src/px/pinterp.c

/* Copyright (c) 1999 Silicon Graphics, Inc. */

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

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

#include "standard.h"

#include <ctype.h>

#include "view.h"

#include "color.h"

#include "resolu.h"

#define LOG2            0.69314718055994530942

#define pscan(y)        (ourpict+(y)*hresolu)
#define sscan(y)        (ourspict+(y)*hresolu)
#define wscan(y)        (ourweigh+(y)*hresolu)
#define zscan(y)        (ourzbuf+(y)*hresolu)
#define bscan(y)        (ourbpict+(y)*hresolu)
#define averaging       (ourweigh != NULL)
#define blurring        (ourbpict != NULL)
#define usematrix       (hasmatrix & !averaging)
#define zisnorm         (!usematrix | ourview.type != VT_PER)

#define MAXWT           1000.           /* maximum pixel weight (averaging) */

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

#define PACKSIZ         256             /* max. calculation packet size */

#define RTCOM           "rtrace -h- -ovl -fff -ld- -i- -I- "

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

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

#define NSTEPS          64              /* number steps in overlap prescan */
#define MINSTEP         4               /* minimum worthwhile preview step */

struct bound {int min,max;};

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 (COLR's) */
COLOR   *ourspict;                      /* output pixel sums (averaging) */
float   *ourweigh = NULL;               /* output pixel weights (averaging) */
float   *ourzbuf;                       /* corresponding z-buffer */
COLOR   *ourbpict = NULL;               /* blurred picture (view averaging) */

VIEW    avgview;                        /* average view for -B option */
int     nvavg;                          /* number of views averaged */

char    *progname;

int     fillo = F_FORE|F_BACK;          /* selected fill options */
int     fillsamp = 0;                   /* sample separation (0 == inf) */
extern int      backfill(), rcalfill(); /* fill functions */
int     (*fillfunc)() = backfill;       /* selected fill function */
COLR    backcolr = BLKCOLR;             /* background color */
COLOR   backcolor = BLKCOLOR;           /* background color (float) */
double  backz = 0.0;                    /* background z value */
int     normdist = 1;                   /* i/o normalized distance? */
char    ourfmt[LPICFMT+1] = PICFMT;     /* original picture format */
double  ourexp = -1;                    /* original picture exposure */
int     expadj = 0;                     /* exposure adjustment (f-stops) */
double  rexpadj = 1;                    /* real exposure adjustment */

VIEW    theirview;                      /* input view */
int     gotview;                        /* got input view? */
int     wrongformat = 0;                /* input in another format? */
RESOLU  tresolu;                        /* input resolution */
double  theirexp;                       /* input picture exposure */
MAT4    theirs2ours;                    /* transformation matrix */
int     hasmatrix = 0;                  /* has transformation matrix */

int     PDesc[3] = {-1,-1,-1};          /* rtrace process descriptor */
#define childpid        (PDesc[2])
unsigned short  queue[PACKSIZ][2];      /* pending pixels */
int     packsiz;                        /* actual packet size */
int     queuesiz = 0;                   /* number of pixels pending */

extern double   movepixel();


main(argc, argv)                        /* interpolate pictures */
int     argc;
char    *argv[];
{
#define  check(ol,al)           if (argv[an][ol] || \
                                badarg(argc-an-1,argv+an+1,al)) \
                                goto badopt
        int     gotvfile = 0;
        int     doavg = -1;
        int     doblur = 0;
        char    *zfile = NULL;
        char    *expcomp = NULL;
        int     i, an, rval;

        progname = argv[0];

        for (an = 1; an < argc && argv[an][0] == '-'; an++) {
                rval = getviewopt(&ourview, argc-an, argv+an);
                if (rval >= 0) {
                        an += rval;
                        continue;
                }
                switch (argv[an][1]) {
                case 'e':                               /* exposure */
                        check(2,"f");
                        expcomp = argv[++an];
                        break;
                case 't':                               /* threshold */
                        check(2,"f");
                        zeps = atof(argv[++an]);
                        break;
                case 'a':                               /* average */
                        check(2,NULL);
                        doavg = 1;
                        break;
                case 'B':                               /* blur views */
                        check(2,NULL);
                        doblur = 1;
                        break;
                case 'q':                               /* quick (no avg.) */
                        check(2,NULL);
                        doavg = 0;
                        break;
                case 'n':                               /* dist. normalized? */
                        check(2,NULL);
                        normdist = !normdist;
                        break;
                case 'f':                               /* fill type */
                        switch (argv[an][2]) {
                        case '0':                               /* none */
                                check(3,NULL);
                                fillo = 0;
                                break;
                        case 'f':                               /* foreground */
                                check(3,NULL);
                                fillo = F_FORE;
                                break;
                        case 'b':                               /* background */
                                check(3,NULL);
                                fillo = F_BACK;
                                break;
                        case 'a':                               /* all */
                                check(3,NULL);
                                fillo = F_FORE|F_BACK;
                                break;
                        case 's':                               /* sample */
                                check(3,"i");
                                fillsamp = atoi(argv[++an]);
                                break;
                        case 'c':                               /* color */
                                check(3,"fff");
                                fillfunc = backfill;
                                setcolor(backcolor, atof(argv[an+1]),
                                        atof(argv[an+2]), atof(argv[an+3]));
                                setcolr(backcolr, colval(backcolor,RED),
                                                colval(backcolor,GRN),
                                                colval(backcolor,BLU));
                                an += 3;
                                break;
                        case 'z':                               /* z value */
                                check(3,"f");
                                fillfunc = backfill;
                                backz = atof(argv[++an]);
                                break;
                        case 'r':                               /* rtrace */
                                check(3,"s");
                                fillfunc = rcalfill;
                                calstart(RTCOM, argv[++an]);
                                break;
                        default:
                                goto badopt;
                        }
                        break;
                case 'z':                               /* z file */
                        check(2,"s");
                        zfile = argv[++an];
                        break;
                case 'x':                               /* x resolution */
                        check(2,"i");
                        hresolu = atoi(argv[++an]);
                        break;
                case 'y':                               /* y resolution */
                        check(2,"i");
                        vresolu = atoi(argv[++an]);
                        break;
                case 'p':                               /* pixel aspect */
                        if (argv[an][2] != 'a')
                                goto badopt;
                        check(3,"f");
                        pixaspect = atof(argv[++an]);
                        break;
                case 'v':                               /* view file */
                        if (argv[an][2] != 'f')
                                goto badopt;
                        check(3,"s");
                        gotvfile = viewfile(argv[++an], &ourview, 0, 0);
                        if (gotvfile < 0)
                                syserror(argv[an]);
                        else if (gotvfile == 0) {
                                fprintf(stderr, "%s: bad view file\n",
                                                argv[an]);
                                exit(1);
                        }
                        break;
                default:
                badopt:
                        fprintf(stderr, "%s: command line error at '%s'\n",
                                        progname, argv[an]);
                        goto userr;
                }
        }
                                                /* check arguments */
        if ((argc-an)%2)
                goto userr;
        if (fillsamp == 1)
                fillo &= ~F_BACK;
        if (doavg < 0)
                doavg = (argc-an) > 2;
        if (expcomp != NULL)
                if (expcomp[0] == '+' | expcomp[0] == '-') {
                        expadj = atof(expcomp) + (expcomp[0]=='+' ? .5 : -.5);
                        if (doavg | doblur)
                                rexpadj = pow(2.0, atof(expcomp));
                        else
                                rexpadj = pow(2.0, (double)expadj);
                } else {
                        if (!isflt(expcomp))
                                goto userr;
                        rexpadj = atof(expcomp);
                        expadj = log(rexpadj)/LOG2 + (rexpadj>1 ? .5 : -.5);
                        if (!(doavg | doblur))
                                rexpadj = pow(2.0, (double)expadj);
                }
                                                /* set view */
        if (nextview(doblur ? stdin : (FILE *)NULL) == EOF) {
                fprintf(stderr, "%s: no view on standard input!\n",
                                progname);
                exit(1);
        }
        normaspect(viewaspect(&ourview), &pixaspect, &hresolu, &vresolu);
                                                /* allocate frame */
        if (doavg) {
                ourspict = (COLOR *)bmalloc(hresolu*vresolu*sizeof(COLOR));
                ourweigh = (float *)bmalloc(hresolu*vresolu*sizeof(float));
                if (ourspict == NULL | ourweigh == NULL)
                        syserror(progname);
        } else {
                ourpict = (COLR *)bmalloc(hresolu*vresolu*sizeof(COLR));
                if (ourpict == NULL)
                        syserror(progname);
        }
        if (doblur) {
                ourbpict = (COLOR *)bmalloc(hresolu*vresolu*sizeof(COLOR));
                if (ourbpict == NULL)
                        syserror(progname);
        }
        ourzbuf = (float *)bmalloc(hresolu*vresolu*sizeof(float));
        if (ourzbuf == NULL)
                syserror(progname);
                                                        /* new header */
        newheader("RADIANCE", stdout);
                                                        /* run pictures */
        do {
                bzero((char *)ourzbuf, hresolu*vresolu*sizeof(float));
                for (i = an; i < argc; i += 2)
                        addpicture(argv[i], argv[i+1]);
                if (fillo&F_BACK)                       /* fill in spaces */
                        backpicture(fillfunc, fillsamp);
                else
                        fillpicture(fillfunc);
                                                        /* aft clipping */
                clipaft();
        } while (addblur() && nextview(stdin) != EOF);
                                                        /* close calculation */
        caldone();
                                                        /* add to header */
        printargs(argc, argv, stdout);
        compavgview();
        if (doblur | gotvfile) {
                fputs(VIEWSTR, stdout);
                fprintview(&avgview, stdout);
                putc('\n', stdout);
        }
        if (pixaspect < .99 | pixaspect > 1.01)
                fputaspect(pixaspect, stdout);
        if (ourexp > 0)
                ourexp *= rexpadj;
        else
                ourexp = rexpadj;
        if (ourexp < .995 | ourexp > 1.005)
                fputexpos(ourexp, stdout);
        if (strcmp(ourfmt, PICFMT))             /* print format if known */
                fputformat(ourfmt, stdout);
        putc('\n', stdout);
                                                        /* write picture */
        writepicture();
                                                        /* write z file */
        if (zfile != NULL)
                writedistance(zfile);

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


int
headline(s)                             /* process header string */
char    *s;
{
        char    fmt[32];

        if (isheadid(s))
                return(0);
        if (formatval(fmt, s)) {
                if (globmatch(ourfmt, fmt)) {
                        wrongformat = 0;
                        strcpy(ourfmt, fmt);
                } else
                        wrongformat = 1;
                return(0);
        }
        if (nvavg < 2) {
                putc('\t', stdout);
                fputs(s, stdout);
        }
        if (isexpos(s)) {
                theirexp *= exposval(s);
                return(0);
        }
        if (isview(s) && sscanview(&theirview, s) > 0)
                gotview++;
        return(0);
}


nextview(fp)                            /* get and set next view */
FILE    *fp;
{
        char    linebuf[256];
        char    *err;
        register int    i;

        if (fp != NULL) {
                do                      /* get new view */
                        if (fgets(linebuf, sizeof(linebuf), fp) == NULL)
                                return(EOF);
                while (!isview(linebuf) || !sscanview(&ourview, linebuf));
        }
                                        /* set new view */
        if ((err = setview(&ourview)) != NULL) {
                fprintf(stderr, "%s: %s\n", progname, err);
                exit(1);
        }
        if (!nvavg) {                   /* first view */
                copystruct(&avgview, &ourview);
                return(nvavg++);
        }
                                        /* add to average view */
        for (i = 0; i < 3; i++) {
                avgview.vp[i] += ourview.vp[i];
                avgview.vdir[i] += ourview.vdir[i];
                avgview.vup[i] += ourview.vup[i];
        }
        avgview.horiz += ourview.horiz;
        avgview.vert += ourview.vert;
        avgview.hoff += ourview.hoff;
        avgview.voff += ourview.voff;
        avgview.vfore += ourview.vfore;
        avgview.vaft += ourview.vaft;
        return(nvavg++);
}


compavgview()                           /* compute average view */
{
        register int    i;
        double  f;

        if (nvavg < 2)
                return;
        f = 1.0/nvavg;
        for (i = 0; i < 3; i++) {
                avgview.vp[i] *= f;
                avgview.vdir[i] *= f;
                avgview.vup[i] *= f;
        }
        avgview.horiz *= f;
        avgview.vert *= f;
        avgview.hoff *= f;
        avgview.voff *= f;
        avgview.vfore *= f;
        avgview.vaft *= f;
        if (setview(&avgview) != NULL)          /* in case of emergency... */
                copystruct(&avgview, &ourview);
        pixaspect = viewaspect(&avgview) * hresolu / vresolu;
}


addpicture(pfile, zspec)                /* add picture to output */
char    *pfile, *zspec;
{
        FILE    *pfp;
        int     zfd;
        char    *err;
        COLR    *scanin;
        float   *zin;
        struct position *plast;
        struct bound    *xlim, ylim;
        int     y;
                                        /* open picture file */
        if ((pfp = fopen(pfile, "r")) == NULL)
                syserror(pfile);
                                        /* get header with exposure and view */
        theirexp = 1.0;
        copystruct(&theirview, &stdview);
        gotview = 0;
        if (nvavg < 2)
                printf("%s:\n", pfile);
        getheader(pfp, headline, NULL);
        if (wrongformat || !gotview || !fgetsresolu(&tresolu, pfp)) {
                fprintf(stderr, "%s: picture format 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 */
        hasmatrix = pixform(theirs2ours, &theirview, &ourview);
                                        /* get z specification or file */
        zin = (float *)malloc(scanlen(&tresolu)*sizeof(float));
        if (zin == NULL)
                syserror(progname);
        if ((zfd = open(zspec, O_RDONLY)) == -1) {
                double  zvalue;
                register int    x;
                if (!isflt(zspec) || (zvalue = atof(zspec)) <= 0.0)
                        syserror(zspec);
                for (x = scanlen(&tresolu); x-- > 0; )
                        zin[x] = zvalue;
        }
                                        /* compute transferrable perimeter */
        xlim = (struct bound *)malloc(numscans(&tresolu)*sizeof(struct bound));
        if (xlim == NULL)
                syserror(progname);
        if (!getperim(xlim, &ylim, zin, zfd)) { /* overlapping area? */
                free((char *)zin);
                free((char *)xlim);
                if (zfd != -1)
                        close(zfd);
                fclose(pfp);
                return;
        }
                                        /* allocate scanlines */
        scanin = (COLR *)malloc(scanlen(&tresolu)*sizeof(COLR));
        plast = (struct position *)calloc(scanlen(&tresolu),
                        sizeof(struct position));
        if (scanin == NULL | plast == NULL)
                syserror(progname);
                                        /* skip to starting point */
        for (y = 0; y < ylim.min; y++)
                if (freadcolrs(scanin, scanlen(&tresolu), pfp) < 0) {
                        fprintf(stderr, "%s: read error\n", pfile);
                        exit(1);
                }
        if (zfd != -1 && lseek(zfd,
                        (long)ylim.min*scanlen(&tresolu)*sizeof(float), 0) < 0)
                syserror(zspec);
                                        /* load image */
        for (y = ylim.min; y <= ylim.max; y++) {
                if (freadcolrs(scanin, scanlen(&tresolu), pfp) < 0) {
                        fprintf(stderr, "%s: read error\n", pfile);
                        exit(1);
                }
                if (zfd != -1 && read(zfd, (char *)zin,
                                scanlen(&tresolu)*sizeof(float))
                                < scanlen(&tresolu)*sizeof(float))
                        syserror(zspec);
                addscanline(xlim+y, y, scanin, zin, plast);
        }
                                        /* clean up */
        free((char *)xlim);
        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 MAT4   xfmat;
register VIEW   *vw1, *vw2;
{
        double  m4t[4][4];

        if (vw1->type != VT_PER & vw1->type != VT_PAR)
                return(0);
        if (vw2->type != VT_PER & vw2->type != VT_PAR)
                return(0);
        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);
        return(1);
}


addscanline(xl, y, pline, zline, lasty) /* add scanline to output */
struct bound    *xl;
int     y;
COLR    *pline;
float   *zline;
struct position *lasty;         /* input/output */
{
        FVECT   pos;
        struct position lastx, newpos;
        double  wt;
        register int    x;

        lastx.z = 0;
        for (x = xl->max; x >= xl->min; x--) {
                pix2loc(pos, &tresolu, x, y);
                pos[2] = zline[x];
                if ((wt = movepixel(pos)) <= FTINY) {
                        lasty[x].z = lastx.z = 0;       /* mark invalid */
                        continue;
                }
                                        /* add pixel to our image */
                newpos.x = pos[0] * hresolu;
                newpos.y = pos[1] * vresolu;
                newpos.z = zline[x];
                addpixel(&newpos, &lastx, &lasty[x], pline[x], wt, pos[2]);
                lasty[x].x = lastx.x = newpos.x;
                lasty[x].y = lastx.y = newpos.y;
                lasty[x].z = lastx.z = newpos.z;
        }
}


addpixel(p0, p1, p2, pix, w, z)         /* fill in pixel parallelogram */
struct position *p0, *p1, *p2;
COLR    pix;
double  w;
double  z;
{
        double  zt = 2.*zeps*p0->z;             /* threshold */
        COLOR   pval;                           /* converted+weighted pixel */
        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 (fillo&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 if (l1 < 1)
                        l1 = 1;
        } else {
                l1 = s1x = s1y = 1;
                p1isy = -1;
        }
                                        /* compute vector p0p2 */
        if (fillo&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);
                }
                if (l2 < 1)
                        l2 = 1;
        } else
                l2 = s2x = s2y = 1;
                                        /* fill the parallelogram */
        if (averaging) {
                colr_color(pval, pix);
                scalecolor(pval, w);
        }
        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;
                        if (x < 0 | x >= hresolu)
                                continue;
                        y = y1 + c2*s2y/l2;
                        if (y < 0 | y >= vresolu)
                                continue;
                        if (averaging) {
                                if (zscan(y)[x] <= 0 || zscan(y)[x]-z
                                                > zeps*zscan(y)[x]) {
                                        copycolor(sscan(y)[x], pval);
                                        wscan(y)[x] = w;
                                        zscan(y)[x] = z;
                                } else if (z-zscan(y)[x] <= zeps*zscan(y)[x]) {
                                        addcolor(sscan(y)[x], pval);
                                        wscan(y)[x] += w;
                                }
                        } else if (zscan(y)[x] <= 0 || zscan(y)[x]-z
                                                > zeps*zscan(y)[x]) {
                                copycolr(pscan(y)[x], pix);
                                zscan(y)[x] = z;
                        }
                }
        }
}


double
movepixel(pos)                          /* reposition image point */
register FVECT  pos;
{
        FVECT   pt, tdir, odir;
        double  d;
        
        if (pos[2] <= 0)                /* empty pixel */
                return(0);
        if (usematrix) {
                pos[0] += theirview.hoff - .5;
                pos[1] += theirview.voff - .5;
                if (normdist & theirview.type == VT_PER)
                        d = sqrt(1. + pos[0]*pos[0]*theirview.hn2
                                        + pos[1]*pos[1]*theirview.vn2);
                else
                        d = 1.;
                pos[2] += d*theirview.vfore;
                if (theirview.type == VT_PER) {
                        pos[2] /= d;
                        pos[0] *= pos[2];
                        pos[1] *= pos[2];
                }
                multp3(pos, pos, theirs2ours);
                if (pos[2] <= ourview.vfore)
                        return(0);
                if (ourview.type == VT_PER) {
                        pos[0] /= pos[2];
                        pos[1] /= pos[2];
                }
                pos[0] += .5 - ourview.hoff;
                pos[1] += .5 - ourview.voff;
                pos[2] -= ourview.vfore;
        } else {
                if (viewray(pt, tdir, &theirview, pos[0], pos[1]) < -FTINY)
                        return(0);
                if (!normdist & theirview.type == VT_PER)       /* adjust */
                        pos[2] *= sqrt(1. + pos[0]*pos[0]*theirview.hn2
                                        + pos[1]*pos[1]*theirview.vn2);
                pt[0] += tdir[0]*pos[2];
                pt[1] += tdir[1]*pos[2];
                pt[2] += tdir[2]*pos[2];
                viewloc(pos, &ourview, pt);
                if (pos[2] <= 0)
                        return(0);
        }
        if (pos[0] < 0 | pos[0] >= 1-FTINY | pos[1] < 0 | pos[1] >= 1-FTINY)
                return(0);
        if (!averaging)
                return(1);
                                                /* compute pixel weight */
        if (ourview.type == VT_PAR) {
                d = DOT(ourview.vdir,tdir);
                d = 1. - d*d;
        } else {
                VSUB(odir, pt, ourview.vp);
                d = DOT(odir,tdir);
                d = 1. - d*d/DOT(odir,odir);
        }
        if (d <= 1./MAXWT/MAXWT)
                return(MAXWT);          /* clip to maximum weight */
        return(1./sqrt(d));
}


getperim(xl, yl, zline, zfd)            /* compute overlapping image area */
register struct bound   *xl;
struct bound    *yl;
float   *zline;
int     zfd;
{
        int     step;
        FVECT   pos;
        register int    x, y;
                                                /* set up step size */
        if (scanlen(&tresolu) < numscans(&tresolu))
                step = scanlen(&tresolu)/NSTEPS;
        else
                step = numscans(&tresolu)/NSTEPS;
        if (step < MINSTEP) {                   /* not worth cropping? */
                yl->min = 0;
                yl->max = numscans(&tresolu) - 1;
                x = scanlen(&tresolu) - 1;
                for (y = numscans(&tresolu); y--; ) {
                        xl[y].min = 0;
                        xl[y].max = x;
                }
                return(1);
        }
        yl->min = 32000; yl->max = 0;           /* search for points on image */
        for (y = step - 1; y < numscans(&tresolu); y += step) {
                if (zfd != -1) {
                        if (lseek(zfd, (long)y*scanlen(&tresolu)*sizeof(float),
                                        0) < 0)
                                syserror("lseek");
                        if (read(zfd, (char *)zline,
                                        scanlen(&tresolu)*sizeof(float))
                                        < scanlen(&tresolu)*sizeof(float))
                                syserror("read");
                }
                xl[y].min = 32000; xl[y].max = 0;               /* x max */
                for (x = scanlen(&tresolu); (x -= step) > 0; ) {
                        pix2loc(pos, &tresolu, x, y);
                        pos[2] = zline[x];
                        if (movepixel(pos) > FTINY) {
                                xl[y].max = x + step - 1;
                                xl[y].min = x - step + 1;       /* x min */
                                if (xl[y].min < 0)
                                        xl[y].min = 0;
                                for (x = step - 1; x < xl[y].max; x += step) {
                                        pix2loc(pos, &tresolu, x, y);
                                        pos[2] = zline[x];
                                        if (movepixel(pos) > FTINY) {
                                                xl[y].min = x - step + 1;
                                                break;
                                        }
                                }
                                if (y < yl->min)                /* y limits */
                                        yl->min = y - step + 1;
                                yl->max = y + step - 1;
                                break;
                        }
                }
                                                        /* fill in between */
                if (y < step) {
                        xl[y-1].min = xl[y].min;
                        xl[y-1].max = xl[y].max;
                } else {
                        if (xl[y].min < xl[y-step].min)
                                xl[y-1].min = xl[y].min;
                        else
                                xl[y-1].min = xl[y-step].min;
                        if (xl[y].max > xl[y-step].max)
                                xl[y-1].max = xl[y].max;
                        else
                                xl[y-1].max = xl[y-step].max;
                }
                for (x = 2; x < step; x++)
                        copystruct(xl+y-x, xl+y-1);
        }
        if (yl->max >= numscans(&tresolu))
                yl->max = numscans(&tresolu) - 1;
        y -= step;
        for (x = numscans(&tresolu) - 1; x > y; x--)    /* fill bottom rows */
                copystruct(xl+x, xl+y);
        return(yl->max >= yl->min);
}


backpicture(fill, samp)                 /* background fill algorithm */
int     (*fill)();
int     samp;
{
        int     *yback, xback;
        int     y;
        register int    x, i;
                                                        /* get back buffer */
        yback = (int *)malloc(hresolu*sizeof(int));
        if (yback == NULL)
                syserror(progname);
        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;
                                }
                                /*
                                 * If we have no background for this pixel,
                                 * use the given fill function.
                                 */
                                if (xback < 0 && yback[x] < 0)
                                        goto fillit;
                                /*
                                 * Compare, and use the background that is
                                 * farther, unless one of them is next to us.
                                 * If the background is too distant, call
                                 * the fill function.
                                 */
                                if ( yback[x] < 0
                                        || (xback >= 0 && ABS(x-xback) <= 1)
                                        || ( ABS(y-yback[x]) > 1
                                                && zscan(yback[x])[x]
                                                < zscan(y)[xback] ) ) {
                                        if (samp > 0 && ABS(x-xback) >= samp)
                                                goto fillit;
                                        if (averaging) {
                                                copycolor(sscan(y)[x],
                                                        sscan(y)[xback]);
                                                wscan(y)[x] = wscan(y)[xback];
                                        } else
                                                copycolr(pscan(y)[x],
                                                        pscan(y)[xback]);
                                        zscan(y)[x] = zscan(y)[xback];
                                } else {
                                        if (samp > 0 && ABS(y-yback[x]) > samp)
                                                goto fillit;
                                        if (averaging) {
                                                copycolor(sscan(y)[x],
                                                        sscan(yback[x])[x]);
                                                wscan(y)[x] =
                                                        wscan(yback[x])[x];
                                        } else
                                                copycolr(pscan(y)[x],
                                                        pscan(yback[x])[x]);
                                        zscan(y)[x] = zscan(yback[x])[x];
                                }
                                continue;
                        fillit:
                                (*fill)(x,y);
                                if (fill == rcalfill) {         /* use it */
                                        clearqueue();
                                        xback = x;
                                        yback[x] = y;
                                }
                        } else {                                /* full pixel */
                                yback[x] = -2;
                                xback = -2;
                        }
        }
        free((char *)yback);
}


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

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


clipaft()                       /* perform aft clipping as indicated */
{
        register int    x, y;
        int     adjtest = ourview.type == VT_PER & zisnorm;
        double  tstdist;
        double  yzn2, vx;

        if (ourview.vaft <= FTINY)
                return(0);
        tstdist = ourview.vaft - ourview.vfore;
        for (y = 0; y < vresolu; y++) {
                if (adjtest) {                          /* adjust test */
                        yzn2 = (y+.5)/vresolu + ourview.voff - .5;
                        yzn2 = 1. + yzn2*yzn2*ourview.vn2;
                        tstdist = (ourview.vaft - ourview.vfore)*sqrt(yzn2);
                }
                for (x = 0; x < hresolu; x++)
                        if (zscan(y)[x] > tstdist) {
                                if (adjtest) {
                                        vx = (x+.5)/hresolu + ourview.hoff - .5;
                                        if (zscan(y)[x] <= (ourview.vaft -
                                                        ourview.vfore) *
                                                sqrt(vx*vx*ourview.hn2 + yzn2))
                                                continue;
                                }
                                if (averaging)
                                        bzero(sscan(y)[x], sizeof(COLOR));
                                else
                                        bzero(pscan(y)[x], sizeof(COLR));
                                zscan(y)[x] = 0.0;
                        }
        }
        return(1);
}


addblur()                               /* add to blurred picture */
{
        COLOR   cval;
        double  d;
        register int    i;

        if (!blurring)
                return(0);
        i = hresolu*vresolu;
        if (nvavg < 2)
                if (averaging)
                        while (i--) {
                                copycolor(ourbpict[i], ourspict[i]);
                                d = 1.0/ourweigh[i];
                                scalecolor(ourbpict[i], d);
                        }
                else
                        while (i--)
                                colr_color(ourbpict[i], ourpict[i]);
        else
                if (averaging)
                        while (i--) {
                                copycolor(cval, ourspict[i]);
                                d = 1.0/ourweigh[i];
                                scalecolor(cval, d);
                                addcolor(ourbpict[i], cval);
                        }
                else
                        while (i--) {
                                colr_color(cval, ourpict[i]);
                                addcolor(ourbpict[i], cval);
                        }
                                /* print view */
        printf("VIEW%d:", nvavg);
        fprintview(&ourview, stdout);
        putchar('\n');
        return(1);
}


writepicture()                          /* write out picture (alters buffer) */
{
        int     y;
        register int    x;
        double  d;

        fprtresolu(hresolu, vresolu, stdout);
        for (y = vresolu-1; y >= 0; y--)
                if (blurring) {
                        for (x = 0; x < hresolu; x++) { /* compute avg. */
                                d = rexpadj/nvavg;
                                scalecolor(bscan(y)[x], d);
                        }
                        if (fwritescan(bscan(y), hresolu, stdout) < 0)
                                syserror(progname);
                } else if (averaging) {
                        for (x = 0; x < hresolu; x++) { /* average pixels */
                                d = rexpadj/wscan(y)[x];
                                scalecolor(sscan(y)[x], d);
                        }
                        if (fwritescan(sscan(y), hresolu, stdout) < 0)
                                syserror(progname);
                } else {
                        if (expadj)
                                shiftcolrs(pscan(y), hresolu, expadj);
                        if (fwritecolrs(pscan(y), hresolu, stdout) < 0)
                                syserror(progname);
                }
}


writedistance(fname)                    /* write out z file (alters buffer) */
char    *fname;
{
        int     donorm = normdist & !zisnorm ? 1 :
                        ourview.type == VT_PER & !normdist & zisnorm ? -1 : 0;
        int     fd;
        int     y;

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


backfill(x, y)                          /* fill pixel with background */
int     x, y;
{
        if (averaging) {
                copycolor(sscan(y)[x], backcolor);
                wscan(y)[x] = 1;
        } else
                copycolr(pscan(y)[x], backcolr);
        zscan(y)[x] = backz;
}


calstart(prog, args)                    /* start fill calculation */
char    *prog, *args;
{
        char    combuf[512];
        char    *argv[64];
        int     rval;
        register char   **wp, *cp;

        if (childpid != -1) {
                fprintf(stderr, "%s: too many calculations\n", progname);
                exit(1);
        }
        strcpy(combuf, prog);
        strcat(combuf, args);
        cp = combuf;
        wp = argv;
        for ( ; ; ) {
                while (isspace(*cp))    /* nullify spaces */
                        *cp++ = '\0';
                if (!*cp)               /* all done? */
                        break;
                *wp++ = cp;             /* add argument to list */
                while (*++cp && !isspace(*cp))
                        ;
        }
        *wp = NULL;
                                                /* start process */
        if ((rval = open_process(PDesc, argv)) < 0)
                syserror(progname);
        if (rval == 0) {
                fprintf(stderr, "%s: command not found\n", argv[0]);
                exit(1);
        }
        packsiz = rval/(6*sizeof(float)) - 1;
        if (packsiz > PACKSIZ)
                packsiz = PACKSIZ;
        queuesiz = 0;
}


caldone()                               /* done with calculation */
{
        if (childpid == -1)
                return;
        clearqueue();
        close_process(PDesc);
        childpid = -1;
}


rcalfill(x, y)                          /* fill with ray-calculated pixel */
int     x, y;
{
        if (queuesiz >= packsiz)        /* flush queue if needed */
                clearqueue();
                                        /* add position to queue */
        queue[queuesiz][0] = x;
        queue[queuesiz][1] = y;
        queuesiz++;
}


clearqueue()                            /* process queue */
{
        FVECT   orig, dir;
        float   fbuf[6*(PACKSIZ+1)];
        register float  *fbp;
        register int    i;
        double  vx, vy;

        if (queuesiz == 0)
                return;
        fbp = fbuf;
        for (i = 0; i < queuesiz; i++) {
                viewray(orig, dir, &ourview,
                                (queue[i][0]+.5)/hresolu,
                                (queue[i][1]+.5)/vresolu);
                *fbp++ = orig[0]; *fbp++ = orig[1]; *fbp++ = orig[2];
                *fbp++ = dir[0]; *fbp++ = dir[1]; *fbp++ = dir[2];
        }
                                        /* mark end and get results */
        bzero((char *)fbp, 6*sizeof(float));
        if (process(PDesc, fbuf, fbuf, 4*sizeof(float)*(queuesiz+1),
                        6*sizeof(float)*(queuesiz+1)) !=
                        4*sizeof(float)*(queuesiz+1)) {
                fprintf(stderr, "%s: error reading from rtrace process\n",
                                progname);
                exit(1);
        }
        fbp = fbuf;
        for (i = 0; i < queuesiz; i++) {
                if (ourexp > 0 && ourexp != 1.0) {
                        fbp[0] *= ourexp;
                        fbp[1] *= ourexp;
                        fbp[2] *= ourexp;
                }
                if (averaging) {
                        setcolor(sscan(queue[i][1])[queue[i][0]],
                                        fbp[0], fbp[1], fbp[2]);
                        wscan(queue[i][1])[queue[i][0]] = 1;
                } else
                        setcolr(pscan(queue[i][1])[queue[i][0]],
                                        fbp[0], fbp[1], fbp[2]);
                if (zisnorm)
                        zscan(queue[i][1])[queue[i][0]] = fbp[3];
                else {
                        vx = (queue[i][0]+.5)/hresolu + ourview.hoff - .5;
                        vy = (queue[i][1]+.5)/vresolu + ourview.voff - .5;
                        zscan(queue[i][1])[queue[i][0]] = fbp[3] / sqrt(1. +
                                        vx*vx*ourview.hn2 + vy*vy*ourview.vn2);
                }
                fbp += 4;
        }
        queuesiz = 0;
}


syserror(s)                     /* report error and exit */
char    *s;
{
        perror(s);
        exit(1);
}
Revision:	2.32
Committed:	Fri Jul 16 16:11:31 1999 UTC (24 years, 9 months ago) by gwlarson
Content type:	text/plain
Branch:	MAIN
Changes since 2.31:	+13 -11 lines
Log Message:	improved pixel weighting computation