Basic Shaders

/* Basic vertex shader */
void LimitedVS(
    float4 position : POSITION,
    float3 normal   : NORMAL,
    // outputs
    out float4 oPosition : POSITION,
    out float3 oNormal   : TEXCOORD0,
    out float3 oLightVec : TEXCOORD1,
    out float3 oHalfVec  : TEXCOORD2,
    out float3 oViewVec  : TEXCOORD3,
    // parameters
    uniform float4 lightPosition,
    uniform float3 eyePosition,
    uniform float4x4 wvpMat)
{
    // calculate output position
    oPosition = mul(wvpMat, position);

    // pass the main uvs and normals straight through unchanged
    oNormal = mul((float3x3)wMat, normal);

    // get object space light direction
    float3 lightVec = normalize(lightPosition.xyz - (worldPosition.xyz * lightPosition.w));

    // calculate half-angle
    float3 eyeVec = normalize(eyePosition - worldPosition.xyz);

    // set output registers
    oHalfVec = eyeVec + lightVec;
    oLightVec = lightVec;
    oViewVec = eyeVec;
}

/* Basic fragment program */
float4 LimitedPS(
    float3 normal   : TEXCOORD0,
    float3 lightVec : TEXCOORD1,
    float3 halfVec  : TEXCOORD2,
    float3 viewVec  : TEXCOORD3,
    // parameters
    uniform float3 lightColour,
    uniform float3 surfaceColour,
    uniform float specularHardness,
    uniform float specularIntensity) : COLOR
{
    // retrieve vectors and normalize
    float3 N = normalize(normal);
    float3 L = normalize(lightVec);
    float3 H = normalize(halfVec);
    float3 V = normalize(viewVec);

    // compute the diffuse factor
    float3 diffuseFactor = surfaceColour * saturate(dot(N, L)) * lightColour;

    // compute the specular factor
    float3 specFactor = pow(saturate(dot(N, H)), specularHardness) * specularIntensity;

    // simple phong shading
    float3 final = diffuseFactor + float3(specularFactor);

    // calculate and return final colour with alpha
    return float4(final, 1);
}