scummvm/backends/midi/coreaudio.cpp

/* ScummVM - Scumm Interpreter
 * Copyright (C) 2001-2005 The ScummVM project
 *
 * 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.
 *
 * $Header$
 */

#ifdef MACOSX

#include "common/stdafx.h"
#include "common/config-manager.h"
#include "common/util.h"
#include "sound/mpu401.h"

#include <AudioUnit/AudioUnit.h>



// Activating the following switch disables reverb support in the CoreAudio
// midi backend. Reverb will suck away a *lot* of CPU time, so on slower
// systems, you may want to turn it off completely.
// TODO: Maybe make this a config option?
//#define COREAUDIO_DISABLE_REVERB

/*
See here to see how to react to a change of the default output unit:
http://cvs.opendarwin.org/cgi-bin/cvsweb.cgi/proj/KDE-Darwin/arts/flow/audioiocoreaudio.cc?rev=HEAD&content-type=text/x-cvsweb-markup

*/


/* CoreAudio MIDI driver
 * Based on code by Benjamin W. Zale
 * Extended by Max Horn
 */
class MidiDriver_CORE : public MidiDriver_MPU401 {
public:
	MidiDriver_CORE();
	int open();
	void close();
	void send(uint32 b);
	void sysEx(byte *msg, uint16 length);

private:
	AudioUnit au_MusicDevice;
	AudioUnit au_output;
};

MidiDriver_CORE::MidiDriver_CORE()
	: au_MusicDevice(0), au_output(0) {
}

int MidiDriver_CORE::open() {
	if (au_output)
		return MERR_ALREADY_OPEN;

	AudioUnitConnection auconnect;
	ComponentDescription compdesc;
	Component compid;
	OSErr err;

	// Open the Music Device.
	// We use the AudioUnit v1 API, even though it is deprecated, because
	// this way we stay compatible with older OS X versions.
	// For v2, we'd use kAudioUnitType_MusicDevice and kAudioUnitSubType_DLSSynth
	compdesc.componentType = kAudioUnitComponentType;
	compdesc.componentSubType = kAudioUnitSubType_MusicDevice;
	compdesc.componentManufacturer = kAudioUnitID_DLSSynth;
	compdesc.componentFlags = 0;
	compdesc.componentFlagsMask = 0;
	compid = FindNextComponent(NULL, &compdesc);
	au_MusicDevice = static_cast<AudioUnit>(OpenComponent(compid));

	if (au_MusicDevice == 0)
		error("Failed opening CoreAudio music device");

	// Load custom soundfont, if specified
	// FIXME: This is kind of a temporary hack. Better (IMO) would be to
	// query QuickTime for whatever custom soundfont was set in the
	// QuickTime Preferences, and use that automatically.
	if (ConfMan.hasKey("soundfont")) {
		FSRef	fsref;
		FSSpec	fsSpec;
		const char *soundfont = ConfMan.get("soundfont").c_str();

		err = FSPathMakeRef ((const byte *)soundfont, &fsref, NULL);

		if (err == noErr) {
			err = FSGetCatalogInfo (&fsref, kFSCatInfoNone, NULL, NULL, &fsSpec, NULL);
		}

		if (err == noErr) {
			err = AudioUnitSetProperty (
				au_MusicDevice,
				kMusicDeviceProperty_SoundBankFSSpec, kAudioUnitScope_Global,
				0,
				&fsSpec, sizeof(fsSpec)
			);
		}

		if (err != noErr)
			warning("Failed loading custom sound font '%s' (error %d)\n", soundfont, err);
	}

	// open the output unit
	au_output = (AudioUnit) OpenDefaultComponent(kAudioUnitComponentType, kAudioUnitSubType_Output);
	if (au_output == 0)
		error("Failed opening output audio unit");

	// connect the units
	auconnect.sourceAudioUnit = au_MusicDevice;
	auconnect.sourceOutputNumber = 0;
	auconnect.destInputNumber = 0;
	err =
		AudioUnitSetProperty(au_output, kAudioUnitProperty_MakeConnection, kAudioUnitScope_Input, 0,
												 (void *)&auconnect, sizeof(AudioUnitConnection));

#ifdef COREAUDIO_DISABLE_REVERB
	UInt32 usesReverb = 0;
	AudioUnitSetProperty (au_MusicDevice, kMusicDeviceProperty_UsesInternalReverb,
		kAudioUnitScope_Global,    0, &usesReverb, sizeof (usesReverb));
#endif

	// initialize the units
	AudioUnitInitialize(au_MusicDevice);
	AudioUnitInitialize(au_output);

	// start the output
	AudioOutputUnitStart(au_output);


	return 0;
}

void MidiDriver_CORE::close() {
	MidiDriver_MPU401::close();

	// Stop the output
	AudioOutputUnitStop(au_output);

	// Cleanup
	CloseComponent(au_output);
	au_output = 0;
	CloseComponent(au_MusicDevice);
	au_MusicDevice = 0;
}

void MidiDriver_CORE::send(uint32 b) {
	assert(au_output != NULL);
	assert(au_MusicDevice != NULL);

	byte status_byte = (b & 0x000000FF);
	byte first_byte = (b & 0x0000FF00) >> 8;
	byte second_byte = (b & 0x00FF0000) >> 16;

	MusicDeviceMIDIEvent(au_MusicDevice, status_byte, first_byte, second_byte, 0);
}

void MidiDriver_CORE::sysEx(byte *msg, uint16 length) {
	assert(au_output != NULL);
	assert(au_MusicDevice != NULL);

	// Add SysEx frame if missing
	byte *buf = 0;
	if (*msg != 0xF0) {
		buf = (byte *)malloc(length + 2);
		buf[0] = 0xF0;
		memcpy(buf+1, msg, length);
		buf[length+1] = 0xF7;
		msg = buf;
		length += 2;
	}

	MusicDeviceSysEx(au_MusicDevice, msg, length);

	free(buf);
}

MidiDriver *MidiDriver_CORE_create() {
	return new MidiDriver_CORE();
}

#endif // MACOSX