engine.c

小型游戏引擎

/*
 * "Build Engine & Tools" Copyright (c) 1993-1997 Ken Silverman
 * Ken Silverman's official web site: "http://www.advsys.net/ken"
 * See the included license file "BUILDLIC.TXT" for license info.
 * This file has been modified from Ken Silverman's original release
 */

/* SUPERBUILD define is in engine.h ... */

#define ENGINE

/* set this to something non-zero to get loadtile() debugging info on stderr. */
#define BUILD_CACHEDEBUG 0

#include <string.h>
#include <malloc.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#if (defined USE_OPENGL)
#include "buildgl.h"
#endif

#include "pragmas.h"

#include "platform.h"

#include "build.h"
#include "cache1d.h"

#include "engine.h"

long stereowidth = 23040, stereopixelwidth = 28, ostereopixelwidth = -1;
volatile long stereomode = 0, visualpage, activepage, whiteband, blackband;
volatile char oa1, o3c2, ortca, ortcb, overtbits, laststereoint;

#include "display.h"

#define MAXCLIPNUM 512
#define MAXPERMS 512
#define MAXTILEFILES 256
#define MAXYSAVES ((MAXXDIM*MAXSPRITES)>>7)
#define MAXNODESPERLINE 42   /* Warning: This depends on MAXYSAVES & MAXYDIM! */
#define MAXWALLSB 2048
#define MAXCLIPDIST 1024

#ifdef PLATFORM_DOS
	/* MUST CALL MALLOC THIS WAY TO FORCE CALLS TO KMALLOC! */
void *kmalloc(size_t size) { return(malloc(size)); }
void *kkmalloc(size_t size);
#pragma aux kkmalloc =\
	"call kmalloc",\
	parm [eax]\

	/* MUST CALL FREE THIS WAY TO FORCE CALLS TO KFREE! */
void kfree(void *buffer) { free(buffer); }
void kkfree(void *buffer);
#pragma aux kkfree =\
	"call kfree",\
	parm [eax]\

#endif

#ifdef SUPERBUILD
	/* MUST CALL LOADVOXEL THIS WAY BECAUSE WATCOM STINKS! */

/* !!! wtf does this do?! --ryan. */
static void loadvoxel(long voxindex)
{
    voxindex = 0;  /* prevent compiler whining. */
}

#if ((defined __WATCOMC__) && (defined PLATFORM_DOS))
void kloadvoxel(long voxindex);
#pragma aux kloadvoxel =\
	"call loadvoxel",\
	parm [eax]\

#else
#define kloadvoxel(a) (loadvoxel(a))
#endif

	/* These variables need to be copied into BUILD */
#define MAXXSIZ 128
#define MAXYSIZ 128
#define MAXZSIZ 200
#define MAXVOXELS 512
#define MAXVOXMIPS 5
long voxoff[MAXVOXELS][MAXVOXMIPS], voxlock[MAXVOXELS][MAXVOXMIPS];
static long ggxinc[MAXXSIZ+1], ggyinc[MAXXSIZ+1];
static long lowrecip[1024], nytooclose, nytoofar;
static unsigned long distrecip[16384];
#endif

/* used to be static. --ryan. */
char moustat = 0;

long transarea = 0, totalarea = 0, beforedrawrooms = 1;

/* used to be static. --ryan. */
long oxdimen = -1, oviewingrange = -1, oxyaspect = -1;

/* used to be static. --ryan. */
long curbrightness = 0;

	/* Textured Map variables */
static char globalpolytype;
static short *dotp1[MAXYDIM], *dotp2[MAXYDIM];

static unsigned char tempbuf[MAXWALLS];

long ebpbak, espbak;
long slopalookup[2048];

/*
 * !!! used to be static. If we ever put the original setgamemode() back, this
 * !!! can be made static again.  --ryan.
 */
unsigned char permanentlock = 255;
long artversion, mapversion;
char *pic = NULL;
char picsiz[MAXTILES], tilefilenum[MAXTILES];
long lastageclock;
long tilefileoffs[MAXTILES];

long artsize = 0, cachesize = 0;

static short radarang[1280], radarang2[MAXXDIM];
static unsigned short sqrtable[4096], shlookup[4096+256];
char pow2char[8] = {1,2,4,8,16,32,64,-128};
long pow2long[32] =
{
	1L,2L,4L,8L,
	16L,32L,64L,128L,
	256L,512L,1024L,2048L,
	4096L,8192L,16384L,32768L,
	65536L,131072L,262144L,524288L,
	1048576L,2097152L,4194304L,8388608L,
	16777216L,33554432L,67108864L,134217728L,
	268435456L,536870912L,1073741824L,2147483647L,
};
long reciptable[2048], fpuasm;

char kensmessage[128];



/* rcg02132001 Cygwin support. */
#if (defined C_IDENTIFIERS_UNDERSCORED)
#define SYM_sqrtable   "_sqrtable"
#define SYM_walock     "_walock"
#define SYM_shlookup   "_shlookup"
#define SYM_pow2char   "_pow2char"
#define SYM_gotpic     "_gotpic"
#define SYM_dmval      "_dmval"
#else
#define SYM_sqrtable   "sqrtable"
#define SYM_walock     "walock"
#define SYM_shlookup   "shlookup"
#define SYM_pow2char   "pow2char"
#define SYM_gotpic     "gotpic"
#define SYM_dmval      "dmval"
#endif

char britable[16][64];
char textfont[1024], smalltextfont[1024];

static long xb1[MAXWALLSB], yb1[MAXWALLSB], xb2[MAXWALLSB], yb2[MAXWALLSB];
static long rx1[MAXWALLSB], ry1[MAXWALLSB], rx2[MAXWALLSB], ry2[MAXWALLSB];
static short p2[MAXWALLSB], thesector[MAXWALLSB], thewall[MAXWALLSB];

static short bunchfirst[MAXWALLSB], bunchlast[MAXWALLSB];

static short smost[MAXYSAVES], smostcnt;
static short smoststart[MAXWALLSB];
static char smostwalltype[MAXWALLSB];
static long smostwall[MAXWALLSB], smostwallcnt = -1L;

static short maskwall[MAXWALLSB], maskwallcnt;
static long spritesx[MAXSPRITESONSCREEN];
static long spritesy[MAXSPRITESONSCREEN+1];
static long spritesz[MAXSPRITESONSCREEN];
static spritetype *tspriteptr[MAXSPRITESONSCREEN];

short umost[MAXXDIM], dmost[MAXXDIM];
static short bakumost[MAXXDIM], bakdmost[MAXXDIM];
short uplc[MAXXDIM], dplc[MAXXDIM];
static short uwall[MAXXDIM], dwall[MAXXDIM];
static long swplc[MAXXDIM], lplc[MAXXDIM];
static long swall[MAXXDIM], lwall[MAXXDIM+4];
long xdimen = -1, xdimenrecip, halfxdimen, xdimenscale, xdimscale;
long wx1, wy1, wx2, wy2, ydimen;
long viewoffset, frameoffset;

static long rxi[8], ryi[8], rzi[8], rxi2[8], ryi2[8], rzi2[8];
static long xsi[8], ysi[8];

/* used to be static. --ryan. */
long *horizlookup, *horizlookup2, horizycent;

long globalposx, globalposy, globalposz, globalhoriz;
short globalang, globalcursectnum;
long globalpal, cosglobalang, singlobalang;
long cosviewingrangeglobalang, sinviewingrangeglobalang;
char *globalpalwritten;
long globaluclip, globaldclip, globvis;
long globalvisibility, globalhisibility, globalpisibility, globalcisibility;
char globparaceilclip, globparaflorclip;

long xyaspect, viewingrangerecip;

long asm1, asm2, asm3, asm4;
long vplce[4], vince[4], palookupoffse[4], bufplce[4];
char globalxshift, globalyshift;
long globalxpanning, globalypanning, globalshade;
short globalpicnum, globalshiftval;
long globalzd, globalbufplc, globalyscale, globalorientation;
long globalx1, globaly1, globalx2, globaly2, globalx3, globaly3, globalzx;
long globalx, globaly, globalz;

static short sectorborder[256], sectorbordercnt;
static char tablesloaded = 0;
long pageoffset, ydim16, qsetmode = 0;
long startposx, startposy, startposz;
short startang, startsectnum;
short pointhighlight, linehighlight, highlightcnt;
static long lastx[MAXYDIM];
char *transluc = NULL, paletteloaded = 0;

#define FASTPALGRIDSIZ 8
static long rdist[129], gdist[129], bdist[129];
static char colhere[((FASTPALGRIDSIZ+2)*(FASTPALGRIDSIZ+2)*(FASTPALGRIDSIZ+2))>>3];
static char colhead[(FASTPALGRIDSIZ+2)*(FASTPALGRIDSIZ+2)*(FASTPALGRIDSIZ+2)];
static long colnext[256];
static char coldist[8] = {0,1,2,3,4,3,2,1};
static long colscan[27];

static short clipnum, hitwalls[4];
long hitscangoalx = (1<<29)-1, hitscangoaly = (1<<29)-1;

typedef struct { long x1, y1, x2, y2; } linetype;
static linetype clipit[MAXCLIPNUM];
static short clipsectorlist[MAXCLIPNUM], clipsectnum;
static short clipobjectval[MAXCLIPNUM];

typedef struct
{
	long sx, sy, z;
	short a, picnum;
	signed char dashade;
	unsigned char dapalnum, dastat, pagesleft;
	long cx1, cy1, cx2, cy2;
} permfifotype;
static permfifotype permfifo[MAXPERMS];
static long permhead = 0, permtail = 0;

short numscans, numhits, numbunches;

short editstatus = 0;
short searchit;
long searchx = -1, searchy;                     /* search input  */
short searchsector, searchwall, searchstat;     /* search output */

static char artfilename[20];
static long numtilefiles, artfil = -1, artfilnum, artfilplc;

static char inpreparemirror = 0;
static long mirrorsx1, mirrorsy1, mirrorsx2, mirrorsy2;

long totalclocklock;


/* !!! can we move this somewhere?   --ryan. */
#if ((defined USE_I386_ASM) && (defined __WATCOMC__))
extern long mmxoverlay();
#pragma aux mmxoverlay modify [eax ebx ecx edx];
extern long sethlinesizes(long,long,long);
#pragma aux sethlinesizes parm [eax][ebx][ecx];
extern long setpalookupaddress(char *);
#pragma aux setpalookupaddress parm [eax];
extern long setuphlineasm4(long,long);
#pragma aux setuphlineasm4 parm [eax][ebx];
extern long hlineasm4(long,long,long,long,long,long);
#pragma aux hlineasm4 parm [eax][ebx][ecx][edx][esi][edi];
extern long setuprhlineasm4(long,long,long,long,long,long);
#pragma aux setuprhlineasm4 parm [eax][ebx][ecx][edx][esi][edi];
extern long rhlineasm4(long,long,long,long,long,long);
#pragma aux rhlineasm4 parm [eax][ebx][ecx][edx][esi][edi];
extern long setuprmhlineasm4(long,long,long,long,long,long);
#pragma aux setuprmhlineasm4 parm [eax][ebx][ecx][edx][esi][edi];
extern long rmhlineasm4(long,long,long,long,long,long);
#pragma aux rmhlineasm4 parm [eax][ebx][ecx][edx][esi][edi];
extern long setupqrhlineasm4(long,long,long,long,long,long);
#pragma aux setupqrhlineasm4 parm [eax][ebx][ecx][edx][esi][edi];
extern long qrhlineasm4(long,long,long,long,long,long);
#pragma aux qrhlineasm4 parm [eax][ebx][ecx][edx][esi][edi];
extern long setvlinebpl(long);
#pragma aux setvlinebpl parm [eax];
extern long fixtransluscence(long);
#pragma aux fixtransluscence parm [eax];
extern long prevlineasm1(long,long,long,long,long,long);
#pragma aux prevlineasm1 parm [eax][ebx][ecx][edx][esi][edi];
extern long vlineasm1(long,long,long,long,long,long);
#pragma aux vlineasm1 parm [eax][ebx][ecx][edx][esi][edi];
extern long setuptvlineasm(long);
#pragma aux setuptvlineasm parm [eax];
extern long tvlineasm1(long,long,long,long,long,long);
#pragma aux tvlineasm1 parm [eax][ebx][ecx][edx][esi][edi];
extern long setuptvlineasm2(long,long,long);
#pragma aux setuptvlineasm2 parm [eax][ebx][ecx];
extern long tvlineasm2(long,long,long,long,long,long);
#pragma aux tvlineasm2 parm [eax][ebx][ecx][edx][esi][edi];
extern long mvlineasm1(long,long,long,long,long,long);
#pragma aux mvlineasm1 parm [eax][ebx][ecx][edx][esi][edi];
extern long setupvlineasm(long);
#pragma aux setupvlineasm parm [eax];
extern long vlineasm4(long,long);
#pragma aux vlineasm4 parm [ecx][edi] modify [eax ebx ecx edx esi edi];
extern long setupmvlineasm(long);
#pragma aux setupmvlineasm parm [eax];
extern long mvlineasm4(long,long);
#pragma aux mvlineasm4 parm [ecx][edi] modify [eax ebx ecx edx esi edi];
extern void setupspritevline(long,long,long,long,long,long);
#pragma aux setupspritevline parm [eax][ebx][ecx][edx][esi][edi];
extern void spritevline(long,long,long,long,long,long);
#pragma aux spritevline parm [eax][ebx][ecx][edx][esi][edi];
extern void msetupspritevline(long,long,long,long,long,long);
#pragma aux msetupspritevline parm [eax][ebx][ecx][edx][esi][edi];
extern void mspritevline(long,long,long,long,long,long);
#pragma aux mspritevline parm [eax][ebx][ecx][edx][esi][edi];
extern void tsetupspritevline(long,long,long,long,long,long);
#pragma aux tsetupspritevline parm [eax][ebx][ecx][edx][esi][edi];
extern void tspritevline(long,long,long,long,long,long);
#pragma aux tspritevline parm [eax][ebx][ecx][edx][esi][edi];
extern long mhline(long,long,long,long,long,long);
#pragma aux mhline parm [eax][ebx][ecx][edx][esi][edi];
extern long mhlineskipmodify(long,long,long,long,long,long);
#pragma aux mhlineskipmodify parm [eax][ebx][ecx][edx][esi][edi];
extern long msethlineshift(long,long);
#pragma aux msethlineshift parm [eax][ebx];
extern long thline(long,long,long,long,long,long);
#pragma aux thline parm [eax][ebx][ecx][edx][esi][edi];
extern long thlineskipmodify(long,long,long,long,long,long);
#pragma aux thlineskipmodify parm [eax][ebx][ecx][edx][esi][edi];
extern long tsethlineshift(long,long);
#pragma aux tsethlineshift parm [eax][ebx];
extern long setupslopevlin(long,long,long);
#pragma aux setupslopevlin parm [eax][ebx][ecx] modify [edx];
extern long slopevlin(long,long,long,long,long,long);
#pragma aux slopevlin parm [eax][ebx][ecx][edx][esi][edi];
extern long settransnormal();
#pragma aux settransnormal parm;
extern long settransreverse();
#pragma aux settransreverse parm;
extern long setupdrawslab(long,long);
#pragma aux setupdrawslab parm [eax][ebx];
extern long drawslab(long,long,long,long,long,long);
#pragma aux drawslab parm [eax][ebx][ecx][edx][esi][edi];
#else
#include "a.h"
#endif


#if (defined USE_I386_ASM)
  #if (defined __WATCOMC__)

        long nsqrtasm(int param);
    #pragma aux nsqrtasm =\
	"test eax, 0xff000000",\
	"mov ebx, eax",\
	"jnz short over24",\
	"shr ebx, 12",\
   "mov cx, word ptr shlookup[ebx*2]",\
	"jmp short under24",\
	"over24: shr ebx, 24",\
   "mov cx, word ptr shlookup[ebx*2+8192]",\
	"under24: shr eax, cl",\
	"mov cl, ch",\
	"mov ax, word ptr sqrtable[eax*2]",\
	"shr eax, cl",\
	parm nomemory [eax]\
	modify exact [eax ebx ecx]\

  #elif (defined __GNUC__)
        static long nsqrtasm(int i1)
        {
            long retval;
            __asm__ __volatile__ (
                "\n\t"
            	"testl $0xff000000, %%eax\n\t"
	            "movl %%eax, %%ebx\n\t"
    	        "jnz nsqrover24\n\t"
        	    "shrl $12, %%ebx\n\t"
            	"movw " SYM_shlookup "(, %%ebx, 2), %%cx\n\t"
	            "jmp nsqrunder24\n\t"
        	    "nsqrover24: shr $24, %%ebx\n\t"
    	        "movw (" SYM_shlookup "+ 8192)(, %%ebx, 2), %%cx\n\t"
        	    "nsqrunder24: shrl %%cl, %%eax\n\t"
    	        "movb %%ch, %%cl\n\t"
        	    "movw " SYM_sqrtable "(, %%eax, 2), %%ax\n\t"
    	        "shrl %%cl, %%eax\n\t"
            : "=a" (retval) : "a" (i1) : "ebx", "ecx", "cc");
            return(retval);
        } /* nsqrtasm */

    #else
        #error Please write Assembly code for your platform!
  #endif

#else /* !defined USE_I386_ASM */

        static long nsqrtasm(long eax)
        {
            return((long) sqrt(eax));   /* !!! this might be wrong, due to precision issues. */
        } /* nsqrtasm */

#endif /* defined USE_I386_ASM */