scummvm/backends/midi/coremidi.cpp

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

// Disable symbol overrides so that we can use system headers.
#define FORBIDDEN_SYMBOL_ALLOW_ALL

#include "common/scummsys.h"

#ifdef MACOSX

#include "common/config-manager.h"
#include "common/error.h"
#include "common/textconsole.h"
#include "common/util.h"
#include "audio/musicplugin.h"
#include "audio/mpu401.h"

#include <CoreMIDI/CoreMIDI.h>



/*
For information on how to unify the CoreMidi and MusicDevice code:

http://lists.apple.com/archives/Coreaudio-api/2005/Jun/msg00194.html
http://lists.apple.com/archives/coreaudio-api/2003/Mar/msg00248.html
http://lists.apple.com/archives/coreaudio-api/2003/Jul/msg00137.html

*/


/* CoreMIDI MIDI driver
 * By Max Horn
 */
class MidiDriver_CoreMIDI : public MidiDriver_MPU401 {
public:
	MidiDriver_CoreMIDI(ItemCount device);
	~MidiDriver_CoreMIDI();
	int open() override;
	bool isOpen() const override { return mOutPort != 0 && mDest != 0; }
	void close() override;
	void send(uint32 b) override;
	void sysEx(const byte *msg, uint16 length) override;

private:
	ItemCount mDevice;
	MIDIClientRef	mClient;
	MIDIPortRef		mOutPort;
	MIDIEndpointRef	mDest;
};

MidiDriver_CoreMIDI::MidiDriver_CoreMIDI(ItemCount device)
	: mDevice(device), mClient(0), mOutPort(0), mDest(0) {

	OSStatus err;
	err = MIDIClientCreate(CFSTR("ScummVM MIDI Driver for macOS"), NULL, NULL, &mClient);
}

MidiDriver_CoreMIDI::~MidiDriver_CoreMIDI() {
	if (mClient)
		MIDIClientDispose(mClient);
	mClient = 0;
}

int MidiDriver_CoreMIDI::open() {
	if (isOpen())
		return MERR_ALREADY_OPEN;

	OSStatus err = noErr;

	mOutPort = 0;

	ItemCount dests = MIDIGetNumberOfDestinations();
	if (mDevice < dests && mClient) {
		mDest = MIDIGetDestination(mDevice);
		err = MIDIOutputPortCreate( mClient,
									CFSTR("scummvm_output_port"),
									&mOutPort);
	} else {
		return MERR_DEVICE_NOT_AVAILABLE;
	}

	if (err != noErr)
		return MERR_CANNOT_CONNECT;

	return 0;
}

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

	if (isOpen()) {
		MIDIPortDispose(mOutPort);
		mOutPort = 0;
		mDest = 0;
	}
}

void MidiDriver_CoreMIDI::send(uint32 b) {
	assert(isOpen());

	midiDriverCommonSend(b);

	// Extract the MIDI data
	byte status_byte = (b & 0x000000FF);
	byte first_byte = (b & 0x0000FF00) >> 8;
	byte second_byte = (b & 0x00FF0000) >> 16;

	// Generate a single MIDI packet with that data
	MIDIPacketList packetList;
	MIDIPacket *packet = &packetList.packet[0];

	packetList.numPackets = 1;

	packet->timeStamp = 0;
	packet->data[0] = status_byte;
	packet->data[1] = first_byte;
	packet->data[2] = second_byte;

	// Compute the correct length of the MIDI command. This is important,
	// else things may screw up badly...
	switch (status_byte & 0xF0) {
	case 0x80:	// Note Off
	case 0x90:	// Note On
	case 0xA0:	// Polyphonic Aftertouch
	case 0xB0:	// Controller Change
	case 0xE0:	// Pitch Bending
		packet->length = 3;
		break;
	case 0xC0:	// Programm Change
	case 0xD0:	// Monophonic Aftertouch
		packet->length = 2;
		break;
	default:
		warning("CoreMIDI driver encountered unsupported status byte: 0x%02x", status_byte);
		packet->length = 3;
		break;
	}

	// Finally send it out to the synthesizer.
	MIDISend(mOutPort, mDest, &packetList);
}

void MidiDriver_CoreMIDI::sysEx(const byte *msg, uint16 length) {
	assert(isOpen());

	byte buf[384];
	MIDIPacketList *packetList = (MIDIPacketList *)buf;
	MIDIPacket *packet = packetList->packet;

	assert(sizeof(buf) >= sizeof(UInt32) + sizeof(MIDITimeStamp) + sizeof(UInt16) + length + 2);

	packetList->numPackets = 1;

	packet->timeStamp = 0;

	// Add SysEx frame
	packet->length = length + 2;
	packet->data[0] = 0xF0;
	memcpy(packet->data + 1, msg, length);
	packet->data[length + 1] = 0xF7;

	// Send it
	MIDISend(mOutPort, mDest, packetList);
}


// Plugin interface

class CoreMIDIMusicPlugin : public MusicPluginObject {
public:
	const char *getName() const {
		return "CoreMIDI";
	}

	const char *getId() const {
		return "coremidi";
	}

	MusicDevices getDevices() const;
	Common::Error createInstance(MidiDriver **mididriver, MidiDriver::DeviceHandle = 0) const;

private:
	bool getDeviceName(ItemCount deviceIndex, Common::String &outName) const;
};

MusicDevices CoreMIDIMusicPlugin::getDevices() const {
	// TODO: Is it possible to get the music type for each device?
	// Maybe look at the kMIDIPropertyModel property?

	MusicDevices devices;
	ItemCount deviceCount = MIDIGetNumberOfDestinations();
	for (ItemCount i = 0 ; i < deviceCount ; ++i) {
		Common::String name;
		if (getDeviceName(i, name))
			devices.push_back(MusicDevice(this, name, MT_GM));
	}
	return devices;
}

Common::Error CoreMIDIMusicPlugin::createInstance(MidiDriver **mididriver, MidiDriver::DeviceHandle device) const {
	ItemCount deviceCount = MIDIGetNumberOfDestinations();
	for (ItemCount i = 0 ; i < deviceCount ; ++i) {
		Common::String name;
		if (getDeviceName(i, name)) {
			MusicDevice md(this, name, MT_GM);
			if (md.getHandle() == device) {
				*mididriver = new MidiDriver_CoreMIDI(i);
				return Common::kNoError;
			}
		}
	}

	return Common::kUnknownError;
}

bool CoreMIDIMusicPlugin::getDeviceName(ItemCount deviceIndex, Common::String &outName) const {
	MIDIEndpointRef dest = MIDIGetDestination(deviceIndex);
	if (!dest)
		return false;
	CFStringRef name = nil;
	if (MIDIObjectGetStringProperty(dest, kMIDIPropertyDisplayName, &name) == noErr) {
		char buffer[128];
		if (CFStringGetCString(name, buffer, sizeof(buffer), kCFStringEncodingASCII)) {
			outName = buffer;
			CFRelease(name);
			return true;
		}
		CFRelease(name);
	}
	// Rather than fail use a default name
	warning("Failed to get name for CoreMIDi device %lu", deviceIndex);
	outName = Common::String::format("Unknown Device %lu", deviceIndex);
	return true;
}

//#if PLUGIN_ENABLED_DYNAMIC(COREMIDI)
	//REGISTER_PLUGIN_DYNAMIC(COREMIDI, PLUGIN_TYPE_MUSIC, CoreMIDIMusicPlugin);
//#else
	REGISTER_PLUGIN_STATIC(COREMIDI, PLUGIN_TYPE_MUSIC, CoreMIDIMusicPlugin);
//#endif

#endif // MACOSX