Files
scummvm-cursorfix/engines/ultima/nuvie/sound/midiparser_m.h
2026-02-02 04:50:13 +01:00

86 lines
2.8 KiB
C++

/* 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/>.
*
*/
#ifndef NUVIE_SOUND_MIDIPARSER_M_H
#define NUVIE_SOUND_MIDIPARSER_M_H
#include "audio/midiparser.h"
#include "common/stack.h"
#include "common/util.h"
namespace Ultima {
namespace Nuvie {
/**
* A parser for the music format M, used by Times Of Lore, Bad Blood and
* Ultima 6.
* This format is not really a MIDI format; it targets the OPL2 chip. However,
* it has several things in common with MIDI: it is a stream of events, it has
* note on and note off events and events similar to MIDI controllers, the high
* nibble of the first event byte is the command while the low nibble is
* usually the channel.
* The commands are different. M does not use the status byte / data byte
* convention and delta times are specified using a wait command. It uses
* channels 0-8, corresponding to the 9 OPL2 channels. OPL rhythm mode is not
* used.
*/
class MidiParser_M : public MidiParser {
protected:
struct LoopData {
byte numLoops;
const byte *startPos;
const byte *returnPos;
};
public:
MidiParser_M(int8 source = -1);
~MidiParser_M();
bool loadMusic(const byte *data, uint32 size) override;
void unloadMusic() override;
void onTimer() override;
protected:
bool processEvent(const EventInfo &info, bool fireEvents = true) override;
void parseNextEvent(EventInfo &info) override;
void allNotesOff() override;
uint32 _trackLength;
// The point in the MIDI data where the global loop (not using the stack)
// has started and will return.
const byte *_loopPoint;
// A stack of nested loops, similar to a call stack. A call command will
// specify an offset where the parser should jump to (startPus), plus a
// number of times the data from this offset up to the return command should
// be repeated (numLoops). Then the parser resumes with the command after
// the call command (returnPos). A maximum depth of 16 levels is supported.
Common::FixedStack<LoopData, 16> *_loopStack;
};
} // End of namespace Nuvie
} // End of namespace Ultima
#endif