48000.0 => float srate;

fun void setLP(BiQuad filter, float freq, float Q)
{
    (2.0 * pi * freq) / srate => float w0;
    math.sin(w0) / (2.0 * Q) => float alpha;
    math.cos(w0) => float cosw0;
    1.0 + alpha => float a0;
    ((1.0 - cosw0) / 2.0) / a0 => filter.b0;
    (1.0 - cosw0) / a0 => filter.b1;
    ((1.0 - cosw0) / 2.0) / a0 => filter.b2;
    (-2.0 * cosw0) / a0 => filter.a1;
    (1.0 - alpha) / a0 => filter.a2;
}

fun void setHP(BiQuad filter, float freq, float Q)
{
    (2.0 * pi * freq) / srate => float w0;
    math.sin(w0) / (2.0 * Q) => float alpha;
    math.cos(w0) => float cosw0;
    1.0 + alpha => float a0;
    ((1.0 + cosw0) / 2.0) / a0 => filter.b0;
    (-1.0 - cosw0) / a0 => filter.b1;
    ((1.0 + cosw0) / 2.0) / a0 => filter.b2;
    (-2.0 * cosw0) / a0 => filter.a1;
    (1.0 - alpha) / a0 => filter.a2;
}