/********************************************************************************** Snes9x - Portable Super Nintendo Entertainment System (TM) emulator. (c) Copyright 1996 - 2002 Gary Henderson (gary.henderson@ntlworld.com) and 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 Brad Jorsch (anomie@users.sourceforge.net), funkyass (funkyass@spam.shaw.ca), Kris Bleakley (codeviolation@hotmail.com), Nach (n-a-c-h@users.sourceforge.net), and zones (kasumitokoduck@yahoo.com) 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 filter (c) Copyright 2003 Maxim Stepin (maxim@hiend3d.com) 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. **********************************************************************************/ #include "snes9x.h" #include "memmap.h" #include /* 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') */ typedef struct { bool8 waiting4command; bool8 half_command; uint16 command; uint32 in_count; uint32 in_index; uint32 out_count; uint32 out_index; uint8 parameters[512]; uint8 output[512]; } SDSP4; SDSP4 DSP4; //Todo: get all of this into a struct for easy save stating // op control int8 DSP4_Logic; // controls op flow // projection format int16 lcv; // loop-control variable int16 distance; // z-position into virtual world int16 raster; // current raster line int16 segments; // number of raster lines drawn // 1.15.16 or 1.15.0 [sign, integer, fraction] int32 world_x; // line of x-projection in world int32 world_y; // line of y-projection in world int32 world_dx; // projection line x-delta int32 world_dy; // projection line y-delta int16 world_ddx; // x-delta increment int16 world_ddy; // y-delta increment int32 world_xenv; // world x-shaping factor int16 world_yofs; // world y-vertical scroll int16 view_x1; // current viewer-x int16 view_y1; // current viewer-y int16 view_x2; // future viewer-x int16 view_y2; // future viewer-y int16 view_dx; // view x-delta factor int16 view_dy; // view y-delta factor int16 view_xofs1; // current viewer x-vertical scroll int16 view_yofs1; // current viewer y-vertical scroll int16 view_xofs2; // future viewer x-vertical scroll int16 view_yofs2; // future viewer y-vertical scroll int16 view_yofsenv; // y-scroll shaping factor int16 view_turnoff_x; // road turnoff data int16 view_turnoff_dx; // road turnoff delta factor // drawing area int16 viewport_cx; // x-center of viewport window int16 viewport_cy; // y-center of render window int16 viewport_left; // x-left of viewport int16 viewport_right; // x-right of viewport int16 viewport_top; // y-top of viewport int16 viewport_bottom; // y-bottom of viewport // sprite structure int16 sprite_x; // projected x-pos of sprite int16 sprite_y; // projected y-pos of sprite int16 sprite_attr; // obj attributes bool8 sprite_size; // sprite size: 8x8 or 16x16 int16 sprite_clipy; // visible line to clip pixels off int16 sprite_count; // generic projection variables designed for // two solid polygons + two polygon sides int16 poly_clipLf[2][2]; // left clip boundary int16 poly_clipRt[2][2]; // right clip boundary int16 poly_ptr[2][2]; // HDMA structure pointers int16 poly_raster[2][2]; // current raster line below horizon int16 poly_top[2][2]; // top clip boundary int16 poly_bottom[2][2]; // bottom clip boundary int16 poly_cx[2][2]; // center for left/right points int16 poly_start[2]; // current projection points int16 poly_plane[2]; // previous z-plane distance // OAM int16 OAM_attr[16]; // OAM (size,MSB) data int16 OAM_index; // index into OAM table int16 OAM_bits; // offset into OAM table int16 OAM_RowMax; // maximum number of tiles per 8 aligned pixels (row) int16 OAM_Row[32]; // current number of tiles per row ////////////////////////////////////////////////////////////// // input protocol static int16 DSP4_READ_WORD() { int16 out; out = READ_WORD(DSP4.parameters + DSP4.in_index); DSP4.in_index += 2; return out; } static int32 DSP4_READ_DWORD() { int32 out; out = READ_DWORD(DSP4.parameters + DSP4.in_index); DSP4.in_index += 4; return out; } ////////////////////////////////////////////////////////////// // output protocol #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 #ifdef PRINT_OP #define DSP4_WRITE_DEBUG( x, d ) \ WRITE_WORD( nop + x, d ); #endif #ifdef DEBUG_DSP #define DSP4_WRITE_DEBUG( x, d ) \ WRITE_WORD( nop + x, d ); #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 ) #ifdef PRINT_OP #define U16( a ) ( (uint16) ( a ) ) #endif #ifdef DEBUG_DSP #define U16( a ) ( (uint16) ( a ) ) #endif ////////////////////////////////////////////////////////////// // 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, }; int16 DSP4_Inverse(int16 value) { // saturate bounds if (value < 0) { value = 0; } if (value > 63) { value = 63; } return div_lut[value]; } ////////////////////////////////////////////////////////////// // Prototype void DSP4_OP0B(bool8 *draw, int16 sp_x, int16 sp_y, int16 sp_attr, bool8 size, bool8 stop); ////////////////////////////////////////////////////////////// // OP00 void DSP4_Multiply(int16 Multiplicand, int16 Multiplier, int32 *Product) { *Product = (Multiplicand * Multiplier << 1) >> 1; } ////////////////////////////////////////////////////////////// void DSP4_OP01() { 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 world_y = DSP4_READ_DWORD(); poly_bottom[0][0] = DSP4_READ_WORD(); poly_top[0][0] = DSP4_READ_WORD(); poly_cx[1][0] = DSP4_READ_WORD(); viewport_bottom = DSP4_READ_WORD(); world_x = DSP4_READ_DWORD(); poly_cx[0][0] = DSP4_READ_WORD(); poly_ptr[0][0] = DSP4_READ_WORD(); world_yofs = DSP4_READ_WORD(); world_dy = DSP4_READ_DWORD(); world_dx = DSP4_READ_DWORD(); distance = DSP4_READ_WORD(); DSP4_READ_WORD(); // 0x0000 world_xenv = DSP4_READ_DWORD(); world_ddy = DSP4_READ_WORD(); world_ddx = DSP4_READ_WORD(); view_yofsenv = DSP4_READ_WORD(); // initial (x,y,offset) at starting raster line view_x1 = (world_x + world_xenv) >> 16; view_y1 = world_y >> 16; view_xofs1 = world_x >> 16; view_yofs1 = world_yofs; view_turnoff_x = 0; view_turnoff_dx = 0; // first raster line poly_raster[0][0] = poly_bottom[0][0]; do { //////////////////////////////////////////////////// // process one iteration of projection // perspective projection of world (x,y,scroll) points // based on the current projection lines view_x2 = ( ( ( world_x + world_xenv ) >> 16 ) * distance >> 15 ) + ( view_turnoff_x * distance >> 15 ); view_y2 = (world_y >> 16) * distance >> 15; view_xofs2 = view_x2; view_yofs2 = (world_yofs * distance >> 15) + poly_bottom[0][0] - 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((world_x + world_xenv) >> 16); DSP4_WRITE_WORD(view_x2); DSP4_WRITE_WORD(world_y >> 16); DSP4_WRITE_WORD(view_y2); ////////////////////////////////////////////////////// // SR = 0x00 // determine # of raster lines used segments = poly_raster[0][0] - view_y2; // prevent overdraw if (view_y2 >= poly_raster[0][0]) segments = 0; else poly_raster[0][0] = view_y2; // don't draw outside the window if (view_y2 < poly_top[0][0]) { segments = 0; // flush remaining raster lines if (view_y1 >= poly_top[0][0]) segments = view_y1 - poly_top[0][0]; } // SR = 0x80 DSP4_WRITE_WORD(segments); ////////////////////////////////////////////////////// // scan next command if no SR check needed if (segments) { int32 px_dx, py_dy; int32 x_scroll, y_scroll; // SR = 0x00 // linear interpolation (lerp) between projected points px_dx = (view_xofs2 - view_xofs1) * DSP4_Inverse(segments) << 1; py_dy = (view_yofs2 - view_yofs1) * DSP4_Inverse(segments) << 1; // starting step values x_scroll = SEX16(poly_cx[0][0] + view_xofs1); y_scroll = SEX16(-viewport_bottom + view_yofs1 + view_yofsenv + poly_cx[1][0] - world_yofs); // SR = 0x80 // rasterize line for (lcv = 0; lcv < segments; lcv++) { // 1. HDMA memory pointer (bg1) // 2. vertical scroll offset ($210E) // 3. horizontal scroll offset ($210D) DSP4_WRITE_WORD(poly_ptr[0][0]); DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16); DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16); // update memory address 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 view_x1 = view_x2; view_y1 = view_y2; view_xofs1 = view_xofs2; view_yofs1 = view_yofs2; // add deltas for projection lines world_dx += SEX78(world_ddx); world_dy += SEX78(world_ddy); // update projection lines world_x += (world_dx + world_xenv); world_y += world_dy; // update road turnoff position view_turnoff_x += view_turnoff_dx; //////////////////////////////////////////////////// // command check // scan next command DSP4.in_count = 2; DSP4_WAIT(1) resume1 : // check for termination distance = DSP4_READ_WORD(); if (distance == -0x8000) break; // road turnoff if( (uint16) distance == 0x8001 ) { DSP4.in_count = 6; DSP4_WAIT(2) resume2: distance = DSP4_READ_WORD(); view_turnoff_x = DSP4_READ_WORD(); view_turnoff_dx = DSP4_READ_WORD(); // factor in new changes view_x1 += ( view_turnoff_x * distance >> 15 ); view_xofs1 += ( view_turnoff_x * distance >> 15 ); // update stepping values view_turnoff_x += 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 world_ddy = DSP4_READ_WORD(); world_ddx = DSP4_READ_WORD(); view_yofsenv = DSP4_READ_WORD(); // no envelope here world_xenv = 0; } while (1); // terminate op DSP4.waiting4command = TRUE; } ////////////////////////////////////////////////////////////// void DSP4_OP03() { OAM_RowMax = 33; memset(OAM_Row, 0, 64); } ////////////////////////////////////////////////////////////// void DSP4_OP05() { OAM_index = 0; OAM_bits = 0; memset(OAM_attr, 0, 32); sprite_count = 0; } ////////////////////////////////////////////////////////////// void DSP4_OP06() { DSP4_CLEAR_OUT(); DSP4_WRITE_16_WORD(OAM_attr); } ////////////////////////////////////////////////////////////// void DSP4_OP07() { DSP4.waiting4command = FALSE; // op flow control switch (DSP4_Logic) { case 1: goto resume1; break; case 2: goto resume2; break; } //////////////////////////////////////////////////// // sort inputs world_y = DSP4_READ_DWORD(); poly_bottom[0][0] = DSP4_READ_WORD(); poly_top[0][0] = DSP4_READ_WORD(); poly_cx[1][0] = DSP4_READ_WORD(); viewport_bottom = DSP4_READ_WORD(); world_x = DSP4_READ_DWORD(); poly_cx[0][0] = DSP4_READ_WORD(); poly_ptr[0][0] = DSP4_READ_WORD(); world_yofs = DSP4_READ_WORD(); distance = DSP4_READ_WORD(); view_y2 = DSP4_READ_WORD(); view_dy = DSP4_READ_WORD() * distance >> 15; view_x2 = DSP4_READ_WORD(); view_dx = DSP4_READ_WORD() * distance >> 15; view_yofsenv = DSP4_READ_WORD(); // initial (x,y,offset) at starting raster line view_x1 = world_x >> 16; view_y1 = world_y >> 16; view_xofs1 = view_x1; view_yofs1 = world_yofs; // first raster line poly_raster[0][0] = poly_bottom[0][0]; do { //////////////////////////////////////////////////// // process one iteration of projection // add shaping view_x2 += view_dx; view_y2 += view_dy; // vertical scroll calculation view_xofs2 = view_x2; view_yofs2 = (world_yofs * distance >> 15) + poly_bottom[0][0] - 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(view_x2); DSP4_WRITE_WORD(view_y2); ////////////////////////////////////////////////////// // SR = 0x00 // determine # of raster lines used segments = view_y1 - view_y2; // prevent overdraw if (view_y2 >= poly_raster[0][0]) segments = 0; else poly_raster[0][0] = view_y2; // don't draw outside the window if (view_y2 < poly_top[0][0]) { segments = 0; // flush remaining raster lines if (view_y1 >= poly_top[0][0]) segments = view_y1 - poly_top[0][0]; } // SR = 0x80 DSP4_WRITE_WORD(segments); ////////////////////////////////////////////////////// // scan next command if no SR check needed if (segments) { int32 px_dx, py_dy; int32 x_scroll, y_scroll; // SR = 0x00 // linear interpolation (lerp) between projected points px_dx = (view_xofs2 - view_xofs1) * DSP4_Inverse(segments) << 1; py_dy = (view_yofs2 - view_yofs1) * DSP4_Inverse(segments) << 1; // starting step values x_scroll = SEX16(poly_cx[0][0] + view_xofs1); y_scroll = SEX16(-viewport_bottom + view_yofs1 + view_yofsenv + poly_cx[1][0] - world_yofs); // SR = 0x80 // rasterize line for (lcv = 0; lcv < segments; lcv++) { // 1. HDMA memory pointer (bg2) // 2. vertical scroll offset ($2110) // 3. horizontal scroll offset ($210F) DSP4_WRITE_WORD(poly_ptr[0][0]); DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16); DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16); // update memory address 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 view_x1 = view_x2; view_y1 = view_y2; view_xofs1 = view_xofs2; view_yofs1 = view_yofs2; //////////////////////////////////////////////////// // command check // scan next command DSP4.in_count = 2; DSP4_WAIT(1) resume1 : // check for opcode termination distance = DSP4_READ_WORD(); if (distance == -0x8000) break; // already have 2 bytes in queue DSP4.in_count = 10; DSP4_WAIT(2) resume2 : // inspect inputs view_y2 = DSP4_READ_WORD(); view_dy = DSP4_READ_WORD() * distance >> 15; view_x2 = DSP4_READ_WORD(); view_dx = DSP4_READ_WORD() * distance >> 15; view_yofsenv = DSP4_READ_WORD(); } while (1); DSP4.waiting4command = TRUE; } ////////////////////////////////////////////////////////////// void DSP4_OP08() { 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 poly_clipRt[0][0] = DSP4_READ_WORD(); poly_clipRt[0][1] = DSP4_READ_WORD(); poly_clipRt[1][0] = DSP4_READ_WORD(); poly_clipRt[1][1] = DSP4_READ_WORD(); poly_clipLf[0][0] = DSP4_READ_WORD(); poly_clipLf[0][1] = DSP4_READ_WORD(); poly_clipLf[1][0] = DSP4_READ_WORD(); 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) poly_cx[0][0] = DSP4_READ_WORD(); poly_cx[0][1] = DSP4_READ_WORD(); poly_cx[1][0] = DSP4_READ_WORD(); poly_cx[1][1] = DSP4_READ_WORD(); // HDMA pointer locations poly_ptr[0][0] = DSP4_READ_WORD(); poly_ptr[0][1] = DSP4_READ_WORD(); poly_ptr[1][0] = DSP4_READ_WORD(); poly_ptr[1][1] = DSP4_READ_WORD(); // starting raster line below the horizon poly_bottom[0][0] = DSP4_READ_WORD(); poly_bottom[0][1] = DSP4_READ_WORD(); poly_bottom[1][0] = DSP4_READ_WORD(); poly_bottom[1][1] = DSP4_READ_WORD(); // top boundary line to clip poly_top[0][0] = DSP4_READ_WORD(); poly_top[0][1] = DSP4_READ_WORD(); poly_top[1][0] = DSP4_READ_WORD(); 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 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 poly_start[0] = view_x[0]; poly_start[1] = view_x[1]; // starting raster lines to begin drawing poly_raster[0][0] = view_y[0]; poly_raster[0][1] = view_y[0]; poly_raster[1][0] = view_y[1]; poly_raster[1][1] = view_y[1]; // starting distances poly_plane[0] = distance; poly_plane[1] = distance; // SR = 0x00 // re-center coordinates win_left = poly_cx[0][0] - view_x[0] + envelope[0][0]; win_right = poly_cx[0][1] - view_x[0] + envelope[0][1]; // saturate offscreen data for polygon #1 if (win_left < poly_clipLf[0][0]) { win_left = poly_clipLf[0][0]; } if (win_left > poly_clipRt[0][0]) { win_left = poly_clipRt[0][0]; } if (win_right < poly_clipLf[0][1]) { win_right = poly_clipLf[0][1]; } if (win_right > poly_clipRt[0][1]) { win_right = 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 distance = DSP4_READ_WORD(); if (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 segments = poly_raster[polygon][0] - view_y[polygon]; // prevent overdraw if (segments > 0) { // bump drawing cursor poly_raster[polygon][0] = view_y[polygon]; poly_raster[polygon][1] = view_y[polygon]; } else segments = 0; // don't draw outside the window if (view_y[polygon] < poly_top[polygon][0]) { segments = 0; // flush remaining raster lines if (view_y[polygon] >= poly_top[polygon][0]) segments = view_y[polygon] - poly_top[polygon][0]; } // SR = 0x80 // tell user how many raster structures to read in DSP4_WRITE_WORD(segments); // normal parameters poly = polygon; ///////////////////////////////////////////////////// // scan next command if no SR check needed if (segments) { int32 win_left, win_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] * poly_plane[poly] >> 15; env[0][1] = envelope[polygon][0] * distance >> 15; // project new shapes (left side) x1_final = view_x[poly] + env[0][0]; x2_final = poly_start[poly] + env[0][1]; // interpolate between projected points with shaping left_inc = (x2_final - x1_final) * DSP4_Inverse(segments) << 1; if (segments == 1) left_inc = -left_inc; /////////////////////////////////////////////// // right side of polygon // perspective correction on additional shaping parameters env[1][0] = envelope[polygon][1] * poly_plane[poly] >> 15;; env[1][1] = envelope[polygon][1] * distance >> 15; // project new shapes (right side) x1_final = view_x[poly] + env[1][0]; x2_final = poly_start[poly] + env[1][1]; // interpolate between projected points with shaping right_inc = (x2_final - x1_final) * DSP4_Inverse(segments) << 1; if (segments == 1) right_inc = -right_inc; /////////////////////////////////////////////// // update each point on the line win_left = SEX16(poly_cx[polygon][0] - poly_start[poly] + env[0][0]); win_right = SEX16(poly_cx[polygon][1] - poly_start[poly] + env[1][0]); // update distance drawn into world poly_plane[polygon] = distance; // rasterize line for (lcv = 0; lcv < segments; lcv++) { int16 x_left, x_right; // project new coordinates win_left += left_inc; win_right += right_inc; // grab integer portion, drop fraction (no rounding) x_left = win_left >> 16; x_right = win_right >> 16; // saturate offscreen data if (x_left < poly_clipLf[polygon][0]) x_left = poly_clipLf[polygon][0]; if (x_left > poly_clipRt[polygon][0]) x_left = poly_clipRt[polygon][0]; if (x_right < poly_clipLf[polygon][1]) x_right = poly_clipLf[polygon][1]; if (x_right > poly_clipRt[polygon][1]) x_right = poly_clipRt[polygon][1]; // 1. HDMA memory pointer // 2. Left window position ($2126/$2128) // 3. Right window position ($2127/$2129) DSP4_WRITE_WORD(poly_ptr[polygon][0]); DSP4_WRITE_BYTE(x_left & 0xff); DSP4_WRITE_BYTE(x_right & 0xff); // update memory pointers poly_ptr[polygon][0] -= 4; poly_ptr[polygon][1] -= 4; } // end rasterize line } //////////////////////////////////////////////// // Post-update // new projection spot to continue rasterizing from poly_start[polygon] = view_x[poly]; } // end polygon rasterizer } while (1); // unknown output DSP4_CLEAR_OUT(); DSP4_WRITE_WORD(0); DSP4.waiting4command = TRUE; } ////////////////////////////////////////////////////////////// void DSP4_OP09() { 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 viewport_cx = DSP4_READ_WORD(); viewport_cy = DSP4_READ_WORD(); DSP4_READ_WORD(); // 0x0000 viewport_left = DSP4_READ_WORD(); viewport_right = DSP4_READ_WORD(); viewport_top = DSP4_READ_WORD(); viewport_bottom = DSP4_READ_WORD(); // starting raster line below the horizon poly_bottom[0][0] = viewport_bottom - viewport_cy; poly_raster[0][0] = 0x100; do { //////////////////////////////////////////////////// // check for new sprites DSP4.in_count = 4; DSP4_WAIT(1) resume1 : //////////////////////////////////////////////// // raster overdraw check raster = DSP4_READ_WORD(); // continue updating the raster line where overdraw begins if (raster < poly_raster[0][0]) { sprite_clipy = viewport_bottom - (poly_bottom[0][0] - raster); poly_raster[0][0] = raster; } ///////////////////////////////////////////////// // identify sprite // op termination distance = DSP4_READ_WORD(); if (distance == -0x8000) goto terminate; // no sprite if (distance == 0x0000) { continue; } //////////////////////////////////////////////////// // process projection information // vehicle sprite if ((uint16) 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(); 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 * distance >> 15; view_spy = world_spy * distance >> 15; // convert to screen values sprite_x = viewport_cx + view_spx; sprite_y = viewport_bottom - (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 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 poly_cx[0][0] = DSP4_READ_WORD(); poly_raster[0][1] = DSP4_READ_WORD(); world_spx = DSP4_READ_WORD(); world_spy = DSP4_READ_WORD(); // compute base raster line from the bottom segments = poly_bottom[0][0] - raster; // perspective correction for world (x,y) view_spx = world_spx * distance >> 15; view_spy = world_spy * distance >> 15; // convert to screen values sprite_x = viewport_cx + view_spx - poly_cx[0][0]; sprite_y = viewport_bottom - segments + view_spy; } // default sprite size: 16x16 sprite_size = 1; sprite_attr = DSP4_READ_WORD(); //////////////////////////////////////////////////// // convert tile data to SNES OAM format do { uint16 header; int16 sp_x, sp_y, sp_attr, sp_dattr; int16 sp_dx, sp_dy; int16 pixels; bool8 draw; DSP4.in_count = 2; DSP4_WAIT(5) resume5 : draw = TRUE; // opcode termination raster = DSP4_READ_WORD(); if (raster == -0x8000) goto terminate; // stop code if (raster == 0x0000 && !sprite_size) break; // toggle sprite size if (raster == 0x0000) { sprite_size = !sprite_size; continue; } // check for valid sprite header header = 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 = raster; sp_dy = DSP4_READ_WORD(); sp_dx = DSP4_READ_WORD(); // update coordinates to screen space sp_x = sprite_x + sp_dx; sp_y = sprite_y + sp_dy; // update sprite nametable/attribute information sp_attr = sprite_attr + sp_dattr; // allow partially visibile tiles pixels = sprite_size ? 15 : 7; DSP4_CLEAR_OUT(); // transparent tile to clip off parts of a sprite (overdraw) if (sprite_clipy - pixels <= sp_y && sp_y <= sprite_clipy && sp_x >= viewport_left - pixels && sp_x <= viewport_right && sprite_clipy >= viewport_top - pixels && sprite_clipy <= viewport_bottom) { DSP4_OP0B(&draw, sp_x, sprite_clipy, 0x00EE, sprite_size, 0); } // normal sprite tile if (sp_x >= viewport_left - pixels && sp_x <= viewport_right && sp_y >= viewport_top - pixels && sp_y <= viewport_bottom && sp_y <= sprite_clipy) { DSP4_OP0B(&draw, sp_x, sp_y, sp_attr, sprite_size, 0); } // no following OAM data DSP4_OP0B(&draw, 0, 0x0100, 0, 0, 1); } while (1); } while (1); terminate : DSP4.waiting4command = TRUE; } ////////////////////////////////////////////////////////////// const uint16 OP0A_Values[16] = { 0x0000, 0x0030, 0x0060, 0x0090, 0x00c0, 0x00f0, 0x0120, 0x0150, 0xfe80, 0xfeb0, 0xfee0, 0xff10, 0xff40, 0xff70, 0xffa0, 0xffd0 }; void DSP4_OP0A(int16 n2, int16 *o1, int16 *o2, int16 *o3, int16 *o4) { *o4 = OP0A_Values[(n2 & 0x000f)]; *o3 = OP0A_Values[(n2 & 0x00f0) >> 4]; *o2 = OP0A_Values[(n2 & 0x0f00) >> 8]; *o1 = OP0A_Values[(n2 & 0xf000) >> 12]; } ////////////////////////////////////////////////////////////// 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 (OAM_Row[Row1] + 1 >= OAM_RowMax) *draw = 0; if (OAM_Row[Row2] + 1 >= OAM_RowMax) *draw = 0; } else { if (OAM_Row[Row1] >= OAM_RowMax) { *draw = 0; } } // emulator fail-safe (unknown if this really exists) if (sprite_count >= 128) { *draw = 0; } // SR = 0x80 if (*draw) { // Row tiles if (size) { OAM_Row[Row1] += 2; OAM_Row[Row2] += 2; } else { 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); sprite_count++; // OAM: size,msb data // save post-oam table data for future retrieval OAM_attr[OAM_index] |= ((sp_x <0 || sp_x> 255) << OAM_bits); OAM_bits++; OAM_attr[OAM_index] |= (size << OAM_bits); OAM_bits++; // move to next byte in buffer if (OAM_bits == 16) { OAM_bits = 0; OAM_index++; } } else if (stop) { // yield no OAM output DSP4_WRITE_WORD(0); } } ////////////////////////////////////////////////////////////// void DSP4_OP0D() { DSP4.waiting4command = FALSE; // op flow control switch (DSP4_Logic) { case 1: goto resume1; break; case 2: goto resume2; break; } //////////////////////////////////////////////////// // process initial inputs // sort inputs world_y = DSP4_READ_DWORD(); poly_bottom[0][0] = DSP4_READ_WORD(); poly_top[0][0] = DSP4_READ_WORD(); poly_cx[1][0] = DSP4_READ_WORD(); viewport_bottom = DSP4_READ_WORD(); world_x = DSP4_READ_DWORD(); poly_cx[0][0] = DSP4_READ_WORD(); poly_ptr[0][0] = DSP4_READ_WORD(); world_yofs = DSP4_READ_WORD(); world_dy = DSP4_READ_DWORD(); world_dx = DSP4_READ_DWORD(); distance = DSP4_READ_WORD(); DSP4_READ_WORD(); // 0x0000 world_xenv = SEX78(DSP4_READ_WORD()); world_ddy = DSP4_READ_WORD(); world_ddx = DSP4_READ_WORD(); view_yofsenv = DSP4_READ_WORD(); // initial (x,y,offset) at starting raster line view_x1 = (world_x + world_xenv) >> 16; view_y1 = world_y >> 16; view_xofs1 = world_x >> 16; view_yofs1 = world_yofs; // first raster line poly_raster[0][0] = poly_bottom[0][0]; do { //////////////////////////////////////////////////// // process one iteration of projection // perspective projection of world (x,y,scroll) points // based on the current projection lines view_x2 = ( ( ( world_x + world_xenv ) >> 16 ) * distance >> 15 ) + ( view_turnoff_x * distance >> 15 ); view_y2 = (world_y >> 16) * distance >> 15; view_xofs2 = view_x2; view_yofs2 = (world_yofs * distance >> 15) + poly_bottom[0][0] - 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((world_x + world_xenv) >> 16); DSP4_WRITE_WORD(view_x2); DSP4_WRITE_WORD(world_y >> 16); DSP4_WRITE_WORD(view_y2); ////////////////////////////////////////////////////////// // SR = 0x00 // determine # of raster lines used segments = view_y1 - view_y2; // prevent overdraw if (view_y2 >= poly_raster[0][0]) segments = 0; else poly_raster[0][0] = view_y2; // don't draw outside the window if (view_y2 < poly_top[0][0]) { segments = 0; // flush remaining raster lines if (view_y1 >= poly_top[0][0]) segments = view_y1 - poly_top[0][0]; } // SR = 0x80 DSP4_WRITE_WORD(segments); ////////////////////////////////////////////////////////// // scan next command if no SR check needed if (segments) { int32 px_dx, py_dy; int32 x_scroll, y_scroll; // SR = 0x00 // linear interpolation (lerp) between projected points px_dx = (view_xofs2 - view_xofs1) * DSP4_Inverse(segments) << 1; py_dy = (view_yofs2 - view_yofs1) * DSP4_Inverse(segments) << 1; // starting step values x_scroll = SEX16(poly_cx[0][0] + view_xofs1); y_scroll = SEX16(-viewport_bottom + view_yofs1 + view_yofsenv + poly_cx[1][0] - world_yofs); // SR = 0x80 // rasterize line for (lcv = 0; lcv < segments; lcv++) { // 1. HDMA memory pointer (bg1) // 2. vertical scroll offset ($210E) // 3. horizontal scroll offset ($210D) DSP4_WRITE_WORD(poly_ptr[0][0]); DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16); DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16); // update memory address 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 view_x1 = view_x2; view_y1 = view_y2; view_xofs1 = view_xofs2; view_yofs1 = view_yofs2; // add deltas for projection lines world_dx += SEX78(world_ddx); world_dy += SEX78(world_ddy); // update projection lines world_x += (world_dx + world_xenv); world_y += world_dy; //////////////////////////////////////////////////// // command check // scan next command DSP4.in_count = 2; DSP4_WAIT(1) resume1 : // inspect input distance = DSP4_READ_WORD(); // terminate op if (distance == -0x8000) break; // already have 2 bytes in queue DSP4.in_count = 6; DSP4_WAIT(2) resume2: // inspect inputs world_ddy = DSP4_READ_WORD(); world_ddx = DSP4_READ_WORD(); view_yofsenv = DSP4_READ_WORD(); // no envelope here world_xenv = 0; } while (1); DSP4.waiting4command = TRUE; } ////////////////////////////////////////////////////////////// void DSP4_OP0E() { OAM_RowMax = 16; memset(OAM_Row, 0, 64); } ////////////////////////////////////////////////////////////// void DSP4_OP0F() { 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 world_y = DSP4_READ_DWORD(); poly_bottom[0][0] = DSP4_READ_WORD(); poly_top[0][0] = DSP4_READ_WORD(); poly_cx[1][0] = DSP4_READ_WORD(); viewport_bottom = DSP4_READ_WORD(); world_x = DSP4_READ_DWORD(); poly_cx[0][0] = DSP4_READ_WORD(); poly_ptr[0][0] = DSP4_READ_WORD(); world_yofs = DSP4_READ_WORD(); world_dy = DSP4_READ_DWORD(); world_dx = DSP4_READ_DWORD(); distance = DSP4_READ_WORD(); DSP4_READ_WORD(); // 0x0000 world_xenv = DSP4_READ_DWORD(); world_ddy = DSP4_READ_WORD(); world_ddx = DSP4_READ_WORD(); view_yofsenv = DSP4_READ_WORD(); // initial (x,y,offset) at starting raster line view_x1 = (world_x + world_xenv) >> 16; view_y1 = world_y >> 16; view_xofs1 = world_x >> 16; view_yofs1 = world_yofs; view_turnoff_x = 0; view_turnoff_dx = 0; // first raster line poly_raster[0][0] = poly_bottom[0][0]; do { //////////////////////////////////////////////////// // process one iteration of projection // perspective projection of world (x,y,scroll) points // based on the current projection lines view_x2 = ((world_x + world_xenv) >> 16) * distance >> 15; view_y2 = (world_y >> 16) * distance >> 15; view_xofs2 = view_x2; view_yofs2 = (world_yofs * distance >> 15) + poly_bottom[0][0] - 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((world_x + world_xenv) >> 16); DSP4_WRITE_WORD(view_x2); DSP4_WRITE_WORD(world_y >> 16); DSP4_WRITE_WORD(view_y2); ////////////////////////////////////////////////////// // SR = 0x00 // determine # of raster lines used segments = poly_raster[0][0] - view_y2; // prevent overdraw if (view_y2 >= poly_raster[0][0]) segments = 0; else poly_raster[0][0] = view_y2; // don't draw outside the window if (view_y2 < poly_top[0][0]) { segments = 0; // flush remaining raster lines if (view_y1 >= poly_top[0][0]) segments = view_y1 - poly_top[0][0]; } // SR = 0x80 DSP4_WRITE_WORD(segments); ////////////////////////////////////////////////////// // scan next command if no SR check needed if (segments) { int32 px_dx, py_dy; int32 x_scroll, y_scroll; for (lcv = 0; lcv < 4; lcv++) { // grab inputs DSP4.in_count = 4; DSP4_WAIT(1); resume1 : for (;;) { int16 distance; int16 color, red, green, blue; distance = 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 * distance >> 15) & 0x1f; green = (green * distance >> 15) & 0x1f; blue = (blue * distance >> 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 = (view_xofs2 - view_xofs1) * DSP4_Inverse(segments) << 1; py_dy = (view_yofs2 - view_yofs1) * DSP4_Inverse(segments) << 1; // starting step values x_scroll = SEX16(poly_cx[0][0] + view_xofs1); y_scroll = SEX16(-viewport_bottom + view_yofs1 + view_yofsenv + poly_cx[1][0] - world_yofs); // SR = 0x80 // rasterize line for (lcv = 0; lcv < segments; lcv++) { // 1. HDMA memory pointer // 2. vertical scroll offset ($210E) // 3. horizontal scroll offset ($210D) DSP4_WRITE_WORD(poly_ptr[0][0]); DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16); DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16); // update memory address 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 view_x1 = view_x2; view_y1 = view_y2; view_xofs1 = view_xofs2; view_yofs1 = view_yofs2; // add deltas for projection lines world_dx += SEX78(world_ddx); world_dy += SEX78(world_ddy); // update projection lines world_x += (world_dx + world_xenv); world_y += world_dy; // update road turnoff position view_turnoff_x += view_turnoff_dx; //////////////////////////////////////////////////// // command check // scan next command DSP4.in_count = 2; DSP4_WAIT(2) resume2: // check for termination distance = DSP4_READ_WORD(); if (distance == -0x8000) break; // road splice if( (uint16) distance == 0x8001 ) { DSP4.in_count = 6; DSP4_WAIT(3) resume3: distance = DSP4_READ_WORD(); view_turnoff_x = DSP4_READ_WORD(); view_turnoff_dx = DSP4_READ_WORD(); // factor in new changes view_x1 += ( view_turnoff_x * distance >> 15 ); view_xofs1 += ( view_turnoff_x * distance >> 15 ); // update stepping values view_turnoff_x += 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 world_ddy = DSP4_READ_WORD(); world_ddx = DSP4_READ_WORD(); view_yofsenv = DSP4_READ_WORD(); // no envelope here world_xenv = 0; } while (1); // terminate op DSP4.waiting4command = TRUE; } ////////////////////////////////////////////////////////////// void DSP4_OP10() { 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 world_y = DSP4_READ_DWORD(); poly_bottom[0][0] = DSP4_READ_WORD(); poly_top[0][0] = DSP4_READ_WORD(); poly_cx[1][0] = DSP4_READ_WORD(); viewport_bottom = DSP4_READ_WORD(); world_x = DSP4_READ_DWORD(); poly_cx[0][0] = DSP4_READ_WORD(); poly_ptr[0][0] = DSP4_READ_WORD(); world_yofs = DSP4_READ_WORD(); distance = DSP4_READ_WORD(); view_y2 = DSP4_READ_WORD(); view_dy = DSP4_READ_WORD() * distance >> 15; view_x2 = DSP4_READ_WORD(); view_dx = DSP4_READ_WORD() * distance >> 15; view_yofsenv = DSP4_READ_WORD(); // initial (x,y,offset) at starting raster line view_x1 = world_x >> 16; view_y1 = world_y >> 16; view_xofs1 = view_x1; view_yofs1 = world_yofs; // first raster line poly_raster[0][0] = poly_bottom[0][0]; do { //////////////////////////////////////////////////// // process one iteration of projection // add shaping view_x2 += view_dx; view_y2 += view_dy; // vertical scroll calculation view_xofs2 = view_x2; view_yofs2 = (world_yofs * distance >> 15) + poly_bottom[0][0] - 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(view_x2); DSP4_WRITE_WORD(view_y2); ////////////////////////////////////////////////////// // SR = 0x00 // determine # of raster lines used segments = view_y1 - view_y2; // prevent overdraw if (view_y2 >= poly_raster[0][0]) segments = 0; else poly_raster[0][0] = view_y2; // don't draw outside the window if (view_y2 < poly_top[0][0]) { segments = 0; // flush remaining raster lines if (view_y1 >= poly_top[0][0]) segments = view_y1 - poly_top[0][0]; } // SR = 0x80 DSP4_WRITE_WORD(segments); ////////////////////////////////////////////////////// // scan next command if no SR check needed if (segments) { for (lcv = 0; lcv < 4; lcv++) { // grab inputs DSP4.in_count = 4; DSP4_WAIT(1); resume1 : for (;;) { int16 distance; int16 color, red, green, blue; distance = 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 * distance >> 15) & 0x1f; green = (green * distance >> 15) & 0x1f; blue = (blue * distance >> 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 (segments) { int32 px_dx, py_dy; int32 x_scroll, y_scroll; // SR = 0x00 // linear interpolation (lerp) between projected points px_dx = (view_xofs2 - view_xofs1) * DSP4_Inverse(segments) << 1; py_dy = (view_yofs2 - view_yofs1) * DSP4_Inverse(segments) << 1; // starting step values x_scroll = SEX16(poly_cx[0][0] + view_xofs1); y_scroll = SEX16(-viewport_bottom + view_yofs1 + view_yofsenv + poly_cx[1][0] - world_yofs); // SR = 0x80 // rasterize line for (lcv = 0; lcv < segments; lcv++) { // 1. HDMA memory pointer (bg2) // 2. vertical scroll offset ($2110) // 3. horizontal scroll offset ($210F) DSP4_WRITE_WORD(poly_ptr[0][0]); DSP4_WRITE_WORD((y_scroll + 0x8000) >> 16); DSP4_WRITE_WORD((x_scroll + 0x8000) >> 16); // update memory address 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 view_x1 = view_x2; view_y1 = view_y2; view_xofs1 = view_xofs2; view_yofs1 = view_yofs2; //////////////////////////////////////////////////// // command check // scan next command DSP4.in_count = 2; DSP4_WAIT(2) resume2 : // check for opcode termination distance = DSP4_READ_WORD(); if (distance == -0x8000) break; // already have 2 bytes in queue DSP4.in_count = 10; DSP4_WAIT(3) resume3 : // inspect inputs view_y2 = DSP4_READ_WORD(); view_dy = DSP4_READ_WORD() * distance >> 15; view_x2 = DSP4_READ_WORD(); view_dx = DSP4_READ_WORD() * distance >> 15; } while (1); DSP4.waiting4command = TRUE; } ////////////////////////////////////////////////////////////// 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); } ///////////////////////////////////////////////////////////// //Processing Code ///////////////////////////////////////////////////////////// uint8 dsp4_byte; uint16 dsp4_address; void InitDSP4() { memset(&DSP4, 0, sizeof(DSP4)); DSP4.waiting4command = TRUE; } void DSP4_SetByte() { // 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: { //int16 in1a = DSP4_READ_WORD(); int16 in2a = DSP4_READ_WORD(); //int16 in3a = 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 = 1; 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; } } } void DSP4_GetByte() { 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; } }