{-# OPTIONS_GHC -funbox-strict-fields -ddump-simpl-stats -O2 #-}
{-  -dverbose-core2core -ddump-simpl-iterations -ddump-asm -}
module Main (main) where

import qualified Sound.Frame.Stereo as Stereo
import qualified Data.StorableVector as SV

import Data.Int (Int16)

import GHC.Float (float2Int, )


saw :: SV.Vector Int16
saw =
   fst $ SV.unfoldrN 10000000
      (\x -> let y = mod (succ x) 10000
             in  Just (x,y))
      (0::Int16)

fsaw :: SV.Vector Int16
fsaw =
   fst $ SV.unfoldrN 10000000
      (\x0 ->
          let frac x = x - fromIntegral (float2Int x)
              x1 = frac (x0+440/44100)
              y = 2*x0-1
          in  Just (fromIntegral $ float2Int (y*fromIntegral(maxBound::Int16)), x1))
      (0::Float)

fstereo :: SV.Vector (Stereo.T Int16)
fstereo =
   fst $ SV.unfoldrN 10000000
      (\x0 ->
          let frac x = x - fromIntegral (float2Int x)
              x1 = frac (x0+440/44100)
              y0 = 2*x0-1
              toInt16 y =
                 fromIntegral $
                 float2Int (y*fromIntegral(maxBound::Int16))
          in  Just (Stereo.cons (toInt16 y0) (toInt16 y0), x1))
      (0::Float)

fchorus :: SV.Vector (Stereo.T Int16)
fchorus =
   fst $ SV.unfoldrN 10000000
      (\(x00,x10,x20,x30) ->
          let frac x = x - fromIntegral (float2Int x)
              x01 = frac (x00+441.0/44100)
              x11 = frac (x10+440.5/44100)
              x21 = frac (x20+439.5/44100)
              x31 = frac (x30+439.0/44100)
              sawWave x = 2*x-1
              yl = 0.5 * (sawWave x01 + sawWave x21)
              yr = 0.5 * (sawWave x11 + sawWave x31)
              toInt16 y =
                 fromIntegral $
                 float2Int (y*fromIntegral(maxBound::Int16))
          in  Just (Stereo.cons (toInt16 yl) (toInt16 yr),
                    (x01,x11,x21,x31)))
      (0::Float,0.25::Float,0.5::Float,0.75::Float)


main :: IO ()
main =
   SV.writeFile "speed.sw" fchorus