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Diffstat (limited to 'sound/midiparser.cpp')
| -rw-r--r-- | sound/midiparser.cpp | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/sound/midiparser.cpp b/sound/midiparser.cpp new file mode 100644 index 0000000000..46eff182d7 --- /dev/null +++ b/sound/midiparser.cpp @@ -0,0 +1,207 @@ +/* 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. + * + * $Header$ + * + */ + +#include "midiparser.h" +#include "mididrv.h" +#include "common/util.h" + +#include <stdio.h> +#include <memory.h> + +////////////////////////////////////////////////// +// +// MidiParser implementation +// +////////////////////////////////////////////////// + +MidiParser::MidiParser() : +_driver (0), +_timer_rate (0x4A0000), +_ppqn (96), +_tempo (500000), +_psec_per_tick (5208), // 500000 / 96 +_autoLoop (false), +_num_tracks (0), +_active_track (255), +_play_pos (0), +_play_time (0), +_last_event_time (0), +_last_event_tick (0), +_running_status (0) +{ } + +void MidiParser::property (int prop, int value) { + switch (prop) { + case mpAutoLoop: + _autoLoop = (value != 0); + } +} + +// This is the conventional (i.e. SMF) variable length quantity +uint32 MidiParser::readVLQ (byte * &data) { + byte str; + uint32 value = 0; + int i; + + for (i = 0; i < 4; ++i) { + str = data[0]; + ++data; + value = (value << 7) | (str & 0x7F); + if (!(str & 0x80)) + break; + } + return value; +} + +void MidiParser::onTimer() { + uint32 end_time; + uint32 event_time; + + if (!_play_pos || !_driver) + return; + + end_time = _play_time + _timer_rate; + + while (true) { + EventInfo &info = _next_event; + + event_time = _last_event_time + info.delta * _psec_per_tick; + if (event_time > end_time) + break; + + // Process the next info. + _last_event_tick += info.delta; + if (info.event < 0x80) { + printf ("ERROR! Bad command or running status %02X", info.event); + _play_pos = 0; + return; + } + _running_status = info.event; + + if (info.event == 0xF0) { + // SysEx event + _driver->sysEx (info.data, (uint16) info.length); + } else if (info.event == 0xFF) { + // META event + if (info.type == 0x2F) { + // End of Track must be processed by us, + // as well as sending it to the output device. + allNotesOff(); + if (_autoLoop) { + _play_pos = _tracks[_active_track]; + parseNextEvent (_next_event); + } else { + _play_pos = 0; + _driver->metaEvent (info.type, info.data, (uint16) info.length); + } + return; + } else if (info.type == 0x51) { + if (info.length >= 3) { + _tempo = info.data[0] << 16 | info.data[1] << 8 | info.data[2]; + _psec_per_tick = (_tempo + (_ppqn >> 2)) / _ppqn; + } + } + _driver->metaEvent (info.type, info.data, (uint16) info.length); + } else { + _driver->send (info.event | info.param1 << 8 | info.param2 << 16); + } + + + _last_event_time = event_time; + parseNextEvent (_next_event); + } + + _play_time = end_time; +} + +void MidiParser::allNotesOff() { + if (!_driver) + return; + + int i; + for (i = 0; i < 15; ++i) { + _driver->send (0x007BB0 | i); + } +} + +void MidiParser::resetTracking() { + _play_pos = 0; + _tempo = 500000; + _psec_per_tick = 500000 / _ppqn; + _play_time = 0; + _last_event_time = 0; + _last_event_tick = 0; + _running_status = 0; +} + +void MidiParser::setTrack (byte track) { + if (track >= _num_tracks || track == _active_track) + return; + resetTracking(); + allNotesOff(); + _active_track = track; + _play_pos = _tracks[track]; + parseNextEvent (_next_event); +} + +void MidiParser::jumpToTick (uint32 tick) { + if (_active_track >= _num_tracks) + return; + resetTracking(); + allNotesOff(); + + _play_pos = _tracks[_active_track]; + parseNextEvent (_next_event); + if (tick == 0) + return; + + while (true) { + EventInfo &info = _next_event; + if (_last_event_tick + info.delta >= tick) { + _play_time += (tick - _last_event_tick) * _psec_per_tick; + break; + } + + _last_event_tick += info.delta; + _play_time += info.delta * _psec_per_tick; + _last_event_time = _play_time; + + if (info.event == 0xFF) { + if (info.type == 0x2F) { // End of track + if (_autoLoop) { + _play_pos = _tracks[_active_track]; + parseNextEvent (_next_event); + } else { + _play_pos = 0; + _driver->metaEvent (0x2F, info.data, (uint16) info.length); + } + break; + } else if (info.type == 0x51) { // Tempo + if (info.length >= 3) { + _tempo = info.data[0] << 16 | info.data[1] << 8 | info.data[2]; + _psec_per_tick = (_tempo + (_ppqn >> 2)) / _ppqn; + } + } + } + + parseNextEvent (_next_event); + } +} |