From 8885412350dac42fb0152afa65296c7e3b1ddd42 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Wed, 31 Aug 2022 23:16:29 +0200
Subject: [PATCH] Fix SSR shader on D3D10

---
 Content/Shaders/SSR.flax                  |  4 ++--
 Source/Shaders/GI/GlobalSurfaceAtlas.hlsl |  4 ++++
 Source/Shaders/Gather.hlsl                | 26 +++++++++++++++++++++++
 Source/Shaders/SSR.shader                 |  2 +-
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/Content/Shaders/SSR.flax b/Content/Shaders/SSR.flax
index 36d193f28..09d4db9d7 100644
--- a/Content/Shaders/SSR.flax
+++ b/Content/Shaders/SSR.flax
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:9403835414767ee73082d543b0e0f0827e2dfaf7e108ccb06145acb5f8576c03
-size 11173
+oid sha256:51826aca596ee714a557d74adcee138e674d30197cffebe454e20474713f3b37
+size 10916
diff --git a/Source/Shaders/GI/GlobalSurfaceAtlas.hlsl b/Source/Shaders/GI/GlobalSurfaceAtlas.hlsl
index 30bab5742..93633dbec 100644
--- a/Source/Shaders/GI/GlobalSurfaceAtlas.hlsl
+++ b/Source/Shaders/GI/GlobalSurfaceAtlas.hlsl
@@ -3,6 +3,10 @@
 #include "./Flax/Common.hlsl"
 #include "./Flax/Collisions.hlsl"
 
+#if CAN_USE_GATHER
+#define CAN_USE_GLOBAL_SURFACE_ATLAS 1
+#endif
+
 // This must match C++
 #define GLOBAL_SURFACE_ATLAS_CHUNKS_RESOLUTION 40 // Amount of chunks (in each direction) to split atlas draw distance for objects culling
 #define GLOBAL_SURFACE_ATLAS_CHUNKS_GROUP_SIZE 4
diff --git a/Source/Shaders/Gather.hlsl b/Source/Shaders/Gather.hlsl
index f6540fe86..76950bd66 100644
--- a/Source/Shaders/Gather.hlsl
+++ b/Source/Shaders/Gather.hlsl
@@ -70,4 +70,30 @@ float4 TextureGatherRed(Texture2D<float> tex, SamplerState sam, float2 uv, int2
 #endif
 }
 
+float4 TextureGatherGreen(Texture2D tex, SamplerState sam, float2 uv)
+{
+#if CAN_USE_GATHER
+	return tex.GatherGreen(sam, uv);
+#else
+    float x = tex.Sample(sam, uv, int2(0, 1)).g;
+    float y = tex.Sample(sam, uv, int2(1, 1)).g;
+    float z = tex.Sample(sam, uv, int2(1, 0)).g;
+    float w = tex.Sample(sam, uv, int2(0, 0)).g;
+    return float4(x, y, z, w);
+#endif
+}
+
+float4 TextureGatherBlue(Texture2D tex, SamplerState sam, float2 uv)
+{
+#if CAN_USE_GATHER
+	return tex.GatherBlue(sam, uv);
+#else
+    float x = tex.Sample(sam, uv, int2(0, 1)).b;
+    float y = tex.Sample(sam, uv, int2(1, 1)).b;
+    float z = tex.Sample(sam, uv, int2(1, 0)).b;
+    float w = tex.Sample(sam, uv, int2(0, 0)).b;
+    return float4(x, y, z, w);
+#endif
+}
+
 #endif
diff --git a/Source/Shaders/SSR.shader b/Source/Shaders/SSR.shader
index e6c57e943..765952cfb 100644
--- a/Source/Shaders/SSR.shader
+++ b/Source/Shaders/SSR.shader
@@ -134,7 +134,7 @@ float4 PS_RayTracePass(Quad_VS2PS input) : SV_Target0
     float3 reflectWS = ScreenSpaceReflectionDirection(input.TexCoord, gBuffer, gBufferData.ViewPos, TemporalEffect, TemporalTime, BRDFBias);
 
     // Fallback to Global SDF and Global Surface Atlas tracing
-#if USE_GLOBAL_SURFACE_ATLAS
+#if USE_GLOBAL_SURFACE_ATLAS && CAN_USE_GLOBAL_SURFACE_ATLAS
     GlobalSDFTrace sdfTrace;
     float maxDistance = 100000;
     float selfOcclusionBias = GlobalSDF.CascadeVoxelSize[0];