src/px/pinterp.c

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

/*
 * Interpolate and extrapolate pictures with different view parameters.
 *
 *      Greg Ward       09Dec89
 */

#include "standard.h"

#include <sys/fcntl.h>

#include "view.h"

#include "color.h"

#define pscan(y)        (ourpict+(y)*hresolu)
#define zscan(y)        (ourzbuf+(y)*hresolu)

#define F_FORE          1               /* fill foreground */
#define F_BACK          2               /* fill background */

#define PACKSIZ         42              /* calculation packet size */

#define RTCOM           "rtrace -h -ovl -fff -x %d %s"

#define ABS(x)          ((x)>0?(x):-(x))

struct position {int x,y; float z;};

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

double  zeps = .02;                     /* allowed z epsilon */

COLR    *ourpict;                       /* output picture */
float   *ourzbuf;                       /* corresponding z-buffer */

char    *progname;

int     fill = F_FORE|F_BACK;           /* selected fill algorithm */
extern int      backfill(), rcalfill(); /* fill functions */
int     (*deffill)() = backfill;        /* selected fill function */
COLR    backcolr = BLKCOLR;             /* background color */
double  backz = 0.0;                    /* background z value */
int     normdist = 1;                   /* normalized distance? */
double  ourexp = -1;                    /* output picture exposure */

VIEW    theirview = STDVIEW;            /* input view */
int     gotview;                        /* got input view? */
int     thresolu, tvresolu;             /* input resolution */
double  theirexp;                       /* input picture exposure */
double  theirs2ours[4][4];              /* transformation matrix */

int     childpid = -1;                  /* id of fill process */
FILE    *psend, *precv;                 /* pipes to/from fill calculation */
int     queue[PACKSIZ][2];              /* pending pixels */
int     queuesiz;                       /* number of pixels pending */


main(argc, argv)                        /* interpolate pictures */
int     argc;
char    *argv[];
{
#define check(olen,narg)        if (argv[i][olen] || narg >= argc-i) goto badopt
        extern double   atof();
        int     gotvfile = 0;
        char    *zfile = NULL;
        char    *err;
        int     i, rval;

        progname = argv[0];

        for (i = 1; i < argc && argv[i][0] == '-'; i++) {
                rval = getviewopt(&ourview, argc-i, argv+i);
                if (rval >= 0) {
                        i += rval;
                        continue;
                }
                switch (argv[i][1]) {
                case 't':                               /* threshold */
                        check(2,1);
                        zeps = atof(argv[++i]);
                        break;
                case 'n':                               /* dist. normalized? */
                        check(2,0);
                        normdist = !normdist;
                        break;
                case 'f':                               /* fill type */
                        switch (argv[i][2]) {
                        case '0':                               /* none */
                                check(3,0);
                                fill = 0;
                                break;
                        case 'f':                               /* foreground */
                                check(3,0);
                                fill = F_FORE;
                                break;
                        case 'b':                               /* background */
                                check(3,0);
                                fill = F_BACK;
                                break;
                        case 'a':                               /* all */
                                check(3,0);
                                fill = F_FORE|F_BACK;
                                break;
                        case 'c':                               /* color */
                                check(3,3);
                                deffill = backfill;
                                setcolr(backcolr, atof(argv[i+1]),
                                        atof(argv[i+2]), atof(argv[i+3]));
                                i += 3;
                                break;
                        case 'z':                               /* z value */
                                check(3,1);
                                deffill = backfill;
                                backz = atof(argv[++i]);
                                break;
                        case 'r':                               /* rtrace */
                                check(3,1);
                                deffill = rcalfill;
                                calstart(RTCOM, argv[++i]);
                                break;
                        default:
                                goto badopt;
                        }
                        break;
                case 'z':                               /* z file */
                        check(2,1);
                        zfile = argv[++i];
                        break;
                case 'x':                               /* x resolution */
                        check(2,1);
                        hresolu = atoi(argv[++i]);
                        break;
                case 'y':                               /* y resolution */
                        check(2,1);
                        vresolu = atoi(argv[++i]);
                        break;
                case 'p':                               /* pixel aspect */
                        check(2,1);
                        pixaspect = atof(argv[++i]);
                        break;
                case 'v':                               /* view file */
                        if (argv[i][2] != 'f')
                                goto badopt;
                        check(3,1);
                        gotvfile = viewfile(argv[++i], &ourview, 0, 0);
                        if (gotvfile < 0) {
                                perror(argv[i]);
                                exit(1);
                        } else if (gotvfile == 0) {
                                fprintf(stderr, "%s: bad view file\n",
                                                argv[i]);
                                exit(1);
                        }
                        break;
                default:
                badopt:
                        fprintf(stderr, "%s: command line error at '%s'\n",
                                        progname, argv[i]);
                        goto userr;
                }
        }
                                                /* check arguments */
        if ((argc-i)%2)
                goto userr;
                                                /* set view */
        if (err = setview(&ourview)) {
                fprintf(stderr, "%s: %s\n", progname, err);
                exit(1);
        }
        normaspect(viewaspect(&ourview), &pixaspect, &hresolu, &vresolu);
                                                /* allocate frame */
        ourpict = (COLR *)malloc(hresolu*vresolu*sizeof(COLR));
        ourzbuf = (float *)calloc(hresolu*vresolu,sizeof(float));
        if (ourpict == NULL || ourzbuf == NULL)
                syserror();
                                                        /* get input */
        for ( ; i < argc; i += 2)
                addpicture(argv[i], argv[i+1]);
                                                        /* fill in spaces */
        if (fill&F_BACK)
                backpicture();
        else
                fillpicture();
                                                        /* close calculation */
        caldone();
                                                        /* add to header */
        printargs(argc, argv, stdout);
        if (gotvfile) {
                printf(VIEWSTR);
                fprintview(&ourview, stdout);
                printf("\n");
        }
        if (pixaspect < .99 || pixaspect > 1.01)
                fputaspect(pixaspect, stdout);
        if (ourexp > 0 && (ourexp < .995 || ourexp > 1.005))
                fputexpos(ourexp, stdout);
        printf("\n");
                                                        /* write picture */
        writepicture();
                                                        /* write z file */
        if (zfile != NULL)
                writedistance(zfile);

        exit(0);
userr:
        fprintf(stderr,
        "Usage: %s [view opts][-t eps][-z zout][-fT][-n] pfile zspec ..\n",
                        progname);
        exit(1);
#undef check
}


headline(s)                             /* process header string */
char    *s;
{
        static char     *altname[] = {"rview","rpict","pinterp",VIEWSTR,NULL};
        register char   **an;

        printf("\t%s", s);

        if (isexpos(s)) {
                theirexp *= exposval(s);
                return;
        }
        for (an = altname; *an != NULL; an++)
                if (!strncmp(*an, s, strlen(*an))) {
                        if (sscanview(&theirview, s+strlen(*an)) > 0)
                                gotview++;
                        break;
                }
}


addpicture(pfile, zspec)                /* add picture to output */
char    *pfile, *zspec;
{
        extern double   atof();
        FILE    *pfp;
        int     zfd;
        char    *err;
        COLR    *scanin;
        float   *zin;
        struct position *plast;
        int     y;
                                        /* open picture file */
        if ((pfp = fopen(pfile, "r")) == NULL) {
                perror(pfile);
                exit(1);
        }
                                        /* get header with exposure and view */
        theirexp = 1.0;
        gotview = 0;
        printf("%s:\n", pfile);
        getheader(pfp, headline);
        if (!gotview || fgetresolu(&thresolu, &tvresolu, pfp)
                        != (YMAJOR|YDECR)) {
                fprintf(stderr, "%s: picture view error\n", pfile);
                exit(1);
        }
        if (ourexp <= 0)
                ourexp = theirexp;
        else if (ABS(theirexp-ourexp) > .01*ourexp)
                fprintf(stderr, "%s: different exposure (warning)\n", pfile);
        if (err = setview(&theirview)) {
                fprintf(stderr, "%s: %s\n", pfile, err);
                exit(1);
        }
                                        /* compute transformation */
        pixform(theirs2ours, &theirview, &ourview);
                                        /* allocate scanlines */
        scanin = (COLR *)malloc(thresolu*sizeof(COLR));
        zin = (float *)malloc(thresolu*sizeof(float));
        plast = (struct position *)calloc(thresolu, sizeof(struct position));
        if (scanin == NULL || zin == NULL || plast == NULL)
                syserror();
                                        /* get z specification or file */
        if ((zfd = open(zspec, O_RDONLY)) == -1) {
                double  zvalue;
                register int    x;
                if (!isfloat(zspec) || (zvalue = atof(zspec)) <= 0.0) {
                        perror(zspec);
                        exit(1);
                }
                for (x = 0; x < thresolu; x++)
                        zin[x] = zvalue;
        }
                                        /* load image */
        for (y = tvresolu-1; y >= 0; y--) {
                if (freadcolrs(scanin, thresolu, pfp) < 0) {
                        fprintf(stderr, "%s: read error\n", pfile);
                        exit(1);
                }
                if (zfd != -1 && read(zfd,zin,thresolu*sizeof(float))
                                < thresolu*sizeof(float)) {
                        fprintf(stderr, "%s: read error\n", zspec);
                        exit(1);
                }
                addscanline(y, scanin, zin, plast);
        }
                                        /* clean up */
        free((char *)scanin);
        free((char *)zin);
        free((char *)plast);
        fclose(pfp);
        if (zfd != -1)
                close(zfd);
}


pixform(xfmat, vw1, vw2)                /* compute view1 to view2 matrix */
register double xfmat[4][4];
register VIEW   *vw1, *vw2;
{
        double  m4t[4][4];

        setident4(xfmat);
        xfmat[0][0] = vw1->hvec[0];
        xfmat[0][1] = vw1->hvec[1];
        xfmat[0][2] = vw1->hvec[2];
        xfmat[1][0] = vw1->vvec[0];
        xfmat[1][1] = vw1->vvec[1];
        xfmat[1][2] = vw1->vvec[2];
        xfmat[2][0] = vw1->vdir[0];
        xfmat[2][1] = vw1->vdir[1];
        xfmat[2][2] = vw1->vdir[2];
        xfmat[3][0] = vw1->vp[0];
        xfmat[3][1] = vw1->vp[1];
        xfmat[3][2] = vw1->vp[2];
        setident4(m4t);
        m4t[0][0] = vw2->hvec[0]/vw2->hn2;
        m4t[1][0] = vw2->hvec[1]/vw2->hn2;
        m4t[2][0] = vw2->hvec[2]/vw2->hn2;
        m4t[3][0] = -DOT(vw2->vp,vw2->hvec)/vw2->hn2;
        m4t[0][1] = vw2->vvec[0]/vw2->vn2;
        m4t[1][1] = vw2->vvec[1]/vw2->vn2;
        m4t[2][1] = vw2->vvec[2]/vw2->vn2;
        m4t[3][1] = -DOT(vw2->vp,vw2->vvec)/vw2->vn2;
        m4t[0][2] = vw2->vdir[0];
        m4t[1][2] = vw2->vdir[1];
        m4t[2][2] = vw2->vdir[2];
        m4t[3][2] = -DOT(vw2->vp,vw2->vdir);
        multmat4(xfmat, xfmat, m4t);
}


addscanline(y, pline, zline, lasty)     /* add scanline to output */
int     y;
COLR    *pline;
float   *zline;
struct position *lasty;         /* input/output */
{
        extern double   sqrt();
        double  pos[3];
        struct position lastx, newpos;
        register int    x;

        for (x = thresolu-1; x >= 0; x--) {
                pos[0] = (x+.5)/thresolu + theirview.hoff - .5;
                pos[1] = (y+.5)/tvresolu + theirview.voff - .5;
                pos[2] = zline[x];
                if (theirview.type == VT_PER) {
                        if (normdist)   /* adjust for eye-ray distance */
                                pos[2] /= sqrt( 1.
                                        + pos[0]*pos[0]*theirview.hn2
                                        + pos[1]*pos[1]*theirview.vn2 );
                        pos[0] *= pos[2];
                        pos[1] *= pos[2];
                }
                multp3(pos, pos, theirs2ours);
                if (pos[2] <= 0) {
                        lasty[x].z = lastx.z = 0;       /* mark invalid */
                        continue;
                }
                if (ourview.type == VT_PER) {
                        pos[0] /= pos[2];
                        pos[1] /= pos[2];
                }
                pos[0] += .5 - ourview.hoff;
                pos[1] += .5 - ourview.voff;
                newpos.x = pos[0] * hresolu;
                newpos.y = pos[1] * vresolu;
                newpos.z = zline[x];
                                        /* add pixel to our image */
                if (pos[0] >= 0 && newpos.x < hresolu
                                && pos[1] >= 0 && newpos.y < vresolu) {
                        addpixel(&newpos, &lastx, &lasty[x], pline[x], pos[2]);
                        lasty[x].x = lastx.x = newpos.x;
                        lasty[x].y = lastx.y = newpos.y;
                        lasty[x].z = lastx.z = newpos.z;
                } else
                        lasty[x].z = lastx.z = 0;       /* mark invalid */
        }
}


addpixel(p0, p1, p2, pix, z)            /* fill in pixel parallelogram */
struct position *p0, *p1, *p2;
COLR    pix;
double  z;
{
        double  zt = 2.*zeps*p0->z;             /* threshold */
        int     s1x, s1y, s2x, s2y;             /* step sizes */
        int     l1, l2, c1, c2;                 /* side lengths and counters */
        int     p1isy;                          /* p0p1 along y? */
        int     x1, y1;                         /* p1 position */
        register int    x, y;                   /* final position */

                                        /* compute vector p0p1 */
        if (fill&F_FORE && ABS(p1->z-p0->z) <= zt) {
                s1x = p1->x - p0->x;
                s1y = p1->y - p0->y;
                l1 = ABS(s1x);
                if (p1isy = (ABS(s1y) > l1))
                        l1 = ABS(s1y);
        } else {
                l1 = s1x = s1y = 1;
                p1isy = -1;
        }
                                        /* compute vector p0p2 */
        if (fill&F_FORE && ABS(p2->z-p0->z) <= zt) {
                s2x = p2->x - p0->x;
                s2y = p2->y - p0->y;
                if (p1isy == 1)
                        l2 = ABS(s2x);
                else {
                        l2 = ABS(s2y);
                        if (p1isy != 0 && ABS(s2x) > l2)
                                l2 = ABS(s2x);
                }
        } else
                l2 = s2x = s2y = 1;
                                        /* fill the parallelogram */
        for (c1 = l1; c1-- > 0; ) {
                x1 = p0->x + c1*s1x/l1;
                y1 = p0->y + c1*s1y/l1;
                for (c2 = l2; c2-- > 0; ) {
                        x = x1 + c2*s2x/l2;
                        y = y1 + c2*s2y/l2;
                        if (zscan(y)[x] <= 0 || zscan(y)[x]-z
                                                > zeps*zscan(y)[x]) {
                                zscan(y)[x] = z;
                                copycolr(pscan(y)[x], pix);
                        }
                }
        }
}


backpicture()                           /* background fill algorithm */
{
        int     *yback, xback;
        int     y;
        COLR    pfill;
        register int    x, i;
                                                        /* get back buffer */
        yback = (int *)malloc(hresolu*sizeof(int));
        if (yback == NULL)
                syserror();
        for (x = 0; x < hresolu; x++)
                yback[x] = -2;
        /*
         * Xback and yback are the pixel locations of suitable
         * background values in each direction.
         * A value of -2 means unassigned, and -1 means
         * that there is no suitable background in this direction.
         */
                                                        /* fill image */
        for (y = 0; y < vresolu; y++) {
                xback = -2;
                for (x = 0; x < hresolu; x++)
                        if (zscan(y)[x] <= 0) {         /* empty pixel */
                                /*
                                 * First, find background from above or below.
                                 * (farthest assigned pixel)
                                 */
                                if (yback[x] == -2) {
                                        for (i = y+1; i < vresolu; i++)
                                                if (zscan(i)[x] > 0)
                                                        break;
                                        if (i < vresolu
                                && (y <= 0 || zscan(y-1)[x] < zscan(i)[x]))
                                                yback[x] = i;
                                        else
                                                yback[x] = y-1;
                                }
                                /*
                                 * Next, find background from left or right.
                                 */
                                if (xback == -2) {
                                        for (i = x+1; i < hresolu; i++)
                                                if (zscan(y)[i] > 0)
                                                        break;
                                        if (i < hresolu
                                && (x <= 0 || zscan(y)[x-1] < zscan(y)[i]))
                                                xback = i;
                                        else
                                                xback = x-1;
                                }
                                /*
                                 * Check to see if we have no background for
                                 * this pixel.  If not, use background color.
                                 */
                                if (xback < 0 && yback[x] < 0) {
                                        (*deffill)(x,y);
                                        continue;
                                }
                                /*
                                 * Compare, and use the background that is
                                 * farther, unless one of them is next to us.
                                 */
                                if ( yback[x] < 0
                                        || (xback >= 0 && ABS(x-xback) <= 1)
                                        || ( ABS(y-yback[x]) > 1
                                                && zscan(yback[x])[x]
                                                < zscan(y)[xback] ) ) {
                                        copycolr(pscan(y)[x],pscan(y)[xback]);
                                        zscan(y)[x] = zscan(y)[xback];
                                } else {
                                        copycolr(pscan(y)[x],pscan(yback[x])[x]);
                                        zscan(y)[x] = zscan(yback[x])[x];
                                }
                        } else {                                /* full pixel */
                                yback[x] = -2;
                                xback = -2;
                        }
        }
        free((char *)yback);
}


fillpicture()                           /* paint in empty pixels with default */
{
        register int    x, y;

        for (y = 0; y < vresolu; y++)
                for (x = 0; x < hresolu; x++)
                        if (zscan(y)[x] <= 0)
                                (*deffill)(x,y);
}


writepicture()                          /* write out picture */
{
        int     y;

        fputresolu(YMAJOR|YDECR, hresolu, vresolu, stdout);
        for (y = vresolu-1; y >= 0; y--)
                if (fwritecolrs(pscan(y), hresolu, stdout) < 0)
                        syserror();
}


writedistance(fname)                    /* write out z file */
char    *fname;
{
        extern double   sqrt();
        int     donorm = normdist && ourview.type == VT_PER;
        int     fd;
        int     y;
        float   *zout;

        if ((fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) == -1) {
                perror(fname);
                exit(1);
        }
        if (donorm
        && (zout = (float *)malloc(hresolu*sizeof(float))) == NULL)
                syserror();
        for (y = vresolu-1; y >= 0; y--) {
                if (donorm) {
                        double  vx, yzn2;
                        register int    x;
                        yzn2 = y - .5*(vresolu-1);
                        yzn2 = 1. + yzn2*yzn2*ourview.vn2;
                        for (x = 0; x < hresolu; x++) {
                                vx = x - .5*(hresolu-1);
                                zout[x] = zscan(y)[x]
                                        * sqrt(vx*vx*ourview.hn2 + yzn2);
                        }
                } else
                        zout = zscan(y);
                if (write(fd, zout, hresolu*sizeof(float))
                                < hresolu*sizeof(float)) {
                        perror(fname);
                        exit(1);
                }
        }
        if (donorm)
                free((char *)zout);
        close(fd);
}


isfloat(s)                              /* see if string is floating number */
register char   *s;
{
        for ( ; *s; s++)
                if ((*s < '0' || *s > '9') && *s != '.' && *s != '-'
                                && *s != 'e' && *s != 'E' && *s != '+')
                        return(0);
        return(1);
}


backfill(x, y)                          /* fill pixel with background */
int     x, y;
{
        register BYTE   *dest = pscan(y)[x];

        copycolr(dest, backcolr);
        zscan(y)[x] = backz;
}


calstart(prog, args)                    /* start fill calculation */
char    *prog, *args;
{
        char    combuf[512];
        int     p0[2], p1[2];

        if (childpid != -1) {
                fprintf(stderr, "%s: too many calculations\n", progname);
                exit(1);
        }
        sprintf(combuf, prog, PACKSIZ, args);
        if (pipe(p0) < 0 || pipe(p1) < 0)
                syserror();
        if ((childpid = vfork()) == 0) {        /* fork calculation */
                close(p0[1]);
                close(p1[0]);
                if (p0[0] != 0) {
                        dup2(p0[0], 0);
                        close(p0[0]);
                }
                if (p1[1] != 1) {
                        dup2(p1[1], 1);
                        close(p1[1]);
                }
                execl("/bin/sh", "sh", "-c", combuf, 0);
                perror("/bin/sh");
                _exit(127);
        }
        if (childpid == -1)
                syserror();
        close(p0[0]);
        close(p1[1]);
        if ((psend = fdopen(p0[1], "w")) == NULL)
                syserror();
        if ((precv = fdopen(p1[0], "r")) == NULL)
                syserror();
        queuesiz = 0;
}


caldone()                               /* done with calculation */
{
        int     pid;

        if (childpid == -1)
                return;
        if (fclose(psend) == EOF)
                syserror();
        clearqueue();
        fclose(precv);
        while ((pid = wait(0)) != -1 && pid != childpid)
                ;
        childpid = -1;
}


rcalfill(x, y)                          /* fill with ray-calculated pixel */
int     x, y;
{
        FVECT   orig, dir;
        float   outbuf[6];

        if (queuesiz >= PACKSIZ) {      /* flush queue */
                if (fflush(psend) == EOF)
                        syserror();
                clearqueue();
        }
                                        /* send new ray */
        viewray(orig, dir, &ourview, (x+.5)/hresolu, (y+.5)/vresolu);
        outbuf[0] = orig[0]; outbuf[1] = orig[1]; outbuf[2] = orig[2];
        outbuf[3] = dir[0]; outbuf[4] = dir[1]; outbuf[5] = dir[2];
        if (fwrite(outbuf, sizeof(float), 6, psend) < 6)
                syserror();
                                        /* remember it */
        queue[queuesiz][0] = x;
        queue[queuesiz][1] = y;
        queuesiz++;
}


clearqueue()                            /* get results from queue */
{
        float   inbuf[4];
        register int    i;

        for (i = 0; i < queuesiz; i++) {
                if (fread(inbuf, sizeof(float), 4, precv) < 4) {
                        fprintf(stderr, "%s: read error in clearqueue\n",
                                        progname);
                        exit(1);
                }
                if (ourexp > 0 && ourexp != 1.0) {
                        inbuf[0] *= ourexp;
                        inbuf[1] *= ourexp;
                        inbuf[2] *= ourexp;
                }
                setcolr(pscan(queue[i][1])[queue[i][0]],
                                inbuf[0], inbuf[1], inbuf[2]);
                zscan(queue[i][1])[queue[i][0]] = inbuf[3];
        }
        queuesiz = 0;
}


syserror()                      /* report error and exit */
{
        perror(progname);
        exit(1);
}
Revision:	1.19
Committed:	Tue Jan 16 11:29:14 1990 UTC (34 years, 3 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.18:	+15 -11 lines
Log Message:	changed reading and writing of z-files and viewfiles
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2			static char SCCSid[] = "$SunId$ LBL";
3			#endif
4
5			/*
6			* Interpolate and extrapolate pictures with different view parameters.
7			*
8			* Greg Ward 09Dec89
9			*/
10
11			#include "standard.h"
12
13	greg	1.19	#include <sys/fcntl.h>
14
15	greg	1.1	#include "view.h"
16
17			#include "color.h"
18
19	greg	1.17	#define pscan(y) (ourpict+(y)*hresolu)
20			#define zscan(y) (ourzbuf+(y)*hresolu)
21	greg	1.1
22	greg	1.13	#define F_FORE 1 /* fill foreground */
23			#define F_BACK 2 /* fill background */
24	greg	1.11
25	greg	1.13	#define PACKSIZ 42 /* calculation packet size */
26
27			#define RTCOM "rtrace -h -ovl -fff -x %d %s"
28
29	greg	1.3	#define ABS(x) ((x)>0?(x):-(x))
30
31	greg	1.15	struct position {int x,y; float z;};
32
33	greg	1.17	VIEW ourview = STDVIEW; /* desired view */
34			int hresolu = 512; /* horizontal resolution */
35			int vresolu = 512; /* vertical resolution */
36	greg	1.18	double pixaspect = 1.0; /* pixel aspect ratio */
37	greg	1.1
38	greg	1.8	double zeps = .02; /* allowed z epsilon */
39	greg	1.1
40			COLR ourpict; / output picture */
41			float ourzbuf; / corresponding z-buffer */
42
43			char *progname;
44
45	greg	1.12	int fill = F_FORE\|F_BACK; /* selected fill algorithm */
46	greg	1.14	extern int backfill(), rcalfill(); /* fill functions */
47	greg	1.12	int (deffill)() = backfill; / selected fill function */
48	greg	1.11	COLR backcolr = BLKCOLR; /* background color */
49	greg	1.13	double backz = 0.0; /* background z value */
50	greg	1.16	int normdist = 1; /* normalized distance? */
51			double ourexp = -1; /* output picture exposure */
52	greg	1.11
53	greg	1.17	VIEW theirview = STDVIEW; /* input view */
54	greg	1.16	int gotview; /* got input view? */
55	greg	1.17	int thresolu, tvresolu; /* input resolution */
56			double theirexp; /* input picture exposure */
57	greg	1.5	double theirs2ours[4][4]; /* transformation matrix */
58	greg	1.1
59	greg	1.14	int childpid = -1; /* id of fill process */
60	greg	1.13	FILE psend, precv; /* pipes to/from fill calculation */
61			int queue[PACKSIZ][2]; /* pending pixels */
62			int queuesiz; /* number of pixels pending */
63	greg	1.5
64	greg	1.13
65	greg	1.1	main(argc, argv) /* interpolate pictures */
66			int argc;
67			char *argv[];
68			{
69			#define check(olen,narg) if (argv[i][olen] \|\| narg >= argc-i) goto badopt
70	greg	1.11	extern double atof();
71	greg	1.1	int gotvfile = 0;
72	greg	1.11	char *zfile = NULL;
73	greg	1.1	char *err;
74	greg	1.17	int i, rval;
75	greg	1.1
76			progname = argv[0];
77
78	greg	1.17	for (i = 1; i < argc && argv[i][0] == '-'; i++) {
79			rval = getviewopt(&ourview, argc-i, argv+i);
80			if (rval >= 0) {
81			i += rval;
82			continue;
83			}
84	greg	1.1	switch (argv[i][1]) {
85			case 't': /* threshold */
86			check(2,1);
87			zeps = atof(argv[++i]);
88			break;
89	greg	1.11	case 'n': /* dist. normalized? */
90	greg	1.10	check(2,0);
91	greg	1.11	normdist = !normdist;
92	greg	1.10	break;
93	greg	1.11	case 'f': /* fill type */
94			switch (argv[i][2]) {
95			case '0': /* none */
96			check(3,0);
97			fill = 0;
98			break;
99			case 'f': /* foreground */
100			check(3,0);
101			fill = F_FORE;
102			break;
103			case 'b': /* background */
104			check(3,0);
105			fill = F_BACK;
106			break;
107			case 'a': /* all */
108			check(3,0);
109			fill = F_FORE\|F_BACK;
110			break;
111			case 'c': /* color */
112			check(3,3);
113	greg	1.12	deffill = backfill;
114	greg	1.11	setcolr(backcolr, atof(argv[i+1]),
115			atof(argv[i+2]), atof(argv[i+3]));
116			i += 3;
117			break;
118	greg	1.13	case 'z': /* z value */
119			check(3,1);
120			deffill = backfill;
121			backz = atof(argv[++i]);
122			break;
123			case 'r': /* rtrace */
124			check(3,1);
125	greg	1.14	deffill = rcalfill;
126	greg	1.13	calstart(RTCOM, argv[++i]);
127			break;
128	greg	1.11	default:
129			goto badopt;
130			}
131			break;
132			case 'z': /* z file */
133			check(2,1);
134			zfile = argv[++i];
135			break;
136	greg	1.6	case 'x': /* x resolution */
137			check(2,1);
138	greg	1.17	hresolu = atoi(argv[++i]);
139	greg	1.6	break;
140			case 'y': /* y resolution */
141			check(2,1);
142	greg	1.17	vresolu = atoi(argv[++i]);
143	greg	1.6	break;
144	greg	1.18	case 'p': /* pixel aspect */
145			check(2,1);
146			pixaspect = atof(argv[++i]);
147			break;
148	greg	1.17	case 'v': /* view file */
149			if (argv[i][2] != 'f')
150	greg	1.1	goto badopt;
151	greg	1.17	check(3,1);
152	greg	1.19	gotvfile = viewfile(argv[++i], &ourview, 0, 0);
153	greg	1.17	if (gotvfile < 0) {
154			perror(argv[i]);
155			exit(1);
156			} else if (gotvfile == 0) {
157			fprintf(stderr, "%s: bad view file\n",
158			argv[i]);
159			exit(1);
160	greg	1.1	}
161			break;
162			default:
163			badopt:
164	greg	1.10	fprintf(stderr, "%s: command line error at '%s'\n",
165	greg	1.1	progname, argv[i]);
166	greg	1.10	goto userr;
167	greg	1.1	}
168	greg	1.17	}
169	greg	1.1	/* check arguments */
170	greg	1.13	if ((argc-i)%2)
171	greg	1.10	goto userr;
172	greg	1.1	/* set view */
173			if (err = setview(&ourview)) {
174			fprintf(stderr, "%s: %s\n", progname, err);
175			exit(1);
176			}
177	greg	1.18	normaspect(viewaspect(&ourview), &pixaspect, &hresolu, &vresolu);
178	greg	1.1	/* allocate frame */
179	greg	1.17	ourpict = (COLR )malloc(hresoluvresolu*sizeof(COLR));
180			ourzbuf = (float )calloc(hresoluvresolu,sizeof(float));
181	greg	1.15	if (ourpict == NULL \|\| ourzbuf == NULL)
182			syserror();
183	greg	1.1	/* get input */
184			for ( ; i < argc; i += 2)
185			addpicture(argv[i], argv[i+1]);
186			/* fill in spaces */
187	greg	1.11	if (fill&F_BACK)
188	greg	1.12	backpicture();
189			else
190	greg	1.11	fillpicture();
191	greg	1.13	/* close calculation */
192	greg	1.14	caldone();
193	greg	1.1	/* add to header */
194			printargs(argc, argv, stdout);
195			if (gotvfile) {
196			printf(VIEWSTR);
197			fprintview(&ourview, stdout);
198			printf("\n");
199			}
200	greg	1.18	if (pixaspect < .99 \|\| pixaspect > 1.01)
201			fputaspect(pixaspect, stdout);
202			if (ourexp > 0 && (ourexp < .995 \|\| ourexp > 1.005))
203	greg	1.16	fputexpos(ourexp, stdout);
204	greg	1.1	printf("\n");
205	greg	1.11	/* write picture */
206	greg	1.1	writepicture();
207	greg	1.11	/* write z file */
208			if (zfile != NULL)
209			writedistance(zfile);
210	greg	1.1
211			exit(0);
212	greg	1.10	userr:
213			fprintf(stderr,
214	greg	1.17	"Usage: %s [view opts][-t eps][-z zout][-fT][-n] pfile zspec ..\n",
215	greg	1.10	progname);
216			exit(1);
217	greg	1.1	#undef check
218			}
219
220
221			headline(s) /* process header string */
222			char *s;
223			{
224			static char *altname[] = {"rview","rpict","pinterp",VIEWSTR,NULL};
225			register char **an;
226
227			printf("\t%s", s);
228
229	greg	1.16	if (isexpos(s)) {
230			theirexp *= exposval(s);
231			return;
232			}
233	greg	1.1	for (an = altname; *an != NULL; an++)
234			if (!strncmp(an, s, strlen(an))) {
235	greg	1.17	if (sscanview(&theirview, s+strlen(*an)) > 0)
236	greg	1.1	gotview++;
237			break;
238			}
239			}
240
241
242	greg	1.10	addpicture(pfile, zspec) /* add picture to output */
243			char pfile, zspec;
244	greg	1.1	{
245	greg	1.10	extern double atof();
246	greg	1.19	FILE *pfp;
247			int zfd;
248	greg	1.8	char *err;
249	greg	1.1	COLR *scanin;
250	greg	1.15	float *zin;
251			struct position *plast;
252	greg	1.1	int y;
253	greg	1.10	/* open picture file */
254	greg	1.1	if ((pfp = fopen(pfile, "r")) == NULL) {
255			perror(pfile);
256			exit(1);
257			}
258	greg	1.16	/* get header with exposure and view */
259			theirexp = 1.0;
260			gotview = 0;
261	greg	1.1	printf("%s:\n", pfile);
262			getheader(pfp, headline);
263	greg	1.17	if (!gotview \|\| fgetresolu(&thresolu, &tvresolu, pfp)
264	greg	1.9	!= (YMAJOR\|YDECR)) {
265	greg	1.1	fprintf(stderr, "%s: picture view error\n", pfile);
266			exit(1);
267			}
268	greg	1.16	if (ourexp <= 0)
269			ourexp = theirexp;
270			else if (ABS(theirexp-ourexp) > .01*ourexp)
271			fprintf(stderr, "%s: different exposure (warning)\n", pfile);
272	greg	1.1	if (err = setview(&theirview)) {
273			fprintf(stderr, "%s: %s\n", pfile, err);
274			exit(1);
275			}
276	greg	1.5	/* compute transformation */
277			pixform(theirs2ours, &theirview, &ourview);
278	greg	1.1	/* allocate scanlines */
279	greg	1.17	scanin = (COLR )malloc(thresolusizeof(COLR));
280			zin = (float )malloc(thresolusizeof(float));
281			plast = (struct position *)calloc(thresolu, sizeof(struct position));
282	greg	1.15	if (scanin == NULL \|\| zin == NULL \|\| plast == NULL)
283			syserror();
284	greg	1.10	/* get z specification or file */
285	greg	1.19	if ((zfd = open(zspec, O_RDONLY)) == -1) {
286	greg	1.10	double zvalue;
287			register int x;
288			if (!isfloat(zspec) \|\| (zvalue = atof(zspec)) <= 0.0) {
289			perror(zspec);
290			exit(1);
291			}
292	greg	1.17	for (x = 0; x < thresolu; x++)
293	greg	1.10	zin[x] = zvalue;
294			}
295	greg	1.1	/* load image */
296	greg	1.17	for (y = tvresolu-1; y >= 0; y--) {
297			if (freadcolrs(scanin, thresolu, pfp) < 0) {
298	greg	1.1	fprintf(stderr, "%s: read error\n", pfile);
299			exit(1);
300			}
301	greg	1.19	if (zfd != -1 && read(zfd,zin,thresolu*sizeof(float))
302			< thresolu*sizeof(float)) {
303	greg	1.10	fprintf(stderr, "%s: read error\n", zspec);
304	greg	1.1	exit(1);
305			}
306	greg	1.15	addscanline(y, scanin, zin, plast);
307	greg	1.1	}
308			/* clean up */
309			free((char *)scanin);
310			free((char *)zin);
311	greg	1.9	free((char *)plast);
312	greg	1.1	fclose(pfp);
313	greg	1.19	if (zfd != -1)
314			close(zfd);
315	greg	1.1	}
316
317
318	greg	1.5	pixform(xfmat, vw1, vw2) /* compute view1 to view2 matrix */
319			register double xfmat[4][4];
320			register VIEW vw1, vw2;
321			{
322			double m4t[4][4];
323
324			setident4(xfmat);
325	greg	1.17	xfmat[0][0] = vw1->hvec[0];
326			xfmat[0][1] = vw1->hvec[1];
327			xfmat[0][2] = vw1->hvec[2];
328			xfmat[1][0] = vw1->vvec[0];
329			xfmat[1][1] = vw1->vvec[1];
330			xfmat[1][2] = vw1->vvec[2];
331	greg	1.5	xfmat[2][0] = vw1->vdir[0];
332			xfmat[2][1] = vw1->vdir[1];
333			xfmat[2][2] = vw1->vdir[2];
334			xfmat[3][0] = vw1->vp[0];
335			xfmat[3][1] = vw1->vp[1];
336			xfmat[3][2] = vw1->vp[2];
337			setident4(m4t);
338	greg	1.17	m4t[0][0] = vw2->hvec[0]/vw2->hn2;
339			m4t[1][0] = vw2->hvec[1]/vw2->hn2;
340			m4t[2][0] = vw2->hvec[2]/vw2->hn2;
341			m4t[3][0] = -DOT(vw2->vp,vw2->hvec)/vw2->hn2;
342			m4t[0][1] = vw2->vvec[0]/vw2->vn2;
343			m4t[1][1] = vw2->vvec[1]/vw2->vn2;
344			m4t[2][1] = vw2->vvec[2]/vw2->vn2;
345			m4t[3][1] = -DOT(vw2->vp,vw2->vvec)/vw2->vn2;
346	greg	1.5	m4t[0][2] = vw2->vdir[0];
347			m4t[1][2] = vw2->vdir[1];
348			m4t[2][2] = vw2->vdir[2];
349			m4t[3][2] = -DOT(vw2->vp,vw2->vdir);
350			multmat4(xfmat, xfmat, m4t);
351			}
352
353
354	greg	1.15	addscanline(y, pline, zline, lasty) /* add scanline to output */
355	greg	1.1	int y;
356			COLR *pline;
357			float *zline;
358	greg	1.15	struct position lasty; / input/output */
359	greg	1.1	{
360	greg	1.11	extern double sqrt();
361	greg	1.5	double pos[3];
362	greg	1.15	struct position lastx, newpos;
363	greg	1.1	register int x;
364
365	greg	1.17	for (x = thresolu-1; x >= 0; x--) {
366			pos[0] = (x+.5)/thresolu + theirview.hoff - .5;
367			pos[1] = (y+.5)/tvresolu + theirview.voff - .5;
368	greg	1.5	pos[2] = zline[x];
369			if (theirview.type == VT_PER) {
370	greg	1.11	if (normdist) /* adjust for eye-ray distance */
371	greg	1.10	pos[2] /= sqrt( 1.
372	greg	1.17	+ pos[0]pos[0]theirview.hn2
373			+ pos[1]pos[1]theirview.vn2 );
374	greg	1.5	pos[0] *= pos[2];
375			pos[1] *= pos[2];
376			}
377			multp3(pos, pos, theirs2ours);
378	greg	1.15	if (pos[2] <= 0) {
379			lasty[x].z = lastx.z = 0; /* mark invalid */
380	greg	1.1	continue;
381	greg	1.15	}
382	greg	1.5	if (ourview.type == VT_PER) {
383			pos[0] /= pos[2];
384			pos[1] /= pos[2];
385			}
386	greg	1.17	pos[0] += .5 - ourview.hoff;
387			pos[1] += .5 - ourview.voff;
388			newpos.x = pos[0] * hresolu;
389			newpos.y = pos[1] * vresolu;
390	greg	1.15	newpos.z = zline[x];
391	greg	1.8	/* add pixel to our image */
392	greg	1.17	if (pos[0] >= 0 && newpos.x < hresolu
393			&& pos[1] >= 0 && newpos.y < vresolu) {
394	greg	1.15	addpixel(&newpos, &lastx, &lasty[x], pline[x], pos[2]);
395			lasty[x].x = lastx.x = newpos.x;
396			lasty[x].y = lastx.y = newpos.y;
397			lasty[x].z = lastx.z = newpos.z;
398			} else
399			lasty[x].z = lastx.z = 0; /* mark invalid */
400	greg	1.1	}
401			}
402
403
404	greg	1.15	addpixel(p0, p1, p2, pix, z) /* fill in pixel parallelogram */
405			struct position p0, p1, *p2;
406	greg	1.8	COLR pix;
407			double z;
408			{
409	greg	1.15	double zt = 2.zepsp0->z; /* threshold */
410			int s1x, s1y, s2x, s2y; /* step sizes */
411			int l1, l2, c1, c2; /* side lengths and counters */
412			int p1isy; /* p0p1 along y? */
413			int x1, y1; /* p1 position */
414			register int x, y; /* final position */
415
416			/* compute vector p0p1 */
417			if (fill&F_FORE && ABS(p1->z-p0->z) <= zt) {
418			s1x = p1->x - p0->x;
419			s1y = p1->y - p0->y;
420			l1 = ABS(s1x);
421			if (p1isy = (ABS(s1y) > l1))
422			l1 = ABS(s1y);
423			} else {
424			l1 = s1x = s1y = 1;
425			p1isy = -1;
426			}
427			/* compute vector p0p2 */
428			if (fill&F_FORE && ABS(p2->z-p0->z) <= zt) {
429			s2x = p2->x - p0->x;
430			s2y = p2->y - p0->y;
431			if (p1isy == 1)
432			l2 = ABS(s2x);
433			else {
434			l2 = ABS(s2y);
435			if (p1isy != 0 && ABS(s2x) > l2)
436			l2 = ABS(s2x);
437			}
438			} else
439			l2 = s2x = s2y = 1;
440			/* fill the parallelogram */
441			for (c1 = l1; c1-- > 0; ) {
442			x1 = p0->x + c1*s1x/l1;
443			y1 = p0->y + c1*s1y/l1;
444			for (c2 = l2; c2-- > 0; ) {
445			x = x1 + c2*s2x/l2;
446			y = y1 + c2*s2y/l2;
447			if (zscan(y)[x] <= 0 \|\| zscan(y)[x]-z
448			> zeps*zscan(y)[x]) {
449	greg	1.8	zscan(y)[x] = z;
450			copycolr(pscan(y)[x], pix);
451			}
452	greg	1.15	}
453			}
454	greg	1.8	}
455
456
457	greg	1.12	backpicture() /* background fill algorithm */
458	greg	1.1	{
459	greg	1.2	int *yback, xback;
460	greg	1.1	int y;
461	greg	1.2	COLR pfill;
462			register int x, i;
463			/* get back buffer */
464	greg	1.17	yback = (int )malloc(hresolusizeof(int));
465	greg	1.15	if (yback == NULL)
466			syserror();
467	greg	1.17	for (x = 0; x < hresolu; x++)
468	greg	1.4	yback[x] = -2;
469	greg	1.7	/*
470			* Xback and yback are the pixel locations of suitable
471			* background values in each direction.
472			* A value of -2 means unassigned, and -1 means
473			* that there is no suitable background in this direction.
474			*/
475	greg	1.2	/* fill image */
476	greg	1.17	for (y = 0; y < vresolu; y++) {
477	greg	1.4	xback = -2;
478	greg	1.17	for (x = 0; x < hresolu; x++)
479	greg	1.8	if (zscan(y)[x] <= 0) { /* empty pixel */
480	greg	1.7	/*
481			* First, find background from above or below.
482			* (farthest assigned pixel)
483			*/
484	greg	1.4	if (yback[x] == -2) {
485	greg	1.17	for (i = y+1; i < vresolu; i++)
486	greg	1.8	if (zscan(i)[x] > 0)
487	greg	1.4	break;
488	greg	1.17	if (i < vresolu
489	greg	1.2	&& (y <= 0 \|\| zscan(y-1)[x] < zscan(i)[x]))
490	greg	1.4	yback[x] = i;
491			else
492			yback[x] = y-1;
493	greg	1.2	}
494	greg	1.7	/*
495			* Next, find background from left or right.
496			*/
497	greg	1.4	if (xback == -2) {
498	greg	1.17	for (i = x+1; i < hresolu; i++)
499	greg	1.8	if (zscan(y)[i] > 0)
500	greg	1.4	break;
501	greg	1.17	if (i < hresolu
502	greg	1.4	&& (x <= 0 \|\| zscan(y)[x-1] < zscan(y)[i]))
503			xback = i;
504			else
505			xback = x-1;
506			}
507	greg	1.7	/*
508	greg	1.11	* Check to see if we have no background for
509			* this pixel. If not, use background color.
510			*/
511			if (xback < 0 && yback[x] < 0) {
512	greg	1.12	(*deffill)(x,y);
513	greg	1.11	continue;
514			}
515			/*
516	greg	1.7	* Compare, and use the background that is
517			* farther, unless one of them is next to us.
518			*/
519	greg	1.11	if ( yback[x] < 0
520			\|\| (xback >= 0 && ABS(x-xback) <= 1)
521	greg	1.4	\|\| ( ABS(y-yback[x]) > 1
522	greg	1.11	&& zscan(yback[x])[x]
523	greg	1.13	< zscan(y)[xback] ) ) {
524	greg	1.4	copycolr(pscan(y)[x],pscan(y)[xback]);
525	greg	1.13	zscan(y)[x] = zscan(y)[xback];
526			} else {
527	greg	1.4	copycolr(pscan(y)[x],pscan(yback[x])[x]);
528	greg	1.13	zscan(y)[x] = zscan(yback[x])[x];
529			}
530	greg	1.4	} else { /* full pixel */
531			yback[x] = -2;
532			xback = -2;
533			}
534			}
535	greg	1.2	free((char *)yback);
536	greg	1.1	}
537
538
539	greg	1.12	fillpicture() /* paint in empty pixels with default */
540	greg	1.11	{
541			register int x, y;
542
543	greg	1.17	for (y = 0; y < vresolu; y++)
544			for (x = 0; x < hresolu; x++)
545	greg	1.11	if (zscan(y)[x] <= 0)
546	greg	1.12	(*deffill)(x,y);
547	greg	1.11	}
548
549
550	greg	1.1	writepicture() /* write out picture */
551			{
552			int y;
553
554	greg	1.17	fputresolu(YMAJOR\|YDECR, hresolu, vresolu, stdout);
555			for (y = vresolu-1; y >= 0; y--)
556			if (fwritecolrs(pscan(y), hresolu, stdout) < 0)
557	greg	1.15	syserror();
558	greg	1.11	}
559
560
561			writedistance(fname) /* write out z file */
562			char *fname;
563			{
564			extern double sqrt();
565			int donorm = normdist && ourview.type == VT_PER;
566	greg	1.19	int fd;
567	greg	1.11	int y;
568			float *zout;
569
570	greg	1.19	if ((fd = open(fname, O_WRONLY\|O_CREAT\|O_TRUNC, 0666)) == -1) {
571	greg	1.11	perror(fname);
572			exit(1);
573			}
574			if (donorm
575	greg	1.17	&& (zout = (float )malloc(hresolusizeof(float))) == NULL)
576	greg	1.15	syserror();
577	greg	1.17	for (y = vresolu-1; y >= 0; y--) {
578	greg	1.11	if (donorm) {
579			double vx, yzn2;
580			register int x;
581	greg	1.17	yzn2 = y - .5*(vresolu-1);
582			yzn2 = 1. + yzn2yzn2ourview.vn2;
583			for (x = 0; x < hresolu; x++) {
584			vx = x - .5*(hresolu-1);
585	greg	1.11	zout[x] = zscan(y)[x]
586	greg	1.17	* sqrt(vxvxourview.hn2 + yzn2);
587	greg	1.11	}
588			} else
589			zout = zscan(y);
590	greg	1.19	if (write(fd, zout, hresolu*sizeof(float))
591			< hresolu*sizeof(float)) {
592	greg	1.11	perror(fname);
593			exit(1);
594			}
595			}
596			if (donorm)
597			free((char *)zout);
598	greg	1.19	close(fd);
599	greg	1.10	}
600
601
602			isfloat(s) /* see if string is floating number */
603			register char *s;
604			{
605			for ( ; *s; s++)
606			if ((s < '0' \|\| s > '9') && s != '.' && s != '-'
607			&& s != 'e' && s != 'E' && *s != '+')
608			return(0);
609			return(1);
610	greg	1.12	}
611
612
613			backfill(x, y) /* fill pixel with background */
614			int x, y;
615			{
616			register BYTE *dest = pscan(y)[x];
617
618			copycolr(dest, backcolr);
619	greg	1.13	zscan(y)[x] = backz;
620			}
621
622
623			calstart(prog, args) /* start fill calculation */
624			char prog, args;
625			{
626			char combuf[512];
627			int p0[2], p1[2];
628
629	greg	1.14	if (childpid != -1) {
630			fprintf(stderr, "%s: too many calculations\n", progname);
631			exit(1);
632			}
633	greg	1.13	sprintf(combuf, prog, PACKSIZ, args);
634			if (pipe(p0) < 0 \|\| pipe(p1) < 0)
635	greg	1.14	syserror();
636	greg	1.13	if ((childpid = vfork()) == 0) { /* fork calculation */
637			close(p0[1]);
638			close(p1[0]);
639			if (p0[0] != 0) {
640			dup2(p0[0], 0);
641			close(p0[0]);
642			}
643			if (p1[1] != 1) {
644			dup2(p1[1], 1);
645			close(p1[1]);
646			}
647			execl("/bin/sh", "sh", "-c", combuf, 0);
648			perror("/bin/sh");
649			_exit(127);
650			}
651	greg	1.14	if (childpid == -1)
652			syserror();
653	greg	1.13	close(p0[0]);
654			close(p1[1]);
655			if ((psend = fdopen(p0[1], "w")) == NULL)
656	greg	1.14	syserror();
657	greg	1.13	if ((precv = fdopen(p1[0], "r")) == NULL)
658	greg	1.14	syserror();
659	greg	1.13	queuesiz = 0;
660			}
661
662
663			caldone() /* done with calculation */
664			{
665			int pid;
666
667	greg	1.14	if (childpid == -1)
668			return;
669			if (fclose(psend) == EOF)
670			syserror();
671	greg	1.13	clearqueue();
672			fclose(precv);
673			while ((pid = wait(0)) != -1 && pid != childpid)
674			;
675	greg	1.14	childpid = -1;
676	greg	1.13	}
677
678
679	greg	1.14	rcalfill(x, y) /* fill with ray-calculated pixel */
680	greg	1.13	int x, y;
681			{
682			FVECT orig, dir;
683			float outbuf[6];
684
685			if (queuesiz >= PACKSIZ) { /* flush queue */
686	greg	1.14	if (fflush(psend) == EOF)
687			syserror();
688	greg	1.13	clearqueue();
689			}
690			/* send new ray */
691	greg	1.17	viewray(orig, dir, &ourview, (x+.5)/hresolu, (y+.5)/vresolu);
692	greg	1.13	outbuf[0] = orig[0]; outbuf[1] = orig[1]; outbuf[2] = orig[2];
693			outbuf[3] = dir[0]; outbuf[4] = dir[1]; outbuf[5] = dir[2];
694	greg	1.14	if (fwrite(outbuf, sizeof(float), 6, psend) < 6)
695			syserror();
696	greg	1.13	/* remember it */
697			queue[queuesiz][0] = x;
698			queue[queuesiz][1] = y;
699			queuesiz++;
700			}
701
702
703			clearqueue() /* get results from queue */
704			{
705			float inbuf[4];
706			register int i;
707
708			for (i = 0; i < queuesiz; i++) {
709	greg	1.14	if (fread(inbuf, sizeof(float), 4, precv) < 4) {
710			fprintf(stderr, "%s: read error in clearqueue\n",
711			progname);
712			exit(1);
713	greg	1.16	}
714			if (ourexp > 0 && ourexp != 1.0) {
715			inbuf[0] *= ourexp;
716			inbuf[1] *= ourexp;
717			inbuf[2] *= ourexp;
718	greg	1.14	}
719	greg	1.13	setcolr(pscan(queue[i][1])[queue[i][0]],
720			inbuf[0], inbuf[1], inbuf[2]);
721			zscan(queue[i][1])[queue[i][0]] = inbuf[3];
722			}
723			queuesiz = 0;
724	greg	1.14	}
725
726
727			syserror() /* report error and exit */
728			{
729			perror(progname);
730			exit(1);
731	greg	1.1	}