Added pipeline capabilities. Stripping shader meta pass and variants based on selected capabilities.

ScriptableRenderPipeline/Core/CoreRP/Utilities/CoreUtils.cs

             };
             return mat;
         }
+        public static bool HasFlag<T>(T mask, T flag) where T : IConvertible
+        {
+            return (mask.ToUInt32(null) & flag.ToUInt32(null)) != 0;
+        }
 
         public static void SetKeyword(CommandBuffer cmd, string keyword, bool state)
         {

ScriptableRenderPipeline/LightweightPipeline/LWRP/Editor/ShaderPreprocessor.cs

 using UnityEditor.Build;
 using UnityEditor.Rendering;
 using UnityEngine;
+using UnityEngine.Experimental.Rendering;
-    class ShaderPreprocessor : IPreprocessShaders
+    public class ShaderPreprocessor : IPreprocessShaders
     {
         int totalVariantsInputCount = 0;
         int totalVariantsOutputCount = 0;
 
         private bool StripUnusedVariant(ShaderSnippetData snippetData, ShaderCompilerData compilerData)
         {
-            if (snippetData.passName == "Meta")
+            if (snippetData.passType == PassType.Meta)
+                return true;
+
+            PipelineCapabilities capabilities = UnityEngine.Experimental.Rendering.LightweightPipeline.LightweightPipeline.GetPipelineCapabilities();
+
+            if (compilerData.shaderKeywordSet.IsEnabled(LightweightKeywords.AdditionalLights) &&
+                !CoreUtils.HasFlag(capabilities, PipelineCapabilities.AdditionalLights))
+                return true;
+
+            if (compilerData.shaderKeywordSet.IsEnabled(LightweightKeywords.VertexLights) &&
+                !CoreUtils.HasFlag(capabilities, PipelineCapabilities.VertexLights))
+                return true;
+
+            if (compilerData.shaderKeywordSet.IsEnabled(LightweightKeywords.DirectionalShadows) &&
+                !CoreUtils.HasFlag(capabilities, PipelineCapabilities.DirectionalShadows))
+                return true;
+
+            if (compilerData.shaderKeywordSet.IsEnabled(LightweightKeywords.LocalShadows) &&
+                !CoreUtils.HasFlag(capabilities, PipelineCapabilities.LocalShadows))
                 return true;
 
             return false;
         {
-           int initDataCount = data.Count;
+            int initDataCount = data.Count;
 
             for (int i = 0; i < data.Count; ++i)
             {

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightPipeline.cs

         public static int opaque;
     }
 
-    public class LightweightPipeline : RenderPipeline
+    public partial class LightweightPipeline : RenderPipeline
     {
         private readonly LightweightPipelineAsset m_Asset;
 
             m_Asset = asset;
 
             SetRenderingFeatures();
+            SetPipelineCapabilities(asset);
 
             PerFrameBuffer._GlossyEnvironmentColor = Shader.PropertyToID("_GlossyEnvironmentColor");
             PerFrameBuffer._SubtractiveShadowColor = Shader.PropertyToID("_SubtractiveShadowColor");
         {
             List<VisibleLight> visibleLights = lightData.visibleLights;
             int mainLightIndex = lightData.mainLightIndex;
-
-            bool shadowsEnabled = m_ShadowPass.HasDirectionalShadowmap || m_ShadowPass.HasLocalLightsShadowmap;
-            CoreUtils.SetKeyword(cmd, "_SHADOWS_ENABLED", shadowsEnabled);
-            CoreUtils.SetKeyword(cmd, "_LOCAL_SHADOWS_ENABLED", m_ShadowPass.HasLocalLightsShadowmap);
-
+            CoreUtils.SetKeyword(cmd, LightweightKeywords.AdditionalLightsText, lightData.totalAdditionalLightsCount > 0);
+            CoreUtils.SetKeyword(cmd, LightweightKeywords.MixedLightingSubtractiveText, m_MixedLightingSetup == MixedLightingSetup.Subtractive);
+            CoreUtils.SetKeyword(cmd, LightweightKeywords.VertexLightsText, vertexLightsCount > 0);
-            CoreUtils.SetKeyword(cmd, "_MAIN_LIGHT_COOKIE", mainLightIndex != -1 && LightweightUtils.IsSupportedCookieType(visibleLights[mainLightIndex].lightType) && visibleLights[mainLightIndex].light.cookie != null);
+            CoreUtils.SetKeyword(cmd, LightweightKeywords.MainLightCookieText, mainLightIndex != -1 && LightweightUtils.IsSupportedCookieType(visibleLights[mainLightIndex].lightType) && visibleLights[mainLightIndex].light.cookie != null);
-            CoreUtils.SetKeyword(cmd, "_ADDITIONAL_LIGHTS", lightData.totalAdditionalLightsCount > 0);
-            CoreUtils.SetKeyword(cmd, "_MIXED_LIGHTING_SUBTRACTIVE", m_MixedLightingSetup == MixedLightingSetup.Subtractive);
-            CoreUtils.SetKeyword(cmd, "_VERTEX_LIGHTS", vertexLightsCount > 0);
+            CoreUtils.SetKeyword(cmd, LightweightKeywords.DirectionalShadowsText, m_ShadowPass.HasDirectionalShadowmap);
+            CoreUtils.SetKeyword(cmd, LightweightKeywords.LocalShadowsText, m_ShadowPass.HasLocalLightsShadowmap);
+            
+            // TODO: Remove this. legacy particles support will be removed from Unity in 2018.3. This should be a shader_feature instead with prop exposed in the Standard particles shader.
             CoreUtils.SetKeyword(cmd, "SOFTPARTICLES_ON", m_RequireDepthTexture && m_Asset.RequireSoftParticles);
         }
 

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightPipelineCore.cs

+using System;
+using UnityEngine.Rendering;
+
+namespace UnityEngine.Experimental.Rendering.LightweightPipeline
+{
+    [Flags]
+    public enum PipelineCapabilities
+    {
+        AdditionalLights = (1 << 0),
+        VertexLights = (1 << 1),
+        DirectionalShadows = (1 << 2),
+        LocalShadows = (1 << 3),
+    }
+
+    public class LightweightKeywords
+    {
+        public static readonly string AdditionalLightsText = "_ADDITIONAL_LIGHTS";
+        public static readonly string VertexLightsText = "_VERTEX_LIGHTS";
+        public static readonly string MixedLightingSubtractiveText = "_MIXED_LIGHTING_SUBTRACTIVE";
+        public static readonly string MainLightCookieText = "_MAIN_LIGHT_COOKIE";
+        public static readonly string DirectionalShadowsText = "_SHADOWS_ENABLED";
+        public static readonly string LocalShadowsText = "_LOCAL_SHADOWS_ENABLED";
+        
+        public static readonly ShaderKeyword AdditionalLights = new ShaderKeyword(AdditionalLightsText);
+        public static readonly ShaderKeyword VertexLights = new ShaderKeyword(VertexLightsText);
+        public static readonly ShaderKeyword MixedLightingSubtractive = new ShaderKeyword(MixedLightingSubtractiveText);
+        public static readonly ShaderKeyword MainLightCookie = new ShaderKeyword(MainLightCookieText);
+        public static readonly ShaderKeyword DirectionalShadows = new ShaderKeyword(DirectionalShadowsText);
+        public static readonly ShaderKeyword LocalShadows = new ShaderKeyword(LocalShadowsText);
+    }
+
+    public partial class LightweightPipeline
+    {
+        static PipelineCapabilities pipelineCapabilities;
+
+        public static PipelineCapabilities GetPipelineCapabilities()
+        {
+            return pipelineCapabilities;
+        }
+
+        static void SetPipelineCapabilities(LightweightPipelineAsset pipelineAsset)
+        {
+            pipelineCapabilities = 0U;
+
+            if (pipelineAsset.MaxPixelLights < 1 && !pipelineAsset.SupportsVertexLight)
+                pipelineCapabilities |= PipelineCapabilities.AdditionalLights;
+
+            if (pipelineAsset.SupportsVertexLight)
+                pipelineCapabilities |= PipelineCapabilities.VertexLights;
+
+            if (pipelineAsset.ShadowSetting != ShadowType.NO_SHADOW)
+                pipelineCapabilities |= PipelineCapabilities.DirectionalShadows;
+
+            pipelineCapabilities |= PipelineCapabilities.LocalShadows;
+        }
+    }
+}
+

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightKeywords.cs

-using UnityEngine.Rendering;
-
-namespace UnityEngine.Experimental.Rendering.LightweightPipeline
-{
-    public class LightweightKeywords : MonoBehaviour
-    {
-        // Pipeline specific keywords
-        public static readonly ShaderKeyword AdditionalLights = new ShaderKeyword("_ADDITIONAL_LIGHTS");
-        public static readonly ShaderKeyword VertexLights = new ShaderKeyword("_VERTEX_LIGHTS");
-        public static readonly ShaderKeyword SubtractiveLight = new ShaderKeyword("_MIXED_LIGHTING_SUBTRACTIVE");
-        public static readonly ShaderKeyword DirectionalShadows = new ShaderKeyword("_SHADOWS_ENABLED");
-        public static readonly ShaderKeyword LocalShadows = new ShaderKeyword("_LOCAL_SHADOWS_ENABLED");
-
-        public static readonly ShaderKeyword Lightmap = new ShaderKeyword("DIRLIGHTMAP_COMBINED");
-        public static readonly ShaderKeyword DirectionalLightmap = new ShaderKeyword("LIGHTMAP_ON");
-    }
-}
-