<@include gpu/Config.slh@>
<$VERSION_HEADER$>
//  Generated on <$_SCRIBE_DATE$>
//
//  simple_fade.frag
//  fragment shader
//
//  Created by Olivier Prat on 06/05/17.
//  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 DeferredBufferWrite.slh@>

<@include Fade.slh@>
<$declareFadeFragmentInstanced()$>

<@include render-utils/ShaderConstants.h@>

// the interpolated normal
layout(location=RENDER_UTILS_ATTR_NORMAL_WS) in vec3 _normalWS;
layout(location=RENDER_UTILS_ATTR_NORMAL_MS) in vec3 _normalMS;
layout(location=RENDER_UTILS_ATTR_COLOR) in vec4 _color;
layout(location=RENDER_UTILS_ATTR_TEXCOORD01) in vec4 _texCoord01;
#define _texCoord0 _texCoord01.xy
#define _texCoord1 _texCoord01.zw
layout(location=RENDER_UTILS_ATTR_POSITION_MS) in vec4 _positionMS;
layout(location=RENDER_UTILS_ATTR_POSITION_ES) in vec4 _positionES;
layout(location=RENDER_UTILS_ATTR_POSITION_WS) in vec4 _positionWS;

// For retro-compatibility
#define _normal      _normalWS
#define _modelNormal _normalMS
#define _position    _positionMS
#define _eyePosition _positionES

<@include procedural/ProceduralCommon.slh@>

#line 1001
//PROCEDURAL_BLOCK

#line 2030
void main(void) {
    vec3 fadeEmissive;
    FadeObjectParams fadeParams;

    <$fetchFadeObjectParamsInstanced(fadeParams)$>
    applyFade(fadeParams, _positionWS.xyz, fadeEmissive);

    vec3 normal = normalize(_normalWS.xyz); 
    vec3 diffuse = _color.rgb; 
    vec3 specular = DEFAULT_SPECULAR;
    float shininess = DEFAULT_SHININESS;
    float emissiveAmount = 0.0;

#ifdef PROCEDURAL

#ifdef PROCEDURAL_V1
    specular = getProceduralColor().rgb;
    // Procedural Shaders are expected to be Gamma corrected so let's bring back the RGB in linear space for the rest of the pipeline
    //specular = pow(specular, vec3(2.2));
    emissiveAmount = 1.0;
#else 
    emissiveAmount = getProceduralColors(diffuse, specular, shininess);
#endif

#endif

    const float ALPHA_THRESHOLD = 0.999;
    if (_color.a < ALPHA_THRESHOLD) {
        if (emissiveAmount > 0.0) {
            packDeferredFragmentTranslucent(
                normal,
                _color.a,
                specular+fadeEmissive,
                DEFAULT_ROUGHNESS);
        } else {
            packDeferredFragmentTranslucent(
                normal,
                _color.a,
                diffuse+fadeEmissive,
                DEFAULT_ROUGHNESS);
        }
    } else {
        if (emissiveAmount > 0.0) {
            packDeferredFragmentLightmap(
                normal,
                1.0,
                diffuse+fadeEmissive,
                max(0.0, 1.0 - shininess / 128.0),
                DEFAULT_METALLIC,
                specular);
        } else {
            packDeferredFragment(
                normal,
                1.0,
                diffuse,
                max(0.0, 1.0 - shininess / 128.0),
                length(specular),
                DEFAULT_EMISSIVE+fadeEmissive,
                DEFAULT_OCCLUSION,
                DEFAULT_SCATTERING);
        }
    }
}