scummvm/scumm/instrument.h

/* ScummVM - Scumm Interpreter
 * Copyright (C) 2001  Ludvig Strigeus
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 */

#ifndef INSTRUMENT_H
#define INSTRUMENT_H

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

class MidiChannel;

namespace Scumm {

class Serializer;
class Instrument;

class InstrumentInternal {
public:
	virtual void saveOrLoad (Serializer *s) = 0;
	virtual void send (MidiChannel *mc) = 0;
	virtual void copy_to (Instrument *dest) = 0;
	virtual bool is_valid() = 0;
	virtual operator int() { return 255; }
};

class Instrument {
private:
	byte _type;
	InstrumentInternal *_instrument;

public:
	enum {
		itNone = 0,
		itProgram = 1,
		itAdlib = 2,
		itRoland = 3
	};

	Instrument() : _type (0), _instrument (0) { }
	~Instrument() { delete _instrument; }
	static void nativeMT32 (bool native);

	void clear();
	void copy_to (Instrument *dest) { if (_instrument) _instrument->copy_to (dest); else dest->clear(); }

	// FIXME: This is evil! We cast a pointer to an int. Besides not being
	// portable to 64bit systems, it is unclear why this is needed.
	// If the only reason is to supply a unique identifier of that
	// instrument: there are better ways do do that.
	// OTOH, maybe the code is simply wrong, and what is really meant
	// here is to first dereference _instrument, then cast it? Like
	// this: (int)*_instrument
	// At least this would explain the otherwise unused operator int()
	// supplied by class Instrument_Program.
	// If that is the case, the operator int() should all be replaced by
	// a proper method, like "get_something()"
	operator int() { return (_instrument ? (int) _instrument : 255); }

	void program (byte program, bool mt32);
	void adlib (byte *instrument);
	void roland (byte *instrument);

	byte getType() { return _type; }
	bool isValid() { return (_instrument ? _instrument->is_valid() : false); }
	void saveOrLoad (Serializer *s);
	void send (MidiChannel *mc) { if (_instrument) _instrument->send (mc); }
};

} // End of namespace Scumm

#endif