<@include gpu/Config.slh@>
<$VERSION_HEADER$>
//  Generated on <$_SCRIBE_DATE$>
//
//  taa.frag
//  fragment shader
//
//  Created by Sam Gateau on 8/14/2017
//  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 taa.slh@>

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

void main() {
    vec2 fragUV = varTexCoord0;

    // Debug region before debug or fxaa region X
    float distToRegionFXAA = fragUV.x - taa_getRegionFXAA().x;  
    if (distToRegionFXAA > 0.0) {
        outFragColor = vec4(taa_evalFXAA(fragUV), 1.0);
        return;
    }

    vec2 fragVel = taa_fetchVelocityMapBest(fragUV).xy;

    vec3 sourceColor;
    vec3 historyColor;
    vec2 prevFragUV = taa_fetchSourceAndHistory(fragUV, fragVel, sourceColor, historyColor);

    vec3 nextColor = sourceColor;

    // clamp history to neighbourhood of current sample
    historyColor = mix(historyColor, taa_evalConstrainColor(sourceColor, fragUV, fragVel, historyColor), float(taa_constrainColor()));

    nextColor = mix(mix(historyColor, sourceColor, params.blend), taa_evalFeedbackColor(sourceColor, historyColor, params.blend), float(taa_feedbackColor()));

    outFragColor = vec4(taa_resolveColor(nextColor), 1.0);
}