Nazara: Point-Lighting fragment shader

vec3 lightDir = LightPosition - vWorldPos;

float att = max(LightAttenuation - LightInvRadius*length(lightDir), 0.0);
light += att * LightAmbient * (MaterialAmbient + SceneAmbient);

lightDir = normalize(lightDir);
float lambert = max(dot(normal, lightDir), 0.0);
light += att * lambert * LightDiffuse * MaterialDiffuse;

if (MaterialShininess > 0.0)
{
    vec3 reflection = reflect(-lightDir, normal);
    vec3 eyeVec = normalize(CameraPosition - vWorldPos);

    float specular = pow(max(dot(reflection, eyeVec), 0.0), MaterialShininess);

    light += att * specular * LightSpecular * MaterialSpecular;
}