gistfile1.txt

inline svf~ (srate)
    let srate = (srate as f32)
    let invsrate = (/ (2.0 * srate))
    stateful-map
        inline "svf~" (src state...)
            # signal 523.0 0.0 0.0
            let in cutoff res drive = (src)
            drive := (drive * 0.1)
            freq := 2.0 * (sin (pi * (min 0.25 (cutoff * invsrate))))
            damp := (min 2.0
                (2.0 * (1.0 - (pow res 0.25))) (2.0 / freq - freq * 0.5))
            inline step (notch low high band)
                notch := (in - damp * band)
                low := (low + freq * band)
                high := (notch - low)
                band := (freq * high + band - drive * band * band * band)
                _ notch low high band
            let notch1 low1 high1 band1 = (step state...)
            let notch2 low2 high2 band2 = (step notch1 low1 high1 band1)
            _
                inline ()
                    let a = (vec4 notch1 low1 high1 band1)
                    let b = (vec4 notch2 low2 high2 band2)
                    a * 0.5 + b * 0.5
                \ notch2 low2 high2 band2
        # notch low high band
        \ 0.0 0.0 0.0 0.0