aboutsummaryrefslogtreecommitdiff
path: root/engines/scumm/midiparser_ro.cpp
blob: c35876867d395b0402566c1ffface985ed17fdfb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/* 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 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.
 *
 */


#include "audio/midiparser.h"
#include "common/textconsole.h"

namespace Scumm {

//////////////////////////////////////////////////
//
// The Standard MIDI File version of MidiParser
//
//////////////////////////////////////////////////

class MidiParser_RO : public MidiParser {
protected:
	int _markerCount;     // Number of markers encountered in stream so far
	int _lastMarkerCount; // Cache markers until parsed event is actually consumed

protected:
	void compressToType0();
	void parseNextEvent (EventInfo &info);

public:
	bool loadMusic (byte *data, uint32 size);
	uint32 getTick() { return (uint32) _markerCount * _ppqn / 2; }
};



//////////////////////////////////////////////////
//
// MidiParser_RO implementation
//
//////////////////////////////////////////////////

void MidiParser_RO::parseNextEvent (EventInfo &info) {
	_markerCount += _lastMarkerCount;
	_lastMarkerCount = 0;

	info.delta = 0;
	do {
		info.start = _position._playPos;
		info.event = *(_position._playPos++);
		if (info.command() == 0xA) {
			++_lastMarkerCount;
			info.event = 0xF0;
		} else if (info.event == 0xF0 || info.event == 0xF1) {
			byte delay = *(_position._playPos++);
			info.delta += delay;
			if (info.event == 0xF1) {
				// This event is, as far as we have been able
				// to determine, only used in one single song
				// in EGA Loom. It seems to be meant for adding
				// values greater than 255 to info.delta. See
				// bug #1498785.
				info.delta += 256;
			}
			continue;
		}
		break;
	} while (true);

	// Seems to indicate EOT
	if (info.event == 0) {
		info.event = 0xFF;
		info.ext.type = 0x2F;
		info.length = 0;
		info.ext.data = 0;
		return;
	}

	if (info.event < 0x80)
		return;

	_position._runningStatus = info.event;
	switch (info.command()) {
	case 0xC:
		info.basic.param1 = *(_position._playPos++);
		info.basic.param2 = 0;
		break;

	case 0x8: case 0x9: case 0xB:
		info.basic.param1 = *(_position._playPos++);
		info.basic.param2 = *(_position._playPos++);
		if (info.command() == 0x9 && info.basic.param2 == 0)
			info.event = info.channel() | 0x80;
		info.length = 0;
		break;

	case 0xF: // Marker and EOT messages
		info.length = 0;
		info.ext.data = 0;
		if (info.event == 0xFF) {
			_autoLoop = true;
			info.ext.type = 0x2F;
		} else {
			info.ext.type = 0x7F; // Bogus META
		}
		info.event = 0xFF;
		break;

	default:
		break;
	}
}

bool MidiParser_RO::loadMusic (byte *data, uint32 size) {
	unloadMusic();
	byte *pos = data;

	if (memcmp (pos, "RO", 2)) {
		error("'RO' header expected but found '%c%c' instead", pos[0], pos[1]);
		return false;
	}

	_numTracks = 1;
	_ppqn = 120;
	_tracks[0] = pos + 2;
	_markerCount = _lastMarkerCount = 0;

	// 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;
}

MidiParser *MidiParser_createRO() { return new MidiParser_RO; }

} // End of namespace Scumm