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/* 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 "sound/midiparser.h"
#include "sound/mididrv.h"
#include "common/util.h"
#include <stdio.h>
#include <memory.h>
//////////////////////////////////////////////////
//
// Simon 1 Demo version of MidiParser
//
//////////////////////////////////////////////////
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);
};
//////////////////////////////////////////////////
//
// MidiParser_S1D implementation
//
// 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.
//
//////////////////////////////////////////////////
// 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:
printf ("MidiParser_S1D: Warning! Unexpected byte 0x%02X found!\n", (int) info.event);
_abort_parse = true;
_position._play_pos = 0;
}
}
bool MidiParser_S1D::loadMusic (byte *data, uint32 size) {
unloadMusic();
byte *pos = data;
if (*(pos++) != 0xFC) {
printf ("Warning: Expected 0xFC header but found 0x%02X instead\n", (int) *pos);
return false;
}
// 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 (500000);
setTrack (0);
return true;
}
void MidiParser_S1D::resetTracking() {
MidiParser::resetTracking();
_no_delta = false;
}
MidiParser *MidiParser_createS1D() { return new MidiParser_S1D; }
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