src/gb/audio.c (view raw)
1/* Copyright (c) 2013-2016 Jeffrey Pfau
2 *
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6#include <mgba/internal/gb/audio.h>
7
8#include <mgba/core/blip_buf.h>
9#include <mgba/core/interface.h>
10#include <mgba/core/sync.h>
11#include <mgba/internal/gb/gb.h>
12#include <mgba/internal/gb/serialize.h>
13#include <mgba/internal/gb/io.h>
14
15#ifdef _3DS
16#define blip_add_delta blip_add_delta_fast
17#endif
18
19#define FRAME_CYCLES (DMG_LR35902_FREQUENCY >> 9)
20
21const uint32_t DMG_LR35902_FREQUENCY = 0x400000;
22static const int CLOCKS_PER_BLIP_FRAME = 0x1000;
23static const unsigned BLIP_BUFFER_SIZE = 0x4000;
24const int GB_AUDIO_VOLUME_MAX = 0x100;
25
26static bool _writeSweep(struct GBAudioSweep* sweep, uint8_t value);
27static void _writeDuty(struct GBAudioEnvelope* envelope, uint8_t value);
28static bool _writeEnvelope(struct GBAudioEnvelope* envelope, uint8_t value, enum GBAudioStyle style);
29
30static void _resetSweep(struct GBAudioSweep* sweep);
31static bool _resetEnvelope(struct GBAudioEnvelope* sweep);
32
33static void _updateEnvelope(struct GBAudioEnvelope* envelope);
34static void _updateEnvelopeDead(struct GBAudioEnvelope* envelope);
35static bool _updateSweep(struct GBAudioSquareChannel* sweep, bool initial);
36
37static void _updateSquareSample(struct GBAudioSquareChannel* ch);
38static int32_t _updateSquareChannel(struct GBAudioSquareChannel* ch);
39
40static int8_t _coalesceNoiseChannel(struct GBAudioNoiseChannel* ch);
41
42static void _updateFrame(struct mTiming* timing, void* user, uint32_t cyclesLate);
43static void _updateChannel1(struct mTiming* timing, void* user, uint32_t cyclesLate);
44static void _updateChannel2(struct mTiming* timing, void* user, uint32_t cyclesLate);
45static void _updateChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate);
46static void _fadeChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate);
47static void _updateChannel4(struct mTiming* timing, void* user, uint32_t cyclesLate);
48static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate);
49
50void GBAudioInit(struct GBAudio* audio, size_t samples, uint8_t* nr52, enum GBAudioStyle style) {
51 audio->samples = samples;
52 audio->left = blip_new(BLIP_BUFFER_SIZE);
53 audio->right = blip_new(BLIP_BUFFER_SIZE);
54 audio->clockRate = DMG_LR35902_FREQUENCY;
55 // Guess too large; we hang producing extra samples if we guess too low
56 blip_set_rates(audio->left, DMG_LR35902_FREQUENCY, 96000);
57 blip_set_rates(audio->right, DMG_LR35902_FREQUENCY, 96000);
58 audio->forceDisableCh[0] = false;
59 audio->forceDisableCh[1] = false;
60 audio->forceDisableCh[2] = false;
61 audio->forceDisableCh[3] = false;
62 audio->masterVolume = GB_AUDIO_VOLUME_MAX;
63 audio->nr52 = nr52;
64 audio->style = style;
65 if (style == GB_AUDIO_GBA) {
66 audio->timingFactor = 4;
67 } else {
68 audio->timingFactor = 1;
69 }
70
71 audio->frameEvent.context = audio;
72 audio->frameEvent.name = "GB Audio Frame Sequencer";
73 audio->frameEvent.callback = _updateFrame;
74 audio->frameEvent.priority = 0x10;
75 audio->ch1Event.context = audio;
76 audio->ch1Event.name = "GB Audio Channel 1";
77 audio->ch1Event.callback = _updateChannel1;
78 audio->ch1Event.priority = 0x11;
79 audio->ch2Event.context = audio;
80 audio->ch2Event.name = "GB Audio Channel 2";
81 audio->ch2Event.callback = _updateChannel2;
82 audio->ch2Event.priority = 0x12;
83 audio->ch3Event.context = audio;
84 audio->ch3Event.name = "GB Audio Channel 3";
85 audio->ch3Event.callback = _updateChannel3;
86 audio->ch3Event.priority = 0x13;
87 audio->ch3Fade.context = audio;
88 audio->ch3Fade.name = "GB Audio Channel 3 Memory";
89 audio->ch3Fade.callback = _fadeChannel3;
90 audio->ch3Fade.priority = 0x14;
91 audio->ch4Event.context = audio;
92 audio->ch4Event.name = "GB Audio Channel 4";
93 audio->ch4Event.callback = _updateChannel4;
94 audio->ch4Event.priority = 0x15;
95 audio->sampleEvent.context = audio;
96 audio->sampleEvent.name = "GB Audio Sample";
97 audio->sampleEvent.callback = _sample;
98 audio->ch1Event.priority = 0x18;
99}
100
101void GBAudioDeinit(struct GBAudio* audio) {
102 blip_delete(audio->left);
103 blip_delete(audio->right);
104}
105
106void GBAudioReset(struct GBAudio* audio) {
107 mTimingDeschedule(audio->timing, &audio->frameEvent);
108 mTimingDeschedule(audio->timing, &audio->ch1Event);
109 mTimingDeschedule(audio->timing, &audio->ch2Event);
110 mTimingDeschedule(audio->timing, &audio->ch3Event);
111 mTimingDeschedule(audio->timing, &audio->ch3Fade);
112 mTimingDeschedule(audio->timing, &audio->ch4Event);
113 mTimingDeschedule(audio->timing, &audio->sampleEvent);
114 if (audio->style != GB_AUDIO_GBA) {
115 mTimingSchedule(audio->timing, &audio->sampleEvent, 0);
116 }
117 if (audio->style == GB_AUDIO_GBA) {
118 mTimingSchedule(audio->timing, &audio->frameEvent, 0);
119 }
120 audio->ch1 = (struct GBAudioSquareChannel) { .envelope = { .dead = 2 } };
121 audio->ch2 = (struct GBAudioSquareChannel) { .envelope = { .dead = 2 } };
122 audio->ch3 = (struct GBAudioWaveChannel) { .bank = 0 };
123 audio->ch4 = (struct GBAudioNoiseChannel) { .nSamples = 0 };
124 // TODO: DMG randomness
125 audio->ch3.wavedata8[0] = 0x00;
126 audio->ch3.wavedata8[1] = 0xFF;
127 audio->ch3.wavedata8[2] = 0x00;
128 audio->ch3.wavedata8[3] = 0xFF;
129 audio->ch3.wavedata8[4] = 0x00;
130 audio->ch3.wavedata8[5] = 0xFF;
131 audio->ch3.wavedata8[6] = 0x00;
132 audio->ch3.wavedata8[7] = 0xFF;
133 audio->ch3.wavedata8[8] = 0x00;
134 audio->ch3.wavedata8[9] = 0xFF;
135 audio->ch3.wavedata8[10] = 0x00;
136 audio->ch3.wavedata8[11] = 0xFF;
137 audio->ch3.wavedata8[12] = 0x00;
138 audio->ch3.wavedata8[13] = 0xFF;
139 audio->ch3.wavedata8[14] = 0x00;
140 audio->ch3.wavedata8[15] = 0xFF;
141 audio->ch4 = (struct GBAudioNoiseChannel) { .envelope = { .dead = 2 } };
142 audio->frame = 0;
143 audio->sampleInterval = 128;
144 audio->lastLeft = 0;
145 audio->lastRight = 0;
146 audio->capLeft = 0;
147 audio->capRight = 0;
148 audio->clock = 0;
149 audio->playingCh1 = false;
150 audio->playingCh2 = false;
151 audio->playingCh3 = false;
152 audio->playingCh4 = false;
153 if (audio->p && audio->p->model != GB_MODEL_SGB) {
154 audio->playingCh1 = true;
155 audio->enable = true;
156 *audio->nr52 |= 0x01;
157 }
158}
159
160void GBAudioResizeBuffer(struct GBAudio* audio, size_t samples) {
161 mCoreSyncLockAudio(audio->p->sync);
162 audio->samples = samples;
163 blip_clear(audio->left);
164 blip_clear(audio->right);
165 audio->clock = 0;
166 mCoreSyncConsumeAudio(audio->p->sync);
167}
168
169void GBAudioWriteNR10(struct GBAudio* audio, uint8_t value) {
170 if (!_writeSweep(&audio->ch1.sweep, value)) {
171 mTimingDeschedule(audio->timing, &audio->ch1Event);
172 audio->playingCh1 = false;
173 *audio->nr52 &= ~0x0001;
174 }
175}
176
177void GBAudioWriteNR11(struct GBAudio* audio, uint8_t value) {
178 _writeDuty(&audio->ch1.envelope, value);
179 audio->ch1.control.length = 64 - audio->ch1.envelope.length;
180}
181
182void GBAudioWriteNR12(struct GBAudio* audio, uint8_t value) {
183 if (!_writeEnvelope(&audio->ch1.envelope, value, audio->style)) {
184 mTimingDeschedule(audio->timing, &audio->ch1Event);
185 audio->playingCh1 = false;
186 *audio->nr52 &= ~0x0001;
187 }
188}
189
190void GBAudioWriteNR13(struct GBAudio* audio, uint8_t value) {
191 audio->ch1.control.frequency &= 0x700;
192 audio->ch1.control.frequency |= GBAudioRegisterControlGetFrequency(value);
193}
194
195void GBAudioWriteNR14(struct GBAudio* audio, uint8_t value) {
196 audio->ch1.control.frequency &= 0xFF;
197 audio->ch1.control.frequency |= GBAudioRegisterControlGetFrequency(value << 8);
198 bool wasStop = audio->ch1.control.stop;
199 audio->ch1.control.stop = GBAudioRegisterControlGetStop(value << 8);
200 if (!wasStop && audio->ch1.control.stop && audio->ch1.control.length && !(audio->frame & 1)) {
201 --audio->ch1.control.length;
202 if (audio->ch1.control.length == 0) {
203 mTimingDeschedule(audio->timing, &audio->ch1Event);
204 audio->playingCh1 = false;
205 }
206 }
207 if (GBAudioRegisterControlIsRestart(value << 8)) {
208 audio->playingCh1 = _resetEnvelope(&audio->ch1.envelope);
209 audio->ch1.sweep.realFrequency = audio->ch1.control.frequency;
210 _resetSweep(&audio->ch1.sweep);
211 if (audio->playingCh1 && audio->ch1.sweep.shift) {
212 audio->playingCh1 = _updateSweep(&audio->ch1, true);
213 }
214 if (!audio->ch1.control.length) {
215 audio->ch1.control.length = 64;
216 if (audio->ch1.control.stop && !(audio->frame & 1)) {
217 --audio->ch1.control.length;
218 }
219 }
220 if (audio->playingCh1 && audio->ch1.envelope.dead != 2) {
221 mTimingDeschedule(audio->timing, &audio->ch1Event);
222 mTimingSchedule(audio->timing, &audio->ch1Event, 0);
223 }
224 }
225 *audio->nr52 &= ~0x0001;
226 *audio->nr52 |= audio->playingCh1;
227}
228
229void GBAudioWriteNR21(struct GBAudio* audio, uint8_t value) {
230 _writeDuty(&audio->ch2.envelope, value);
231 audio->ch2.control.length = 64 - audio->ch2.envelope.length;
232}
233
234void GBAudioWriteNR22(struct GBAudio* audio, uint8_t value) {
235 if (!_writeEnvelope(&audio->ch2.envelope, value, audio->style)) {
236 mTimingDeschedule(audio->timing, &audio->ch2Event);
237 audio->playingCh2 = false;
238 *audio->nr52 &= ~0x0002;
239 }
240}
241
242void GBAudioWriteNR23(struct GBAudio* audio, uint8_t value) {
243 audio->ch2.control.frequency &= 0x700;
244 audio->ch2.control.frequency |= GBAudioRegisterControlGetFrequency(value);
245}
246
247void GBAudioWriteNR24(struct GBAudio* audio, uint8_t value) {
248 audio->ch2.control.frequency &= 0xFF;
249 audio->ch2.control.frequency |= GBAudioRegisterControlGetFrequency(value << 8);
250 bool wasStop = audio->ch2.control.stop;
251 audio->ch2.control.stop = GBAudioRegisterControlGetStop(value << 8);
252 if (!wasStop && audio->ch2.control.stop && audio->ch2.control.length && !(audio->frame & 1)) {
253 --audio->ch2.control.length;
254 if (audio->ch2.control.length == 0) {
255 mTimingDeschedule(audio->timing, &audio->ch2Event);
256 audio->playingCh2 = false;
257 }
258 }
259 if (GBAudioRegisterControlIsRestart(value << 8)) {
260 audio->playingCh2 = _resetEnvelope(&audio->ch2.envelope);
261
262 if (!audio->ch2.control.length) {
263 audio->ch2.control.length = 64;
264 if (audio->ch2.control.stop && !(audio->frame & 1)) {
265 --audio->ch2.control.length;
266 }
267 }
268 if (audio->playingCh2 && audio->ch2.envelope.dead != 2) {
269 mTimingDeschedule(audio->timing, &audio->ch2Event);
270 mTimingSchedule(audio->timing, &audio->ch2Event, 0);
271 }
272 }
273 *audio->nr52 &= ~0x0002;
274 *audio->nr52 |= audio->playingCh2 << 1;
275}
276
277void GBAudioWriteNR30(struct GBAudio* audio, uint8_t value) {
278 audio->ch3.enable = GBAudioRegisterBankGetEnable(value);
279 if (!audio->ch3.enable) {
280 audio->playingCh3 = false;
281 *audio->nr52 &= ~0x0004;
282 }
283}
284
285void GBAudioWriteNR31(struct GBAudio* audio, uint8_t value) {
286 audio->ch3.length = 256 - value;
287}
288
289void GBAudioWriteNR32(struct GBAudio* audio, uint8_t value) {
290 audio->ch3.volume = GBAudioRegisterBankVolumeGetVolumeGB(value);
291}
292
293void GBAudioWriteNR33(struct GBAudio* audio, uint8_t value) {
294 audio->ch3.rate &= 0x700;
295 audio->ch3.rate |= GBAudioRegisterControlGetRate(value);
296}
297
298void GBAudioWriteNR34(struct GBAudio* audio, uint8_t value) {
299 audio->ch3.rate &= 0xFF;
300 audio->ch3.rate |= GBAudioRegisterControlGetRate(value << 8);
301 bool wasStop = audio->ch3.stop;
302 audio->ch3.stop = GBAudioRegisterControlGetStop(value << 8);
303 if (!wasStop && audio->ch3.stop && audio->ch3.length && !(audio->frame & 1)) {
304 --audio->ch3.length;
305 if (audio->ch3.length == 0) {
306 audio->playingCh3 = false;
307 }
308 }
309 bool wasEnable = audio->playingCh3;
310 if (GBAudioRegisterControlIsRestart(value << 8)) {
311 audio->playingCh3 = audio->ch3.enable;
312 if (!audio->ch3.length) {
313 audio->ch3.length = 256;
314 if (audio->ch3.stop && !(audio->frame & 1)) {
315 --audio->ch3.length;
316 }
317 }
318
319 if (audio->style == GB_AUDIO_DMG && wasEnable && audio->playingCh3 && audio->ch3.readable) {
320 if (audio->ch3.window < 8) {
321 audio->ch3.wavedata8[0] = audio->ch3.wavedata8[audio->ch3.window >> 1];
322 } else {
323 audio->ch3.wavedata8[0] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3)];
324 audio->ch3.wavedata8[1] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 1];
325 audio->ch3.wavedata8[2] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 2];
326 audio->ch3.wavedata8[3] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 3];
327 }
328 }
329 audio->ch3.window = 0;
330 audio->ch3.sample = 0;
331 }
332 mTimingDeschedule(audio->timing, &audio->ch3Fade);
333 mTimingDeschedule(audio->timing, &audio->ch3Event);
334 if (audio->playingCh3) {
335 audio->ch3.readable = audio->style != GB_AUDIO_DMG;
336 // TODO: Where does this cycle delay come from?
337 mTimingSchedule(audio->timing, &audio->ch3Event, audio->timingFactor * 4 + 2 * (2048 - audio->ch3.rate));
338 }
339 *audio->nr52 &= ~0x0004;
340 *audio->nr52 |= audio->playingCh3 << 2;
341}
342
343void GBAudioWriteNR41(struct GBAudio* audio, uint8_t value) {
344 _writeDuty(&audio->ch4.envelope, value);
345 audio->ch4.length = 64 - audio->ch4.envelope.length;
346}
347
348void GBAudioWriteNR42(struct GBAudio* audio, uint8_t value) {
349 if (!_writeEnvelope(&audio->ch4.envelope, value, audio->style)) {
350 mTimingDeschedule(audio->timing, &audio->ch4Event);
351 audio->playingCh4 = false;
352 *audio->nr52 &= ~0x0008;
353 }
354}
355
356void GBAudioWriteNR43(struct GBAudio* audio, uint8_t value) {
357 audio->ch4.ratio = GBAudioRegisterNoiseFeedbackGetRatio(value);
358 audio->ch4.frequency = GBAudioRegisterNoiseFeedbackGetFrequency(value);
359 audio->ch4.power = GBAudioRegisterNoiseFeedbackGetPower(value);
360}
361
362void GBAudioWriteNR44(struct GBAudio* audio, uint8_t value) {
363 bool wasStop = audio->ch4.stop;
364 audio->ch4.stop = GBAudioRegisterNoiseControlGetStop(value);
365 if (!wasStop && audio->ch4.stop && audio->ch4.length && !(audio->frame & 1)) {
366 --audio->ch4.length;
367 if (audio->ch4.length == 0) {
368 mTimingDeschedule(audio->timing, &audio->ch4Event);
369 audio->playingCh4 = false;
370 }
371 }
372 if (GBAudioRegisterNoiseControlIsRestart(value)) {
373 audio->playingCh4 = _resetEnvelope(&audio->ch4.envelope);
374
375 if (audio->ch4.power) {
376 audio->ch4.lfsr = 0x7F;
377 } else {
378 audio->ch4.lfsr = 0x7FFF;
379 }
380 if (!audio->ch4.length) {
381 audio->ch4.length = 64;
382 if (audio->ch4.stop && !(audio->frame & 1)) {
383 --audio->ch4.length;
384 }
385 }
386 if (audio->playingCh4 && audio->ch4.envelope.dead != 2) {
387 mTimingDeschedule(audio->timing, &audio->ch4Event);
388 mTimingSchedule(audio->timing, &audio->ch4Event, 0);
389 }
390 }
391 *audio->nr52 &= ~0x0008;
392 *audio->nr52 |= audio->playingCh4 << 3;
393}
394
395void GBAudioWriteNR50(struct GBAudio* audio, uint8_t value) {
396 audio->volumeRight = GBRegisterNR50GetVolumeRight(value);
397 audio->volumeLeft = GBRegisterNR50GetVolumeLeft(value);
398}
399
400void GBAudioWriteNR51(struct GBAudio* audio, uint8_t value) {
401 audio->ch1Right = GBRegisterNR51GetCh1Right(value);
402 audio->ch2Right = GBRegisterNR51GetCh2Right(value);
403 audio->ch3Right = GBRegisterNR51GetCh3Right(value);
404 audio->ch4Right = GBRegisterNR51GetCh4Right(value);
405 audio->ch1Left = GBRegisterNR51GetCh1Left(value);
406 audio->ch2Left = GBRegisterNR51GetCh2Left(value);
407 audio->ch3Left = GBRegisterNR51GetCh3Left(value);
408 audio->ch4Left = GBRegisterNR51GetCh4Left(value);
409}
410
411void GBAudioWriteNR52(struct GBAudio* audio, uint8_t value) {
412 bool wasEnable = audio->enable;
413 audio->enable = GBAudioEnableGetEnable(value);
414 if (!audio->enable) {
415 audio->playingCh1 = 0;
416 audio->playingCh2 = 0;
417 audio->playingCh3 = 0;
418 audio->playingCh4 = 0;
419 GBAudioWriteNR10(audio, 0);
420 GBAudioWriteNR12(audio, 0);
421 GBAudioWriteNR13(audio, 0);
422 GBAudioWriteNR14(audio, 0);
423 GBAudioWriteNR22(audio, 0);
424 GBAudioWriteNR23(audio, 0);
425 GBAudioWriteNR24(audio, 0);
426 GBAudioWriteNR30(audio, 0);
427 GBAudioWriteNR32(audio, 0);
428 GBAudioWriteNR33(audio, 0);
429 GBAudioWriteNR34(audio, 0);
430 GBAudioWriteNR42(audio, 0);
431 GBAudioWriteNR43(audio, 0);
432 GBAudioWriteNR44(audio, 0);
433 GBAudioWriteNR50(audio, 0);
434 GBAudioWriteNR51(audio, 0);
435 if (audio->style != GB_AUDIO_DMG) {
436 GBAudioWriteNR11(audio, 0);
437 GBAudioWriteNR21(audio, 0);
438 GBAudioWriteNR31(audio, 0);
439 GBAudioWriteNR41(audio, 0);
440 }
441
442 if (audio->p) {
443 audio->p->memory.io[REG_NR10] = 0;
444 audio->p->memory.io[REG_NR11] = 0;
445 audio->p->memory.io[REG_NR12] = 0;
446 audio->p->memory.io[REG_NR13] = 0;
447 audio->p->memory.io[REG_NR14] = 0;
448 audio->p->memory.io[REG_NR21] = 0;
449 audio->p->memory.io[REG_NR22] = 0;
450 audio->p->memory.io[REG_NR23] = 0;
451 audio->p->memory.io[REG_NR24] = 0;
452 audio->p->memory.io[REG_NR30] = 0;
453 audio->p->memory.io[REG_NR31] = 0;
454 audio->p->memory.io[REG_NR32] = 0;
455 audio->p->memory.io[REG_NR33] = 0;
456 audio->p->memory.io[REG_NR34] = 0;
457 audio->p->memory.io[REG_NR42] = 0;
458 audio->p->memory.io[REG_NR43] = 0;
459 audio->p->memory.io[REG_NR44] = 0;
460 audio->p->memory.io[REG_NR50] = 0;
461 audio->p->memory.io[REG_NR51] = 0;
462 if (audio->style != GB_AUDIO_DMG) {
463 audio->p->memory.io[REG_NR11] = 0;
464 audio->p->memory.io[REG_NR21] = 0;
465 audio->p->memory.io[REG_NR31] = 0;
466 audio->p->memory.io[REG_NR41] = 0;
467 }
468 }
469 *audio->nr52 &= ~0x000F;
470 } else if (!wasEnable) {
471 audio->frame = 7;
472 }
473}
474
475void _updateFrame(struct mTiming* timing, void* user, uint32_t cyclesLate) {
476 struct GBAudio* audio = user;
477 GBAudioUpdateFrame(audio, timing);
478 if (audio->style == GB_AUDIO_GBA) {
479 mTimingSchedule(timing, &audio->frameEvent, audio->timingFactor * FRAME_CYCLES - cyclesLate);
480 }
481}
482
483void GBAudioUpdateFrame(struct GBAudio* audio, struct mTiming* timing) {
484 int frame = (audio->frame + 1) & 7;
485 audio->frame = frame;
486
487 switch (frame) {
488 case 2:
489 case 6:
490 if (audio->ch1.sweep.enable) {
491 --audio->ch1.sweep.step;
492 if (audio->ch1.sweep.step == 0) {
493 audio->playingCh1 = _updateSweep(&audio->ch1, false);
494 *audio->nr52 &= ~0x0001;
495 *audio->nr52 |= audio->playingCh1;
496 }
497 }
498 // Fall through
499 case 0:
500 case 4:
501 if (audio->ch1.control.length && audio->ch1.control.stop) {
502 --audio->ch1.control.length;
503 if (audio->ch1.control.length == 0) {
504 mTimingDeschedule(timing, &audio->ch1Event);
505 audio->playingCh1 = 0;
506 *audio->nr52 &= ~0x0001;
507 }
508 }
509
510 if (audio->ch2.control.length && audio->ch2.control.stop) {
511 --audio->ch2.control.length;
512 if (audio->ch2.control.length == 0) {
513 mTimingDeschedule(timing, &audio->ch2Event);
514 audio->playingCh2 = 0;
515 *audio->nr52 &= ~0x0002;
516 }
517 }
518
519 if (audio->ch3.length && audio->ch3.stop) {
520 --audio->ch3.length;
521 if (audio->ch3.length == 0) {
522 mTimingDeschedule(timing, &audio->ch3Event);
523 audio->playingCh3 = 0;
524 *audio->nr52 &= ~0x0004;
525 }
526 }
527
528 if (audio->ch4.length && audio->ch4.stop) {
529 --audio->ch4.length;
530 if (audio->ch4.length == 0) {
531 mTimingDeschedule(timing, &audio->ch4Event);
532 audio->playingCh4 = 0;
533 *audio->nr52 &= ~0x0008;
534 }
535 }
536 break;
537 case 7:
538 if (audio->playingCh1 && !audio->ch1.envelope.dead) {
539 --audio->ch1.envelope.nextStep;
540 if (audio->ch1.envelope.nextStep == 0) {
541 _updateEnvelope(&audio->ch1.envelope);
542 if (audio->ch1.envelope.dead == 2) {
543 mTimingDeschedule(timing, &audio->ch1Event);
544 }
545 _updateSquareSample(&audio->ch1);
546 }
547 }
548
549 if (audio->playingCh2 && !audio->ch2.envelope.dead) {
550 --audio->ch2.envelope.nextStep;
551 if (audio->ch2.envelope.nextStep == 0) {
552 _updateEnvelope(&audio->ch2.envelope);
553 if (audio->ch2.envelope.dead == 2) {
554 mTimingDeschedule(timing, &audio->ch2Event);
555 }
556 _updateSquareSample(&audio->ch2);
557 }
558 }
559
560 if (audio->playingCh4 && !audio->ch4.envelope.dead) {
561 --audio->ch4.envelope.nextStep;
562 if (audio->ch4.envelope.nextStep == 0) {
563 int8_t sample = audio->ch4.sample > 0;
564 audio->ch4.samples -= audio->ch4.sample;
565 _updateEnvelope(&audio->ch4.envelope);
566 if (audio->ch4.envelope.dead == 2) {
567 mTimingDeschedule(timing, &audio->ch4Event);
568 }
569 audio->ch4.sample = sample * audio->ch4.envelope.currentVolume;
570 audio->ch4.samples += audio->ch4.sample;
571 }
572 }
573 break;
574 }
575}
576
577void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right) {
578 int dcOffset = audio->style == GB_AUDIO_GBA ? 0 : -0x8;
579 int sampleLeft = dcOffset;
580 int sampleRight = dcOffset;
581
582 if (audio->playingCh1 && !audio->forceDisableCh[0]) {
583 if (audio->ch1Left) {
584 sampleLeft += audio->ch1.sample;
585 }
586
587 if (audio->ch1Right) {
588 sampleRight += audio->ch1.sample;
589 }
590 }
591
592 if (audio->playingCh2 && !audio->forceDisableCh[1]) {
593 if (audio->ch2Left) {
594 sampleLeft += audio->ch2.sample;
595 }
596
597 if (audio->ch2Right) {
598 sampleRight += audio->ch2.sample;
599 }
600 }
601
602 if (audio->playingCh3 && !audio->forceDisableCh[2]) {
603 if (audio->ch3Left) {
604 sampleLeft += audio->ch3.sample;
605 }
606
607 if (audio->ch3Right) {
608 sampleRight += audio->ch3.sample;
609 }
610 }
611
612 if (audio->playingCh4 && !audio->forceDisableCh[3]) {
613 int8_t sample = _coalesceNoiseChannel(&audio->ch4);
614 if (audio->ch4Left) {
615 sampleLeft += sample;
616 }
617
618 if (audio->ch4Right) {
619 sampleRight += sample;
620 }
621 }
622
623 sampleLeft <<= 3;
624 sampleRight <<= 3;
625
626 *left = sampleLeft * (1 + audio->volumeLeft);
627 *right = sampleRight * (1 + audio->volumeRight);
628}
629
630static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate) {
631 struct GBAudio* audio = user;
632 int16_t sampleLeft = 0;
633 int16_t sampleRight = 0;
634 GBAudioSamplePSG(audio, &sampleLeft, &sampleRight);
635 sampleLeft = (sampleLeft * audio->masterVolume * 6) >> 7;
636 sampleRight = (sampleRight * audio->masterVolume * 6) >> 7;
637
638 mCoreSyncLockAudio(audio->p->sync);
639 unsigned produced;
640
641 int16_t degradedLeft = sampleLeft - (audio->capLeft >> 16);
642 int16_t degradedRight = sampleRight - (audio->capRight >> 16);
643 audio->capLeft = (sampleLeft << 16) - degradedLeft * 65184;
644 audio->capRight = (sampleRight << 16) - degradedRight * 65184;
645 sampleLeft = degradedLeft;
646 sampleRight = degradedRight;
647
648 if ((size_t) blip_samples_avail(audio->left) < audio->samples) {
649 blip_add_delta(audio->left, audio->clock, sampleLeft - audio->lastLeft);
650 blip_add_delta(audio->right, audio->clock, sampleRight - audio->lastRight);
651 audio->lastLeft = sampleLeft;
652 audio->lastRight = sampleRight;
653 audio->clock += audio->sampleInterval;
654 if (audio->clock >= CLOCKS_PER_BLIP_FRAME) {
655 blip_end_frame(audio->left, CLOCKS_PER_BLIP_FRAME);
656 blip_end_frame(audio->right, CLOCKS_PER_BLIP_FRAME);
657 audio->clock -= CLOCKS_PER_BLIP_FRAME;
658 }
659 }
660 produced = blip_samples_avail(audio->left);
661 if (audio->p->stream && audio->p->stream->postAudioFrame) {
662 audio->p->stream->postAudioFrame(audio->p->stream, sampleLeft, sampleRight);
663 }
664 bool wait = produced >= audio->samples;
665 if (!mCoreSyncProduceAudio(audio->p->sync, audio->left, audio->samples)) {
666 // Interrupted
667 audio->p->earlyExit = true;
668 }
669
670 if (wait && audio->p->stream && audio->p->stream->postAudioBuffer) {
671 audio->p->stream->postAudioBuffer(audio->p->stream, audio->left, audio->right);
672 }
673 mTimingSchedule(timing, &audio->sampleEvent, audio->sampleInterval * audio->timingFactor - cyclesLate);
674}
675
676bool _resetEnvelope(struct GBAudioEnvelope* envelope) {
677 envelope->currentVolume = envelope->initialVolume;
678 _updateEnvelopeDead(envelope);
679 if (!envelope->dead) {
680 envelope->nextStep = envelope->stepTime;
681 }
682 return envelope->initialVolume || envelope->direction;
683}
684
685void _resetSweep(struct GBAudioSweep* sweep) {
686 sweep->step = sweep->time;
687 sweep->enable = (sweep->step != 8) || sweep->shift;
688 sweep->occurred = false;
689}
690
691bool _writeSweep(struct GBAudioSweep* sweep, uint8_t value) {
692 sweep->shift = GBAudioRegisterSquareSweepGetShift(value);
693 bool oldDirection = sweep->direction;
694 sweep->direction = GBAudioRegisterSquareSweepGetDirection(value);
695 bool on = true;
696 if (sweep->occurred && oldDirection && !sweep->direction) {
697 on = false;
698 }
699 sweep->occurred = false;
700 sweep->time = GBAudioRegisterSquareSweepGetTime(value);
701 if (!sweep->time) {
702 sweep->time = 8;
703 }
704 return on;
705}
706
707void _writeDuty(struct GBAudioEnvelope* envelope, uint8_t value) {
708 envelope->length = GBAudioRegisterDutyGetLength(value);
709 envelope->duty = GBAudioRegisterDutyGetDuty(value);
710}
711
712bool _writeEnvelope(struct GBAudioEnvelope* envelope, uint8_t value, enum GBAudioStyle style) {
713 envelope->stepTime = GBAudioRegisterSweepGetStepTime(value);
714 envelope->direction = GBAudioRegisterSweepGetDirection(value);
715 envelope->initialVolume = GBAudioRegisterSweepGetInitialVolume(value);
716 if (style == GB_AUDIO_DMG && !envelope->stepTime) {
717 // TODO: Improve "zombie" mode
718 ++envelope->currentVolume;
719 envelope->currentVolume &= 0xF;
720 }
721 _updateEnvelopeDead(envelope);
722 return (envelope->initialVolume || envelope->direction) && envelope->dead != 2;
723}
724
725static void _updateSquareSample(struct GBAudioSquareChannel* ch) {
726 ch->sample = ch->control.hi * ch->envelope.currentVolume;
727}
728
729static int32_t _updateSquareChannel(struct GBAudioSquareChannel* ch) {
730 ch->control.hi = !ch->control.hi;
731 _updateSquareSample(ch);
732 int period = 4 * (2048 - ch->control.frequency);
733 switch (ch->envelope.duty) {
734 case 0:
735 return ch->control.hi ? period : period * 7;
736 case 1:
737 return ch->control.hi ? period * 2 : period * 6;
738 case 2:
739 return period * 4;
740 case 3:
741 return ch->control.hi ? period * 6 : period * 2;
742 default:
743 // This should never be hit
744 return period * 4;
745 }
746}
747
748static int8_t _coalesceNoiseChannel(struct GBAudioNoiseChannel* ch) {
749 if (!ch->nSamples) {
750 return ch->sample;
751 }
752 // TODO keep track of timing
753 int8_t sample = ch->samples / ch->nSamples;
754 ch->nSamples = 0;
755 ch->samples = 0;
756 return sample;
757}
758
759static void _updateEnvelope(struct GBAudioEnvelope* envelope) {
760 if (envelope->direction) {
761 ++envelope->currentVolume;
762 } else {
763 --envelope->currentVolume;
764 }
765 if (envelope->currentVolume >= 15) {
766 envelope->currentVolume = 15;
767 envelope->dead = 1;
768 } else if (envelope->currentVolume <= 0) {
769 envelope->currentVolume = 0;
770 envelope->dead = 2;
771 } else {
772 envelope->nextStep = envelope->stepTime;
773 }
774}
775
776static void _updateEnvelopeDead(struct GBAudioEnvelope* envelope) {
777 if (!envelope->stepTime) {
778 envelope->dead = envelope->currentVolume ? 1 : 2;
779 } else if (!envelope->direction && !envelope->currentVolume) {
780 envelope->dead = 2;
781 } else if (envelope->direction && envelope->currentVolume == 0xF) {
782 envelope->dead = 1;
783 } else {
784 envelope->dead = 0;
785 }
786}
787
788static bool _updateSweep(struct GBAudioSquareChannel* ch, bool initial) {
789 if (initial || ch->sweep.time != 8) {
790 int frequency = ch->sweep.realFrequency;
791 if (ch->sweep.direction) {
792 frequency -= frequency >> ch->sweep.shift;
793 if (!initial && frequency >= 0) {
794 ch->control.frequency = frequency;
795 ch->sweep.realFrequency = frequency;
796 }
797 } else {
798 frequency += frequency >> ch->sweep.shift;
799 if (frequency < 2048) {
800 if (!initial && ch->sweep.shift) {
801 ch->control.frequency = frequency;
802 ch->sweep.realFrequency = frequency;
803 if (!_updateSweep(ch, true)) {
804 return false;
805 }
806 }
807 } else {
808 return false;
809 }
810 }
811 ch->sweep.occurred = true;
812 }
813 ch->sweep.step = ch->sweep.time;
814 return true;
815}
816
817static void _updateChannel1(struct mTiming* timing, void* user, uint32_t cyclesLate) {
818 struct GBAudio* audio = user;
819 struct GBAudioSquareChannel* ch = &audio->ch1;
820 int cycles = _updateSquareChannel(ch);
821 mTimingSchedule(timing, &audio->ch1Event, audio->timingFactor * cycles - cyclesLate);
822}
823
824static void _updateChannel2(struct mTiming* timing, void* user, uint32_t cyclesLate) {
825 struct GBAudio* audio = user;
826 struct GBAudioSquareChannel* ch = &audio->ch2;
827 int cycles = _updateSquareChannel(ch);
828 mTimingSchedule(timing, &audio->ch2Event, audio->timingFactor * cycles - cyclesLate);
829}
830
831static void _updateChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
832 struct GBAudio* audio = user;
833 struct GBAudioWaveChannel* ch = &audio->ch3;
834 int i;
835 int volume;
836 switch (ch->volume) {
837 case 0:
838 volume = 4;
839 break;
840 case 1:
841 volume = 0;
842 break;
843 case 2:
844 volume = 1;
845 break;
846 default:
847 case 3:
848 volume = 2;
849 break;
850 }
851 int start;
852 int end;
853 switch (audio->style) {
854 case GB_AUDIO_DMG:
855 default:
856 ++ch->window;
857 ch->window &= 0x1F;
858 ch->sample = ch->wavedata8[ch->window >> 1];
859 if (!(ch->window & 1)) {
860 ch->sample >>= 4;
861 }
862 ch->sample &= 0xF;
863 break;
864 case GB_AUDIO_GBA:
865 if (ch->size) {
866 start = 7;
867 end = 0;
868 } else if (ch->bank) {
869 start = 7;
870 end = 4;
871 } else {
872 start = 3;
873 end = 0;
874 }
875 uint32_t bitsCarry = ch->wavedata32[end] & 0x000000F0;
876 uint32_t bits;
877 for (i = start; i >= end; --i) {
878 bits = ch->wavedata32[i] & 0x000000F0;
879 ch->wavedata32[i] = ((ch->wavedata32[i] & 0x0F0F0F0F) << 4) | ((ch->wavedata32[i] & 0xF0F0F000) >> 12);
880 ch->wavedata32[i] |= bitsCarry << 20;
881 bitsCarry = bits;
882 }
883 ch->sample = bitsCarry >> 4;
884 break;
885 }
886 if (ch->volume > 3) {
887 ch->sample += ch->sample << 1;
888 }
889 ch->sample >>= volume;
890 audio->ch3.readable = true;
891 if (audio->style == GB_AUDIO_DMG) {
892 mTimingDeschedule(audio->timing, &audio->ch3Fade);
893 mTimingSchedule(timing, &audio->ch3Fade, 2 - cyclesLate);
894 }
895 int cycles = 2 * (2048 - ch->rate);
896 mTimingSchedule(timing, &audio->ch3Event, audio->timingFactor * cycles - cyclesLate);
897}
898static void _fadeChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
899 UNUSED(timing);
900 UNUSED(cyclesLate);
901 struct GBAudio* audio = user;
902 audio->ch3.readable = false;
903}
904
905static void _updateChannel4(struct mTiming* timing, void* user, uint32_t cyclesLate) {
906 struct GBAudio* audio = user;
907 struct GBAudioNoiseChannel* ch = &audio->ch4;
908
909 int32_t cycles = ch->ratio ? 2 * ch->ratio : 1;
910 cycles <<= ch->frequency;
911 cycles *= 8 * audio->timingFactor;
912
913 int lsb = ch->lfsr & 1;
914 ch->sample = lsb * ch->envelope.currentVolume;
915 ++ch->nSamples;
916 ch->samples += ch->sample;
917 ch->lfsr >>= 1;
918 ch->lfsr ^= (lsb * 0x60) << (ch->power ? 0 : 8);
919
920 mTimingSchedule(timing, &audio->ch4Event, cycles - cyclesLate);
921}
922
923void GBAudioPSGSerialize(const struct GBAudio* audio, struct GBSerializedPSGState* state, uint32_t* flagsOut) {
924 uint32_t flags = 0;
925 uint32_t ch1Flags = 0;
926 uint32_t ch2Flags = 0;
927 uint32_t ch4Flags = 0;
928
929 flags = GBSerializedAudioFlagsSetFrame(flags, audio->frame);
930 STORE_32LE(audio->frameEvent.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextFrame);
931
932 flags = GBSerializedAudioFlagsSetCh1Volume(flags, audio->ch1.envelope.currentVolume);
933 flags = GBSerializedAudioFlagsSetCh1Dead(flags, audio->ch1.envelope.dead);
934 flags = GBSerializedAudioFlagsSetCh1Hi(flags, audio->ch1.control.hi);
935 flags = GBSerializedAudioFlagsSetCh1SweepEnabled(flags, audio->ch1.sweep.enable);
936 flags = GBSerializedAudioFlagsSetCh1SweepOccurred(flags, audio->ch1.sweep.occurred);
937 ch1Flags = GBSerializedAudioEnvelopeSetLength(ch1Flags, audio->ch1.control.length);
938 ch1Flags = GBSerializedAudioEnvelopeSetNextStep(ch1Flags, audio->ch1.envelope.nextStep);
939 ch1Flags = GBSerializedAudioEnvelopeSetFrequency(ch1Flags, audio->ch1.sweep.realFrequency);
940 STORE_32LE(ch1Flags, 0, &state->ch1.envelope);
941 STORE_32LE(audio->ch1Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextEvent);
942
943 flags = GBSerializedAudioFlagsSetCh2Volume(flags, audio->ch2.envelope.currentVolume);
944 flags = GBSerializedAudioFlagsSetCh2Dead(flags, audio->ch2.envelope.dead);
945 flags = GBSerializedAudioFlagsSetCh2Hi(flags, audio->ch2.control.hi);
946 ch2Flags = GBSerializedAudioEnvelopeSetLength(ch2Flags, audio->ch2.control.length);
947 ch2Flags = GBSerializedAudioEnvelopeSetNextStep(ch2Flags, audio->ch2.envelope.nextStep);
948 STORE_32LE(ch2Flags, 0, &state->ch2.envelope);
949 STORE_32LE(audio->ch2Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch2.nextEvent);
950
951 flags = GBSerializedAudioFlagsSetCh3Readable(flags, audio->ch3.readable);
952 memcpy(state->ch3.wavebanks, audio->ch3.wavedata32, sizeof(state->ch3.wavebanks));
953 STORE_16LE(audio->ch3.length, 0, &state->ch3.length);
954 STORE_32LE(audio->ch3Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch3.nextEvent);
955 STORE_32LE(audio->ch3Fade.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextCh3Fade);
956
957 flags = GBSerializedAudioFlagsSetCh4Volume(flags, audio->ch4.envelope.currentVolume);
958 flags = GBSerializedAudioFlagsSetCh4Dead(flags, audio->ch4.envelope.dead);
959 STORE_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
960 ch4Flags = GBSerializedAudioEnvelopeSetLength(ch4Flags, audio->ch4.length);
961 ch4Flags = GBSerializedAudioEnvelopeSetNextStep(ch4Flags, audio->ch4.envelope.nextStep);
962 STORE_32LE(ch4Flags, 0, &state->ch4.envelope);
963 STORE_32LE(audio->ch4Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch4.nextEvent);
964
965 STORE_32LE(flags, 0, flagsOut);
966}
967
968void GBAudioPSGDeserialize(struct GBAudio* audio, const struct GBSerializedPSGState* state, const uint32_t* flagsIn) {
969 uint32_t flags;
970 uint32_t ch1Flags = 0;
971 uint32_t ch2Flags = 0;
972 uint32_t ch4Flags = 0;
973 uint32_t when;
974
975 audio->playingCh1 = !!(*audio->nr52 & 0x0001);
976 audio->playingCh2 = !!(*audio->nr52 & 0x0002);
977 audio->playingCh3 = !!(*audio->nr52 & 0x0004);
978 audio->playingCh4 = !!(*audio->nr52 & 0x0008);
979 audio->enable = GBAudioEnableGetEnable(*audio->nr52);
980
981 if (audio->style == GB_AUDIO_GBA) {
982 LOAD_32LE(when, 0, &state->ch1.nextFrame);
983 mTimingSchedule(audio->timing, &audio->frameEvent, when);
984 }
985
986 LOAD_32LE(flags, 0, flagsIn);
987 audio->frame = GBSerializedAudioFlagsGetFrame(flags);
988
989 LOAD_32LE(ch1Flags, 0, &state->ch1.envelope);
990 audio->ch1.envelope.currentVolume = GBSerializedAudioFlagsGetCh1Volume(flags);
991 audio->ch1.envelope.dead = GBSerializedAudioFlagsGetCh1Dead(flags);
992 audio->ch1.control.hi = GBSerializedAudioFlagsGetCh1Hi(flags);
993 audio->ch1.sweep.enable = GBSerializedAudioFlagsGetCh1SweepEnabled(flags);
994 audio->ch1.sweep.occurred = GBSerializedAudioFlagsGetCh1SweepOccurred(flags);
995 audio->ch1.control.length = GBSerializedAudioEnvelopeGetLength(ch1Flags);
996 audio->ch1.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch1Flags);
997 audio->ch1.sweep.realFrequency = GBSerializedAudioEnvelopeGetFrequency(ch1Flags);
998 LOAD_32LE(when, 0, &state->ch1.nextEvent);
999 if (audio->ch1.envelope.dead < 2 && audio->playingCh1) {
1000 mTimingSchedule(audio->timing, &audio->ch1Event, when);
1001 }
1002
1003 LOAD_32LE(ch2Flags, 0, &state->ch2.envelope);
1004 audio->ch2.envelope.currentVolume = GBSerializedAudioFlagsGetCh2Volume(flags);
1005 audio->ch2.envelope.dead = GBSerializedAudioFlagsGetCh2Dead(flags);
1006 audio->ch2.control.hi = GBSerializedAudioFlagsGetCh2Hi(flags);
1007 audio->ch2.control.length = GBSerializedAudioEnvelopeGetLength(ch2Flags);
1008 audio->ch2.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch2Flags);
1009 LOAD_32LE(when, 0, &state->ch2.nextEvent);
1010 if (audio->ch2.envelope.dead < 2 && audio->playingCh2) {
1011 mTimingSchedule(audio->timing, &audio->ch2Event, when);
1012 }
1013
1014 audio->ch3.readable = GBSerializedAudioFlagsGetCh3Readable(flags);
1015 // TODO: Big endian?
1016 memcpy(audio->ch3.wavedata32, state->ch3.wavebanks, sizeof(audio->ch3.wavedata32));
1017 LOAD_16LE(audio->ch3.length, 0, &state->ch3.length);
1018 LOAD_32LE(when, 0, &state->ch3.nextEvent);
1019 if (audio->playingCh3) {
1020 mTimingSchedule(audio->timing, &audio->ch3Event, when);
1021 }
1022 LOAD_32LE(when, 0, &state->ch1.nextCh3Fade);
1023 if (audio->ch3.readable && audio->style == GB_AUDIO_DMG) {
1024 mTimingSchedule(audio->timing, &audio->ch3Fade, when);
1025 }
1026
1027 LOAD_32LE(ch4Flags, 0, &state->ch4.envelope);
1028 audio->ch4.envelope.currentVolume = GBSerializedAudioFlagsGetCh4Volume(flags);
1029 audio->ch4.envelope.dead = GBSerializedAudioFlagsGetCh4Dead(flags);
1030 audio->ch4.length = GBSerializedAudioEnvelopeGetLength(ch4Flags);
1031 audio->ch4.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch4Flags);
1032 LOAD_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
1033 LOAD_32LE(when, 0, &state->ch4.nextEvent);
1034 if (audio->ch4.envelope.dead < 2 && audio->playingCh4) {
1035 mTimingSchedule(audio->timing, &audio->ch4Event, when);
1036 }
1037}
1038
1039void GBAudioSerialize(const struct GBAudio* audio, struct GBSerializedState* state) {
1040 GBAudioPSGSerialize(audio, &state->audio.psg, &state->audio.flags);
1041 STORE_32LE(audio->capLeft, 0, &state->audio.capLeft);
1042 STORE_32LE(audio->capRight, 0, &state->audio.capRight);
1043 STORE_32LE(audio->sampleEvent.when - mTimingCurrentTime(audio->timing), 0, &state->audio.nextSample);
1044}
1045
1046void GBAudioDeserialize(struct GBAudio* audio, const struct GBSerializedState* state) {
1047 GBAudioPSGDeserialize(audio, &state->audio.psg, &state->audio.flags);
1048 LOAD_32LE(audio->capLeft, 0, &state->audio.capLeft);
1049 LOAD_32LE(audio->capRight, 0, &state->audio.capRight);
1050 uint32_t when;
1051 LOAD_32LE(when, 0, &state->audio.nextSample);
1052 mTimingSchedule(audio->timing, &audio->sampleEvent, when);
1053}