scummvm/sound/mididrv.h

/* 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 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.
 *
 * $URL$
 * $Id$
 *
 */

#ifndef SOUND_MIDIDRV_H
#define SOUND_MIDIDRV_H

#include "common/scummsys.h"
#include "common/timer.h"

class MidiChannel;
class MusicDevice;

namespace Audio {
	class Mixer;
}
namespace Common { class String; }

/**
 * Music Driver Types, used to uniquely identify each music driver.
 *
 * The pseudo drivers are listed first, then all native drivers,
 * then all other MIDI drivers, and finally the non-MIDI drivers.
 *
 * @todo Rename MidiDriverType to MusicDriverType
 */

/**
 * Music types that music drivers can implement and engines can rely on.
 */
enum MusicType {
	MT_INVALID = -1,    // Invalid output
	MT_AUTO = 0,        // Auto
	MT_NULL,            // Null
	MT_PCSPK,           // PC Speaker
	MT_PCJR,            // PCjr
	MT_CMS,             // CMS
	MT_ADLIB,           // AdLib
	MT_TOWNS,           // FM-TOWNS
	MT_PC98,            // PC98
	MT_GM,              // General MIDI
	MT_MT32,            // MT-32
	MT_GS               // Roland GS
};

/**
 * A set of flags to be passed to detectDevice() which can be used to
 * specify what kind of music driver is preferred / accepted.
 *
 * The flags (except for MDT_PREFER_MT32 and MDT_PREFER_GM) indicate whether a given driver
 * type is acceptable. E.g. the TOWNS music driver could be returned by
 * detectDevice if and only if MDT_TOWNS is specified.
 *
 * @todo Rename MidiDriverFlags to MusicDriverFlags
 */
enum MidiDriverFlags {
	MDT_NONE   = 0,
	MDT_PCSPK  = 1 << 0,      // PC Speaker: Maps to MD_PCSPK and MD_PCJR
	MDT_CMS    = 1 << 1,      // Creative Music System / Gameblaster: Maps to MD_CMS
	MDT_PCJR   = 1 << 2,      // Tandy/PC Junior driver
	MDT_ADLIB  = 1 << 3,      // AdLib: Maps to MT_ADLIB
	MDT_TOWNS  = 1 << 4,      // FM-TOWNS: Maps to MT_TOWNS
	MDT_PC98   = 1 << 5,      // FM-TOWNS: Maps to MT_PC98
	MDT_MIDI   = 1 << 6,      // Real MIDI
	MDT_PREFER_MT32 = 1 << 7, // MT-32 output is preferred
	MDT_PREFER_GM = 1 << 8    // GM output is preferred
};

/**
 * Abstract description of a MIDI driver. Used by the config file and command
 * line parsing code, and also to be able to give the user a list of available
 * drivers.
 *
 * @todo Rename MidiDriverType to MusicDriverType
 */

/**
 * Abstract MIDI Driver Class
 *
 * @todo Rename MidiDriver to MusicDriver
 */
class MidiDriver {
public:
	/**
	 * The device handle.
	 *
	 * The value 0 is reserved for an invalid device for now.
	 * TODO: Maybe we should use -1 (i.e. 0xFFFFFFFF) as
	 * invalid device?
	 */
	typedef uint32 DeviceHandle;

	enum DeviceStringType {
		kDriverName,
		kDriverId,
		kDeviceId
	};

	static uint32 musicType2GUIO(uint32 musicType);

	/** Create music driver matching the given device handle, or NULL if there is no match. */
	static MidiDriver *createMidi(DeviceHandle handle);

	/** Returns device handle based on the present devices and the flags parameter. */
	static DeviceHandle detectDevice(int flags);

	/** Find the music driver matching the given driver name/description. */
	static DeviceHandle getDeviceHandle(const Common::String &identifier);

	/** Get the music type matching the given device handle, or MT_AUTO if there is no match. */
	static MusicType getMusicType(DeviceHandle handle);

	/** Get the device description string matching the given device handle and the given type. */
	static Common::String getDeviceString(DeviceHandle handle, DeviceStringType type);

private:
	// If detectDevice() detects MT32 and we have a preferred MT32 device
	// we use this to force getMusicType() to return MT_MT32 so that we don't
	// have to rely on the 'True Roland MT-32' config manager setting (since nobody
	// would possibly think about activating 'True Roland MT-32' when he has set
	// 'Music Driver' to '<default>')
	static bool _forceTypeMT32;

public:
	virtual ~MidiDriver() { }

	static const byte _mt32ToGm[128];
	static const byte _gmToMt32[128];

	/**
	 * Error codes returned by open.
	 * Can be converted to a string with getErrorName().
	 */
	enum {
		MERR_CANNOT_CONNECT = 1,
//		MERR_STREAMING_NOT_AVAILABLE = 2,
		MERR_DEVICE_NOT_AVAILABLE = 3,
		MERR_ALREADY_OPEN = 4
	};

	enum {
//		PROP_TIMEDIV = 1,
		PROP_OLD_ADLIB = 2,
		PROP_CHANNEL_MASK = 3
	};

	/**
	 * Open the midi driver.
	 * @return 0 if successful, otherwise an error code.
	 */
	virtual int open() = 0;

	/** Close the midi driver. */
	virtual void close() = 0;

	/**
	 * Output a packed midi command to the midi stream.
	 * The 'lowest' byte (i.e. b & 0xFF) is the status
	 * code, then come (if used) the first and second
	 * opcode.
	 */
	virtual void send(uint32 b) = 0;

	/**
	 * Output a midi command to the midi stream. Convenience wrapper
	 * around the usual 'packed' send method.
	 *
	 * Do NOT use this for sysEx transmission; instead, use the sysEx()
	 * method below.
	 */
	void send(byte status, byte firstOp, byte secondOp) {
		send(status | ((uint32)firstOp << 8) | ((uint32)secondOp << 16));
	}

	/** Get or set a property. */
	virtual uint32 property(int prop, uint32 param) { return 0; }

	/** Retrieve a string representation of an error code. */
	static const char *getErrorName(int error_code);

	// HIGH-LEVEL SEMANTIC METHODS
	virtual void setPitchBendRange(byte channel, uint range) {
		send(0xB0 | channel, 101, 0);
		send(0xB0 | channel, 100, 0);
		send(0xB0 | channel,   6, range);
		send(0xB0 | channel,  38, 0);
		send(0xB0 | channel, 101, 127);
		send(0xB0 | channel, 100, 127);
	}

	/**
	 * Transmit a sysEx to the midi device.
	 *
	 * The given msg MUST NOT contain the usual SysEx frame, i.e.
	 * do NOT include the leading 0xF0 and the trailing 0xF7.
	 *
	 * Furthermore, the maximal supported length of a SysEx
	 * is 264 bytes. Passing longer buffers can lead to
	 * undefined behavior (most likely, a crash).
	 */
	virtual void sysEx(const byte *msg, uint16 length) { }

	virtual void sysEx_customInstrument(byte channel, uint32 type, const byte *instr) { }

	virtual void metaEvent(byte type, byte *data, uint16 length) { }

	// Timing functions - MidiDriver now operates timers
	virtual void setTimerCallback(void *timer_param, Common::TimerManager::TimerProc timer_proc) = 0;

	/** The time in microseconds between invocations of the timer callback. */
	virtual uint32 getBaseTempo() = 0;

	// Channel allocation functions
	virtual MidiChannel *allocateChannel() = 0;
	virtual MidiChannel *getPercussionChannel() = 0;
};

class MidiChannel {
public:
	virtual ~MidiChannel() {}

	virtual MidiDriver *device() = 0;
	virtual byte getNumber() = 0;
	virtual void release() = 0;

	virtual void send(uint32 b) = 0; // 4-bit channel portion is ignored

	// Regular messages
	virtual void noteOff(byte note) = 0;
	virtual void noteOn(byte note, byte velocity) = 0;
	virtual void programChange(byte program) = 0;
	virtual void pitchBend(int16 bend) = 0; // -0x2000 to +0x1FFF

	// Control Change messages
	virtual void controlChange(byte control, byte value) = 0;
	virtual void modulationWheel(byte value) { controlChange(1, value); }
	virtual void volume(byte value) { controlChange(7, value); }
	virtual void panPosition(byte value) { controlChange(10, value); }
	virtual void pitchBendFactor(byte value) = 0;
	virtual void detune(byte value) { controlChange(17, value); }
	virtual void priority(byte value) { }
	virtual void sustain(bool value) { controlChange(64, value ? 1 : 0); }
	virtual void effectLevel(byte value) { controlChange(91, value); }
	virtual void chorusLevel(byte value) { controlChange(93, value); }
	virtual void allNotesOff() { controlChange(123, 0); }

	// SysEx messages
	virtual void sysEx_customInstrument(uint32 type, const byte *instr) = 0;
};

#endif