bias & gain for VEX

bias_gain.vfl

float bias(float b; float x) {
    return pow(x, log(b)/log(0.5));
}

float gain(float g; float x) {
    if (x<0.5)
        return bias(1-g, 2*x)/2;
    else
        return 1-bias(1-g, 2-2*x)/2;        
}

// usage example
float x = v@P.x;
//v@P.y = bias(0.8, x);
//v@P.y = bias(0.2, x);
//v@P.y = gain(0.8, x);
v@P.y = gain(0.3 , x);