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