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{-# OPTIONS_GHC -fno-warn-monomorphism-restriction #-}
import Control.Monad (unless, when)
import Foreign.C.String (withCString)
import Foreign.Ptr (nullPtr)
import qualified SDL
import qualified SDL.Raw.Mixer as Mix
import System.Environment (getArgs)
import System.Exit (exitFailure)
main :: IO ()
main = do
-- read arguments
fileName <- do
args <- getArgs
case args of
(arg : _) -> return arg
_ -> do
putStrLn "Usage: cabal run sdl2-mixer-raw <sound filename>"
exitFailure
-- initialize libraries
SDL.initialize [SDL.InitAudio]
_ <- Mix.init Mix.INIT_MP3
let rate = 22050
format = Mix.AUDIO_S16SYS
channels = 2
bufsize = 256
-- open device
result <- Mix.openAudio rate format channels bufsize
assert $ result == 0
-- open file
sound <- withCString fileName $ \cstr -> Mix.loadWAV cstr
assert $ sound /= nullPtr
-- play file
channel <- Mix.playChannel (-1) sound 0
assert $ channel /= -1
-- wait until finished
whileTrueM $ (/= 0) <$> Mix.playing channel
-- free resources
Mix.freeChunk sound
-- close device
Mix.closeAudio
-- quit
Mix.quit
SDL.quit
assert :: Bool -> IO ()
assert = flip unless $ error "Assertion failed"
whileTrueM :: Monad m => m Bool -> m ()
whileTrueM cond = do
loop <- cond
when loop $ whileTrueM cond
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