aboutsummaryrefslogtreecommitdiff
path: root/sound/mods/paula.h
blob: aa3d5b4ab9e98ace5a9cc77dd9a7b36132ad6392 (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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
/* 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.
 *
 * $URL$
 * $Id$
 *
 */

#ifndef SOUND_MODS_PAULA_H
#define SOUND_MODS_PAULA_H

#include "sound/audiostream.h"
#include "common/frac.h"
#include "common/mutex.h"

namespace Audio {

/**
 * Emulation of the "Paula" Amiga music chip
 * The interrupt frequency specifies the number of mixed wavesamples between
 * calls of the interrupt method
 */
class Paula : public AudioStream {
public:
	static const int NUM_VOICES = 4;
	enum {
		kPalSystemClock  = 7093790,
		kNtscSystemClock = 7159090,
		kPalCiaClock     = kPalSystemClock / 10,
		kNtscCiaClock    = kNtscSystemClock / 10,
		kPalPaulaClock   = kPalSystemClock / 2,
		kNtscPauleClock  = kNtscSystemClock / 2
	};

	/* TODO: Document this */
	struct Offset {
		uint	int_off;	// integral part of the offset
		frac_t	rem_off;	// fractional part of the offset, at least 0 and less than 1

		explicit Offset(int off = 0) : int_off(off), rem_off(0) {}
	};

	Paula(bool stereo = false, int rate = 44100, uint interruptFreq = 0);
	~Paula();

	bool playing() const { return _playing; }
	void setTimerBaseValue( uint32 ticksPerSecond ) { _timerBase = ticksPerSecond; }
	uint32 getTimerBaseValue() { return _timerBase; }
	void setSingleInterrupt(uint sampleDelay) { assert(sampleDelay < _intFreq); _curInt = sampleDelay; }
	void setSingleInterruptUnscaled(uint timerDelay) {
		setSingleInterrupt((uint)(((double)timerDelay * getRate()) / _timerBase));
	}
	void setInterruptFreq(uint sampleDelay) { _intFreq = sampleDelay; _curInt = 0; }
	void setInterruptFreqUnscaled(uint timerDelay) {
		setInterruptFreq((uint)(((double)timerDelay * getRate()) / _timerBase));
	}
	void clearVoice(byte voice);
	void clearVoices() { for (int i = 0; i < NUM_VOICES; ++i) clearVoice(i); }
	void startPlay() { _playing = true; }
	void stopPlay() { _playing = false; }
	void pausePlay(bool pause) { _playing = !pause; }

// AudioStream API
	int readBuffer(int16 *buffer, const int numSamples);
	bool isStereo() const { return _stereo; }
	bool endOfData() const { return _end; }
	int getRate() const { return _rate; }

protected:
	struct Channel {
		const int8 *data;
		const int8 *dataRepeat;
		uint32 length;
		uint32 lengthRepeat;
		int16 period;
		byte volume;
		Offset offset;
		byte panning; // For stereo mixing: 0 = far left, 255 = far right
		int dmaCount;
	};

	bool _end;
	Common::Mutex _mutex;

	virtual void interrupt() = 0;

	void startPaula() {
		_playing = true;
		_end = false;
	}

	void stopPaula() {
		_playing = false;
		_end = true;
	}

	void setChannelPanning(byte channel, byte panning) {
		assert(channel < NUM_VOICES);
		_voice[channel].panning = panning;
	}

	void disableChannel(byte channel) {
		assert(channel < NUM_VOICES);
		_voice[channel].data = 0;
	}

	void enableChannel(byte channel) {
		assert(channel < NUM_VOICES);
		Channel &ch = _voice[channel];
		ch.data = ch.dataRepeat;
		ch.length = ch.lengthRepeat;
		// actually first 2 bytes are dropped?
		ch.offset = Offset(0);
		// ch.period = ch.periodRepeat;
	}

	void setChannelPeriod(byte channel, int16 period) {
		assert(channel < NUM_VOICES);
		_voice[channel].period = period;
	}

	void setChannelVolume(byte channel, byte volume) {
		assert(channel < NUM_VOICES);
		_voice[channel].volume = volume;
	}

	void setChannelSampleStart(byte channel, const int8 *data) {
		assert(channel < NUM_VOICES);
		_voice[channel].dataRepeat = data;
	}

	void setChannelSampleLen(byte channel, uint32 length) {
		assert(channel < NUM_VOICES);
		assert(length < 32768/2);
		_voice[channel].lengthRepeat = 2 * length;
	}

	void setChannelData(uint8 channel, const int8 *data, const int8 *dataRepeat, uint32 length, uint32 lengthRepeat, int32 offset = 0) {
		assert(channel < NUM_VOICES);

		Channel &ch = _voice[channel];

		ch.dataRepeat = data;
		ch.lengthRepeat = length;
		enableChannel(channel);
		ch.offset = Offset(offset);

		ch.dataRepeat = dataRepeat;
		ch.lengthRepeat = lengthRepeat;
	}

	void setChannelOffset(byte channel, Offset offset) {
		assert(channel < NUM_VOICES);
		_voice[channel].offset = offset;
	}

	Offset getChannelOffset(byte channel) {
		assert(channel < NUM_VOICES);
		return _voice[channel].offset;
	}

	int getChannelDmaCount(byte channel) {
		assert(channel < NUM_VOICES);
		return _voice[channel].dmaCount;
	}

	void setChannelDmaCount(byte channel, int dmaVal = 0) {
		assert(channel < NUM_VOICES);
		_voice[channel].dmaCount = dmaVal;
	}

	void setAudioFilter(bool enable) {
		// TODO: implement
	}

private:
	Channel _voice[NUM_VOICES];

	const bool _stereo;
	const int _rate;
	const double _periodScale;
	uint _intFreq;
	uint _curInt;
	uint32 _timerBase;
	bool _playing;

	template<bool stereo>
	int readBufferIntern(int16 *buffer, const int numSamples);
};

} // End of namespace Audio

#endif