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 "view.h"

#include "color.h"

#define pscan(y)        (ourpict+(y)*ourview.hresolu)
#define zscan(y)        (ourzbuf+(y)*ourview.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(512);         /* desired view */

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

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

char    *progname;

VIEW    theirview = STDVIEW(512);       /* input view */
int     gotview;                        /* got input view? */

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 */

double  theirs2ours[4][4];              /* transformation matrix */
int     normdist = 1;                   /* normalized distance? */

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;

        progname = argv[0];

        for (i = 1; i < argc && argv[i][0] == '-'; i++)
                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);
                        ourview.hresolu = atoi(argv[++i]);
                        break;
                case 'y':                               /* y resolution */
                        check(2,1);
                        ourview.vresolu = atoi(argv[++i]);
                        break;
                case 'v':                               /* view */
                        switch (argv[i][2]) {
                        case 't':                               /* type */
                                check(4,0);
                                ourview.type = argv[i][3];
                                break;
                        case 'p':                               /* point */
                                check(3,3);
                                ourview.vp[0] = atof(argv[++i]);
                                ourview.vp[1] = atof(argv[++i]);
                                ourview.vp[2] = atof(argv[++i]);
                                break;
                        case 'd':                               /* direction */
                                check(3,3);
                                ourview.vdir[0] = atof(argv[++i]);
                                ourview.vdir[1] = atof(argv[++i]);
                                ourview.vdir[2] = atof(argv[++i]);
                                break;
                        case 'u':                               /* up */
                                check(3,3);
                                ourview.vup[0] = atof(argv[++i]);
                                ourview.vup[1] = atof(argv[++i]);
                                ourview.vup[2] = atof(argv[++i]);
                                break;
                        case 'h':                               /* horizontal */
                                check(3,1);
                                ourview.horiz = atof(argv[++i]);
                                break;
                        case 'v':                               /* vertical */
                                check(3,1);
                                ourview.vert = atof(argv[++i]);
                                break;
                        case 'f':                               /* file */
                                check(3,1);
                                gotvfile = viewfile(argv[++i], &ourview);
                                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:
                                goto badopt;
                        }
                        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);
        }
                                                /* allocate frame */
        ourpict = (COLR *)malloc(ourview.hresolu*ourview.vresolu*sizeof(COLR));
        ourzbuf = (float *)calloc(ourview.hresolu*ourview.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");
        }
        printf("\n");
                                                        /* write picture */
        writepicture();
                                                        /* write z file */
        if (zfile != NULL)
                writedistance(zfile);

        exit(0);
userr:
        fprintf(stderr,
        "Usage: %s [view opts][-t zthresh][-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);

        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, *zfp;
        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 and view */
        printf("%s:\n", pfile);
        gotview = 0;
        getheader(pfp, headline);
        if (!gotview || fgetresolu(&theirview.hresolu, &theirview.vresolu, pfp)
                        != (YMAJOR|YDECR)) {
                fprintf(stderr, "%s: picture view error\n", pfile);
                exit(1);
        }
        if (err = setview(&theirview)) {
                fprintf(stderr, "%s: %s\n", pfile, err);
                exit(1);
        }
                                        /* compute transformation */
        pixform(theirs2ours, &theirview, &ourview);
                                        /* allocate scanlines */
        scanin = (COLR *)malloc(theirview.hresolu*sizeof(COLR));
        zin = (float *)malloc(theirview.hresolu*sizeof(float));
        plast = (struct position *)calloc(theirview.hresolu,
                                                sizeof(struct position));
        if (scanin == NULL || zin == NULL || plast == NULL)
                syserror();
                                        /* get z specification or file */
        if ((zfp = fopen(zspec, "r")) == NULL) {
                double  zvalue;
                register int    x;
                if (!isfloat(zspec) || (zvalue = atof(zspec)) <= 0.0) {
                        perror(zspec);
                        exit(1);
                }
                for (x = 0; x < theirview.hresolu; x++)
                        zin[x] = zvalue;
        }
                                        /* load image */
        for (y = theirview.vresolu-1; y >= 0; y--) {
                if (freadcolrs(scanin, theirview.hresolu, pfp) < 0) {
                        fprintf(stderr, "%s: read error\n", pfile);
                        exit(1);
                }
                if (zfp != NULL
                        && fread(zin,sizeof(float),theirview.hresolu,zfp)
                                < theirview.hresolu) {
                        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 (zfp != NULL)
                fclose(zfp);
}


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->vhinc[0];
        xfmat[0][1] = vw1->vhinc[1];
        xfmat[0][2] = vw1->vhinc[2];
        xfmat[1][0] = vw1->vvinc[0];
        xfmat[1][1] = vw1->vvinc[1];
        xfmat[1][2] = vw1->vvinc[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->vhinc[0]/vw2->vhn2;
        m4t[1][0] = vw2->vhinc[1]/vw2->vhn2;
        m4t[2][0] = vw2->vhinc[2]/vw2->vhn2;
        m4t[3][0] = -DOT(vw2->vp,vw2->vhinc)/vw2->vhn2;
        m4t[0][1] = vw2->vvinc[0]/vw2->vvn2;
        m4t[1][1] = vw2->vvinc[1]/vw2->vvn2;
        m4t[2][1] = vw2->vvinc[2]/vw2->vvn2;
        m4t[3][1] = -DOT(vw2->vp,vw2->vvinc)/vw2->vvn2;
        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 = theirview.hresolu-1; x >= 0; x--) {
                pos[0] = x - .5*(theirview.hresolu-1);
                pos[1] = y - .5*(theirview.vresolu-1);
                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.vhn2
                                        + pos[1]*pos[1]*theirview.vvn2 );
                        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.hresolu;
                pos[1] += .5*ourview.vresolu;
                newpos.x = pos[0];
                newpos.y = pos[1];
                newpos.z = zline[x];
                                        /* add pixel to our image */
                if (pos[0] >= 0 && newpos.x < ourview.hresolu
                                && pos[1] >= 0 && newpos.y < ourview.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(ourview.hresolu*sizeof(int));
        if (yback == NULL)
                syserror();
        for (x = 0; x < ourview.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 < ourview.vresolu; y++) {
                xback = -2;
                for (x = 0; x < ourview.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 < ourview.vresolu; i++)
                                                if (zscan(i)[x] > 0)
                                                        break;
                                        if (i < ourview.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 < ourview.hresolu; i++)
                                                if (zscan(y)[i] > 0)
                                                        break;
                                        if (i < ourview.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 < ourview.vresolu; y++)
                for (x = 0; x < ourview.hresolu; x++)
                        if (zscan(y)[x] <= 0)
                                (*deffill)(x,y);
}


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

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


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

        if ((fp = fopen(fname, "w")) == NULL) {
                perror(fname);
                exit(1);
        }
        if (donorm
        && (zout = (float *)malloc(ourview.hresolu*sizeof(float))) == NULL)
                syserror();
        for (y = ourview.vresolu-1; y >= 0; y--) {
                if (donorm) {
                        double  vx, yzn2;
                        register int    x;
                        yzn2 = y - .5*(ourview.vresolu-1);
                        yzn2 = 1. + yzn2*yzn2*ourview.vvn2;
                        for (x = 0; x < ourview.hresolu; x++) {
                                vx = x - .5*(ourview.hresolu-1);
                                zout[x] = zscan(y)[x]
                                        * sqrt(vx*vx*ourview.vhn2 + yzn2);
                        }
                } else
                        zout = zscan(y);
                if (fwrite(zout, sizeof(float), ourview.hresolu, fp)
                                < ourview.hresolu) {
                        perror(fname);
                        exit(1);
                }
        }
        if (donorm)
                free((char *)zout);
        fclose(fp);
}


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 */
        rayview(orig, dir, &ourview, x+.5, y+.5);
        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);
                }
                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:	1.15
Committed:	Fri Jan 5 11:34:27 1990 UTC (34 years, 3 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.14:	+78 -67 lines
Log Message:	changed addpixel() to fill parallelogram
#	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			#include "view.h"
14
15			#include "color.h"
16
17			#define pscan(y) (ourpict+(y)*ourview.hresolu)
18			#define zscan(y) (ourzbuf+(y)*ourview.hresolu)
19
20	greg	1.13	#define F_FORE 1 /* fill foreground */
21			#define F_BACK 2 /* fill background */
22	greg	1.11
23	greg	1.13	#define PACKSIZ 42 /* calculation packet size */
24
25			#define RTCOM "rtrace -h -ovl -fff -x %d %s"
26
27	greg	1.3	#define ABS(x) ((x)>0?(x):-(x))
28
29	greg	1.15	struct position {int x,y; float z;};
30
31	greg	1.1	VIEW ourview = STDVIEW(512); /* desired view */
32
33	greg	1.8	double zeps = .02; /* allowed z epsilon */
34	greg	1.1
35			COLR ourpict; / output picture */
36			float ourzbuf; / corresponding z-buffer */
37
38			char *progname;
39
40			VIEW theirview = STDVIEW(512); /* input view */
41			int gotview; /* got input view? */
42
43	greg	1.12	int fill = F_FORE\|F_BACK; /* selected fill algorithm */
44	greg	1.14	extern int backfill(), rcalfill(); /* fill functions */
45	greg	1.12	int (deffill)() = backfill; / selected fill function */
46	greg	1.11	COLR backcolr = BLKCOLR; /* background color */
47	greg	1.13	double backz = 0.0; /* background z value */
48	greg	1.11
49	greg	1.5	double theirs2ours[4][4]; /* transformation matrix */
50	greg	1.11	int normdist = 1; /* normalized distance? */
51	greg	1.1
52	greg	1.14	int childpid = -1; /* id of fill process */
53	greg	1.13	FILE psend, precv; /* pipes to/from fill calculation */
54			int queue[PACKSIZ][2]; /* pending pixels */
55			int queuesiz; /* number of pixels pending */
56	greg	1.5
57	greg	1.13
58	greg	1.1	main(argc, argv) /* interpolate pictures */
59			int argc;
60			char *argv[];
61			{
62			#define check(olen,narg) if (argv[i][olen] \|\| narg >= argc-i) goto badopt
63	greg	1.11	extern double atof();
64	greg	1.1	int gotvfile = 0;
65	greg	1.11	char *zfile = NULL;
66	greg	1.1	char *err;
67			int i;
68
69			progname = argv[0];
70
71			for (i = 1; i < argc && argv[i][0] == '-'; i++)
72			switch (argv[i][1]) {
73			case 't': /* threshold */
74			check(2,1);
75			zeps = atof(argv[++i]);
76			break;
77	greg	1.11	case 'n': /* dist. normalized? */
78	greg	1.10	check(2,0);
79	greg	1.11	normdist = !normdist;
80	greg	1.10	break;
81	greg	1.11	case 'f': /* fill type */
82			switch (argv[i][2]) {
83			case '0': /* none */
84			check(3,0);
85			fill = 0;
86			break;
87			case 'f': /* foreground */
88			check(3,0);
89			fill = F_FORE;
90			break;
91			case 'b': /* background */
92			check(3,0);
93			fill = F_BACK;
94			break;
95			case 'a': /* all */
96			check(3,0);
97			fill = F_FORE\|F_BACK;
98			break;
99			case 'c': /* color */
100			check(3,3);
101	greg	1.12	deffill = backfill;
102	greg	1.11	setcolr(backcolr, atof(argv[i+1]),
103			atof(argv[i+2]), atof(argv[i+3]));
104			i += 3;
105			break;
106	greg	1.13	case 'z': /* z value */
107			check(3,1);
108			deffill = backfill;
109			backz = atof(argv[++i]);
110			break;
111			case 'r': /* rtrace */
112			check(3,1);
113	greg	1.14	deffill = rcalfill;
114	greg	1.13	calstart(RTCOM, argv[++i]);
115			break;
116	greg	1.11	default:
117			goto badopt;
118			}
119			break;
120			case 'z': /* z file */
121			check(2,1);
122			zfile = argv[++i];
123			break;
124	greg	1.6	case 'x': /* x resolution */
125			check(2,1);
126			ourview.hresolu = atoi(argv[++i]);
127			break;
128			case 'y': /* y resolution */
129			check(2,1);
130			ourview.vresolu = atoi(argv[++i]);
131			break;
132	greg	1.1	case 'v': /* view */
133			switch (argv[i][2]) {
134			case 't': /* type */
135			check(4,0);
136			ourview.type = argv[i][3];
137			break;
138			case 'p': /* point */
139			check(3,3);
140			ourview.vp[0] = atof(argv[++i]);
141			ourview.vp[1] = atof(argv[++i]);
142			ourview.vp[2] = atof(argv[++i]);
143			break;
144			case 'd': /* direction */
145			check(3,3);
146			ourview.vdir[0] = atof(argv[++i]);
147			ourview.vdir[1] = atof(argv[++i]);
148			ourview.vdir[2] = atof(argv[++i]);
149			break;
150			case 'u': /* up */
151			check(3,3);
152			ourview.vup[0] = atof(argv[++i]);
153			ourview.vup[1] = atof(argv[++i]);
154			ourview.vup[2] = atof(argv[++i]);
155			break;
156			case 'h': /* horizontal */
157			check(3,1);
158			ourview.horiz = atof(argv[++i]);
159			break;
160			case 'v': /* vertical */
161			check(3,1);
162			ourview.vert = atof(argv[++i]);
163			break;
164			case 'f': /* file */
165			check(3,1);
166			gotvfile = viewfile(argv[++i], &ourview);
167			if (gotvfile < 0) {
168			perror(argv[i]);
169			exit(1);
170			} else if (gotvfile == 0) {
171			fprintf(stderr, "%s: bad view file\n",
172			argv[i]);
173			exit(1);
174			}
175			break;
176			default:
177			goto badopt;
178			}
179			break;
180			default:
181			badopt:
182	greg	1.10	fprintf(stderr, "%s: command line error at '%s'\n",
183	greg	1.1	progname, argv[i]);
184	greg	1.10	goto userr;
185	greg	1.1	}
186			/* check arguments */
187	greg	1.13	if ((argc-i)%2)
188	greg	1.10	goto userr;
189	greg	1.1	/* set view */
190			if (err = setview(&ourview)) {
191			fprintf(stderr, "%s: %s\n", progname, err);
192			exit(1);
193			}
194			/* allocate frame */
195	greg	1.12	ourpict = (COLR )malloc(ourview.hresoluourview.vresolu*sizeof(COLR));
196	greg	1.1	ourzbuf = (float )calloc(ourview.hresoluourview.vresolu,sizeof(float));
197	greg	1.15	if (ourpict == NULL \|\| ourzbuf == NULL)
198			syserror();
199	greg	1.1	/* get input */
200			for ( ; i < argc; i += 2)
201			addpicture(argv[i], argv[i+1]);
202			/* fill in spaces */
203	greg	1.11	if (fill&F_BACK)
204	greg	1.12	backpicture();
205			else
206	greg	1.11	fillpicture();
207	greg	1.13	/* close calculation */
208	greg	1.14	caldone();
209	greg	1.1	/* add to header */
210			printargs(argc, argv, stdout);
211			if (gotvfile) {
212			printf(VIEWSTR);
213			fprintview(&ourview, stdout);
214			printf("\n");
215			}
216			printf("\n");
217	greg	1.11	/* write picture */
218	greg	1.1	writepicture();
219	greg	1.11	/* write z file */
220			if (zfile != NULL)
221			writedistance(zfile);
222	greg	1.1
223			exit(0);
224	greg	1.10	userr:
225			fprintf(stderr,
226	greg	1.11	"Usage: %s [view opts][-t zthresh][-z zout][-fT][-n] pfile zspec ..\n",
227	greg	1.10	progname);
228			exit(1);
229	greg	1.1	#undef check
230			}
231
232
233			headline(s) /* process header string */
234			char *s;
235			{
236			static char *altname[] = {"rview","rpict","pinterp",VIEWSTR,NULL};
237			register char **an;
238
239			printf("\t%s", s);
240
241			for (an = altname; *an != NULL; an++)
242			if (!strncmp(an, s, strlen(an))) {
243			if (sscanview(&theirview, s+strlen(*an)) == 0)
244			gotview++;
245			break;
246			}
247			}
248
249
250	greg	1.10	addpicture(pfile, zspec) /* add picture to output */
251			char pfile, zspec;
252	greg	1.1	{
253	greg	1.10	extern double atof();
254	greg	1.1	FILE pfp, zfp;
255	greg	1.8	char *err;
256	greg	1.1	COLR *scanin;
257	greg	1.15	float *zin;
258			struct position *plast;
259	greg	1.1	int y;
260	greg	1.10	/* open picture file */
261	greg	1.1	if ((pfp = fopen(pfile, "r")) == NULL) {
262			perror(pfile);
263			exit(1);
264			}
265			/* get header and view */
266			printf("%s:\n", pfile);
267			gotview = 0;
268			getheader(pfp, headline);
269	greg	1.9	if (!gotview \|\| fgetresolu(&theirview.hresolu, &theirview.vresolu, pfp)
270			!= (YMAJOR\|YDECR)) {
271	greg	1.1	fprintf(stderr, "%s: picture view error\n", pfile);
272			exit(1);
273			}
274			if (err = setview(&theirview)) {
275			fprintf(stderr, "%s: %s\n", pfile, err);
276			exit(1);
277			}
278	greg	1.5	/* compute transformation */
279			pixform(theirs2ours, &theirview, &ourview);
280	greg	1.1	/* allocate scanlines */
281	greg	1.9	scanin = (COLR )malloc(theirview.hresolusizeof(COLR));
282			zin = (float )malloc(theirview.hresolusizeof(float));
283	greg	1.15	plast = (struct position *)calloc(theirview.hresolu,
284			sizeof(struct position));
285			if (scanin == NULL \|\| zin == NULL \|\| plast == NULL)
286			syserror();
287	greg	1.10	/* get z specification or file */
288			if ((zfp = fopen(zspec, "r")) == NULL) {
289			double zvalue;
290			register int x;
291			if (!isfloat(zspec) \|\| (zvalue = atof(zspec)) <= 0.0) {
292			perror(zspec);
293			exit(1);
294			}
295			for (x = 0; x < theirview.hresolu; x++)
296			zin[x] = zvalue;
297			}
298	greg	1.1	/* load image */
299	greg	1.9	for (y = theirview.vresolu-1; y >= 0; y--) {
300			if (freadcolrs(scanin, theirview.hresolu, pfp) < 0) {
301	greg	1.1	fprintf(stderr, "%s: read error\n", pfile);
302			exit(1);
303			}
304	greg	1.10	if (zfp != NULL
305			&& fread(zin,sizeof(float),theirview.hresolu,zfp)
306	greg	1.9	< theirview.hresolu) {
307	greg	1.10	fprintf(stderr, "%s: read error\n", zspec);
308	greg	1.1	exit(1);
309			}
310	greg	1.15	addscanline(y, scanin, zin, plast);
311	greg	1.1	}
312			/* clean up */
313			free((char *)scanin);
314			free((char *)zin);
315	greg	1.9	free((char *)plast);
316	greg	1.1	fclose(pfp);
317	greg	1.10	if (zfp != NULL)
318			fclose(zfp);
319	greg	1.1	}
320
321
322	greg	1.5	pixform(xfmat, vw1, vw2) /* compute view1 to view2 matrix */
323			register double xfmat[4][4];
324			register VIEW vw1, vw2;
325			{
326			double m4t[4][4];
327
328			setident4(xfmat);
329			xfmat[0][0] = vw1->vhinc[0];
330			xfmat[0][1] = vw1->vhinc[1];
331			xfmat[0][2] = vw1->vhinc[2];
332			xfmat[1][0] = vw1->vvinc[0];
333			xfmat[1][1] = vw1->vvinc[1];
334			xfmat[1][2] = vw1->vvinc[2];
335			xfmat[2][0] = vw1->vdir[0];
336			xfmat[2][1] = vw1->vdir[1];
337			xfmat[2][2] = vw1->vdir[2];
338			xfmat[3][0] = vw1->vp[0];
339			xfmat[3][1] = vw1->vp[1];
340			xfmat[3][2] = vw1->vp[2];
341			setident4(m4t);
342			m4t[0][0] = vw2->vhinc[0]/vw2->vhn2;
343			m4t[1][0] = vw2->vhinc[1]/vw2->vhn2;
344			m4t[2][0] = vw2->vhinc[2]/vw2->vhn2;
345			m4t[3][0] = -DOT(vw2->vp,vw2->vhinc)/vw2->vhn2;
346			m4t[0][1] = vw2->vvinc[0]/vw2->vvn2;
347			m4t[1][1] = vw2->vvinc[1]/vw2->vvn2;
348			m4t[2][1] = vw2->vvinc[2]/vw2->vvn2;
349			m4t[3][1] = -DOT(vw2->vp,vw2->vvinc)/vw2->vvn2;
350			m4t[0][2] = vw2->vdir[0];
351			m4t[1][2] = vw2->vdir[1];
352			m4t[2][2] = vw2->vdir[2];
353			m4t[3][2] = -DOT(vw2->vp,vw2->vdir);
354			multmat4(xfmat, xfmat, m4t);
355			}
356
357
358	greg	1.15	addscanline(y, pline, zline, lasty) /* add scanline to output */
359	greg	1.1	int y;
360			COLR *pline;
361			float *zline;
362	greg	1.15	struct position lasty; / input/output */
363	greg	1.1	{
364	greg	1.11	extern double sqrt();
365	greg	1.5	double pos[3];
366	greg	1.15	struct position lastx, newpos;
367	greg	1.1	register int x;
368
369	greg	1.8	for (x = theirview.hresolu-1; x >= 0; x--) {
370	greg	1.5	pos[0] = x - .5*(theirview.hresolu-1);
371			pos[1] = y - .5*(theirview.vresolu-1);
372			pos[2] = zline[x];
373			if (theirview.type == VT_PER) {
374	greg	1.11	if (normdist) /* adjust for eye-ray distance */
375	greg	1.10	pos[2] /= sqrt( 1.
376	greg	1.5	+ pos[0]pos[0]theirview.vhn2
377			+ pos[1]pos[1]theirview.vvn2 );
378			pos[0] *= pos[2];
379			pos[1] *= pos[2];
380			}
381			multp3(pos, pos, theirs2ours);
382	greg	1.15	if (pos[2] <= 0) {
383			lasty[x].z = lastx.z = 0; /* mark invalid */
384	greg	1.1	continue;
385	greg	1.15	}
386	greg	1.5	if (ourview.type == VT_PER) {
387			pos[0] /= pos[2];
388			pos[1] /= pos[2];
389			}
390			pos[0] += .5*ourview.hresolu;
391			pos[1] += .5*ourview.vresolu;
392	greg	1.15	newpos.x = pos[0];
393			newpos.y = pos[1];
394			newpos.z = zline[x];
395	greg	1.8	/* add pixel to our image */
396	greg	1.15	if (pos[0] >= 0 && newpos.x < ourview.hresolu
397			&& pos[1] >= 0 && newpos.y < ourview.vresolu) {
398			addpixel(&newpos, &lastx, &lasty[x], pline[x], pos[2]);
399			lasty[x].x = lastx.x = newpos.x;
400			lasty[x].y = lastx.y = newpos.y;
401			lasty[x].z = lastx.z = newpos.z;
402			} else
403			lasty[x].z = lastx.z = 0; /* mark invalid */
404	greg	1.1	}
405			}
406
407
408	greg	1.15	addpixel(p0, p1, p2, pix, z) /* fill in pixel parallelogram */
409			struct position p0, p1, *p2;
410	greg	1.8	COLR pix;
411			double z;
412			{
413	greg	1.15	double zt = 2.zepsp0->z; /* threshold */
414			int s1x, s1y, s2x, s2y; /* step sizes */
415			int l1, l2, c1, c2; /* side lengths and counters */
416			int p1isy; /* p0p1 along y? */
417			int x1, y1; /* p1 position */
418			register int x, y; /* final position */
419
420			/* compute vector p0p1 */
421			if (fill&F_FORE && ABS(p1->z-p0->z) <= zt) {
422			s1x = p1->x - p0->x;
423			s1y = p1->y - p0->y;
424			l1 = ABS(s1x);
425			if (p1isy = (ABS(s1y) > l1))
426			l1 = ABS(s1y);
427			} else {
428			l1 = s1x = s1y = 1;
429			p1isy = -1;
430			}
431			/* compute vector p0p2 */
432			if (fill&F_FORE && ABS(p2->z-p0->z) <= zt) {
433			s2x = p2->x - p0->x;
434			s2y = p2->y - p0->y;
435			if (p1isy == 1)
436			l2 = ABS(s2x);
437			else {
438			l2 = ABS(s2y);
439			if (p1isy != 0 && ABS(s2x) > l2)
440			l2 = ABS(s2x);
441			}
442			} else
443			l2 = s2x = s2y = 1;
444			/* fill the parallelogram */
445			for (c1 = l1; c1-- > 0; ) {
446			x1 = p0->x + c1*s1x/l1;
447			y1 = p0->y + c1*s1y/l1;
448			for (c2 = l2; c2-- > 0; ) {
449			x = x1 + c2*s2x/l2;
450			y = y1 + c2*s2y/l2;
451			if (zscan(y)[x] <= 0 \|\| zscan(y)[x]-z
452			> zeps*zscan(y)[x]) {
453	greg	1.8	zscan(y)[x] = z;
454			copycolr(pscan(y)[x], pix);
455			}
456	greg	1.15	}
457			}
458	greg	1.8	}
459
460
461	greg	1.12	backpicture() /* background fill algorithm */
462	greg	1.1	{
463	greg	1.2	int *yback, xback;
464	greg	1.1	int y;
465	greg	1.2	COLR pfill;
466			register int x, i;
467			/* get back buffer */
468			yback = (int )malloc(ourview.hresolusizeof(int));
469	greg	1.15	if (yback == NULL)
470			syserror();
471	greg	1.2	for (x = 0; x < ourview.hresolu; x++)
472	greg	1.4	yback[x] = -2;
473	greg	1.7	/*
474			* Xback and yback are the pixel locations of suitable
475			* background values in each direction.
476			* A value of -2 means unassigned, and -1 means
477			* that there is no suitable background in this direction.
478			*/
479	greg	1.2	/* fill image */
480	greg	1.4	for (y = 0; y < ourview.vresolu; y++) {
481			xback = -2;
482	greg	1.1	for (x = 0; x < ourview.hresolu; x++)
483	greg	1.8	if (zscan(y)[x] <= 0) { /* empty pixel */
484	greg	1.7	/*
485			* First, find background from above or below.
486			* (farthest assigned pixel)
487			*/
488	greg	1.4	if (yback[x] == -2) {
489			for (i = y+1; i < ourview.vresolu; i++)
490	greg	1.8	if (zscan(i)[x] > 0)
491	greg	1.4	break;
492			if (i < ourview.vresolu
493	greg	1.2	&& (y <= 0 \|\| zscan(y-1)[x] < zscan(i)[x]))
494	greg	1.4	yback[x] = i;
495			else
496			yback[x] = y-1;
497	greg	1.2	}
498	greg	1.7	/*
499			* Next, find background from left or right.
500			*/
501	greg	1.4	if (xback == -2) {
502	greg	1.11	for (i = x+1; i < ourview.hresolu; i++)
503	greg	1.8	if (zscan(y)[i] > 0)
504	greg	1.4	break;
505			if (i < ourview.hresolu
506			&& (x <= 0 \|\| zscan(y)[x-1] < zscan(y)[i]))
507			xback = i;
508			else
509			xback = x-1;
510			}
511	greg	1.7	/*
512	greg	1.11	* Check to see if we have no background for
513			* this pixel. If not, use background color.
514			*/
515			if (xback < 0 && yback[x] < 0) {
516	greg	1.12	(*deffill)(x,y);
517	greg	1.11	continue;
518			}
519			/*
520	greg	1.7	* Compare, and use the background that is
521			* farther, unless one of them is next to us.
522			*/
523	greg	1.11	if ( yback[x] < 0
524			\|\| (xback >= 0 && ABS(x-xback) <= 1)
525	greg	1.4	\|\| ( ABS(y-yback[x]) > 1
526	greg	1.11	&& zscan(yback[x])[x]
527	greg	1.13	< zscan(y)[xback] ) ) {
528	greg	1.4	copycolr(pscan(y)[x],pscan(y)[xback]);
529	greg	1.13	zscan(y)[x] = zscan(y)[xback];
530			} else {
531	greg	1.4	copycolr(pscan(y)[x],pscan(yback[x])[x]);
532	greg	1.13	zscan(y)[x] = zscan(yback[x])[x];
533			}
534	greg	1.4	} else { /* full pixel */
535			yback[x] = -2;
536			xback = -2;
537			}
538			}
539	greg	1.2	free((char *)yback);
540	greg	1.1	}
541
542
543	greg	1.12	fillpicture() /* paint in empty pixels with default */
544	greg	1.11	{
545			register int x, y;
546
547			for (y = 0; y < ourview.vresolu; y++)
548			for (x = 0; x < ourview.hresolu; x++)
549			if (zscan(y)[x] <= 0)
550	greg	1.12	(*deffill)(x,y);
551	greg	1.11	}
552
553
554	greg	1.1	writepicture() /* write out picture */
555			{
556			int y;
557
558			fputresolu(YMAJOR\|YDECR, ourview.hresolu, ourview.vresolu, stdout);
559			for (y = ourview.vresolu-1; y >= 0; y--)
560	greg	1.15	if (fwritecolrs(pscan(y), ourview.hresolu, stdout) < 0)
561			syserror();
562	greg	1.11	}
563
564
565			writedistance(fname) /* write out z file */
566			char *fname;
567			{
568			extern double sqrt();
569			int donorm = normdist && ourview.type == VT_PER;
570			FILE *fp;
571			int y;
572			float *zout;
573
574			if ((fp = fopen(fname, "w")) == NULL) {
575			perror(fname);
576			exit(1);
577			}
578			if (donorm
579	greg	1.15	&& (zout = (float )malloc(ourview.hresolusizeof(float))) == NULL)
580			syserror();
581	greg	1.11	for (y = ourview.vresolu-1; y >= 0; y--) {
582			if (donorm) {
583			double vx, yzn2;
584			register int x;
585			yzn2 = y - .5*(ourview.vresolu-1);
586			yzn2 = 1. + yzn2yzn2ourview.vvn2;
587			for (x = 0; x < ourview.hresolu; x++) {
588			vx = x - .5*(ourview.hresolu-1);
589			zout[x] = zscan(y)[x]
590			* sqrt(vxvxourview.vhn2 + yzn2);
591			}
592			} else
593			zout = zscan(y);
594			if (fwrite(zout, sizeof(float), ourview.hresolu, fp)
595			< ourview.hresolu) {
596			perror(fname);
597			exit(1);
598			}
599			}
600			if (donorm)
601			free((char *)zout);
602			fclose(fp);
603	greg	1.10	}
604
605
606			isfloat(s) /* see if string is floating number */
607			register char *s;
608			{
609			for ( ; *s; s++)
610			if ((s < '0' \|\| s > '9') && s != '.' && s != '-'
611			&& s != 'e' && s != 'E' && *s != '+')
612			return(0);
613			return(1);
614	greg	1.12	}
615
616
617			backfill(x, y) /* fill pixel with background */
618			int x, y;
619			{
620			register BYTE *dest = pscan(y)[x];
621
622			copycolr(dest, backcolr);
623	greg	1.13	zscan(y)[x] = backz;
624			}
625
626
627			calstart(prog, args) /* start fill calculation */
628			char prog, args;
629			{
630			char combuf[512];
631			int p0[2], p1[2];
632
633	greg	1.14	if (childpid != -1) {
634			fprintf(stderr, "%s: too many calculations\n", progname);
635			exit(1);
636			}
637	greg	1.13	sprintf(combuf, prog, PACKSIZ, args);
638			if (pipe(p0) < 0 \|\| pipe(p1) < 0)
639	greg	1.14	syserror();
640	greg	1.13	if ((childpid = vfork()) == 0) { /* fork calculation */
641			close(p0[1]);
642			close(p1[0]);
643			if (p0[0] != 0) {
644			dup2(p0[0], 0);
645			close(p0[0]);
646			}
647			if (p1[1] != 1) {
648			dup2(p1[1], 1);
649			close(p1[1]);
650			}
651			execl("/bin/sh", "sh", "-c", combuf, 0);
652			perror("/bin/sh");
653			_exit(127);
654			}
655	greg	1.14	if (childpid == -1)
656			syserror();
657	greg	1.13	close(p0[0]);
658			close(p1[1]);
659			if ((psend = fdopen(p0[1], "w")) == NULL)
660	greg	1.14	syserror();
661	greg	1.13	if ((precv = fdopen(p1[0], "r")) == NULL)
662	greg	1.14	syserror();
663	greg	1.13	queuesiz = 0;
664			}
665
666
667			caldone() /* done with calculation */
668			{
669			int pid;
670
671	greg	1.14	if (childpid == -1)
672			return;
673			if (fclose(psend) == EOF)
674			syserror();
675	greg	1.13	clearqueue();
676			fclose(precv);
677			while ((pid = wait(0)) != -1 && pid != childpid)
678			;
679	greg	1.14	childpid = -1;
680	greg	1.13	}
681
682
683	greg	1.14	rcalfill(x, y) /* fill with ray-calculated pixel */
684	greg	1.13	int x, y;
685			{
686			FVECT orig, dir;
687			float outbuf[6];
688
689			if (queuesiz >= PACKSIZ) { /* flush queue */
690	greg	1.14	if (fflush(psend) == EOF)
691			syserror();
692	greg	1.13	clearqueue();
693			}
694			/* send new ray */
695			rayview(orig, dir, &ourview, x+.5, y+.5);
696			outbuf[0] = orig[0]; outbuf[1] = orig[1]; outbuf[2] = orig[2];
697			outbuf[3] = dir[0]; outbuf[4] = dir[1]; outbuf[5] = dir[2];
698	greg	1.14	if (fwrite(outbuf, sizeof(float), 6, psend) < 6)
699			syserror();
700	greg	1.13	/* remember it */
701			queue[queuesiz][0] = x;
702			queue[queuesiz][1] = y;
703			queuesiz++;
704			}
705
706
707			clearqueue() /* get results from queue */
708			{
709			float inbuf[4];
710			register int i;
711
712			for (i = 0; i < queuesiz; i++) {
713	greg	1.14	if (fread(inbuf, sizeof(float), 4, precv) < 4) {
714			fprintf(stderr, "%s: read error in clearqueue\n",
715			progname);
716			exit(1);
717			}
718	greg	1.13	setcolr(pscan(queue[i][1])[queue[i][0]],
719			inbuf[0], inbuf[1], inbuf[2]);
720			zscan(queue[i][1])[queue[i][0]] = inbuf[3];
721			}
722			queuesiz = 0;
723	greg	1.14	}
724
725
726			syserror() /* report error and exit */
727			{
728			perror(progname);
729			exit(1);
730	greg	1.1	}