aboutsummaryrefslogtreecommitdiff
path: root/engines/scumm/players/player_v2.cpp
blob: f0aaa4a3beccc41aa4ef053601d1df7896081c72 (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
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
/* 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 "scumm/players/player_v2.h"
#include "scumm/scumm.h"

namespace Scumm {

#define SPK_DECAY   0xa000              /* Depends on sample rate */
#define PCJR_DECAY  0xa000              /* Depends on sample rate */

#define NG_PRESET 0x0f35        /* noise generator preset */
#define FB_WNOISE 0x12000       /* feedback for white noise */
#define FB_PNOISE 0x08000       /* feedback for periodic noise */


Player_V2::Player_V2(ScummEngine *scumm, Audio::Mixer *mixer, bool pcjr)
	: Player_V2Base(scumm, mixer, pcjr) {

	int i;

	// Initialize square generator
	_level = 0;

	_RNG = NG_PRESET;

	_pcjr = pcjr;

	if (_pcjr) {
		_decay = PCJR_DECAY;
		_update_step = (_sampleRate << FIXP_SHIFT) / (111860 * 2);
	} else {
		_decay = SPK_DECAY;
		_update_step = (_sampleRate << FIXP_SHIFT) / (1193000 * 2);
	}

	// Adapt _decay to sample rate.  It must be squared when
	// sample rate doubles.
	for (i = 0; (_sampleRate << i) < 30000; i++)
		_decay = _decay * _decay / 65536;

	_timer_output = 0;
	for (i = 0; i < 4; i++)
		_timer_count[i] = 0;

	setMusicVolume(255);

	_mixer->playStream(Audio::Mixer::kPlainSoundType, &_soundHandle, this, -1, Audio::Mixer::kMaxChannelVolume, 0, DisposeAfterUse::NO, true);
}

Player_V2::~Player_V2() {
	Common::StackLock lock(_mutex);
	_mixer->stopHandle(_soundHandle);
}

void Player_V2::setMusicVolume (int vol) {
	if (vol > 255)
		vol = 255;

	/* scale to int16, FIXME: find best value */
	double out = vol * 128 / 3;

	/* build volume table (2dB per step) */
	for (int i = 0; i < 15; i++) {
		/* limit volume to avoid clipping */
		if (out > 0xffff)
			_volumetable[i] = 0xffff;
		else
			_volumetable[i] = (int) out;

		out /= 1.258925412;         /* = 10 ^ (2/20) = 2dB */
	}
	_volumetable[15] = 0;
}

void Player_V2::stopAllSounds() {
	Common::StackLock lock(_mutex);

	for (int i = 0; i < 4; i++) {
		clear_channel(i);
	}
	_next_nr = _current_nr = 0;
	_next_data = _current_data = 0;
}

void Player_V2::stopSound(int nr) {
	Common::StackLock lock(_mutex);

	if (_next_nr == nr) {
		_next_nr = 0;
		_next_data = 0;
	}
	if (_current_nr == nr) {
		for (int i = 0; i < 4; i++) {
			clear_channel(i);
		}
		_current_nr = 0;
		_current_data = 0;
		chainNextSound();
	}
}

void Player_V2::startSound(int nr) {
	Common::StackLock lock(_mutex);

	byte *data = _vm->getResourceAddress(rtSound, nr);
	assert(data);

	int cprio = _current_data ? *(_current_data + _header_len) : 0;
	int prio  = *(data + _header_len);
	int nprio = _next_data ? *(_next_data + _header_len) : 0;

	int restartable = *(data + _header_len + 1);

	if (!_current_nr || cprio <= prio) {
		int tnr = _current_nr;
		int tprio = cprio;
		byte *tdata  = _current_data;

		chainSound(nr, data);
		nr   = tnr;
		prio = tprio;
		data = tdata;
		restartable = data ? *(data + _header_len + 1) : 0;
	}

	if (!_current_nr) {
		nr = 0;
		_next_nr = 0;
		_next_data = 0;
	}

	if (nr != _current_nr
		&& restartable
		&& (!_next_nr
		|| nprio <= prio)) {

		_next_nr = nr;
		_next_data = data;
	}
}

int Player_V2::getSoundStatus(int nr) const {
	return _current_nr == nr || _next_nr == nr;
}

int Player_V2::readBuffer(int16 *data, const int numSamples) {
	Common::StackLock lock(_mutex);

	uint step;
	uint len = numSamples / 2;

	do {
		if (!(_next_tick >> FIXP_SHIFT)) {
			_next_tick += _tick_len;
			nextTick();
		}

		step = len;
		if (step > (_next_tick >> FIXP_SHIFT))
			step = (_next_tick >> FIXP_SHIFT);
		if (_pcjr)
			generatePCjrSamples(data, step);
		else
			generateSpkSamples(data, step);
		data += 2 * step;
		_next_tick -= step << FIXP_SHIFT;
	} while (len -= step);

	return numSamples;
}

void Player_V2::lowPassFilter(int16 *sample, uint len) {
	for (uint i = 0; i < len; i++) {
		_level = (int) (_level * _decay
				+ sample[0] * (0x10000 - _decay)) >> 16;
		sample[0] = sample[1] = _level;
		sample += 2;
	}
}

void Player_V2::squareGenerator(int channel, int freq, int vol,
								int noiseFeedback, int16 *sample, uint len) {
	int32 period = _update_step * freq;
	int32 nsample;
	if (period == 0)
		period = _update_step;

	for (uint i = 0; i < len; i++) {
		uint32 duration = 0;

		if (_timer_output & (1 << channel))
			duration += _timer_count[channel];

		_timer_count[channel] -= (1 << FIXP_SHIFT);
		while (_timer_count[channel] <= 0) {

			if (noiseFeedback) {
				if (_RNG & 1) {
					_RNG ^= noiseFeedback;
					_timer_output ^= (1 << channel);
				}
				_RNG >>= 1;
			} else {
				_timer_output ^= (1 << channel);
			}

			if (_timer_output & (1 << channel))
				duration += period;

			_timer_count[channel] += period;
		}

		if (_timer_output & (1 << channel))
			duration -= _timer_count[channel];

		nsample = *sample +
			(((int32) (duration - (1 << (FIXP_SHIFT - 1)))
				* (int32) _volumetable[vol]) >> FIXP_SHIFT);
		/* overflow: clip value */
		if (nsample > 0x7fff)
			nsample = 0x7fff;
		if (nsample < -0x8000)
			nsample = -0x8000;
		*sample = nsample;
		// The following write isn't necessary, because the lowPassFilter does it for us
		//sample[1] = sample[0];
		sample += 2;
	}
}

void Player_V2::generateSpkSamples(int16 *data, uint len) {
	int winning_channel = -1;
	for (int i = 0; i < 4; i++) {
		if (winning_channel == -1
			&& _channels[i].d.volume
			&& _channels[i].d.time_left) {
			winning_channel = i;
		}
	}

	memset(data, 0, 2 * sizeof(int16) * len);
	if (winning_channel != -1) {
		squareGenerator(0, _channels[winning_channel].d.freq, 0,
				0, data, len);
	} else if (_level == 0)
		/* shortcut: no sound is being played. */
		return;

	lowPassFilter(data, len);
}

void Player_V2::generatePCjrSamples(int16 *data, uint len) {
	int i, j;
	int freq, vol;

	memset(data, 0, 2 * sizeof(int16) * len);
	bool hasdata = false;

	for (i = 1; i < 3; i++) {
		freq = _channels[i].d.freq >> 6;
		if (_channels[i].d.volume && _channels[i].d.time_left) {
			for (j = 0; j < i; j++) {
				if (_channels[j].d.volume
					&& _channels[j].d.time_left
					&& freq == (_channels[j].d.freq >> 6)) {
					/* HACK: this channel is playing at
					 * the same frequency as another.
					 * Synchronize it to the same phase to
					 * prevent interference.
					 */
					_timer_count[i] = _timer_count[j];
					_timer_output ^= (1 << i) &
						(_timer_output ^ _timer_output << (i - j));
				}
			}
		}
	}

	for (i = 0; i < 4; i++) {
		freq = _channels[i].d.freq >> 6;
		vol  = (65535 - _channels[i].d.volume) >> 12;
		if (!_channels[i].d.volume || !_channels[i].d.time_left) {
			_timer_count[i] -= len << FIXP_SHIFT;
			if (_timer_count[i] < 0)
				_timer_count[i] = 0;
		} else if (i < 3) {
			hasdata = true;
			squareGenerator(i, freq, vol, 0, data, len);
		} else {
			int noiseFB = (freq & 4) ? FB_WNOISE : FB_PNOISE;
			int n = (freq & 3);

			freq = (n == 3) ? 2 * (_channels[2].d.freq>>6) : 1 << (5 + n);
			hasdata = true;
			squareGenerator(i, freq, vol, noiseFB, data, len);
		}
#if 0
		debug(9, "channel[%d]: freq %d %.1f ; volume %d",
				i, freq, 111860.0 / freq,  vol);
#endif
	}

	if (_level || hasdata)
		lowPassFilter(data, len);
}

} // End of namespace Scumm