ppu.cpp

SFC游戏模拟器 snes9x 1.43 的原代码

					return;
				}
	}
	Memory.FillRAM[Address] = Byte;

}

/******************************************************************************/
/* S9xGetPPU()                                                                */
/* This function retrieves a PPU Register                                     */
/******************************************************************************/
uint8 S9xGetPPU (uint16 Address)
{
 	uint8 byte = OpenBus;

	if(Address<0x2100)//not a real PPU reg
		return OpenBus; //treat as unmapped memory returning last byte on the bus
    if (Address <= 0x2190)
    {
 	switch (Address)
  	{
  	case 0x2100:
  	case 0x2101:
  	case 0x2102:
    case 0x2103:
  #ifdef DEBUGGER
  	    missing.oam_address_read = 1;
  #endif
			return OpenBus;

	case 0x2104:
	case 0x2105:
	case 0x2106:
		return PPU.OpenBus1;
	case 0x2107:
		return OpenBus;
	case 0x2108:
	case 0x2109:
	case 0x210a:
		return PPU.OpenBus1;
	case 0x210b:
	case 0x210c:
	case 0x210d:
	case 0x210e:
	case 0x210f:
	case 0x2110:
	case 0x2111:
	case 0x2112:
	case 0x2113:
			missing.bg_offset_read = 1;
			return OpenBus;

	case 0x2114:
#ifdef DEBUGGER
	    missing.bg_offset_read = 1;
#endif
	case 0x2115:
	case 0x2116:
			return PPU.OpenBus1;

	case 0x2117:
			return OpenBus;

	case 0x2118:
	case 0x2119:
	case 0x211a:
			return PPU.OpenBus1;

	case 0x211b:
	case 0x211c:
	case 0x211d:
	case 0x211e:
	case 0x211f:
	case 0x2120:
#ifdef DEBUGGER
	    missing.matrix_read = 1;
#endif
			return OpenBus;

	case 0x2121:
	case 0x2122:
	case 0x2123:
			return OpenBus;

	case 0x2124:
	case 0x2125:
	case 0x2126:
			return PPU.OpenBus1;

	case 0x2127:
			return OpenBus;

	case 0x2128:
	case 0x2129:
	case 0x212a:
			return PPU.OpenBus1;

	case 0x212b:
	case 0x212c:
	case 0x212d:
	case 0x212e:
	case 0x212f:
	case 0x2130:
	case 0x2131:
	case 0x2132:
	case 0x2133:
			return OpenBus;

	case 0x2134:
	case 0x2135:
	case 0x2136:
	    // 16bit x 8bit multiply read result.
	    if (PPU.Need16x8Mulitply)
	    {
		int32 r = (int32) PPU.MatrixA * (int32) (PPU.MatrixB >> 8);

		Memory.FillRAM[0x2134] = (uint8) r;
		Memory.FillRAM[0x2135] = (uint8)(r >> 8);
		Memory.FillRAM[0x2136] = (uint8)(r >> 16);
		PPU.Need16x8Mulitply = FALSE;
	    }
#ifdef DEBUGGER
	    missing.matrix_multiply = 1;
#endif
		return (PPU.OpenBus1 = Memory.FillRAM[Address]);
	case 0x2137:
		S9xLatchCounters(0);
		return OpenBus;

	case 0x2138:
		// Read OAM (sprite) control data
		if(PPU.OAMAddr&0x100){
			if (!(PPU.OAMFlip&1))
			{
				byte = PPU.OAMData [(PPU.OAMAddr&0x10f) << 1];
			}
			else
			{
				byte = PPU.OAMData [((PPU.OAMAddr&0x10f) << 1) + 1];
				PPU.OAMAddr=(PPU.OAMAddr+1)&0x1ff;
				if (PPU.OAMPriorityRotation && PPU.FirstSprite != (PPU.OAMAddr >> 1))
				{
					PPU.FirstSprite = (PPU.OAMAddr&0xFE) >> 1;
					IPPU.OBJChanged = TRUE;
#ifdef DEBUGGER
					missing.sprite_priority_rotation = 1;
#endif
				}
			}
		} else {
			if (!(PPU.OAMFlip&1))
			{
				byte = PPU.OAMData [PPU.OAMAddr << 1];
			}
			else
			{
				byte = PPU.OAMData [(PPU.OAMAddr << 1) + 1];
				++PPU.OAMAddr;
				if (PPU.OAMPriorityRotation && PPU.FirstSprite != (PPU.OAMAddr >> 1))
				{
					PPU.FirstSprite = (PPU.OAMAddr&0xFE) >> 1;
					IPPU.OBJChanged = TRUE;
#ifdef DEBUGGER
					missing.sprite_priority_rotation = 1;
#endif
				}
			}
		}
		PPU.OAMFlip ^= 1;
#ifdef DEBUGGER
	    missing.oam_read = 1;
#endif
		return (PPU.OpenBus1 = byte);

	case 0x2139:
		// Read vram low byte
#ifdef DEBUGGER
		missing.vram_read = 1;
#endif
#ifdef CORRECT_VRAM_READS
		byte = IPPU.VRAMReadBuffer & 0xff;
		if (!PPU.VMA.High)
		{
			if (PPU.VMA.FullGraphicCount)
			{
				uint32 addr = PPU.VMA.Address;
				uint32 rem = addr & PPU.VMA.Mask1;
				uint32 address = (addr & ~PPU.VMA.Mask1) +
					(rem >> PPU.VMA.Shift) +
					((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
				IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM+((address << 1) & 0xFFFF));
			} else
				IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM+((PPU.VMA.Address << 1) & 0xffff));
			PPU.VMA.Address += PPU.VMA.Increment;
		}
#else
		if (IPPU.FirstVRAMRead)
			byte = Memory.VRAM[(PPU.VMA.Address << 1)&0xFFFF];
		else
			if (PPU.VMA.FullGraphicCount)
			{
				uint32 addr = PPU.VMA.Address - 1;
				uint32 rem = addr & PPU.VMA.Mask1;
				uint32 address = (addr & ~PPU.VMA.Mask1) +
					(rem >> PPU.VMA.Shift) +
					((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
				byte = Memory.VRAM [((address << 1) - 2) & 0xFFFF];
			}
			else
				byte = Memory.VRAM[((PPU.VMA.Address << 1) - 2) & 0xffff];
			
			if (!PPU.VMA.High)
			{
				PPU.VMA.Address += PPU.VMA.Increment;
				IPPU.FirstVRAMRead = FALSE;
			}
#endif
			PPU.OpenBus1 = byte;
			break;
	case 0x213A:
		// Read vram high byte
#ifdef DEBUGGER
		missing.vram_read = 1;
#endif
#ifdef CORRECT_VRAM_READS
		byte = (IPPU.VRAMReadBuffer>>8) & 0xff;
		if (PPU.VMA.High)
		{
			if (PPU.VMA.FullGraphicCount)
			{
				uint32 addr = PPU.VMA.Address;
				uint32 rem = addr & PPU.VMA.Mask1;
				uint32 address = (addr & ~PPU.VMA.Mask1) +
					(rem >> PPU.VMA.Shift) +
					((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
				IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM+((address << 1) & 0xFFFF));
			} else
				IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM+((PPU.VMA.Address << 1) & 0xffff));
			PPU.VMA.Address += PPU.VMA.Increment;
		}
#else
		if (IPPU.FirstVRAMRead)
			byte = Memory.VRAM[((PPU.VMA.Address << 1) + 1) & 0xffff];
		else
			if (PPU.VMA.FullGraphicCount)
			{
				uint32 addr = PPU.VMA.Address - 1;
				uint32 rem = addr & PPU.VMA.Mask1;
				uint32 address = (addr & ~PPU.VMA.Mask1) +
					(rem >> PPU.VMA.Shift) +
					((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
				byte = Memory.VRAM [((address << 1) - 1) & 0xFFFF];
			}
			else
				byte = Memory.VRAM[((PPU.VMA.Address << 1) - 1) & 0xFFFF];
			if (PPU.VMA.High)
			{
				PPU.VMA.Address += PPU.VMA.Increment;
				IPPU.FirstVRAMRead = FALSE;
			}
#endif
			PPU.OpenBus1 = byte;
			break;

	case 0x213B:
	    // Read palette data
#ifdef DEBUGGER
	    missing.cgram_read = 1;
#endif
	    if (PPU.CGFLIPRead)
		byte = PPU.CGDATA [PPU.CGADD++] >> 8;
	    else
		byte = PPU.CGDATA [PPU.CGADD] & 0xff;

	    PPU.CGFLIPRead ^= 1;
	    return (PPU.OpenBus2 = byte);
	    
	case 0x213C:
	    // Horizontal counter value 0-339
#ifdef DEBUGGER
	    missing.h_counter_read = 1;
#endif
	    if (PPU.HBeamFlip)
		byte = (PPU.OpenBus2 & 0xfe) | ((PPU.HBeamPosLatched >> 8) & 0x01);
	    else
		byte = (uint8)PPU.HBeamPosLatched;
            PPU.OpenBus2 = byte;
	    PPU.HBeamFlip ^= 1;
	    break;

	case 0x213D:
	    // Vertical counter value 0-262
#ifdef DEBUGGER
	    missing.v_counter_read = 1;
#endif
	    if (PPU.VBeamFlip)
                byte = (PPU.OpenBus2 & 0xfe) | ((PPU.VBeamPosLatched >> 8) & 0x01);
	    else
                byte = (uint8)PPU.VBeamPosLatched;
            PPU.OpenBus2 = byte;
	    PPU.VBeamFlip ^= 1;
	    break;

	case 0x213E:
	    // PPU time and range over flags
	    FLUSH_REDRAW ();

	    //so far, 5c77 version is always 1.
		return (PPU.OpenBus1 = (Model->_5C77 | PPU.RangeTimeOver));

	case 0x213F:
	    // NTSC/PAL and which field flags
	    PPU.VBeamFlip = PPU.HBeamFlip = 0;
            //neviksti found a 2 and a 3 here. SNEeSe uses a 3.
            //XXX: field flags not emulated
	    return ((Settings.PAL ? 0x10 : 0) | (Memory.FillRAM[0x213f] & 0xc0)| Model->_5C78) | (~PPU.OpenBus2 & 0x20);

	case 0x2140: case 0x2141: case 0x2142: case 0x2143:
	case 0x2144: case 0x2145: case 0x2146: case 0x2147:
	case 0x2148: case 0x2149: case 0x214a: case 0x214b:
	case 0x214c: case 0x214d: case 0x214e: case 0x214f:
	case 0x2150: case 0x2151: case 0x2152: case 0x2153:
	case 0x2154: case 0x2155: case 0x2156: case 0x2157:
	case 0x2158: case 0x2159: case 0x215a: case 0x215b:
	case 0x215c: case 0x215d: case 0x215e: case 0x215f:
	case 0x2160: case 0x2161: case 0x2162: case 0x2163:
	case 0x2164: case 0x2165: case 0x2166: case 0x2167:
	case 0x2168: case 0x2169: case 0x216a: case 0x216b:
	case 0x216c: case 0x216d: case 0x216e: case 0x216f:
	case 0x2170: case 0x2171: case 0x2172: case 0x2173:
	case 0x2174: case 0x2175: case 0x2176: case 0x2177:
	case 0x2178: case 0x2179: case 0x217a: case 0x217b:
	case 0x217c: case 0x217d: case 0x217e: case 0x217f:
#ifdef SPCTOOL
	    return ((uint8) _SPCOutP [Address & 3]);
#else
    //	CPU.Flags |= DEBUG_MODE_FLAG;
#ifdef SPC700_SHUTDOWN	
	    IAPU.APUExecuting = Settings.APUEnabled;
	    IAPU.WaitCounter++;
#endif
	    if (Settings.APUEnabled)
	    {
#ifdef CPU_SHUTDOWN
//		CPU.WaitAddress = CPU.PCAtOpcodeStart;
#endif	
		if (SNESGameFixes.APU_OutPorts_ReturnValueFix &&
		    Address >= 0x2140 && Address <= 0x2143 && !CPU.V_Counter)
		{
                    return (uint8)((Address & 1) ? ((rand() & 0xff00) >> 8) : 
				   (rand() & 0xff));
		}

		return (APU.OutPorts [Address & 3]);
	    }

	    switch (Settings.SoundSkipMethod)
	    {
	    case 0:
	    case 1:
		CPU.BranchSkip = TRUE;
		break;
	    case 2:
		break;
	    case 3:
		CPU.BranchSkip = TRUE;
		break;
	    }
	    if ((Address & 3) < 2)
	    {
		int r = rand ();
		if (r & 2)
		{
		    if (r & 4)
			return ((Address & 3) == 1 ? 0xaa : 0xbb);
		    else
			return ((r >> 3) & 0xff);
		}
	    }
	    else
	    {
		int r = rand ();
		if (r & 2)
		    return ((r >> 3) & 0xff);
	    }
	    return (Memory.FillRAM[Address]);
#endif // SPCTOOL

	case 0x2180:
	    // Read WRAM
#ifdef DEBUGGER
	    missing.wram_read = 1;
#endif
	    byte = Memory.RAM [PPU.WRAM++];
	    PPU.WRAM &= 0x1FFFF;
	    break;
	case 0x2181:
	case 0x2182:
	case 0x2183:
			return OpenBus;

		  default:
			return OpenBus;
	}
    }
    else
    {
	if (Settings.SA1)
	    return (S9xGetSA1 (Address));

	if (Address <= 0x2fff || Address >= 0x3000 + 768)
	{
	    switch (Address)
	    {
	    case 0x21c2:
			if(Model->_5C77 ==2)
		        return (0x20);

			//	fprintf(stderr, "Read from $21c2!\n");
				return OpenBus;
	    case 0x21c3:
				if(Model->_5C77 ==2)
			        return (0);
			//	fprintf(stderr, "Read from $21c3!\n");
				return OpenBus;
	    case 0x2800:
		// For Dai Kaijyu Monogatari II
		if (Settings.SRTC)
		    return (S9xGetSRTC (Address));
		/*FALL*/
			    
	    default:
#ifdef DEBUGGER
	        missing.unknownppu_read = Address;
	        if (Settings.TraceUnknownRegisters)
		{
		    sprintf (String, "Unknown register read: $%04X\n", Address);
		    S9xMessage (S9X_TRACE, S9X_PPU_TRACE, String);
		}
#endif
				return OpenBus;
	    }
	}
	
	if (!Settings.SuperFX)
			return OpenBus;
#ifdef ZSNES_FX
	if (Address < 0x3040)
	    byte = S9xSuperFXReadReg (Address);
	else
	    byte = Memory.FillRAM [Address];

#ifdef CPU_SHUTDOWN
	if (Address == 0x3030)
	    CPU.WaitAddress = CPU.PCAtOpcodeStart;
#endif	
	if (Address == 0x3031)
	    CLEAR_IRQ_SOURCE (GSU_IRQ_SOURCE);
#else
	byte = Memory.FillRAM [Address];

//if (Address != 0x3030 && Address != 0x3031)
//printf ("%04x\n", Address);
#ifdef CPU_SHUTDOWN
	if (Address == 0x3030)
	{
	    CPU.WaitAddress = CPU.PCAtOpcodeStart;
	}
	else
#endif
	if (Address == 0x3031)
	{
	    CLEAR_IRQ_SOURCE (GSU_IRQ_SOURCE);
	    Memory.FillRAM [0x3031] = byte & 0x7f;
	}
	return (byte);
#endif
    }
//    fprintf(stderr, "%03d: %02x from %04x\n", CPU.V_Counter, byte, Address);
    return (byte);
}

/******************************************************************************/
/* S9xSetCPU()                                                                */
/* This function sets a CPU/DMA Register to a specific byte                   */
/******************************************************************************/
void S9xSetCPU (uint8 byte, uint16 Address)
{
	int d;
//	fprintf(stderr, "%03d: %02x to %04x\n", CPU.V_Counter, byte, Address);

	if (Address < 0x4200)
	{
		CPU.Cycles += ONE_CYCLE;
		switch (Address)
		{
		  case 0x4016:
			// S9xReset reading of old-style joypads
			if ((byte & 1) && !(Memory.FillRAM [Address] & 1))
			{
				PPU.Joypad1ButtonReadPos = 0;
				PPU.Joypad2ButtonReadPos = 0;
				PPU.Joypad3ButtonReadPos = 0;
			}
			break;
		  case 0x4017:
			break;
		  default:
#ifdef DEBUGGER
			missing.unknowncpu_write = Address;
			if (Settings.TraceUnknownRegisters)
			{
				sprintf (String, "Unknown register register write: $%02X->$%04X\n",
						 byte, Address);
				S9xMessage (S9X_TRACE, S9X_PPU_TRACE, String);
			}
#endif
			break;
		}
	}
	else
		switch (Address)
		{
		  case 0x4200:
			// NMI, V & H IRQ and joypad reading enable flags
			if (byte & 0x20)
			{
				//if(!SNESGameFixes.umiharakawaseFix && PPU.IRQVBeamPos==262) fprintf(stderr, "PPU.IRQVBeamPos = %d, CPU.V_Counter = %d\n", PPU.IRQVBeamPos, CPU.V_Counter);
				if (!PPU.VTimerEnabled)
				{