Merge pull request #1553 from Unity-Technologies/metal-fixes

metal fixes

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

 
 ## [Unreleased]
 
+### Fixed
+- Fixed a shader preprocessor issue when compiling DebugViewMaterialGBuffer.shader against Metal target
+- Added a temporary workaround to Lit.hlsl to avoid broken lighting code with Metal/AMD
+
 ### Added
 - Add option supportDitheringCrossFade on HDRP Asset to allow to remove shader variant during player build if needed
 - Add contact shadows for punctual lights (in additional shadow settings), only one light is allowed to cast contact shadows at the same time and so at each frame a dominant light is choosed among all light with contact shadows enabled.

com.unity.render-pipelines.high-definition/HDRP/Material/Lit/Lit.hlsl

     float3 rayOriginWS              = float3(0, 0, 0);
     float3 rayDirWS                 = float3(0, 0, 0);
     float mipLevel                  = 0;
-#if DEBUG_DISPLAY
+#ifdef DEBUG_DISPLAY
     int debugMode                   = 0;
 #endif
     float invScreenWeightDistance   = 0;
         rayDirWS                = preLightData.transparentRefractV;
         mipLevel                = preLightData.transparentSSMipLevel;
         invScreenWeightDistance = _SSRefractionInvScreenWeightDistance;
-#if DEBUG_DISPLAY
+#ifdef DEBUG_DISPLAY
         debugMode               = DEBUGLIGHTINGMODE_SCREEN_SPACE_TRACING_REFRACTION;
 #endif
     }
         rayDirWS                = preLightData.iblR;
         mipLevel                = PositivePow(preLightData.iblPerceptualRoughness, 0.8) * uint(max(_ColorPyramidScale.z - 1, 0));
         invScreenWeightDistance = _SSReflectionInvScreenWeightDistance;
-#if DEBUG_DISPLAY
+#ifdef DEBUG_DISPLAY
-#if DEBUG_DISPLAY
+#ifdef DEBUG_DISPLAY
             bool debug              = _DebugLightingMode == debugMode
                 && !any(int2(_MouseClickPixelCoord.xy) - int2(posInput.positionSS));
 #endif
         // Jitter the ray origin to trade some noise instead of banding effect
         ssRayInput.rayOriginWS = rayOriginWS + rayDirWS * SampleBayer4(posInput.positionSS + uint2(_FrameCount, uint(_FrameCount) / 4u)) * 0.1;
         ssRayInput.rayDirWS = rayDirWS;
-#if DEBUG_DISPLAY
+#ifdef DEBUG_DISPLAY
         ssRayInput.debug = debug;
 #endif
 
     float iblMipLevel;
     // TODO: We need to match the PerceptualRoughnessToMipmapLevel formula for planar, so we don't do this test (which is specific to our current lightloop)
     // Specific case for Texture2Ds, their convolution is a gaussian one and not a GGX one - So we use another roughness mip mapping.
+#if !defined(SHADER_API_METAL)
     if (IsEnvIndexTexture2D(lightData.envIndex))
     {
         // Empirical remapping
+#endif
     {
         iblMipLevel = PerceptualRoughnessToMipmapLevel(preLightData.iblPerceptualRoughness);
     }