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-improved audio output and small audio emulation fixes and improvements
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-added support for one of the multicarts I own because why not
-various small updates regarding the libretro hook, including better handling of rom switching and saving
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@FIX94
FIX94 committed Oct 31, 2018
1 parent 0004be6 commit 251e12c
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Showing 8 changed files with 508 additions and 338 deletions.
176 changes: 84 additions & 92 deletions apu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -53,10 +53,10 @@ static uint8_t p1LengthCtr, p2LengthCtr, noiseLengthCtr;
static uint8_t wavLinearCtr;
static uint16_t wavLengthCtr;
static uint8_t wavVolShift;
static uint16_t modeCurCtr = 0;
static uint16_t modeCurCtr;
static uint8_t modePos;
static uint16_t p1freqCtr, p2freqCtr, wavFreqCtr, noiseFreqCtr;
static uint8_t p1Cycle, p2Cycle, wavCycle;
static uint8_t modePos = 0;
static bool p1haltloop, p2haltloop, wavhaltloop, noisehaltloop;
static bool p1dacenable, p2dacenable, wavdacenable, noisedacenable;
static bool p1enable, p2enable, wavenable, noiseenable;
Expand Down Expand Up @@ -118,16 +118,16 @@ void apuInitBufs()
apuFrequency = 262144;
double dt = 1.0/((double)apuFrequency);

//LP at 22kHz
double rc = 1.0/(M_2_PI * 22000.0);
//LP at 20kHz
double rc = 1.0/(M_2_PI * 20000.0);
#if AUDIO_FLOAT
lpVal = dt / (rc + dt);
#else
//convert to 32bit int for calcs later
lpVal = (int32_t)((dt / (rc + dt))*32768.0);
#endif
//HP at 40Hz
rc = 1.0/(M_2_PI * 40.0);
//HP at 20Hz for GB/GBA (150Hz for GBC)
rc = 1.0/(M_2_PI * 20.0);
#if AUDIO_FLOAT
hpVal = rc / (rc + dt);
#else
Expand All @@ -154,6 +154,16 @@ void apuDeinitBufs()
apuOutBuf = NULL;
}

#if AUDIO_FLOAT
static float lastHPOutLeft, lastHPOutRight, lastLPOutLeft, lastLPOutRight;
#else
static int32_t lastHPOutLeft, lastHPOutRight, lastLPOutLeft, lastLPOutRight;
#endif
//used externally
uint8_t curP1Out, curP2Out, curWavOut, curNoiseOut;

extern bool emuSkipVsync, emuSkipFrame;

extern bool gbCgbMode;
extern bool gbCgbBootrom;
void apuInit()
Expand All @@ -166,8 +176,11 @@ void apuInit()
memset(apuOutBuf, 0, apuBufSizeBytes);
curBufPos = 0;

modeCurCtr = 0;
modePos = 0;

freq1 = 0; freq2 = 0; wavFreq = 0; noiseFreq = 0;
noiseShiftReg = 1;
noiseShiftReg = 0;
p1LengthCtr = 0; p2LengthCtr = 0;
noiseLengthCtr = 0; wavLengthCtr = 0;
wavLinearCtr = 0;
Expand Down Expand Up @@ -197,18 +210,10 @@ void apuInit()
APU_IO_Reg[0x24] = 0x77;
APU_IO_Reg[0x25] = 0xF3;
}
}

#if AUDIO_FLOAT
static float lastHPOutLeft = 0, lastHPOutRight = 0, lastLPOutLeft = 0, lastLPOutRight = 0;
#else
static int32_t lastHPOutLeft = 0, lastHPOutRight = 0, lastLPOutLeft = 0, lastLPOutRight = 0;
#endif
static uint8_t lastP1OutLeft = 0, lastP2OutLeft = 0, lastWavOutLeft = 0, lastNoiseOutLeft = 0;
static uint8_t lastP1OutRight = 0, lastP2OutRight = 0, lastWavOutRight = 0, lastNoiseOutRight = 0;
extern bool emuSkipVsync, emuSkipFrame;
//used externally
uint8_t curP1Out = 0, curP2Out = 0, curWavOut = 0, curNoiseOut = 0;
lastHPOutLeft = 0, lastHPOutRight = 0, lastLPOutLeft = 0, lastLPOutRight = 0;
curP1Out = 0, curP2Out = 0, curWavOut = 0, curNoiseOut = 0;
}

bool apuCycle()
{
Expand Down Expand Up @@ -238,108 +243,100 @@ bool apuCycle()
#endif
curBufPos = 0;
}
uint8_t p1OutLeft = lastP1OutLeft, p2OutLeft = lastP2OutLeft,
wavOutLeft = lastWavOutLeft, noiseOutLeft = lastNoiseOutLeft;
uint8_t p1OutRight = lastP1OutRight, p2OutRight = lastP2OutRight,
wavOutRight = lastWavOutRight, noiseOutRight = lastNoiseOutRight;
uint8_t apuMasterVolLeft = ((APU_IO_Reg[0x24]>>4)&7), apuMasterVolRight = (APU_IO_Reg[0x24]&7);
int8_t p1Out = 0, p2Out = 0, noiseOut = 0, wavOut = 0;
int8_t p1OutLeft = 0, p2OutLeft = 0,
wavOutLeft = 0, noiseOutLeft = 0;
int8_t p1OutRight = 0, p2OutRight = 0,
wavOutRight = 0, noiseOutRight = 0;
int8_t apuMasterVolLeft = ((APU_IO_Reg[0x24]>>4)&7), apuMasterVolRight = (APU_IO_Reg[0x24]&7);
if(p1enable && p1dacenable)
{
if(p1seq[p1Cycle] && freq1 > 0 && freq1 < 0x7FF)
{
if(p1seq[p1Cycle])
curP1Out = p1Env.curVol;
if(APU_IO_Reg[0x25] & P1_ENABLE_LEFT)
lastP1OutLeft = p1OutLeft = curP1Out;
if(APU_IO_Reg[0x25] & P1_ENABLE_RIGHT)
lastP1OutRight = p1OutRight = curP1Out;
}
else
{
curP1Out = 0;
if(APU_IO_Reg[0x25] & P1_ENABLE_LEFT)
p1OutLeft = 0;
if(APU_IO_Reg[0x25] & P1_ENABLE_RIGHT)
p1OutRight = 0;
//actually audible output
if(freq1 > 0 && freq1 < 0x7FF)
{
//GB/GBC Behavior
//p1Out = (curP1Out<<1)-15;
//GBA Behavior
p1Out = (curP1Out<<1)-p1Env.curVol;
}
}
else
curP1Out = 0;
if(APU_IO_Reg[0x25] & P1_ENABLE_LEFT)
p1OutLeft = p1Out;
if(APU_IO_Reg[0x25] & P1_ENABLE_RIGHT)
p1OutRight = p1Out;
if(p2enable && p2dacenable)
{
if(p2seq[p2Cycle] && freq2 > 0 && freq2 < 0x7FF)
{
if(p2seq[p2Cycle])
curP2Out = p2Env.curVol;
if(APU_IO_Reg[0x25] & P2_ENABLE_LEFT)
lastP2OutLeft = p2OutLeft = curP2Out;
if(APU_IO_Reg[0x25] & P2_ENABLE_RIGHT)
lastP2OutRight = p2OutRight = curP2Out;
}
else
{
curP2Out = 0;
if(APU_IO_Reg[0x25] & P2_ENABLE_LEFT)
p2OutLeft = 0;
if(APU_IO_Reg[0x25] & P2_ENABLE_RIGHT)
p2OutRight = 0;
//actually audible output
if(freq2 > 0 && freq2 < 0x7FF)
{
//GB/GBC Behavior
//p2Out = (curP2Out<<1)-15;
//GBA Behavior
p2Out = (curP2Out<<1)-p2Env.curVol;
}
}
else
curP2Out = 0;
if(APU_IO_Reg[0x25] & P2_ENABLE_LEFT)
p2OutLeft = p2Out;
if(APU_IO_Reg[0x25] & P2_ENABLE_RIGHT)
p2OutRight = p2Out;
if(wavenable && wavdacenable)
{
uint8_t v = APU_IO_Reg[0x30+(wavCycle>>1)];
curWavOut = APU_IO_Reg[0x30+(wavCycle>>1)];
if((wavCycle&1)==0)
v >>= 4;
curWavOut >>= 4;
else
v &= 0xF;
v>>=wavVolShift;
if(v && ((wavFreq > 0 && wavFreq < 0x7FF) || wavEqual))
{
curWavOut = v;
if(APU_IO_Reg[0x25] & WAV_ENABLE_LEFT)
lastWavOutLeft = wavOutLeft = curWavOut;
if(APU_IO_Reg[0x25] & WAV_ENABLE_RIGHT)
lastWavOutRight = wavOutRight = curWavOut;
}
else
{
curWavOut = 0;
if(APU_IO_Reg[0x25] & WAV_ENABLE_LEFT)
wavOutLeft = 0;
if(APU_IO_Reg[0x25] & WAV_ENABLE_RIGHT)
wavOutRight = 0;
}
curWavOut &= 0xF;
curWavOut >>= wavVolShift;
//actually audible output
if((wavFreq > 0 && wavFreq < 0x7FF) || wavEqual)
wavOut = (curWavOut<<1)-15;
}
else
curWavOut = 0;
if(APU_IO_Reg[0x25] & WAV_ENABLE_LEFT)
wavOutLeft = wavOut;
if(APU_IO_Reg[0x25] & WAV_ENABLE_RIGHT)
wavOutRight = wavOut;
if(noiseenable && noisedacenable)
{
if((noiseShiftReg&1) == 0 && noiseFreq > 0)
{
if((noiseShiftReg&1) == 0)
curNoiseOut = noiseEnv.curVol;
if(APU_IO_Reg[0x25] & NOISE_ENABLE_LEFT)
lastNoiseOutLeft = noiseOutLeft = curNoiseOut;
if(APU_IO_Reg[0x25] & NOISE_ENABLE_RIGHT)
lastNoiseOutRight = noiseOutRight = curNoiseOut;
}
else
{
curNoiseOut = 0;
if(APU_IO_Reg[0x25] & NOISE_ENABLE_LEFT)
noiseOutLeft = 0;
if(APU_IO_Reg[0x25] & NOISE_ENABLE_RIGHT)
noiseOutRight = 0;
//actually audible output
if(noiseFreq > 0)
{
//GB/GBC Behavior
//noiseOut = (curNoiseOut<<1)-15;
//GBA Behavior
noiseOut = (curNoiseOut<<1)-noiseEnv.curVol;
}
}
else
curNoiseOut = 0;
if(APU_IO_Reg[0x25] & NOISE_ENABLE_LEFT)
noiseOutLeft = noiseOut;
if(APU_IO_Reg[0x25] & NOISE_ENABLE_RIGHT)
noiseOutRight = noiseOut;
#if AUDIO_FLOAT
//gen output Left
float curInLeft = ((float)(p1OutLeft + p2OutLeft + wavOutLeft + noiseOutLeft))*volLevel[apuMasterVolLeft]/32.f;
float curInLeft = ((float)(p1OutLeft + p2OutLeft + wavOutLeft + noiseOutLeft))*volLevel[apuMasterVolLeft]/85.333333f;
float curLPOutLeft = lastLPOutLeft+(lpVal*(curInLeft-lastLPOutLeft));
float curHPOutLeft = hpVal*(lastHPOutLeft+lastLPOutLeft-curLPOutLeft);
//gen output Right
float curInRight = ((float)(p1OutRight + p2OutRight + wavOutRight + noiseOutRight))*volLevel[apuMasterVolRight]/32.f;
float curInRight = ((float)(p1OutRight + p2OutRight + wavOutRight + noiseOutRight))*volLevel[apuMasterVolRight]/85.333333f;
float curLPOutRight = lastLPOutRight+(lpVal*(curInRight-lastLPOutRight));
float curHPOutRight = hpVal*(lastHPOutRight+lastLPOutRight-curLPOutRight);
//set output Left
Expand All @@ -355,7 +352,7 @@ bool apuCycle()
#else
int32_t curIn, curOut;
//gen output Left
curIn = ((p1OutLeft + p2OutLeft + wavOutLeft + noiseOutLeft))*(apuMasterVolLeft+1)<<7;
curIn = (p1OutLeft + p2OutLeft + wavOutLeft + noiseOutLeft)*(apuMasterVolLeft+1)*48;
curOut = lastLPOutLeft+((lpVal*(curIn-lastLPOutLeft))>>15); //Set Left Lowpass Output
curIn = (lastHPOutLeft+lastLPOutLeft-curOut); //Set Left Highpass Input
curIn += (curIn>>31)&1; //Add Sign Bit for proper Downshift later
Expand All @@ -365,7 +362,7 @@ bool apuCycle()
//Save Clipped Left Highpass Output
apuOutBuf[curBufPos++] = ((soundEnabled)?((curOut > 32767)?(32767):((curOut < -32768)?(-32768):curOut)):0);
//gen output Right
curIn = ((p1OutRight + p2OutRight + wavOutRight + noiseOutRight))*(apuMasterVolRight+1)<<7;
curIn = (p1OutRight + p2OutRight + wavOutRight + noiseOutRight)*(apuMasterVolRight+1)*48;
curOut = lastLPOutRight+((lpVal*(curIn-lastLPOutRight))>>15); //Set Right Lowpass Output
curIn = (lastHPOutRight+lastLPOutRight-curOut); //Set Right Highpass Input
curIn += (curIn>>31)&1; //Add Sign Bit for proper Downshift later
Expand Down Expand Up @@ -567,10 +564,9 @@ void apuClockTimers()
if(noiseFreqCtr == 0)
{
noiseFreqCtr = noiseFreq;
uint8_t cmpBit = noiseMode1 ? (noiseShiftReg>>6)&1 : (noiseShiftReg>>1)&1;
uint8_t cmpRes = (noiseShiftReg&1)^cmpBit;
uint8_t cmpRes = (noiseShiftReg&1)^((noiseShiftReg>>1)&1);
noiseShiftReg >>= 1;
noiseShiftReg |= cmpRes<<14;
noiseShiftReg |= cmpRes << (noiseMode1 ? 6 : 14);
}
if(noiseFreqCtr)
noiseFreqCtr--;
Expand Down Expand Up @@ -657,8 +653,6 @@ void apuSetReg8(uint16_t addr, uint8_t val)
p1Env.curVol++;
p1Env.curVol &= 0xF;
}
else //Normal behaviour
p1Env.curVol = p1Env.vol;
p1dacenable = (p1Env.modeadd || p1Env.vol);
if(!p1dacenable)
p1enable = false;
Expand Down Expand Up @@ -731,8 +725,6 @@ void apuSetReg8(uint16_t addr, uint8_t val)
p2Env.curVol++;
p2Env.curVol &= 0xF;
}
else //Normal behaviour
p2Env.curVol = p2Env.vol;
p2dacenable = (p2Env.modeadd || p2Env.vol);
if(!p2dacenable)
p2enable = false;
Expand Down Expand Up @@ -855,8 +847,6 @@ void apuSetReg8(uint16_t addr, uint8_t val)
noiseEnv.curVol++;
noiseEnv.curVol &= 0xF;
}
else //Normal behaviour
noiseEnv.curVol = noiseEnv.vol;
noisedacenable = (noiseEnv.modeadd || noiseEnv.vol);
if(!noisedacenable)
noiseenable = false;
Expand Down Expand Up @@ -900,6 +890,8 @@ void apuSetReg8(uint16_t addr, uint8_t val)
noiseEnv.curVol = noiseEnv.vol;
//period 0 is actually period 8!
noiseEnv.divider = (noiseEnv.period-1)&7;
//trigger sets all shift reg bits
noiseShiftReg = 0x7FFF;
}
break;
default:
Expand Down
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