RCMA/Unknown/Arpeggiated.hs

   1 {-# LANGUAGE Arrows #-}
   2
   3 module Arpeggiated where
   4
   5 import FRP.Yampa
   6
   7 import MIDI
   8 import Note
   9
  10 arpeggiated :: SF (ControllerValue, Event Note) (Event Note)
  11 arpeggiated = proc (c,n) -> do
  12   non     <- uncurry gate ^<< identity &&& arr (event False isOn) -< n
  13   non'    <- fmap majorThird ^<< delayEvent t                     -< non
  14   non''   <- fmap perfectFifth ^<< delayEvent t                   -< non'
  15   (nof',
  16    nof'') <- makeOff *** makeOff                                  -< (non',non'')
  17   -- It's assumed that the NoteOff event corresponding to n will be
  18   -- emitted.
  19   returnA -< mergeEvents [n, non, non', nof', non'', nof'']
  20     where onoffGap = 0.9*t
  21           t = 100000
  22           makeOff = delayEvent onoffGap <<^ fmap switchOnOff