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_SM83_FREQUENCY >> 9)
20
21const uint32_t DMG_SM83_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_SM83_FREQUENCY;
55 // Guess too large; we hang producing extra samples if we guess too low
56 blip_set_rates(audio->left, DMG_SM83_FREQUENCY, 96000);
57 blip_set_rates(audio->right, DMG_SM83_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 // TODO: Reschedule event
363 audio->ch4.ratio = GBAudioRegisterNoiseFeedbackGetRatio(value);
364 audio->ch4.frequency = GBAudioRegisterNoiseFeedbackGetFrequency(value);
365 audio->ch4.power = GBAudioRegisterNoiseFeedbackGetPower(value);
366}
367
368void GBAudioWriteNR44(struct GBAudio* audio, uint8_t value) {
369 bool wasStop = audio->ch4.stop;
370 audio->ch4.stop = GBAudioRegisterNoiseControlGetStop(value);
371 if (!wasStop && audio->ch4.stop && audio->ch4.length && !(audio->frame & 1)) {
372 --audio->ch4.length;
373 if (audio->ch4.length == 0) {
374 mTimingDeschedule(audio->timing, &audio->ch4Event);
375 audio->playingCh4 = false;
376 }
377 }
378 if (GBAudioRegisterNoiseControlIsRestart(value)) {
379 audio->playingCh4 = _resetEnvelope(&audio->ch4.envelope);
380
381 if (audio->ch4.power) {
382 audio->ch4.lfsr = 0x7F;
383 } else {
384 audio->ch4.lfsr = 0x7FFF;
385 }
386 if (!audio->ch4.length) {
387 audio->ch4.length = 64;
388 if (audio->ch4.stop && !(audio->frame & 1)) {
389 --audio->ch4.length;
390 }
391 }
392 if (audio->playingCh4 && audio->ch4.envelope.dead != 2) {
393 mTimingDeschedule(audio->timing, &audio->ch4Event);
394 mTimingSchedule(audio->timing, &audio->ch4Event, 0);
395 }
396 }
397 *audio->nr52 &= ~0x0008;
398 *audio->nr52 |= audio->playingCh4 << 3;
399}
400
401void GBAudioWriteNR50(struct GBAudio* audio, uint8_t value) {
402 audio->volumeRight = GBRegisterNR50GetVolumeRight(value);
403 audio->volumeLeft = GBRegisterNR50GetVolumeLeft(value);
404}
405
406void GBAudioWriteNR51(struct GBAudio* audio, uint8_t value) {
407 audio->ch1Right = GBRegisterNR51GetCh1Right(value);
408 audio->ch2Right = GBRegisterNR51GetCh2Right(value);
409 audio->ch3Right = GBRegisterNR51GetCh3Right(value);
410 audio->ch4Right = GBRegisterNR51GetCh4Right(value);
411 audio->ch1Left = GBRegisterNR51GetCh1Left(value);
412 audio->ch2Left = GBRegisterNR51GetCh2Left(value);
413 audio->ch3Left = GBRegisterNR51GetCh3Left(value);
414 audio->ch4Left = GBRegisterNR51GetCh4Left(value);
415}
416
417void GBAudioWriteNR52(struct GBAudio* audio, uint8_t value) {
418 bool wasEnable = audio->enable;
419 audio->enable = GBAudioEnableGetEnable(value);
420 if (!audio->enable) {
421 audio->playingCh1 = 0;
422 audio->playingCh2 = 0;
423 audio->playingCh3 = 0;
424 audio->playingCh4 = 0;
425 GBAudioWriteNR10(audio, 0);
426 GBAudioWriteNR12(audio, 0);
427 GBAudioWriteNR13(audio, 0);
428 GBAudioWriteNR14(audio, 0);
429 GBAudioWriteNR22(audio, 0);
430 GBAudioWriteNR23(audio, 0);
431 GBAudioWriteNR24(audio, 0);
432 GBAudioWriteNR30(audio, 0);
433 GBAudioWriteNR32(audio, 0);
434 GBAudioWriteNR33(audio, 0);
435 GBAudioWriteNR34(audio, 0);
436 GBAudioWriteNR42(audio, 0);
437 GBAudioWriteNR43(audio, 0);
438 GBAudioWriteNR44(audio, 0);
439 GBAudioWriteNR50(audio, 0);
440 GBAudioWriteNR51(audio, 0);
441 if (audio->style != GB_AUDIO_DMG) {
442 GBAudioWriteNR11(audio, 0);
443 GBAudioWriteNR21(audio, 0);
444 GBAudioWriteNR31(audio, 0);
445 GBAudioWriteNR41(audio, 0);
446 }
447
448 if (audio->p) {
449 audio->p->memory.io[REG_NR10] = 0;
450 audio->p->memory.io[REG_NR11] = 0;
451 audio->p->memory.io[REG_NR12] = 0;
452 audio->p->memory.io[REG_NR13] = 0;
453 audio->p->memory.io[REG_NR14] = 0;
454 audio->p->memory.io[REG_NR21] = 0;
455 audio->p->memory.io[REG_NR22] = 0;
456 audio->p->memory.io[REG_NR23] = 0;
457 audio->p->memory.io[REG_NR24] = 0;
458 audio->p->memory.io[REG_NR30] = 0;
459 audio->p->memory.io[REG_NR31] = 0;
460 audio->p->memory.io[REG_NR32] = 0;
461 audio->p->memory.io[REG_NR33] = 0;
462 audio->p->memory.io[REG_NR34] = 0;
463 audio->p->memory.io[REG_NR42] = 0;
464 audio->p->memory.io[REG_NR43] = 0;
465 audio->p->memory.io[REG_NR44] = 0;
466 audio->p->memory.io[REG_NR50] = 0;
467 audio->p->memory.io[REG_NR51] = 0;
468 if (audio->style != GB_AUDIO_DMG) {
469 audio->p->memory.io[REG_NR11] = 0;
470 audio->p->memory.io[REG_NR21] = 0;
471 audio->p->memory.io[REG_NR31] = 0;
472 audio->p->memory.io[REG_NR41] = 0;
473 }
474 }
475 *audio->nr52 &= ~0x000F;
476 } else if (!wasEnable) {
477 audio->skipFrame = false;
478 audio->frame = 7;
479
480 if (audio->p) {
481 unsigned timingFactor = 0x400 >> !audio->p->doubleSpeed;
482 if (audio->p->timer.internalDiv & timingFactor) {
483 audio->skipFrame = true;
484 }
485 }
486 }
487}
488
489void _updateFrame(struct mTiming* timing, void* user, uint32_t cyclesLate) {
490 struct GBAudio* audio = user;
491 GBAudioUpdateFrame(audio, timing);
492 if (audio->style == GB_AUDIO_GBA) {
493 mTimingSchedule(timing, &audio->frameEvent, audio->timingFactor * FRAME_CYCLES - cyclesLate);
494 }
495}
496
497void GBAudioUpdateFrame(struct GBAudio* audio, struct mTiming* timing) {
498 if (!audio->enable) {
499 return;
500 }
501 if (audio->skipFrame) {
502 audio->skipFrame = false;
503 return;
504 }
505 int frame = (audio->frame + 1) & 7;
506 audio->frame = frame;
507
508 switch (frame) {
509 case 2:
510 case 6:
511 if (audio->ch1.sweep.enable) {
512 --audio->ch1.sweep.step;
513 if (audio->ch1.sweep.step == 0) {
514 audio->playingCh1 = _updateSweep(&audio->ch1, false);
515 *audio->nr52 &= ~0x0001;
516 *audio->nr52 |= audio->playingCh1;
517 if (!audio->playingCh1) {
518 mTimingDeschedule(audio->timing, &audio->ch1Event);
519 }
520 }
521 }
522 // Fall through
523 case 0:
524 case 4:
525 if (audio->ch1.control.length && audio->ch1.control.stop) {
526 --audio->ch1.control.length;
527 if (audio->ch1.control.length == 0) {
528 mTimingDeschedule(timing, &audio->ch1Event);
529 audio->playingCh1 = 0;
530 *audio->nr52 &= ~0x0001;
531 }
532 }
533
534 if (audio->ch2.control.length && audio->ch2.control.stop) {
535 --audio->ch2.control.length;
536 if (audio->ch2.control.length == 0) {
537 mTimingDeschedule(timing, &audio->ch2Event);
538 audio->playingCh2 = 0;
539 *audio->nr52 &= ~0x0002;
540 }
541 }
542
543 if (audio->ch3.length && audio->ch3.stop) {
544 --audio->ch3.length;
545 if (audio->ch3.length == 0) {
546 mTimingDeschedule(timing, &audio->ch3Event);
547 audio->playingCh3 = 0;
548 *audio->nr52 &= ~0x0004;
549 }
550 }
551
552 if (audio->ch4.length && audio->ch4.stop) {
553 --audio->ch4.length;
554 if (audio->ch4.length == 0) {
555 mTimingDeschedule(timing, &audio->ch4Event);
556 audio->playingCh4 = 0;
557 *audio->nr52 &= ~0x0008;
558 }
559 }
560 break;
561 case 7:
562 if (audio->playingCh1 && !audio->ch1.envelope.dead) {
563 --audio->ch1.envelope.nextStep;
564 if (audio->ch1.envelope.nextStep == 0) {
565 _updateEnvelope(&audio->ch1.envelope);
566 if (audio->ch1.envelope.dead == 2) {
567 mTimingDeschedule(timing, &audio->ch1Event);
568 }
569 _updateSquareSample(&audio->ch1);
570 }
571 }
572
573 if (audio->playingCh2 && !audio->ch2.envelope.dead) {
574 --audio->ch2.envelope.nextStep;
575 if (audio->ch2.envelope.nextStep == 0) {
576 _updateEnvelope(&audio->ch2.envelope);
577 if (audio->ch2.envelope.dead == 2) {
578 mTimingDeschedule(timing, &audio->ch2Event);
579 }
580 _updateSquareSample(&audio->ch2);
581 }
582 }
583
584 if (audio->playingCh4 && !audio->ch4.envelope.dead) {
585 --audio->ch4.envelope.nextStep;
586 if (audio->ch4.envelope.nextStep == 0) {
587 int8_t sample = audio->ch4.sample > 0;
588 audio->ch4.samples -= audio->ch4.sample;
589 _updateEnvelope(&audio->ch4.envelope);
590 if (audio->ch4.envelope.dead == 2) {
591 mTimingDeschedule(timing, &audio->ch4Event);
592 }
593 audio->ch4.sample = sample * audio->ch4.envelope.currentVolume;
594 audio->ch4.samples += audio->ch4.sample;
595 }
596 }
597 break;
598 }
599}
600
601void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right) {
602 int dcOffset = audio->style == GB_AUDIO_GBA ? 0 : -0x8;
603 int sampleLeft = dcOffset;
604 int sampleRight = dcOffset;
605
606 if (!audio->forceDisableCh[0]) {
607 if (audio->ch1Left) {
608 sampleLeft += audio->ch1.sample;
609 }
610
611 if (audio->ch1Right) {
612 sampleRight += audio->ch1.sample;
613 }
614 }
615
616 if (!audio->forceDisableCh[1]) {
617 if (audio->ch2Left) {
618 sampleLeft += audio->ch2.sample;
619 }
620
621 if (audio->ch2Right) {
622 sampleRight += audio->ch2.sample;
623 }
624 }
625
626 if (!audio->forceDisableCh[2]) {
627 if (audio->ch3Left) {
628 sampleLeft += audio->ch3.sample;
629 }
630
631 if (audio->ch3Right) {
632 sampleRight += audio->ch3.sample;
633 }
634 }
635
636 sampleLeft <<= 3;
637 sampleRight <<= 3;
638
639 if (!audio->forceDisableCh[3]) {
640 int16_t sample = audio->style == GB_AUDIO_GBA ? (audio->ch4.sample << 3) : _coalesceNoiseChannel(&audio->ch4);
641 if (audio->ch4Left) {
642 sampleLeft += sample;
643 }
644
645 if (audio->ch4Right) {
646 sampleRight += sample;
647 }
648 }
649
650 *left = sampleLeft * (1 + audio->volumeLeft);
651 *right = sampleRight * (1 + audio->volumeRight);
652}
653
654static void _sample(struct mTiming* timing, void* user, uint32_t cyclesLate) {
655 struct GBAudio* audio = user;
656 int16_t sampleLeft = 0;
657 int16_t sampleRight = 0;
658 GBAudioSamplePSG(audio, &sampleLeft, &sampleRight);
659 sampleLeft = (sampleLeft * audio->masterVolume * 6) >> 7;
660 sampleRight = (sampleRight * audio->masterVolume * 6) >> 7;
661
662 mCoreSyncLockAudio(audio->p->sync);
663 unsigned produced;
664
665 int16_t degradedLeft = sampleLeft - (audio->capLeft >> 16);
666 int16_t degradedRight = sampleRight - (audio->capRight >> 16);
667 audio->capLeft = (sampleLeft << 16) - degradedLeft * 65184;
668 audio->capRight = (sampleRight << 16) - degradedRight * 65184;
669 sampleLeft = degradedLeft;
670 sampleRight = degradedRight;
671
672 if ((size_t) blip_samples_avail(audio->left) < audio->samples) {
673 blip_add_delta(audio->left, audio->clock, sampleLeft - audio->lastLeft);
674 blip_add_delta(audio->right, audio->clock, sampleRight - audio->lastRight);
675 audio->lastLeft = sampleLeft;
676 audio->lastRight = sampleRight;
677 audio->clock += audio->sampleInterval;
678 if (audio->clock >= CLOCKS_PER_BLIP_FRAME) {
679 blip_end_frame(audio->left, CLOCKS_PER_BLIP_FRAME);
680 blip_end_frame(audio->right, CLOCKS_PER_BLIP_FRAME);
681 audio->clock -= CLOCKS_PER_BLIP_FRAME;
682 }
683 }
684 produced = blip_samples_avail(audio->left);
685 if (audio->p->stream && audio->p->stream->postAudioFrame) {
686 audio->p->stream->postAudioFrame(audio->p->stream, sampleLeft, sampleRight);
687 }
688 bool wait = produced >= audio->samples;
689 if (!mCoreSyncProduceAudio(audio->p->sync, audio->left, audio->samples)) {
690 // Interrupted
691 audio->p->earlyExit = true;
692 }
693
694 if (wait && audio->p->stream && audio->p->stream->postAudioBuffer) {
695 audio->p->stream->postAudioBuffer(audio->p->stream, audio->left, audio->right);
696 }
697 mTimingSchedule(timing, &audio->sampleEvent, audio->sampleInterval * audio->timingFactor - cyclesLate);
698}
699
700bool _resetEnvelope(struct GBAudioEnvelope* envelope) {
701 envelope->currentVolume = envelope->initialVolume;
702 _updateEnvelopeDead(envelope);
703 if (!envelope->dead) {
704 envelope->nextStep = envelope->stepTime;
705 }
706 return envelope->initialVolume || envelope->direction;
707}
708
709void _resetSweep(struct GBAudioSweep* sweep) {
710 sweep->step = sweep->time;
711 sweep->enable = (sweep->step != 8) || sweep->shift;
712 sweep->occurred = false;
713}
714
715bool _writeSweep(struct GBAudioSweep* sweep, uint8_t value) {
716 sweep->shift = GBAudioRegisterSquareSweepGetShift(value);
717 bool oldDirection = sweep->direction;
718 sweep->direction = GBAudioRegisterSquareSweepGetDirection(value);
719 bool on = true;
720 if (sweep->occurred && oldDirection && !sweep->direction) {
721 on = false;
722 }
723 sweep->occurred = false;
724 sweep->time = GBAudioRegisterSquareSweepGetTime(value);
725 if (!sweep->time) {
726 sweep->time = 8;
727 }
728 return on;
729}
730
731void _writeDuty(struct GBAudioEnvelope* envelope, uint8_t value) {
732 envelope->length = GBAudioRegisterDutyGetLength(value);
733 envelope->duty = GBAudioRegisterDutyGetDuty(value);
734}
735
736bool _writeEnvelope(struct GBAudioEnvelope* envelope, uint8_t value, enum GBAudioStyle style) {
737 envelope->stepTime = GBAudioRegisterSweepGetStepTime(value);
738 envelope->direction = GBAudioRegisterSweepGetDirection(value);
739 envelope->initialVolume = GBAudioRegisterSweepGetInitialVolume(value);
740 if (style == GB_AUDIO_DMG && !envelope->stepTime) {
741 // TODO: Improve "zombie" mode
742 ++envelope->currentVolume;
743 envelope->currentVolume &= 0xF;
744 }
745 _updateEnvelopeDead(envelope);
746 return (envelope->initialVolume || envelope->direction) && envelope->dead != 2;
747}
748
749static void _updateSquareSample(struct GBAudioSquareChannel* ch) {
750 ch->sample = ch->control.hi * ch->envelope.currentVolume;
751}
752
753static int32_t _updateSquareChannel(struct GBAudioSquareChannel* ch) {
754 ch->control.hi = !ch->control.hi;
755 _updateSquareSample(ch);
756 int period = 4 * (2048 - ch->control.frequency);
757 switch (ch->envelope.duty) {
758 case 0:
759 return ch->control.hi ? period : period * 7;
760 case 1:
761 return ch->control.hi ? period * 2 : period * 6;
762 case 2:
763 return period * 4;
764 case 3:
765 return ch->control.hi ? period * 6 : period * 2;
766 default:
767 // This should never be hit
768 return period * 4;
769 }
770}
771
772static int16_t _coalesceNoiseChannel(struct GBAudioNoiseChannel* ch) {
773 if (!ch->nSamples) {
774 return ch->sample << 3;
775 }
776 // TODO keep track of timing
777 int16_t sample = (ch->samples << 3) / ch->nSamples;
778 ch->nSamples = 0;
779 ch->samples = 0;
780 return sample;
781}
782
783static void _updateEnvelope(struct GBAudioEnvelope* envelope) {
784 if (envelope->direction) {
785 ++envelope->currentVolume;
786 } else {
787 --envelope->currentVolume;
788 }
789 if (envelope->currentVolume >= 15) {
790 envelope->currentVolume = 15;
791 envelope->dead = 1;
792 } else if (envelope->currentVolume <= 0) {
793 envelope->currentVolume = 0;
794 envelope->dead = 2;
795 } else {
796 envelope->nextStep = envelope->stepTime;
797 }
798}
799
800static void _updateEnvelopeDead(struct GBAudioEnvelope* envelope) {
801 if (!envelope->stepTime) {
802 envelope->dead = envelope->currentVolume ? 1 : 2;
803 } else if (!envelope->direction && !envelope->currentVolume) {
804 envelope->dead = 2;
805 } else if (envelope->direction && envelope->currentVolume == 0xF) {
806 envelope->dead = 1;
807 } else {
808 envelope->dead = 0;
809 }
810}
811
812static bool _updateSweep(struct GBAudioSquareChannel* ch, bool initial) {
813 if (initial || ch->sweep.time != 8) {
814 int frequency = ch->sweep.realFrequency;
815 if (ch->sweep.direction) {
816 frequency -= frequency >> ch->sweep.shift;
817 if (!initial && frequency >= 0) {
818 ch->control.frequency = frequency;
819 ch->sweep.realFrequency = frequency;
820 }
821 } else {
822 frequency += frequency >> ch->sweep.shift;
823 if (frequency < 2048) {
824 if (!initial && ch->sweep.shift) {
825 ch->control.frequency = frequency;
826 ch->sweep.realFrequency = frequency;
827 if (!_updateSweep(ch, true)) {
828 return false;
829 }
830 }
831 } else {
832 return false;
833 }
834 }
835 ch->sweep.occurred = true;
836 }
837 ch->sweep.step = ch->sweep.time;
838 return true;
839}
840
841static void _updateChannel1(struct mTiming* timing, void* user, uint32_t cyclesLate) {
842 struct GBAudio* audio = user;
843 struct GBAudioSquareChannel* ch = &audio->ch1;
844 int cycles = _updateSquareChannel(ch);
845 mTimingSchedule(timing, &audio->ch1Event, audio->timingFactor * cycles - cyclesLate);
846}
847
848static void _updateChannel2(struct mTiming* timing, void* user, uint32_t cyclesLate) {
849 struct GBAudio* audio = user;
850 struct GBAudioSquareChannel* ch = &audio->ch2;
851 int cycles = _updateSquareChannel(ch);
852 mTimingSchedule(timing, &audio->ch2Event, audio->timingFactor * cycles - cyclesLate);
853}
854
855static void _updateChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
856 struct GBAudio* audio = user;
857 struct GBAudioWaveChannel* ch = &audio->ch3;
858 int i;
859 int volume;
860 switch (ch->volume) {
861 case 0:
862 volume = 4;
863 break;
864 case 1:
865 volume = 0;
866 break;
867 case 2:
868 volume = 1;
869 break;
870 default:
871 case 3:
872 volume = 2;
873 break;
874 }
875 int start;
876 int end;
877 switch (audio->style) {
878 case GB_AUDIO_DMG:
879 default:
880 ++ch->window;
881 ch->window &= 0x1F;
882 ch->sample = ch->wavedata8[ch->window >> 1];
883 if (!(ch->window & 1)) {
884 ch->sample >>= 4;
885 }
886 ch->sample &= 0xF;
887 break;
888 case GB_AUDIO_GBA:
889 if (ch->size) {
890 start = 7;
891 end = 0;
892 } else if (ch->bank) {
893 start = 7;
894 end = 4;
895 } else {
896 start = 3;
897 end = 0;
898 }
899 uint32_t bitsCarry = ch->wavedata32[end] & 0x000000F0;
900 uint32_t bits;
901 for (i = start; i >= end; --i) {
902 bits = ch->wavedata32[i] & 0x000000F0;
903 ch->wavedata32[i] = ((ch->wavedata32[i] & 0x0F0F0F0F) << 4) | ((ch->wavedata32[i] & 0xF0F0F000) >> 12);
904 ch->wavedata32[i] |= bitsCarry << 20;
905 bitsCarry = bits;
906 }
907 ch->sample = bitsCarry >> 4;
908 break;
909 }
910 if (ch->volume > 3) {
911 ch->sample += ch->sample << 1;
912 }
913 ch->sample >>= volume;
914 audio->ch3.readable = true;
915 if (audio->style == GB_AUDIO_DMG) {
916 mTimingDeschedule(audio->timing, &audio->ch3Fade);
917 mTimingSchedule(timing, &audio->ch3Fade, 2 - cyclesLate);
918 }
919 int cycles = 2 * (2048 - ch->rate);
920 mTimingSchedule(timing, &audio->ch3Event, audio->timingFactor * cycles - cyclesLate);
921}
922static void _fadeChannel3(struct mTiming* timing, void* user, uint32_t cyclesLate) {
923 UNUSED(timing);
924 UNUSED(cyclesLate);
925 struct GBAudio* audio = user;
926 audio->ch3.readable = false;
927}
928
929static void _updateChannel4(struct mTiming* timing, void* user, uint32_t cyclesLate) {
930 struct GBAudio* audio = user;
931 struct GBAudioNoiseChannel* ch = &audio->ch4;
932
933 int32_t cycles = ch->ratio ? 2 * ch->ratio : 1;
934 cycles <<= ch->frequency;
935 cycles *= 8 * audio->timingFactor;
936
937 uint32_t last = 0;
938 uint32_t now = cycles;
939 uint32_t next = cycles - cyclesLate;
940
941 if (audio->style == GB_AUDIO_GBA) {
942 last = ch->lastEvent;
943 now = mTimingCurrentTime(timing) - cyclesLate;
944 ch->lastEvent = now;
945 now -= last;
946 last = 0;
947 if (audio->sampleInterval > next) {
948 // TODO: Make batching work when descheduled
949 next = audio->sampleInterval;
950 }
951 }
952
953 for (; last < now; last += cycles) {
954 int lsb = ch->lfsr & 1;
955 ch->sample = lsb * ch->envelope.currentVolume;
956 ++ch->nSamples;
957 ch->samples += ch->sample;
958 ch->lfsr >>= 1;
959 ch->lfsr ^= (lsb * 0x60) << (ch->power ? 0 : 8);
960 }
961
962 mTimingSchedule(timing, &audio->ch4Event, next);
963}
964
965void GBAudioPSGSerialize(const struct GBAudio* audio, struct GBSerializedPSGState* state, uint32_t* flagsOut) {
966 uint32_t flags = 0;
967 uint32_t ch1Flags = 0;
968 uint32_t ch2Flags = 0;
969 uint32_t ch4Flags = 0;
970
971 flags = GBSerializedAudioFlagsSetFrame(flags, audio->frame);
972 flags = GBSerializedAudioFlagsSetSkipFrame(flags, audio->skipFrame);
973 STORE_32LE(audio->frameEvent.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextFrame);
974
975 flags = GBSerializedAudioFlagsSetCh1Volume(flags, audio->ch1.envelope.currentVolume);
976 flags = GBSerializedAudioFlagsSetCh1Dead(flags, audio->ch1.envelope.dead);
977 flags = GBSerializedAudioFlagsSetCh1Hi(flags, audio->ch1.control.hi);
978 flags = GBSerializedAudioFlagsSetCh1SweepEnabled(flags, audio->ch1.sweep.enable);
979 flags = GBSerializedAudioFlagsSetCh1SweepOccurred(flags, audio->ch1.sweep.occurred);
980 ch1Flags = GBSerializedAudioEnvelopeSetLength(ch1Flags, audio->ch1.control.length);
981 ch1Flags = GBSerializedAudioEnvelopeSetNextStep(ch1Flags, audio->ch1.envelope.nextStep);
982 ch1Flags = GBSerializedAudioEnvelopeSetFrequency(ch1Flags, audio->ch1.sweep.realFrequency);
983 STORE_32LE(ch1Flags, 0, &state->ch1.envelope);
984 STORE_32LE(audio->ch1Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextEvent);
985
986 flags = GBSerializedAudioFlagsSetCh2Volume(flags, audio->ch2.envelope.currentVolume);
987 flags = GBSerializedAudioFlagsSetCh2Dead(flags, audio->ch2.envelope.dead);
988 flags = GBSerializedAudioFlagsSetCh2Hi(flags, audio->ch2.control.hi);
989 ch2Flags = GBSerializedAudioEnvelopeSetLength(ch2Flags, audio->ch2.control.length);
990 ch2Flags = GBSerializedAudioEnvelopeSetNextStep(ch2Flags, audio->ch2.envelope.nextStep);
991 STORE_32LE(ch2Flags, 0, &state->ch2.envelope);
992 STORE_32LE(audio->ch2Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch2.nextEvent);
993
994 flags = GBSerializedAudioFlagsSetCh3Readable(flags, audio->ch3.readable);
995 memcpy(state->ch3.wavebanks, audio->ch3.wavedata32, sizeof(state->ch3.wavebanks));
996 STORE_16LE(audio->ch3.length, 0, &state->ch3.length);
997 STORE_32LE(audio->ch3Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch3.nextEvent);
998 STORE_32LE(audio->ch3Fade.when - mTimingCurrentTime(audio->timing), 0, &state->ch1.nextCh3Fade);
999
1000 flags = GBSerializedAudioFlagsSetCh4Volume(flags, audio->ch4.envelope.currentVolume);
1001 flags = GBSerializedAudioFlagsSetCh4Dead(flags, audio->ch4.envelope.dead);
1002 STORE_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
1003 ch4Flags = GBSerializedAudioEnvelopeSetLength(ch4Flags, audio->ch4.length);
1004 ch4Flags = GBSerializedAudioEnvelopeSetNextStep(ch4Flags, audio->ch4.envelope.nextStep);
1005 STORE_32LE(ch4Flags, 0, &state->ch4.envelope);
1006 STORE_32LE(audio->ch4.lastEvent, 0, &state->ch4.lastEvent);
1007 STORE_32LE(audio->ch4Event.when - mTimingCurrentTime(audio->timing), 0, &state->ch4.nextEvent);
1008
1009 STORE_32LE(flags, 0, flagsOut);
1010}
1011
1012void GBAudioPSGDeserialize(struct GBAudio* audio, const struct GBSerializedPSGState* state, const uint32_t* flagsIn) {
1013 uint32_t flags;
1014 uint32_t ch1Flags = 0;
1015 uint32_t ch2Flags = 0;
1016 uint32_t ch4Flags = 0;
1017 uint32_t when;
1018
1019 audio->playingCh1 = !!(*audio->nr52 & 0x0001);
1020 audio->playingCh2 = !!(*audio->nr52 & 0x0002);
1021 audio->playingCh3 = !!(*audio->nr52 & 0x0004);
1022 audio->playingCh4 = !!(*audio->nr52 & 0x0008);
1023 audio->enable = GBAudioEnableGetEnable(*audio->nr52);
1024
1025 if (audio->style == GB_AUDIO_GBA) {
1026 LOAD_32LE(when, 0, &state->ch1.nextFrame);
1027 mTimingSchedule(audio->timing, &audio->frameEvent, when);
1028 }
1029
1030 LOAD_32LE(flags, 0, flagsIn);
1031 audio->frame = GBSerializedAudioFlagsGetFrame(flags);
1032 audio->skipFrame = GBSerializedAudioFlagsGetSkipFrame(flags);
1033
1034 LOAD_32LE(ch1Flags, 0, &state->ch1.envelope);
1035 audio->ch1.envelope.currentVolume = GBSerializedAudioFlagsGetCh1Volume(flags);
1036 audio->ch1.envelope.dead = GBSerializedAudioFlagsGetCh1Dead(flags);
1037 audio->ch1.control.hi = GBSerializedAudioFlagsGetCh1Hi(flags);
1038 audio->ch1.sweep.enable = GBSerializedAudioFlagsGetCh1SweepEnabled(flags);
1039 audio->ch1.sweep.occurred = GBSerializedAudioFlagsGetCh1SweepOccurred(flags);
1040 audio->ch1.control.length = GBSerializedAudioEnvelopeGetLength(ch1Flags);
1041 audio->ch1.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch1Flags);
1042 audio->ch1.sweep.realFrequency = GBSerializedAudioEnvelopeGetFrequency(ch1Flags);
1043 LOAD_32LE(when, 0, &state->ch1.nextEvent);
1044 if (audio->ch1.envelope.dead < 2 && audio->playingCh1) {
1045 mTimingSchedule(audio->timing, &audio->ch1Event, when);
1046 }
1047
1048 LOAD_32LE(ch2Flags, 0, &state->ch2.envelope);
1049 audio->ch2.envelope.currentVolume = GBSerializedAudioFlagsGetCh2Volume(flags);
1050 audio->ch2.envelope.dead = GBSerializedAudioFlagsGetCh2Dead(flags);
1051 audio->ch2.control.hi = GBSerializedAudioFlagsGetCh2Hi(flags);
1052 audio->ch2.control.length = GBSerializedAudioEnvelopeGetLength(ch2Flags);
1053 audio->ch2.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch2Flags);
1054 LOAD_32LE(when, 0, &state->ch2.nextEvent);
1055 if (audio->ch2.envelope.dead < 2 && audio->playingCh2) {
1056 mTimingSchedule(audio->timing, &audio->ch2Event, when);
1057 }
1058
1059 audio->ch3.readable = GBSerializedAudioFlagsGetCh3Readable(flags);
1060 // TODO: Big endian?
1061 memcpy(audio->ch3.wavedata32, state->ch3.wavebanks, sizeof(audio->ch3.wavedata32));
1062 LOAD_16LE(audio->ch3.length, 0, &state->ch3.length);
1063 LOAD_32LE(when, 0, &state->ch3.nextEvent);
1064 if (audio->playingCh3) {
1065 mTimingSchedule(audio->timing, &audio->ch3Event, when);
1066 }
1067 LOAD_32LE(when, 0, &state->ch1.nextCh3Fade);
1068 if (audio->ch3.readable && audio->style == GB_AUDIO_DMG) {
1069 mTimingSchedule(audio->timing, &audio->ch3Fade, when);
1070 }
1071
1072 LOAD_32LE(ch4Flags, 0, &state->ch4.envelope);
1073 audio->ch4.envelope.currentVolume = GBSerializedAudioFlagsGetCh4Volume(flags);
1074 audio->ch4.envelope.dead = GBSerializedAudioFlagsGetCh4Dead(flags);
1075 audio->ch4.length = GBSerializedAudioEnvelopeGetLength(ch4Flags);
1076 audio->ch4.envelope.nextStep = GBSerializedAudioEnvelopeGetNextStep(ch4Flags);
1077 LOAD_32LE(audio->ch4.lfsr, 0, &state->ch4.lfsr);
1078 LOAD_32LE(audio->ch4.lastEvent, 0, &state->ch4.lastEvent);
1079 LOAD_32LE(when, 0, &state->ch4.nextEvent);
1080 if (audio->ch4.envelope.dead < 2 && audio->playingCh4) {
1081 if (when - audio->ch4.lastEvent > (uint32_t) audio->sampleInterval) {
1082 // Back-compat: fake this value
1083 audio->ch4.lastEvent = when - audio->sampleInterval;
1084 }
1085 mTimingSchedule(audio->timing, &audio->ch4Event, when);
1086 }
1087}
1088
1089void GBAudioSerialize(const struct GBAudio* audio, struct GBSerializedState* state) {
1090 GBAudioPSGSerialize(audio, &state->audio.psg, &state->audio.flags);
1091 STORE_32LE(audio->capLeft, 0, &state->audio.capLeft);
1092 STORE_32LE(audio->capRight, 0, &state->audio.capRight);
1093 STORE_32LE(audio->sampleEvent.when - mTimingCurrentTime(audio->timing), 0, &state->audio.nextSample);
1094}
1095
1096void GBAudioDeserialize(struct GBAudio* audio, const struct GBSerializedState* state) {
1097 GBAudioPSGDeserialize(audio, &state->audio.psg, &state->audio.flags);
1098 LOAD_32LE(audio->capLeft, 0, &state->audio.capLeft);
1099 LOAD_32LE(audio->capRight, 0, &state->audio.capRight);
1100 uint32_t when;
1101 LOAD_32LE(when, 0, &state->audio.nextSample);
1102 mTimingSchedule(audio->timing, &audio->sampleEvent, when);
1103}