<@include gpu/Config.slh@>
<$VERSION_HEADER$>
//  <$_SCRIBE_FILENAME$>
//  Generated on <$_SCRIBE_DATE$>
//
//  Created by Andrzej Kapolka on 9/15/14.
//  Copyright 2014 High Fidelity, Inc.
//  Copyright 2024 Overte e.V.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

<@include gpu/Color.slh@>
<@include DefaultMaterials.slh@>
<@include render-utils/ShaderConstants.h@>
<@include CullFace.slh@>

<@if HIFI_USE_FORWARD or HIFI_USE_TRANSLUCENT@>
    <@if not HIFI_USE_UNLIT@>
        <@include gpu/Transform.slh@>
        <$declareStandardCameraTransform()$>
    <@else@>
        <@include LightingModel.slh@>
    <@endif@>
<@endif@>

<@if HIFI_USE_FORWARD@>
    OUTPUT(0, vec4, _fragColor0);
<@else@>
    <@include DeferredBufferWrite.slh@>
<@endif@>

<@if not HIFI_USE_UNLIT@>
    <@include GlobalLight.slh@>
    <@include LightLocal.slh@>
    <$declareEvalGlobalLightingAlphaBlended()$>
<@endif@>

<@if HIFI_USE_FADE@>
    <@include Fade.slh@>
    <$declareFadeFragmentInstanced()$>
<@endif@>

<@if HIFI_USE_FORWARD or HIFI_USE_TRANSLUCENT@>
    <@if not HIFI_USE_UNLIT@>
        INPUT(RENDER_UTILS_ATTR_POSITION_ES, vec4, _positionES);
    <@endif@>

    // workaround for scribe only supporting (A or B) and not (A or B or C)
    <@if not HIFI_USE_FADE@>
        layout(location=RENDER_UTILS_ATTR_POSITION_WS) in vec4 _positionWS;
    <@endif@>
<@endif@>
<@if not HIFI_USE_FORWARD@>
    INPUT(RENDER_UTILS_ATTR_PREV_POSITION_CS, vec4, _prevPositionCS);
<@endif@>
<@if HIFI_USE_FADE@>
    INPUT(RENDER_UTILS_ATTR_POSITION_WS, vec4, _positionWS);
<@endif@>
INPUT(RENDER_UTILS_ATTR_NORMAL_WS, vec3, _normalWS);
INPUT(RENDER_UTILS_ATTR_COLOR, vec4, _color);
INPUT(RENDER_UTILS_ATTR_TEXCOORD01, vec4, _texCoord01);
#define _texCoord0 _texCoord01.xy
#define _texCoord1 _texCoord01.zw

TEXTURE(0, sampler2D, simpleTexture);

void main(void) {
    vec4 texel = texture(simpleTexture, _texCoord0);
    texel = mix(texel, color_sRGBAToLinear(texel), float(_color.a <= 0.0));
    texel.rgb *= _color.rgb;
    texel.a *= abs(_color.a);

<@if HIFI_USE_FADE@>
    vec3 fadeEmissive;
    FadeObjectParams fadeParams;
    <$fetchFadeObjectParamsInstanced(fadeParams)$>
    applyFade(fadeParams, _positionWS.xyz, fadeEmissive);
<@endif@>

<@if not HIFI_USE_UNLIT@>
    <@if HIFI_USE_TRANSLUCENT or HIFI_USE_FORWARD@>
        float metallic = DEFAULT_METALLIC;
        vec3 fresnel = getFresnelF0(metallic, texel.rgb);

        TransformCamera cam = getTransformCamera();

        vec3 fragNormalWS = evalFrontOrBackFaceNormal(normalize(_normalWS));
        vec3 fragPositionWS = _positionWS.xyz;
        vec3 fragToEyeWS = cam._viewInverse[3].xyz - fragPositionWS;
        vec3 fragToEyeDirWS = normalize(fragToEyeWS);
        SurfaceData surfaceWS = initSurfaceData(DEFAULT_ROUGHNESS, fragNormalWS, fragToEyeDirWS);

        vec4 localLighting = vec4(0.0);
        <$fetchClusterInfo(_positionWS)$>
        if (hasLocalLights(numLights, clusterPos, dims)) {
            localLighting = evalLocalLighting(cluster, numLights, fragPositionWS, surfaceWS,
                                              metallic, fresnel, texel.rgb, 0.0,
                                              vec4(0), vec4(0), texel.a);
        }

        vec4 color = vec4(evalGlobalLightingAlphaBlended(
            cam._viewInverse,
            1.0,
            DEFAULT_OCCLUSION,
            _positionES.xyz,
            fragNormalWS,
            texel.rgb,
            fresnel,
            metallic,
            DEFAULT_EMISSIVE
        <@if HIFI_USE_FADE@>
                + fadeEmissive
        <@endif@>
            ,
            surfaceWS, texel.a, localLighting.rgb),
            texel.a);

        <@if HIFI_USE_FORWARD@>
            _fragColor0 = color;
        <@else@>
            packDeferredFragmentTranslucentUnlit(color.a, color.rgb);
        <@endif@>
    <@else@>
        packDeferredFragment(
            _prevPositionCS,
            evalFrontOrBackFaceNormal(normalize(_normalWS)),
            1.0,
            texel.rgb,
            DEFAULT_ROUGHNESS,
            DEFAULT_METALLIC,
            DEFAULT_EMISSIVE
        <@if HIFI_USE_FADE@>
                + fadeEmissive
        <@endif@>
            ,
            DEFAULT_OCCLUSION,
            DEFAULT_SCATTERING);
    <@endif@>
<@else@>
    vec3 color = isUnlitEnabled() * (texel.rgb
        <@if HIFI_USE_FADE@>
                + fadeEmissive
        <@endif@>
        );
    <@if HIFI_USE_FORWARD@>
        _fragColor0 = vec4(color, texel.a);
    <@elif HIFI_USE_TRANSLUCENT@>
        packDeferredFragmentTranslucentUnlit(
            texel.a,
            color);
    <@else@>
        packDeferredFragmentUnlit(
            _prevPositionCS,
            evalFrontOrBackFaceNormal(normalize(_normalWS)),
            1.0,
            color);
    <@endif@>
<@endif@>
}