dsp1emu.c

SFC游戏模拟器 snes9x 1.43 的原代码

short Op04Radius;
short Op04Sin;
short Op04Cos;

const short DSP1_MulTable[256] = {
	  0x0000,  0x0003,  0x0006,  0x0009,  0x000c,  0x000f,  0x0012,  0x0015,
	  0x0019,  0x001c,  0x001f,  0x0022,  0x0025,  0x0028,  0x002b,  0x002f,
	  0x0032,  0x0035,  0x0038,  0x003b,  0x003e,  0x0041,  0x0045,  0x0048,
	  0x004b,  0x004e,  0x0051,  0x0054,  0x0057,  0x005b,  0x005e,  0x0061,
	  0x0064,  0x0067,  0x006a,  0x006d,  0x0071,  0x0074,  0x0077,  0x007a,
	  0x007d,  0x0080,  0x0083,  0x0087,  0x008a,  0x008d,  0x0090,  0x0093,
	  0x0096,  0x0099,  0x009d,  0x00a0,  0x00a3,  0x00a6,  0x00a9,  0x00ac,
	  0x00af,  0x00b3,  0x00b6,  0x00b9,  0x00bc,  0x00bf,  0x00c2,  0x00c5,
	  0x00c9,  0x00cc,  0x00cf,  0x00d2,  0x00d5,  0x00d8,  0x00db,  0x00df,
	  0x00e2,  0x00e5,  0x00e8,  0x00eb,  0x00ee,  0x00f1,  0x00f5,  0x00f8,
	  0x00fb,  0x00fe,  0x0101,  0x0104,  0x0107,  0x010b,  0x010e,  0x0111,
	  0x0114,  0x0117,  0x011a,  0x011d,  0x0121,  0x0124,  0x0127,  0x012a,
	  0x012d,  0x0130,  0x0133,  0x0137,  0x013a,  0x013d,  0x0140,  0x0143,
	  0x0146,  0x0149,  0x014d,  0x0150,  0x0153,  0x0156,  0x0159,  0x015c,
	  0x015f,  0x0163,  0x0166,  0x0169,  0x016c,  0x016f,  0x0172,  0x0175,
	  0x0178,  0x017c,  0x017f,  0x0182,  0x0185,  0x0188,  0x018b,  0x018e,
	  0x0192,  0x0195,  0x0198,  0x019b,  0x019e,  0x01a1,  0x01a4,  0x01a8,
	  0x01ab,  0x01ae,  0x01b1,  0x01b4,  0x01b7,  0x01ba,  0x01be,  0x01c1,
	  0x01c4,  0x01c7,  0x01ca,  0x01cd,  0x01d0,  0x01d4,  0x01d7,  0x01da,
	  0x01dd,  0x01e0,  0x01e3,  0x01e6,  0x01ea,  0x01ed,  0x01f0,  0x01f3,
	  0x01f6,  0x01f9,  0x01fc,  0x0200,  0x0203,  0x0206,  0x0209,  0x020c,
	  0x020f,  0x0212,  0x0216,  0x0219,  0x021c,  0x021f,  0x0222,  0x0225,
	  0x0228,  0x022c,  0x022f,  0x0232,  0x0235,  0x0238,  0x023b,  0x023e,
	  0x0242,  0x0245,  0x0248,  0x024b,  0x024e,  0x0251,  0x0254,  0x0258,
	  0x025b,  0x025e,  0x0261,  0x0264,  0x0267,  0x026a,  0x026e,  0x0271,
	  0x0274,  0x0277,  0x027a,  0x027d,  0x0280,  0x0284,  0x0287,  0x028a,
	  0x028d,  0x0290,  0x0293,  0x0296,  0x029a,  0x029d,  0x02a0,  0x02a3,
	  0x02a6,  0x02a9,  0x02ac,  0x02b0,  0x02b3,  0x02b6,  0x02b9,  0x02bc,
	  0x02bf,  0x02c2,  0x02c6,  0x02c9,  0x02cc,  0x02cf,  0x02d2,  0x02d5,
	  0x02d8,  0x02db,  0x02df,  0x02e2,  0x02e5,  0x02e8,  0x02eb,  0x02ee,
	  0x02f1,  0x02f5,  0x02f8,  0x02fb,  0x02fe,  0x0301,  0x0304,  0x0307,
	  0x030b,  0x030e,  0x0311,  0x0314,  0x0317,  0x031a,  0x031d,  0x0321};

const short DSP1_SinTable[256] = {
	  0x0000,  0x0324,  0x0647,  0x096a,  0x0c8b,  0x0fab,  0x12c8,  0x15e2,
	  0x18f8,  0x1c0b,  0x1f19,  0x2223,  0x2528,  0x2826,  0x2b1f,  0x2e11,
	  0x30fb,  0x33de,  0x36ba,  0x398c,  0x3c56,  0x3f17,  0x41ce,  0x447a,
	  0x471c,  0x49b4,  0x4c3f,  0x4ebf,  0x5133,  0x539b,  0x55f5,  0x5842,
	  0x5a82,  0x5cb4,  0x5ed7,  0x60ec,  0x62f2,  0x64e8,  0x66cf,  0x68a6,
	  0x6a6d,  0x6c24,  0x6dca,  0x6f5f,  0x70e2,  0x7255,  0x73b5,  0x7504,
	  0x7641,  0x776c,  0x7884,  0x798a,  0x7a7d,  0x7b5d,  0x7c29,  0x7ce3,
	  0x7d8a,  0x7e1d,  0x7e9d,  0x7f09,  0x7f62,  0x7fa7,  0x7fd8,  0x7ff6,
	  0x7fff,  0x7ff6,  0x7fd8,  0x7fa7,  0x7f62,  0x7f09,  0x7e9d,  0x7e1d,
	  0x7d8a,  0x7ce3,  0x7c29,  0x7b5d,  0x7a7d,  0x798a,  0x7884,  0x776c,
	  0x7641,  0x7504,  0x73b5,  0x7255,  0x70e2,  0x6f5f,  0x6dca,  0x6c24,
	  0x6a6d,  0x68a6,  0x66cf,  0x64e8,  0x62f2,  0x60ec,  0x5ed7,  0x5cb4,
	  0x5a82,  0x5842,  0x55f5,  0x539b,  0x5133,  0x4ebf,  0x4c3f,  0x49b4,
	  0x471c,  0x447a,  0x41ce,  0x3f17,  0x3c56,  0x398c,  0x36ba,  0x33de,
	  0x30fb,  0x2e11,  0x2b1f,  0x2826,  0x2528,  0x2223,  0x1f19,  0x1c0b,
	  0x18f8,  0x15e2,  0x12c8,  0x0fab,  0x0c8b,  0x096a,  0x0647,  0x0324,
	 -0x0000, -0x0324, -0x0647, -0x096a, -0x0c8b, -0x0fab, -0x12c8, -0x15e2,
	 -0x18f8, -0x1c0b, -0x1f19, -0x2223, -0x2528, -0x2826, -0x2b1f, -0x2e11,
	 -0x30fb, -0x33de, -0x36ba, -0x398c, -0x3c56, -0x3f17, -0x41ce, -0x447a,
	 -0x471c, -0x49b4, -0x4c3f, -0x4ebf, -0x5133, -0x539b, -0x55f5, -0x5842,
	 -0x5a82, -0x5cb4, -0x5ed7, -0x60ec, -0x62f2, -0x64e8, -0x66cf, -0x68a6,
	 -0x6a6d, -0x6c24, -0x6dca, -0x6f5f, -0x70e2, -0x7255, -0x73b5, -0x7504,
	 -0x7641, -0x776c, -0x7884, -0x798a, -0x7a7d, -0x7b5d, -0x7c29, -0x7ce3,
	 -0x7d8a, -0x7e1d, -0x7e9d, -0x7f09, -0x7f62, -0x7fa7, -0x7fd8, -0x7ff6,
	 -0x7fff, -0x7ff6, -0x7fd8, -0x7fa7, -0x7f62, -0x7f09, -0x7e9d, -0x7e1d,
	 -0x7d8a, -0x7ce3, -0x7c29, -0x7b5d, -0x7a7d, -0x798a, -0x7884, -0x776c,
	 -0x7641, -0x7504, -0x73b5, -0x7255, -0x70e2, -0x6f5f, -0x6dca, -0x6c24,
	 -0x6a6d, -0x68a6, -0x66cf, -0x64e8, -0x62f2, -0x60ec, -0x5ed7, -0x5cb4,
	 -0x5a82, -0x5842, -0x55f5, -0x539b, -0x5133, -0x4ebf, -0x4c3f, -0x49b4,
	 -0x471c, -0x447a, -0x41ce, -0x3f17, -0x3c56, -0x398c, -0x36ba, -0x33de,
	 -0x30fb, -0x2e11, -0x2b1f, -0x2826, -0x2528, -0x2223, -0x1f19, -0x1c0b,
	 -0x18f8, -0x15e2, -0x12c8, -0x0fab, -0x0c8b, -0x096a, -0x0647, -0x0324};

short DSP1_Sin(short Angle)
{
	if (Angle < 0) {
		if (Angle == -32768) return 0;
		return -DSP1_Sin(-Angle);
	}
	int S = DSP1_SinTable[Angle >> 8] + (DSP1_MulTable[Angle & 0xff] * DSP1_SinTable[0x40 + (Angle >> 8)] >> 15);
	if (S > 32767) S = 32767;
	return (short) S;
}

short DSP1_Cos(short Angle)
{
	if (Angle < 0) {
		if (Angle == -32768) return -32768;
		Angle = -Angle;
	}
	int S = DSP1_SinTable[0x40 + (Angle >> 8)] - (DSP1_MulTable[Angle & 0xff] * DSP1_SinTable[Angle >> 8] >> 15);
	if (S < -32768) S = -32767;
	return (short) S;
}

void DSP1_Normalize(short m, short *Coefficient, short *Exponent)
{
	short i = 0x4000;
	short e = 0;

	if (m < 0)
		while ((m & i) && i) {
			i >>= 1;
			e++;
		}
	else
		while (!(m & i) && i) {
			i >>= 1;
			e++;
		}

	if (e > 0)
		*Coefficient = m * DSP1ROM[0x21 + e] << 1;
	else
		*Coefficient = m;

	*Exponent -= e;
}

void DSP1_NormalizeDouble(int Product, short *Coefficient, short *Exponent)
{
	short n = Product & 0x7fff;
	short m = Product >> 15;
	short i = 0x4000;
	short e = 0;

	if (m < 0)
		while ((m & i) && i) {
			i >>= 1;
			e++;
		}
	else
		while (!(m & i) && i) {
			i >>= 1;
			e++;
		}

	if (e > 0)
	{
		*Coefficient = m * DSP1ROM[0x0021 + e] << 1;

		if (e < 15)
			*Coefficient += n * DSP1ROM[0x0040 - e] >> 15;
		else
		{
			i = 0x4000;

			if (m < 0)
				while ((n & i) && i) {
					i >>= 1;
					e++;
				}
			else
				while (!(n & i) && i) {
					i >>= 1;
					e++;
				}

			if (e > 15)
				*Coefficient = n * DSP1ROM[0x0012 + e] << 1;
			else
				*Coefficient += n;
		}
	}
	else
		*Coefficient = m;

	*Exponent = e;
}

short DSP1_Truncate(short C, short E)
{
	if (E > 0) {
		if (C > 0) return 32767; else if (C < 0) return -32767;
	} else {
		if (E < 0) return C * DSP1ROM[0x0031 + E] >> 15;
	}
	return C;
}

void DSPOp04()
{
	Op04Sin = DSP1_Sin(Op04Angle) * Op04Radius >> 15;
	Op04Cos = DSP1_Cos(Op04Angle) * Op04Radius >> 15;
}

short Op0CA;
short Op0CX1;
short Op0CY1;
short Op0CX2;
short Op0CY2;

void DSPOp0C()
{
	Op0CX2 = (Op0CY1 * DSP1_Sin(Op0CA) >> 15) + (Op0CX1 * DSP1_Cos(Op0CA) >> 15);
	Op0CY2 = (Op0CY1 * DSP1_Cos(Op0CA) >> 15) - (Op0CX1 * DSP1_Sin(Op0CA) >> 15);
}

short CentreX;
short CentreY;
short VOffset;

short VPlane_C;
short VPlane_E;

// Azimuth and Zenith angles
short SinAas;
short CosAas;
short SinAzs;
short CosAzs;

// Clipped Zenith angle
short SinAZS; 
short CosAZS;
short SecAZS_C1;
short SecAZS_E1;
short SecAZS_C2;
short SecAZS_E2;

const short MaxAZS_Exp[16] = {
	0x38b4, 0x38b7, 0x38ba, 0x38be, 0x38c0, 0x38c4, 0x38c7, 0x38ca, 
	0x38ce,	0x38d0, 0x38d4, 0x38d7, 0x38da, 0x38dd, 0x38e0, 0x38e4
};

void DSP1_Parameter(short Fx, short Fy, short Fz, short Lfe, short Les, short Aas, short Azs, short *Vof, short *Vva, short *Cx, short *Cy)
{
	short CSec, C, E;

	// Copy Zenith angle for clipping
	short AZS = Azs;

	// Store Sin and Cos of Azimuth and Zenith angles
	SinAas = DSP1_Sin(Aas);
	CosAas = DSP1_Cos(Aas);
	SinAzs = DSP1_Sin(Azs);
	CosAzs = DSP1_Cos(Azs);

	// Center of Projection
	CentreX = Fx + (Lfe * (SinAzs * -SinAas >> 15) >> 15);
	CentreY = Fy + (Lfe * (SinAzs * CosAas >> 15) >> 15);

	E = 0;
	DSP1_Normalize(Fz + (Lfe * (CosAzs * 0x7fff >> 15) >> 15), &C, &E);

	VPlane_C = C;
	VPlane_E = E;

	// Determine clip boundary and clip Zenith angle if necessary
	short MaxAZS = MaxAZS_Exp[-E];

	if (AZS < 0) {
		MaxAZS = -MaxAZS;
		if (AZS < MaxAZS + 1) AZS = MaxAZS + 1;
	} else {
		if (AZS > MaxAZS) AZS = MaxAZS;
	}

	// Store Sin and Cos of clipped Zenith angle
	SinAZS = DSP1_Sin(AZS);
	CosAZS = DSP1_Cos(AZS);

	DSP1_Inverse(CosAZS, 0, &SecAZS_C1, &SecAZS_E1);
	DSP1_Normalize(C * SecAZS_C1 >> 15, &C, &E);
	E += SecAZS_E1;

	C = DSP1_Truncate(C, E) * SinAZS >> 15;

	CentreX += C * SinAas >> 15;
	CentreY -= C * CosAas >> 15;

	*Cx = CentreX;
	*Cy = CentreY;

	// Raster number of imaginary center and horizontal line
	*Vof = 0;

	if ((Azs != AZS) || (Azs == MaxAZS)) 
	{
		if (Azs == -32768) Azs = -32767;

		C = Azs - MaxAZS;
		if (C >= 0) C--;
		short Aux = ~(C << 2);

		C = Aux * DSP1ROM[0x0328] >> 15;
		C = (C * Aux >> 15) + DSP1ROM[0x0327];
		*Vof -= (C * Aux >> 15) * Les >> 15;

		C = Aux * Aux >> 15;
		Aux = (C * DSP1ROM[0x0324] >> 15) + DSP1ROM[0x0325];
		CosAZS += (C * Aux >> 15) * CosAZS >> 15;
	}

	VOffset = Les * CosAZS >> 15;

	DSP1_Inverse(SinAZS, 0, &CSec, &E);
	DSP1_Normalize(VOffset, &C, &E);
	DSP1_Normalize(C * CSec >> 15, &C, &E);

	if (C == -32768) { C >>= 1; E++; }

	*Vva = DSP1_Truncate(-C, E);

	// Store Sec of clipped Zenith angle
	DSP1_Inverse(CosAZS, 0, &SecAZS_C2, &SecAZS_E2);
}

void DSP1_Raster(short Vs, short *An, short *Bn, short *Cn, short *Dn)
{
	short C, E, C1, E1;

	DSP1_Inverse((Vs * SinAzs >> 15) + VOffset, 7, &C, &E);
	E += VPlane_E;

	C1 = C * VPlane_C >> 15;
	E1 = E + SecAZS_E2;

	DSP1_Normalize(C1, &C, &E);

	C = DSP1_Truncate(C, E);

	*An = C * CosAas >> 15;
	*Cn = C * SinAas >> 15;

	DSP1_Normalize(C1 * SecAZS_C2 >> 15, &C, &E1);

	C = DSP1_Truncate(C, E1);

	*Bn = C * -SinAas >> 15;
	*Dn = C * CosAas >> 15;
}

short Op02FX;
short Op02FY;
short Op02FZ;
short Op02LFE;
short Op02LES;
short Op02AAS;
short Op02AZS;
short Op02VOF;
short Op02VVA;
short Op02CX;
short Op02CY;

void DSPOp02()
{
	DSP1_Parameter(Op02FX, Op02FY, Op02FZ, Op02LFE, Op02LES, Op02AAS, Op02AZS, &Op02VOF, &Op02VVA, &Op02CX, &Op02CY);
}

short Op0AVS;
short Op0AA;
short Op0AB;
short Op0AC;
short Op0AD;

void DSPOp0A()
{
	DSP1_Raster(Op0AVS, &Op0AA, &Op0AB, &Op0AC, &Op0AD);
	Op0AVS++;
}

short Op06X;
short Op06Y;
short Op06Z;
short Op06H;
short Op06V;
unsigned short Op06S;

double ObjPX;
double ObjPY;
double ObjPZ;
double ObjPX1;
double ObjPY1;
double ObjPZ1;
double ObjPX2;
double ObjPY2;
double ObjPZ2;
double DivideOp06;
int Temp;
int tanval2;

#ifdef __OPT06__
void DSPOp06()
{
   ObjPX=Op06X-Op02FX;
   ObjPY=Op06Y-Op02FY;
   ObjPZ=Op06Z-Op02FZ;

   // rotate around Z
   tanval2 = Angle(-Op02AAS+32768);
//   tanval2 = (-Op02AAS+32768)/(65536/INCR);
   ObjPX1=(ObjPX*Cos(tanval2)+ObjPY*-Sin(tanval2));
   ObjPY1=(ObjPX*Sin(tanval2)+ObjPY*Cos(tanval2));
   ObjPZ1=ObjPZ;

   // rotate around X
//   tanval2 = (-Op02AZS/(65536/INCR)) & 1023;
   tanval2 = Angle(-Op02AZS);
//   tanval2 = (-Op02AZS)/256;
   ObjPX2=ObjPX1;
   ObjPY2=(ObjPY1*Cos(tanval2)+ObjPZ1*-Sin(tanval2));
   ObjPZ2=(ObjPY1*Sin(tanval2)+ObjPZ1*Cos(tanval2));

   #ifdef debug06
   Log_Message("ObjPX2: %f ObjPY2: %f ObjPZ2: %f\n",ObjPX2,ObjPY2,ObjPZ2);
   #endif

   ObjPZ2=ObjPZ2-Op02LFE;

   if (ObjPZ2<0)
   {
      double d;
      Op06H=(short)(-ObjPX2*Op02LES/-(ObjPZ2)); //-ObjPX2*256/-ObjPZ2;
      Op06V=(short)(-ObjPY2*Op02LES/-(ObjPZ2)); //-ObjPY2*256/-ObjPZ2;
      d=(double)Op02LES;
	  d*=256.0;
	  d/=(-ObjPZ2);
	  if(d>65535.0)
		  d=65535.0;
	  else if(d<0.0)
		  d=0.0;
	  Op06S=(unsigned short)d;
	  //Op06S=(unsigned short)(256*(double)Op02LES/-ObjPZ2);
      //Op06S=(unsigned short)((double)(256.0*((double)Op02LES)/(-ObjPZ2)));
   }
   else
   {
      Op06H=0;
      Op06V=14*16;
      Op06S=0xFFFF;
   }


   #ifdef DebugDSP1
      Log_Message("OP06 X:%d Y:%d Z:%d",Op06X,Op06Y,Op06Z);
      Log_Message("OP06 H:%d V:%d S:%d",Op06H,Op06V,Op06S);
   #endif
}
#else

void DSPOp06()
{
   ObjPX=Op06X-Op02FX;
   ObjPY=Op06Y-Op02FY;
   ObjPZ=Op06Z-Op02FZ;

   // rotate around Z
   tanval = (-Op02AAS+32768)/65536.0*6.2832;
   ObjPX1=(ObjPX*cos(tanval)+ObjPY*-sin(tanval));
   ObjPY1=(ObjPX*sin(tanval)+ObjPY*cos(tanval));
   ObjPZ1=ObjPZ;

   #ifdef debug06
   Log_Message("Angle : %f", tanval);
   Log_Message("ObjPX1: %f ObjPY1: %f ObjPZ1: %f\n",ObjPX1,ObjPY1,ObjPZ1);
   Log_Message("cos(tanval) : %f  sin(tanval) : %f", cos(tanval), sin(tanval));
   #endif

   // rotate around X
   tanval = (-Op02AZS)/65536.0*6.2832;
   ObjPX2=ObjPX1;
   ObjPY2=(ObjPY1*cos(tanval)+ObjPZ1*-sin(tanval));
   ObjPZ2=(ObjPY1*sin(tanval)+ObjPZ1*cos(tanval));

   #ifdef debug06
   Log_Message("ObjPX2: %f ObjPY2: %f ObjPZ2: %f\n",ObjPX2,ObjPY2,ObjPZ2);
   #endif