module Reactive.Banana.ALSA.Guitar where
import qualified Reactive.Banana.ALSA.Common as Common
import Sound.MIDI.Message.Channel.Voice (Pitch, toPitch, )
import Data.Maybe (mapMaybe, )
class Transpose pitch where
getPitch :: pitch -> Pitch
transpose :: Int -> pitch -> Maybe pitch
instance Transpose Pitch where
getPitch = id
transpose = Common.increasePitch
mapChordToString ::
(Transpose pitch, Ord pitch) =>
[Pitch] -> [pitch] -> [pitch]
mapChordToString strings chord =
mapMaybe (choosePitchForString chord) strings
choosePitchForString ::
(Transpose pitch, Ord pitch) =>
[pitch] -> Pitch -> Maybe pitch
choosePitchForString chord string =
let roundDown x d = x mod x d
minAbove x =
transpose
( roundDown (Common.subtractPitch string (getPitch x)) 12) x
in maximum (map minAbove chord)
stringPitches :: [Pitch]
stringPitches =
reverse $ map toPitch [40, 45, 50, 55, 59, 64]