src/gba/gba-audio.c (view raw)
1#include "gba-audio.h"
2
3#include "gba.h"
4#include "gba-io.h"
5#include "gba-serialize.h"
6#include "gba-thread.h"
7#include "gba-video.h"
8
9const unsigned GBA_AUDIO_SAMPLES = 2048;
10const unsigned GBA_AUDIO_FIFO_SIZE = 8 * sizeof(int32_t);
11#define SWEEP_CYCLES (GBA_ARM7TDMI_FREQUENCY / 128)
12
13static bool _writeEnvelope(struct GBAAudioEnvelope* envelope, uint16_t value);
14static int32_t _updateSquareChannel(struct GBAAudioSquareControl* envelope, int duty);
15static void _updateEnvelope(struct GBAAudioEnvelope* envelope);
16static bool _updateSweep(struct GBAAudioChannel1* ch);
17static int32_t _updateChannel1(struct GBAAudioChannel1* ch);
18static int32_t _updateChannel2(struct GBAAudioChannel2* ch);
19static int32_t _updateChannel3(struct GBAAudioChannel3* ch);
20static int32_t _updateChannel4(struct GBAAudioChannel4* ch);
21static int _applyBias(struct GBAAudio* audio, int sample);
22static void _sample(struct GBAAudio* audio);
23
24void GBAAudioInit(struct GBAAudio* audio, size_t samples) {
25 CircleBufferInit(&audio->left, samples * sizeof(int32_t));
26 CircleBufferInit(&audio->right, samples * sizeof(int32_t));
27 CircleBufferInit(&audio->chA.fifo, GBA_AUDIO_FIFO_SIZE);
28 CircleBufferInit(&audio->chB.fifo, GBA_AUDIO_FIFO_SIZE);
29}
30
31void GBAAudioReset(struct GBAAudio* audio) {
32 audio->nextEvent = 0;
33 audio->nextCh1 = 0;
34 audio->nextCh2 = 0;
35 audio->nextCh3 = 0;
36 audio->nextCh4 = 0;
37 audio->ch1 = (struct GBAAudioChannel1) { .envelope = { .nextStep = INT_MAX }, .nextSweep = INT_MAX };
38 audio->ch2 = (struct GBAAudioChannel2) { .envelope = { .nextStep = INT_MAX } };
39 audio->ch3 = (struct GBAAudioChannel3) { .bank = { .bank = 0 } };
40 audio->ch4 = (struct GBAAudioChannel4) { .envelope = { .nextStep = INT_MAX } };
41 audio->chA.dmaSource = 0;
42 audio->chB.dmaSource = 0;
43 audio->eventDiff = 0;
44 audio->nextSample = 0;
45 audio->sampleRate = 0x8000;
46 audio->soundbias = 0x200;
47 audio->volumeRight = 0;
48 audio->volumeLeft = 0;
49 audio->ch1Right = false;
50 audio->ch2Right = false;
51 audio->ch3Right = false;
52 audio->ch4Right = false;
53 audio->ch1Left = false;
54 audio->ch2Left = false;
55 audio->ch3Left = false;
56 audio->ch4Left = false;
57 audio->volume = 0;
58 audio->volumeChA = false;
59 audio->volumeChB = false;
60 audio->chARight = false;
61 audio->chALeft = false;
62 audio->chATimer = false;
63 audio->chBRight = false;
64 audio->chBLeft = false;
65 audio->chBTimer = false;
66 audio->playingCh1 = false;
67 audio->playingCh2 = false;
68 audio->playingCh3 = false;
69 audio->playingCh4 = false;
70 audio->enable = false;
71 audio->sampleInterval = GBA_ARM7TDMI_FREQUENCY / audio->sampleRate;
72
73 CircleBufferClear(&audio->left);
74 CircleBufferClear(&audio->right);
75 CircleBufferClear(&audio->chA.fifo);
76 CircleBufferClear(&audio->chB.fifo);
77}
78
79void GBAAudioDeinit(struct GBAAudio* audio) {
80 CircleBufferDeinit(&audio->left);
81 CircleBufferDeinit(&audio->right);
82 CircleBufferDeinit(&audio->chA.fifo);
83 CircleBufferDeinit(&audio->chB.fifo);
84}
85
86void GBAAudioResizeBuffer(struct GBAAudio* audio, size_t samples) {
87 if (samples > GBA_AUDIO_SAMPLES) {
88 return;
89 }
90
91 GBASyncLockAudio(audio->p->sync);
92 int32_t buffer[GBA_AUDIO_SAMPLES];
93 int32_t dummy;
94 size_t read;
95 size_t i;
96
97 read = CircleBufferDump(&audio->left, buffer, sizeof(buffer));
98 CircleBufferDeinit(&audio->left);
99 CircleBufferInit(&audio->left, samples * sizeof(int32_t));
100 for (i = 0; i * sizeof(int32_t) < read; ++i) {
101 if (!CircleBufferWrite32(&audio->left, buffer[i])) {
102 CircleBufferRead32(&audio->left, &dummy);
103 CircleBufferWrite32(&audio->left, buffer[i]);
104 }
105 }
106
107 read = CircleBufferDump(&audio->right, buffer, sizeof(buffer));
108 CircleBufferDeinit(&audio->right);
109 CircleBufferInit(&audio->right, samples * sizeof(int32_t));
110 for (i = 0; i * sizeof(int32_t) < read; ++i) {
111 if (!CircleBufferWrite32(&audio->right, buffer[i])) {
112 CircleBufferRead32(&audio->right, &dummy);
113 CircleBufferWrite32(&audio->right, buffer[i]);
114 }
115 }
116
117 GBASyncUnlockAudio(audio->p->sync);
118}
119
120int32_t GBAAudioProcessEvents(struct GBAAudio* audio, int32_t cycles) {
121 audio->nextEvent -= cycles;
122 audio->eventDiff += cycles;
123 if (audio->nextEvent <= 0) {
124 audio->nextEvent = INT_MAX;
125 if (audio->enable) {
126 if (audio->playingCh1 && !audio->ch1.envelope.dead) {
127 audio->nextCh1 -= audio->eventDiff;
128 if (audio->ch1.envelope.nextStep != INT_MAX) {
129 audio->ch1.envelope.nextStep -= audio->eventDiff;
130 if (audio->ch1.envelope.nextStep <= 0) {
131 int8_t sample = audio->ch1.control.hi * 0x10 - 0x8;
132 _updateEnvelope(&audio->ch1.envelope);
133 if (audio->ch1.envelope.nextStep < audio->nextEvent) {
134 audio->nextEvent = audio->ch1.envelope.nextStep;
135 }
136 audio->ch1.sample = sample * audio->ch1.envelope.currentVolume;
137 }
138 }
139
140 if (audio->ch1.nextSweep != INT_MAX) {
141 audio->ch1.nextSweep -= audio->eventDiff;
142 if (audio->ch1.nextSweep <= 0) {
143 audio->playingCh1 = _updateSweep(&audio->ch1);
144 if (audio->ch1.nextSweep < audio->nextEvent) {
145 audio->nextEvent = audio->ch1.nextSweep;
146 }
147 }
148 }
149
150 if (audio->nextCh1 <= 0) {
151 audio->nextCh1 += _updateChannel1(&audio->ch1);
152 if (audio->nextCh1 < audio->nextEvent) {
153 audio->nextEvent = audio->nextCh1;
154 }
155 }
156
157 if (audio->ch1.control.stop) {
158 audio->ch1.control.endTime -= audio->eventDiff;
159 if (audio->ch1.control.endTime <= 0) {
160 audio->playingCh1 = 0;
161 }
162 }
163 }
164
165 if (audio->playingCh2 && !audio->ch2.envelope.dead) {
166 audio->nextCh2 -= audio->eventDiff;
167 if (audio->ch2.envelope.nextStep != INT_MAX) {
168 audio->ch2.envelope.nextStep -= audio->eventDiff;
169 if (audio->ch2.envelope.nextStep <= 0) {
170 int8_t sample = audio->ch2.control.hi * 0x10 - 0x8;
171 _updateEnvelope(&audio->ch2.envelope);
172 if (audio->ch2.envelope.nextStep < audio->nextEvent) {
173 audio->nextEvent = audio->ch2.envelope.nextStep;
174 }
175 audio->ch2.sample = sample * audio->ch2.envelope.currentVolume;
176 }
177 }
178
179 if (audio->nextCh2 <= 0) {
180 audio->nextCh2 += _updateChannel2(&audio->ch2);
181 if (audio->nextCh2 < audio->nextEvent) {
182 audio->nextEvent = audio->nextCh2;
183 }
184 }
185
186 if (audio->ch2.control.stop) {
187 audio->ch2.control.endTime -= audio->eventDiff;
188 if (audio->ch2.control.endTime <= 0) {
189 audio->playingCh2 = 0;
190 }
191 }
192 }
193
194 if (audio->playingCh3) {
195 audio->nextCh3 -= audio->eventDiff;
196 if (audio->nextCh3 <= 0) {
197 audio->nextCh3 += _updateChannel3(&audio->ch3);
198 if (audio->nextCh3 < audio->nextEvent) {
199 audio->nextEvent = audio->nextCh3;
200 }
201 }
202
203 if (audio->ch3.control.stop) {
204 audio->ch3.control.endTime -= audio->eventDiff;
205 if (audio->ch3.control.endTime <= 0) {
206 audio->playingCh3 = 0;
207 }
208 }
209 }
210
211 if (audio->playingCh4 && !audio->ch4.envelope.dead) {
212 audio->nextCh4 -= audio->eventDiff;
213 if (audio->ch4.envelope.nextStep != INT_MAX) {
214 audio->ch4.envelope.nextStep -= audio->eventDiff;
215 if (audio->ch4.envelope.nextStep <= 0) {
216 int8_t sample = (audio->ch4.sample >> 31) * 0x8;
217 _updateEnvelope(&audio->ch4.envelope);
218 if (audio->ch4.envelope.nextStep < audio->nextEvent) {
219 audio->nextEvent = audio->ch4.envelope.nextStep;
220 }
221 audio->ch4.sample = sample * audio->ch4.envelope.currentVolume;
222 }
223 }
224
225 if (audio->nextCh4 <= 0) {
226 audio->nextCh4 += _updateChannel4(&audio->ch4);
227 if (audio->nextCh4 < audio->nextEvent) {
228 audio->nextEvent = audio->nextCh4;
229 }
230 }
231
232 if (audio->ch4.control.stop) {
233 audio->ch4.control.endTime -= audio->eventDiff;
234 if (audio->ch4.control.endTime <= 0) {
235 audio->playingCh4 = 0;
236 }
237 }
238 }
239 }
240
241 audio->nextSample -= audio->eventDiff;
242 if (audio->nextSample <= 0) {
243 _sample(audio);
244 audio->nextSample += audio->sampleInterval;
245 }
246
247 if (audio->nextSample < audio->nextEvent) {
248 audio->nextEvent = audio->nextSample;
249 }
250 audio->eventDiff = 0;
251 }
252 return audio->nextEvent;
253}
254
255void GBAAudioScheduleFifoDma(struct GBAAudio* audio, int number, struct GBADMA* info) {
256 switch (info->dest) {
257 case BASE_IO | REG_FIFO_A_LO:
258 audio->chA.dmaSource = number;
259 break;
260 case BASE_IO | REG_FIFO_B_LO:
261 audio->chB.dmaSource = number;
262 break;
263 default:
264 GBALog(audio->p, GBA_LOG_GAME_ERROR, "Invalid FIFO destination: 0x%08X", info->dest);
265 return;
266 }
267 info->reg = GBADMARegisterSetDestControl(info->reg, DMA_FIXED);
268}
269
270void GBAAudioWriteSOUND1CNT_LO(struct GBAAudio* audio, uint16_t value) {
271 audio->ch1.sweep.shift = GBAAudioRegisterSquareSweepGetShift(value);
272 audio->ch1.sweep.direction = GBAAudioRegisterSquareSweepGetDirection(value);
273 audio->ch1.sweep.time = GBAAudioRegisterSquareSweepGetTime(value);
274 if (audio->ch1.sweep.time) {
275 audio->ch1.nextSweep = audio->ch1.sweep.time * SWEEP_CYCLES;
276 } else {
277 audio->ch1.nextSweep = INT_MAX;
278 }
279}
280
281void GBAAudioWriteSOUND1CNT_HI(struct GBAAudio* audio, uint16_t value) {
282 if (!_writeEnvelope(&audio->ch1.envelope, value)) {
283 audio->ch1.sample = 0;
284 }
285}
286
287void GBAAudioWriteSOUND1CNT_X(struct GBAAudio* audio, uint16_t value) {
288 audio->ch1.control.frequency = GBAAudioRegisterControlGetFrequency(value);
289 audio->ch1.control.stop = GBAAudioRegisterControlGetStop(value);
290 audio->ch1.control.endTime = (GBA_ARM7TDMI_FREQUENCY * (64 - audio->ch1.envelope.length)) >> 8;
291 if (GBAAudioRegisterControlIsRestart(value)) {
292 if (audio->ch1.sweep.time) {
293 audio->ch1.nextSweep = audio->ch1.sweep.time * SWEEP_CYCLES;
294 } else {
295 audio->ch1.nextSweep = INT_MAX;
296 }
297 if (!audio->playingCh1) {
298 audio->nextCh1 = 0;
299 }
300 audio->playingCh1 = 1;
301 if (audio->ch1.envelope.stepTime) {
302 audio->ch1.envelope.nextStep = 0;
303 } else {
304 audio->ch1.envelope.nextStep = INT_MAX;
305 }
306 audio->ch1.envelope.currentVolume = audio->ch1.envelope.initialVolume;
307 if (audio->ch1.envelope.stepTime) {
308 audio->ch1.envelope.nextStep = 0;
309 } else {
310 audio->ch1.envelope.nextStep = INT_MAX;
311 }
312 }
313}
314
315void GBAAudioWriteSOUND2CNT_LO(struct GBAAudio* audio, uint16_t value) {
316 if (!_writeEnvelope(&audio->ch2.envelope, value)) {
317 audio->ch2.sample = 0;
318 }
319}
320
321void GBAAudioWriteSOUND2CNT_HI(struct GBAAudio* audio, uint16_t value) {
322 audio->ch2.control.frequency = GBAAudioRegisterControlGetFrequency(value);
323 audio->ch2.control.stop = GBAAudioRegisterControlGetStop(value);
324 audio->ch2.control.endTime = (GBA_ARM7TDMI_FREQUENCY * (64 - audio->ch2.envelope.length)) >> 8;
325 if (GBAAudioRegisterControlIsRestart(value)) {
326 audio->playingCh2 = 1;
327 audio->ch2.envelope.currentVolume = audio->ch2.envelope.initialVolume;
328 if (audio->ch2.envelope.stepTime) {
329 audio->ch2.envelope.nextStep = 0;
330 } else {
331 audio->ch2.envelope.nextStep = INT_MAX;
332 }
333 audio->nextCh2 = 0;
334 }
335}
336
337void GBAAudioWriteSOUND3CNT_LO(struct GBAAudio* audio, uint16_t value) {
338 audio->ch3.bank.size = GBAAudioRegisterBankGetSize(value);
339 audio->ch3.bank.bank = GBAAudioRegisterBankGetBank(value);
340 audio->ch3.bank.enable = GBAAudioRegisterBankGetEnable(value);
341 if (audio->ch3.control.endTime >= 0) {
342 audio->playingCh3 = audio->ch3.bank.enable;
343 }
344}
345
346void GBAAudioWriteSOUND3CNT_HI(struct GBAAudio* audio, uint16_t value) {
347 audio->ch3.wave.length = GBAAudioRegisterBankWaveGetLength(value);
348 audio->ch3.wave.volume = GBAAudioRegisterBankWaveGetVolume(value);
349}
350
351void GBAAudioWriteSOUND3CNT_X(struct GBAAudio* audio, uint16_t value) {
352 audio->ch3.control.rate = GBAAudioRegisterControlGetRate(value);
353 audio->ch3.control.stop = GBAAudioRegisterControlGetStop(value);
354 audio->ch3.control.endTime = (GBA_ARM7TDMI_FREQUENCY * (256 - audio->ch3.wave.length)) >> 8;
355 if (GBAAudioRegisterControlIsRestart(value)) {
356 audio->playingCh3 = audio->ch3.bank.enable;
357 }
358}
359
360void GBAAudioWriteSOUND4CNT_LO(struct GBAAudio* audio, uint16_t value) {
361 if (!_writeEnvelope(&audio->ch4.envelope, value)) {
362 audio->ch4.sample = 0;
363 }
364}
365
366void GBAAudioWriteSOUND4CNT_HI(struct GBAAudio* audio, uint16_t value) {
367 audio->ch4.control.ratio = GBAAudioRegisterCh4ControlGetRatio(value);
368 audio->ch4.control.frequency = GBAAudioRegisterCh4ControlGetFrequency(value);
369 audio->ch4.control.power = GBAAudioRegisterCh4ControlGetPower(value);
370 audio->ch4.control.stop = GBAAudioRegisterCh4ControlGetStop(value);
371 audio->ch4.control.endTime = (GBA_ARM7TDMI_FREQUENCY * (64 - audio->ch4.envelope.length)) >> 8;
372 if (GBAAudioRegisterCh4ControlIsRestart(value)) {
373 audio->playingCh4 = 1;
374 audio->ch4.envelope.currentVolume = audio->ch4.envelope.initialVolume;
375 if (audio->ch4.envelope.stepTime) {
376 audio->ch4.envelope.nextStep = 0;
377 } else {
378 audio->ch4.envelope.nextStep = INT_MAX;
379 }
380 if (audio->ch4.control.power) {
381 audio->ch4.lfsr = 0x40;
382 } else {
383 audio->ch4.lfsr = 0x4000;
384 }
385 audio->nextCh4 = 0;
386 }
387}
388
389void GBAAudioWriteSOUNDCNT_LO(struct GBAAudio* audio, uint16_t value) {
390 audio->volumeRight = GBARegisterSOUNDCNT_LOGetVolumeRight(value);
391 audio->volumeLeft = GBARegisterSOUNDCNT_LOGetVolumeLeft(value);
392 audio->ch1Right = GBARegisterSOUNDCNT_LOGetCh1Right(value);
393 audio->ch2Right = GBARegisterSOUNDCNT_LOGetCh2Right(value);
394 audio->ch3Right = GBARegisterSOUNDCNT_LOGetCh3Right(value);
395 audio->ch4Right = GBARegisterSOUNDCNT_LOGetCh4Right(value);
396 audio->ch1Left = GBARegisterSOUNDCNT_LOGetCh1Left(value);
397 audio->ch2Left = GBARegisterSOUNDCNT_LOGetCh2Left(value);
398 audio->ch3Left = GBARegisterSOUNDCNT_LOGetCh3Left(value);
399 audio->ch4Left = GBARegisterSOUNDCNT_LOGetCh4Left(value);
400}
401
402void GBAAudioWriteSOUNDCNT_HI(struct GBAAudio* audio, uint16_t value) {
403 audio->volume = GBARegisterSOUNDCNT_HIGetVolume(value);
404 audio->volumeChA = GBARegisterSOUNDCNT_HIGetVolumeChA(value);
405 audio->volumeChB = GBARegisterSOUNDCNT_HIGetVolumeChB(value);
406 audio->chARight = GBARegisterSOUNDCNT_HIGetChARight(value);
407 audio->chALeft = GBARegisterSOUNDCNT_HIGetChALeft(value);
408 audio->chATimer = GBARegisterSOUNDCNT_HIGetChATimer(value);
409 audio->chBRight = GBARegisterSOUNDCNT_HIGetChBRight(value);
410 audio->chBLeft = GBARegisterSOUNDCNT_HIGetChBLeft(value);
411 audio->chBTimer = GBARegisterSOUNDCNT_HIGetChBTimer(value);
412 // TODO: Implement channel reset
413}
414
415void GBAAudioWriteSOUNDCNT_X(struct GBAAudio* audio, uint16_t value) {
416 audio->enable = GBARegisterSOUNDCNT_XGetEnable(value);
417}
418
419void GBAAudioWriteSOUNDBIAS(struct GBAAudio* audio, uint16_t value) {
420 audio->soundbias = value;
421}
422
423void GBAAudioWriteWaveRAM(struct GBAAudio* audio, int address, uint32_t value) {
424 audio->ch3.wavedata[address | (!audio->ch3.bank.bank * 4)] = value;
425}
426
427void GBAAudioWriteFIFO(struct GBAAudio* audio, int address, uint32_t value) {
428 struct CircleBuffer* fifo;
429 switch (address) {
430 case REG_FIFO_A_LO:
431 fifo = &audio->chA.fifo;
432 break;
433 case REG_FIFO_B_LO:
434 fifo = &audio->chB.fifo;
435 break;
436 default:
437 GBALog(audio->p, GBA_LOG_ERROR, "Bad FIFO write to address 0x%03x", address);
438 return;
439 }
440 while (!CircleBufferWrite32(fifo, value)) {
441 int32_t dummy;
442 CircleBufferRead32(fifo, &dummy);
443 }
444}
445
446void GBAAudioSampleFIFO(struct GBAAudio* audio, int fifoId, int32_t cycles) {
447 struct GBAAudioFIFO* channel;
448 if (fifoId == 0) {
449 channel = &audio->chA;
450 } else if (fifoId == 1) {
451 channel = &audio->chB;
452 } else {
453 GBALog(audio->p, GBA_LOG_ERROR, "Bad FIFO write to address 0x%03x", fifoId);
454 return;
455 }
456 if (CircleBufferSize(&channel->fifo) <= 4 * sizeof(int32_t)) {
457 struct GBADMA* dma = &audio->p->memory.dma[channel->dmaSource];
458 dma->nextCount = 4;
459 dma->nextEvent = 0;
460 GBAMemoryUpdateDMAs(audio->p, -cycles);
461 }
462 CircleBufferRead8(&channel->fifo, &channel->sample);
463}
464
465unsigned GBAAudioCopy(struct GBAAudio* audio, void* left, void* right, unsigned nSamples) {
466 GBASyncLockAudio(audio->p->sync);
467 unsigned read = 0;
468 if (left) {
469 unsigned readL = CircleBufferRead(&audio->left, left, nSamples * sizeof(int32_t)) >> 2;
470 if (readL < nSamples) {
471 memset((int32_t*) left + readL, 0, nSamples - readL);
472 }
473 read = readL;
474 }
475 if (right) {
476 unsigned readR = CircleBufferRead(&audio->right, right, nSamples * sizeof(int32_t)) >> 2;
477 if (readR < nSamples) {
478 memset((int32_t*) right + readR, 0, nSamples - readR);
479 }
480 read = read >= readR ? read : readR;
481 }
482 GBASyncConsumeAudio(audio->p->sync);
483 return read;
484}
485
486unsigned GBAAudioResampleNN(struct GBAAudio* audio, float ratio, float* drift, struct GBAStereoSample* output, unsigned nSamples) {
487 int32_t left[GBA_AUDIO_SAMPLES];
488 int32_t right[GBA_AUDIO_SAMPLES];
489
490 // toRead is in GBA samples
491 // TODO: Do this with fixed-point math
492 unsigned toRead = ceilf(nSamples / ratio);
493 unsigned totalRead = 0;
494 while (nSamples) {
495 unsigned currentRead = GBA_AUDIO_SAMPLES;
496 if (currentRead > toRead) {
497 currentRead = toRead;
498 }
499 unsigned read = GBAAudioCopy(audio, left, right, currentRead);
500 toRead -= read;
501 unsigned i;
502 for (i = 0; i < read; ++i) {
503 *drift += ratio;
504 while (*drift >= 1.f) {
505 output->left = left[i];
506 output->right = right[i];
507 ++output;
508 ++totalRead;
509 --nSamples;
510 *drift -= 1.f;
511 if (!nSamples) {
512 return totalRead;
513 }
514 }
515 }
516 if (read < currentRead) {
517 memset(output, 0, nSamples * sizeof(struct GBAStereoSample));
518 break;
519 }
520 }
521 return totalRead;
522}
523
524bool _writeEnvelope(struct GBAAudioEnvelope* envelope, uint16_t value) {
525 envelope->length = GBAAudioRegisterEnvelopeGetLength(value);
526 envelope->duty = GBAAudioRegisterEnvelopeGetDuty(value);
527 envelope->stepTime = GBAAudioRegisterEnvelopeGetStepTime(value);
528 envelope->direction = GBAAudioRegisterEnvelopeGetDirection(value);
529 envelope->initialVolume = GBAAudioRegisterEnvelopeGetInitialVolume(value);
530 envelope->dead = 0;
531 if (envelope->stepTime) {
532 envelope->nextStep = 0;
533 } else {
534 envelope->nextStep = INT_MAX;
535 if (envelope->initialVolume == 0) {
536 envelope->dead = 1;
537 return false;
538 }
539 }
540 return true;
541}
542
543static int32_t _updateSquareChannel(struct GBAAudioSquareControl* control, int duty) {
544 control->hi = !control->hi;
545 int period = 16 * (2048 - control->frequency);
546 switch (duty) {
547 case 0:
548 return control->hi ? period : period * 7;
549 case 1:
550 return control->hi ? period * 2 : period * 6;
551 case 2:
552 return period * 4;
553 case 3:
554 return control->hi ? period * 6 : period * 2;
555 default:
556 // This should never be hit
557 return period * 4;
558 }
559}
560
561static void _updateEnvelope(struct GBAAudioEnvelope* envelope) {
562 if (envelope->direction) {
563 ++envelope->currentVolume;
564 } else {
565 --envelope->currentVolume;
566 }
567 if (envelope->currentVolume >= 15) {
568 envelope->currentVolume = 15;
569 envelope->nextStep = INT_MAX;
570 } else if (envelope->currentVolume <= 0) {
571 envelope->currentVolume = 0;
572 envelope->dead = 1;
573 envelope->nextStep = INT_MAX;
574 } else {
575 envelope->nextStep += envelope->stepTime * (GBA_ARM7TDMI_FREQUENCY >> 6);
576 }
577}
578
579static bool _updateSweep(struct GBAAudioChannel1* ch) {
580 if (ch->sweep.direction) {
581 int frequency = ch->control.frequency;
582 frequency -= frequency >> ch->sweep.shift;
583 if (frequency >= 0) {
584 ch->control.frequency = frequency;
585 }
586 } else {
587 int frequency = ch->control.frequency;
588 frequency += frequency >> ch->sweep.shift;
589 if (frequency < 2048) {
590 ch->control.frequency = frequency;
591 } else {
592 return false;
593 }
594 }
595 ch->nextSweep += ch->sweep.time * SWEEP_CYCLES;
596 return true;
597}
598
599static int32_t _updateChannel1(struct GBAAudioChannel1* ch) {
600 int timing = _updateSquareChannel(&ch->control, ch->envelope.duty);
601 ch->sample = ch->control.hi * 0x10 - 0x8;
602 ch->sample *= ch->envelope.currentVolume;
603 return timing;
604}
605
606static int32_t _updateChannel2(struct GBAAudioChannel2* ch) {
607 int timing = _updateSquareChannel(&ch->control, ch->envelope.duty);
608 ch->sample = ch->control.hi * 0x10 - 0x8;
609 ch->sample *= ch->envelope.currentVolume;
610 return timing;
611}
612
613static int32_t _updateChannel3(struct GBAAudioChannel3* ch) {
614 int i;
615 int start;
616 int end;
617 int volume;
618 switch (ch->wave.volume) {
619 case 0:
620 volume = 0;
621 break;
622 case 1:
623 volume = 4;
624 break;
625 case 2:
626 volume = 2;
627 break;
628 case 3:
629 volume = 1;
630 break;
631 default:
632 volume = 3;
633 break;
634 }
635 if (ch->bank.size) {
636 start = 7;
637 end = 0;
638 } else if (ch->bank.bank) {
639 start = 7;
640 end = 4;
641 } else {
642 start = 3;
643 end = 0;
644 }
645 uint32_t bitsCarry = ch->wavedata[end] & 0x0F000000;
646 uint32_t bits;
647 for (i = start; i >= end; --i) {
648 bits = ch->wavedata[i] & 0x0F000000;
649 ch->wavedata[i] = ((ch->wavedata[i] & 0xF0F0F0F0) >> 4) | ((ch->wavedata[i] & 0x000F0F0F) << 12);
650 ch->wavedata[i] |= bitsCarry >> 20;
651 bitsCarry = bits;
652 }
653 ch->sample = (bitsCarry >> 20);
654 ch->sample >>= 2;
655 ch->sample *= volume;
656 return 8 * (2048 - ch->control.rate);
657}
658
659static int32_t _updateChannel4(struct GBAAudioChannel4* ch) {
660 int lsb = ch->lfsr & 1;
661 ch->sample = lsb * 0x10 - 0x8;
662 ch->sample *= ch->envelope.currentVolume;
663 ch->lfsr >>= 1;
664 ch->lfsr ^= (lsb * 0x60) << (ch->control.power ? 0 : 8);
665 int timing = ch->control.ratio ? 2 * ch->control.ratio : 1;
666 timing <<= ch->control.frequency;
667 timing *= 32;
668 return timing;
669}
670
671static int _applyBias(struct GBAAudio* audio, int sample) {
672 sample += audio->bias;
673 if (sample >= 0x400) {
674 sample = 0x3FF;
675 } else if (sample < 0) {
676 sample = 0;
677 }
678 return (sample - audio->bias) << 6;
679}
680
681static void _sample(struct GBAAudio* audio) {
682 int32_t sampleLeft = 0;
683 int32_t sampleRight = 0;
684 int psgShift = 6 - audio->volume;
685
686 if (audio->ch1Left) {
687 sampleLeft += audio->ch1.sample;
688 }
689
690 if (audio->ch1Right) {
691 sampleRight += audio->ch1.sample;
692 }
693
694 if (audio->ch2Left) {
695 sampleLeft += audio->ch2.sample;
696 }
697
698 if (audio->ch2Right) {
699 sampleRight += audio->ch2.sample;
700 }
701
702 if (audio->ch3Left) {
703 sampleLeft += audio->ch3.sample;
704 }
705
706 if (audio->ch3Right) {
707 sampleRight += audio->ch3.sample;
708 }
709
710 if (audio->ch4Left) {
711 sampleLeft += audio->ch4.sample;
712 }
713
714 if (audio->ch4Right) {
715 sampleRight += audio->ch4.sample;
716 }
717
718 sampleLeft = (sampleLeft * (1 + audio->volumeLeft)) >> psgShift;
719 sampleRight = (sampleRight * (1 + audio->volumeRight)) >> psgShift;
720
721 if (audio->chALeft) {
722 sampleLeft += (audio->chA.sample << 2) >> !audio->volumeChA;
723 }
724
725 if (audio->chARight) {
726 sampleRight += (audio->chA.sample << 2) >> !audio->volumeChA;
727 }
728
729 if (audio->chBLeft) {
730 sampleLeft += (audio->chB.sample << 2) >> !audio->volumeChB;
731 }
732
733 if (audio->chBRight) {
734 sampleRight += (audio->chB.sample << 2) >> !audio->volumeChB;
735 }
736
737 sampleLeft = _applyBias(audio, sampleLeft);
738 sampleRight = _applyBias(audio, sampleRight);
739
740 GBASyncLockAudio(audio->p->sync);
741 CircleBufferWrite32(&audio->left, sampleLeft);
742 CircleBufferWrite32(&audio->right, sampleRight);
743 unsigned produced = CircleBufferSize(&audio->left);
744 struct GBAThread* thread = GBAThreadGetContext();
745 if (thread && thread->stream) {
746 thread->stream->postAudioFrame(thread->stream, sampleLeft, sampleRight);
747 }
748 GBASyncProduceAudio(audio->p->sync, produced >= CircleBufferCapacity(&audio->left) / sizeof(int32_t) * 3);
749}
750
751void GBAAudioSerialize(const struct GBAAudio* audio, struct GBASerializedState* state) {
752 state->audio.ch1Volume = audio->ch1.envelope.currentVolume;
753 state->audio.ch1Dead = audio->ch1.envelope.dead;
754 state->audio.ch1Hi = audio->ch1.control.hi;
755 state->audio.ch1.envelopeNextStep = audio->ch1.envelope.nextStep;
756 state->audio.ch1.waveNextStep = audio->ch1.control.nextStep;
757 state->audio.ch1.sweepNextStep = audio->ch1.nextSweep;
758 state->audio.ch1.endTime = audio->ch1.control.endTime;
759 state->audio.ch1.nextEvent = audio->nextCh1;
760
761 state->audio.ch2Volume = audio->ch2.envelope.currentVolume;
762 state->audio.ch2Dead = audio->ch2.envelope.dead;
763 state->audio.ch2Hi = audio->ch2.control.hi;
764 state->audio.ch2.envelopeNextStep = audio->ch2.envelope.nextStep;
765 state->audio.ch2.waveNextStep = audio->ch2.control.nextStep;
766 state->audio.ch2.endTime = audio->ch2.control.endTime;
767 state->audio.ch2.nextEvent = audio->nextCh2;
768
769 memcpy(state->audio.ch3.wavebanks, audio->ch3.wavedata, sizeof(state->audio.ch3.wavebanks));
770 state->audio.ch3.endTime = audio->ch3.control.endTime;
771 state->audio.ch3.nextEvent = audio->nextCh3;
772
773 state->audio.ch4Volume = audio->ch4.envelope.currentVolume;
774 state->audio.ch4Dead = audio->ch4.envelope.dead;
775 state->audio.ch4.envelopeNextStep = audio->ch4.envelope.nextStep;
776 state->audio.ch4.lfsr = audio->ch4.lfsr;
777 state->audio.ch4.endTime = audio->ch4.control.endTime;
778 state->audio.ch4.nextEvent = audio->nextCh4;
779
780 CircleBufferDump(&audio->chA.fifo, state->audio.fifoA, sizeof(state->audio.fifoA));
781 CircleBufferDump(&audio->chB.fifo, state->audio.fifoB, sizeof(state->audio.fifoB));
782 state->audio.fifoSize = CircleBufferSize(&audio->chA.fifo);
783
784 state->audio.nextEvent = audio->nextEvent;
785 state->audio.eventDiff = audio->eventDiff;
786 state->audio.nextSample = audio->nextSample;
787}
788
789void GBAAudioDeserialize(struct GBAAudio* audio, const struct GBASerializedState* state) {
790 audio->ch1.envelope.currentVolume = state->audio.ch1Volume;
791 audio->ch1.envelope.dead = state->audio.ch1Dead;
792 audio->ch1.control.hi = state->audio.ch1Hi;
793 audio->ch1.envelope.nextStep = state->audio.ch1.envelopeNextStep;
794 audio->ch1.control.nextStep = state->audio.ch1.waveNextStep;
795 audio->ch1.nextSweep = state->audio.ch1.sweepNextStep;
796 audio->ch1.control.endTime = state->audio.ch1.endTime;
797 audio->nextCh1 = state->audio.ch1.nextEvent;
798
799 audio->ch2.envelope.currentVolume = state->audio.ch2Volume;
800 audio->ch2.envelope.dead = state->audio.ch2Dead;
801 audio->ch2.control.hi = state->audio.ch2Hi;
802 audio->ch2.envelope.nextStep = state->audio.ch2.envelopeNextStep;
803 audio->ch2.control.nextStep = state->audio.ch2.waveNextStep;
804 audio->ch2.control.endTime = state->audio.ch2.endTime;
805 audio->nextCh2 = state->audio.ch2.nextEvent;
806
807 memcpy(audio->ch3.wavedata, state->audio.ch3.wavebanks, sizeof(audio->ch3.wavedata));
808 audio->ch3.control.endTime = state->audio.ch3.endTime;
809 audio->nextCh3 = state->audio.ch3.nextEvent;
810
811 audio->ch4.envelope.currentVolume = state->audio.ch4Volume;
812 audio->ch4.envelope.dead = state->audio.ch4Dead;
813 audio->ch4.envelope.nextStep = state->audio.ch4.envelopeNextStep;
814 audio->ch4.lfsr = state->audio.ch4.lfsr;
815 audio->ch4.control.endTime = state->audio.ch4.endTime;
816 audio->nextCh4 = state->audio.ch4.nextEvent;
817
818 CircleBufferClear(&audio->chA.fifo);
819 CircleBufferClear(&audio->chB.fifo);
820 int i;
821 for (i = 0; i < state->audio.fifoSize; ++i) {
822 CircleBufferWrite8(&audio->chA.fifo, state->audio.fifoA[i]);
823 CircleBufferWrite8(&audio->chB.fifo, state->audio.fifoB[i]);
824 }
825
826 audio->nextEvent = state->audio.nextEvent;
827 audio->eventDiff = state->audio.eventDiff;
828 audio->nextSample = state->audio.nextSample;
829}
830
831float GBAAudioCalculateRatio(struct GBAAudio* audio, float desiredFPS, float desiredSampleRate) {
832 return desiredSampleRate * GBA_ARM7TDMI_FREQUENCY / (VIDEO_TOTAL_LENGTH * desiredFPS * audio->sampleRate);
833}