> import Sound.OSC {- hsc3 -}
> import Sound.SC3 {- hsc3 -}
> import Sound.SC3.UGen.Bindings.DB.External {- hsc3 -}

function to allocate buffers (fft,delay,feedback)
non-local so that they can be set using b_set &etc.
(& because pv_BinDelay fails with localBuf)

> mk_buf sz = do
>   _ <- async (b_alloc 10 (sz * 2) 1)
>   _ <- async (b_alloc 11 sz 1)
>   async (b_alloc 12 sz 1)

allocate buffers (number of bins)

    withSC3 (mk_buf 128)

function to generate bindelay filter

> mk_del z =
>     let maxdel = 0.5
>         c1 = fft 10 z 0.25 0 1 0
>         c2 = pv_BinDelay c1 maxdel 11 12 0.25
>     in z + ifft c2 0 0

start filter

> gr_01 = mk_del (soundIn 0)

set delay times (unary)

    withSC3 (sendMessage (b_fill 11 [(0,128,0.25)]))

set feedback gain

    withSC3 (sendMessage (b_fill 12 [(0,128,0.75)]))

function to generate sin table of n places in range (l,r)

> gen_sin l r n ph =
>     let f x = range l r (sin ((x / n) * 2 * pi + ph))
>     in map f [0..n]

set delay times (sin)

    withSC3 (sendMessage (b_setn1 11 0 (gen_sin 0 0.35 128 0)))

set feedback gain (sin)

    withSC3 (sendMessage (b_setn1 12 0 (gen_sin 0.75 0.95 128 pi)))

modulate delay times (lfo)

> gr_02 =
>     let o = range 0.15 0.35 (blip KR (1/23) 3)
>     in recordBuf KR 11 0 1 0 1 Loop 1 DoNothing o

modulate feedback gains (lfo)

> gr_03 =
>     let o = range 0.75 0.95 (blip KR (1/25) 5)
>     in recordBuf KR 12 0 1 0 1 Loop 1 DoNothing o

{-

pv_BinDelay - localBuf fails...

let sz = 128
    gen_sin l r n ph = -- function to generate sin table of n places in range (l,r)
      let f x = range l r (sin ((x / n) * 2 * pi + ph))
      in map f [0 .. n - 1]
    b1 = asLocalBuf 'α' (gen_sin 0 0.35 sz 0) -- delay times
    b2 = asLocalBuf 'β' (gen_sin 0.75 0.95 sz pi) -- feedback gain
    z = soundIn 0
    maxdel = 0.5
    c1 = fft (localBuf 'γ' 1 (sz * 2)) z 0.25 0 1 0
    c2 = X.pv_BinDelay c1 maxdel b1 b2 0.25
in z + ifft c2 0 0

-}