From 78247b4c8a164fa776692acac8b12719b790f6cb Mon Sep 17 00:00:00 2001
From: "C. S." <76898260+Pentalimbed@users.noreply.github.com>
Date: Wed, 11 Dec 2024 19:44:48 +0000
Subject: [PATCH] feat: add saturation slider for ssgi il, remove backface mult
 (#845)

* feat: saturation slider for ssgi il

* chore: bump ssgi ver

* chore: more drastic IL bounce value
---
 .../Shaders/Features/ScreenSpaceGI.ini             |  2 +-
 .../Shaders/ScreenSpaceGI/common.hlsli             |  2 +-
 .../Shaders/ScreenSpaceGI/gi.cs.hlsl               |  4 ++--
 src/Features/ScreenSpaceGI.cpp                     | 14 ++++----------
 src/Features/ScreenSpaceGI.h                       |  6 +++---
 5 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/features/Screen Space GI/Shaders/Features/ScreenSpaceGI.ini b/features/Screen Space GI/Shaders/Features/ScreenSpaceGI.ini
index 67116d260..b889ce2cc 100644
--- a/features/Screen Space GI/Shaders/Features/ScreenSpaceGI.ini	
+++ b/features/Screen Space GI/Shaders/Features/ScreenSpaceGI.ini	
@@ -1,2 +1,2 @@
 [Info]
-Version = 3-0-0
\ No newline at end of file
+Version = 3-0-1
\ No newline at end of file
diff --git a/features/Screen Space GI/Shaders/ScreenSpaceGI/common.hlsli b/features/Screen Space GI/Shaders/ScreenSpaceGI/common.hlsli
index b9532f015..6d150a394 100644
--- a/features/Screen Space GI/Shaders/ScreenSpaceGI/common.hlsli	
+++ b/features/Screen Space GI/Shaders/ScreenSpaceGI/common.hlsli	
@@ -47,7 +47,7 @@ cbuffer SSGICB : register(b1)
 	float2 DepthFadeRange;
 	float DepthFadeScaleConst;
 
-	float BackfaceStrength;
+	float GISaturation;
 	float GIBounceFade;
 	float GIDistanceCompensation;
 	float GICompensationMaxDist;
diff --git a/features/Screen Space GI/Shaders/ScreenSpaceGI/gi.cs.hlsl b/features/Screen Space GI/Shaders/ScreenSpaceGI/gi.cs.hlsl
index d1c30ca4f..9cbb958c8 100644
--- a/features/Screen Space GI/Shaders/ScreenSpaceGI/gi.cs.hlsl	
+++ b/features/Screen Space GI/Shaders/ScreenSpaceGI/gi.cs.hlsl	
@@ -210,7 +210,7 @@ void CalculateGI(
 					if (dot(samplePos, normalSample) > 0)
 						normalSample = -normalSample;
 					float frontBackMult = -dot(normalSample, sampleHorizonVec);
-					frontBackMult = frontBackMult < 0 ? abs(frontBackMult) * BackfaceStrength : frontBackMult;  // backface
+					frontBackMult = frontBackMult < 0 ? 0.0 : frontBackMult;  // backface
 
 					if (frontBackMult > 0.f) {
 						float3 sampleHorizonVecWS = normalize(mul(FrameBuffer::CameraViewInverse[eyeIndex], half4(sampleHorizonVec, 0)).xyz);
@@ -246,7 +246,7 @@ void CalculateGI(
 	radianceY *= rcpNumSlices;
 	radianceY = lerp(radianceY, 0, depthFade);
 
-	radianceCoCg *= rcpNumSlices;
+	radianceCoCg *= rcpNumSlices * GISaturation;
 #endif
 
 	o_ao = visibility;
diff --git a/src/Features/ScreenSpaceGI.cpp b/src/Features/ScreenSpaceGI.cpp
index 8e881047f..b76845c7a 100644
--- a/src/Features/ScreenSpaceGI.cpp
+++ b/src/Features/ScreenSpaceGI.cpp
@@ -19,7 +19,7 @@ NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(
 	GIRadius,
 	Thickness,
 	DepthFadeRange,
-	BackfaceStrength,
+	GISaturation,
 	EnableGIBounce,
 	GIBounceFade,
 	GIDistanceCompensation,
@@ -194,6 +194,8 @@ void ScreenSpaceGI::DrawSettings()
 			ImGui::Separator();
 		}
 
+		Util::PercentageSlider("IL Saturation", &settings.GISaturation);
+
 		recompileFlag |= ImGui::Checkbox("Ambient Bounce", &settings.EnableGIBounce);
 		if (auto _tt = Util::HoverTooltipWrapper())
 			ImGui::Text(
@@ -208,14 +210,6 @@ void ScreenSpaceGI::DrawSettings()
 			if (auto _tt = Util::HoverTooltipWrapper())
 				ImGui::Text("How much of this frame's ambient+IL get carried to the next frame as source.");
 		}
-
-		if (showAdvanced) {
-			ImGui::Separator();
-
-			Util::PercentageSlider("Backface Lighting Mix", &settings.BackfaceStrength);
-			if (auto _tt = Util::HoverTooltipWrapper())
-				ImGui::Text("How bright at the back of objects is compared to the front. A small value to make up for foliage translucency.");
-		}
 	}
 
 	///////////////////////////////
@@ -574,7 +568,7 @@ void ScreenSpaceGI::UpdateSB()
 		data.DepthFadeRange = settings.DepthFadeRange;
 		data.DepthFadeScaleConst = 1 / (settings.DepthFadeRange.y - settings.DepthFadeRange.x);
 
-		data.BackfaceStrength = settings.BackfaceStrength;
+		data.GISaturation = settings.GISaturation;
 		data.GIBounceFade = settings.GIBounceFade;
 		data.GIDistanceCompensation = settings.GIDistanceCompensation;
 		data.GICompensationMaxDist = settings.AORadius;
diff --git a/src/Features/ScreenSpaceGI.h b/src/Features/ScreenSpaceGI.h
index c3886ca20..9a9514433 100644
--- a/src/Features/ScreenSpaceGI.h
+++ b/src/Features/ScreenSpaceGI.h
@@ -58,9 +58,9 @@ struct ScreenSpaceGI : Feature
 		float Thickness = 75.f;
 		float2 DepthFadeRange = { 4e4, 5e4 };
 		// gi
-		float BackfaceStrength = 0.f;
+		float GISaturation = .9f;
 		bool EnableGIBounce = true;
-		float GIBounceFade = .5f;
+		float GIBounceFade = .3f;
 		float GIDistanceCompensation = 0.f;
 		// mix
 		float AOPower = 2.f;
@@ -98,7 +98,7 @@ struct ScreenSpaceGI : Feature
 		float2 DepthFadeRange;
 		float DepthFadeScaleConst;
 
-		float BackfaceStrength;  //
+		float GISaturation;  //
 		float GIBounceFade;
 		float GIDistanceCompensation;
 		float GICompensationMaxDist;