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 int16_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->sampleEvent.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 _updateSquareChannel(&audio->ch1);
222 mTimingDeschedule(audio->timing, &audio->ch1Event);
223 mTimingSchedule(audio->timing, &audio->ch1Event, 0);
224 }
225 }
226 *audio->nr52 &= ~0x0001;
227 *audio->nr52 |= audio->playingCh1;
228}
229
230void GBAudioWriteNR21(struct GBAudio* audio, uint8_t value) {
231 _writeDuty(&audio->ch2.envelope, value);
232 audio->ch2.control.length = 64 - audio->ch2.envelope.length;
233}
234
235void GBAudioWriteNR22(struct GBAudio* audio, uint8_t value) {
236 if (!_writeEnvelope(&audio->ch2.envelope, value, audio->style)) {
237 mTimingDeschedule(audio->timing, &audio->ch2Event);
238 audio->playingCh2 = false;
239 *audio->nr52 &= ~0x0002;
240 }
241}
242
243void GBAudioWriteNR23(struct GBAudio* audio, uint8_t value) {
244 audio->ch2.control.frequency &= 0x700;
245 audio->ch2.control.frequency |= GBAudioRegisterControlGetFrequency(value);
246}
247
248void GBAudioWriteNR24(struct GBAudio* audio, uint8_t value) {
249 audio->ch2.control.frequency &= 0xFF;
250 audio->ch2.control.frequency |= GBAudioRegisterControlGetFrequency(value << 8);
251 bool wasStop = audio->ch2.control.stop;
252 audio->ch2.control.stop = GBAudioRegisterControlGetStop(value << 8);
253 if (!wasStop && audio->ch2.control.stop && audio->ch2.control.length && !(audio->frame & 1)) {
254 --audio->ch2.control.length;
255 if (audio->ch2.control.length == 0) {
256 mTimingDeschedule(audio->timing, &audio->ch2Event);
257 audio->playingCh2 = false;
258 }
259 }
260 if (GBAudioRegisterControlIsRestart(value << 8)) {
261 audio->playingCh2 = _resetEnvelope(&audio->ch2.envelope);
262
263 if (!audio->ch2.control.length) {
264 audio->ch2.control.length = 64;
265 if (audio->ch2.control.stop && !(audio->frame & 1)) {
266 --audio->ch2.control.length;
267 }
268 }
269 if (audio->playingCh2 && audio->ch2.envelope.dead != 2) {
270 _updateSquareChannel(&audio->ch2);
271 mTimingDeschedule(audio->timing, &audio->ch2Event);
272 mTimingSchedule(audio->timing, &audio->ch2Event, 0);
273 }
274 }
275 *audio->nr52 &= ~0x0002;
276 *audio->nr52 |= audio->playingCh2 << 1;
277}
278
279void GBAudioWriteNR30(struct GBAudio* audio, uint8_t value) {
280 audio->ch3.enable = GBAudioRegisterBankGetEnable(value);
281 if (!audio->ch3.enable) {
282 mTimingDeschedule(audio->timing, &audio->ch3Event);
283 audio->playingCh3 = false;
284 *audio->nr52 &= ~0x0004;
285 }
286}
287
288void GBAudioWriteNR31(struct GBAudio* audio, uint8_t value) {
289 audio->ch3.length = 256 - value;
290}
291
292void GBAudioWriteNR32(struct GBAudio* audio, uint8_t value) {
293 audio->ch3.volume = GBAudioRegisterBankVolumeGetVolumeGB(value);
294}
295
296void GBAudioWriteNR33(struct GBAudio* audio, uint8_t value) {
297 audio->ch3.rate &= 0x700;
298 audio->ch3.rate |= GBAudioRegisterControlGetRate(value);
299}
300
301void GBAudioWriteNR34(struct GBAudio* audio, uint8_t value) {
302 audio->ch3.rate &= 0xFF;
303 audio->ch3.rate |= GBAudioRegisterControlGetRate(value << 8);
304 bool wasStop = audio->ch3.stop;
305 audio->ch3.stop = GBAudioRegisterControlGetStop(value << 8);
306 if (!wasStop && audio->ch3.stop && audio->ch3.length && !(audio->frame & 1)) {
307 --audio->ch3.length;
308 if (audio->ch3.length == 0) {
309 audio->playingCh3 = false;
310 }
311 }
312 bool wasEnable = audio->playingCh3;
313 if (GBAudioRegisterControlIsRestart(value << 8)) {
314 audio->playingCh3 = audio->ch3.enable;
315 if (!audio->ch3.length) {
316 audio->ch3.length = 256;
317 if (audio->ch3.stop && !(audio->frame & 1)) {
318 --audio->ch3.length;
319 }
320 }
321
322 if (audio->style == GB_AUDIO_DMG && wasEnable && audio->playingCh3 && audio->ch3.readable) {
323 if (audio->ch3.window < 8) {
324 audio->ch3.wavedata8[0] = audio->ch3.wavedata8[audio->ch3.window >> 1];
325 } else {
326 audio->ch3.wavedata8[0] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3)];
327 audio->ch3.wavedata8[1] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 1];
328 audio->ch3.wavedata8[2] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 2];
329 audio->ch3.wavedata8[3] = audio->ch3.wavedata8[((audio->ch3.window >> 1) & ~3) + 3];
330 }
331 }
332 audio->ch3.window = 0;
333 if (audio->style == GB_AUDIO_DMG) {
334 audio->ch3.sample = 0;
335 }
336 }
337 mTimingDeschedule(audio->timing, &audio->ch3Fade);
338 mTimingDeschedule(audio->timing, &audio->ch3Event);
339 if (audio->playingCh3) {
340 audio->ch3.readable = audio->style != GB_AUDIO_DMG;
341 // TODO: Where does this cycle delay come from?
342 mTimingSchedule(audio->timing, &audio->ch3Event, audio->timingFactor * 4 + 2 * (2048 - audio->ch3.rate));
343 }
344 *audio->nr52 &= ~0x0004;
345 *audio->nr52 |= audio->playingCh3 << 2;
346}
347
348void GBAudioWriteNR41(struct GBAudio* audio, uint8_t value) {
349 _writeDuty(&audio->ch4.envelope, value);
350 audio->ch4.length = 64 - audio->ch4.envelope.length;
351}
352
353void GBAudioWriteNR42(struct GBAudio* audio, uint8_t value) {
354 if (!_writeEnvelope(&audio->ch4.envelope, value, audio->style)) {
355 mTimingDeschedule(audio->timing, &audio->ch4Event);
356 audio->playingCh4 = false;
357 *audio->nr52 &= ~0x0008;
358 }
359}
360
361void GBAudioWriteNR43(struct GBAudio* audio, uint8_t value) {
362 audio->ch4.ratio = GBAudioRegisterNoiseFeedbackGetRatio(value);
363 audio->ch4.frequency = GBAudioRegisterNoiseFeedbackGetFrequency(value);
364 audio->ch4.power = GBAudioRegisterNoiseFeedbackGetPower(value);
365}
366
367void GBAudioWriteNR44(struct GBAudio* audio, uint8_t value) {
368 bool wasStop = audio->ch4.stop;
369 audio->ch4.stop = GBAudioRegisterNoiseControlGetStop(value);
370 if (!wasStop && audio->ch4.stop && audio->ch4.length && !(audio->frame & 1)) {
371 --audio->ch4.length;
372 if (audio->ch4.length == 0) {
373 mTimingDeschedule(audio->timing, &audio->ch4Event);
374 audio->playingCh4 = false;
375 }
376 }
377 if (GBAudioRegisterNoiseControlIsRestart(value)) {
378 audio->playingCh4 = _resetEnvelope(&audio->ch4.envelope);
379
380 if (audio->ch4.power) {
381 audio->ch4.lfsr = 0x7F;
382 } else {
383 audio->ch4.lfsr = 0x7FFF;
384 }
385 if (!audio->ch4.length) {
386 audio->ch4.length = 64;
387 if (audio->ch4.stop && !(audio->frame & 1)) {
388 --audio->ch4.length;
389 }
390 }
391 if (audio->playingCh4 && audio->ch4.envelope.dead != 2) {
392 mTimingDeschedule(audio->timing, &audio->ch4Event);
393 mTimingSchedule(audio->timing, &audio->ch4Event, 0);
394 }
395 }
396 *audio->nr52 &= ~0x0008;
397 *audio->nr52 |= audio->playingCh4 << 3;
398}
399
400void GBAudioWriteNR50(struct GBAudio* audio, uint8_t value) {
401 audio->volumeRight = GBRegisterNR50GetVolumeRight(value);
402 audio->volumeLeft = GBRegisterNR50GetVolumeLeft(value);
403}
404
405void GBAudioWriteNR51(struct GBAudio* audio, uint8_t value) {
406 audio->ch1Right = GBRegisterNR51GetCh1Right(value);
407 audio->ch2Right = GBRegisterNR51GetCh2Right(value);
408 audio->ch3Right = GBRegisterNR51GetCh3Right(value);
409 audio->ch4Right = GBRegisterNR51GetCh4Right(value);
410 audio->ch1Left = GBRegisterNR51GetCh1Left(value);
411 audio->ch2Left = GBRegisterNR51GetCh2Left(value);
412 audio->ch3Left = GBRegisterNR51GetCh3Left(value);
413 audio->ch4Left = GBRegisterNR51GetCh4Left(value);
414}
415
416void GBAudioWriteNR52(struct GBAudio* audio, uint8_t value) {
417 bool wasEnable = audio->enable;
418 audio->enable = GBAudioEnableGetEnable(value);
419 if (!audio->enable) {
420 audio->playingCh1 = 0;
421 audio->playingCh2 = 0;
422 audio->playingCh3 = 0;
423 audio->playingCh4 = 0;
424 GBAudioWriteNR10(audio, 0);
425 GBAudioWriteNR12(audio, 0);
426 GBAudioWriteNR13(audio, 0);
427 GBAudioWriteNR14(audio, 0);
428 GBAudioWriteNR22(audio, 0);
429 GBAudioWriteNR23(audio, 0);
430 GBAudioWriteNR24(audio, 0);
431 GBAudioWriteNR30(audio, 0);
432 GBAudioWriteNR32(audio, 0);
433 GBAudioWriteNR33(audio, 0);
434 GBAudioWriteNR34(audio, 0);
435 GBAudioWriteNR42(audio, 0);
436 GBAudioWriteNR43(audio, 0);
437 GBAudioWriteNR44(audio, 0);
438 GBAudioWriteNR50(audio, 0);
439 GBAudioWriteNR51(audio, 0);
440 if (audio->style != GB_AUDIO_DMG) {
441 GBAudioWriteNR11(audio, 0);
442 GBAudioWriteNR21(audio, 0);
443 GBAudioWriteNR31(audio, 0);
444 GBAudioWriteNR41(audio, 0);
445 }
446
447 if (audio->p) {
448 audio->p->memory.io[REG_NR10] = 0;
449 audio->p->memory.io[REG_NR11] = 0;
450 audio->p->memory.io[REG_NR12] = 0;
451 audio->p->memory.io[REG_NR13] = 0;
452 audio->p->memory.io[REG_NR14] = 0;
453 audio->p->memory.io[REG_NR21] = 0;
454 audio->p->memory.io[REG_NR22] = 0;
455 audio->p->memory.io[REG_NR23] = 0;
456 audio->p->memory.io[REG_NR24] = 0;
457 audio->p->memory.io[REG_NR30] = 0;
458 audio->p->memory.io[REG_NR31] = 0;
459 audio->p->memory.io[REG_NR32] = 0;
460 audio->p->memory.io[REG_NR33] = 0;
461 audio->p->memory.io[REG_NR34] = 0;
462 audio->p->memory.io[REG_NR42] = 0;
463 audio->p->memory.io[REG_NR43] = 0;
464 audio->p->memory.io[REG_NR44] = 0;
465 audio->p->memory.io[REG_NR50] = 0;
466 audio->p->memory.io[REG_NR51] = 0;
467 if (audio->style != GB_AUDIO_DMG) {
468 audio->p->memory.io[REG_NR11] = 0;
469 audio->p->memory.io[REG_NR21] = 0;
470 audio->p->memory.io[REG_NR31] = 0;
471 audio->p->memory.io[REG_NR41] = 0;
472 }
473 }
474 *audio->nr52 &= ~0x000F;
475 } else if (!wasEnable) {
476 audio->skipFrame = false;
477 audio->frame = 7;
478
479 if (audio->p) {
480 unsigned timingFactor = 0x400 >> !audio->p->doubleSpeed;
481 if (audio->p->timer.internalDiv & timingFactor) {
482 audio->skipFrame = true;
483 }
484 }
485 }
486}
487
488void _updateFrame(struct mTiming* timing, void* user, uint32_t cyclesLate) {
489 struct GBAudio* audio = user;
490 GBAudioUpdateFrame(audio, timing);
491 if (audio->style == GB_AUDIO_GBA) {
492 mTimingSchedule(timing, &audio->frameEvent, audio->timingFactor * FRAME_CYCLES - cyclesLate);
493 }
494}
495
496void GBAudioUpdateFrame(struct GBAudio* audio, struct mTiming* timing) {
497 if (!audio->enable) {
498 return;
499 }
500 if (audio->skipFrame) {
501 audio->skipFrame = false;
502 return;
503 }
504 int frame = (audio->frame + 1) & 7;
505 audio->frame = frame;
506
507 switch (frame) {
508 case 2:
509 case 6:
510 if (audio->ch1.sweep.enable) {
511 --audio->ch1.sweep.step;
512 if (audio->ch1.sweep.step == 0) {
513 audio->playingCh1 = _updateSweep(&audio->ch1, false);
514 *audio->nr52 &= ~0x0001;
515 *audio->nr52 |= audio->playingCh1;
516 if (!audio->playingCh1) {
517 mTimingDeschedule(audio->timing, &audio->ch1Event);
518 }
519 }
520 }
521 // Fall through
522 case 0:
523 case 4:
524 if (audio->ch1.control.length && audio->ch1.control.stop) {
525 --audio->ch1.control.length;
526 if (audio->ch1.control.length == 0) {
527 mTimingDeschedule(timing, &audio->ch1Event);
528 audio->playingCh1 = 0;
529 *audio->nr52 &= ~0x0001;
530 }
531 }
532
533 if (audio->ch2.control.length && audio->ch2.control.stop) {
534 --audio->ch2.control.length;
535 if (audio->ch2.control.length == 0) {
536 mTimingDeschedule(timing, &audio->ch2Event);
537 audio->playingCh2 = 0;
538 *audio->nr52 &= ~0x0002;
539 }
540 }
541
542 if (audio->ch3.length && audio->ch3.stop) {
543 --audio->ch3.length;
544 if (audio->ch3.length == 0) {
545 mTimingDeschedule(timing, &audio->ch3Event);
546 audio->playingCh3 = 0;
547 *audio->nr52 &= ~0x0004;
548 }
549 }
550
551 if (audio->ch4.length && audio->ch4.stop) {
552 --audio->ch4.length;
553 if (audio->ch4.length == 0) {
554 mTimingDeschedule(timing, &audio->ch4Event);
555 audio->playingCh4 = 0;
556 *audio->nr52 &= ~0x0008;
557 }
558 }
559 break;
560 case 7:
561 if (audio->playingCh1 && !audio->ch1.envelope.dead) {
562 --audio->ch1.envelope.nextStep;
563 if (audio->ch1.envelope.nextStep == 0) {
564 _updateEnvelope(&audio->ch1.envelope);
565 if (audio->ch1.envelope.dead == 2) {
566 mTimingDeschedule(timing, &audio->ch1Event);
567 }
568 _updateSquareSample(&audio->ch1);
569 }
570 }
571
572 if (audio->playingCh2 && !audio->ch2.envelope.dead) {
573 --audio->ch2.envelope.nextStep;
574 if (audio->ch2.envelope.nextStep == 0) {
575 _updateEnvelope(&audio->ch2.envelope);
576 if (audio->ch2.envelope.dead == 2) {
577 mTimingDeschedule(timing, &audio->ch2Event);
578 }
579 _updateSquareSample(&audio->ch2);
580 }
581 }
582
583 if (audio->playingCh4 && !audio->ch4.envelope.dead) {
584 --audio->ch4.envelope.nextStep;
585 if (audio->ch4.envelope.nextStep == 0) {
586 int8_t sample = audio->ch4.sample > 0;
587 audio->ch4.samples -= audio->ch4.sample;
588 _updateEnvelope(&audio->ch4.envelope);
589 if (audio->ch4.envelope.dead == 2) {
590 mTimingDeschedule(timing, &audio->ch4Event);
591 }
592 audio->ch4.sample = sample * audio->ch4.envelope.currentVolume;
593 audio->ch4.samples += audio->ch4.sample;
594 }
595 }
596 break;
597 }
598}
599
600void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right) {
601 int dcOffset = audio->style == GB_AUDIO_GBA ? 0 : -0x8;
602 int sampleLeft = dcOffset;
603 int sampleRight = dcOffset;
604
605 if (!audio->forceDisableCh[0]) {
606 if (audio->ch1Left) {
607 sampleLeft += audio->ch1.sample;
608 }
609
610 if (audio->ch1Right) {
611 sampleRight += audio->ch1.sample;
612 }
613 }
614
615 if (!audio->forceDisableCh[1]) {
616 if (audio->ch2Left) {
617 sampleLeft += audio->ch2.sample;
618 }
619
620 if (audio->ch2Right) {
621 sampleRight += audio->ch2.sample;
622 }
623 }
624
625 if (!audio->forceDisableCh[2]) {
626 if (audio->ch3Left) {
627 sampleLeft += audio->ch3.sample;
628 }
629
630 if (audio->ch3Right) {
631 sampleRight += audio->ch3.sample;
632 }
633 }
634
635 sampleLeft <<= 3;
636 sampleRight <<= 3;
637
638 if (!audio->forceDisableCh[3]) {
639 int16_t sample = audio->style == GB_AUDIO_GBA ? (audio->ch4.sample << 3) : _coalesceNoiseChannel(&audio->ch4);
640 if (audio->ch4Left) {
641 sampleLeft += sample;
642 }
643
644 if (audio->ch4Right) {
645 sampleRight += sample;
646 }
647 }
648
649 *left = sampleLeft * (1 + audio->volumeLeft);
650 *right = sampleRight * (1 + audio->volumeRight);
651}
652
653static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate) {
654 struct GBAudio* audio = user;
655 int16_t sampleLeft = 0;
656 int16_t sampleRight = 0;
657 GBAudioSamplePSG(audio, &sampleLeft, &sampleRight);
658 sampleLeft = (sampleLeft * audio->masterVolume * 6) >> 7;
659 sampleRight = (sampleRight * audio->masterVolume * 6) >> 7;
660
661 mCoreSyncLockAudio(audio->p->sync);
662 unsigned produced;
663
664 int16_t degradedLeft = sampleLeft - (audio->capLeft >> 16);
665 int16_t degradedRight = sampleRight - (audio->capRight >> 16);
666 audio->capLeft = (sampleLeft << 16) - degradedLeft * 65184;
667 audio->capRight = (sampleRight << 16) - degradedRight * 65184;
668 sampleLeft = degradedLeft;
669 sampleRight = degradedRight;
670
671 if ((size_t) blip_samples_avail(audio->left) < audio->samples) {
672 blip_add_delta(audio->left, audio->clock, sampleLeft - audio->lastLeft);
673 blip_add_delta(audio->right, audio->clock, sampleRight - audio->lastRight);
674 audio->lastLeft = sampleLeft;
675 audio->lastRight = sampleRight;
676 audio->clock += audio->sampleInterval;
677 if (audio->clock >= CLOCKS_PER_BLIP_FRAME) {
678 blip_end_frame(audio->left, CLOCKS_PER_BLIP_FRAME);
679 blip_end_frame(audio->right, CLOCKS_PER_BLIP_FRAME);
680 audio->clock -= CLOCKS_PER_BLIP_FRAME;
681 }
682 }
683 produced = blip_samples_avail(audio->left);
684 if (audio->p->stream && audio->p->stream->postAudioFrame) {
685 audio->p->stream->postAudioFrame(audio->p->stream, sampleLeft, sampleRight);
686 }
687 bool wait = produced >= audio->samples;
688 if (!mCoreSyncProduceAudio(audio->p->sync, audio->left, audio->samples)) {
689 // Interrupted
690 audio->p->earlyExit = true;
691 }
692
693 if (wait && audio->p->stream && audio->p->stream->postAudioBuffer) {
694 audio->p->stream->postAudioBuffer(audio->p->stream, audio->left, audio->right);
695 }
696 mTimingSchedule(timing, &audio->sampleEvent, audio->sampleInterval * audio->timingFactor - cyclesLate);
697}
698
699bool _resetEnvelope(struct GBAudioEnvelope* envelope) {
700 envelope->currentVolume = envelope->initialVolume;
701 _updateEnvelopeDead(envelope);
702 if (!envelope->dead) {
703 envelope->nextStep = envelope->stepTime;
704 }
705 return envelope->initialVolume || envelope->direction;
706}
707
708void _resetSweep(struct GBAudioSweep* sweep) {
709 sweep->step = sweep->time;
710 sweep->enable = (sweep->step != 8) || sweep->shift;
711 sweep->occurred = false;
712}
713
714bool _writeSweep(struct GBAudioSweep* sweep, uint8_t value) {
715 sweep->shift = GBAudioRegisterSquareSweepGetShift(value);
716 bool oldDirection = sweep->direction;
717 sweep->direction = GBAudioRegisterSquareSweepGetDirection(value);
718 bool on = true;
719 if (sweep->occurred && oldDirection && !sweep->direction) {
720 on = false;
721 }
722 sweep->occurred = false;
723 sweep->time = GBAudioRegisterSquareSweepGetTime(value);
724 if (!sweep->time) {
725 sweep->time = 8;
726 }
727 return on;
728}
729
730void _writeDuty(struct GBAudioEnvelope* envelope, uint8_t value) {
731 envelope->length = GBAudioRegisterDutyGetLength(value);
732 envelope->duty = GBAudioRegisterDutyGetDuty(value);
733}
734
735bool _writeEnvelope(struct GBAudioEnvelope* envelope, uint8_t value, enum GBAudioStyle style) {
736 envelope->stepTime = GBAudioRegisterSweepGetStepTime(value);
737 envelope->direction = GBAudioRegisterSweepGetDirection(value);
738 envelope->initialVolume = GBAudioRegisterSweepGetInitialVolume(value);
739 if (style == GB_AUDIO_DMG && !envelope->stepTime) {
740 // TODO: Improve "zombie" mode
741 ++envelope->currentVolume;
742 envelope->currentVolume &= 0xF;
743 }
744 _updateEnvelopeDead(envelope);
745 return (envelope->initialVolume || envelope->direction) && envelope->dead != 2;
746}
747
748static void _updateSquareSample(struct GBAudioSquareChannel* ch) {
749 ch->sample = ch->control.hi * ch->envelope.currentVolume;
750}
751
752static int32_t _updateSquareChannel(struct GBAudioSquareChannel* ch) {
753 ch->control.hi = !ch->control.hi;
754 _updateSquareSample(ch);
755 int period = 4 * (2048 - ch->control.frequency);
756 switch (ch->envelope.duty) {
757 case 0:
758 return ch->control.hi ? period : period * 7;
759 case 1:
760 return ch->control.hi ? period * 2 : period * 6;
761 case 2:
762 return period * 4;
763 case 3:
764 return ch->control.hi ? period * 6 : period * 2;
765 default:
766 // This should never be hit
767 return period * 4;
768 }
769}
770
771static int16_t _coalesceNoiseChannel(struct GBAudioNoiseChannel* ch) {
772 if (!ch->nSamples) {
773 return ch->sample << 3;
774 }
775 // TODO keep track of timing
776 int16_t sample = (ch->samples << 3) / ch->nSamples;
777 ch->nSamples = 0;
778 ch->samples = 0;
779 return sample;
780}
781
782static void _updateEnvelope(struct GBAudioEnvelope* envelope) {
783 if (envelope->direction) {
784 ++envelope->currentVolume;
785 } else {
786 --envelope->currentVolume;
787 }
788 if (envelope->currentVolume >= 15) {
789 envelope->currentVolume = 15;
790 envelope->dead = 1;
791 } else if (envelope->currentVolume <= 0) {
792 envelope->currentVolume = 0;
793 envelope->dead = 2;
794 } else {
795 envelope->nextStep = envelope->stepTime;
796 }
797}
798
799static void _updateEnvelopeDead(struct GBAudioEnvelope* envelope) {
800 if (!envelope->stepTime) {
801 envelope->dead = envelope->currentVolume ? 1 : 2;
802 } else if (!envelope->direction && !envelope->currentVolume) {
803 envelope->dead = 2;
804 } else if (envelope->direction && envelope->currentVolume == 0xF) {
805 envelope->dead = 1;
806 } else {
807 envelope->dead = 0;
808 }
809}
810
811static bool _updateSweep(struct GBAudioSquareChannel* ch, bool initial) {
812 if (initial || ch->sweep.time != 8) {
813 int frequency = ch->sweep.realFrequency;
814 if (ch->sweep.direction) {
815 frequency -= frequency >> ch->sweep.shift;
816 if (!initial && frequency >= 0) {
817 ch->control.frequency = frequency;
818 ch->sweep.realFrequency = frequency;
819 }
820 } else {
821 frequency += frequency >> ch->sweep.shift;
822 if (frequency < 2048) {
823 if (!initial && ch->sweep.shift) {
824 ch->control.frequency = frequency;
825 ch->sweep.realFrequency = frequency;
826 if (!_updateSweep(ch, true)) {
827 return false;
828 }
829 }
830 } else {
831 return false;
832 }
833 }
834 ch->sweep.occurred = true;
835 }
836 ch->sweep.step = ch->sweep.time;
837 return true;
838}
839
840static void _updateChannel1(struct mTiming* timing, void* user, uint32_t cyclesLate) {
841 struct GBAudio* audio = user;
842 struct GBAudioSquareChannel* ch = &audio->ch1;
843 int cycles = _updateSquareChannel(ch);
844 mTimingSchedule(timing, &audio->ch1Event, audio->timingFactor * cycles - cyclesLate);
845}
846
847static void _updateChannel2(struct mTiming* timing, void* user, uint32_t cyclesLate) {
848 struct GBAudio* audio = user;
849 struct GBAudioSquareChannel* ch = &audio->ch2;
850 int cycles = _updateSquareChannel(ch);
851 mTimingSchedule(timing, &audio->ch2Event, audio->timingFactor * cycles - cyclesLate);
852}
853
854static void _updateChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
855 struct GBAudio* audio = user;
856 struct GBAudioWaveChannel* ch = &audio->ch3;
857 int i;
858 int volume;
859 switch (ch->volume) {
860 case 0:
861 volume = 4;
862 break;
863 case 1:
864 volume = 0;
865 break;
866 case 2:
867 volume = 1;
868 break;
869 default:
870 case 3:
871 volume = 2;
872 break;
873 }
874 int start;
875 int end;
876 switch (audio->style) {
877 case GB_AUDIO_DMG:
878 default:
879 ++ch->window;
880 ch->window &= 0x1F;
881 ch->sample = ch->wavedata8[ch->window >> 1];
882 if (!(ch->window & 1)) {
883 ch->sample >>= 4;
884 }
885 ch->sample &= 0xF;
886 break;
887 case GB_AUDIO_GBA:
888 if (ch->size) {
889 start = 7;
890 end = 0;
891 } else if (ch->bank) {
892 start = 7;
893 end = 4;
894 } else {
895 start = 3;
896 end = 0;
897 }
898 uint32_t bitsCarry = ch->wavedata32[end] & 0x000000F0;
899 uint32_t bits;
900 for (i = start; i >= end; --i) {
901 bits = ch->wavedata32[i] & 0x000000F0;
902 ch->wavedata32[i] = ((ch->wavedata32[i] & 0x0F0F0F0F) << 4) | ((ch->wavedata32[i] & 0xF0F0F000) >> 12);
903 ch->wavedata32[i] |= bitsCarry << 20;
904 bitsCarry = bits;
905 }
906 ch->sample = bitsCarry >> 4;
907 break;
908 }
909 if (ch->volume > 3) {
910 ch->sample += ch->sample << 1;
911 }
912 ch->sample >>= volume;
913 audio->ch3.readable = true;
914 if (audio->style == GB_AUDIO_DMG) {
915 mTimingDeschedule(audio->timing, &audio->ch3Fade);
916 mTimingSchedule(timing, &audio->ch3Fade, 2 - cyclesLate);
917 }
918 int cycles = 2 * (2048 - ch->rate);
919 mTimingSchedule(timing, &audio->ch3Event, audio->timingFactor * cycles - cyclesLate);
920}
921static void _fadeChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
922 UNUSED(timing);
923 UNUSED(cyclesLate);
924 struct GBAudio* audio = user;
925 audio->ch3.readable = false;
926}
927
928static void _updateChannel4(struct mTiming* timing, void* user, uint32_t cyclesLate) {
929 struct GBAudio* audio = user;
930 struct GBAudioNoiseChannel* ch = &audio->ch4;
931
932 int32_t cycles = ch->ratio ? 2 * ch->ratio : 1;
933 cycles <<= ch->frequency;
934 cycles *= 8 * audio->timingFactor;
935
936 int lsb = ch->lfsr & 1;
937 ch->sample = lsb * ch->envelope.currentVolume;
938 ++ch->nSamples;
939 ch->samples += ch->sample;
940 ch->lfsr >>= 1;
941 ch->lfsr ^= (lsb * 0x60) << (ch->power ? 0 : 8);
942
943 mTimingSchedule(timing, &audio->ch4Event, cycles - cyclesLate);
944}
945
946void GBAudioPSGSerialize(const struct GBAudio* audio, struct GBSerializedPSGState* state, uint32_t* flagsOut) {
947 uint32_t flags = 0;
948 uint32_t ch1Flags = 0;
949 uint32_t ch2Flags = 0;
950 uint32_t ch4Flags = 0;
951
952 flags = GBSerializedAudioFlagsSetFrame(flags, audio->frame);
953 flags = GBSerializedAudioFlagsSetSkipFrame(flags, audio->skipFrame);
954 STORE_32LE(audio->frameEvent.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextFrame);
955
956 flags = GBSerializedAudioFlagsSetCh1Volume(flags, audio->ch1.envelope.currentVolume);
957 flags = GBSerializedAudioFlagsSetCh1Dead(flags, audio->ch1.envelope.dead);
958 flags = GBSerializedAudioFlagsSetCh1Hi(flags, audio->ch1.control.hi);
959 flags = GBSerializedAudioFlagsSetCh1SweepEnabled(flags, audio->ch1.sweep.enable);
960 flags = GBSerializedAudioFlagsSetCh1SweepOccurred(flags, audio->ch1.sweep.occurred);
961 ch1Flags = GBSerializedAudioEnvelopeSetLength(ch1Flags, audio->ch1.control.length);
962 ch1Flags = GBSerializedAudioEnvelopeSetNextStep(ch1Flags, audio->ch1.envelope.nextStep);
963 ch1Flags = GBSerializedAudioEnvelopeSetFrequency(ch1Flags, audio->ch1.sweep.realFrequency);
964 STORE_32LE(ch1Flags, 0, &state->ch1.envelope);
965 STORE_32LE(audio->ch1Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextEvent);
966
967 flags = GBSerializedAudioFlagsSetCh2Volume(flags, audio->ch2.envelope.currentVolume);
968 flags = GBSerializedAudioFlagsSetCh2Dead(flags, audio->ch2.envelope.dead);
969 flags = GBSerializedAudioFlagsSetCh2Hi(flags, audio->ch2.control.hi);
970 ch2Flags = GBSerializedAudioEnvelopeSetLength(ch2Flags, audio->ch2.control.length);
971 ch2Flags = GBSerializedAudioEnvelopeSetNextStep(ch2Flags, audio->ch2.envelope.nextStep);
972 STORE_32LE(ch2Flags, 0, &state->ch2.envelope);
973 STORE_32LE(audio->ch2Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch2.nextEvent);
974
975 flags = GBSerializedAudioFlagsSetCh3Readable(flags, audio->ch3.readable);
976 memcpy(state->ch3.wavebanks, audio->ch3.wavedata32, sizeof(state->ch3.wavebanks));
977 STORE_16LE(audio->ch3.length, 0, &state->ch3.length);
978 STORE_32LE(audio->ch3Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch3.nextEvent);
979 STORE_32LE(audio->ch3Fade.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextCh3Fade);
980
981 flags = GBSerializedAudioFlagsSetCh4Volume(flags, audio->ch4.envelope.currentVolume);
982 flags = GBSerializedAudioFlagsSetCh4Dead(flags, audio->ch4.envelope.dead);
983 STORE_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
984 ch4Flags = GBSerializedAudioEnvelopeSetLength(ch4Flags, audio->ch4.length);
985 ch4Flags = GBSerializedAudioEnvelopeSetNextStep(ch4Flags, audio->ch4.envelope.nextStep);
986 STORE_32LE(ch4Flags, 0, &state->ch4.envelope);
987 STORE_32LE(audio->ch4Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch4.nextEvent);
988
989 STORE_32LE(flags, 0, flagsOut);
990}
991
992void GBAudioPSGDeserialize(struct GBAudio* audio, const struct GBSerializedPSGState* state, const uint32_t* flagsIn) {
993 uint32_t flags;
994 uint32_t ch1Flags = 0;
995 uint32_t ch2Flags = 0;
996 uint32_t ch4Flags = 0;
997 uint32_t when;
998
999 audio->playingCh1 = !!(*audio->nr52 & 0x0001);
1000 audio->playingCh2 = !!(*audio->nr52 & 0x0002);
1001 audio->playingCh3 = !!(*audio->nr52 & 0x0004);
1002 audio->playingCh4 = !!(*audio->nr52 & 0x0008);
1003 audio->enable = GBAudioEnableGetEnable(*audio->nr52);
1004
1005 if (audio->style == GB_AUDIO_GBA) {
1006 LOAD_32LE(when, 0, &state->ch1.nextFrame);
1007 mTimingSchedule(audio->timing, &audio->frameEvent, when);
1008 }
1009
1010 LOAD_32LE(flags, 0, flagsIn);
1011 audio->frame = GBSerializedAudioFlagsGetFrame(flags);
1012 audio->skipFrame = GBSerializedAudioFlagsGetSkipFrame(flags);
1013
1014 LOAD_32LE(ch1Flags, 0, &state->ch1.envelope);
1015 audio->ch1.envelope.currentVolume = GBSerializedAudioFlagsGetCh1Volume(flags);
1016 audio->ch1.envelope.dead = GBSerializedAudioFlagsGetCh1Dead(flags);
1017 audio->ch1.control.hi = GBSerializedAudioFlagsGetCh1Hi(flags);
1018 audio->ch1.sweep.enable = GBSerializedAudioFlagsGetCh1SweepEnabled(flags);
1019 audio->ch1.sweep.occurred = GBSerializedAudioFlagsGetCh1SweepOccurred(flags);
1020 audio->ch1.control.length = GBSerializedAudioEnvelopeGetLength(ch1Flags);
1021 audio->ch1.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch1Flags);
1022 audio->ch1.sweep.realFrequency = GBSerializedAudioEnvelopeGetFrequency(ch1Flags);
1023 LOAD_32LE(when, 0, &state->ch1.nextEvent);
1024 if (audio->ch1.envelope.dead < 2 && audio->playingCh1) {
1025 mTimingSchedule(audio->timing, &audio->ch1Event, when);
1026 }
1027
1028 LOAD_32LE(ch2Flags, 0, &state->ch2.envelope);
1029 audio->ch2.envelope.currentVolume = GBSerializedAudioFlagsGetCh2Volume(flags);
1030 audio->ch2.envelope.dead = GBSerializedAudioFlagsGetCh2Dead(flags);
1031 audio->ch2.control.hi = GBSerializedAudioFlagsGetCh2Hi(flags);
1032 audio->ch2.control.length = GBSerializedAudioEnvelopeGetLength(ch2Flags);
1033 audio->ch2.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch2Flags);
1034 LOAD_32LE(when, 0, &state->ch2.nextEvent);
1035 if (audio->ch2.envelope.dead < 2 && audio->playingCh2) {
1036 mTimingSchedule(audio->timing, &audio->ch2Event, when);
1037 }
1038
1039 audio->ch3.readable = GBSerializedAudioFlagsGetCh3Readable(flags);
1040 // TODO: Big endian?
1041 memcpy(audio->ch3.wavedata32, state->ch3.wavebanks, sizeof(audio->ch3.wavedata32));
1042 LOAD_16LE(audio->ch3.length, 0, &state->ch3.length);
1043 LOAD_32LE(when, 0, &state->ch3.nextEvent);
1044 if (audio->playingCh3) {
1045 mTimingSchedule(audio->timing, &audio->ch3Event, when);
1046 }
1047 LOAD_32LE(when, 0, &state->ch1.nextCh3Fade);
1048 if (audio->ch3.readable && audio->style == GB_AUDIO_DMG) {
1049 mTimingSchedule(audio->timing, &audio->ch3Fade, when);
1050 }
1051
1052 LOAD_32LE(ch4Flags, 0, &state->ch4.envelope);
1053 audio->ch4.envelope.currentVolume = GBSerializedAudioFlagsGetCh4Volume(flags);
1054 audio->ch4.envelope.dead = GBSerializedAudioFlagsGetCh4Dead(flags);
1055 audio->ch4.length = GBSerializedAudioEnvelopeGetLength(ch4Flags);
1056 audio->ch4.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch4Flags);
1057 LOAD_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
1058 LOAD_32LE(when, 0, &state->ch4.nextEvent);
1059 if (audio->ch4.envelope.dead < 2 && audio->playingCh4) {
1060 mTimingSchedule(audio->timing, &audio->ch4Event, when);
1061 }
1062}
1063
1064void GBAudioSerialize(const struct GBAudio* audio, struct GBSerializedState* state) {
1065 GBAudioPSGSerialize(audio, &state->audio.psg, &state->audio.flags);
1066 STORE_32LE(audio->capLeft, 0, &state->audio.capLeft);
1067 STORE_32LE(audio->capRight, 0, &state->audio.capRight);
1068 STORE_32LE(audio->sampleEvent.when - mTimingCurrentTime(audio->timing), 0, &state->audio.nextSample);
1069}
1070
1071void GBAudioDeserialize(struct GBAudio* audio, const struct GBSerializedState* state) {
1072 GBAudioPSGDeserialize(audio, &state->audio.psg, &state->audio.flags);
1073 LOAD_32LE(audio->capLeft, 0, &state->audio.capLeft);
1074 LOAD_32LE(audio->capRight, 0, &state->audio.capRight);
1075 uint32_t when;
1076 LOAD_32LE(when, 0, &state->audio.nextSample);
1077 mTimingSchedule(audio->timing, &audio->sampleEvent, when);
1078}