<!
//  LightingModel.slh
//  fragment shader
//
//  Created by Sam Gateau on 1/25/14.
//  Copyright 2013 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
!>
<@if not LIGHTING_MODEL_SLH@>
<@def LIGHTING_MODEL_SLH@>

<@include render-utils/ShaderConstants.h@>
<@func declareLightingModel()@>

struct LightingModel {
    vec4 _UnlitEmissiveLightmapBackground;
    vec4 _ScatteringDiffuseSpecularAlbedo;
    vec4 _AmbientDirectionalPointSpot;
    vec4 _ShowContourObscuranceWireframe;
    vec4 _HazeBloomSkinningBlendshape;
};

// See DeferredShader_BufferSlot in DeferredLightingEffect.cpp
LAYOUT(binding=RENDER_UTILS_BUFFER_LIGHT_MODEL) uniform lightingModelBuffer{
    LightingModel lightingModel;
};

float isUnlitEnabled() {
    return lightingModel._UnlitEmissiveLightmapBackground.x;
}
float isEmissiveEnabled() {
    return lightingModel._UnlitEmissiveLightmapBackground.y;
}
float isLightmapEnabled() {
    return lightingModel._UnlitEmissiveLightmapBackground.z;
}
float isBackgroundEnabled() {
    return lightingModel._UnlitEmissiveLightmapBackground.w;
}
float isObscuranceEnabled() {
    return lightingModel._ShowContourObscuranceWireframe.y;
}

float isScatteringEnabled() {
    return lightingModel._ScatteringDiffuseSpecularAlbedo.x;
}
float isDiffuseEnabled() {
    return lightingModel._ScatteringDiffuseSpecularAlbedo.y;
}
float isSpecularEnabled() {
    return lightingModel._ScatteringDiffuseSpecularAlbedo.z;
}
float isAlbedoEnabled() {
    return lightingModel._ScatteringDiffuseSpecularAlbedo.w;
}

float isAmbientEnabled() {
    return lightingModel._AmbientDirectionalPointSpot.x;
}
float isDirectionalEnabled() {
    return lightingModel._AmbientDirectionalPointSpot.y;
}
float isPointEnabled() {
    return lightingModel._AmbientDirectionalPointSpot.z;
}
float isSpotEnabled() {
    return lightingModel._AmbientDirectionalPointSpot.w;
}

float isShowLightContour() {
    return lightingModel._ShowContourObscuranceWireframe.x;
}

float isWireframeEnabled() {
    return lightingModel._ShowContourObscuranceWireframe.z;
}

float isHazeEnabled() {
    return lightingModel._HazeBloomSkinningBlendshape.x;
}
float isBloomEnabled() {
    return lightingModel._HazeBloomSkinningBlendshape.y;
}
float isSkinningEnabled() {
    return lightingModel._HazeBloomSkinningBlendshape.z;
}
float isBlendshapeEnabled() {
    return lightingModel._HazeBloomSkinningBlendshape.w;
}

<@endfunc@>
<$declareLightingModel()$>

struct SurfaceData {
    vec3 normal;
    vec3 eyeDir;
    vec3 lightDir;
    vec3 halfDir;
    float roughness;
    float roughness2;
    float roughness4;
    float ndotv;
    float ndotl;
    float ndoth;
    float ldoth;
    float smithInvG1NdotV;
};

<@if not GETFRESNEL0@>
<@def GETFRESNEL0@>
vec3 getFresnelF0(float metallic, vec3 metalF0) {
    // Enable continuous metallness value by lerping between dielectric
    // and metal fresnel F0 value based on the "metallic" parameter
    return mix(vec3(0.03), metalF0, metallic);
}
<@endif@>

<@endif@>