apu.cpp

SFC游戏模拟器 snes9x 1.43 的原代码

    case APU_P_LOW + 0x20:
    case APU_P_LOW + 0x30:
    case APU_P_LOW + 0x40:
    case APU_P_LOW + 0x50:
    case APU_P_LOW + 0x60:
    case APU_P_LOW + 0x70:
#ifdef DEBUGGER
		if (Settings.TraceSoundDSP)
			S9xTraceSoundDSP ("[%d] %d freq low: %d\n",
			ICPU.Scanline, reg>>4, byte);
#endif
		S9xSetSoundHertz (reg >> 4, ((byte + (APU.DSP [reg + 1] << 8)) & FREQUENCY_MASK) * 8);
		break;
		
    case APU_P_HIGH + 0x00:
    case APU_P_HIGH + 0x10:
    case APU_P_HIGH + 0x20:
    case APU_P_HIGH + 0x30:
    case APU_P_HIGH + 0x40:
    case APU_P_HIGH + 0x50:
    case APU_P_HIGH + 0x60:
    case APU_P_HIGH + 0x70:
#ifdef DEBUGGER
		if (Settings.TraceSoundDSP)
			S9xTraceSoundDSP ("[%d] %d freq high: %d\n",
			ICPU.Scanline, reg>>4, byte);
#endif
		S9xSetSoundHertz (reg >> 4, 
			(((byte << 8) + APU.DSP [reg - 1]) & FREQUENCY_MASK) * 8);
		break;
		
    case APU_SRCN + 0x00:
    case APU_SRCN + 0x10:
    case APU_SRCN + 0x20:
    case APU_SRCN + 0x30:
    case APU_SRCN + 0x40:
    case APU_SRCN + 0x50:
    case APU_SRCN + 0x60:
    case APU_SRCN + 0x70:
		if (byte != APU.DSP [reg])
		{
#ifdef DEBUGGER
			if (Settings.TraceSoundDSP)
				S9xTraceSoundDSP ("[%d] %d sample number: %d\n",
				ICPU.Scanline, reg>>4, byte);
#endif
			S9xSetSoundSample (reg >> 4, byte);
		}
		break;
		
    case APU_ADSR1 + 0x00:
    case APU_ADSR1 + 0x10:
    case APU_ADSR1 + 0x20:
    case APU_ADSR1 + 0x30:
    case APU_ADSR1 + 0x40:
    case APU_ADSR1 + 0x50:
    case APU_ADSR1 + 0x60:
    case APU_ADSR1 + 0x70:
		if (byte != APU.DSP [reg])
		{
#ifdef DEBUGGER
			if (Settings.TraceSoundDSP)
				S9xTraceSoundDSP ("[%d] %d adsr1: %02x\n",
				ICPU.Scanline, reg>>4, byte);
#endif
			{
				S9xFixEnvelope (reg >> 4, APU.DSP [reg + 2], byte, 
					APU.DSP [reg + 1]);
			}
		}
		break;
		
    case APU_ADSR2 + 0x00:
    case APU_ADSR2 + 0x10:
    case APU_ADSR2 + 0x20:
    case APU_ADSR2 + 0x30:
    case APU_ADSR2 + 0x40:
    case APU_ADSR2 + 0x50:
    case APU_ADSR2 + 0x60:
    case APU_ADSR2 + 0x70:
		if (byte != APU.DSP [reg])
		{
#ifdef DEBUGGER
			if (Settings.TraceSoundDSP)
				S9xTraceSoundDSP ("[%d] %d adsr2: %02x\n", 
				ICPU.Scanline, reg>>4, byte);
#endif
			{
				S9xFixEnvelope (reg >> 4, APU.DSP [reg + 1], APU.DSP [reg - 1],
					byte);
			}
		}
		break;
		
    case APU_GAIN + 0x00:
    case APU_GAIN + 0x10:
    case APU_GAIN + 0x20:
    case APU_GAIN + 0x30:
    case APU_GAIN + 0x40:
    case APU_GAIN + 0x50:
    case APU_GAIN + 0x60:
    case APU_GAIN + 0x70:
		if (byte != APU.DSP [reg])
		{
#ifdef DEBUGGER
			if (Settings.TraceSoundDSP)
				S9xTraceSoundDSP ("[%d] %d gain: %02x\n",
				ICPU.Scanline, reg>>4, byte);
#endif
			{
				S9xFixEnvelope (reg >> 4, byte, APU.DSP [reg - 2],
					APU.DSP [reg - 1]);
			}
		}
		break;
		
    case APU_ENVX + 0x00:
    case APU_ENVX + 0x10:
    case APU_ENVX + 0x20:
    case APU_ENVX + 0x30:
    case APU_ENVX + 0x40:
    case APU_ENVX + 0x50:
    case APU_ENVX + 0x60:
    case APU_ENVX + 0x70:
		break;
		
    case APU_OUTX + 0x00:
    case APU_OUTX + 0x10:
    case APU_OUTX + 0x20:
    case APU_OUTX + 0x30:
    case APU_OUTX + 0x40:
    case APU_OUTX + 0x50:
    case APU_OUTX + 0x60:
    case APU_OUTX + 0x70:
		break;
		
    case APU_DIR:
#ifdef DEBUGGER
		if (Settings.TraceSoundDSP)
			S9xTraceSoundDSP ("[%d] Sample directory to: %02x\n",
			ICPU.Scanline, byte);
#endif
		break;
		
    case APU_PMON:
		if (byte != APU.DSP [APU_PMON])
		{
#ifdef DEBUGGER
			if (Settings.TraceSoundDSP)
			{
				S9xTraceSoundDSP ("[%d] FreqMod:", ICPU.Scanline);
				uint8 mask = 1;
				for (int c = 0; c < 8; c++, mask <<= 1)
				{
					if (byte & mask)
					{
						if (APU.DSP [reg] & mask)
							S9xTraceSoundDSP ("%d", c);
						else
							S9xTraceSoundDSP ("%d(on),", c);
					}
					else
					{
						if (APU.DSP [reg] & mask)
							S9xTraceSoundDSP ("%d(off),", c);
					}
				}
				S9xTraceSoundDSP ("\n");
			}
#endif
			S9xSetFrequencyModulationEnable (byte);
		}
		break;
		
    case APU_EON:
		if (byte != APU.DSP [APU_EON])
		{
#ifdef DEBUGGER
			if (Settings.TraceSoundDSP)
			{
				S9xTraceSoundDSP ("[%d] Echo:", ICPU.Scanline);
				uint8 mask = 1;
				for (int c = 0; c < 8; c++, mask <<= 1)
				{
					if (byte & mask)
					{
						if (APU.DSP [reg] & mask)
							S9xTraceSoundDSP ("%d", c);
						else
							S9xTraceSoundDSP ("%d(on),", c);
					}
					else
					{
						if (APU.DSP [reg] & mask)
							S9xTraceSoundDSP ("%d(off),", c);
					}
				}
				S9xTraceSoundDSP ("\n");
			}
#endif
			S9xSetEchoEnable (byte);
		}
		break;
		
    case APU_EFB:
		S9xSetEchoFeedback ((signed char) byte);
		break;
		
    case APU_ESA:
		break;
		
    case APU_EDL:
		S9xSetEchoDelay (byte & 0xf);
		break;
		
    case APU_C0:
    case APU_C1:
    case APU_C2:
    case APU_C3:
    case APU_C4:
    case APU_C5:
    case APU_C6:
    case APU_C7:
		S9xSetFilterCoefficient (reg >> 4, (signed char) byte);
		break;
    default:
		// XXX
		//printf ("Write %02x to unknown APU register %02x\n", byte, reg);
		break;
    }
	
	KeyOnPrev|=KeyOn;
	KeyOn=0;
	
    if (reg < 0x80)
		APU.DSP [reg] = byte;
}

void S9xFixEnvelope (int channel, uint8 gain, uint8 adsr1, uint8 adsr2)
{
    if (adsr1 & 0x80)
    {
		// ADSR mode
		static unsigned long AttackRate [16] = {
			4100, 2600, 1500, 1000, 640, 380, 260, 160,
				96, 64, 40, 24, 16, 10, 6, 1
		};
		static unsigned long DecayRate [8] = {
			1200, 740, 440, 290, 180, 110, 74, 37
		};
		static unsigned long SustainRate [32] = {
			~0, 38000, 28000, 24000, 19000, 14000, 12000, 9400,
				7100, 5900, 4700, 3500, 2900, 2400, 1800, 1500,
				1200, 880, 740, 590, 440, 370, 290, 220,
				180, 150, 110, 92, 74, 55, 37, 18
		};
		// XXX: can DSP be switched to ADSR mode directly from GAIN/INCREASE/
		// DECREASE mode? And if so, what stage of the sequence does it start
		// at?
		if (S9xSetSoundMode (channel, MODE_ADSR))
		{
			// Hack for ROMs that use a very short attack rate, key on a 
			// channel, then switch to decay mode. e.g. Final Fantasy II.
			
			int attack = AttackRate [adsr1 & 0xf];
			
			if (attack == 1 && (!Settings.SoundSync
#ifdef __WIN32__
                || Settings.SoundDriver != WIN_SNES9X_DIRECT_SOUND_DRIVER
#endif
                ))
				attack = 0;
			
			S9xSetSoundADSR (channel, attack,
				DecayRate [(adsr1 >> 4) & 7],
				SustainRate [adsr2 & 0x1f],
				(adsr2 >> 5) & 7, 8);
		}
    }
    else
    {
		// Gain mode
		if ((gain & 0x80) == 0)
		{
			if (S9xSetSoundMode (channel, MODE_GAIN))
			{
				S9xSetEnvelopeRate (channel, 0, 0, gain & 0x7f);
				S9xSetEnvelopeHeight (channel, gain & 0x7f);
			}
		}
		else
		{
			static unsigned long IncreaseRate [32] = {
				~0, 4100, 3100, 2600, 2000, 1500, 1300, 1000,
					770, 640, 510, 380, 320, 260, 190, 160,
					130, 96, 80, 64, 48, 40, 32, 24,
					20, 16, 12, 10, 8, 6, 4, 2
			};
			static unsigned long DecreaseRateExp [32] = {
				~0, 38000, 28000, 24000, 19000, 14000, 12000, 9400,
					7100, 5900, 4700, 3500, 2900, 2400, 1800, 1500,
					1200, 880, 740, 590, 440, 370, 290, 220,
					180, 150, 110, 92, 74, 55, 37, 18
			};
			if (gain & 0x40)
			{
				// Increase mode
				if (S9xSetSoundMode (channel, (gain & 0x20) ?
MODE_INCREASE_BENT_LINE :
				MODE_INCREASE_LINEAR))
				{
					S9xSetEnvelopeRate (channel, IncreaseRate [gain & 0x1f],
						1, 127);
				}
			}
			else
			{
				uint32 rate = (gain & 0x20) ? DecreaseRateExp [gain & 0x1f] / 2 :
			IncreaseRate [gain & 0x1f];
			int mode = (gain & 0x20) ? MODE_DECREASE_EXPONENTIAL
				: MODE_DECREASE_LINEAR;
			
			if (S9xSetSoundMode (channel, mode))
				S9xSetEnvelopeRate (channel, rate, -1, 0);
			}
		}
    }
}

void S9xSetAPUControl (uint8 byte)
{
	//if (byte & 0x40)
	//printf ("*** Special SPC700 timing enabled\n");
    if ((byte & 1) != 0 && !APU.TimerEnabled [0])
    {
		APU.Timer [0] = 0;
		IAPU.RAM [0xfd] = 0;
		if ((APU.TimerTarget [0] = IAPU.RAM [0xfa]) == 0)
			APU.TimerTarget [0] = 0x100;
    }
    if ((byte & 2) != 0 && !APU.TimerEnabled [1])
    {
		APU.Timer [1] = 0;
		IAPU.RAM [0xfe] = 0;
		if ((APU.TimerTarget [1] = IAPU.RAM [0xfb]) == 0)
			APU.TimerTarget [1] = 0x100;
    }
    if ((byte & 4) != 0 && !APU.TimerEnabled [2])
    {
		APU.Timer [2] = 0;
		IAPU.RAM [0xff] = 0;
		if ((APU.TimerTarget [2] = IAPU.RAM [0xfc]) == 0)
			APU.TimerTarget [2] = 0x100;
    }
    APU.TimerEnabled [0] = byte & 1;
    APU.TimerEnabled [1] = (byte & 2) >> 1;
    APU.TimerEnabled [2] = (byte & 4) >> 2;
	
    if (byte & 0x10)
		IAPU.RAM [0xF4] = IAPU.RAM [0xF5] = 0;
	
    if (byte & 0x20)
		IAPU.RAM [0xF6] = IAPU.RAM [0xF7] = 0;
	
    if (byte & 0x80)
    {
		if (!APU.ShowROM)
		{
			memmove (&IAPU.RAM [0xffc0], APUROM, sizeof (APUROM));
			APU.ShowROM = TRUE;
		}
    }
    else
    {
		if (APU.ShowROM)
		{
			APU.ShowROM = FALSE;
			memmove (&IAPU.RAM [0xffc0], APU.ExtraRAM, sizeof (APUROM));
		}
    }
    IAPU.RAM [0xf1] = byte;
}

void S9xSetAPUTimer (uint16 Address, uint8 byte)
{
    IAPU.RAM [Address] = byte;
	
    switch (Address)
    {
    case 0xfa:
		if ((APU.TimerTarget [0] = IAPU.RAM [0xfa]) == 0)
			APU.TimerTarget [0] = 0x100;
		APU.TimerValueWritten [0] = TRUE;
		break;
    case 0xfb:
		if ((APU.TimerTarget [1] = IAPU.RAM [0xfb]) == 0)
			APU.TimerTarget [1] = 0x100;
		APU.TimerValueWritten [1] = TRUE;
		break;
    case 0xfc:
		if ((APU.TimerTarget [2] = IAPU.RAM [0xfc]) == 0)
			APU.TimerTarget [2] = 0x100;
		APU.TimerValueWritten [2] = TRUE;
		break;
    }
}

void S9xUpdateAPUTimer (void)
{
	while (CPU.Cycles * 10000L >= IAPU.NextAPUTimerPos)
	//if (CPU.Cycles * 10000L >= IAPU.NextAPUTimerPos)
	{
		//APU_EXECUTE();
		
		IAPU.NextAPUTimerPos += SNES_APUTIMER2_CYCLEx10000;		
		
		if (APU.TimerEnabled [2])
		{
			APU.Timer [2] ++;
			if (APU.Timer [2] >= APU.TimerTarget [2])
			{
			    IAPU.RAM [0xff] = (IAPU.RAM [0xff] + 1) & 0xf;
			    APU.Timer [2] = 0;
			#ifdef SPC700_SHUTDOWN		
			    IAPU.WaitCounter++;
			    IAPU.APUExecuting = TRUE;
			#endif		
			}
		}

		if (++IAPU.APUTimerCounter == 8)
		{
			IAPU.APUTimerCounter = 0;
			
			if (APU.TimerEnabled [0])
			{
			    APU.Timer [0]++;
			    if (APU.Timer [0] >= APU.TimerTarget [0])
			    {
					IAPU.RAM [0xfd] = (IAPU.RAM [0xfd] + 1) & 0xf;
					APU.Timer [0] = 0;
				#ifdef SPC700_SHUTDOWN		
					IAPU.WaitCounter++;
					IAPU.APUExecuting = TRUE;
				#endif		    
			    }
			}

			if (APU.TimerEnabled [1])
			{
			    APU.Timer [1]++;
			    if (APU.Timer [1] >= APU.TimerTarget [1])
			    {
					IAPU.RAM [0xfe] = (IAPU.RAM [0xfe] + 1) & 0xf;
					APU.Timer [1] = 0;
				#ifdef SPC700_SHUTDOWN		
					IAPU.WaitCounter++;
					IAPU.APUExecuting = TRUE;
				#endif		    
			    }
			}
		}
	}
}

uint8 S9xGetAPUDSP ()
{
    uint8 reg = IAPU.RAM [0xf2] & 0x7f;
    uint8 byte = APU.DSP [reg];
	
    switch (reg)
    {
    case APU_KON:
		break;
    case APU_KOFF:
		break;
    case APU_OUTX + 0x00:
    case APU_OUTX + 0x10:
    case APU_OUTX + 0x20:
    case APU_OUTX + 0x30:
    case APU_OUTX + 0x40:
    case APU_OUTX + 0x50:
    case APU_OUTX + 0x60:
    case APU_OUTX + 0x70:
		if (SoundData.channels [reg >> 4].state == SOUND_SILENT)
			return (0);
		return ((SoundData.channels [reg >> 4].sample >> 8) |
			(SoundData.channels [reg >> 4].sample & 0xff));
		
    case APU_ENVX + 0x00:
    case APU_ENVX + 0x10:
    case APU_ENVX + 0x20:
    case APU_ENVX + 0x30:
    case APU_ENVX + 0x40:
    case APU_ENVX + 0x50:
    case APU_ENVX + 0x60:
    case APU_ENVX + 0x70:
		return ((uint8) S9xGetEnvelopeHeight (reg >> 4));
		
    case APU_ENDX:
		// To fix speech in Magical Drop 2 6/11/00
		//	APU.DSP [APU_ENDX] = 0;
		break;
    default:
		break;
    }
    return (byte);
}