diff options
Diffstat (limited to 'engines/agos/midiparser_s1d.cpp')
| -rw-r--r-- | engines/agos/midiparser_s1d.cpp | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/engines/agos/midiparser_s1d.cpp b/engines/agos/midiparser_s1d.cpp new file mode 100644 index 0000000000..2b58c9ffa1 --- /dev/null +++ b/engines/agos/midiparser_s1d.cpp @@ -0,0 +1,155 @@ +/* ScummVM - Scumm Interpreter + * Copyright (C) 2001 Ludvig Strigeus + * Copyright (C) 2001-2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * $URL$ + * $Id$ + * + */ + +#include "common/stdafx.h" + +#include "common/util.h" + +#include "sound/mididrv.h" +#include "sound/midiparser.h" + +#include <stdio.h> + +namespace Simon { + +/** + * Simon 1 Demo version of MidiParser. + * + * This parser is the result of eyeballing the one MUS file that's included + * with simon1demo. So there might be some things missing. I've tried to notate + * question-mark areas where they occur. + */ +class MidiParser_S1D : public MidiParser { +protected: + byte *_data; + bool _no_delta; + +protected: + void parseNextEvent (EventInfo &info); + void resetTracking(); + uint32 readVLQ2(byte * &data); + +public: + MidiParser_S1D() : _data(0), _no_delta(false) {} + + bool loadMusic(byte *data, uint32 size); +}; + + +// The VLQs for simon1demo seem to be +// in Little Endian format. +uint32 MidiParser_S1D::readVLQ2(byte * &data) { + byte str; + uint32 value = 0; + int i; + + for (i = 0; i < 4; ++i) { + str = data[0]; + ++data; + value |= (str & 0x7F) << (i * 7); + if (!(str & 0x80)) + break; + } + return value; +} + +void MidiParser_S1D::parseNextEvent(EventInfo &info) { + info.start = _position._play_pos; + info.delta = _no_delta ? 0 : readVLQ2(_position._play_pos); + + _no_delta = false; + info.event = *(_position._play_pos++); + if (info.command() < 0x8) { + _no_delta = true; + info.event += 0x80; + } + + switch (info.command()) { + case 0x8: + info.basic.param1 = *(_position._play_pos++); + info.basic.param2 = 0; + info.length = 0; + break; + + case 0x9: + info.basic.param1 = *(_position._play_pos++); + info.basic.param2 = *(_position._play_pos++); // I'm ASSUMING this byte is velocity! + info.length = 0; + break; + + case 0xC: + info.basic.param1 = *(_position._play_pos++); + info.basic.param2 = 0; + ++_position._play_pos; // I have NO IDEA what the second byte is for. + break; + + case 0xF: + if (info.event == 0xFC) { + // This means End of Track. + // Rewrite in SMF (MIDI transmission) form. + info.event = 0xFF; + info.ext.type = 0x2F; + info.length = 0; + break; + } + // OTherwise fall through to default. + + default: + debug(3, "MidiParser_S1D: Unexpected byte 0x%02X found", (int) info.command()); + break; + } +} + +bool MidiParser_S1D::loadMusic(byte *data, uint32 size) { + unloadMusic(); + + byte *pos = data; + if (*(pos++) != 0xFC) + error("Expected 0xFC header but found 0x%02X instead", (int) *pos); + + // The next 3 bytes MIGHT be tempo, but we skip them and use the default. +// setTempo (*(pos++) | (*(pos++) << 8) | (*(pos++) << 16)); + pos += 3; + + // And now we're at the actual data. Only one track. + _num_tracks = 1; + _data = pos; + _tracks[0] = pos; + + // Note that we assume the original data passed in + // will persist beyond this call, i.e. we do NOT + // copy the data to our own buffer. Take warning.... + resetTracking(); + setTempo(666667); + setTrack(0); + return true; +} + +void MidiParser_S1D::resetTracking() { + MidiParser::resetTracking(); + _no_delta = false; +} + +MidiParser *MidiParser_createS1D() { return new MidiParser_S1D; } + +} // End of namespace Simon |