<@include gpu/Config.slh@>
<$VERSION_HEADER$>
//  Generated on <$_SCRIBE_DATE$>
//
//  Created by Sam Gateau on 5/16/17.
//  Copyright 2017 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 zone_draw.slh@>

<@include graphics/Light.slh@>

<@include LightingModel.slh@>
<$declareLightBuffer()$>

<@include LightDirectional.slh@>
<$declareLightingDirectional(_SCRIBE_NULL)$>

layout(location=0) in vec2 varTexCoord0;
layout(location=0) out vec4 _fragColor;

void main(void) {

    <$evalGlobeWidget()$>

    Light light = getKeyLight();
    vec3 lightDirection = normalize(getLightDirection(light));
    vec3 lightIrradiance = getLightIrradiance(light);
    vec3 color = vec3(0.0);
  
    const float INOUT_RATIO = 0.4;
    const float SUN_THRESHOLD = 0.99;

    vec3 outSpherePos = normalize(vec3(sphereUV, -sqrt(1.0 - sphereR2)));
    vec3 outNormal = vec3(getViewInverse() * vec4(outSpherePos, 0.0));

    float val = step(SUN_THRESHOLD, dot(-lightDirection, outNormal));

    color = lightIrradiance * vec3(val);

    if (sphereR2 < INOUT_RATIO * INOUT_RATIO * SCOPE_RADIUS2) {
        vec2 inSphereUV = sphereUV / INOUT_RATIO;
        vec3 inSpherePos = normalize(vec3(inSphereUV, sqrt(1.0 - dot(inSphereUV.xy, inSphereUV.xy))));
        vec3 inNormal = vec3(getViewInverse() * vec4(inSpherePos, 0.0));

        vec3 marbleColor = max(lightIrradiance * vec3(dot(-lightDirection, inNormal)), vec3(0.01));
        color += marbleColor;
    }

    color = color * 1.0 - base.w + base.xyz * base.w;
    const float INV_GAMMA_22 = 1.0 / 2.2;
    _fragColor = vec4(pow(color, vec3(INV_GAMMA_22)), 1.0);
}