glsl test

const vec3 W = vec3(0.2125, 0.7154, 0.0721);
vec3 BrightnessContrastSaturation(vec3 color, float brt, float con, float sat)
{
    vec3 black = vec3(0., 0., 0.);
    vec3 middle = vec3(0.5, 0.5, 0.5);
    float luminance = dot(color, W);
    vec3 gray = vec3(luminance, luminance, luminance);

    vec3 brtColor = mix(black, color, brt);
    vec3 conColor = mix(middle, brtColor, con);
    vec3 satColor = mix(gray, conColor, sat);
    return satColor;
}
vec3 Exposure(vec3 color, float exposure) {
    return color * pow(2.0, exposure);
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    vec2 uv = fragCoord.xy / iResolution.xy;
    vec3 color = texture2D(iChannel0, uv).rgb;
    color = BrightnessContrastSaturation(color, 1.0, 1.0, 1.22);
    color = Exposure(color, 0.);
    fragColor = vec4(color, 1.);
}