Reactogon/Note.hs

   1 module Note where
   2
   3 import MIDI
   4
   5 isOn :: Note -> Bool
   6 isOn (NoteOn _ _) = True
   7 isOn _ = False
   8
   9 isOff :: Note -> Bool
  10 isOff = not . isOn
  11
  12 changePitch :: (Pitch -> Pitch) -> Note -> Note
  13 changePitch f (NoteOn  p v) = NoteOn  (f p) v
  14 changePitch f (NoteOff p v) = NoteOff (f p) v
  15
  16 changeVelocity :: (Velocity -> Velocity) -> Note -> Note
  17 changeVelocity f (NoteOn  p v) = NoteOn  p (f v)
  18 changeVelocity f (NoteOff p v) = NoteOff p (f v)
  19
  20 switchOnOff :: Note -> Note
  21 switchOnOff (NoteOn  p v) = NoteOff p v
  22 switchOnOff (NoteOff p v) = NoteOn  p v
  23
  24 perfectFifth :: Note -> Note
  25 perfectFifth = changePitch (toPitch . (+7) . fromPitch)
  26
  27 majorThird :: Note -> Note
  28 majorThird = changePitch (toPitch . (+4) . fromPitch)
  29
  30 minorThird :: Note -> Note
  31 minorThird = changePitch (toPitch . (+3) . fromPitch)