RCMA/Layer/Layer.hs

   1 {-# LANGUAGE Arrows #-}
   2
   3 module RCMA.Layer.Layer where
   4
   5 import FRP.Yampa
   6 import RCMA.Global.Clock
   7 import RCMA.Semantics
   8
   9 -- Data representing the state of a layer. It is updated continuously.
  10 data Layer = Layer { relTempo    :: Double
  11                    , relPitch    :: RelPitch
  12                    , strength    :: Strength
  13                    , beatsPerBar :: BeatsPerBar
  14                    , beatCounter :: BeatNo
  15                    }
  16
  17 layerTempo :: SF (Tempo, Layer) Tempo
  18 layerTempo = proc (t, Layer { relTempo = r }) -> do
  19   returnA -< floor $ r * fromIntegral t
  20
  21 -- The layer is modified after the beat as been
  22 layerMetronome :: SF (Tempo, Layer) (Event (BeatNo, Layer))
  23 layerMetronome = proc (t, l@Layer { beatCounter = b , beatsPerBar = bpb}) -> do
  24   eb <- metronome <<< layerTempo -< (t, l)
  25   returnA -< eb `tag` let nb = nextBeatNo b bpb in (nb, l { beatCounter = nb })
  26
  27 -- A layer is a producer of events triggered by the system beat clock.
  28 layer :: SF () (Event Beat) ->  SF Layer (Event Note)
  29 layer beatSource = undefined