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snes9xgx/source/snes9x/dsp4.cpp

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initial port of snes9x 1.52 beta
2009-11-25 07:35:14 +01:00
/**********************************************************************************
Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
(c) Copyright 1996 - 2002 Gary Henderson (gary.henderson@ntlworld.com),
Jerremy Koot (jkoot@snes9x.com)
(c) Copyright 2002 - 2004 Matthew Kendora
(c) Copyright 2002 - 2005 Peter Bortas (peter@bortas.org)
(c) Copyright 2004 - 2005 Joel Yliluoma (http://iki.fi/bisqwit/)
(c) Copyright 2001 - 2006 John Weidman (jweidman@slip.net)
(c) Copyright 2002 - 2006 funkyass (funkyass@spam.shaw.ca),
Kris Bleakley (codeviolation@hotmail.com)
(c) Copyright 2002 - 2007 Brad Jorsch (anomie@users.sourceforge.net),
Nach (n-a-c-h@users.sourceforge.net),
zones (kasumitokoduck@yahoo.com)
(c) Copyright 2006 - 2007 nitsuja
BS-X C emulator code
(c) Copyright 2005 - 2006 Dreamer Nom,
zones
C4 x86 assembler and some C emulation code
(c) Copyright 2000 - 2003 _Demo_ (_demo_@zsnes.com),
Nach,
zsKnight (zsknight@zsnes.com)
C4 C++ code
(c) Copyright 2003 - 2006 Brad Jorsch,
Nach
DSP-1 emulator code
(c) Copyright 1998 - 2006 _Demo_,
Andreas Naive (andreasnaive@gmail.com)
Gary Henderson,
Ivar (ivar@snes9x.com),
John Weidman,
Kris Bleakley,
Matthew Kendora,
Nach,
neviksti (neviksti@hotmail.com)
DSP-2 emulator code
(c) Copyright 2003 John Weidman,
Kris Bleakley,
Lord Nightmare (lord_nightmare@users.sourceforge.net),
Matthew Kendora,
neviksti
DSP-3 emulator code
(c) Copyright 2003 - 2006 John Weidman,
Kris Bleakley,
Lancer,
z80 gaiden
DSP-4 emulator code
(c) Copyright 2004 - 2006 Dreamer Nom,
John Weidman,
Kris Bleakley,
Nach,
z80 gaiden
OBC1 emulator code
(c) Copyright 2001 - 2004 zsKnight,
pagefault (pagefault@zsnes.com),
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,
Dark Force
S-DD1 C emulator code
(c) Copyright 2003 Brad Jorsch with research by
Andreas Naive,
John Weidman
S-RTC C emulator code
(c) Copyright 2001-2006 byuu,
John Weidman
ST010 C++ emulator code
(c) Copyright 2003 Feather,
John Weidman,
Kris Bleakley,
Matthew Kendora
Super FX x86 assembler emulator code
(c) Copyright 1998 - 2003 _Demo_,
pagefault,
zsKnight,
Super FX C emulator code
(c) Copyright 1997 - 1999 Ivar,
Gary Henderson,
John Weidman
Sound DSP emulator code is derived from SNEeSe and OpenSPC:
(c) Copyright 1998 - 2003 Brad Martin
(c) Copyright 1998 - 2006 Charles Bilyue'
SH assembler code partly based on x86 assembler code
(c) Copyright 2002 - 2004 Marcus Comstedt (marcus@mc.pp.se)
2xSaI filter
(c) Copyright 1999 - 2001 Derek Liauw Kie Fa
HQ2x, HQ3x, HQ4x filters
(c) Copyright 2003 Maxim Stepin (maxim@hiend3d.com)
Win32 GUI code
(c) Copyright 2003 - 2006 blip,
funkyass,
Matthew Kendora,
Nach,
nitsuja
Mac OS GUI code
(c) Copyright 1998 - 2001 John Stiles
(c) Copyright 2001 - 2007 zones
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/or 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 or it's derivatives.
Snes9x is freeware for PERSONAL USE only. Commercial users should
seek permission of the copyright holders first. Commercial use includes,
but is not limited to, charging money for Snes9x or software derived from
Snes9x, including Snes9x or derivatives in commercial game bundles, and/or
using Snes9x as a promotion for your commercial product.
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.
Fixed-point math reminder:
[sign, integer, fraction]
1.15.00 * 1.15.00 = 2.30.00 -> 1.30.00 (DSP) -> 1.31.00 (LSB is '0')
1.15.00 * 1.00.15 = 2.15.15 -> 1.15.15 (DSP) -> 1.15.16 (LSB is '0')
*/
#include "snes9x.h"
#include "memmap.h"
#define DSP4_CLEAR_OUT() \
{ DSP4.out_count = 0; DSP4.out_index = 0; }
#define DSP4_WRITE_BYTE(d) \
{ WRITE_WORD(DSP4.output + DSP4.out_count, (d)); DSP4.out_count++; }
#define DSP4_WRITE_WORD(d) \
{ WRITE_WORD(DSP4.output + DSP4.out_count, (d)); DSP4.out_count += 2; }
#ifndef MSB_FIRST
#define DSP4_WRITE_16_WORD(d) \
{ memcpy(DSP4.output + DSP4.out_count, (d), 32); DSP4.out_count += 32; }
#else
#define DSP4_WRITE_16_WORD(d) \
{ for (int p = 0; p < 16; p++) DSP4_WRITE_WORD((d)[p]); }
#endif
// used to wait for dsp i/o
#define DSP4_WAIT(x) \
DSP4.in_index = 0; DSP4.Logic = (x); return
// 1.7.8 -> 1.15.16
#define SEX78(a) (((int32) ((int16) (a))) << 8)
// 1.15.0 -> 1.15.16
#define SEX16(a) (((int32) ((int16) (a))) << 16)
static int16 DSP4_READ_WORD (void);
static int32 DSP4_READ_DWORD (void);
static int16 DSP4_Inverse (int16);
static void DSP4_Multiply (int16, int16, int32 *);
static void DSP4_OP01 (void);
static void DSP4_OP03 (void);
static void DSP4_OP05 (void);
static void DSP4_OP06 (void);
static void DSP4_OP07 (void);
static void DSP4_OP08 (void);
static void DSP4_OP09 (void);
static void DSP4_OP0A (int16, int16 *, int16 *, int16 *, int16 *);
static void DSP4_OP0B (bool8 *, int16, int16, int16, bool8, bool8);
static void DSP4_OP0D (void);
static void DSP4_OP0E (void);
static void DSP4_OP0F (void);
static void DSP4_OP10 (void);
static void DSP4_OP11 (int16, int16, int16, int16, int16 *);
static void DSP4_SetByte (void);
static void DSP4_GetByte (void);
static int16 DSP4_READ_WORD (void)
{
int16 out;
out = READ_WORD(DSP4.parameters + DSP4.in_index);
DSP4.in_index += 2;
return (out);
}
static int32 DSP4_READ_DWORD (void)
{
int32 out;
out = READ_DWORD(DSP4.parameters + DSP4.in_index);
DSP4.in_index += 4;
return (out);
}
static int16 DSP4_Inverse (int16 value)
{
// Attention: This lookup table is not verified
const uint16 div_lut[64] =
{
0x0000, 0x8000, 0x4000, 0x2aaa, 0x2000, 0x1999, 0x1555, 0x1249,
0x1000, 0x0e38, 0x0ccc, 0x0ba2, 0x0aaa, 0x09d8, 0x0924, 0x0888,
0x0800, 0x0787, 0x071c, 0x06bc, 0x0666, 0x0618, 0x05d1, 0x0590,
0x0555, 0x051e, 0x04ec, 0x04bd, 0x0492, 0x0469, 0x0444, 0x0421,
0x0400, 0x03e0, 0x03c3, 0x03a8, 0x038e, 0x0375, 0x035e, 0x0348,
0x0333, 0x031f, 0x030c, 0x02fa, 0x02e8, 0x02d8, 0x02c8, 0x02b9,
0x02aa, 0x029c, 0x028f, 0x0282, 0x0276, 0x026a, 0x025e, 0x0253,
0x0249, 0x023e, 0x0234, 0x022b, 0x0222, 0x0219, 0x0210, 0x0208
};
// saturate bounds
if (value < 0)
value = 0;
if (value > 63)
value = 63;
return (div_lut[value]);
}
static void DSP4_Multiply (int16 Multiplicand, int16 Multiplier, int32 *Product)
{
*Product = (Multiplicand * Multiplier << 1) >> 1;
}
static void DSP4_OP01 (void)
{
DSP4.waiting4command = FALSE;
// op flow control
switch (DSP4.Logic)
{
case 1: goto resume1; break;
case 2: goto resume2; break;
case 3: goto resume3; break;
}
////////////////////////////////////////////////////
// process initial inputs
// sort inputs
DSP4.world_y = DSP4_READ_DWORD();
DSP4.poly_bottom[0][0] = DSP4_READ_WORD();
DSP4.poly_top[0][0] = DSP4_READ_WORD();
DSP4.poly_cx[1][0] = DSP4_READ_WORD();
DSP4.viewport_bottom = DSP4_READ_WORD();
DSP4.world_x = DSP4_READ_DWORD();
DSP4.poly_cx[0][0] = DSP4_READ_WORD();
DSP4.poly_ptr[0][0] = DSP4_READ_WORD();
DSP4.world_yofs = DSP4_READ_WORD();
DSP4.world_dy = DSP4_READ_DWORD();
DSP4.world_dx = DSP4_READ_DWORD();
DSP4.distance = DSP4_READ_WORD();
DSP4_READ_WORD(); // 0x0000
DSP4.world_xenv = DSP4_READ_DWORD();
DSP4.world_ddy = DSP4_READ_WORD();
DSP4.world_ddx = DSP4_READ_WORD();
DSP4.view_yofsenv = DSP4_READ_WORD();
// initial (x, y, offset) at starting raster line
DSP4.view_x1 = (DSP4.world_x + DSP4.world_xenv) >> 16;
DSP4.view_y1 = DSP4.world_y >> 16;
DSP4.view_xofs1 = DSP4.world_x >> 16;
DSP4.view_yofs1 = DSP4.world_yofs;
DSP4.view_turnoff_x = 0;
DSP4.view_turnoff_dx = 0;
// first raster line
DSP4.poly_raster[0][0] = DSP4.poly_bottom[0][0];
do
{
////////////////////////////////////////////////////
// process one iteration of projection
// perspective projection of world (x, y, scroll) points
// based on the current projection lines
DSP4.view_x2 = (((DSP4.world_x + DSP4.world_xenv) >> 16) * DSP4.distance >> 15) + (DSP4.view_turnoff_x * DSP4.distance >> 15);
DSP4.view_y2 = (DSP4.world_y >> 16) * DSP4.distance >> 15;
DSP4.view_xofs2 = DSP4.view_x2;
DSP4.view_yofs2 = (DSP4.world_yofs * DSP4.distance >> 15) + DSP4.poly_bottom[0][0] - DSP4.view_y2;
// 1. World x-location before transformation
// 2. Viewer x-position at the next
// 3. World y-location before perspective projection
// 4. Viewer y-position below the horizon
// 5. Number of raster lines drawn in this iteration
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD((DSP4.world_x + DSP4.world_xenv) >> 16);
DSP4_WRITE_WORD(DSP4.view_x2);
DSP4_WRITE_WORD(DSP4.world_y >> 16);
DSP4_WRITE_WORD(DSP4.view_y2);
//////////////////////////////////////////////////////
// SR = 0x00
// determine # of raster lines used
DSP4.segments = DSP4.poly_raster[0][0] - DSP4.view_y2;
// prevent overdraw
if (DSP4.view_y2 >= DSP4.poly_raster[0][0])
DSP4.segments = 0;
else
DSP4.poly_raster[0][0] = DSP4.view_y2;
// don't draw outside the window
if (DSP4.view_y2 < DSP4.poly_top[0][0])
{
DSP4.segments = 0;
// flush remaining raster lines
if (DSP4.view_y1 >= DSP4.poly_top[0][0])
DSP4.segments = DSP4.view_y1 - DSP4.poly_top[0][0];
}
// SR = 0x80
DSP4_WRITE_WORD(DSP4.segments);
//////////////////////////////////////////////////////
// scan next command if no SR check needed
if (DSP4.segments)
{
int32 px_dx, py_dy;
int32 x_scroll, y_scroll;
// SR = 0x00
// linear interpolation (lerp) between projected points
px_dx = (DSP4.view_xofs2 - DSP4.view_xofs1) * DSP4_Inverse(DSP4.segments) << 1;
py_dy = (DSP4.view_yofs2 - DSP4.view_yofs1) * DSP4_Inverse(DSP4.segments) << 1;
// starting step values
x_scroll = SEX16(DSP4.poly_cx[0][0] + DSP4.view_xofs1);
y_scroll = SEX16(-DSP4.viewport_bottom + DSP4.view_yofs1 + DSP4.view_yofsenv + DSP4.poly_cx[1][0] - DSP4.world_yofs);
// SR = 0x80
// rasterize line
for (DSP4.lcv = 0; DSP4.lcv < DSP4.segments; DSP4.lcv++)
{
// 1. HDMA memory pointer (bg1)
// 2. vertical scroll offset ($210E)
// 3. horizontal scroll offset ($210D)
DSP4_WRITE_WORD(DSP4.poly_ptr[0][0]);
DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16);
DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16);
// update memory address
DSP4.poly_ptr[0][0] -= 4;
// update screen values
x_scroll += px_dx;
y_scroll += py_dy;
}
}
////////////////////////////////////////////////////
// Post-update
// update new viewer (x, y, scroll) to last raster line drawn
DSP4.view_x1 = DSP4.view_x2;
DSP4.view_y1 = DSP4.view_y2;
DSP4.view_xofs1 = DSP4.view_xofs2;
DSP4.view_yofs1 = DSP4.view_yofs2;
// add deltas for projection lines
DSP4.world_dx += SEX78(DSP4.world_ddx);
DSP4.world_dy += SEX78(DSP4.world_ddy);
// update projection lines
DSP4.world_x += (DSP4.world_dx + DSP4.world_xenv);
DSP4.world_y += DSP4.world_dy;
// update road turnoff position
DSP4.view_turnoff_x += DSP4.view_turnoff_dx;
////////////////////////////////////////////////////
// command check
// scan next command
DSP4.in_count = 2;
DSP4_WAIT(1);
resume1:
// check for termination
DSP4.distance = DSP4_READ_WORD();
if (DSP4.distance == -0x8000)
break;
// road turnoff
if ((uint16) DSP4.distance == 0x8001)
{
DSP4.in_count = 6;
DSP4_WAIT(2);
resume2:
DSP4.distance = DSP4_READ_WORD();
DSP4.view_turnoff_x = DSP4_READ_WORD();
DSP4.view_turnoff_dx = DSP4_READ_WORD();
// factor in new changes
DSP4.view_x1 += (DSP4.view_turnoff_x * DSP4.distance >> 15);
DSP4.view_xofs1 += (DSP4.view_turnoff_x * DSP4.distance >> 15);
// update stepping values
DSP4.view_turnoff_x += DSP4.view_turnoff_dx;
DSP4.in_count = 2;
DSP4_WAIT(1);
}
// already have 2 bytes read
DSP4.in_count = 6;
DSP4_WAIT(3);
resume3:
// inspect inputs
DSP4.world_ddy = DSP4_READ_WORD();
DSP4.world_ddx = DSP4_READ_WORD();
DSP4.view_yofsenv = DSP4_READ_WORD();
// no envelope here
DSP4.world_xenv = 0;
}
while (1);
// terminate op
DSP4.waiting4command = TRUE;
}
static void DSP4_OP03 (void)
{
DSP4.OAM_RowMax = 33;
memset(DSP4.OAM_Row, 0, 64);
}
static void DSP4_OP05 (void)
{
DSP4.OAM_index = 0;
DSP4.OAM_bits = 0;
memset(DSP4.OAM_attr, 0, 32);
DSP4.sprite_count = 0;
}
static void DSP4_OP06 (void)
{
DSP4_CLEAR_OUT();
DSP4_WRITE_16_WORD(DSP4.OAM_attr);
}
static void DSP4_OP07 (void)
{
DSP4.waiting4command = FALSE;
// op flow control
switch (DSP4.Logic)
{
case 1: goto resume1; break;
case 2: goto resume2; break;
}
////////////////////////////////////////////////////
// sort inputs
DSP4.world_y = DSP4_READ_DWORD();
DSP4.poly_bottom[0][0] = DSP4_READ_WORD();
DSP4.poly_top[0][0] = DSP4_READ_WORD();
DSP4.poly_cx[1][0] = DSP4_READ_WORD();
DSP4.viewport_bottom = DSP4_READ_WORD();
DSP4.world_x = DSP4_READ_DWORD();
DSP4.poly_cx[0][0] = DSP4_READ_WORD();
DSP4.poly_ptr[0][0] = DSP4_READ_WORD();
DSP4.world_yofs = DSP4_READ_WORD();
DSP4.distance = DSP4_READ_WORD();
DSP4.view_y2 = DSP4_READ_WORD();
DSP4.view_dy = DSP4_READ_WORD() * DSP4.distance >> 15;
DSP4.view_x2 = DSP4_READ_WORD();
DSP4.view_dx = DSP4_READ_WORD() * DSP4.distance >> 15;
DSP4.view_yofsenv = DSP4_READ_WORD();
// initial (x, y, offset) at starting raster line
DSP4.view_x1 = DSP4.world_x >> 16;
DSP4.view_y1 = DSP4.world_y >> 16;
DSP4.view_xofs1 = DSP4.view_x1;
DSP4.view_yofs1 = DSP4.world_yofs;
// first raster line
DSP4.poly_raster[0][0] = DSP4.poly_bottom[0][0];
do
{
////////////////////////////////////////////////////
// process one iteration of projection
// add shaping
DSP4.view_x2 += DSP4.view_dx;
DSP4.view_y2 += DSP4.view_dy;
// vertical scroll calculation
DSP4.view_xofs2 = DSP4.view_x2;
DSP4.view_yofs2 = (DSP4.world_yofs * DSP4.distance >> 15) + DSP4.poly_bottom[0][0] - DSP4.view_y2;
// 1. Viewer x-position at the next
// 2. Viewer y-position below the horizon
// 3. Number of raster lines drawn in this iteration
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(DSP4.view_x2);
DSP4_WRITE_WORD(DSP4.view_y2);
//////////////////////////////////////////////////////
// SR = 0x00
// determine # of raster lines used
DSP4.segments = DSP4.view_y1 - DSP4.view_y2;
// prevent overdraw
if (DSP4.view_y2 >= DSP4.poly_raster[0][0])
DSP4.segments = 0;
else
DSP4.poly_raster[0][0] = DSP4.view_y2;
// don't draw outside the window
if (DSP4.view_y2 < DSP4.poly_top[0][0])
{
DSP4.segments = 0;
// flush remaining raster lines
if (DSP4.view_y1 >= DSP4.poly_top[0][0])
DSP4.segments = DSP4.view_y1 - DSP4.poly_top[0][0];
}
// SR = 0x80
DSP4_WRITE_WORD(DSP4.segments);
//////////////////////////////////////////////////////
// scan next command if no SR check needed
if (DSP4.segments)
{
int32 px_dx, py_dy;
int32 x_scroll, y_scroll;
// SR = 0x00
// linear interpolation (lerp) between projected points
px_dx = (DSP4.view_xofs2 - DSP4.view_xofs1) * DSP4_Inverse(DSP4.segments) << 1;
py_dy = (DSP4.view_yofs2 - DSP4.view_yofs1) * DSP4_Inverse(DSP4.segments) << 1;
// starting step values
x_scroll = SEX16(DSP4.poly_cx[0][0] + DSP4.view_xofs1);
y_scroll = SEX16(-DSP4.viewport_bottom + DSP4.view_yofs1 + DSP4.view_yofsenv + DSP4.poly_cx[1][0] - DSP4.world_yofs);
// SR = 0x80
// rasterize line
for (DSP4.lcv = 0; DSP4.lcv < DSP4.segments; DSP4.lcv++)
{
// 1. HDMA memory pointer (bg2)
// 2. vertical scroll offset ($2110)
// 3. horizontal scroll offset ($210F)
DSP4_WRITE_WORD(DSP4.poly_ptr[0][0]);
DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16);
DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16);
// update memory address
DSP4.poly_ptr[0][0] -= 4;
// update screen values
x_scroll += px_dx;
y_scroll += py_dy;
}
}
/////////////////////////////////////////////////////
// Post-update
// update new viewer (x, y, scroll) to last raster line drawn
DSP4.view_x1 = DSP4.view_x2;
DSP4.view_y1 = DSP4.view_y2;
DSP4.view_xofs1 = DSP4.view_xofs2;
DSP4.view_yofs1 = DSP4.view_yofs2;
////////////////////////////////////////////////////
// command check
// scan next command
DSP4.in_count = 2;
DSP4_WAIT(1);
resume1:
// check for opcode termination
DSP4.distance = DSP4_READ_WORD();
if (DSP4.distance == -0x8000)
break;
// already have 2 bytes in queue
DSP4.in_count = 10;
DSP4_WAIT(2);
resume2:
// inspect inputs
DSP4.view_y2 = DSP4_READ_WORD();
DSP4.view_dy = DSP4_READ_WORD() * DSP4.distance >> 15;
DSP4.view_x2 = DSP4_READ_WORD();
DSP4.view_dx = DSP4_READ_WORD() * DSP4.distance >> 15;
DSP4.view_yofsenv = DSP4_READ_WORD();
}
while (1);
DSP4.waiting4command = TRUE;
}
static void DSP4_OP08 (void)
{
int16 win_left, win_right;
int16 view_x[2], view_y[2];
int16 envelope[2][2];
DSP4.waiting4command = FALSE;
// op flow control
switch (DSP4.Logic)
{
case 1: goto resume1; break;
case 2: goto resume2; break;
}
////////////////////////////////////////////////////
// process initial inputs for two polygons
// clip values
DSP4.poly_clipRt[0][0] = DSP4_READ_WORD();
DSP4.poly_clipRt[0][1] = DSP4_READ_WORD();
DSP4.poly_clipRt[1][0] = DSP4_READ_WORD();
DSP4.poly_clipRt[1][1] = DSP4_READ_WORD();
DSP4.poly_clipLf[0][0] = DSP4_READ_WORD();
DSP4.poly_clipLf[0][1] = DSP4_READ_WORD();
DSP4.poly_clipLf[1][0] = DSP4_READ_WORD();
DSP4.poly_clipLf[1][1] = DSP4_READ_WORD();
// unknown (constant) (ex. 1P/2P = $00A6, $00A6, $00A6, $00A6)
DSP4_READ_WORD();
DSP4_READ_WORD();
DSP4_READ_WORD();
DSP4_READ_WORD();
// unknown (constant) (ex. 1P/2P = $00A5, $00A5, $00A7, $00A7)
DSP4_READ_WORD();
DSP4_READ_WORD();
DSP4_READ_WORD();
DSP4_READ_WORD();
// polygon centering (left, right)
DSP4.poly_cx[0][0] = DSP4_READ_WORD();
DSP4.poly_cx[0][1] = DSP4_READ_WORD();
DSP4.poly_cx[1][0] = DSP4_READ_WORD();
DSP4.poly_cx[1][1] = DSP4_READ_WORD();
// HDMA pointer locations
DSP4.poly_ptr[0][0] = DSP4_READ_WORD();
DSP4.poly_ptr[0][1] = DSP4_READ_WORD();
DSP4.poly_ptr[1][0] = DSP4_READ_WORD();
DSP4.poly_ptr[1][1] = DSP4_READ_WORD();
// starting raster line below the horizon
DSP4.poly_bottom[0][0] = DSP4_READ_WORD();
DSP4.poly_bottom[0][1] = DSP4_READ_WORD();
DSP4.poly_bottom[1][0] = DSP4_READ_WORD();
DSP4.poly_bottom[1][1] = DSP4_READ_WORD();
// top boundary line to clip
DSP4.poly_top[0][0] = DSP4_READ_WORD();
DSP4.poly_top[0][1] = DSP4_READ_WORD();
DSP4.poly_top[1][0] = DSP4_READ_WORD();
DSP4.poly_top[1][1] = DSP4_READ_WORD();
// unknown
// (ex. 1P = $2FC8, $0034, $FF5C, $0035)
//
// (ex. 2P = $3178, $0034, $FFCC, $0035)
// (ex. 2P = $2FC8, $0034, $FFCC, $0035)
DSP4_READ_WORD();
DSP4_READ_WORD();
DSP4_READ_WORD();
DSP4_READ_WORD();
// look at guidelines for both polygon shapes
DSP4.distance = DSP4_READ_WORD();
view_x[0] = DSP4_READ_WORD();
view_y[0] = DSP4_READ_WORD();
view_x[1] = DSP4_READ_WORD();
view_y[1] = DSP4_READ_WORD();
// envelope shaping guidelines (one frame only)
envelope[0][0] = DSP4_READ_WORD();
envelope[0][1] = DSP4_READ_WORD();
envelope[1][0] = DSP4_READ_WORD();
envelope[1][1] = DSP4_READ_WORD();
// starting base values to project from
DSP4.poly_start[0] = view_x[0];
DSP4.poly_start[1] = view_x[1];
// starting raster lines to begin drawing
DSP4.poly_raster[0][0] = view_y[0];
DSP4.poly_raster[0][1] = view_y[0];
DSP4.poly_raster[1][0] = view_y[1];
DSP4.poly_raster[1][1] = view_y[1];
// starting distances
DSP4.poly_plane[0] = DSP4.distance;
DSP4.poly_plane[1] = DSP4.distance;
// SR = 0x00
// re-center coordinates
win_left = DSP4.poly_cx[0][0] - view_x[0] + envelope[0][0];
win_right = DSP4.poly_cx[0][1] - view_x[0] + envelope[0][1];
// saturate offscreen data for polygon #1
if (win_left < DSP4.poly_clipLf[0][0])
win_left = DSP4.poly_clipLf[0][0];
if (win_left > DSP4.poly_clipRt[0][0])
win_left = DSP4.poly_clipRt[0][0];
if (win_right < DSP4.poly_clipLf[0][1])
win_right = DSP4.poly_clipLf[0][1];
if (win_right > DSP4.poly_clipRt[0][1])
win_right = DSP4.poly_clipRt[0][1];
// SR = 0x80
// initial output for polygon #1
DSP4_CLEAR_OUT();
DSP4_WRITE_BYTE(win_left & 0xff);
DSP4_WRITE_BYTE(win_right & 0xff);
do
{
int16 polygon;
////////////////////////////////////////////////////
// command check
// scan next command
DSP4.in_count = 2;
DSP4_WAIT(1);
resume1:
// terminate op
DSP4.distance = DSP4_READ_WORD();
if (DSP4.distance == -0x8000)
break;
// already have 2 bytes in queue
DSP4.in_count = 16;
DSP4_WAIT(2);
resume2:
// look at guidelines for both polygon shapes
view_x[0] = DSP4_READ_WORD();
view_y[0] = DSP4_READ_WORD();
view_x[1] = DSP4_READ_WORD();
view_y[1] = DSP4_READ_WORD();
// envelope shaping guidelines (one frame only)
envelope[0][0] = DSP4_READ_WORD();
envelope[0][1] = DSP4_READ_WORD();
envelope[1][0] = DSP4_READ_WORD();
envelope[1][1] = DSP4_READ_WORD();
////////////////////////////////////////////////////
// projection begins
// init
DSP4_CLEAR_OUT();
//////////////////////////////////////////////
// solid polygon renderer - 2 shapes
for (polygon = 0; polygon < 2; polygon++)
{
int32 left_inc, right_inc;
int16 x1_final, x2_final;
int16 env[2][2];
int16 poly;
// SR = 0x00
// # raster lines to draw
DSP4.segments = DSP4.poly_raster[polygon][0] - view_y[polygon];
// prevent overdraw
if (DSP4.segments > 0)
{
// bump drawing cursor
DSP4.poly_raster[polygon][0] = view_y[polygon];
DSP4.poly_raster[polygon][1] = view_y[polygon];
}
else
DSP4.segments = 0;
// don't draw outside the window
if (view_y[polygon] < DSP4.poly_top[polygon][0])
{
DSP4.segments = 0;
// flush remaining raster lines
if (view_y[polygon] >= DSP4.poly_top[polygon][0])
DSP4.segments = view_y[polygon] - DSP4.poly_top[polygon][0];
}
// SR = 0x80
// tell user how many raster structures to read in
DSP4_WRITE_WORD(DSP4.segments);
// normal parameters
poly = polygon;
/////////////////////////////////////////////////////
// scan next command if no SR check needed
if (DSP4.segments)
{
int32 w_left, w_right;
// road turnoff selection
if ((uint16) envelope[polygon][0] == (uint16) 0xc001)
poly = 1;
else
if (envelope[polygon][1] == 0x3fff)
poly = 1;
///////////////////////////////////////////////
// left side of polygon
// perspective correction on additional shaping parameters
env[0][0] = envelope[polygon][0] * DSP4.poly_plane[poly] >> 15;
env[0][1] = envelope[polygon][0] * DSP4.distance >> 15;
// project new shapes (left side)
x1_final = view_x[poly] + env[0][0];
x2_final = DSP4.poly_start[poly] + env[0][1];
// interpolate between projected points with shaping
left_inc = (x2_final - x1_final) * DSP4_Inverse(DSP4.segments) << 1;
if (DSP4.segments == 1)
left_inc = -left_inc;
///////////////////////////////////////////////
// right side of polygon
// perspective correction on additional shaping parameters
env[1][0] = envelope[polygon][1] * DSP4.poly_plane[poly] >> 15;
env[1][1] = envelope[polygon][1] * DSP4.distance >> 15;
// project new shapes (right side)
x1_final = view_x[poly] + env[1][0];
x2_final = DSP4.poly_start[poly] + env[1][1];
// interpolate between projected points with shaping
right_inc = (x2_final - x1_final) * DSP4_Inverse(DSP4.segments) << 1;
if (DSP4.segments == 1)
right_inc = -right_inc;
///////////////////////////////////////////////
// update each point on the line
w_left = SEX16(DSP4.poly_cx[polygon][0] - DSP4.poly_start[poly] + env[0][0]);
w_right = SEX16(DSP4.poly_cx[polygon][1] - DSP4.poly_start[poly] + env[1][0]);
// update distance drawn into world
DSP4.poly_plane[polygon] = DSP4.distance;
// rasterize line
for (DSP4.lcv = 0; DSP4.lcv < DSP4.segments; DSP4.lcv++)
{
int16 x_left, x_right;
// project new coordinates
w_left += left_inc;
w_right += right_inc;
// grab integer portion, drop fraction (no rounding)
x_left = w_left >> 16;
x_right = w_right >> 16;
// saturate offscreen data
if (x_left < DSP4.poly_clipLf[polygon][0])
x_left = DSP4.poly_clipLf[polygon][0];
if (x_left > DSP4.poly_clipRt[polygon][0])
x_left = DSP4.poly_clipRt[polygon][0];
if (x_right < DSP4.poly_clipLf[polygon][1])
x_right = DSP4.poly_clipLf[polygon][1];
if (x_right > DSP4.poly_clipRt[polygon][1])
x_right = DSP4.poly_clipRt[polygon][1];
// 1. HDMA memory pointer
// 2. Left window position ($2126/$2128)
// 3. Right window position ($2127/$2129)
DSP4_WRITE_WORD(DSP4.poly_ptr[polygon][0]);
DSP4_WRITE_BYTE(x_left & 0xff);
DSP4_WRITE_BYTE(x_right & 0xff);
// update memory pointers
DSP4.poly_ptr[polygon][0] -= 4;
DSP4.poly_ptr[polygon][1] -= 4;
} // end rasterize line
}
////////////////////////////////////////////////
// Post-update
// new projection spot to continue rasterizing from
DSP4.poly_start[polygon] = view_x[poly];
} // end polygon rasterizer
}
while (1);
// unknown output
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(0);
DSP4.waiting4command = TRUE;
}
static void DSP4_OP09 (void)
{
DSP4.waiting4command = FALSE;
// op flow control
switch (DSP4.Logic)
{
case 1: goto resume1; break;
case 2: goto resume2; break;
case 3: goto resume3; break;
case 4: goto resume4; break;
case 5: goto resume5; break;
case 6: goto resume6; break;
}
////////////////////////////////////////////////////
// process initial inputs
// grab screen information
DSP4.viewport_cx = DSP4_READ_WORD();
DSP4.viewport_cy = DSP4_READ_WORD();
DSP4_READ_WORD(); // 0x0000
DSP4.viewport_left = DSP4_READ_WORD();
DSP4.viewport_right = DSP4_READ_WORD();
DSP4.viewport_top = DSP4_READ_WORD();
DSP4.viewport_bottom = DSP4_READ_WORD();
// starting raster line below the horizon
DSP4.poly_bottom[0][0] = DSP4.viewport_bottom - DSP4.viewport_cy;
DSP4.poly_raster[0][0] = 0x100;
do
{
////////////////////////////////////////////////////
// check for new sprites
DSP4.in_count = 4;
DSP4_WAIT(1);
resume1:
////////////////////////////////////////////////
// raster overdraw check
DSP4.raster = DSP4_READ_WORD();
// continue updating the raster line where overdraw begins
if (DSP4.raster < DSP4.poly_raster[0][0])
{
DSP4.sprite_clipy = DSP4.viewport_bottom - (DSP4.poly_bottom[0][0] - DSP4.raster);
DSP4.poly_raster[0][0] = DSP4.raster;
}
/////////////////////////////////////////////////
// identify sprite
// op termination
DSP4.distance = DSP4_READ_WORD();
if (DSP4.distance == -0x8000)
goto terminate;
// no sprite
if (DSP4.distance == 0x0000)
continue;
////////////////////////////////////////////////////
// process projection information
// vehicle sprite
if ((uint16) DSP4.distance == 0x9000)
{
int16 car_left, car_right, car_back;
int16 impact_left, impact_back;
int16 world_spx, world_spy;
int16 view_spx, view_spy;
uint16 energy;
// we already have 4 bytes we want
DSP4.in_count = 14;
DSP4_WAIT(2);
resume2:
// filter inputs
energy = DSP4_READ_WORD();
impact_back = DSP4_READ_WORD();
car_back = DSP4_READ_WORD();
impact_left = DSP4_READ_WORD();
car_left = DSP4_READ_WORD();
DSP4.distance = DSP4_READ_WORD();
car_right = DSP4_READ_WORD();
// calculate car's world (x, y) values
world_spx = car_right - car_left;
world_spy = car_back;
// add in collision vector [needs bit-twiddling]
world_spx -= energy * (impact_left - car_left) >> 16;
world_spy -= energy * (car_back - impact_back) >> 16;
// perspective correction for world (x, y)
view_spx = world_spx * DSP4.distance >> 15;
view_spy = world_spy * DSP4.distance >> 15;
// convert to screen values
DSP4.sprite_x = DSP4.viewport_cx + view_spx;
DSP4.sprite_y = DSP4.viewport_bottom - (DSP4.poly_bottom[0][0] - view_spy);
// make the car's (x)-coordinate available
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(world_spx);
// grab a few remaining vehicle values
DSP4.in_count = 4;
DSP4_WAIT(3);
resume3:
// add vertical lift factor
DSP4.sprite_y += DSP4_READ_WORD();
}
// terrain sprite
else
{
int16 world_spx, world_spy;
int16 view_spx, view_spy;
// we already have 4 bytes we want
DSP4.in_count = 10;
DSP4_WAIT(4);
resume4:
// sort loop inputs
DSP4.poly_cx[0][0] = DSP4_READ_WORD();
DSP4.poly_raster[0][1] = DSP4_READ_WORD();
world_spx = DSP4_READ_WORD();
world_spy = DSP4_READ_WORD();
// compute base raster line from the bottom
DSP4.segments = DSP4.poly_bottom[0][0] - DSP4.raster;
// perspective correction for world (x, y)
view_spx = world_spx * DSP4.distance >> 15;
view_spy = world_spy * DSP4.distance >> 15;
// convert to screen values
DSP4.sprite_x = DSP4.viewport_cx + view_spx - DSP4.poly_cx[0][0];
DSP4.sprite_y = DSP4.viewport_bottom - DSP4.segments + view_spy;
}
// default sprite size: 16x16
DSP4.sprite_size = 1;
DSP4.sprite_attr = DSP4_READ_WORD();
////////////////////////////////////////////////////
// convert tile data to SNES OAM format
do
{
int16 sp_x, sp_y, sp_attr, sp_dattr;
int16 sp_dx, sp_dy;
int16 pixels;
uint16 header;
bool8 draw;
DSP4.in_count = 2;
DSP4_WAIT(5);
resume5:
draw = TRUE;
// opcode termination
DSP4.raster = DSP4_READ_WORD();
if (DSP4.raster == -0x8000)
goto terminate;
// stop code
if (DSP4.raster == 0x0000 && !DSP4.sprite_size)
break;
// toggle sprite size
if (DSP4.raster == 0x0000)
{
DSP4.sprite_size = !DSP4.sprite_size;
continue;
}
// check for valid sprite header
header = DSP4.raster;
header >>= 8;
if (header != 0x20 &&
header != 0x2e && // This is for attractor sprite
header != 0x40 &&
header != 0x60 &&
header != 0xa0 &&
header != 0xc0 &&
header != 0xe0)
break;
// read in rest of sprite data
DSP4.in_count = 4;
DSP4_WAIT(6);
resume6:
draw = TRUE;
/////////////////////////////////////
// process tile data
// sprite deltas
sp_dattr = DSP4.raster;
sp_dy = DSP4_READ_WORD();
sp_dx = DSP4_READ_WORD();
// update coordinates to screen space
sp_x = DSP4.sprite_x + sp_dx;
sp_y = DSP4.sprite_y + sp_dy;
// update sprite nametable/attribute information
sp_attr = DSP4.sprite_attr + sp_dattr;
// allow partially visibile tiles
pixels = DSP4.sprite_size ? 15 : 7;
DSP4_CLEAR_OUT();
// transparent tile to clip off parts of a sprite (overdraw)
if (DSP4.sprite_clipy - pixels <= sp_y && sp_y <= DSP4.sprite_clipy && sp_x >= DSP4.viewport_left - pixels && sp_x <= DSP4.viewport_right && DSP4.sprite_clipy >= DSP4.viewport_top - pixels && DSP4.sprite_clipy <= DSP4.viewport_bottom)
DSP4_OP0B(&draw, sp_x, DSP4.sprite_clipy, 0x00EE, DSP4.sprite_size, 0);
// normal sprite tile
if (sp_x >= DSP4.viewport_left - pixels && sp_x <= DSP4.viewport_right && sp_y >= DSP4.viewport_top - pixels && sp_y <= DSP4.viewport_bottom && sp_y <= DSP4.sprite_clipy)
DSP4_OP0B(&draw, sp_x, sp_y, sp_attr, DSP4.sprite_size, 0);
// no following OAM data
DSP4_OP0B(&draw, 0, 0x0100, 0, 0, 1);
}
while (1);
}
while (1);
terminate:
DSP4.waiting4command = TRUE;
}
static void DSP4_OP0A (int16 n2, int16 *o1, int16 *o2, int16 *o3, int16 *o4)
{
const uint16 OP0A_Values[16] =
{
0x0000, 0x0030, 0x0060, 0x0090, 0x00c0, 0x00f0, 0x0120, 0x0150,
0xfe80, 0xfeb0, 0xfee0, 0xff10, 0xff40, 0xff70, 0xffa0, 0xffd0
};
*o4 = OP0A_Values[(n2 & 0x000f)];
*o3 = OP0A_Values[(n2 & 0x00f0) >> 4];
*o2 = OP0A_Values[(n2 & 0x0f00) >> 8];
*o1 = OP0A_Values[(n2 & 0xf000) >> 12];
}
static void DSP4_OP0B (bool8 *draw, int16 sp_x, int16 sp_y, int16 sp_attr, bool8 size, bool8 stop)
{
int16 Row1, Row2;
// SR = 0x00
// align to nearest 8-pixel row
Row1 = (sp_y >> 3) & 0x1f;
Row2 = (Row1 + 1) & 0x1f;
// check boundaries
if (!((sp_y < 0) || ((sp_y & 0x01ff) < 0x00eb)))
*draw = 0;
if (size)
{
if (DSP4.OAM_Row[Row1] + 1 >= DSP4.OAM_RowMax)
*draw = 0;
if (DSP4.OAM_Row[Row2] + 1 >= DSP4.OAM_RowMax)
*draw = 0;
}
else
{
if (DSP4.OAM_Row[Row1] >= DSP4.OAM_RowMax)
*draw = 0;
}
// emulator fail-safe (unknown if this really exists)
if (DSP4.sprite_count >= 128)
*draw = 0;
// SR = 0x80
if (*draw)
{
// Row tiles
if (size)
{
DSP4.OAM_Row[Row1] += 2;
DSP4.OAM_Row[Row2] += 2;
}
else
DSP4.OAM_Row[Row1]++;
// yield OAM output
DSP4_WRITE_WORD(1);
// pack OAM data: x, y, name, attr
DSP4_WRITE_BYTE(sp_x & 0xff);
DSP4_WRITE_BYTE(sp_y & 0xff);
DSP4_WRITE_WORD(sp_attr);
DSP4.sprite_count++;
// OAM: size, msb data
// save post-oam table data for future retrieval
DSP4.OAM_attr[DSP4.OAM_index] |= ((sp_x < 0 || sp_x > 255) << DSP4.OAM_bits);
DSP4.OAM_bits++;
DSP4.OAM_attr[DSP4.OAM_index] |= (size << DSP4.OAM_bits);
DSP4.OAM_bits++;
// move to next byte in buffer
if (DSP4.OAM_bits == 16)
{
DSP4.OAM_bits = 0;
DSP4.OAM_index++;
}
}
else
if (stop)
// yield no OAM output
DSP4_WRITE_WORD(0);
}
static void DSP4_OP0D (void)
{
DSP4.waiting4command = FALSE;
// op flow control
switch (DSP4.Logic)
{
case 1: goto resume1; break;
case 2: goto resume2; break;
}
////////////////////////////////////////////////////
// process initial inputs
// sort inputs
DSP4.world_y = DSP4_READ_DWORD();
DSP4.poly_bottom[0][0] = DSP4_READ_WORD();
DSP4.poly_top[0][0] = DSP4_READ_WORD();
DSP4.poly_cx[1][0] = DSP4_READ_WORD();
DSP4.viewport_bottom = DSP4_READ_WORD();
DSP4.world_x = DSP4_READ_DWORD();
DSP4.poly_cx[0][0] = DSP4_READ_WORD();
DSP4.poly_ptr[0][0] = DSP4_READ_WORD();
DSP4.world_yofs = DSP4_READ_WORD();
DSP4.world_dy = DSP4_READ_DWORD();
DSP4.world_dx = DSP4_READ_DWORD();
DSP4.distance = DSP4_READ_WORD();
DSP4_READ_WORD(); // 0x0000
DSP4.world_xenv = SEX78(DSP4_READ_WORD());
DSP4.world_ddy = DSP4_READ_WORD();
DSP4.world_ddx = DSP4_READ_WORD();
DSP4.view_yofsenv = DSP4_READ_WORD();
// initial (x, y, offset) at starting raster line
DSP4.view_x1 = (DSP4.world_x + DSP4.world_xenv) >> 16;
DSP4.view_y1 = DSP4.world_y >> 16;
DSP4.view_xofs1 = DSP4.world_x >> 16;
DSP4.view_yofs1 = DSP4.world_yofs;
// first raster line
DSP4.poly_raster[0][0] = DSP4.poly_bottom[0][0];
do
{
////////////////////////////////////////////////////
// process one iteration of projection
// perspective projection of world (x, y, scroll) points
// based on the current projection lines
DSP4.view_x2 = (((DSP4.world_x + DSP4.world_xenv) >> 16) * DSP4.distance >> 15) + (DSP4.view_turnoff_x * DSP4.distance >> 15);
DSP4.view_y2 = (DSP4.world_y >> 16) * DSP4.distance >> 15;
DSP4.view_xofs2 = DSP4.view_x2;
DSP4.view_yofs2 = (DSP4.world_yofs * DSP4.distance >> 15) + DSP4.poly_bottom[0][0] - DSP4.view_y2;
// 1. World x-location before transformation
// 2. Viewer x-position at the current
// 3. World y-location before perspective projection
// 4. Viewer y-position below the horizon
// 5. Number of raster lines drawn in this iteration
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD((DSP4.world_x + DSP4.world_xenv) >> 16);
DSP4_WRITE_WORD(DSP4.view_x2);
DSP4_WRITE_WORD(DSP4.world_y >> 16);
DSP4_WRITE_WORD(DSP4.view_y2);
//////////////////////////////////////////////////////////
// SR = 0x00
// determine # of raster lines used
DSP4.segments = DSP4.view_y1 - DSP4.view_y2;
// prevent overdraw
if (DSP4.view_y2 >= DSP4.poly_raster[0][0])
DSP4.segments = 0;
else
DSP4.poly_raster[0][0] = DSP4.view_y2;
// don't draw outside the window
if (DSP4.view_y2 < DSP4.poly_top[0][0])
{
DSP4.segments = 0;
// flush remaining raster lines
if (DSP4.view_y1 >= DSP4.poly_top[0][0])
DSP4.segments = DSP4.view_y1 - DSP4.poly_top[0][0];
}
// SR = 0x80
DSP4_WRITE_WORD(DSP4.segments);
//////////////////////////////////////////////////////////
// scan next command if no SR check needed
if (DSP4.segments)
{
int32 px_dx, py_dy;
int32 x_scroll, y_scroll;
// SR = 0x00
// linear interpolation (lerp) between projected points
px_dx = (DSP4.view_xofs2 - DSP4.view_xofs1) * DSP4_Inverse(DSP4.segments) << 1;
py_dy = (DSP4.view_yofs2 - DSP4.view_yofs1) * DSP4_Inverse(DSP4.segments) << 1;
// starting step values
x_scroll = SEX16(DSP4.poly_cx[0][0] + DSP4.view_xofs1);
y_scroll = SEX16(-DSP4.viewport_bottom + DSP4.view_yofs1 + DSP4.view_yofsenv + DSP4.poly_cx[1][0] - DSP4.world_yofs);
// SR = 0x80
// rasterize line
for (DSP4.lcv = 0; DSP4.lcv < DSP4.segments; DSP4.lcv++)
{
// 1. HDMA memory pointer (bg1)
// 2. vertical scroll offset ($210E)
// 3. horizontal scroll offset ($210D)
DSP4_WRITE_WORD(DSP4.poly_ptr[0][0]);
DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16);
DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16);
// update memory address
DSP4.poly_ptr[0][0] -= 4;
// update screen values
x_scroll += px_dx;
y_scroll += py_dy;
}
}
/////////////////////////////////////////////////////
// Post-update
// update new viewer (x, y, scroll) to last raster line drawn
DSP4.view_x1 = DSP4.view_x2;
DSP4.view_y1 = DSP4.view_y2;
DSP4.view_xofs1 = DSP4.view_xofs2;
DSP4.view_yofs1 = DSP4.view_yofs2;
// add deltas for projection lines
DSP4.world_dx += SEX78(DSP4.world_ddx);
DSP4.world_dy += SEX78(DSP4.world_ddy);
// update projection lines
DSP4.world_x += (DSP4.world_dx + DSP4.world_xenv);
DSP4.world_y += DSP4.world_dy;
////////////////////////////////////////////////////
// command check
// scan next command
DSP4.in_count = 2;
DSP4_WAIT(1);
resume1:
// inspect input
DSP4.distance = DSP4_READ_WORD();
// terminate op
if (DSP4.distance == -0x8000)
break;
// already have 2 bytes in queue
DSP4.in_count = 6;
DSP4_WAIT(2);
resume2:
// inspect inputs
DSP4.world_ddy = DSP4_READ_WORD();
DSP4.world_ddx = DSP4_READ_WORD();
DSP4.view_yofsenv = DSP4_READ_WORD();
// no envelope here
DSP4.world_xenv = 0;
}
while (1);
DSP4.waiting4command = TRUE;
}
static void DSP4_OP0E (void)
{
DSP4.OAM_RowMax = 16;
memset(DSP4.OAM_Row, 0, 64);
}
static void DSP4_OP0F (void)
{
DSP4.waiting4command = FALSE;
// op flow control
switch (DSP4.Logic)
{
case 1: goto resume1; break;
case 2: goto resume2; break;
case 3: goto resume3; break;
case 4: goto resume4; break;
}
////////////////////////////////////////////////////
// process initial inputs
// sort inputs
DSP4_READ_WORD(); // 0x0000
DSP4.world_y = DSP4_READ_DWORD();
DSP4.poly_bottom[0][0] = DSP4_READ_WORD();
DSP4.poly_top[0][0] = DSP4_READ_WORD();
DSP4.poly_cx[1][0] = DSP4_READ_WORD();
DSP4.viewport_bottom = DSP4_READ_WORD();
DSP4.world_x = DSP4_READ_DWORD();
DSP4.poly_cx[0][0] = DSP4_READ_WORD();
DSP4.poly_ptr[0][0] = DSP4_READ_WORD();
DSP4.world_yofs = DSP4_READ_WORD();
DSP4.world_dy = DSP4_READ_DWORD();
DSP4.world_dx = DSP4_READ_DWORD();
DSP4.distance = DSP4_READ_WORD();
DSP4_READ_WORD(); // 0x0000
DSP4.world_xenv = DSP4_READ_DWORD();
DSP4.world_ddy = DSP4_READ_WORD();
DSP4.world_ddx = DSP4_READ_WORD();
DSP4.view_yofsenv = DSP4_READ_WORD();
// initial (x, y, offset) at starting raster line
DSP4.view_x1 = (DSP4.world_x + DSP4.world_xenv) >> 16;
DSP4.view_y1 = DSP4.world_y >> 16;
DSP4.view_xofs1 = DSP4.world_x >> 16;
DSP4.view_yofs1 = DSP4.world_yofs;
DSP4.view_turnoff_x = 0;
DSP4.view_turnoff_dx = 0;
// first raster line
DSP4.poly_raster[0][0] = DSP4.poly_bottom[0][0];
do
{
////////////////////////////////////////////////////
// process one iteration of projection
// perspective projection of world (x, y, scroll) points
// based on the current projection lines
DSP4.view_x2 = ((DSP4.world_x + DSP4.world_xenv) >> 16) * DSP4.distance >> 15;
DSP4.view_y2 = (DSP4.world_y >> 16) * DSP4.distance >> 15;
DSP4.view_xofs2 = DSP4.view_x2;
DSP4.view_yofs2 = (DSP4.world_yofs * DSP4.distance >> 15) + DSP4.poly_bottom[0][0] - DSP4.view_y2;
// 1. World x-location before transformation
// 2. Viewer x-position at the next
// 3. World y-location before perspective projection
// 4. Viewer y-position below the horizon
// 5. Number of raster lines drawn in this iteration
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD((DSP4.world_x + DSP4.world_xenv) >> 16);
DSP4_WRITE_WORD(DSP4.view_x2);
DSP4_WRITE_WORD(DSP4.world_y >> 16);
DSP4_WRITE_WORD(DSP4.view_y2);
//////////////////////////////////////////////////////
// SR = 0x00
// determine # of raster lines used
DSP4.segments = DSP4.poly_raster[0][0] - DSP4.view_y2;
// prevent overdraw
if (DSP4.view_y2 >= DSP4.poly_raster[0][0])
DSP4.segments = 0;
else
DSP4.poly_raster[0][0] = DSP4.view_y2;
// don't draw outside the window
if (DSP4.view_y2 < DSP4.poly_top[0][0])
{
DSP4.segments = 0;
// flush remaining raster lines
if (DSP4.view_y1 >= DSP4.poly_top[0][0])
DSP4.segments = DSP4.view_y1 - DSP4.poly_top[0][0];
}
// SR = 0x80
DSP4_WRITE_WORD(DSP4.segments);
//////////////////////////////////////////////////////
// scan next command if no SR check needed
if (DSP4.segments)
{
int32 px_dx, py_dy;
int32 x_scroll, y_scroll;
for (DSP4.lcv = 0; DSP4.lcv < 4; DSP4.lcv++)
{
// grab inputs
DSP4.in_count = 4;
DSP4_WAIT(1);
resume1:
for (;;)
{
int16 dist;
int16 color, red, green, blue;
dist = DSP4_READ_WORD();
color = DSP4_READ_WORD();
// U1+B5+G5+R5
red = color & 0x1f;
green = (color >> 5) & 0x1f;
blue = (color >> 10) & 0x1f;
// dynamic lighting
red = (red * dist >> 15) & 0x1f;
green = (green * dist >> 15) & 0x1f;
blue = (blue * dist >> 15) & 0x1f;
color = red | (green << 5) | (blue << 10);
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(color);
break;
}
}
//////////////////////////////////////////////////////
// SR = 0x00
// linear interpolation (lerp) between projected points
px_dx = (DSP4.view_xofs2 - DSP4.view_xofs1) * DSP4_Inverse(DSP4.segments) << 1;
py_dy = (DSP4.view_yofs2 - DSP4.view_yofs1) * DSP4_Inverse(DSP4.segments) << 1;
// starting step values
x_scroll = SEX16(DSP4.poly_cx[0][0] + DSP4.view_xofs1);
y_scroll = SEX16(-DSP4.viewport_bottom + DSP4.view_yofs1 + DSP4.view_yofsenv + DSP4.poly_cx[1][0] - DSP4.world_yofs);
// SR = 0x80
// rasterize line
for (DSP4.lcv = 0; DSP4.lcv < DSP4.segments; DSP4.lcv++)
{
// 1. HDMA memory pointer
// 2. vertical scroll offset ($210E)
// 3. horizontal scroll offset ($210D)
DSP4_WRITE_WORD(DSP4.poly_ptr[0][0]);
DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16);
DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16);
// update memory address
DSP4.poly_ptr[0][0] -= 4;
// update screen values
x_scroll += px_dx;
y_scroll += py_dy;
}
}
////////////////////////////////////////////////////
// Post-update
// update new viewer (x, y, scroll) to last raster line drawn
DSP4.view_x1 = DSP4.view_x2;
DSP4.view_y1 = DSP4.view_y2;
DSP4.view_xofs1 = DSP4.view_xofs2;
DSP4.view_yofs1 = DSP4.view_yofs2;
// add deltas for projection lines
DSP4.world_dx += SEX78(DSP4.world_ddx);
DSP4.world_dy += SEX78(DSP4.world_ddy);
// update projection lines
DSP4.world_x += (DSP4.world_dx + DSP4.world_xenv);
DSP4.world_y += DSP4.world_dy;
// update road turnoff position
DSP4.view_turnoff_x += DSP4.view_turnoff_dx;
////////////////////////////////////////////////////
// command check
// scan next command
DSP4.in_count = 2;
DSP4_WAIT(2);
resume2:
// check for termination
DSP4.distance = DSP4_READ_WORD();
if (DSP4.distance == -0x8000)
break;
// road splice
if ((uint16) DSP4.distance == 0x8001)
{
DSP4.in_count = 6;
DSP4_WAIT(3);
resume3:
DSP4.distance = DSP4_READ_WORD();
DSP4.view_turnoff_x = DSP4_READ_WORD();
DSP4.view_turnoff_dx = DSP4_READ_WORD();
// factor in new changes
DSP4.view_x1 += (DSP4.view_turnoff_x * DSP4.distance >> 15);
DSP4.view_xofs1 += (DSP4.view_turnoff_x * DSP4.distance >> 15);
// update stepping values
DSP4.view_turnoff_x += DSP4.view_turnoff_dx;
DSP4.in_count = 2;
DSP4_WAIT(2);
}
// already have 2 bytes in queue
DSP4.in_count = 6;
DSP4_WAIT(4);
resume4:
// inspect inputs
DSP4.world_ddy = DSP4_READ_WORD();
DSP4.world_ddx = DSP4_READ_WORD();
DSP4.view_yofsenv = DSP4_READ_WORD();
// no envelope here
DSP4.world_xenv = 0;
}
while (1);
// terminate op
DSP4.waiting4command = TRUE;
}
static void DSP4_OP10 (void)
{
DSP4.waiting4command = FALSE;
// op flow control
switch (DSP4.Logic)
{
case 1: goto resume1; break;
case 2: goto resume2; break;
case 3: goto resume3; break;
}
////////////////////////////////////////////////////
// sort inputs
DSP4_READ_WORD(); // 0x0000
DSP4.world_y = DSP4_READ_DWORD();
DSP4.poly_bottom[0][0] = DSP4_READ_WORD();
DSP4.poly_top[0][0] = DSP4_READ_WORD();
DSP4.poly_cx[1][0] = DSP4_READ_WORD();
DSP4.viewport_bottom = DSP4_READ_WORD();
DSP4.world_x = DSP4_READ_DWORD();
DSP4.poly_cx[0][0] = DSP4_READ_WORD();
DSP4.poly_ptr[0][0] = DSP4_READ_WORD();
DSP4.world_yofs = DSP4_READ_WORD();
DSP4.distance = DSP4_READ_WORD();
DSP4.view_y2 = DSP4_READ_WORD();
DSP4.view_dy = DSP4_READ_WORD() * DSP4.distance >> 15;
DSP4.view_x2 = DSP4_READ_WORD();
DSP4.view_dx = DSP4_READ_WORD() * DSP4.distance >> 15;
DSP4.view_yofsenv = DSP4_READ_WORD();
// initial (x, y, offset) at starting raster line
DSP4.view_x1 = DSP4.world_x >> 16;
DSP4.view_y1 = DSP4.world_y >> 16;
DSP4.view_xofs1 = DSP4.view_x1;
DSP4.view_yofs1 = DSP4.world_yofs;
// first raster line
DSP4.poly_raster[0][0] = DSP4.poly_bottom[0][0];
do
{
////////////////////////////////////////////////////
// process one iteration of projection
// add shaping
DSP4.view_x2 += DSP4.view_dx;
DSP4.view_y2 += DSP4.view_dy;
// vertical scroll calculation
DSP4.view_xofs2 = DSP4.view_x2;
DSP4.view_yofs2 = (DSP4.world_yofs * DSP4.distance >> 15) + DSP4.poly_bottom[0][0] - DSP4.view_y2;
// 1. Viewer x-position at the next
// 2. Viewer y-position below the horizon
// 3. Number of raster lines drawn in this iteration
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(DSP4.view_x2);
DSP4_WRITE_WORD(DSP4.view_y2);
//////////////////////////////////////////////////////
// SR = 0x00
// determine # of raster lines used
DSP4.segments = DSP4.view_y1 - DSP4.view_y2;
// prevent overdraw
if (DSP4.view_y2 >= DSP4.poly_raster[0][0])
DSP4.segments = 0;
else
DSP4.poly_raster[0][0] = DSP4.view_y2;
// don't draw outside the window
if (DSP4.view_y2 < DSP4.poly_top[0][0])
{
DSP4.segments = 0;
// flush remaining raster lines
if (DSP4.view_y1 >= DSP4.poly_top[0][0])
DSP4.segments = DSP4.view_y1 - DSP4.poly_top[0][0];
}
// SR = 0x80
DSP4_WRITE_WORD(DSP4.segments);
//////////////////////////////////////////////////////
// scan next command if no SR check needed
if (DSP4.segments)
{
for (DSP4.lcv = 0; DSP4.lcv < 4; DSP4.lcv++)
{
// grab inputs
DSP4.in_count = 4;
DSP4_WAIT(1);
resume1:
for (;;)
{
int16 dist;
int16 color, red, green, blue;
dist = DSP4_READ_WORD();
color = DSP4_READ_WORD();
// U1+B5+G5+R5
red = color & 0x1f;
green = (color >> 5) & 0x1f;
blue = (color >> 10) & 0x1f;
// dynamic lighting
red = (red * dist >> 15) & 0x1f;
green = (green * dist >> 15) & 0x1f;
blue = (blue * dist >> 15) & 0x1f;
color = red | (green << 5) | (blue << 10);
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(color);
break;
}
}
}
//////////////////////////////////////////////////////
// scan next command if no SR check needed
if (DSP4.segments)
{
int32 px_dx, py_dy;
int32 x_scroll, y_scroll;
// SR = 0x00
// linear interpolation (lerp) between projected points
px_dx = (DSP4.view_xofs2 - DSP4.view_xofs1) * DSP4_Inverse(DSP4.segments) << 1;
py_dy = (DSP4.view_yofs2 - DSP4.view_yofs1) * DSP4_Inverse(DSP4.segments) << 1;
// starting step values
x_scroll = SEX16(DSP4.poly_cx[0][0] + DSP4.view_xofs1);
y_scroll = SEX16(-DSP4.viewport_bottom + DSP4.view_yofs1 + DSP4.view_yofsenv + DSP4.poly_cx[1][0] - DSP4.world_yofs);
// SR = 0x80
// rasterize line
for (DSP4.lcv = 0; DSP4.lcv < DSP4.segments; DSP4.lcv++)
{
// 1. HDMA memory pointer (bg2)
// 2. vertical scroll offset ($2110)
// 3. horizontal scroll offset ($210F)
DSP4_WRITE_WORD(DSP4.poly_ptr[0][0]);
DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16);
DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16);
// update memory address
DSP4.poly_ptr[0][0] -= 4;
// update screen values
x_scroll += px_dx;
y_scroll += py_dy;
}
}
/////////////////////////////////////////////////////
// Post-update
// update new viewer (x, y, scroll) to last raster line drawn
DSP4.view_x1 = DSP4.view_x2;
DSP4.view_y1 = DSP4.view_y2;
DSP4.view_xofs1 = DSP4.view_xofs2;
DSP4.view_yofs1 = DSP4.view_yofs2;
////////////////////////////////////////////////////
// command check
// scan next command
DSP4.in_count = 2;
DSP4_WAIT(2);
resume2:
// check for opcode termination
DSP4.distance = DSP4_READ_WORD();
if (DSP4.distance == -0x8000)
break;
// already have 2 bytes in queue
DSP4.in_count = 10;
DSP4_WAIT(3);
resume3:
// inspect inputs
DSP4.view_y2 = DSP4_READ_WORD();
DSP4.view_dy = DSP4_READ_WORD() * DSP4.distance >> 15;
DSP4.view_x2 = DSP4_READ_WORD();
DSP4.view_dx = DSP4_READ_WORD() * DSP4.distance >> 15;
}
while (1);
DSP4.waiting4command = TRUE;
}
static void DSP4_OP11 (int16 A, int16 B, int16 C, int16 D, int16 *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);
}
static void DSP4_SetByte (void)
{
// clear pending read
if (DSP4.out_index < DSP4.out_count)
{
DSP4.out_index++;
return;
}
if (DSP4.waiting4command)
{
if (DSP4.half_command)
{
DSP4.command |= (DSP4.byte << 8);
DSP4.in_index = 0;
DSP4.waiting4command = FALSE;
DSP4.half_command = FALSE;
DSP4.out_count = 0;
DSP4.out_index = 0;
DSP4.Logic = 0;
switch (DSP4.command)
{
case 0x0000: DSP4.in_count = 4; break;
case 0x0001: DSP4.in_count = 44; break;
case 0x0003: DSP4.in_count = 0; break;
case 0x0005: DSP4.in_count = 0; break;
case 0x0006: DSP4.in_count = 0; break;
case 0x0007: DSP4.in_count = 34; break;
case 0x0008: DSP4.in_count = 90; break;
case 0x0009: DSP4.in_count = 14; break;
case 0x000a: DSP4.in_count = 6; break;
case 0x000b: DSP4.in_count = 6; break;
case 0x000d: DSP4.in_count = 42; break;
case 0x000e: DSP4.in_count = 0; break;
case 0x000f: DSP4.in_count = 46; break;
case 0x0010: DSP4.in_count = 36; break;
case 0x0011: DSP4.in_count = 8; break;
default:
DSP4.waiting4command = TRUE;
break;
}
}
else
{
DSP4.command = DSP4.byte;
DSP4.half_command = TRUE;
}
}
else
{
DSP4.parameters[DSP4.in_index] = DSP4.byte;
DSP4.in_index++;
}
if (!DSP4.waiting4command && DSP4.in_count == DSP4.in_index)
{
// Actually execute the command
DSP4.waiting4command = TRUE;
DSP4.out_index = 0;
DSP4.in_index = 0;
switch (DSP4.command)
{
// 16-bit multiplication
case 0x0000:
{
int16 multiplier, multiplicand;
int32 product;
multiplier = DSP4_READ_WORD();
multiplicand = DSP4_READ_WORD();
DSP4_Multiply(multiplicand, multiplier, &product);
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(product);
DSP4_WRITE_WORD(product >> 16);
break;
}
// single-player track projection
case 0x0001:
DSP4_OP01();
break;
// single-player selection
case 0x0003:
DSP4_OP03();
break;
// clear OAM
case 0x0005:
DSP4_OP05();
break;
// transfer OAM
case 0x0006:
DSP4_OP06();
break;
// single-player track turnoff projection
case 0x0007:
DSP4_OP07();
break;
// solid polygon projection
case 0x0008:
DSP4_OP08();
break;
// sprite projection
case 0x0009:
DSP4_OP09();
break;
// unknown
case 0x000A:
{
DSP4_READ_WORD();
int16 in2a = DSP4_READ_WORD();
DSP4_READ_WORD();
int16 out1a, out2a, out3a, out4a;
DSP4_OP0A(in2a, &out2a, &out1a, &out4a, &out3a);
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(out1a);
DSP4_WRITE_WORD(out2a);
DSP4_WRITE_WORD(out3a);
DSP4_WRITE_WORD(out4a);
break;
}
// set OAM
case 0x000B:
{
int16 sp_x = DSP4_READ_WORD();
int16 sp_y = DSP4_READ_WORD();
int16 sp_attr = DSP4_READ_WORD();
bool8 draw = TRUE;
DSP4_CLEAR_OUT();
DSP4_OP0B(&draw, sp_x, sp_y, sp_attr, 0, 1);
break;
}
// multi-player track projection
case 0x000D:
DSP4_OP0D();
break;
// multi-player selection
case 0x000E:
DSP4_OP0E();
break;
// single-player track projection with lighting
case 0x000F:
DSP4_OP0F();
break;
// single-player track turnoff projection with lighting
case 0x0010:
DSP4_OP10();
break;
// unknown: horizontal mapping command
case 0x0011:
{
int16 a, b, c, d, m;
d = DSP4_READ_WORD();
c = DSP4_READ_WORD();
b = DSP4_READ_WORD();
a = DSP4_READ_WORD();
DSP4_OP11(a, b, c, d, &m);
DSP4_CLEAR_OUT();
DSP4_WRITE_WORD(m);
break;
}
default:
break;
}
}
}
static void DSP4_GetByte (void)
{
if (DSP4.out_count)
{
DSP4.byte = (uint8) DSP4.output[DSP4.out_index & 0x1FF];
DSP4.out_index++;
if (DSP4.out_count == DSP4.out_index)
DSP4.out_count = 0;
}
else
DSP4.byte = 0xff;
}
void DSP4SetByte (uint8 byte, uint16 address)
{
if (address < DSP0.boundary)
{
DSP4.byte = byte;
DSP4.address = address;
DSP4_SetByte();
}
}
uint8 DSP4GetByte (uint16 address)
{
if (address < DSP0.boundary)
{
DSP4.address = address;
DSP4_GetByte();
return (DSP4.byte);
}
return (0x80);
}
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