fixing light culling

res/shaders/lib/Common.slang

@@ -6,18 +6,30 @@ struct ViewParameter
 {
     float4x4 viewMatrix;
     float4x4 projectionMatrix;
+    float4x4 inverseProjection;
     float4 cameraPos_WS;
     float2 screenDimensions;
 }
 layout(set = 0)
 ParameterBlock<ViewParameter> pViewParams;
 
-float3 screenToClip(float3 screen)
+float4 clipToView(float4 clip)
+{
+    float4 view = mul(pViewParams.inverseProjection, clip);
+
+    view = view / view.w;
+
+    return view;
+}
+
+float4 screenToView(float4 screen)
 {
     float2 texCoord = screen.xy / pViewParams.screenDimensions;
  
     // Convert to clip space 
-    return float3( float2( texCoord.x, 1.0f-texCoord.y ) * 2.0f - 1.0f, screen.z);
+    float4 clip = float4( float2( texCoord.x, 1.0f-texCoord.y ) * 2.0f - 1.0f, screen.z, screen.w);
+
+    return clipToView(clip);
 }
 
 struct Plane

res/shaders/lib/LightEnv.slang

@@ -32,27 +32,27 @@ struct PointLight : ILightEnv
         float illuminance = max(1 - d / colorRange.w, 0);
         return illuminance * brdf.evaluate(params.tbn, params.viewDir_TS, -normalize(lightDir_TS), colorRange.xyz);
     }
-    float3 getClipPosition()
+    float3 getViewPosition()
     {
-        float4 position_CS = mul(pViewParams.projectionMatrix, mul(pViewParams.viewMatrix, position_WS));
-        return position_CS.xyz / position_CS.w;
+        float4 position_VS = mul(pViewParams.viewMatrix, position_WS);
+        return position_VS.xyz / position_VS.w;
     }
 
-    bool insidePlane(Plane plane, float3 position_CS)
+    bool insidePlane(Plane plane, float3 position_VS)
     {
-        return dot(plane.n, position_CS) - plane.d < -colorRange.w;
+        return dot(plane.n, position_VS) - plane.d < -colorRange.w;
     }
 
-    bool insideFrustum(Frustum frustum, float3 position_CS, float minDepth, float maxDepth)
+    bool insideFrustum(Frustum frustum, float3 position_VS, float minDepth, float maxDepth)
     {
         bool result = true;
-        if(position_CS.z - colorRange.w > minDepth || position_CS.z + colorRange.w < maxDepth)
+        if(position_VS.z - colorRange.w > minDepth || position_VS.z + colorRange.w < maxDepth)
         {
             result = false;
         }
         for(int i = 0; i < 4 && result; ++i)
         {
-            if(insidePlane(frustum.sides[i], position_CS))
+            if(insidePlane(frustum.sides[i], position_VS))
             {
                 result = false;
             }