Merge pull request #346 from Unity-Technologies/Arrange-area-light-call

Arrange area light call

Assets/ScriptableRenderPipeline/HDRenderPipeline/Lighting/TilePass/TilePassLoop.hlsl

         {
             float3 localDiffuseLighting, localSpecularLighting;
 
-            EvaluateBSDF_Directional(context, V, posInput, prelightData,
-                                     _DirectionalLightDatas[i], bsdfData,
+            EvaluateBSDF_Directional(context, V, posInput, prelightData, _DirectionalLightDatas[i], bsdfData,
                                      localDiffuseLighting, localSpecularLighting);
 
             diffuseLighting += localDiffuseLighting;
         float3 localDiffuseLighting = float3(0.0, 0.0, 0.0);
         float3 localSpecularLighting = float3(0.0, 0.0, 0.0);
 
-        // !!!!!!!!!!!!!!
-        // COMPILER BEHAVIOR WARNING
+        // COMPILER BEHAVIOR WARNING!
+        // TODO: This is based on the current Lit.shader and can be different for any other way of implementing area lights, how to be generic and ensure performance ?
 
         i = 0;
         uint areaIndex = FetchIndex(areaLightStart, i);
-            EvaluateBSDF_Line(  context, V, posInput, prelightData, _LightDatas[areaIndex], bsdfData,
+            EvaluateBSDF_Area(  context, V, posInput, prelightData, _LightDatas[areaIndex], bsdfData, GPULIGHTTYPE_LINE,
                                 localDiffuseLighting, localSpecularLighting);
 
             diffuseLighting += localDiffuseLighting;
         while (i < areaLightCount) // Rectangle lights are the last area lights so no need to check type
         {
             areaIndex = FetchIndex(areaLightStart, i);
-            EvaluateBSDF_Area(  context, V, posInput, prelightData, _LightDatas[areaIndex], bsdfData,
+            EvaluateBSDF_Area(  context, V, posInput, prelightData, _LightDatas[areaIndex], bsdfData, GPULIGHTTYPE_RECTANGLE,
                                 localDiffuseLighting, localSpecularLighting);
 
             diffuseLighting += localDiffuseLighting;
 
     diffuseLighting += iblDiffuseLighting;
     specularLighting += iblSpecularLighting;
-#endif
-    // TODO: currently apply GI at the same time as reflection
-#ifdef PROCESS_ENV_LIGHT
-    // Add indirect diffuse + emissive (if any)
+    // Apply GI at the same time as reflection
+    // Add indirect diffuse + emissive (if any) - Ambient occlusion is multiply by emissive which is wrong but not a big deal
     diffuseLighting += bakeDiffuseLighting * context.ambientOcclusion;
 #endif
 
     {
         float3 localDiffuseLighting, localSpecularLighting;
 
-        EvaluateBSDF_Directional(context, V, posInput, prelightData,
-                                 _DirectionalLightDatas[i], bsdfData,
+        EvaluateBSDF_Directional(context, V, posInput, prelightData, _DirectionalLightDatas[i], bsdfData,
                                  localDiffuseLighting, localSpecularLighting);
 
         diffuseLighting += localDiffuseLighting;
     {
         float3 localDiffuseLighting, localSpecularLighting;
 
-        if (_LightDatas[i].lightType == GPULIGHTTYPE_LINE)
-        {
-            EvaluateBSDF_Line(  context, V, posInput, prelightData, _LightDatas[i], bsdfData,
-                                localDiffuseLighting, localSpecularLighting);
-        }
-        else
-        {
-            EvaluateBSDF_Area(  context, V, posInput, prelightData, _LightDatas[i], bsdfData,
-                                localDiffuseLighting, localSpecularLighting);
-        }
+        EvaluateBSDF_Area(  context, V, posInput, prelightData, _LightDatas[i], bsdfData, _LightDatas[i].lightType,
+                            localDiffuseLighting, localSpecularLighting);
 
         diffuseLighting += localDiffuseLighting;
         specularLighting += localSpecularLighting;
     specularLighting += iblSpecularLighting;
 
     // Add indirect diffuse + emissive (if any)
+    // Add indirect diffuse + emissive (if any) - Ambient occlusion is multiply by emissive which is wrong but not a big deal
     diffuseLighting += bakeDiffuseLighting * context.ambientOcclusion;
 
     ApplyDebug(context, posInput.positionWS, diffuseLighting, specularLighting);

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.hlsl

 
 // #define ELLIPSOIDAL_ATTENUATION
 
-void EvaluateBSDF_Area(LightLoopContext lightLoopContext,
-                       float3 V, PositionInputs posInput,
-                       PreLightData preLightData, LightData lightData, BSDFData bsdfData,
-                       out float3 diffuseLighting, out float3 specularLighting)
+void EvaluateBSDF_Rect( LightLoopContext lightLoopContext,
+                        float3 V, PositionInputs posInput,
+                        PreLightData preLightData, LightData lightData, BSDFData bsdfData,
+                        out float3 diffuseLighting, out float3 specularLighting)
 {
     float3 positionWS = posInput.positionWS;
 
         specularLighting = fresnelTerm * lightData.color * ltcValue;
     }
 #endif // LIT_DISPLAY_REFERENCE_AREA
+}
+
+void EvaluateBSDF_Area(LightLoopContext lightLoopContext,
+    float3 V, PositionInputs posInput,
+    PreLightData preLightData, LightData lightData, BSDFData bsdfData, int GPULightType,
+    out float3 diffuseLighting, out float3 specularLighting)
+{
+    if (GPULightType == GPULIGHTTYPE_LINE)
+    {
+        EvaluateBSDF_Line(lightLoopContext, V, posInput, preLightData, lightData, bsdfData, diffuseLighting, specularLighting);
+    }
+    else
+    {
+        EvaluateBSDF_Rect(lightLoopContext, V, posInput, preLightData, lightData, bsdfData, diffuseLighting, specularLighting);
+    }
 }
 
 //-----------------------------------------------------------------------------