FFI.hs

{-# OPTIONS -fffi #-}

{-
    JACK bindings for Haskell
    Copyright (C) 2007 Soenke Hahn

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-}

module Sound.JACK.FFI where

import Foreign.Ptr (Ptr, FunPtr)
import Foreign.C.String (CString)
import Foreign.C.Types (CUInt, CInt, CChar, CFloat, CULong)

import Data.Bits (setBit, bit)

import Data.Array(Ix)



foreign import ccall "static jack/jack.h jack_client_open"
  client_open :: CString -> CULong -> Ptr CULong -> CString -> IO (Ptr ())

foreign import ccall "static jack/jack.h jack_client_new"
  client_new :: CString -> IO (Ptr ())


data OpenOptions =
     NoStartServer
   | UseExactName
   | ServerName
     deriving (Enum, Eq, Ord, Show, Ix)

wordNullOption, wordNoStartServer, wordUseExactName, wordServerName :: CULong
wordNullOption    = 0
wordNoStartServer = flagToWord NoStartServer
wordUseExactName  = flagToWord UseExactName
wordServerName    = flagToWord ServerName



data Status =
     Failure
   | InvalidOption
   | NameNotUnique
   | ServerStarted
   | ServerFailed
   | ServerError
   | NoSuchClient
   | LoadFailure
   | InitFailure
   | ShmFailure
   | VersionError
     deriving (Enum, Eq, Ord, Show, Ix)

wordFailure, wordInvalidOption, wordNameNotUnique, wordServerStarted,
  wordServerFailed, wordServerError, wordNoSuchClient, wordLoadFailure,
  wordInitFailure, wordShmFailure, wordVersionError :: CULong
wordFailure       = flagToWord Failure
wordInvalidOption = flagToWord InvalidOption
wordNameNotUnique = flagToWord NameNotUnique
wordServerStarted = flagToWord ServerStarted
wordServerFailed  = flagToWord ServerFailed
wordServerError   = flagToWord ServerError
wordNoSuchClient  = flagToWord NoSuchClient
wordLoadFailure   = flagToWord LoadFailure
wordInitFailure   = flagToWord InitFailure
wordShmFailure    = flagToWord ShmFailure
wordVersionError  = flagToWord VersionError



foreign import ccall "static jack/jack.h jack_port_register"
  port_register :: Ptr () -> Ptr (CChar) -> Ptr (CChar) -> 
        CULong -> CULong -> IO (Ptr ())

foreign import ccall "static jack/jack.h jack_set_process_callback"
  set_process_callback :: 
        Ptr () -> FunPtr (CUInt -> Ptr (CChar) -> IO (CInt)) -> Ptr (CChar) -> IO (CInt)

foreign import ccall "static jack/jack.h jack_port_get_buffer"
  port_get_buffer :: Ptr () -> CUInt -> IO (Ptr CFloat)

foreign import ccall "static jack/jack.h jack_get_buffer_size"
  get_buffer_size :: Ptr () -> IO (CUInt)

foreign import ccall "static jack/jack.h jack_activate"
  activate :: Ptr () -> IO (CInt)

foreign import ccall "static jack/jack.h jack_client_close"
  client_close :: Ptr () -> IO (CInt)

foreign import ccall "static jack/jack.h jack_get_ports"
  get_ports :: Ptr () -> Ptr (CChar) -> Ptr (CChar) -> CULong -> IO (Ptr (Ptr (CChar)))

foreign import ccall "static jack/jack.h jack_connect"
  connect :: Ptr () -> Ptr (CChar) -> Ptr (CChar) -> IO (CInt)

foreign import ccall "static jack/jack.h jack_port_unregister"
  port_unregister :: Ptr () -> Ptr () -> IO (CInt)

foreign import ccall "static jack/jack.h jack_deactivate"
  deactivate :: Ptr () -> IO (CInt)



-- * Utility functions

flagToWord :: (Enum a) => a -> CULong
flagToWord = bit . fromEnum

flagsToWord :: (Enum a) => [a] -> CULong
flagsToWord = foldl setBit 0 . map fromEnum

wordToFlags :: (Enum a) => CULong -> [a]
wordToFlags =
   map fst . filter (odd . snd) .
   zip [toEnum 0 ..] . iterate (flip div 2)