조명 구현

Vertex Shader
float4x4 gWorldMatrix;
float4x4 gViewMatrix;
float4x4 gProjectionMatrix;

float4 gWorldLightPosition;
float4 gWorldCameraPosition;

struct VS_INPUT
{
   float4 mPosition : POSITION;
   float3 mNormal : NORMAL;
};

struct VS_OUTPUT
{
   float4 mPosition : POSITION;
   float3 mDiffuse : TEXCOORD1;
   float3 mViewDir : TEXCOORD2;
   float3 mReflection : TEXCOORD3;
};

VS_OUTPUT vs_main(VS_INPUT Input)
{
   VS_OUTPUT Output;
   
   Output.mPosition = mul(Input.mPosition, gWorldMatrix);
   
   float3 lightDir = Output.mPosition.xyz - gWorldLightPosition.xyz;
   lightDir = normalize(lightDir);
   
   float3 viewDir = normalize(Output.mPosition.xyz - gWorldCameraPosition.xyz);
   Output.mViewDir = viewDir;
   
   Output.mPosition = mul(Output.mPosition, gViewMatrix);
   Output.mPosition = mul(Output.mPosition, gProjectionMatrix);
   
   float3 worldNormal = mul(Input.mNormal, (float3x3)gWorldMatrix);
   worldNormal = normalize(worldNormal);
   
   Output.mDiffuse = dot(-lightDir, worldNormal);
   Output.mReflection = reflect(lightDir, worldNormal);
   
   return Output;
}

Pixel Shader
struct PS_INPUT
{
   float3 mDiffuse : TEXCOORD1;
   float3 mViewDir : TEXCOORD2;
   float3 mReflection : TEXCOORD3;
};

float4 ps_main(PS_INPUT Input) : COLOR
{
   float3 diffuse = saturate(Input.mDiffuse);
   
   float3 reflection = normalize(Input.mReflection);
   float3 viewDir = normalize(Input.mViewDir);
   float3 specular = 0;
   
   if(diffuse.x > 0)
   {
     specular = saturate(dot(reflection, -viewDir));
     specular = pow(specular, 20.0f);
   }
   
   float3 ambient = float3(0.02f, 0.02f, 0.02f);
   
   return float4(ambient + diffuse + specular, 1);
};