lambdasound-1.0.0: src/LambdaSound/Samples.hs

-- | This module contains some basic samples which can be combined to
-- generate interesting sounds 
module LambdaSound.Samples where

import Data.Coerce
import Data.Fixed (mod')
import Data.Massiv.Array qualified as M
import Data.Massiv.Array.Unsafe qualified as MU
import LambdaSound.Sound
import System.Random as R
import LambdaSound.Create

-- | Pure sinus sound
--
-- Warm and round
sineWave :: Hz -> Sound I Pulse
sineWave hz = (\t -> sin (coerce hz * coerce t * 2 * pi)) <$> time

-- | Triangle wave
--
-- Similar to sine but colder
triangleWave :: Hz -> Sound I Pulse
triangleWave hz =
  fmap
    ( \t ->
        let x = (coerce hz * coerce t) `mod'` 1
         in if x < 0.5
              then x * 4 - 1
              else 3 - x * 4
    )
    time

-- | Sawtooth wave
--
-- Warm and sharp
sawWave :: Hz -> Sound I Pulse
sawWave hz = (\t -> (coerce hz * coerce t * 2) `mod'` 2 - 1) <$> time

-- | Produces a square wave
--
-- Cold
squareWave :: Hz -> Sound I Pulse
squareWave hz = (\t -> fromIntegral @Int $ round ((coerce hz * t) `mod'` 1) * 2 - 1) <$> time

-- | Random noise between (-1,1). The given value is used as the seed value,
-- so the same seed will result in the same noise
noise :: Int -> Sound I Pulse
noise initial =
  computeOnce
    ( \sr ->
        M.compute @M.S $
          M.unfoldrS_
            (M.Sz1 sr.samples)
            (R.uniformR (-1, 1))
            (mkStdGen initial)
    )
    (fmap Pulse . flip MU.unsafeIndex <$> sampleIndex)