TestFileLoader.hs

{-
   TestFileLoader.hs (adapted from test_fileloader.c in freealut)
   Copyright (c) Sven Panne 2005-2016
   This file is part of the ALUT package & distributed under a BSD-style license.
   See the file LICENSE.
-}

import Control.Monad ( when, unless )
import Data.List ( intersperse )
import Sound.ALUT
import System.Exit ( exitFailure )
import System.IO ( hPutStrLn, stderr )

-- This program loads and plays a variety of files, basically an automated
-- version of Basic/PlayFile.hs.

playFile :: FilePath -> IO ()
playFile fileName = do
   -- Create an AL buffer from the given sound file.
   buf <- createBuffer (File fileName)

   -- Generate a single source, attach the buffer to it and start playing.
   source <- genObjectName
   buffer source $= Just buf
   play [source]

   -- Normally nothing should go wrong above, but one never knows...
   errs <- get alErrors
   unless (null errs) $ do
      hPutStrLn stderr (concat (intersperse "," [ d | ALError _ d <- errs ]))
      exitFailure

   -- Check every 0.1 seconds if the sound is still playing.
   let waitWhilePlaying = do
          sleep 0.1
          state <- get (sourceState source)
          when (state == Playing) $
             waitWhilePlaying
   waitWhilePlaying

main :: IO ()
main =
   -- Initialise ALUT and eat any ALUT-specific commandline flags.
   withProgNameAndArgs runALUT $ \_progName _args -> do

     -- If everything is OK, play the sound files and exit when finished.
     mapM_ playFile [ "file1.wav", "file2.au", "file3.raw" ]