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