툰 셰이더 (셰이더 프로그래밍 입문)

난반사광을 단계적으로 감소시켜 표현한다.

Vertex Shader

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

struct VS_OUTPUT
{
   float4 mPosition : POSITION;
   float3 mDiffuse : TEXCOORD1;
};

float4x4 gWorldViewProjectionMatrix;
float4x4 gInvWorldMatrix;

float4 gWorldLightPosition;

VS_OUTPUT vs_main(VS_INPUT Input)
{
   VS_OUTPUT Output;
   
   Output.mPosition = mul(Input.mPosition, gWorldViewProjectionMatrix);
   
   float3 objectLightPosition = mul(gWorldLightPosition, gInvWorldMatrix);
   float3 lightDir = normalize(Input.mPosition.xyz - objectLightPosition);
   
   Output.mDiffuse = dot(-lightDir, normalize(Input.mNormal));
   
   return (Output);
}

Pixel Shader

float3 gSurfaceColor;

struct PS_INPUT
{
   float3 mDiffuse : TEXCOORD1;
};

float4 ps_main(PS_INPUT Input) : COLOR
{
   float3 diffuse = saturate(Input.mDiffuse);
   
   diffuse = ceil(diffuse * 5)/5.0f;
   
   return float4(gSurfaceColor * diffuse.xyz, 1);
}