src/RMCA/Global/Clock.hs

   1 {-# LANGUAGE MultiParamTypeClasses #-}
   2
   3 module RMCA.Global.Clock ( AbsBeat
   4                          , maxAbsBeat
   5                          , metronome
   6                          ) where
   7
   8 import FRP.Yampa
   9 import RMCA.Auxiliary
  10 import RMCA.Semantics
  11
  12 -- The absolute beat is the beat number of the global clock, there are
  13 -- 16 starting from 1.
  14 type AbsBeat = BeatNo
  15
  16 maxAbsBeat :: AbsBeat
  17 maxAbsBeat = 16
  18
  19 -- The global system tempo beats every 16th note, each beat is tagged
  20 -- with a beat number modulo sixteen. Each layer is then beating at
  21 -- its own fraction, discarding the unecessary beats.
  22 metronome :: SF Tempo (Event AbsBeat)
  23 metronome = accumBy (\pb _ -> nextBeatNo maxAbsBeat pb) 0 <<<
  24             repeatedlyS' () <<^ (15*) <<^ (1/) <<^ fromIntegral