/* ScummVM - Scumm Interpreter
 * Copyright (C) 2001-2003 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header: /cvsroot/scummvm/scummvm/backends/midi/coreaudio.cpp,v 1.7 2003/07/02 23:24:05 fingolfin Exp $
 */

#ifdef MACOSX

#include "sound/mpu401.h"

#include <AudioUnit/AudioUnit.h>


// FIXME - the following disables reverb support in the QuickTime / CoreAudio
// midi backends. For some reasons, reverb will suck away a *lot* of CPU time.
// Until we know for sure what is causing this and if there is a better way to
// fix the problem, we just disable all reverb for these backends.
#define COREAUDIO_REVERB_HACK


/* CoreAudio MIDI driver
 * Based on code by Benjamin W. Zale
 * Extended by Max Horn
 */
class MidiDriver_CORE : public MidiDriver_MPU401 {
public:
	MidiDriver_CORE() : au_MusicDevice(0), au_output(0) { }
	int open();
	void close();
	void send(uint32 b);
	void sysEx(byte *msg, uint16 length);

private:
	AudioUnit au_MusicDevice;
	AudioUnit au_output;
};


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

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

	// Open the Music Device
	compdesc.componentType = kAudioUnitComponentType;
	compdesc.componentSubType = kAudioUnitSubType_MusicDevice;
	compdesc.componentManufacturer = kAudioUnitID_DLSSynth;
	compdesc.componentFlags = 0;
	compdesc.componentFlagsMask = 0;
	compid = FindNextComponent(NULL, &compdesc);
	au_MusicDevice = (AudioUnit) OpenComponent(compid);

	// open the output unit
	au_output = (AudioUnit) OpenDefaultComponent(kAudioUnitComponentType, kAudioUnitSubType_Output);

	// 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));

	// 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);
	CloseComponent(au_MusicDevice);
}

void MidiDriver_CORE::send(uint32 b) {
	unsigned char first_byte, second_byte, status_byte;
	status_byte = (b & 0x000000FF);
	first_byte = (b & 0x0000FF00) >> 8;
	second_byte = (b & 0x00FF0000) >> 16;

#ifdef COREAUDIO_REVERB_HACK
	if ((status_byte&0xF0) == 0xB0 && first_byte == 0x5b)
		return;
#endif

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

void MidiDriver_CORE::sysEx(byte *msg, uint16 length) {
	MusicDeviceSysEx(au_MusicDevice, msg, length);
}

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

#endif // MACOSX
