Nazara: Directionnal-Lighting fragment shader

vec3 lightDir = normalize(-LightDirection);

light += LightAmbient * (MaterialAmbient + SceneAmbient);

float lambert = max(dot(normal, lightDir), 0.0);
light += 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 += specular * LightSpecular * MaterialSpecular;
}