Dxc compatibility (#14)

* Add initial changes for SRP compatibility with the DXC compiler

* Add missing explicit binding specifications for UAVs used from PS. Undo involved preprocessor macro fix.

*Add explicit binding specifiers for UAVs used from pixel shadersx. This is needed to avoid binding index inconsistencies between SM 5.0 (our FXC use) and SM 5.1. (we want DXC as it can target SM > 5.0 in the first place)
*Remove compex macro change to avoid potentially introducing new bugs as this is an issue with the new preprocessor and not DXC which can work around it with the -flegacy-macro-expansion flag.

* Fix more DXC specific issues visible in HDRP_Tests project.

* Disable wave intrinsic usage errors when compiling with DXC

* Updated CHANGELOG.md files

* Replace all uses of COLOR semantic with SV_Target in pixel shader outputs

* Add comments explaning why certain changes were performed

Co-authored-by: lukas.taparauskas <[email protected]>
Co-authored-by: sebastienlagarde <[email protected]>

Author: Dredhog

TestProjects/HDRP_Tests/Assets/GraphicTests/Scenes/2x_Lighting/2004_AnimatedCookie/AnimatedCookie_Shader.shader

@@ -22,7 +22,7 @@ Shader "HDRenderPipeline/GraphicTests/2004_AnimatedCookie_AnimMat"
             float4      _Color;
             sampler2D   _Tex;
 
-            float4 frag(v2f_customrendertexture IN) : COLOR
+            float4 frag(v2f_customrendertexture IN) : SV_Target
             {
                 float f = _Time.y % 3;
 

TestProjects/HDRP_Tests/Assets/GraphicTests/Scenes/2x_Lighting/2004_AnimatedCookie/AnimatedCookie_Shader2.shader

@@ -129,7 +129,7 @@ Shader "HDRenderPipeline/GraphicTests/2004_AnimatedCookie_AnimMat2"
                 if (_StarsAnim[frame*STAR_COL*STAR_ROW + uv.y*STAR_ROW +uv.x]) c = 1;
             }
 
-            float4 frag(v2f_customrendertexture IN) : COLOR
+            float4 frag(v2f_customrendertexture IN) : SV_Target
             {
                 float4 c = float4(12.0/255.0, 65.0/255.0, 121.0/255.0, 1); // background color
 

com.unity.render-pipelines.core/CHANGELOG.md

@@ -49,6 +49,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Replaced calls to deprecated PlayerSettings.virtualRealitySupported property.
 - Enable RWTexture2D, RWTexture2DArray, RWTexture3D in gles 3.1
 - Updated macros to be compatible with the new shader preprocessor.
+- Updated shaders to be compatible with Microsoft's DXC.
 
 ## [7.1.1] - 2019-09-05
 

com.unity.render-pipelines.core/Editor/LookDev/Compositor.shader

@@ -391,7 +391,7 @@ Shader "Hidden/LookDev/Compositor"
             #pragma target 3.0
 
             float4 frag(float2 texcoord : TEXCOORD0,
-            UNITY_VPOS_TYPE vpos : VPOS) : COLOR
+            UNITY_VPOS_TYPE vpos : VPOS) : SV_Target
             {
                 float4 color = float4(ComputeColor(_Tex0MainView, _Tex0Shadows, ShadowMultiplier0, _ShadowColor0, texcoord) * exp2(ExposureValue1), 1.0);
                 color.rgb = ApplyToneMap(color.rgb);
@@ -409,7 +409,7 @@ Shader "Hidden/LookDev/Compositor"
             #pragma target 3.0
 
             float4 frag(float2 texcoord : TEXCOORD0,
-                        UNITY_VPOS_TYPE vpos : VPOS) : COLOR
+                        UNITY_VPOS_TYPE vpos : VPOS) : SV_Target
             {
                 float4 color = float4(ComputeColor(_Tex1MainView, _Tex1Shadows, ShadowMultiplier1, _ShadowColor1, texcoord) * exp2(ExposureValue2), 1.0);
                 color.rgb = ApplyToneMap(color.rgb);
@@ -427,7 +427,7 @@ Shader "Hidden/LookDev/Compositor"
             #pragma target 3.0
 
             float4 frag(float2 texcoord : TEXCOORD0,
-            UNITY_VPOS_TYPE vpos : VPOS) : COLOR
+            UNITY_VPOS_TYPE vpos : VPOS) : SV_Target
             {
                 float3 color1 = ComputeColor(_Tex0MainView, _Tex0Shadows, ShadowMultiplier0, _ShadowColor0, texcoord) * exp2(ExposureValue1);
                 float3 color2 = ComputeColor(_Tex1MainView, _Tex1Shadows, ShadowMultiplier1, _ShadowColor1, texcoord) * exp2(ExposureValue2);

com.unity.render-pipelines.core/Editor/LookDev/CubeToLatlong.shader

@@ -45,7 +45,7 @@ Shader "Hidden/LookDev/CubeToLatlong"
 
     float4 frag(    float2 texcoord : TEXCOORD0,
                     UNITY_VPOS_TYPE vpos : VPOS
-                    ) : COLOR
+                    ) : SV_Target
     {
         float2 texCoord = texcoord.xy;
         float theta = texCoord.y * UNITY_PI;

com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl

@@ -199,8 +199,8 @@
 #define LODDitheringTransition ERROR_ON_UNSUPPORTED_FUNCTION(LODDitheringTransition)
 #endif
 
-// On everything but GCN consoles we error on cross-lane operations
-#ifndef PLATFORM_SUPPORTS_WAVE_INTRINSICS
+// On everything but GCN consoles or DXC compiled shaders we error on cross-lane operations
+#if !defined(PLATFORM_SUPPORTS_WAVE_INTRINSICS) && !defined(UNITY_COMPILER_DXC)
 #define WaveActiveAllTrue ERROR_ON_UNSUPPORTED_FUNCTION(WaveActiveAllTrue)
 #define WaveActiveAnyTrue ERROR_ON_UNSUPPORTED_FUNCTION(WaveActiveAnyTrue)
 #define WaveGetLaneIndex ERROR_ON_UNSUPPORTED_FUNCTION(WaveGetLaneIndex)
@@ -701,6 +701,48 @@ uint GetMipCount(Texture2D tex)
 // Texture format sampling
 // ----------------------------------------------------------------------------
 
+// DXC no longer supports DX9-style HLSL syntax for sampler2D, tex2D and the like.
+// These are emulated for backwards compatibilit using our own small structs and functions which manually combine samplers and textures.
+#if defined(UNITY_COMPILER_DXC) && !defined(DXC_SAMPLER_COMPATIBILITY)
+#define DXC_SAMPLER_COMPATIBILITY 1
+struct sampler1D            { Texture1D t; SamplerState s; };
+struct sampler2D            { Texture2D t; SamplerState s; };
+struct sampler3D            { Texture3D t; SamplerState s; };
+struct samplerCUBE          { TextureCube t; SamplerState s; };
+
+float4 tex1D(sampler1D x, float v)              { return x.t.Sample(x.s, v); }
+float4 tex2D(sampler2D x, float2 v)             { return x.t.Sample(x.s, v); }
+float4 tex3D(sampler3D x, float3 v)             { return x.t.Sample(x.s, v); }
+float4 texCUBE(samplerCUBE x, float3 v)         { return x.t.Sample(x.s, v); }
+
+float4 tex1Dbias(sampler1D x, in float4 t)              { return x.t.SampleBias(x.s, t.x, t.w); }
+float4 tex2Dbias(sampler2D x, in float4 t)              { return x.t.SampleBias(x.s, t.xy, t.w); }
+float4 tex3Dbias(sampler3D x, in float4 t)              { return x.t.SampleBias(x.s, t.xyz, t.w); }
+float4 texCUBEbias(samplerCUBE x, in float4 t)          { return x.t.SampleBias(x.s, t.xyz, t.w); }
+
+float4 tex1Dlod(sampler1D x, in float4 t)           { return x.t.SampleLevel(x.s, t.x, t.w); }
+float4 tex2Dlod(sampler2D x, in float4 t)           { return x.t.SampleLevel(x.s, t.xy, t.w); }
+float4 tex3Dlod(sampler3D x, in float4 t)           { return x.t.SampleLevel(x.s, t.xyz, t.w); }
+float4 texCUBElod(samplerCUBE x, in float4 t)       { return x.t.SampleLevel(x.s, t.xyz, t.w); }
+
+float4 tex1Dgrad(sampler1D x, float t, float dx, float dy)              { return x.t.SampleGrad(x.s, t, dx, dy); }
+float4 tex2Dgrad(sampler2D x, float2 t, float2 dx, float2 dy)           { return x.t.SampleGrad(x.s, t, dx, dy); }
+float4 tex3Dgrad(sampler3D x, float3 t, float3 dx, float3 dy)           { return x.t.SampleGrad(x.s, t, dx, dy); }
+float4 texCUBEgrad(samplerCUBE x, float3 t, float3 dx, float3 dy)       { return x.t.SampleGrad(x.s, t, dx, dy); }
+
+float4 tex1D(sampler1D x, float t, float dx, float dy)              { return x.t.SampleGrad(x.s, t, dx, dy); }
+float4 tex2D(sampler2D x, float2 t, float2 dx, float2 dy)           { return x.t.SampleGrad(x.s, t, dx, dy); }
+float4 tex3D(sampler3D x, float3 t, float3 dx, float3 dy)           { return x.t.SampleGrad(x.s, t, dx, dy); }
+float4 texCUBE(samplerCUBE x, float3 t, float3 dx, float3 dy)       { return x.t.SampleGrad(x.s, t, dx, dy); }
+
+float4 tex1Dproj(sampler1D s, in float2 t)              { return tex1D(s, t.x / t.y); }
+float4 tex1Dproj(sampler1D s, in float4 t)              { return tex1D(s, t.x / t.w); }
+float4 tex2Dproj(sampler2D s, in float3 t)              { return tex2D(s, t.xy / t.z); }
+float4 tex2Dproj(sampler2D s, in float4 t)              { return tex2D(s, t.xy / t.w); }
+float4 tex3Dproj(sampler3D s, in float4 t)              { return tex3D(s, t.xyz / t.w); }
+float4 texCUBEproj(samplerCUBE s, in float4 t)          { return texCUBE(s, t.xyz / t.w); }
+#endif
+
 float2 DirectionToLatLongCoordinate(float3 unDir)
 {
     float3 dir = normalize(unDir);

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -506,6 +506,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fix for issue that prevented scene from being completely saved when baked reflection probes are present and lighting is set to auto generate.
 - Fixed drag area width at left of Light's intensity field in Inspector.
 - Fixed light type resolution when performing a reset on HDAdditionalLightData (case 1220931)
+- Fixed reliance on atan2 undefined behavior in motion vector debug shader.
 
 ### Changed
 - Color buffer pyramid is not allocated anymore if neither refraction nor distortion are enabled
@@ -614,6 +615,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Temporal Anti aliasing improvements.
 - Optimized PrepareLightsForGPU (cost reduced by over 25%) and PrepareGPULightData (around twice as fast now).
 - Moved scene view camera settings for HDRP from the preferences window to the scene view camera settings window.
+- Updated shaders to be compatible with Microsoft's DXC.
 
 ## [7.1.1] - 2019-09-05
 

com.unity.render-pipelines.high-definition/Runtime/Debug/DebugFullScreen.shader

@@ -241,6 +241,11 @@ Shader "Hidden/HDRP/DebugFullScreen"
                         d = 1.0 - saturate(d);
                     }
 
+                    // Explicitly handling the case where mv == float2(0, 0) as atan2(mv.x, mv.y) above would be atan2(0,0) which
+                    // is undefined and in practice can be incosistent between compilers (e.g. NaN on FXC and ~pi/2 on DXC)
+                    if(!any(mv))
+                        color = float3(0, 0, 0);
+
                     return float4(color + d.xxx, 1.0);
                 }
                 if (_FullScreenDebugMode == FULLSCREENDEBUGMODE_COLOR_LOG)

com.unity.render-pipelines.high-definition/Runtime/Material/Decal/DecalUtilities.hlsl

@@ -204,7 +204,7 @@ DecalSurfaceData GetDecalSurfaceData(PositionInputs posInput, inout float alpha)
 {
     uint mask = 0;
     // the code in the macros, gets moved inside the conditionals by the compiler
-    FETCH_DBUFFER(DBuffer, _DBufferTexture, posInput.positionSS);
+    FETCH_DBUFFER(DBuffer, _DBufferTexture, int2(posInput.positionSS.xy));
 
 #if defined(_SURFACE_TYPE_TRANSPARENT) && defined(HAS_LIGHTLOOP)  // forward transparent using clustered decals
     uint decalCount, decalStart;
@@ -258,7 +258,7 @@ DecalSurfaceData GetDecalSurfaceData(PositionInputs posInput, inout float alpha)
 
         if (!fastPath)
         {
-            // If we are not in fast path, v_lightIdx is not scalar, so we need to query the Min value across the wave. 
+            // If we are not in fast path, v_lightIdx is not scalar, so we need to query the Min value across the wave.
             s_decalIdx = WaveActiveMin(v_decalIdx);
             // If WaveActiveMin returns 0xffffffff it means that all lanes are actually dead, so we can safely ignore the loop and move forward.
             // This could happen as an helper lane could reach this point, hence having a valid v_lightIdx, but their values will be ignored by the WaveActiveMin

com.unity.render-pipelines.high-definition/Runtime/Material/Decal/ShaderVariablesDecal.hlsl

@@ -10,7 +10,7 @@ TEXTURE2D(_DecalAtlas2D);
 SAMPLER(_trilinear_clamp_sampler_DecalAtlas2D);
 
 #ifdef PLATFORM_SUPPORTS_BUFFER_ATOMICS_IN_PIXEL_SHADER
-RWStructuredBuffer<uint> _DecalPropertyMaskBuffer;
+RWStructuredBuffer<uint> _DecalPropertyMaskBuffer : register(u4);
 StructuredBuffer<uint> _DecalPropertyMaskBufferSRV;
 #endif