src/rt/rpict.c

#ifndef lint
static const char RCSid[] = "$Id: rpict.c,v 1.2 2014/11/25 17:47:11 taschreg Exp taschreg $";
#endif
/*
 *  rpict.c - routines and variables for picture generation.
 */

#include "copyright.h"

#include  <sys/types.h>

#include  "platform.h"
#ifdef NON_POSIX
 #ifdef MINGW
  #include  <sys/time.h>
 #endif
#else
 #ifdef BSD
  #include  <sys/time.h>
  #include  <sys/resource.h>
 #else
  #include  <sys/times.h>
  #include  <unistd.h>
 #endif
#endif

#include  <time.h>
#include  <signal.h>

#include  "ray.h"
#include  "paths.h"
#include  "ambient.h"
#include  "view.h"
#include  "random.h"
#include  "paths.h"
#include  "hilbert.h"
#include  "pmapbias.h"
#include  "pmapdiag.h"

#define  RFTEMPLATE     "rfXXXXXX"

#ifndef SIGCONT
#ifdef SIGIO     /* XXX can we live without this? */
#define SIGCONT         SIGIO
#endif
#endif

CUBE  thescene;                         /* our scene */
OBJECT  nsceneobjs;                     /* number of objects in our scene */

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

void  (*addobjnotify[])() = {ambnotify, NULL};

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

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

double  mblur = 0.;                     /* motion blur parameter */

double  dblur = 0.;                     /* depth-of-field blur parameter */

void  (*trace)() = NULL;                /* trace call */

int  do_irrad = 0;                      /* compute irradiance? */

int  rand_samp = 0;                     /* pure Monte Carlo sampling? */

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

COLOR  cextinction = BLKCOLOR;          /* global extinction coefficient */
COLOR  salbedo = BLKCOLOR;              /* global scattering albedo */
double  seccg = 0.;                     /* global scattering eccentricity */
double  ssampdist = 0.;                 /* scatter sampling distance */

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

int  backvis = 1;                       /* back face visibility */

int  maxdepth = 7;                      /* maximum recursion depth */
double  minweight = 1e-3;               /* minimum ray weight */

char  *ambfile = NULL;                  /* ambient file name */
COLOR  ambval = BLKCOLOR;               /* ambient value */
int  ambvwt = 0;                        /* initial weight for ambient value */
double  ambacc = 0.2;                   /* ambient accuracy */
int  ambres = 64;                       /* ambient resolution */
int  ambdiv = 512;                      /* ambient divisions */
int  ambssamp = 128;                    /* ambient super-samples */
int  ambounce = 0;                      /* ambient bounces */
char  *amblist[AMBLLEN];                /* ambient include/exclude list */
int  ambincl = -1;                      /* include == 1, exclude == 0 */

int  ralrm = 0;                         /* seconds between reports */

double  pctdone = 0.0;                  /* percentage done */
time_t  tlastrept = 0L;                 /* time at last report */
time_t  tstart;                         /* starting time */

#define  MAXDIV         16              /* maximum sample size */

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

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

static VIEW     lastview;               /* the previous view input */

static void report(int);
static int nextview(FILE *fp);
static void render(char *zfile, char *oldfile);
static void fillscanline(COLOR *scanline, float *zline, char *sd, int xres,
                int y, int xstep);
static void fillscanbar(COLOR *scanbar[], float *zbar[], int xres,
                int y, int ysize);
static int fillsample(COLOR *colline, float *zline, int x, int y,
                int xlen, int ylen, int b);
static double pixvalue(COLOR  col, int  x, int  y);
static int salvage(char  *oldfile);
static int pixnumber(int  x, int  y, int  xres, int  yres);


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


void
quit(code)                      /* quit program */
int  code;
{
        if (code)                       /* report status */
                report(0);
#ifndef NON_POSIX
        headclean();                    /* delete header file */
        pfclean();                      /* clean up persist files */
#endif
        exit(code);
}


#ifndef NON_POSIX
static void
report(int dummy)               /* report progress */
{
        char                    bcStat [128];
        double          u, s;
#ifdef BSD
        struct rusage   rubuf;
#else
        double          period = 1.0 / 60.0;
        struct tms      tbuf;
#endif

        tlastrept = time((time_t *)NULL);
#ifdef BSD
        getrusage(RUSAGE_SELF, &rubuf);
        u = rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec*1e-6;
        s = rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec*1e-6;
        getrusage(RUSAGE_CHILDREN, &rubuf);
        u += rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec*1e-6;
        s += rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec*1e-6;
#else
        times(&tbuf);
#ifdef _SC_CLK_TCK
        period = 1.0 / sysconf(_SC_CLK_TCK);
#endif
        u = ( tbuf.tms_utime + tbuf.tms_cutime ) * period;
        s = ( tbuf.tms_stime + tbuf.tms_cstime ) * period;
#endif

        /* PMAP: Get photon map bias compensation statistics */
        pmapBiasCompReport(bcStat);
        
        sprintf(errmsg,
                        "%lu rays, %s %4.2f%% after %.3fu %.3fs %.3fr hours on %s (PID %d)\n",
                        nrays, bcStat, pctdone, u*(1./3600.), s*(1./3600.),
                        (tlastrept-tstart)*(1./3600.), myhostname(), getpid());
        eputs(errmsg);
#ifdef SIGCONT
        signal(SIGCONT, report);
#endif
}
#else
static void
report(int dummy)               /* report progress */
{
        char    bcStat [128];
        
        tlastrept = time((time_t *)NULL);

        /* PMAP: Get photon map bias compensation statistics */
        pmapBiasCompReport(bcStat);
        
        sprintf(errmsg, "%lu rays, %s %4.2f%% after %5.4f hours\n",
                        nrays, bcStat, pctdone, (tlastrept-tstart)/3600.0);
        eputs(errmsg);
}
#endif


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


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

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


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


static void
fillscanline(   /* fill scan at y */
        COLOR   *scanline,
        float   *zline,
        char  *sd,
        int  xres,
        int  y,
        int  xstep
)
{
        static int  nc = 0;             /* number of calls */
        int  bl = xstep, b = xstep;
        double  z;
        int  i;

        z = pixvalue(scanline[0], 0, y);
        if (zline) zline[0] = z;
                                /* zig-zag start for quincunx pattern */
        for (i = ++nc & 1 ? xstep : xstep/2; i < xres-1+xstep; i += xstep) {
                if (i >= xres) {
                        xstep += xres-1-i;
                        i = xres-1;
                }
                z = pixvalue(scanline[i], i, y);
                if (zline) zline[i] = z;
                if (sd) b = sd[0] > sd[1] ? sd[0] : sd[1];
                if (i <= xstep)
                        b = fillsample(scanline, zline, 0, y, i, 0, b/2);
                else
                        b = fillsample(scanline+i-xstep,
                                        zline ? zline+i-xstep : (float *)NULL,
                                        i-xstep, y, xstep, 0, b/2);
                if (sd) *sd++ = nc & 1 ? bl : b;
                bl = b;
        }
        if (sd && nc & 1) *sd = bl;
}


static void
fillscanbar(    /* fill interior */
        COLOR   *scanbar[],
        float   *zbar[],
        int  xres,
        int  y,
        int  ysize
)
{
        COLOR  vline[MAXDIV+1];
        float  zline[MAXDIV+1];
        int  b = ysize;
        int  i, j;

        for (i = 0; i < xres; i++) {
                copycolor(vline[0], scanbar[0][i]);
                copycolor(vline[ysize], scanbar[ysize][i]);
                if (zbar[0]) {
                        zline[0] = zbar[0][i];
                        zline[ysize] = zbar[ysize][i];
                }
                b = fillsample(vline, zbar[0] ? zline : (float *)NULL,
                                i, y, 0, ysize, b/2);

                for (j = 1; j < ysize; j++)
                        copycolor(scanbar[j][i], vline[j]);
                if (zbar[0])
                        for (j = 1; j < ysize; j++)
                                zbar[j][i] = zline[j];
        }
}


static int
fillsample( /* fill interior points */
        COLOR   *colline,
        float   *zline,
        int  x,
        int  y,
        int  xlen,
        int  ylen,
        int  b
)
{
        double  ratio;
        double  z;
        COLOR  ctmp;
        int  ncut;
        int  len;

        if (xlen > 0)                   /* x or y length is zero */
                len = xlen;
        else
                len = ylen;

        if (len <= 1)                   /* limit recursion */
                return(0);

        if (b > 0 ||
        (zline && 2.*fabs(zline[0]-zline[len]) > maxdiff*(zline[0]+zline[len]))
                        || bigdiff(colline[0], colline[len], maxdiff)) {

                z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1));
                if (zline) zline[len>>1] = z;
                ncut = 1;
        } else {                                        /* interpolate */
                copycolor(colline[len>>1], colline[len]);
                ratio = (double)(len>>1) / len;
                scalecolor(colline[len>>1], ratio);
                if (zline) zline[len>>1] = zline[len] * ratio;
                ratio = 1.0 - ratio;
                copycolor(ctmp, colline[0]);
                scalecolor(ctmp, ratio);
                addcolor(colline[len>>1], ctmp);
                if (zline) zline[len>>1] += zline[0] * ratio;
                ncut = 0;
        }
                                                        /* recurse */
        ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2);

        ncut += fillsample(colline+(len>>1),
                        zline ? zline+(len>>1) : (float *)NULL,
                        x+(xlen>>1), y+(ylen>>1),
                        xlen-(xlen>>1), ylen-(ylen>>1), b/2);

        return(ncut);
}


static double
pixvalue(               /* compute pixel value */
        COLOR  col,                     /* returned color */
        int  x,                 /* pixel position */
        int  y
)
{
        extern void  SDsquare2disk(double ds[2], double seedx, double seedy);
        RAY  thisray;
        FVECT   lorg, ldir;
        double  hpos, vpos, vdist, lmax;
        int     i;
                                                /* compute view ray */
        setcolor(col, 0.0, 0.0, 0.0);
        hpos = (x+pixjitter())/hres;
        vpos = (y+pixjitter())/vres;
        if ((thisray.rmax = viewray(thisray.rorg, thisray.rdir,
                                        &ourview, hpos, vpos)) < -FTINY)
                return(0.0);

        vdist = ourview.vdist;
                                                /* set pixel index */
        samplendx = pixnumber(x,y,hres,vres);
                                                /* optional motion blur */
        if (lastview.type && mblur > FTINY && (lmax = viewray(lorg, ldir,
                                        &lastview, hpos, vpos)) >= -FTINY) {
                double  d = mblur*(.5-urand(281+samplendx));

                thisray.rmax = (1.-d)*thisray.rmax + d*lmax;
                for (i = 3; i--; ) {
                        thisray.rorg[i] = (1.-d)*thisray.rorg[i] + d*lorg[i];
                        thisray.rdir[i] = (1.-d)*thisray.rdir[i] + d*ldir[i];
                }
                if (normalize(thisray.rdir) == 0.0)
                        return(0.0);
                vdist = (1.-d)*vdist + d*lastview.vdist;
        }
                                                /* optional depth-of-field */
        if (dblur > FTINY) {
                double  vc, df[2];
                                                /* random point on disk */
                SDsquare2disk(df, frandom(), frandom());
                df[0] *= .5*dblur;
                df[1] *= .5*dblur;
                if ((ourview.type == VT_PER) | (ourview.type == VT_PAR)) {
                        double  adj = 1.0;
                        if (ourview.type == VT_PER)
                                adj /= DOT(thisray.rdir, ourview.vdir);
                        df[0] /= sqrt(ourview.hn2);
                        df[1] /= sqrt(ourview.vn2);
                        for (i = 3; i--; ) {
                                vc = ourview.vp[i] + adj*vdist*thisray.rdir[i];
                                thisray.rorg[i] += df[0]*ourview.hvec[i] +
                                                        df[1]*ourview.vvec[i] ;
                                thisray.rdir[i] = vc - thisray.rorg[i];
                        }
                } else {                        /* non-standard view case */
                        double  dfd = PI/4.*dblur*(.5 - frandom());
                        if ((ourview.type != VT_ANG) & (ourview.type != VT_PLS)) {
                                if (ourview.type != VT_CYL)
                                        df[0] /= sqrt(ourview.hn2);
                                df[1] /= sqrt(ourview.vn2);
                        }
                        for (i = 3; i--; ) {
                                vc = ourview.vp[i] + vdist*thisray.rdir[i];
                                thisray.rorg[i] += df[0]*ourview.hvec[i] +
                                                        df[1]*ourview.vvec[i] +
                                                        dfd*ourview.vdir[i] ;
                                thisray.rdir[i] = vc - thisray.rorg[i];
                        }
                }
                if (normalize(thisray.rdir) == 0.0)
                        return(0.0);
        }

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

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

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

        return(thisray.rt);                     /* return distance */
}


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

        if (oldfile == NULL)
                goto gotzip;

        if ((fp = fopen(oldfile, "r")) == NULL) {
                sprintf(errmsg, "cannot open recover file \"%s\"", oldfile);
                error(WARNING, errmsg);
                goto gotzip;
        }
        SET_FILE_BINARY(fp);
                                /* discard header */
        getheader(fp, NULL, NULL);
                                /* get picture size */
        if (!fscnresolu(&x, &y, fp)) {
                sprintf(errmsg, "bad recover file \"%s\" - not removed",
                                oldfile);
                error(WARNING, errmsg);
                fclose(fp);
                goto gotzip;
        }

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

        scanline = (COLR *)malloc(hres*sizeof(COLR));
        if (scanline == NULL)
                error(SYSTEM, "out of memory in salvage");
        for (y = 0; y < vres; y++) {
                if (freadcolrs(scanline, hres, fp) < 0)
                        break;
                if (fwritecolrs(scanline, hres, stdout) < 0)
                        goto writerr;
        }
        if (fflush(stdout) == EOF)
                goto writerr;
        free((void *)scanline);
        fclose(fp);
        unlink(oldfile);
        return(y);
gotzip:
        if (fflush(stdout) == EOF)
                error(SYSTEM, "error writing picture header");
        return(0);
writerr:
        sprintf(errmsg, "write error during recovery of \"%s\"", oldfile);
        error(SYSTEM, errmsg);
        return -1; /* pro forma return */
}

static int
pixnumber(              /* compute pixel index (screen door) */
        int  x,
        int  y,
        int  xres,
        int  yres
)
{
        unsigned        nbits = 0;
        bitmask_t       coord[2];

        if (xres < yres) xres = yres;
        while (xres > 0) {
                xres >>= 1;
                ++nbits;
        }
        coord[0] = x; coord[1] = y;
        return ((int)hilbert_c2i(2, nbits, coord));
}
Revision:	2.89
Committed:	Tue Feb 24 19:39:27 2015 UTC (9 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.88:	+17 -6 lines
Log Message:	Initial check-in of photon map addition by Roland Schregle