src/rt/rpict.c

/* Copyright (c) 1992 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  rpict.c - routines and variables for picture generation.
 *
 *     8/14/85
 */

#include  "ray.h"

#ifndef NIX
#ifdef BSD
#include  <sys/time.h>
#include  <sys/resource.h>
#else
#include  <sys/types.h>
#include  <sys/times.h>
#include  <limits.h>
extern time_t   time();
#endif
#else
extern unsigned long    time();
#endif

#include  <signal.h>

#include  "view.h"

#include  "resolu.h"

#include  "random.h"

#include  "paths.h"

#define  RFTEMPLATE     "rfXXXXXX"

#ifndef SIGCONT
#define SIGCONT         SIGIO
#endif

int  dimlist[MAXDIM];                   /* sampling dimensions */
int  ndims = 0;                         /* number of sampling dimensions */
int  samplendx;                         /* sample index number */

VIEW  ourview = STDVIEW;                /* view parameters */
int  hresolu = 512;                     /* horizontal resolution */
int  vresolu = 512;                     /* vertical resolution */
double  pixaspect = 1.0;                /* pixel aspect ratio */

int  psample = 4;                       /* pixel sample size */
double  maxdiff = .05;                  /* max. difference for interpolation */
double  dstrpix = 0.67;                 /* square pixel distribution */

double  dstrsrc = 0.0;                  /* square source distribution */
double  shadthresh = .05;               /* shadow threshold */
double  shadcert = .5;                  /* shadow certainty */
int  directrelay = 1;                   /* number of source relays */
int  vspretest = 512;                   /* virtual source pretest density */
int  directvis = 1;                     /* sources visible? */
double  srcsizerat = .25;               /* maximum ratio source size/dist. */

double  specthresh = .15;               /* specular sampling threshold */
double  specjitter = 1.;                /* specular sampling jitter */

int  maxdepth = 6;                      /* maximum recursion depth */
double  minweight = 5e-3;               /* minimum ray weight */

COLOR  ambval = BLKCOLOR;               /* ambient value */
double  ambacc = 0.2;                   /* ambient accuracy */
int  ambres = 32;                       /* ambient resolution */
int  ambdiv = 128;                      /* ambient divisions */
int  ambssamp = 0;                      /* ambient super-samples */
int  ambounce = 0;                      /* ambient bounces */
char  *amblist[128];                    /* ambient include/exclude list */
int  ambincl = -1;                      /* include == 1, exclude == 0 */

#ifdef MSDOS
int  ralrm = 60;                        /* seconds between reports */
#else
int  ralrm = 0;                         /* seconds between reports */
#endif

double  pctdone = 0.0;                  /* percentage done */

unsigned long  tlastrept = 0L;          /* time at last report */

extern unsigned long  tstart;           /* starting time */

extern unsigned long  nrays;            /* number of rays traced */

#define  MAXDIV         16              /* maximum sample size */

#define  pixjitter()    (.5+dstrpix*(.5-frandom()))

static int  hres, vres;                 /* resolution for this frame */

extern char  *mktemp();

double  pixvalue();

#ifdef NIX
#define  file_exists(f) (access(f,F_OK)==0)
#else
#include  <sys/types.h>
#include  <sys/stat.h>
int
file_exists(fname)                              /* ordinary file exists? */
char  *fname;
{
        struct stat  sbuf;
        if (stat(fname, &sbuf) < 0) return(0);
        return((sbuf.st_mode & S_IFREG) != 0);
}
#endif


quit(code)                      /* quit program */
int  code;
{
        if (code)                       /* report status */
                report();
        headclean();                    /* delete header file */
        pfclean();                      /* clean up persist files */
        exit(code);
}


#ifndef NIX
report()                /* report progress */
{
        char  hostname[128];
        double  u, s;
#ifdef BSD
        struct rusage  rubuf;
#else
        struct tms  tbuf;
#endif

        tlastrept = time((unsigned long *)NULL);
#ifdef BSD
        getrusage(RUSAGE_SELF, &rubuf);
        u = rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6;
        s = rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6;
        getrusage(RUSAGE_CHILDREN, &rubuf);
        u += rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6;
        s += rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6;
#else
        times(&tbuf);
        u = ( tbuf.tms_utime + tbuf.tms_cutime ) / CLK_TCK;
        s = ( tbuf.tms_stime + tbuf.tms_cstime ) / CLK_TCK;
#endif
        gethostname(hostname, sizeof(hostname));

        sprintf(errmsg,
                "%lu rays, %4.2f%% after %.3fu %.3fs %.3fr hours on %s\n",
                        nrays, pctdone, u/3600., s/3600.,
                        (tlastrept-tstart)/3600., hostname);
        eputs(errmsg);
}
#else
report()                /* report progress */
{
        tlastrept = time((unsigned long *)NULL);
        sprintf(errmsg, "%lu rays, %4.2f%% after %5.4f hours\n",
                        nrays, pctdone, (tlastrept-tstart)/3600.0);
        eputs(errmsg);
        signal(SIGCONT, report);
}
#endif


rpict(seq, pout, zout, prvr)                    /* generate image(s) */
int  seq;
char  *pout, *zout, *prvr;
/*
 * If seq is greater than zero, then we will render a sequence of
 * images based on view parameter strings read from the standard input.
 * If pout is NULL, then all images will be sent to the standard ouput.
 * If seq is greater than zero and prvr is an integer, then it is the
 * frame number at which rendering should begin.  Preceeding view parameter
 * strings will be skipped in the input.
 * If pout and prvr are the same, prvr is renamed to avoid overwriting.
 * Note that pout and zout should contain %d format specifications for
 * sequenced file naming.
 */
{
        extern char  *rindex(), *strncpy(), *strcat(), *strcpy();
        char  fbuf[128], fbuf2[128];
        int  npicts;
        register char  *cp;
        RESOLU  rs;
        double  pa;
                                        /* check sampling */
        if (psample < 1)
                psample = 1;
        else if (psample > MAXDIV) {
                sprintf(errmsg, "pixel sampling reduced from %d to %d",
                                psample, MAXDIV);
                error(WARNING, errmsg);
                psample = MAXDIV;
        }
                                        /* get starting frame */
        if (seq <= 0)
                seq = 0;
        else if (prvr != NULL && isint(prvr)) {
                register int  rn;               /* skip to specified view */
                if ((rn = atoi(prvr)) < seq)
                        error(USER, "recover frame less than start frame");
                if (pout == NULL)
                        error(USER, "missing output file specification");
                for ( ; seq < rn; seq++)
                        if (nextview(stdin) == EOF)
                                error(USER, "unexpected EOF on view input");
                prvr = fbuf;                    /* mark for renaming */
        }
        if (pout != NULL & prvr != NULL) {
                sprintf(fbuf, pout, seq);
                if (!strcmp(prvr, fbuf)) {      /* rename */
                        strcpy(fbuf2, fbuf);
                        for (cp = fbuf2; *cp; cp++)
                                ;
                        while (cp > fbuf2 && !ISDIRSEP(cp[-1]))
                                cp--;
                        strcpy(cp, RFTEMPLATE);
                        prvr = mktemp(fbuf2);
                        if (rename(fbuf, prvr) < 0)
                                if (errno == ENOENT) {  /* ghost file */
                                        sprintf(errmsg,
                                                "new output file \"%s\"",
                                                fbuf);
                                        error(WARNING, errmsg);
                                        prvr = NULL;
                                } else {                /* serious error */
                                        sprintf(errmsg,
                                        "cannot rename \"%s\" to \"%s\"",
                                                fbuf, prvr);
                                        error(SYSTEM, errmsg);
                                }
                }
        }
        npicts = 0;                     /* render sequence */
        do {
                if (seq && nextview(stdin) == EOF)
                        break;
                pctdone = 0.0;
                if (pout != NULL) {
                        sprintf(fbuf, pout, seq);
                        if (file_exists(fbuf)) {
                                if (prvr != NULL || !strcmp(fbuf, pout)) {
                                        sprintf(errmsg,
                                                "output file \"%s\" exists",
                                                fbuf);
                                        error(USER, errmsg);
                                }
                                continue;               /* don't clobber */
                        }
                        if (freopen(fbuf, "w", stdout) == NULL) {
                                sprintf(errmsg,
                                        "cannot open output file \"%s\"", fbuf);
                                error(SYSTEM, errmsg);
                        }
#ifdef MSDOS
                        setmode(fileno(stdout), O_BINARY);
#endif
                        dupheader();
                }
                hres = hresolu; vres = vresolu; pa = pixaspect;
                if (prvr != NULL)
                        if (viewfile(prvr, &ourview, &rs) <= 0
                                        || rs.or != PIXSTANDARD) {
                                sprintf(errmsg,
                        "cannot recover view parameters from \"%s\"", prvr);
                                error(WARNING, errmsg);
                        } else {
                                pa = 0.0;
                                hres = scanlen(&rs);
                                vres = numscans(&rs);
                        }
                if ((cp = setview(&ourview)) != NULL)
                        error(USER, cp);
                normaspect(viewaspect(&ourview), &pa, &hres, &vres);
                if (seq) {
                        if (ralrm > 0) {
                                fprintf(stderr, "FRAME %d:", seq);
                                fprintview(&ourview, stderr);
                                putc('\n', stderr);
                                fflush(stderr);
                        }
                        printf("FRAME=%d\n", seq);
                }
                fputs(VIEWSTR, stdout);
                fprintview(&ourview, stdout);
                putchar('\n');
                if (pa < .99 || pa > 1.01)
                        fputaspect(pa, stdout);
                fputformat(COLRFMT, stdout);
                putchar('\n');
                if (zout != NULL)
                        sprintf(cp=fbuf, zout, seq);
                else
                        cp = NULL;
                render(cp, prvr);
                prvr = NULL;
                npicts++;
        } while (seq++);
                                        /* check that we did something */
        if (npicts == 0)
                error(WARNING, "no output produced");
}


nextview(fp)                            /* get next view from fp */
FILE  *fp;
{
        char  linebuf[256];

        while (fgets(linebuf, sizeof(linebuf), fp) != NULL)
                if (isview(linebuf) && sscanview(&ourview, linebuf) > 0)
                        return(0);
        return(EOF);
}       


render(zfile, oldfile)                          /* render the scene */
char  *zfile, *oldfile;
{
        extern long  lseek();
        COLOR  *scanbar[MAXDIV+1];      /* scanline arrays of pixel values */
        float  *zbar[MAXDIV+1];         /* z values */
        char  *sampdens;                /* previous sample density */
        int  ypos;                      /* current scanline */
        int  ystep;                     /* current y step size */
        int  hstep;                     /* h step size */
        int  zfd;
        COLOR  *colptr;
        float  *zptr;
        register int  i;
                                        /* allocate scanlines */
        for (i = 0; i <= psample; i++) {
                scanbar[i] = (COLOR *)malloc(hres*sizeof(COLOR));
                if (scanbar[i] == NULL)
                        goto memerr;
        }
        hstep = (psample*140+49)/99;            /* quincunx sampling */
        ystep = (psample*99+70)/140;
        if (hstep > 2) {
                i = hres/hstep + 2;
                if ((sampdens = malloc(i)) == NULL)
                        goto memerr;
                while (i--)
                        sampdens[i] = hstep;
        } else
                sampdens = NULL;
                                        /* open z-file */
        if (zfile != NULL) {
                if ((zfd = open(zfile, O_WRONLY|O_CREAT, 0666)) == -1) {
                        sprintf(errmsg, "cannot open z-file \"%s\"", zfile);
                        error(SYSTEM, errmsg);
                }
#ifdef MSDOS
                setmode(zfd, O_BINARY);
#endif
                for (i = 0; i <= psample; i++) {
                        zbar[i] = (float *)malloc(hres*sizeof(float));
                        if (zbar[i] == NULL)
                                goto memerr;
                }
        } else {
                zfd = -1;
                for (i = 0; i <= psample; i++)
                        zbar[i] = NULL;
        }
                                        /* write out boundaries */
        fprtresolu(hres, vres, stdout);
                                        /* recover file and compute first */
        i = salvage(oldfile);
        if (zfd != -1 && i > 0 &&
                        lseek(zfd, (long)i*hres*sizeof(float), 0) == -1)
                error(SYSTEM, "z-file seek error in render");
        pctdone = 100.0*i/vres;
        if (ralrm > 0)                  /* report init stats */
                report();
#ifndef  BSD
        else
#endif
        signal(SIGCONT, report);
        ypos = vres-1 - i;
        fillscanline(scanbar[0], zbar[0], sampdens, hres, ypos, hstep);
                                                /* compute scanlines */
        for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
                                                        /* bottom adjust? */
                if (ypos < 0) {
                        ystep += ypos;
                        ypos = 0;
                }
                colptr = scanbar[ystep];                /* move base to top */
                scanbar[ystep] = scanbar[0];
                scanbar[0] = colptr;
                zptr = zbar[ystep];
                zbar[ystep] = zbar[0];
                zbar[0] = zptr;
                                                        /* fill base line */
                fillscanline(scanbar[0], zbar[0], sampdens,
                                hres, ypos, hstep);
                                                        /* fill bar */
                fillscanbar(scanbar, zbar, hres, ypos, ystep);
                                                        /* write it out */
#ifndef  BSD
                signal(SIGCONT, SIG_IGN);       /* don't interrupt writes */
#endif
                for (i = ystep; i > 0; i--) {
                        if (zfd != -1 && write(zfd, (char *)zbar[i],
                                        hres*sizeof(float))
                                        < hres*sizeof(float))
                                goto writerr;
                        if (fwritescan(scanbar[i], hres, stdout) < 0)
                                goto writerr;
                }
                if (fflush(stdout) == EOF)
                        goto writerr;
                                                        /* record progress */
                pctdone = 100.0*(vres-1-ypos)/vres;
                if (ralrm > 0 && time((unsigned long *)NULL) >= tlastrept+ralrm)
                        report();
#ifndef  BSD
                else
                        signal(SIGCONT, report);
#endif
        }
                                                /* clean up */
        signal(SIGCONT, SIG_IGN);
        if (zfd != -1) {
                if (write(zfd, (char *)zbar[0], hres*sizeof(float))
                                < hres*sizeof(float))
                        goto writerr;
                if (close(zfd) == -1)
                        goto writerr;
                for (i = 0; i <= psample; i++)
                        free((char *)zbar[i]);
        }
        fwritescan(scanbar[0], hres, stdout);
        if (fflush(stdout) == EOF)
                goto writerr;
        for (i = 0; i <= psample; i++)
                free((char *)scanbar[i]);
        if (sampdens != NULL)
                free(sampdens);
        pctdone = 100.0;
        if (ralrm > 0)
                report();
        signal(SIGCONT, SIG_DFL);
        return;
writerr:
        error(SYSTEM, "write error in render");
memerr:
        error(SYSTEM, "out of memory in render");
}


fillscanline(scanline, zline, sd, xres, y, xstep)       /* fill scan at y */
register COLOR  *scanline;
register float  *zline;
register char  *sd;
int  xres, y, xstep;
{
        static int  nc = 0;             /* number of calls */
        int  bl = xstep, b = xstep;
        double  z;
        register int  i;
        
        z = pixvalue(scanline[0], 0, y);
        if (zline) zline[0] = z;
                                /* zig-zag start for quincunx pattern */
        for (i = ++nc & 1 ? xstep : xstep/2; i < xres-1+xstep; i += xstep) {
                if (i >= xres) {
                        xstep += xres-1-i;
                        i = xres-1;
                }
                z = pixvalue(scanline[i], i, y);
                if (zline) zline[i] = z;
                if (sd) b = sd[0] > sd[1] ? sd[0] : sd[1];
                if (i <= xstep)
                        b = fillsample(scanline, zline, 0, y, i, 0, b/2);
                else
                        b = fillsample(scanline+i-xstep,
                                        zline ? zline+i-xstep : NULL,
                                        i-xstep, y, xstep, 0, b/2);
                if (sd) *sd++ = nc & 1 ? bl : b;
                bl = b;
        }
        if (sd && nc & 1) *sd = bl;
}


fillscanbar(scanbar, zbar, xres, y, ysize)      /* fill interior */
register COLOR  *scanbar[];
register float  *zbar[];
int  xres, y, ysize;
{
        COLOR  vline[MAXDIV+1];
        float  zline[MAXDIV+1];
        int  b = ysize;
        register int  i, j;
        
        for (i = 0; i < xres; i++) {
                
                copycolor(vline[0], scanbar[0][i]);
                copycolor(vline[ysize], scanbar[ysize][i]);
                if (zbar[0]) {
                        zline[0] = zbar[0][i];
                        zline[ysize] = zbar[ysize][i];
                }
                
                b = fillsample(vline, zbar[0] ? zline : NULL,
                                i, y, 0, ysize, b/2);
                
                for (j = 1; j < ysize; j++)
                        copycolor(scanbar[j][i], vline[j]);
                if (zbar[0])
                        for (j = 1; j < ysize; j++)
                                zbar[j][i] = zline[j];
        }
}


int
fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
register COLOR  *colline;
register float  *zline;
int  x, y;
int  xlen, ylen;
int  b;
{
        double  ratio;
        double  z;
        COLOR  ctmp;
        int  ncut;
        register int  len;
        
        if (xlen > 0)                   /* x or y length is zero */
                len = xlen;
        else
                len = ylen;
                
        if (len <= 1)                   /* limit recursion */
                return(0);
        
        if (b > 0
        || (zline && 2.*fabs(zline[0]-zline[len]) > maxdiff*(zline[0]+zline[len]))
                        || bigdiff(colline[0], colline[len], maxdiff)) {
        
                z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
                if (zline) zline[len>>1] = z;
                ncut = 1;
                
        } else {                                        /* interpolate */
        
                copycolor(colline[len>>1], colline[len]);
                ratio = (double)(len>>1) / len;
                scalecolor(colline[len>>1], ratio);
                if (zline) zline[len>>1] = zline[len] * ratio;
                ratio = 1.0 - ratio;
                copycolor(ctmp, colline[0]);
                scalecolor(ctmp, ratio);
                addcolor(colline[len>>1], ctmp);
                if (zline) zline[len>>1] += zline[0] * ratio;
                ncut = 0;
        }
                                                        /* recurse */
        ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
        
        ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
                        x+(xlen>>1), y+(ylen>>1),
                        xlen-(xlen>>1), ylen-(ylen>>1), b/2);

        return(ncut);
}


double
pixvalue(col, x, y)             /* compute pixel value */
COLOR  col;                     /* returned color */
int  x, y;                      /* pixel position */
{
        static RAY  thisray;

        if (viewray(thisray.rorg, thisray.rdir, &ourview,
                        (x+pixjitter())/hres, (y+pixjitter())/vres) < 0) {
                setcolor(col, 0.0, 0.0, 0.0);
                return(0.0);
        }

        rayorigin(&thisray, NULL, PRIMARY, 1.0);

        samplendx = pixnumber(x,y,hres,vres);   /* set pixel index */

        rayvalue(&thisray);                     /* trace ray */

        copycolor(col, thisray.rcol);           /* return color */
        
        return(thisray.rt);                     /* return distance */
}


int
salvage(oldfile)                /* salvage scanlines from killed program */
char  *oldfile;
{
        COLR  *scanline;
        FILE  *fp;
        int  x, y;

        if (oldfile == NULL)
                return(0);
        
        if ((fp = fopen(oldfile, "r")) == NULL) {
                sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
                error(WARNING, errmsg);
                return(0);
        }
#ifdef MSDOS
        setmode(fileno(fp), O_BINARY);
#endif
                                /* discard header */
        getheader(fp, NULL, NULL);
                                /* get picture size */
        if (!fscnresolu(&x, &y, fp)) {
                sprintf(errmsg, "bad recover file \"%s\" - not removed",
                                oldfile);
                error(WARNING, errmsg);
                fclose(fp);
                return(0);
        }

        if (x != hres || y != vres) {
                sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
                                oldfile);
                error(USER, errmsg);
        }

        scanline = (COLR *)malloc(hres*sizeof(COLR));
        if (scanline == NULL)
                error(SYSTEM, "out of memory in salvage");
        for (y = 0; y < vres; y++) {
                if (freadcolrs(scanline, hres, fp) < 0)
                        break;
                if (fwritecolrs(scanline, hres, stdout) < 0)
                        goto writerr;
        }
        if (fflush(stdout) == EOF)
                goto writerr;
        free((char *)scanline);
        fclose(fp);
        unlink(oldfile);
        return(y);
writerr:
        sprintf(errmsg, "write error during recovery of \"%s\"", oldfile);
        error(SYSTEM, errmsg);
}


int
pixnumber(x, y, xres, yres)             /* compute pixel index (brushed) */
register int  x, y;
int  xres, yres;
{
        x -= y;
        while (x < 0)
                x += xres;
        return((((x>>2)*yres + y) << 2) + (x & 3));
}
Revision:	2.31
Committed:	Thu Nov 18 09:22:55 1993 UTC (30 years, 5 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.30:	+8 -6 lines
Log Message:	fixed time declaration and use
#	User	Rev	Content
1	greg	2.8	/* Copyright (c) 1992 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* rpict.c - routines and variables for picture generation.
9			*
10			* 8/14/85
11			*/
12
13			#include "ray.h"
14
15	greg	2.30	#ifndef NIX
16	greg	1.1	#ifdef BSD
17			#include <sys/time.h>
18			#include <sys/resource.h>
19	greg	2.30	#else
20			#include <sys/types.h>
21			#include <sys/times.h>
22			#include <limits.h>
23	greg	2.31	extern time_t time();
24	greg	1.34	#endif
25	greg	2.31	#else
26			extern unsigned long time();
27	greg	2.30	#endif
28	greg	1.34
29	greg	1.14	#include <signal.h>
30	greg	1.1
31			#include "view.h"
32
33	greg	1.36	#include "resolu.h"
34
35	greg	1.1	#include "random.h"
36
37	greg	2.12	#include "paths.h"
38
39	greg	2.21	#define RFTEMPLATE "rfXXXXXX"
40
41	greg	2.22	#ifndef SIGCONT
42			#define SIGCONT SIGIO
43			#endif
44
45	greg	1.25	int dimlist[MAXDIM]; /* sampling dimensions */
46			int ndims = 0; /* number of sampling dimensions */
47			int samplendx; /* sample index number */
48
49	greg	1.12	VIEW ourview = STDVIEW; /* view parameters */
50			int hresolu = 512; /* horizontal resolution */
51			int vresolu = 512; /* vertical resolution */
52	greg	2.14	double pixaspect = 1.0; /* pixel aspect ratio */
53	greg	1.1
54			int psample = 4; /* pixel sample size */
55	greg	2.14	double maxdiff = .05; /* max. difference for interpolation */
56			double dstrpix = 0.67; /* square pixel distribution */
57	greg	1.1
58	greg	2.14	double dstrsrc = 0.0; /* square source distribution */
59			double shadthresh = .05; /* shadow threshold */
60			double shadcert = .5; /* shadow certainty */
61	greg	1.35	int directrelay = 1; /* number of source relays */
62	greg	1.29	int vspretest = 512; /* virtual source pretest density */
63	greg	2.20	int directvis = 1; /* sources visible? */
64	greg	2.14	double srcsizerat = .25; /* maximum ratio source size/dist. */
65	greg	1.1
66	greg	2.14	double specthresh = .15; /* specular sampling threshold */
67			double specjitter = 1.; /* specular sampling jitter */
68	greg	2.5
69	greg	1.1	int maxdepth = 6; /* maximum recursion depth */
70	greg	2.14	double minweight = 5e-3; /* minimum ray weight */
71	greg	1.1
72			COLOR ambval = BLKCOLOR; /* ambient value */
73	greg	2.14	double ambacc = 0.2; /* ambient accuracy */
74	greg	1.6	int ambres = 32; /* ambient resolution */
75	greg	1.1	int ambdiv = 128; /* ambient divisions */
76			int ambssamp = 0; /* ambient super-samples */
77			int ambounce = 0; /* ambient bounces */
78			char amblist[128]; / ambient include/exclude list */
79			int ambincl = -1; /* include == 1, exclude == 0 */
80
81	greg	2.16	#ifdef MSDOS
82			int ralrm = 60; /* seconds between reports */
83			#else
84	greg	1.1	int ralrm = 0; /* seconds between reports */
85	greg	2.16	#endif
86	greg	1.1
87	greg	2.14	double pctdone = 0.0; /* percentage done */
88	greg	1.1
89	greg	2.31	unsigned long tlastrept = 0L; /* time at last report */
90	greg	1.24
91	greg	2.31	extern unsigned long tstart; /* starting time */
92	greg	1.24
93	greg	2.24	extern unsigned long nrays; /* number of rays traced */
94	greg	1.1
95	greg	2.14	#define MAXDIV 16 /* maximum sample size */
96	greg	1.1
97	greg	2.14	#define pixjitter() (.5+dstrpix*(.5-frandom()))
98	greg	1.1
99	greg	2.8	static int hres, vres; /* resolution for this frame */
100
101			extern char *mktemp();
102
103	greg	2.14	double pixvalue();
104	greg	1.1
105	greg	2.27	#ifdef NIX
106			#define file_exists(f) (access(f,F_OK)==0)
107			#else
108			#include <sys/types.h>
109			#include <sys/stat.h>
110			int
111			file_exists(fname) /* ordinary file exists? */
112			char *fname;
113			{
114			struct stat sbuf;
115			if (stat(fname, &sbuf) < 0) return(0);
116			return((sbuf.st_mode & S_IFREG) != 0);
117			}
118			#endif
119	greg	1.11
120	greg	2.27
121	greg	1.1	quit(code) /* quit program */
122			int code;
123			{
124	greg	2.8	if (code) /* report status */
125	greg	1.1	report();
126	greg	2.21	headclean(); /* delete header file */
127			pfclean(); /* clean up persist files */
128	greg	1.1	exit(code);
129			}
130
131
132	greg	2.30	#ifndef NIX
133	greg	1.1	report() /* report progress */
134			{
135	greg	2.30	char hostname[128];
136			double u, s;
137			#ifdef BSD
138	greg	1.1	struct rusage rubuf;
139	greg	2.30	#else
140			struct tms tbuf;
141			#endif
142	greg	1.1
143	greg	2.31	tlastrept = time((unsigned long *)NULL);
144	greg	2.30	#ifdef BSD
145	greg	1.1	getrusage(RUSAGE_SELF, &rubuf);
146	greg	2.30	u = rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6;
147			s = rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6;
148	greg	1.1	getrusage(RUSAGE_CHILDREN, &rubuf);
149	greg	2.30	u += rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6;
150			s += rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6;
151			#else
152			times(&tbuf);
153			u = ( tbuf.tms_utime + tbuf.tms_cutime ) / CLK_TCK;
154			s = ( tbuf.tms_stime + tbuf.tms_cstime ) / CLK_TCK;
155			#endif
156			gethostname(hostname, sizeof(hostname));
157	greg	1.1
158	greg	2.30	sprintf(errmsg,
159			"%lu rays, %4.2f%% after %.3fu %.3fs %.3fr hours on %s\n",
160			nrays, pctdone, u/3600., s/3600.,
161			(tlastrept-tstart)/3600., hostname);
162	greg	1.24	eputs(errmsg);
163			}
164	greg	1.1	#else
165	greg	1.24	report() /* report progress */
166			{
167	greg	2.31	tlastrept = time((unsigned long *)NULL);
168	greg	2.30	sprintf(errmsg, "%lu rays, %4.2f%% after %5.4f hours\n",
169	greg	1.24	nrays, pctdone, (tlastrept-tstart)/3600.0);
170	greg	1.1	eputs(errmsg);
171	greg	2.22	signal(SIGCONT, report);
172	greg	1.1	}
173	greg	1.24	#endif
174	greg	1.1
175
176	greg	2.8	rpict(seq, pout, zout, prvr) /* generate image(s) */
177			int seq;
178			char pout, zout, *prvr;
179			/*
180			* If seq is greater than zero, then we will render a sequence of
181			* images based on view parameter strings read from the standard input.
182			* If pout is NULL, then all images will be sent to the standard ouput.
183			* If seq is greater than zero and prvr is an integer, then it is the
184			* frame number at which rendering should begin. Preceeding view parameter
185			* strings will be skipped in the input.
186			* If pout and prvr are the same, prvr is renamed to avoid overwriting.
187			* Note that pout and zout should contain %d format specifications for
188			* sequenced file naming.
189			*/
190			{
191	greg	2.21	extern char rindex(), strncpy(), strcat(), strcpy();
192	greg	2.9	char fbuf[128], fbuf2[128];
193	greg	2.26	int npicts;
194	greg	2.9	register char *cp;
195	greg	2.14	RESOLU rs;
196			double pa;
197	greg	2.8	/* check sampling */
198			if (psample < 1)
199			psample = 1;
200			else if (psample > MAXDIV) {
201			sprintf(errmsg, "pixel sampling reduced from %d to %d",
202			psample, MAXDIV);
203			error(WARNING, errmsg);
204			psample = MAXDIV;
205			}
206			/* get starting frame */
207			if (seq <= 0)
208			seq = 0;
209			else if (prvr != NULL && isint(prvr)) {
210	greg	2.9	register int rn; /* skip to specified view */
211	greg	2.8	if ((rn = atoi(prvr)) < seq)
212			error(USER, "recover frame less than start frame");
213			if (pout == NULL)
214			error(USER, "missing output file specification");
215			for ( ; seq < rn; seq++)
216			if (nextview(stdin) == EOF)
217			error(USER, "unexpected EOF on view input");
218			prvr = fbuf; /* mark for renaming */
219			}
220	greg	2.18	if (pout != NULL & prvr != NULL) {
221	greg	2.8	sprintf(fbuf, pout, seq);
222	greg	2.18	if (!strcmp(prvr, fbuf)) { /* rename */
223			strcpy(fbuf2, fbuf);
224			for (cp = fbuf2; *cp; cp++)
225			;
226			while (cp > fbuf2 && !ISDIRSEP(cp[-1]))
227			cp--;
228			strcpy(cp, RFTEMPLATE);
229	greg	2.8	prvr = mktemp(fbuf2);
230	greg	2.28	if (rename(fbuf, prvr) < 0)
231			if (errno == ENOENT) { /* ghost file */
232			sprintf(errmsg,
233			"new output file \"%s\"",
234			fbuf);
235			error(WARNING, errmsg);
236			prvr = NULL;
237			} else { /* serious error */
238			sprintf(errmsg,
239	greg	2.8	"cannot rename \"%s\" to \"%s\"",
240			fbuf, prvr);
241	greg	2.28	error(SYSTEM, errmsg);
242			}
243	greg	2.8	}
244			}
245	greg	2.26	npicts = 0; /* render sequence */
246	greg	2.8	do {
247			if (seq && nextview(stdin) == EOF)
248			break;
249	greg	2.25	pctdone = 0.0;
250	greg	2.8	if (pout != NULL) {
251			sprintf(fbuf, pout, seq);
252	greg	2.27	if (file_exists(fbuf)) {
253			if (prvr != NULL \|\| !strcmp(fbuf, pout)) {
254			sprintf(errmsg,
255			"output file \"%s\" exists",
256			fbuf);
257			error(USER, errmsg);
258			}
259	greg	2.26	continue; /* don't clobber */
260	greg	2.27	}
261	greg	2.8	if (freopen(fbuf, "w", stdout) == NULL) {
262			sprintf(errmsg,
263			"cannot open output file \"%s\"", fbuf);
264			error(SYSTEM, errmsg);
265			}
266	greg	2.17	#ifdef MSDOS
267			setmode(fileno(stdout), O_BINARY);
268			#endif
269	greg	2.8	dupheader();
270			}
271			hres = hresolu; vres = vresolu; pa = pixaspect;
272			if (prvr != NULL)
273			if (viewfile(prvr, &ourview, &rs) <= 0
274			\|\| rs.or != PIXSTANDARD) {
275			sprintf(errmsg,
276			"cannot recover view parameters from \"%s\"", prvr);
277			error(WARNING, errmsg);
278			} else {
279			pa = 0.0;
280			hres = scanlen(&rs);
281			vres = numscans(&rs);
282			}
283	greg	2.9	if ((cp = setview(&ourview)) != NULL)
284			error(USER, cp);
285	greg	2.8	normaspect(viewaspect(&ourview), &pa, &hres, &vres);
286			if (seq) {
287			if (ralrm > 0) {
288	greg	2.11	fprintf(stderr, "FRAME %d:", seq);
289			fprintview(&ourview, stderr);
290			putc('\n', stderr);
291			fflush(stderr);
292	greg	2.8	}
293			printf("FRAME=%d\n", seq);
294			}
295			fputs(VIEWSTR, stdout);
296			fprintview(&ourview, stdout);
297			putchar('\n');
298			if (pa < .99 \|\| pa > 1.01)
299			fputaspect(pa, stdout);
300			fputformat(COLRFMT, stdout);
301			putchar('\n');
302			if (zout != NULL)
303	greg	2.9	sprintf(cp=fbuf, zout, seq);
304	greg	2.8	else
305	greg	2.9	cp = NULL;
306			render(cp, prvr);
307	greg	2.8	prvr = NULL;
308	greg	2.26	npicts++;
309	greg	2.8	} while (seq++);
310	greg	2.26	/* check that we did something */
311			if (npicts == 0)
312			error(WARNING, "no output produced");
313	greg	2.8	}
314
315
316			nextview(fp) /* get next view from fp */
317			FILE *fp;
318			{
319	greg	2.9	char linebuf[256];
320	greg	2.8
321			while (fgets(linebuf, sizeof(linebuf), fp) != NULL)
322	greg	2.9	if (isview(linebuf) && sscanview(&ourview, linebuf) > 0)
323	greg	2.8	return(0);
324			return(EOF);
325			}
326
327
328	greg	1.11	render(zfile, oldfile) /* render the scene */
329			char zfile, oldfile;
330	greg	1.1	{
331	greg	1.16	extern long lseek();
332	greg	1.1	COLOR scanbar[MAXDIV+1]; / scanline arrays of pixel values */
333	greg	1.11	float zbar[MAXDIV+1]; / z values */
334	greg	2.2	char sampdens; / previous sample density */
335	greg	1.1	int ypos; /* current scanline */
336	greg	1.15	int ystep; /* current y step size */
337	greg	1.33	int hstep; /* h step size */
338	greg	1.16	int zfd;
339	greg	1.1	COLOR *colptr;
340	greg	1.11	float *zptr;
341	greg	1.1	register int i;
342	greg	1.9	/* allocate scanlines */
343	greg	1.1	for (i = 0; i <= psample; i++) {
344	greg	2.8	scanbar[i] = (COLOR )malloc(hressizeof(COLOR));
345	greg	1.1	if (scanbar[i] == NULL)
346	greg	1.11	goto memerr;
347	greg	1.1	}
348	greg	2.2	hstep = (psample140+49)/99; / quincunx sampling */
349			ystep = (psample*99+70)/140;
350			if (hstep > 2) {
351	greg	2.8	i = hres/hstep + 2;
352	greg	2.2	if ((sampdens = malloc(i)) == NULL)
353			goto memerr;
354			while (i--)
355			sampdens[i] = hstep;
356			} else
357			sampdens = NULL;
358	greg	2.26	/* open z-file */
359	greg	1.11	if (zfile != NULL) {
360	greg	1.16	if ((zfd = open(zfile, O_WRONLY\|O_CREAT, 0666)) == -1) {
361	greg	2.26	sprintf(errmsg, "cannot open z-file \"%s\"", zfile);
362	greg	1.11	error(SYSTEM, errmsg);
363			}
364	greg	2.17	#ifdef MSDOS
365			setmode(zfd, O_BINARY);
366			#endif
367	greg	1.11	for (i = 0; i <= psample; i++) {
368	greg	2.8	zbar[i] = (float )malloc(hressizeof(float));
369	greg	1.11	if (zbar[i] == NULL)
370			goto memerr;
371			}
372			} else {
373	greg	1.16	zfd = -1;
374	greg	1.11	for (i = 0; i <= psample; i++)
375			zbar[i] = NULL;
376			}
377	greg	1.1	/* write out boundaries */
378	greg	2.8	fprtresolu(hres, vres, stdout);
379	greg	1.10	/* recover file and compute first */
380	greg	1.11	i = salvage(oldfile);
381	greg	1.23	if (zfd != -1 && i > 0 &&
382	greg	2.8	lseek(zfd, (long)ihressizeof(float), 0) == -1)
383	greg	2.26	error(SYSTEM, "z-file seek error in render");
384	greg	2.8	pctdone = 100.0*i/vres;
385	greg	1.24	if (ralrm > 0) /* report init stats */
386			report();
387	greg	2.14	#ifndef BSD
388	greg	1.32	else
389			#endif
390	greg	2.22	signal(SIGCONT, report);
391	greg	2.8	ypos = vres-1 - i;
392			fillscanline(scanbar[0], zbar[0], sampdens, hres, ypos, hstep);
393	greg	1.10	/* compute scanlines */
394	greg	1.15	for (ypos -= ystep; ypos > -ystep; ypos -= ystep) {
395			/* bottom adjust? */
396			if (ypos < 0) {
397			ystep += ypos;
398			ypos = 0;
399			}
400			colptr = scanbar[ystep]; /* move base to top */
401			scanbar[ystep] = scanbar[0];
402	greg	1.1	scanbar[0] = colptr;
403	greg	1.15	zptr = zbar[ystep];
404			zbar[ystep] = zbar[0];
405	greg	1.11	zbar[0] = zptr;
406	greg	1.10	/* fill base line */
407	greg	2.2	fillscanline(scanbar[0], zbar[0], sampdens,
408	greg	2.8	hres, ypos, hstep);
409	greg	1.10	/* fill bar */
410	greg	2.8	fillscanbar(scanbar, zbar, hres, ypos, ystep);
411	greg	1.10	/* write it out */
412	greg	2.14	#ifndef BSD
413	greg	2.22	signal(SIGCONT, SIG_IGN); /* don't interrupt writes */
414	greg	1.32	#endif
415	greg	1.15	for (i = ystep; i > 0; i--) {
416	greg	1.17	if (zfd != -1 && write(zfd, (char *)zbar[i],
417	greg	2.8	hres*sizeof(float))
418			< hres*sizeof(float))
419	greg	1.1	goto writerr;
420	greg	2.8	if (fwritescan(scanbar[i], hres, stdout) < 0)
421	greg	1.11	goto writerr;
422			}
423	greg	1.1	if (fflush(stdout) == EOF)
424			goto writerr;
425	greg	1.24	/* record progress */
426	greg	2.8	pctdone = 100.0*(vres-1-ypos)/vres;
427	greg	2.31	if (ralrm > 0 && time((unsigned long *)NULL) >= tlastrept+ralrm)
428	greg	1.24	report();
429	greg	2.14	#ifndef BSD
430	greg	1.32	else
431	greg	2.22	signal(SIGCONT, report);
432	greg	1.32	#endif
433	greg	1.1	}
434	greg	1.11	/* clean up */
435	greg	2.22	signal(SIGCONT, SIG_IGN);
436	greg	1.16	if (zfd != -1) {
437	greg	2.8	if (write(zfd, (char )zbar[0], hressizeof(float))
438			< hres*sizeof(float))
439	greg	1.11	goto writerr;
440	greg	1.20	if (close(zfd) == -1)
441			goto writerr;
442	greg	1.11	for (i = 0; i <= psample; i++)
443			free((char *)zbar[i]);
444			}
445	greg	2.8	fwritescan(scanbar[0], hres, stdout);
446	greg	1.10	if (fflush(stdout) == EOF)
447			goto writerr;
448	greg	1.1	for (i = 0; i <= psample; i++)
449			free((char *)scanbar[i]);
450	greg	2.2	if (sampdens != NULL)
451			free(sampdens);
452	greg	1.11	pctdone = 100.0;
453	greg	2.13	if (ralrm > 0)
454			report();
455	greg	2.23	signal(SIGCONT, SIG_DFL);
456	greg	1.1	return;
457			writerr:
458			error(SYSTEM, "write error in render");
459	greg	1.11	memerr:
460			error(SYSTEM, "out of memory in render");
461	greg	1.1	}
462
463
464	greg	2.2	fillscanline(scanline, zline, sd, xres, y, xstep) /* fill scan at y */
465	greg	2.14	register COLOR *scanline;
466			register float *zline;
467	greg	2.2	register char *sd;
468	greg	1.9	int xres, y, xstep;
469	greg	1.1	{
470	greg	1.33	static int nc = 0; /* number of calls */
471	greg	2.2	int bl = xstep, b = xstep;
472	greg	2.14	double z;
473	greg	1.1	register int i;
474
475	greg	1.11	z = pixvalue(scanline[0], 0, y);
476			if (zline) zline[0] = z;
477	greg	1.33	/* zig-zag start for quincunx pattern */
478	greg	2.2	for (i = ++nc & 1 ? xstep : xstep/2; i < xres-1+xstep; i += xstep) {
479	greg	1.15	if (i >= xres) {
480			xstep += xres-1-i;
481			i = xres-1;
482			}
483	greg	1.11	z = pixvalue(scanline[i], i, y);
484			if (zline) zline[i] = z;
485	greg	2.2	if (sd) b = sd[0] > sd[1] ? sd[0] : sd[1];
486	greg	2.3	if (i <= xstep)
487			b = fillsample(scanline, zline, 0, y, i, 0, b/2);
488			else
489			b = fillsample(scanline+i-xstep,
490			zline ? zline+i-xstep : NULL,
491			i-xstep, y, xstep, 0, b/2);
492	greg	2.2	if (sd) *sd++ = nc & 1 ? bl : b;
493			bl = b;
494	greg	1.1	}
495	greg	2.2	if (sd && nc & 1) *sd = bl;
496	greg	1.1	}
497
498
499	greg	1.11	fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */
500	greg	2.14	register COLOR *scanbar[];
501			register float *zbar[];
502	greg	1.9	int xres, y, ysize;
503	greg	1.1	{
504			COLOR vline[MAXDIV+1];
505	greg	1.11	float zline[MAXDIV+1];
506	greg	1.1	int b = ysize;
507			register int i, j;
508
509	greg	1.8	for (i = 0; i < xres; i++) {
510	greg	1.1
511			copycolor(vline[0], scanbar[0][i]);
512			copycolor(vline[ysize], scanbar[ysize][i]);
513	greg	1.11	if (zbar[0]) {
514			zline[0] = zbar[0][i];
515			zline[ysize] = zbar[ysize][i];
516			}
517	greg	1.1
518	greg	1.11	b = fillsample(vline, zbar[0] ? zline : NULL,
519			i, y, 0, ysize, b/2);
520	greg	1.1
521			for (j = 1; j < ysize; j++)
522			copycolor(scanbar[j][i], vline[j]);
523	greg	1.11	if (zbar[0])
524			for (j = 1; j < ysize; j++)
525			zbar[j][i] = zline[j];
526	greg	1.1	}
527			}
528
529
530			int
531	greg	2.14	fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */
532			register COLOR *colline;
533			register float *zline;
534	greg	1.1	int x, y;
535			int xlen, ylen;
536			int b;
537			{
538	greg	2.14	double ratio;
539			double z;
540	greg	1.1	COLOR ctmp;
541			int ncut;
542			register int len;
543
544			if (xlen > 0) /* x or y length is zero */
545			len = xlen;
546			else
547			len = ylen;
548
549			if (len <= 1) /* limit recursion */
550			return(0);
551
552	greg	1.11	if (b > 0
553			\|\| (zline && 2.fabs(zline[0]-zline[len]) > maxdiff(zline[0]+zline[len]))
554			\|\| bigdiff(colline[0], colline[len], maxdiff)) {
555	greg	1.1
556	greg	1.11	z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
557			if (zline) zline[len>>1] = z;
558	greg	1.1	ncut = 1;
559
560			} else { /* interpolate */
561
562			copycolor(colline[len>>1], colline[len]);
563			ratio = (double)(len>>1) / len;
564			scalecolor(colline[len>>1], ratio);
565	greg	1.11	if (zline) zline[len>>1] = zline[len] * ratio;
566			ratio = 1.0 - ratio;
567	greg	1.1	copycolor(ctmp, colline[0]);
568			scalecolor(ctmp, ratio);
569			addcolor(colline[len>>1], ctmp);
570	greg	1.11	if (zline) zline[len>>1] += zline[0] * ratio;
571	greg	1.1	ncut = 0;
572			}
573			/* recurse */
574	greg	1.11	ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);
575	greg	1.1
576	greg	1.11	ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : NULL,
577			x+(xlen>>1), y+(ylen>>1),
578			xlen-(xlen>>1), ylen-(ylen>>1), b/2);
579	greg	1.1
580			return(ncut);
581			}
582
583
584	greg	1.11	double
585	greg	1.1	pixvalue(col, x, y) /* compute pixel value */
586			COLOR col; /* returned color */
587			int x, y; /* pixel position */
588			{
589	greg	1.25	static RAY thisray;
590	greg	1.1
591	greg	1.22	if (viewray(thisray.rorg, thisray.rdir, &ourview,
592	greg	2.8	(x+pixjitter())/hres, (y+pixjitter())/vres) < 0) {
593	greg	1.22	setcolor(col, 0.0, 0.0, 0.0);
594			return(0.0);
595			}
596	greg	1.1
597			rayorigin(&thisray, NULL, PRIMARY, 1.0);
598	greg	1.25
599	greg	2.8	samplendx = pixnumber(x,y,hres,vres); /* set pixel index */
600	greg	1.25
601	greg	1.1	rayvalue(&thisray); /* trace ray */
602
603			copycolor(col, thisray.rcol); /* return color */
604	greg	1.11
605	greg	1.20	return(thisray.rt); /* return distance */
606	greg	1.1	}
607
608
609			int
610			salvage(oldfile) /* salvage scanlines from killed program */
611			char *oldfile;
612			{
613			COLR *scanline;
614			FILE *fp;
615			int x, y;
616
617			if (oldfile == NULL)
618			return(0);
619	greg	1.9
620			if ((fp = fopen(oldfile, "r")) == NULL) {
621	greg	1.1	sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
622			error(WARNING, errmsg);
623			return(0);
624			}
625	greg	2.17	#ifdef MSDOS
626			setmode(fileno(fp), O_BINARY);
627			#endif
628	greg	1.1	/* discard header */
629	greg	2.19	getheader(fp, NULL, NULL);
630	greg	1.1	/* get picture size */
631	greg	1.36	if (!fscnresolu(&x, &y, fp)) {
632	greg	2.29	sprintf(errmsg, "bad recover file \"%s\" - not removed",
633			oldfile);
634	greg	1.2	error(WARNING, errmsg);
635	greg	1.1	fclose(fp);
636			return(0);
637			}
638
639	greg	2.8	if (x != hres \|\| y != vres) {
640	greg	1.1	sprintf(errmsg, "resolution mismatch in recover file \"%s\"",
641			oldfile);
642			error(USER, errmsg);
643			}
644
645	greg	2.8	scanline = (COLR )malloc(hressizeof(COLR));
646	greg	1.1	if (scanline == NULL)
647			error(SYSTEM, "out of memory in salvage");
648	greg	2.8	for (y = 0; y < vres; y++) {
649			if (freadcolrs(scanline, hres, fp) < 0)
650	greg	1.1	break;
651	greg	2.8	if (fwritecolrs(scanline, hres, stdout) < 0)
652	greg	1.1	goto writerr;
653			}
654			if (fflush(stdout) == EOF)
655			goto writerr;
656			free((char *)scanline);
657			fclose(fp);
658			unlink(oldfile);
659			return(y);
660			writerr:
661	greg	2.9	sprintf(errmsg, "write error during recovery of \"%s\"", oldfile);
662			error(SYSTEM, errmsg);
663	greg	1.31	}
664
665
666			int
667			pixnumber(x, y, xres, yres) /* compute pixel index (brushed) */
668			register int x, y;
669			int xres, yres;
670			{
671			x -= y;
672			while (x < 0)
673			x += xres;
674			return((((x>>2)*yres + y) << 2) + (x & 3));
675	greg	1.1	}