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Partially implement SOUNDBIAS

This commit is contained in:
Jeffrey Pfau 2014-02-03 05:22:29 -08:00
parent 683e90fa06
commit 8f241e2cfb
3 changed files with 36 additions and 3 deletions
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23
src/gba/gba-audio.c
View File

@ -19,6 +19,7 @@ static int32_t _updateChannel1(struct GBAAudioChannel1* ch);
static int32_t _updateChannel2(struct GBAAudioChannel2* ch);
static int32_t _updateChannel3(struct GBAAudioChannel3* ch);
static int32_t _updateChannel4(struct GBAAudioChannel4* ch);
static int _applyBias(struct GBAAudio* audio, int sample);
static void _sample(struct GBAAudio* audio);
void GBAAudioInit(struct GBAAudio* audio) {
@ -45,6 +46,7 @@ void GBAAudioInit(struct GBAAudio* audio) {
audio->eventDiff = 0;
audio->nextSample = 0;
audio->sampleRate = 0x8000;
audio->soundbias = 0x200;
audio->soundcntLo = 0;
audio->soundcntHi = 0;
audio->soundcntX = 0;
@ -357,6 +359,10 @@ void GBAAudioWriteSOUNDCNT_X(struct GBAAudio* audio, uint16_t value) {
audio->soundcntX = (value & 0x80) | (audio->soundcntX & 0x0F);
}
void GBAAudioWriteSOUNDBIAS(struct GBAAudio* audio, uint16_t value) {
audio->soundbias = value;
}
void GBAAudioWriteWaveRAM(struct GBAAudio* audio, int address, uint32_t value) {
audio->ch3.wavedata[address | (!audio->ch3.bank.bank * 4)] = value;
}
@ -584,6 +590,16 @@ static int32_t _updateChannel4(struct GBAAudioChannel4* ch) {
return timing;
}
static int _applyBias(struct GBAAudio* audio, int sample) {
sample += audio->bias;
if (sample >= 0x400) {
sample = 0x3FF;
} else if (sample < 0) {
sample = 0;
}
return (sample - audio->bias) << 6;
}
static void _sample(struct GBAAudio* audio) {
int32_t sampleLeft = 0;
int32_t sampleRight = 0;
@ -640,9 +656,12 @@ static void _sample(struct GBAAudio* audio) {
sampleRight += (audio->chB.sample << 2) >> !audio->volumeChB;
}
sampleLeft = _applyBias(audio, sampleLeft);
sampleRight = _applyBias(audio, sampleRight);
GBASyncLockAudio(audio->p->sync);
CircleBufferWrite32(&audio->left, sampleLeft << 5);
CircleBufferWrite32(&audio->right, sampleRight << 5);
CircleBufferWrite32(&audio->left, sampleLeft);
CircleBufferWrite32(&audio->right, sampleRight);
unsigned produced = CircleBufferSize(&audio->left);
GBASyncProduceAudio(audio->p->sync, produced >= GBA_AUDIO_SAMPLES * 3);
}

10
src/gba/gba-audio.h
View File

@ -193,6 +193,15 @@ struct GBAAudio {
unsigned sampleRate;
union {
struct {
unsigned bias : 10;
unsigned : 4;
unsigned resolution : 2;
};
uint16_t soundbias;
};
int32_t nextEvent;
int32_t eventDiff;
int32_t nextCh1;
@ -228,6 +237,7 @@ void GBAAudioWriteSOUND4CNT_HI(struct GBAAudio* audio, uint16_t value);
void GBAAudioWriteSOUNDCNT_LO(struct GBAAudio* audio, uint16_t value);
void GBAAudioWriteSOUNDCNT_HI(struct GBAAudio* audio, uint16_t value);
void GBAAudioWriteSOUNDCNT_X(struct GBAAudio* audio, uint16_t value);
void GBAAudioWriteSOUNDBIAS(struct GBAAudio* audio, uint16_t value);
void GBAAudioWriteWaveRAM(struct GBAAudio* audio, int address, uint32_t value);
void GBAAudioWriteFIFO(struct GBAAudio* audio, int address, uint32_t value);

6
src/gba/gba-io.c
View File

@ -17,7 +17,7 @@ static const int _isValidRegister[REG_MAX >> 1] = {
1, 1, 1, 0, 1, 0, 1, 0,
1, 1, 1, 0, 1, 0, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 0, 0, 0, 0,
1, 1, 1, 1, 1, 0, 0, 0,
// DMA
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
@ -92,6 +92,7 @@ void GBAIOInit(struct GBA* gba) {
gba->memory.io[REG_DISPCNT >> 1] = 0x0080;
gba->memory.io[REG_RCNT >> 1] = RCNT_INITIAL;
gba->memory.io[REG_KEYINPUT >> 1] = 0x3FF;
gba->memory.io[REG_SOUNDBIAS >> 1] = 0x200;
}
void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
@ -153,6 +154,9 @@ void GBAIOWrite(struct GBA* gba, uint32_t address, uint16_t value) {
case REG_SOUNDCNT_X:
GBAAudioWriteSOUNDCNT_X(&gba->audio, value);
break;
case REG_SOUNDBIAS:
GBAAudioWriteSOUNDBIAS(&gba->audio, value);
break;
case REG_WAVE_RAM0_LO:
case REG_WAVE_RAM1_LO: