point light sphere optimization

Effects/DeferredPBR_PointLightEffect.cs

@@ -18,6 +18,8 @@ namespace Kav
 
         EffectParameter farPlaneParam;
 
+        EffectParameter worldViewProjectionParam;
+
         public Texture2D GPosition { get; set; }
         public Texture2D GAlbedo { get; set; }
         public Texture2D GNormal { get; set; }
@@ -31,6 +33,42 @@ namespace Kav
 
         public float FarPlane { get; set; }
 
+        Matrix world = Matrix.Identity;
+        Matrix view = Matrix.Identity;
+        Matrix projection = Matrix.Identity;
+
+        EffectDirtyFlags dirtyFlags = EffectDirtyFlags.All;
+
+        public Matrix World
+        {
+            get { return world; }
+            set
+            {
+                world = value;
+                dirtyFlags |= EffectDirtyFlags.WorldViewProj;
+            }
+        }
+
+        public Matrix View
+        {
+            get { return view; }
+            set
+            {
+                view = value;
+                dirtyFlags |= EffectDirtyFlags.WorldViewProj;
+            }
+        }
+
+        public Matrix Projection
+        {
+            get { return projection; }
+            set
+            {
+                projection = value;
+                dirtyFlags |= EffectDirtyFlags.WorldViewProj;
+            }
+        }
+
         public DeferredPBR_PointLightEffect(GraphicsDevice graphicsDevice) : base(graphicsDevice, Resources.DeferredPBR_PointLightEffect)
         {
             CacheEffectParameters();
@@ -73,6 +111,13 @@ namespace Kav
             pointLightColorParam.SetValue(PointLightColor);
 
             farPlaneParam.SetValue(FarPlane);
+
+            if ((dirtyFlags & EffectDirtyFlags.WorldViewProj) != 0)
+            {
+                worldViewProjectionParam.SetValue(world * view * projection);
+
+                dirtyFlags &= ~EffectDirtyFlags.WorldViewProj;
+            }
         }
 
         void CacheEffectParameters()
@@ -89,6 +134,8 @@ namespace Kav
             pointLightColorParam           = Parameters["PointLightColor"];
 
             farPlaneParam                  = Parameters["FarPlane"];
+
+            worldViewProjectionParam       = Parameters["WorldViewProjection"];
         }
     }
 }

Effects/HLSL/DeferredPBR_PointLightEffect.fx

@@ -1,3 +1,5 @@
+// Assumes you are drawing a sphere!!
+
 #include "Macros.fxh" //from FNA
 #include "Lighting.fxh" 
 #include "Shadow.fxh"
@@ -19,26 +21,27 @@ BEGIN_CONSTANTS
 
 MATRIX_CONSTANTS
 
+    float4x4 WorldViewProjection _vs(c0)                _cb(c4);
+
 END_CONSTANTS
 
 struct VertexInput
 {
     float4 Position : POSITION;
-    float2 TexCoord : TEXCOORD;
 };
 
 struct PixelInput
 {
     float4 Position : SV_POSITION;
-    float2 TexCoord : TEXCOORD0;
+    float4 ScreenPosition : TEXCOORD0;
 };
 
 PixelInput main_vs(VertexInput input)
 {
     PixelInput output;
 
-    output.Position = input.Position;
-    output.TexCoord = input.TexCoord;
+    output.Position = mul(input.Position, WorldViewProjection);
+    output.ScreenPosition = output.Position;
     
     return output;
 }
@@ -73,10 +76,13 @@ float4 ComputeColor(
 
 float4 main_ps(PixelInput input) : SV_TARGET0
 {
-    float3 worldPosition = SAMPLE_TEXTURE(gPosition, input.TexCoord).rgb;
-    float3 normal = SAMPLE_TEXTURE(gNormal, input.TexCoord).xyz;
-    float3 albedo = SAMPLE_TEXTURE(gAlbedo, input.TexCoord).rgb;
-    float2 metallicRoughness = SAMPLE_TEXTURE(gMetallicRoughness, input.TexCoord).rg;
+    input.ScreenPosition.xy /= input.ScreenPosition.w;
+    float2 texCoord = 0.5f * float2(input.ScreenPosition.x,-input.ScreenPosition.y) + 0.5f;
+    
+    float3 worldPosition = SAMPLE_TEXTURE(gPosition, texCoord).rgb;
+    float3 normal = SAMPLE_TEXTURE(gNormal, texCoord).xyz;
+    float3 albedo = SAMPLE_TEXTURE(gAlbedo, texCoord).rgb;
+    float2 metallicRoughness = SAMPLE_TEXTURE(gMetallicRoughness, texCoord).rg;
 
     return ComputeColor(
         worldPosition,

Kav.Core.csproj

@@ -64,6 +64,9 @@
     <EmbeddedResource Include="Models\UnitCube.glb">
       <LogicalName>Kav.Resources.UnitCube.glb</LogicalName>
 		</EmbeddedResource>
+    <EmbeddedResource Include="Models\UnitSphere.glb">
+      <LogicalName>Kav.Resources.UnitSphere.glb</LogicalName>
+		</EmbeddedResource>
   </ItemGroup>
 
 </Project>

Kav.Framework.csproj

@@ -64,6 +64,9 @@
     <EmbeddedResource Include="Models\UnitCube.glb">
       <LogicalName>Kav.Resources.UnitCube.glb</LogicalName>
 		</EmbeddedResource>
+    <EmbeddedResource Include="Models\UnitSphere.glb">
+      <LogicalName>Kav.Resources.UnitSphere.glb</LogicalName>
+		</EmbeddedResource>
   </ItemGroup>
 
 </Project>

Lights/PointLight.cs

@@ -4,15 +4,23 @@ namespace Kav
 {
     public struct PointLight
     {
+        public static double ATTENUATION_EPSILON = 0.1;
+
         public Vector3 Position { get; }
         public Color Color { get; }
         public float Intensity { get; }
 
+        public float EffectiveRadius { get; }
+        public BoundingSphere BoundingSphere { get; }
+
         public PointLight(Vector3 position, Color color, float intensity = 1f)
         {
             Position = position;
             Color = color;
             Intensity = intensity;
+
+            EffectiveRadius = (float) System.Math.Sqrt(Intensity);
+            BoundingSphere = new BoundingSphere(position, EffectiveRadius);
         }
     }
 }

Renderer.cs

@@ -28,6 +28,7 @@ namespace Kav
         private DiffuseLitSpriteEffect DiffuseLitSpriteEffect { get; }
 
         private Kav.Model UnitCube { get; }
+        private Kav.Model UnitSphere { get; }
 
         public Renderer(
             GraphicsDevice graphicsDevice
@@ -61,6 +62,11 @@ namespace Kav
                 GraphicsDevice,
                 Smuggler.Importer.ImportGLB(GraphicsDevice, new MemoryStream(Resources.UnitCubeModel))
             );
+
+            UnitSphere = Kav.ModelLoader.Load(
+                graphicsDevice,
+                Smuggler.Importer.ImportGLB(graphicsDevice, new MemoryStream(Resources.UnitSphereModel))
+            );
         }
 
         public static (T[], DynamicVertexBuffer) CreateInstanceVertexBuffer<T>(
@@ -461,7 +467,16 @@ namespace Kav
             PointLight pointLight
         ) {
             GraphicsDevice.SetRenderTarget(renderTarget);
-            GraphicsDevice.DepthStencilState = DepthStencilState.DepthRead;
+            if (Vector3.Distance(camera.Position, pointLight.Position) < pointLight.EffectiveRadius)
+            {
+                GraphicsDevice.RasterizerState = RasterizerState.CullClockwise;
+            }
+            else
+            {
+                GraphicsDevice.RasterizerState = RasterizerState.CullCounterClockwise;
+            }
+
+            GraphicsDevice.DepthStencilState = DepthStencilState.None;
             GraphicsDevice.BlendState = BlendState.Additive;
 
             DeferredPointLightEffect.GPosition = gPosition;
@@ -478,7 +493,17 @@ namespace Kav
 
             DeferredPointLightEffect.FarPlane = 25f; // FIXME: magic value
 
-            RenderFullscreenEffect(DeferredPointLightEffect);
+            DeferredPointLightEffect.World =
+                Matrix.CreateScale(pointLight.EffectiveRadius) *
+                Matrix.CreateTranslation(pointLight.Position);
+            DeferredPointLightEffect.View = camera.View;
+            DeferredPointLightEffect.Projection = camera.Projection;
+
+            RenderIndexed(
+                GraphicsDevice, 
+                UnitSphere.Meshes[0].MeshParts[0],
+                DeferredPointLightEffect
+            );
         }
 
         public void RenderDirectionalLight(
@@ -492,6 +517,7 @@ namespace Kav
             DirectionalLight directionalLight
         ) {
             GraphicsDevice.SetRenderTarget(renderTarget);
+            GraphicsDevice.RasterizerState = RasterizerState.CullCounterClockwise;
             GraphicsDevice.DepthStencilState = DepthStencilState.DepthRead;
             GraphicsDevice.BlendState = BlendState.Additive;
 

Resources.cs

@@ -195,6 +195,18 @@ namespace Kav
             }
         }
 
+        public static byte[] UnitSphereModel
+        {
+            get
+            {
+                if (unitSphereModel == null)
+                {
+                    unitSphereModel = GetResource("UnitSphere.glb");
+                }
+                return unitSphereModel;
+            }
+        }
+
         private static byte[] ambientLightEffect;
         private static byte[] pointLightEffect;
         private static byte[] directionalLightEffect;
@@ -212,6 +224,7 @@ namespace Kav
         private static byte[] paletteCrushEffect;
 
         private static byte[] unitCubeModel;
+        private static byte[] unitSphereModel;
 
         private static byte[] GetResource(string name)
         {