Keyword reduction: Assume ScreenSpace Shadows when Cascades enabled

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightPipeline.cs

             "_MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE",
             "_MAIN_LIGHT_DIRECTIONAL_SHADOW_SOFT",
             "_MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SOFT",
-            "_MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN",
-            "_MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN",
-            "_MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN_SOFT",
-            "_MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN_SOFT",
 
             "_MAIN_LIGHT_SPOT_SHADOW",
             "_MAIN_LIGHT_SPOT_SHADOW_SOFT"
                     m_MainLightKeywordString.Append("_DIRECTIONAL_SHADOW");
                     if (m_Asset.CascadeCount > 1)
                         m_MainLightKeywordString.Append("_CASCADE");
-
-                    if(m_RequireScreenSpaceShadows)
-                        m_MainLightKeywordString.Append("_SCREEN");
                 }
                 else
                 {

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/LightweightPassLit.hlsl

     half fogFactor = ComputeFogFactor(o.clipPos.z);
     o.fogFactorAndVertexLight = half4(fogFactor, vertexLight);
 
-//TODO: Macro?
-    #if    defined(_SHADOWS_SCREEN)
+    #if defined(_SHADOWS_CASCADE) //Assume screen space shadows when cascades enabled
-    #elif !defined(_SHADOWS_CASCADE)
+    #else
     o.shadowCoord = ComputeShadowCoord(o.posWS.xyz);
     #endif
 #endif

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/Shadows.hlsl

     #define _SHADOWS_PERSPECTIVE
 #endif
 
-#if defined(_MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN) || defined(_MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN_SOFT) || defined(_MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN) || defined(_MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN_SOFT)
-    #define _SHADOWS_SCREEN
-#endif
-
 TEXTURE2D(_ScreenSpaceShadowMap);
 SAMPLER(sampler_ScreenSpaceShadowMap);
 
         attenuation4.w = SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, shadowCoord.xyz + _ShadowOffset3.xyz);
         attenuation = dot(attenuation4, 0.25);
     #else
-        #ifdef _SHADOWS_SCREEN
+        #ifdef _SHADOWS_CASCADE //Assume screen space shadows when cascades enabled
             real fetchesWeights[16];
             real2 fetchesUV[16];
             SampleShadow_ComputeSamples_Tent_7x7(_ShadowmapSize, shadowCoord.xy, fetchesWeights, fetchesUV);
     return 1.0;
 #endif
 
-#ifdef _SHADOWS_SCREEN
+#ifdef _SHADOWS_CASCADE //Assume screen space shadows when cascades are enabled
-    #ifdef _SHADOWS_CASCADE
-        shadowCoord = ComputeShadowCoord(positionWS);
-    #endif
-        return SampleShadowmap(shadowCoord);
+    return SampleShadowmap(shadowCoord);
 #endif
 }
 

ScriptableRenderPipeline/LightweightPipeline/LWRP/Shaders/LightweightScreenSpaceShadows.shader

             // Lightweight shader library declares defines based on these keywords to avoid having to check them in the shaders
             // Core.hlsl defines _MAIN_LIGHT_DIRECTIONAL and _MAIN_LIGHT_SPOT (point lights can't be main light)
             // Shadow.hlsl defines _SHADOWS_ENABLED, _SHADOWS_SOFT, _SHADOWS_CASCADE, _SHADOWS_PERSPECTIVE
-            #pragma multi_compile _ _MAIN_LIGHT_DIRECTIONAL_SHADOW _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN _MAIN_LIGHT_DIRECTIONAL_SHADOW_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN_SOFT _MAIN_LIGHT_SPOT_SHADOW _MAIN_LIGHT_SPOT_SHADOW_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN _MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN_SOFT
+            #pragma multi_compile _ _MAIN_LIGHT_DIRECTIONAL_SHADOW _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE _MAIN_LIGHT_DIRECTIONAL_SHADOW_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SOFT _MAIN_LIGHT_SPOT_SHADOW _MAIN_LIGHT_SPOT_SHADOW_SOFT
             
             #pragma vertex   Vertex
             #pragma fragment Fragment

ScriptableRenderPipeline/LightweightPipeline/LWRP/Shaders/LightweightStandard.shader

             // Lightweight shader library declares defines based on these keywords to avoid having to check them in the shaders
             // Core.hlsl defines _MAIN_LIGHT_DIRECTIONAL and _MAIN_LIGHT_SPOT (point lights can't be main light)
             // Shadow.hlsl defines _SHADOWS_ENABLED, _SHADOWS_SOFT, _SHADOWS_CASCADE, _SHADOWS_PERSPECTIVE
-            #pragma multi_compile _ _MAIN_LIGHT_DIRECTIONAL_SHADOW _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN _MAIN_LIGHT_DIRECTIONAL_SHADOW_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SCREEN_SOFT _MAIN_LIGHT_SPOT_SHADOW _MAIN_LIGHT_SPOT_SHADOW_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN _MAIN_LIGHT_DIRECTIONAL_SHADOW_SCREEN_SOFT
+            #pragma multi_compile _ _MAIN_LIGHT_DIRECTIONAL_SHADOW _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE _MAIN_LIGHT_DIRECTIONAL_SHADOW_SOFT _MAIN_LIGHT_DIRECTIONAL_SHADOW_CASCADE_SOFT _MAIN_LIGHT_SPOT_SHADOW _MAIN_LIGHT_SPOT_SHADOW_SOFT
             #pragma multi_compile _ _MAIN_LIGHT_COOKIE
             #pragma multi_compile _ _ADDITIONAL_LIGHTS
             #pragma multi_compile _ _VERTEX_LIGHTS