/*

    Copyright (C) 2015 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Fragment shader that adjusts the luminance value based on the input sliders and renders the input texture.

 */

varying highp vec2 texCoordVarying;

precision mediump float;

uniform float lumaThreshold;

uniform float chromaThreshold;

uniform sampler2D SamplerY;

uniform sampler2D SamplerUV;

uniform mat3 colorConversionMatrix;

void main()

{

    mediump vec3 yuv;

    lowp vec3 rgb;

    // Subtract constants to map the video range start at 0

    yuv.x = (texture2D(SamplerY, texCoordVarying).r - (16.0/255.0))* lumaThreshold;

    yuv.yz = (texture2D(SamplerUV, texCoordVarying).rg - vec2(0.5, 0.5))* chromaThreshold;

    rgb = colorConversionMatrix * yuv;

    gl_FragColor = vec4(rgb,1);

}