/*

native_midi_macosx: Native Midi support on Mac OS X for the SDL_mixer library

Copyright (C) 2009 Ryan C. Gordon

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 of the License, or (at your option) any later version.

This library 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Ryan C. Gordon

icculus@icculus.org

*/

/* This is Mac OS X only, using Core MIDI.

Mac OS 9 support via QuickTime is in native_midi_mac.c */

#include "SDL_config.h"

#if __MACOSX__

#include <AudioToolbox/AudioToolbox.h>

#include "SDL_endian.h"

#include "native_midi.h"

/* Native Midi song */

struct _NativeMidiSong

{

MusicPlayer player;

MusicSequence sequence;

MusicTimeStamp endTime;

};

static NativeMidiSong *currentsong = NULL;

static OSStatus

GetSequenceLength(MusicSequence sequence, MusicTimeStamp *_sequenceLength)

{

// http://lists.apple.com/archives/Coreaudio-api/2003/Jul/msg00370.html

// figure out sequence length

UInt32 ntracks, i;

MusicTimeStamp sequenceLength = 0;

OSStatus err;

err = MusicSequenceGetTrackCount(sequence, &ntracks);

if (err != noErr)

return err;

for (i = 0; i < ntracks; ++i)

{

MusicTrack track;

MusicTimeStamp tracklen = 0;

UInt32 tracklenlen = sizeof (tracklen);

err = MusicSequenceGetIndTrack(sequence, i, &track);

if (err != noErr)

return err;

err = MusicTrackGetProperty(track, kSequenceTrackProperty_TrackLength,

&tracklen, &tracklenlen);

if (err != noErr)

return err;

if (sequenceLength < tracklen)

sequenceLength = tracklen;

}

*_sequenceLength = sequenceLength;

return noErr;

}

/* we're looking for the sequence output audiounit. */

static OSStatus

GetSequenceAudioUnit(MusicSequence sequence, AudioUnit *aunit)

{

AUGraph graph;

UInt32 nodecount, i;

OSStatus err;

err = MusicSequenceGetAUGraph(sequence, &graph);

if (err != noErr)

return err;

err = AUGraphGetNodeCount(graph, &nodecount);

if (err != noErr)

return err;

for (i = 0; i < nodecount; i++) {

AUNode node;

if (AUGraphGetIndNode(graph, i, &node) != noErr)

continue; /* better luck next time. */

#if 1 /* this is deprecated, but works back to 10.0 */

{

struct ComponentDescription desc;

UInt32 classdatasize = 0;

void *classdata = NULL;

err = AUGraphGetNodeInfo(graph, node, &desc, &classdatasize,

&classdata, aunit);

if (err != noErr)

continue;

else if (desc.componentType != kAudioUnitType_Output)

continue;

else if (desc.componentSubType != kAudioUnitSubType_DefaultOutput)

continue;

}

#else /* not deprecated, but requires 10.5 or later */

{

AudioComponentDescription desc;

if (AUGraphNodeInfo(graph, node, &desc, aunit) != noErr)

continue;

else if (desc.componentType != kAudioUnitType_Output)

continue;

else if (desc.componentSubType != kAudioUnitSubType_DefaultOutput)

continue;

}

#endif

return noErr; /* found it! */

}

return kAUGraphErr_NodeNotFound;

}

int native_midi_detect()

{

return 1; /* always available. */

}

NativeMidiSong *native_midi_loadsong(const char *midifile)

{

NativeMidiSong *retval = NULL;

SDL_RWops *rw = SDL_RWFromFile(midifile, "rb");

if (rw != NULL) {

retval = native_midi_loadsong_RW(rw);

SDL_RWclose(rw);

}

return retval;

}

NativeMidiSong *native_midi_loadsong_RW(SDL_RWops *rw)

{

NativeMidiSong *retval = NULL;

void *buf = NULL;

int len = 0;

CFDataRef data = NULL;

if (SDL_RWseek(rw, 0, RW_SEEK_END) < 0)

goto fail;

len = SDL_RWtell(rw);

if (len < 0)

goto fail;

if (SDL_RWseek(rw, 0, RW_SEEK_SET) < 0)

goto fail;

buf = malloc(len);

if (buf == NULL)

goto fail;

if (SDL_RWread(rw, buf, len, 1) != 1)

goto fail;

retval = malloc(sizeof(NativeMidiSong));

if (retval == NULL)

goto fail;

memset(retval, '\0', sizeof (*retval));

if (NewMusicPlayer(&retval->player) != noErr)

goto fail;

if (NewMusicSequence(&retval->sequence) != noErr)

goto fail;

data = CFDataCreate(NULL, (const UInt8 *) buf, len);

if (data == NULL)

goto fail;

free(buf);

buf = NULL;

#if 1 /* this is deprecated, but works back to 10.3 */

if (MusicSequenceLoadSMFDataWithFlags(retval->sequence, data, 0) != noErr)

goto fail;

#else /* not deprecated, but requires 10.5 or later */

if (MusicSequenceLoadData(retval->sequence, data, 0, 0) != noErr)

goto fail;

#endif

CFRelease(data);

data = NULL;

if (GetSequenceLength(retval->sequence, &retval->endTime) != noErr)

goto fail;

if (MusicPlayerSetSequence(retval->player, retval->sequence) != noErr)

goto fail;

return retval;

fail:

if (retval) {

if (retval->sequence)

DisposeMusicSequence(retval->sequence);

if (retval->player)

DisposeMusicPlayer(retval->player);

free(retval);

}

if (data)

CFRelease(data);

if (buf)

free(buf);

return NULL;

}

void native_midi_freesong(NativeMidiSong *song)

{

if (song != NULL) {

if (currentsong == song)

currentsong = NULL;

MusicPlayerStop(song->player);

DisposeMusicSequence(song->sequence);

DisposeMusicPlayer(song->player);

free(song);

}

}

void native_midi_start(NativeMidiSong *song)

{

int vol;

if (song == NULL)

return;

SDL_PauseAudio(1);

SDL_UnlockAudio();

if (currentsong)

MusicPlayerStop(currentsong->player);

currentsong = song;

MusicPlayerStart(song->player);

GetSequenceAudioUnit(song->sequence, &song->audiounit);

vol = latched_volume;

latched_volume++; /* just make this not match. */

native_midi_setvolume(vol);

SDL_LockAudio();

SDL_PauseAudio(0);

}

void native_midi_stop()

{

if (currentsong) {

SDL_PauseAudio(1);

SDL_UnlockAudio();

MusicPlayerStop(currentsong->player);

currentsong = NULL;

SDL_LockAudio();

SDL_PauseAudio(0);

}

}

int native_midi_active()

{

MusicTimeStamp currentTime = 0;

if (currentsong == NULL)

return 0;

MusicPlayerGetTime(currentsong->player, &currentTime);

return ((currentTime < currentsong->endTime) ||

(currentTime >= kMusicTimeStamp_EndOfTrack));

}

void native_midi_setvolume(int volume)

{

if (latched_volume == volume)

return;

latched_volume = volume;

if ((currentsong) && (currentsong->audiounit)) {

const float floatvol = ((float) volume) / ((float) MIX_MAX_VOLUME);

AudioUnitSetParameter(currentsong->audiounit, kHALOutputParam_Volume,

kAudioUnitScope_Global, 0, floatvol, 0);

}

}

const char *native_midi_error(void)

{

return ""; /* !!! FIXME */

}

#endif /* Mac OS X native MIDI support */