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GB Audio: Migrate channel 4 into GBRunAudio

This commit is contained in:
Vicki Pfau 2022-05-31 21:24:50 -07:00
parent 68f628a211
commit 779e7bc94b
3 changed files with 24 additions and 41 deletions
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2
include/mgba/internal/gb/audio.h
View File

@ -197,7 +197,6 @@ struct GBAudio {
struct mTimingEvent frameEvent;
struct mTimingEvent ch3Event;
struct mTimingEvent ch3Fade;
struct mTimingEvent ch4Event;
struct mTimingEvent sampleEvent;
bool enable;
@ -240,7 +239,6 @@ void GBAudioWriteNR52(struct GBAudio* audio, uint8_t);
void GBAudioRun(struct GBAudio* audio, int32_t timestamp);
void GBAudioUpdateFrame(struct GBAudio* audio);
void GBAudioUpdateChannel4(struct GBAudio* audio);
void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right);

61
src/gb/audio.c
View File

@ -83,10 +83,6 @@ void GBAudioInit(struct GBAudio* audio, size_t samples, uint8_t* nr52, enum GBAu
audio->ch3Fade.name = "GB Audio Channel 3 Memory";
audio->ch3Fade.callback = _fadeChannel3;
audio->ch3Fade.priority = 0x14;
audio->ch4Event.context = audio;
audio->ch4Event.name = "GB Audio Channel 4";
audio->ch4Event.callback = NULL; // This is pending removal, so calling it will crash
audio->ch4Event.priority = 0x15;
audio->sampleEvent.context = audio;
audio->sampleEvent.name = "GB Audio Sample";
audio->sampleEvent.callback = _sample;
@ -102,7 +98,6 @@ void GBAudioReset(struct GBAudio* audio) {
mTimingDeschedule(audio->timing, &audio->frameEvent);
mTimingDeschedule(audio->timing, &audio->ch3Event);
mTimingDeschedule(audio->timing, &audio->ch3Fade);
mTimingDeschedule(audio->timing, &audio->ch4Event);
mTimingDeschedule(audio->timing, &audio->sampleEvent);
if (audio->style != GB_AUDIO_GBA) {
mTimingSchedule(audio->timing, &audio->sampleEvent, 0);
@ -335,13 +330,13 @@ void GBAudioWriteNR34(struct GBAudio* audio, uint8_t value) {
}
void GBAudioWriteNR41(struct GBAudio* audio, uint8_t value) {
GBAudioUpdateChannel4(audio);
GBAudioRun(audio, mTimingCurrentTime(audio->timing));
_writeDuty(&audio->ch4.envelope, value);
audio->ch4.length = 64 - audio->ch4.envelope.length;
}
void GBAudioWriteNR42(struct GBAudio* audio, uint8_t value) {
GBAudioUpdateChannel4(audio);
GBAudioRun(audio, mTimingCurrentTime(audio->timing));
if (!_writeEnvelope(&audio->ch4.envelope, value, audio->style)) {
audio->playingCh4 = false;
*audio->nr52 &= ~0x0008;
@ -349,14 +344,14 @@ void GBAudioWriteNR42(struct GBAudio* audio, uint8_t value) {
}
void GBAudioWriteNR43(struct GBAudio* audio, uint8_t value) {
GBAudioUpdateChannel4(audio);
GBAudioRun(audio, mTimingCurrentTime(audio->timing));
audio->ch4.ratio = GBAudioRegisterNoiseFeedbackGetRatio(value);
audio->ch4.frequency = GBAudioRegisterNoiseFeedbackGetFrequency(value);
audio->ch4.power = GBAudioRegisterNoiseFeedbackGetPower(value);
}
void GBAudioWriteNR44(struct GBAudio* audio, uint8_t value) {
GBAudioUpdateChannel4(audio);
GBAudioRun(audio, mTimingCurrentTime(audio->timing));
bool wasStop = audio->ch4.stop;
audio->ch4.stop = GBAudioRegisterNoiseControlGetStop(value);
if (!wasStop && audio->ch4.stop && audio->ch4.length && !(audio->frame & 1)) {
@ -379,7 +374,7 @@ void GBAudioWriteNR44(struct GBAudio* audio, uint8_t value) {
--audio->ch4.length;
}
}
if (audio->playingCh4 && audio->ch4.envelope.dead != 2) {
if (audio->playingCh4) {
audio->ch4.lastEvent = mTimingCurrentTime(audio->timing);
}
}
@ -498,6 +493,24 @@ void GBAudioRun(struct GBAudio* audio, int32_t timestamp) {
audio->ch2.lastUpdate += diff * period;
_updateSquareSample(&audio->ch2);
}
if (audio->playingCh4) {
int32_t cycles = audio->ch4.ratio ? 2 * audio->ch4.ratio : 1;
cycles <<= audio->ch4.frequency;
cycles *= 8 * audio->timingFactor;
int32_t last = 0;
int32_t diff = timestamp - audio->ch4.lastEvent;
for (; last + cycles <= diff; last += cycles) {
int lsb = audio->ch4.lfsr & 1;
audio->ch4.sample = lsb * audio->ch4.envelope.currentVolume;
++audio->ch4.nSamples;
audio->ch4.samples += audio->ch4.sample;
audio->ch4.lfsr >>= 1;
audio->ch4.lfsr ^= (lsb * 0x60) << (audio->ch4.power ? 0 : 8);
}
audio->ch4.lastEvent += last;
}
}
void GBAudioUpdateFrame(struct GBAudio* audio) {
@ -555,7 +568,6 @@ void GBAudioUpdateFrame(struct GBAudio* audio) {
if (audio->ch4.length && audio->ch4.stop) {
--audio->ch4.length;
if (audio->ch4.length == 0) {
GBAudioUpdateChannel4(audio);
audio->playingCh4 = 0;
*audio->nr52 &= ~0x0008;
}
@ -581,7 +593,6 @@ void GBAudioUpdateFrame(struct GBAudio* audio) {
if (audio->playingCh4 && !audio->ch4.envelope.dead) {
--audio->ch4.envelope.nextStep;
if (audio->ch4.envelope.nextStep == 0) {
GBAudioUpdateChannel4(audio);
int8_t sample = audio->ch4.sample;
_updateEnvelope(&audio->ch4.envelope);
audio->ch4.sample = (sample > 0) * audio->ch4.envelope.currentVolume;
@ -595,31 +606,6 @@ void GBAudioUpdateFrame(struct GBAudio* audio) {
}
}
void GBAudioUpdateChannel4(struct GBAudio* audio) {
struct GBAudioNoiseChannel* ch = &audio->ch4;
if (ch->envelope.dead == 2 || !audio->playingCh4) {
return;
}
int32_t cycles = ch->ratio ? 2 * ch->ratio : 1;
cycles <<= ch->frequency;
cycles *= 8 * audio->timingFactor;
uint32_t last = 0;
uint32_t now = mTimingCurrentTime(audio->timing) - ch->lastEvent;
for (; last + cycles <= now; last += cycles) {
int lsb = ch->lfsr & 1;
ch->sample = lsb * ch->envelope.currentVolume;
++ch->nSamples;
ch->samples += ch->sample;
ch->lfsr >>= 1;
ch->lfsr ^= (lsb * 0x60) << (ch->power ? 0 : 8);
}
ch->lastEvent += last;
}
void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right) {
GBAudioRun(audio, mTimingCurrentTime(audio->timing));
int dcOffset = audio->style == GB_AUDIO_GBA ? 0 : -0x8;
@ -660,7 +646,6 @@ void GBAudioSamplePSG(struct GBAudio* audio, int16_t* left, int16_t* right) {
sampleRight <<= 3;
if (!audio->forceDisableCh[3]) {
GBAudioUpdateChannel4(audio);
int16_t sample = audio->style == GB_AUDIO_GBA ? (audio->ch4.sample << 3) : _coalesceNoiseChannel(&audio->ch4);
if (audio->ch4Left) {
sampleLeft += sample;

2
src/gb/io.c
View File

@ -628,7 +628,7 @@ uint8_t GBIORead(struct GB* gb, unsigned address) {
if (gb->model < GB_MODEL_CGB) {
mLOG(GB_IO, GAME_ERROR, "Reading from CGB register FF%02X in DMG mode", address);
} else if (gb->audio.enable) {
GBAudioUpdateChannel4(&gb->audio);
GBAudioRun(&gb->audio, mTimingCurrentTime(gb->audio.timing));
return (gb->audio.ch3.sample) | (gb->audio.ch4.sample << 4);
}
break;