dsp4emu.cpp

SFC游戏模拟器 snes9x 1.43 的原代码

/*******************************************************************************
  Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
 
  (c) Copyright 1996 - 2002 Gary Henderson ([e-mail]) and
                            Jerremy Koot ([e-mail])

  (c) Copyright 2001 - 2004 John Weidman ([e-mail])

  (c) Copyright 2002 - 2004 Brad Jorsch ([e-mail]),
                            funkyass ([e-mail]),
                            Joel Yliluoma (http://iki.fi/bisqwit/)
                            Kris Bleakley ([e-mail]),
                            Matthew Kendora,
                            Nach ([e-mail]),
                            Peter Bortas ([e-mail]) and
                            zones ([e-mail])

  C4 x86 assembler and some C emulation code
  (c) Copyright 2000 - 2003 zsKnight ([e-mail]),
                            _Demo_ ([e-mail]), and Nach

  C4 C++ code
  (c) Copyright 2003 Brad Jorsch

  DSP-1 emulator code
  (c) Copyright 1998 - 2004 Ivar ([e-mail]), _Demo_, Gary Henderson,
                            John Weidman, neviksti ([e-mail]),
                            Kris Bleakley, Andreas Naive

  DSP-2 emulator code
  (c) Copyright 2003 Kris Bleakley, John Weidman, neviksti, Matthew Kendora, and
                     Lord Nightmare ([e-mail]

  OBC1 emulator code
  (c) Copyright 2001 - 2004 zsKnight, pagefault ([e-mail]) and
                            Kris Bleakley
  Ported from x86 assembler to C by sanmaiwashi

  SPC7110 and RTC C++ emulator code
  (c) Copyright 2002 Matthew Kendora with research by
                     zsKnight, John Weidman, and Dark Force

  S-DD1 C emulator code
  (c) Copyright 2003 Brad Jorsch with research by
                     Andreas Naive and John Weidman
 
  S-RTC C emulator code
  (c) Copyright 2001 John Weidman
  
  ST010 C++ emulator code
  (c) Copyright 2003 Feather, Kris Bleakley, John Weidman and Matthew Kendora

  Super FX x86 assembler emulator code 
  (c) Copyright 1998 - 2003 zsKnight, _Demo_, and pagefault 

  Super FX C emulator code 
  (c) Copyright 1997 - 1999 Ivar, Gary Henderson and John Weidman


  SH assembler code partly based on x86 assembler code
  (c) Copyright 2002 - 2004 Marcus Comstedt ([e-mail]) 

 
  Specific ports contains the works of other authors. See headers in
  individual files.
 
  Snes9x homepage: http://www.snes9x.com
 
  Permission to use, copy, modify and distribute Snes9x in both binary and
  source form, for non-commercial purposes, is hereby granted without fee,
  providing that this license information and copyright notice appear with
  all copies and any derived work.
 
  This software is provided 'as-is', without any express or implied
  warranty. In no event shall the authors be held liable for any damages
  arising from the use of this software.
 
  Snes9x is freeware for PERSONAL USE only. Commercial users should
  seek permission of the copyright holders first. Commercial use includes
  charging money for Snes9x or software derived from Snes9x.
 
  The copyright holders request that bug fixes and improvements to the code
  should be forwarded to them so everyone can benefit from the modifications
  in future versions.
 
  Super NES and Super Nintendo Entertainment System are trademarks of
  Nintendo Co., Limited and its subsidiary companies.
*******************************************************************************/

// Due recognition and credit are given on Overload's DSP website.
// Thank those contributors for their hard work on this chip.

#include "dsp4.h"

#define DSP4_READ_WORD(x) \
	READ_WORD(DSP4.parameters+x)

#define DSP4_WRITE_WORD(x,d) \
	WRITE_WORD(DSP4.output+x,d);

// used to wait for dsp i/o
#define DSP4_WAIT(x) \
	DSP4_Logic = x; return;

//////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////

void DSP4_Multiply(short Multiplicand, short Multiplier, int &Product)
{
	Product = (Multiplicand * Multiplier << 1) >> 1;
}

void DSP4_UnknownOP11(short A, short B, short C, short D, short &M)
{
	// 0x155 = 341 = Horizontal Width of the Screen
	M = ((A * 0x0155 >>  2) & 0xf000) | ((B * 0x0155 >>  6) & 0x0f00) | 
	    ((C * 0x0155 >> 10) & 0x00f0) | ((D * 0x0155 >> 14) & 0x000f); 
}

const unsigned short Op0A_Values[16] = {
	0x0000, 0x0030, 0x0060, 0x0090, 0x00c0, 0x00f0, 0x0120, 0x0150,
	0xfe80, 0xfeb0, 0xfee0, 0xff10, 0xff40, 0xff70, 0xffa0, 0xffd0
};

void DSP4_Op0A(short n2, short &o1, short &o2, short &o3, short &o4)
{
	o4 = Op0A_Values[(n2 & 0x000f)];
	o3 = Op0A_Values[(n2 & 0x00f0) >> 4];
	o2 = Op0A_Values[(n2 & 0x0f00) >> 8];
	o1 = Op0A_Values[(n2 & 0xf000) >> 12];
}

//////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////

#if OP==0x0009
#define PRINT
#endif

void DSP4_Op03()
{
#ifdef PRINT
	printf("Op03\n");
#endif

	MaxTilesPerRow = 33;

	for (int i=0; i < 32; i++)
		RowCount[i] = 0;
	
	// reset op09 data
	op09_mode = 0;
}

void DSP4_Op0E()
{
#ifdef PRINT
	printf("Op0E\n");
#endif

	MaxTilesPerRow = 16;

	for (int i=0; i < 32; i++)
		RowCount[i] = 0;
	
	// reset op09 data
	op09_mode = 1;
}

#undef PRINT

void DSP4_Op06(bool8 size, bool8 msb)
{
	// save post-oam table data for future retrieval
	op06_OAM[op06_index] |= (msb<<(op06_offset+0));
	op06_OAM[op06_index] |= (size<<(op06_offset+1));
	op06_offset += 2;

	if(op06_offset==8)
	{
		// move to next byte in buffer
		op06_offset=0;
		op06_index++;
	}
}

#if OP==0x0001
#define PRINT
#endif

void DSP4_Op01()
{
	uint16 command;

	DSP4.waiting4command = FALSE;

	// op flow control
	switch(DSP4_Logic) {
		case 1: goto resume1; break;
		case 2: goto resume2; break;
	}

	////////////////////////////////////////////////////
	// process initial inputs

	// sort inputs
	// 0x00 = DSP4_READ_WORD(0x00);
	project_focaly = DSP4_READ_WORD(0x02);
	raster = DSP4_READ_WORD(0x04);
	viewport_top = DSP4_READ_WORD(0x06);
	project_y = DSP4_READ_WORD(0x08);
	viewport_bottom = DSP4_READ_WORD(0x0a);
	project_x1low = DSP4_READ_WORD(0x0c);
	project_focalx = DSP4_READ_WORD(0x0e);
	project_centerx = DSP4_READ_WORD(0x10);
	project_ptr = DSP4_READ_WORD(0x12);
	// (envelope?) 0xc0 = DSP4_READ_WORD(0x14);
	project_pitchylow = DSP4_READ_WORD(0x16);
	project_pitchy = DSP4_READ_WORD(0x18);
	project_pitchxlow = DSP4_READ_WORD(0x1a);
	project_pitchx = DSP4_READ_WORD(0x1c);
	far_plane = DSP4_READ_WORD(0x1e);
	// ? = DSP4_READ_WORD(0x20);
	project_y1low = DSP4_READ_WORD(0x22);

	// pre-compute
	view_plane = PLANE_START;

	// find starting projection points
	project_x1 = project_focalx;
	project_y -= viewport_bottom;

	// multi-op storage
	multi_index1 = 0;
	multi_index2 = 0;

	// debug
	block=0;

	////////////////////////////////////////////////////
	// command check

	do {
		// scan next command
		DSP4.in_count = 2;

		DSP4_WAIT(1) resume1:

		// inspect input
		command = DSP4_READ_WORD(0);

		// check for termination
		if(command == 0x8000) break;

		// already have 2 bytes in queue
		DSP4.in_index = 2;
		DSP4.in_count = 8;

		DSP4_WAIT(2) resume2:

		////////////////////////////////////////////////////
		// process one iteration of projection

		// inspect inputs
		int16 plane = DSP4_READ_WORD(0);
		int16 index, lcv;
		int16 py_dy=0, px_dx=0;
		int16 y_out, x_out;
		int16 envelope = DSP4_READ_WORD(6);
		int16 project_x;

		// ignore invalid data
		if((uint16) plane == 0x8001) continue;

		// one-time init
		if(far_plane)
		{
			// setup final parameters
			project_focalx += plane;
			project_x1 = project_focalx;
			project_y1 = project_focaly;
			plane = far_plane;
			far_plane = 0;

			// track occlusion
			multi_farplane[1] = plane;
			multi_raster[1] = viewport_bottom;
		}

		// use proportional triangles to project new coords
		project_x2 = project_focalx * plane / view_plane;
		project_y2 = project_focaly * plane / view_plane;

		// quadratic regression (rough)
		if(project_focaly>=-0x0f) 
			py_dy = project_focaly * project_focaly * -0.20533553
							- 1.08330005 * project_focaly - 69.61094639;
		else
			py_dy = project_focaly * project_focaly * -0.000657035759
							- 1.07629051 * project_focaly - 65.69315963;

		// approximate # of raster lines
		segments = abs(project_y2-project_y1);

		// prevent overdraw
		if(project_y2>=raster) segments=0;
		else raster=project_y2;

		// don't draw outside the window
		if(project_y2<viewport_top) segments=0;

		// project new positions
		if(segments>0)
		{
			// interpolate between projected points
			px_dx = ((project_x2-project_x1)<<8)/segments;
		}

		// debug
		++block;
#ifdef PRINT
		printf("(line %d) Op01 check %02X, plane %04X, focal_y %04X, y2 %04X, y1 %04X\n",c,(uint16)segments,(uint16)(plane),(uint16)project_focaly,(uint16)project_y2,(uint16)project_y1);
#endif

		// prepare output
		DSP4.out_count=8+2+6*segments;

		// pre-block data
		DSP4_WRITE_WORD(0,project_focalx);
		DSP4_WRITE_WORD(2,project_x2);
		DSP4_WRITE_WORD(4,project_focaly);
		DSP4_WRITE_WORD(6,project_y2);
		DSP4_WRITE_WORD(8,segments);
		
#if 0
		DSP4_WRITE_WORD(0,-1);
		DSP4_WRITE_WORD(2,-1);
		DSP4_WRITE_WORD(4,-1);
		DSP4_WRITE_WORD(6,-1);
		DSP4_WRITE_WORD(8,-1);
#endif

		index=10;

		project_x = project_centerx + project_x1;

		// iterate through each point
		for( lcv=0; lcv<segments; lcv++ )
		{
			// step through the projected line
			y_out = project_y+((py_dy*lcv)>>8);
			x_out = project_x+((px_dx*lcv)>>8);

			// factor in dynamic track changes
			y_out += envelope;

#if 0
			project_ptr=-1;
			y_out=-1;
			//x_out=-1;
#endif

			// data
			DSP4_WRITE_WORD(index+0,project_ptr);
			DSP4_WRITE_WORD(index+2,y_out);
			DSP4_WRITE_WORD(index+4,x_out);
			index += 6;

			// post-update
			project_ptr -= 4;
		}

		// post-update
		project_y += ((py_dy*lcv)>>8);

		// new positions
		if(segments>0)
		{
			project_x1 = project_x2;
			project_y1 = project_y2;

			// storage of focals for op07
			multi_focaly[multi_index2++] = project_focaly;

			// track occlusion: can't see anything below it
			multi_farplane[1] = plane;
			multi_raster[1] -= segments;
		}

		// update projection points
		project_pitchy += (int8)DSP4.parameters[3];
		project_pitchx += (int8)DSP4.parameters[5];

		project_focaly += project_pitchy;
		project_focalx += project_pitchx;
	} while (1);

	// terminate op
	DSP4.waiting4command = TRUE;
	DSP4.out_count = 0;
}

#undef PRINT

#if OP==0x0007
#define PRINT
#endif

void DSP4_Op07()
{
	uint16 command;

	DSP4.waiting4command = FALSE;

	// op flow control
	switch(DSP4_Logic) {
		case 1: goto resume1; break;
		case 2: goto resume2; break;
	}

	////////////////////////////////////////////////////
	// sort inputs

	// 0x00 = DSP4_READ_WORD(0x00);
	project_focaly = DSP4_READ_WORD(0x02);
	raster = DSP4_READ_WORD(0x04);
	viewport_top = DSP4_READ_WORD(0x06);
	project_y = DSP4_READ_WORD(0x08);
	viewport_bottom = DSP4_READ_WORD(0x0a);
	project_x1low = DSP4_READ_WORD(0x0c);
	project_x1 = DSP4_READ_WORD(0x0e);
	project_centerx = DSP4_READ_WORD(0x10);
	project_ptr = DSP4_READ_WORD(0x12);
	// (envelope?) 0xc0 = DSP4_READ_WORD(0x14);

	// pre-compute
	view_plane = PLANE_START;

	// find projection targets
	project_y1 = project_focaly;
	project_y -= viewport_bottom;

	// multi-op storage
	multi_index2 = 0;

	// debug
	block=0;

#ifdef PRINT
	printf("(line %d) Op07 data %04X\n",c,(uint16)project_y1);
#endif

	////////////////////////////////////////////////////
	// command check

	do {
		// scan next command
		DSP4.in_count = 2;

		DSP4_WAIT(1) resume1:

		// inspect input
		command = DSP4_READ_WORD(0);

		// check for opcode termination
		if(command == 0x8000) break;

			// already have 2 bytes in queue
		DSP4.in_index = 2;
		DSP4.in_count = 12;

		DSP4_WAIT(2) resume2:

		////////////////////////////////////////////////////
		// process one loop of projection

		int16 plane;
		int16 index,lcv;
		int16 y_out,x_out;
		int16 py_dy=0,px_dx=0;
		int16 project_x;

		// debug
		++block;

		// inspect inputs
		plane = DSP4_READ_WORD(0);
		project_y2 = DSP4_READ_WORD(2);
		// ? = DSP4_READ_WORD(4);
		project_x2 = DSP4_READ_WORD(6);
		int16 envelope = DSP4_READ_WORD(8);

		// ignore invalid data
		if((uint16) plane == 0x8001) continue;

		// multi-op storage
		project_focaly = multi_focaly[multi_index2];

		// quadratic regression (rough)
		if(project_focaly>=-0x0f) 
			py_dy = project_focaly * project_focaly * -0.20533553
							- 1.08330005 * project_focaly - 69.61094639;
		else
			py_dy = project_focaly * project_focaly * -0.000657035759
							- 1.07629051 * project_focaly - 65.69315963;

		// approximate # of raster lines
		segments = abs(project_y2-project_y1);

		// prevent overdraw
		if(project_y2>=raster) segments=0;
		else raster=project_y2;

		// don't draw outside the window
		if(project_y2<viewport_top) segments=0;

		// project new positions
		if(segments>0)
		{
			// interpolate between projected points
			px_dx = ((project_x2-project_x1)<<8)/segments;
		}

#ifdef PRINT
		printf("(line %d) Op07 block %d, loc %04X, out %02X, project_x2 %04X\n",c,block,plane,segments,(uint16)project_x2);
#endif

		// prepare pre-output
		DSP4.out_count=4+2+6*segments;