DirectionalLight

void RE_Direct_BlinnPhong( const in IncidentLight directLight, const in GeometricContext geometry, const in BlinnPhongMaterial material, inout ReflectedLight reflectedLight ) {
    float dotNL = saturate( dot( geometry.normal, directLight.direction ) );
    vec3 irradiance = dotNL * directLight.color;
    #ifndef PHYSICALLY_CORRECT_LIGHTS
        irradiance *= PI;
    #endif
    reflectedLight.directDiffuse += irradiance * BRDF_Diffuse_Lambert( material.diffuseColor );
    reflectedLight.directSpecular += irradiance * BRDF_Specular_BlinnPhong( directLight, geometry, material.specularColor, material.specularShininess ) * material.specularStrength;
}
void RE_IndirectDiffuse_BlinnPhong( const in vec3 irradiance, const in GeometricContext geometry, const in BlinnPhongMaterial material, inout ReflectedLight reflectedLight ) {
    reflectedLight.indirectDiffuse += irradiance * BRDF_Diffuse_Lambert( material.diffuseColor );
}