//-----------------------------------------------------------------------------
// Lighting.fxh
//
// Microsoft XNA Community Game Platform
// Copyright (C) Microsoft Corporation. All rights reserved.
//-----------------------------------------------------------------------------
struct ColorPair
{
float3 Diffuse;
float3 Specular;
};
ColorPair ComputeLights(float3 eyeVector, float3 worldNormal, uniform int numLights)
{
float3x3 lightDirections = 0;
float3x3 lightDiffuse = 0;
float3x3 lightSpecular = 0;
float3x3 halfVectors = 0;
[unroll]
for (int i = 0; i < numLights; i++)
{
lightDirections[i] = float3x3(DirLight0Direction, DirLight1Direction, DirLight2Direction) [i];
lightDiffuse[i] = float3x3(DirLight0DiffuseColor, DirLight1DiffuseColor, DirLight2DiffuseColor) [i];
lightSpecular[i] = float3x3(DirLight0SpecularColor, DirLight1SpecularColor, DirLight2SpecularColor)[i];
halfVectors[i] = normalize(eyeVector - lightDirections[i]);
}
float3 dotL = mul(-lightDirections, worldNormal);
float3 dotH = mul(halfVectors, worldNormal);
float3 zeroL = step(0, dotL);
float3 diffuse = zeroL * dotL;
float3 specular = pow(max(dotH, 0) * zeroL, SpecularPower);
ColorPair result;
result.Diffuse = mul(diffuse, lightDiffuse) * DiffuseColor.rgb + EmissiveColor;
result.Specular = mul(specular, lightSpecular) * SpecularColor;
return result;
}
CommonVSOutput ComputeCommonVSOutputWithLighting(float4 position, float3 normal, uniform int numLights)
{
CommonVSOutput vout;
float4 pos_ws = mul(position, World);
float3 eyeVector = normalize(EyePosition - pos_ws.xyz);
float3 worldNormal = normalize(mul(normal, WorldInverseTranspose));
ColorPair lightResult = ComputeLights(eyeVector, worldNormal, numLights);
vout.Pos_ps = mul(position, WorldViewProj);
vout.Diffuse = float4(lightResult.Diffuse, DiffuseColor.a);
vout.Specular = lightResult.Specular;
vout.FogFactor = ComputeFogFactor(position);
return vout;
}
struct CommonVSOutputPixelLighting
{
float4 Pos_ps;
float3 Pos_ws;
float3 Normal_ws;
float FogFactor;
};
CommonVSOutputPixelLighting ComputeCommonVSOutputPixelLighting(float4 position, float3 normal)
{
CommonVSOutputPixelLighting vout;
vout.Pos_ps = mul(position, WorldViewProj);
vout.Pos_ws = mul(position, World).xyz;
vout.Normal_ws = normalize(mul(normal, WorldInverseTranspose));
vout.FogFactor = ComputeFogFactor(position);
return vout;
}
#define SetCommonVSOutputParamsPixelLighting \
vout.PositionPS = cout.Pos_ps; \
vout.PositionWS = float4(cout.Pos_ws, cout.FogFactor); \
vout.NormalWS = cout.Normal_ws;
