//  Generated on <$_SCRIBE_DATE$>
//
//  Created by Sam Gateau on 7/5/16.
//  Copyright 2016 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

<@include ShadingModel.slh@>

<@func declareLightingDirectional(supportScattering)@>

void evalLightingDirectional(out vec3 diffuse, out vec3 specular, vec3 lightDir, vec3 lightIrradiance,
    SurfaceData surface,
    float metallic, vec3 fresnel, vec3 albedo, float shadow
<@if supportScattering@>
    , float scattering, vec4 midNormalCurvature, vec4 lowNormalCurvature
<@endif@>
    ) {

    // Attenuation
    vec3 lightEnergy = shadow * lightIrradiance;

    updateSurfaceDataWithLight(surface, -lightDir);

    evalFragShading(diffuse, specular, metallic, fresnel, surface, albedo
<@if supportScattering@>
    ,scattering, midNormalCurvature, lowNormalCurvature
<@endif@>
    );

    lightEnergy *= isDirectionalEnabled();
    diffuse *= lightEnergy * isDiffuseEnabled();
    specular *= lightEnergy * isSpecularEnabled();
}

<@endfunc@>