
 .../ffx_fsr3upscaler_accumulate.h             | 23 +++++++++----------
 .../ffx_fsr3upscaler_callbacks_hlsl.h         |  2 +-
 .../fsr3upscaler/ffx_fsr3upscaler_common.h    |  2 +-
 3 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_accumulate.h b/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_accumulate.h
index 2cba17c..084d4d3 100644
--- a/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_accumulate.h
+++ b/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_accumulate.h
@@ -52,21 +52,20 @@ void RectifyHistory(
     const FfxFloat32 fReactiveFactor        = ffxPow(params.fReactiveMask, 1.0f / 2.0f);
     const FfxFloat32 fShadingChangeFactor   = params.fShadingChange;
     const FfxFloat32 fBoxScaleT             = ffxMax(fVecolityFactor, ffxMax(fDistanceFactor, ffxMax(fAccumulationFactor, ffxMax(fReactiveFactor, fShadingChangeFactor))));
+    
+    const FfxFloat32   fBoxScale     = ffxLerp(3.0f, 1.0f, fBoxScaleT);
+    const FfxFloat32x3 fScaledBoxVec = data.clippingBox.boxVec * FfxFloat32x3(1.7f, 1.0f, 1.0f) * fBoxScale;
 
-    const FfxFloat32 fBoxScale = ffxLerp(3.0f, 1.0f, fBoxScaleT);
-
-    const FfxFloat32x3 fScaledBoxVec = data.clippingBox.boxVec * fBoxScale;
-    const FfxFloat32x3 fBoxMin = data.clippingBox.boxCenter - fScaledBoxVec;
-    const FfxFloat32x3 fBoxMax = data.clippingBox.boxCenter + fScaledBoxVec;
-
-    if (any(FFX_GREATER_THAN(fBoxMin, data.fHistoryColor)) || any(FFX_GREATER_THAN(data.fHistoryColor, fBoxMax))) {
-
-        const FfxFloat32x3 fClampedHistoryColor = clamp(data.fHistoryColor, fBoxMin, fBoxMax);
+    const FfxFloat32x3 fClampedScaledBoxVec     = ffxMax(fScaledBoxVec, FfxFloat32x3(1.193e-7f, 1.193e-7f, 1.193e-7f));
+    const FfxFloat32x3 fTransformedHistoryColor = (data.fHistoryColor - data.clippingBox.boxCenter) / fClampedScaledBoxVec;
 
-        const FfxFloat32 fHistoryContribution = ffxMax(params.fLumaInstabilityFactor, data.fLockContributionThisFrame) * params.fAccumulation * (1 - params.fDisocclusion);
+    if (length(fTransformedHistoryColor)>1.f) {
+        const FfxFloat32x3 fClampedHistoryColor = normalize(fTransformedHistoryColor);
+        const FfxFloat32x3 fFinalClampedHistoryColor = (fClampedHistoryColor * fScaledBoxVec) + data.clippingBox.boxCenter;
 
         // Scale history color using rectification info, also using accumulation mask to avoid potential invalid color protection
-        data.fHistoryColor = ffxLerp(fClampedHistoryColor, data.fHistoryColor, ffxSaturate(fHistoryContribution));
+        const FfxFloat32 fHistoryContribution = ffxMax(params.fLumaInstabilityFactor, data.fLockContributionThisFrame) * params.fAccumulation * (1 - params.fDisocclusion);
+        data.fHistoryColor = ffxLerp(fFinalClampedHistoryColor, data.fHistoryColor, ffxSaturate(fHistoryContribution));
     }
 }
 
@@ -97,7 +96,7 @@ void ComputeBaseAccumulationWeight(const AccumulationPassCommonParams params, FF
 {
     FfxFloat32 fBaseAccumulation = params.fAccumulation;
 
-    fBaseAccumulation = ffxMin(fBaseAccumulation, ffxLerp(fBaseAccumulation, 0.15f, ffxSaturate(ffxMax(0.0f, params.f4KVelocity / 0.5f))));
+    fBaseAccumulation = ffxMin(fBaseAccumulation, ffxLerp(fBaseAccumulation, 0.15f, ffxSaturate(ffxMax(0.0f, (params.f4KVelocity * VelocityFactor()) / 0.5f))));
 
     data.fHistoryWeight = fBaseAccumulation;
 }
diff --git a/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_callbacks_hlsl.h b/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_callbacks_hlsl.h
index f719674..e6f661c 100644
--- a/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_callbacks_hlsl.h
+++ b/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_callbacks_hlsl.h
@@ -796,7 +796,7 @@ FfxFloat32 Exposure()
     FfxFloat32 exposure = r_input_exposure[FfxUInt32x2(0, 0)].x;
 
 #if defined(__XBOX_SCARLETT)
-    if (exposure < 0.000030517578/** 2^15 */) {
+    if (exposure < 0.000030517578/** 2^-15 */) {
         exposure = 1.0f;
     }
 #else
diff --git a/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_common.h b/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_common.h
index 28993c6..87aa596 100644
--- a/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_common.h
+++ b/Shaders/shaders/fsr3upscaler/ffx_fsr3upscaler_common.h
@@ -123,7 +123,7 @@ struct AccumulationPassCommonParams
 
 FfxFloat32 Get4KVelocity(FfxFloat32x2 fMotionVector)
 {
-    return length(fMotionVector * FfxFloat32x2(3840.0f, 2160.0f)) * VelocityFactor();
+    return length(fMotionVector * FfxFloat32x2(3840.0f, 2160.0f));
 }
 
 struct RectificationBox