Reactogon/Global/Clock.hs

   1 module Reactogon.Global.Clock where
   2
   3 import Reactogon.Auxiliary.Auxiliary
   4 import Reactogon.Semantics
   5 import FRP.Yampa
   6
   7 import Debug.Trace
   8
   9 tempo :: Tempo -> SF () Tempo
  10 tempo = constant
  11
  12 -- The initial value is arbitrary but never appears because the switch
  13 -- is immediate.
  14 metronome :: SF () Tempo -> SF () (Event Beat)
  15 metronome tempo = switch ((repeatedly (tempoToDTime 60) ())
  16                           &&&
  17                           (discard ^>> tempo >>> onChange')) (metronome' tempo)
  18   where metronome' :: SF () Tempo -> Tempo -> SF () (Event Beat)
  19         metronome' tempo t = (switch ((repeatedly (tempoToDTime t) ())
  20                                         &&&
  21                                        (discard ^>> tempo >>> onChange))
  22                              (metronome' tempo))
  23
  24 tempoToDTime :: Tempo -> DTime
  25 tempoToDTime = (60/) . fromIntegral