snapshot.cpp

著名SFC模拟器Snes9x的源代码。

    }

    delete block;
    return (result);
}

int UnfreezeBlock (STREAM stream, char *name, uint8 *block, int size)
{
    char buffer [20];
    int len = 0;
    int rem = 0;
    
    if (READ_STREAM (buffer, 11, stream) != 11 ||
	strncmp (buffer, name, 3) != 0 || buffer [3] != ':' ||
	(len = atoi (&buffer [4])) == 0)
    {
	return (WRONG_FORMAT);
    }

    if (len > size)
    {
	rem = len - size;
	len = size;
    }
    if (READ_STREAM (block, len, stream) != len)
	return (WRONG_FORMAT);

    if (rem)
    {
	char *junk = new char [rem];
	READ_STREAM (junk, rem, stream);
	delete junk;
    }
	
    return (SUCCESS);
}

bool8 S9xSPCDump (const char *filename)
{
    static uint8 header [] = {
	'S', 'N', 'E', 'S', '-', 'S', 'P', 'C', '7', '0', '0', ' ',
	'S', 'o', 'u', 'n', 'd', ' ', 'F', 'i', 'l', 'e', ' ',
	'D', 'a', 't', 'a', ' ', 'v', '0', '.', '3', '0', 26, 26, 26
    };
    static uint8 version = {
	0x1e
    };

    FILE *fs;

    S9xSetSoundMute (TRUE);

    if (!(fs = fopen (filename, "wb")))
	return (FALSE);

    // The SPC file format:
    // 0000: header:	'SNES-SPC700 Sound File Data v0.30',26,26,26
    // 0036: version:	$1e
    // 0037: SPC700 PC:
    // 0039: SPC700 A:
    // 0040: SPC700 X:
    // 0041: SPC700 Y:
    // 0042: SPC700 P:
    // 0043: SPC700 S:
    // 0044: Reserved: 0, 0, 0, 0
    // 0048: Title of game: 32 bytes
    // 0000: Song name: 32 bytes
    // 0000: Name of dumper: 32 bytes
    // 0000: Comments: 32 bytes
    // 0000: Date of SPC dump: 4 bytes
    // 0000: Fade out time in milliseconds: 4 bytes
    // 0000: Fade out length in milliseconds: 2 bytes
    // 0000: Default channel enables: 1 bytes
    // 0000: Emulator used to dump .SPC files: 1 byte, 1 == ZSNES
    // 0000: Reserved: 36 bytes
    // 0256: SPC700 RAM: 64K
    // ----: DSP Registers: 256 bytes

    if (fwrite (header, sizeof (header), 1, fs) != 1 ||
	fputc (version, fs) == EOF ||
	fseek (fs, 37, SEEK_SET) == EOF ||
	fputc (APURegisters.PC & 0xff, fs) == EOF ||
	fputc (APURegisters.PC >> 8, fs) == EOF ||
	fputc (APURegisters.YA.B.A, fs) == EOF ||
	fputc (APURegisters.X, fs) == EOF ||
	fputc (APURegisters.YA.B.Y, fs) == EOF ||
	fputc (APURegisters.P, fs) == EOF ||
	fputc (APURegisters.S, fs) == EOF ||
	fseek (fs, 256, SEEK_SET) == EOF ||
	fwrite (IAPU.RAM, 0x10000, 1, fs) != 1 ||
	fwrite (APU.DSP, 1, 256, fs) != 1 ||
	fwrite (APU.ExtraRAM, 64, 1, fs) != 1 ||
	fclose (fs) < 0)
    {
	S9xSetSoundMute (FALSE);
	return (FALSE);
    }
    S9xSetSoundMute (FALSE);
    return (TRUE);
}

bool8 S9xUnfreezeZSNES (const char *filename)
{
    FILE *fs;
    uint8 t [4000];

    if (!(fs = fopen (filename, "rb")))
	return (FALSE);

    if (fread (t, 64, 1, fs) == 1 &&
	strncmp ((char *) t, "ZSNES Save State File V0.6", 26) == 0)
    {
	S9xReset ();
	S9xSetSoundMute (TRUE);

	// 28 Curr cycle
	CPU.V_Counter = READ_WORD (&t [29]);
	// 33 instrset
	Settings.APUEnabled = t [36];

	// 34 bcycpl cycles per scanline
	// 35 cycphb cyclers per hblank

	Registers.A.W   = READ_WORD (&t [41]);
	Registers.DB    = t [43];
	Registers.PB    = t [44];
	Registers.S.W   = READ_WORD (&t [45]);
	Registers.D.W   = READ_WORD (&t [47]);
	Registers.X.W   = READ_WORD (&t [49]);
	Registers.Y.W   = READ_WORD (&t [51]);
	Registers.P.W   = READ_WORD (&t [53]);
	Registers.PC    = READ_WORD (&t [55]);

	fread (t, 1, 8, fs);
	fread (t, 1, 3019, fs);
	S9xSetCPU (t [2], 0x4200);
	Memory.FillRAM [0x4210] = t [3];
	PPU.IRQVBeamPos = READ_WORD (&t [4]);
	PPU.IRQHBeamPos = READ_WORD (&t [2527]);
	PPU.Brightness = t [6];
	PPU.ForcedBlanking = t [8] >> 7;

	int i;
	for (i = 0; i < 544; i++)
	    S9xSetPPU (t [0464 + i], 0x2104);

	PPU.OBJNameBase = READ_WORD (&t [9]);
	PPU.OBJNameSelect = READ_WORD (&t [13]) - PPU.OBJNameBase;
	switch (t [18])
	{
	case 4:
	    if (t [17] == 1)
		PPU.OBJSizeSelect = 0;
	    else
		PPU.OBJSizeSelect = 6;
	    break;
	case 16:
	    if (t [17] == 1)
		PPU.OBJSizeSelect = 1;
	    else
		PPU.OBJSizeSelect = 3;
	    break;
	default:
	case 64:
	    if (t [17] == 1)
		PPU.OBJSizeSelect = 2;
	    else
	    if (t [17] == 4)
		PPU.OBJSizeSelect = 4;
	    else
		PPU.OBJSizeSelect = 5;
	    break;
	}
	PPU.OAMAddr = READ_WORD (&t [25]);
	PPU.SavedOAMAddr =  READ_WORD (&t [27]);
	PPU.FirstSprite = t [29];
	PPU.BGMode = t [30];
	PPU.BG3Priority = t [31];
	PPU.BG[0].BGSize = (t [32] >> 0) & 1;
	PPU.BG[1].BGSize = (t [32] >> 1) & 1;
	PPU.BG[2].BGSize = (t [32] >> 2) & 1;
	PPU.BG[3].BGSize = (t [32] >> 3) & 1;
	PPU.Mosaic = t [33] + 1;
	PPU.BGMosaic [0] = (t [34] & 1) != 0;
	PPU.BGMosaic [1] = (t [34] & 2) != 0;
	PPU.BGMosaic [2] = (t [34] & 4) != 0;
	PPU.BGMosaic [3] = (t [34] & 8) != 0;
	PPU.BG [0].SCBase = READ_WORD (&t [35]) >> 1;
	PPU.BG [1].SCBase = READ_WORD (&t [37]) >> 1;
	PPU.BG [2].SCBase = READ_WORD (&t [39]) >> 1;
	PPU.BG [3].SCBase = READ_WORD (&t [41]) >> 1;
	PPU.BG [0].SCSize = t [67];
	PPU.BG [1].SCSize = t [68];
	PPU.BG [2].SCSize = t [69];
	PPU.BG [3].SCSize = t [70];
	PPU.BG[0].NameBase = READ_WORD (&t [71]) >> 1;
	PPU.BG[1].NameBase = READ_WORD (&t [73]) >> 1;
	PPU.BG[2].NameBase = READ_WORD (&t [75]) >> 1;
	PPU.BG[3].NameBase = READ_WORD (&t [77]) >> 1;
	PPU.BG[0].HOffset = READ_WORD (&t [79]);
	PPU.BG[1].HOffset = READ_WORD (&t [81]);
	PPU.BG[2].HOffset = READ_WORD (&t [83]);
	PPU.BG[3].HOffset = READ_WORD (&t [85]);
	PPU.BG[0].VOffset = READ_WORD (&t [89]);
	PPU.BG[1].VOffset = READ_WORD (&t [91]);
	PPU.BG[2].VOffset = READ_WORD (&t [93]);
	PPU.BG[3].VOffset = READ_WORD (&t [95]);
	PPU.VMA.Increment = READ_WORD (&t [97]) >> 1;
	PPU.VMA.High = t [99];
	IPPU.FirstVRAMRead = t [100];
	S9xSetPPU (t [2512], 0x2115);
	PPU.VMA.Address = READ_DWORD (&t [101]);
	for (i = 0; i < 512; i++)
	    S9xSetPPU (t [1488 + i], 0x2122);

	PPU.CGADD = (uint8) READ_WORD (&t [105]);
	Memory.FillRAM [0x212c] = t [108];
	Memory.FillRAM [0x212d] = t [109];
	PPU.ScreenHeight = READ_WORD (&t [111]);
	Memory.FillRAM [0x2133] = t [2526];
	Memory.FillRAM [0x4202] = t [113];
	Memory.FillRAM [0x4204] = t [114];
	Memory.FillRAM [0x4205] = t [115];
	Memory.FillRAM [0x4214] = t [116];
	Memory.FillRAM [0x4215] = t [117];
	Memory.FillRAM [0x4216] = t [118];
	Memory.FillRAM [0x4217] = t [119];
	PPU.VBeamPosLatched = READ_WORD (&t [122]);
	PPU.HBeamPosLatched = READ_WORD (&t [120]);
	PPU.Window1Left = t [127];
	PPU.Window1Right = t [128];
	PPU.Window2Left = t [129];
	PPU.Window2Right = t [130];
	S9xSetPPU (t [131] | (t [132] << 4), 0x2123);
	S9xSetPPU (t [133] | (t [134] << 4), 0x2124);
	S9xSetPPU (t [135] | (t [136] << 4), 0x2125);
	S9xSetPPU (t [137], 0x212a);
	S9xSetPPU (t [138], 0x212b);
	S9xSetPPU (t [139], 0x212e);
	S9xSetPPU (t [140], 0x212f);
	S9xSetPPU (t [141], 0x211a);
	PPU.MatrixA = READ_WORD (&t [142]);
	PPU.MatrixB = READ_WORD (&t [144]);
	PPU.MatrixC = READ_WORD (&t [146]);
	PPU.MatrixD = READ_WORD (&t [148]);
	PPU.CentreX = READ_WORD (&t [150]);
	PPU.CentreY = READ_WORD (&t [152]);
	// JoyAPos t[154]
	// JoyBPos t[155]
	Memory.FillRAM [2134] = t [156]; // Matrix mult
	Memory.FillRAM [2135] = t [157]; // Matrix mult
	Memory.FillRAM [2136] = t [158]; // Matrix mult
	PPU.WRAM = READ_DWORD (&t [161]);

	for (i = 0; i < 128; i++)
	    S9xSetCPU (t [165 + i], 0x4300 + i);

	if (t [294])
	    CPU.IRQActive |= PPU_V_BEAM_IRQ_SOURCE | PPU_H_BEAM_IRQ_SOURCE;

	S9xSetCPU (t [296], 0x420c);
	// hdmadata t[297] + 8 * 19
	PPU.FixedColourRed = t [450];
	PPU.FixedColourGreen = t [451];
	PPU.FixedColourBlue = t [452];
	S9xSetPPU (t [454], 0x2130);
	S9xSetPPU (t [455], 0x2131);
	// vraminctype ...

	fread (Memory.RAM, 1, 128 * 1024, fs);
	fread (Memory.VRAM, 1, 64 * 1024, fs);

	if (Settings.APUEnabled)
	{
	    // SNES SPC700 RAM (64K)
	    fread (IAPU.RAM, 1, 64 * 1024, fs);

	    // Junk 16 bytes
	    fread (t, 1, 16, fs);

	    // SNES SPC700 state and internal ZSNES SPC700 emulation state
	    fread (t, 1, 304, fs);

	    APURegisters.PC   = READ_DWORD (&t [0]);
	    APURegisters.YA.B.A = t [4];
	    APURegisters.X    = t [8];
	    APURegisters.YA.B.Y = t [12];
	    APURegisters.P    = t [16];
	    APURegisters.S    = t [24];
	    
	    APU.Cycles = READ_DWORD (&t [32]);
	    APU.ShowROM = (IAPU.RAM [0xf1] & 0x80) != 0;
	    APU.OutPorts [0] = t [36];
	    APU.OutPorts [1] = t [37];
	    APU.OutPorts [2] = t [38];
	    APU.OutPorts [3] = t [39];

	    APU.TimerEnabled [0] = (t [40] & 1) != 0;
	    APU.TimerEnabled [1] = (t [40] & 2) != 0;
	    APU.TimerEnabled [2] = (t [40] & 4) != 0;
	    S9xSetAPUTimer (0xfa, t [41]);
	    S9xSetAPUTimer (0xfb, t [42]);
	    S9xSetAPUTimer (0xfc, t [43]);
	    APU.Timer [0] = t [44];
	    APU.Timer [1] = t [45];
	    APU.Timer [2] = t [46];

	    memmove (APU.ExtraRAM, &t [48], 64);

	    // Internal ZSNES sound DSP state
	    fread (t, 1, 1068, fs);

	    // SNES sound DSP register values
	    fread (t, 1, 256, fs);
	    
	    uint8 saved = IAPU.RAM [0xf2];

	    for (i = 0; i < 128; i++)
	    {
		switch (i)
		{
		case APU_KON:
		case APU_KOFF:
		    break;
		case APU_FLG:
		    t [i] &= ~APU_SOFT_RESET;
		default:
		    IAPU.RAM [0xf2] = i;
		    S9xSetAPUDSP (t [i]);
		    break;
		}
	    }
	    IAPU.RAM [0xf2] = APU_KON;
	    S9xSetAPUDSP (t [APU_KON]);
	    IAPU.RAM [0xf2] = saved;

	    S9xSetSoundMute (FALSE);
	    IAPU.PC = IAPU.RAM + APURegisters.PC;
	    S9xAPUUnpackStatus ();
	    if (APUCheckDirectPage ())
		IAPU.DirectPage = IAPU.RAM + 0x100;
	    else
		IAPU.DirectPage = IAPU.RAM;
	    Settings.APUEnabled = TRUE;
	    IAPU.APUExecuting = TRUE;
	}
	else
	{
	    Settings.APUEnabled = FALSE;
	    IAPU.APUExecuting = FALSE;
	    S9xSetSoundMute (TRUE);
	}

	if (Settings.SuperFX)
	{
	    fread (::SRAM, 1, 64 * 1024, fs);
	    fseek (fs, 64 * 1024, SEEK_CUR);
	    fread (Memory.FillRAM + 0x7000, 1, 692, fs);
	}
	if (Settings.SA1)
	{
	    fread (t, 1, 2741, fs);
	    S9xSetSA1 (t [4], 0x2200);  // Control
	    S9xSetSA1 (t [12], 0x2203);	// ResetV low
	    S9xSetSA1 (t [13], 0x2204); // ResetV hi
	    S9xSetSA1 (t [14], 0x2205); // NMI low
	    S9xSetSA1 (t [15], 0x2206); // NMI hi
	    S9xSetSA1 (t [16], 0x2207); // IRQ low
	    S9xSetSA1 (t [17], 0x2208); // IRQ hi
	    S9xSetSA1 (((READ_DWORD (&t [28]) - (4096*1024-0x6000))) >> 13, 0x2224);
	    S9xSetSA1 (t [36], 0x2201);
	    S9xSetSA1 (t [41], 0x2209);

	    SA1Registers.A.W = READ_DWORD (&t [592]);
	    SA1Registers.X.W = READ_DWORD (&t [596]);
	    SA1Registers.Y.W = READ_DWORD (&t [600]);
	    SA1Registers.D.W = READ_DWORD (&t [604]);
	    SA1Registers.DB  = t [608];
	    SA1Registers.PB  = t [612];
	    SA1Registers.S.W = READ_DWORD (&t [616]);
	    SA1Registers.PC  = READ_DWORD (&t [636]);
	    SA1Registers.P.W = t [620] | (t [624] << 8);

	    memmove (&Memory.FillRAM [0x3000], t + 692, 2 * 1024);

	    fread (::SRAM, 1, 64 * 1024, fs);
	    fseek (fs, 64 * 1024, SEEK_CUR);
	    S9xFixSA1AfterSnapshotLoad ();
	}
	fclose (fs);

	Memory.FixROMSpeed ();
	IPPU.ColorsChanged = TRUE;
	IPPU.OBJChanged = TRUE;
	CPU.InDMA = FALSE;
	S9xFixColourBrightness ();
	IPPU.RenderThisFrame = FALSE;

	S9xFixSoundAfterSnapshotLoad ();
	ICPU.ShiftedPB = Registers.PB << 16;
	ICPU.ShiftedDB = Registers.DB << 16;
	S9xSetPCBase (ICPU.ShiftedPB + Registers.PC);
	S9xUnpackStatus ();
	S9xFixCycles ();
	S9xReschedule ();
#ifdef ZSNES_FX
	if (Settings.SuperFX)
	    S9xSuperFXPostLoadState ();
#endif
	return (TRUE);
    }
    fclose (fs);
    return (FALSE);
}