Multiple Point Lights

enginecustom/light.vs

@@ -3,6 +3,12 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 
+/////////////
+// DEFINES //
+/////////////
+#define NUM_LIGHTS 4
+
+
 /////////////
 // GLOBALS //
 /////////////
@@ -13,6 +19,11 @@ cbuffer MatrixBuffer
 	matrix projectionMatrix;
 };
 
+cbuffer LightPositionBuffer
+{
+    float4 lightPosition[NUM_LIGHTS];
+};
+
 
 //////////////
 // TYPEDEFS //
@@ -29,7 +40,8 @@ struct PixelInputType
     float4 position : SV_POSITION;
     float2 tex : TEXCOORD0;
 	float3 normal : NORMAL;
-};
+	float3 lightPos[NUM_LIGHTS] : TEXCOORD1;
+ };
 
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -38,7 +50,9 @@ struct PixelInputType
 PixelInputType LightVertexShader(VertexInputType input)
 {
     PixelInputType output;
-    
+    float4 worldPosition;
+	int i;
+
 
 	// Change the position vector to be 4 units for proper matrix calculations.
     input.position.w = 1.0f;
@@ -57,5 +71,17 @@ PixelInputType LightVertexShader(VertexInputType input)
     // Normalize the normal vector.
     output.normal = normalize(output.normal);
 
+	// Calculate the position of the vertex in the world.
+    worldPosition = mul(input.position, worldMatrix);
+
+	for(i=0; i<NUM_LIGHTS; i++)
+	{
+		// Determine the light positions based on the position of the lights and the position of the vertex in the world.
+		output.lightPos[i] = lightPosition[i].xyz - worldPosition.xyz;
+
+		// Normalize the light position vectors.
+		output.lightPos[i] = normalize(output.lightPos[i]);
+	}
+
     return output;
 }