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/* Copyright (c) 1991 Regents of the University of California */ | 
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 | 
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#ifndef lint | 
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static char SCCSid[] = "$SunId$ LBL"; | 
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#endif | 
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 | 
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/* | 
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 * Compute pixels for glare calculation | 
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 */ | 
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 | 
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#include "glare.h" | 
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#include <sys/param.h> | 
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                                        /* compute rtrace buffer size */ | 
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#ifndef PIPE_BUF | 
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#define PIPE_BUF        512             /* hyperconservative */ | 
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#endif | 
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#define MAXPIX          (PIPE_BUF/(6*sizeof(float)) - 1) | 
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 | 
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#ifndef BSD | 
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#define vfork           fork | 
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#endif | 
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 | 
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#define NSCANS          64              /* number of scanlines to buffer */ | 
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 | 
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int     rt_pid = -1;            /* process id for rtrace */ | 
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int     fd_tort, fd_fromrt;     /* pipe descriptors */ | 
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 | 
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FILE    *pictfp = NULL;         /* picture file pointer */ | 
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double  exposure;               /* picture exposure */ | 
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int     pxsiz, pysiz;           /* picture dimensions */ | 
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int     curpos;                 /* current scanline */ | 
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long    *scanpos;               /* scanline positions */ | 
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struct { | 
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        long    lused;          /* for LRU replacement */ | 
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        int     y;              /* scanline position */ | 
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        COLR    *sl;            /* scanline contents */ | 
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} scan[NSCANS];         /* buffered scanlines */ | 
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 | 
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static long     ncall = 0L;     /* number of calls to getpictscan */ | 
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static long     nread = 0L;     /* number of scanlines read */ | 
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 | 
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 | 
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COLR * | 
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getpictscan(y)                  /* get picture scanline */ | 
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int     y; | 
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{ | 
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        extern long     ftell(); | 
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        int     minused; | 
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        register int    i; | 
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                                        /* first check our buffers */ | 
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        ncall++; | 
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        minused = 0; | 
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        for (i = 0; i < NSCANS; i++) { | 
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                if (scan[i].y == y) { | 
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                        scan[i].lused = ncall; | 
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                        return(scan[i].sl); | 
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                } | 
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                if (scan[i].lused < scan[minused].lused) | 
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                        minused = i; | 
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        } | 
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                                        /* not there, read it in */ | 
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        if (scanpos[y] == -1) {                 /* need to search */ | 
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                while (curpos > y) { | 
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                        scanpos[curpos] = ftell(pictfp); | 
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                        if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0) | 
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                                goto readerr; | 
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                        curpos--; | 
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                } | 
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        } else if (fseek(pictfp, scanpos[y], 0) < 0) { | 
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                fprintf(stderr, "%s: picture seek error\n", progname); | 
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                exit(1); | 
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        } | 
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        if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0) | 
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                goto readerr; | 
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        nread++; | 
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        curpos = y-1; | 
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        scan[minused].lused = ncall; | 
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        scan[minused].y = y; | 
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        return(scan[minused].sl); | 
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readerr: | 
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        fprintf(stderr, "%s: picture read error\n", progname); | 
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        exit(1); | 
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} | 
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 | 
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 | 
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pict_stats()                    /* print out picture read statistics */ | 
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{ | 
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        static long     lastcall = 0L;  /* ncall at last report */ | 
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        static long     lastread = 0L;  /* nread at last report */ | 
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 | 
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        if (ncall == lastcall) | 
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                return; | 
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        fprintf(stderr, "%s: %ld scanlines read, %ld reused\n", | 
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                        progname, nread-lastread, | 
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                        (ncall-lastcall)-(nread-lastread)); | 
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        lastcall = ncall; | 
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        lastread = nread; | 
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} | 
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 | 
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 | 
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double | 
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pict_val(vd)                    /* find picture value for view direction */ | 
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FVECT   vd; | 
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{ | 
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        FVECT   pp; | 
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        double  vpx, vpy, vpz; | 
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        COLOR   res; | 
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 | 
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        if (pictfp == NULL) | 
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                return(-1.0); | 
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        pp[0] = pictview.vp[0] + vd[0]; | 
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        pp[1] = pictview.vp[1] + vd[1]; | 
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        pp[2] = pictview.vp[2] + vd[2]; | 
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        viewpixel(&vpx, &vpy, &vpz, &pictview, pp); | 
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        if (vpz <= FTINY || vpx < 0. || vpx >= 1. || vpy < 0. || vpy >= 1.) | 
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                return(-1.0); | 
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        colr_color(res, getpictscan((int)(vpy*pysiz))[(int)(vpx*pxsiz)]); | 
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        return(luminance(res)/exposure); | 
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} | 
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 | 
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 | 
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double | 
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getviewpix(vh, vv)              /* compute single view pixel */ | 
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int     vh, vv; | 
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{ | 
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        FVECT   dir; | 
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        float   rt_buf[6]; | 
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        double  res; | 
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 | 
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        if (compdir(dir, vh, vv) < 0) | 
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                return(-1.0); | 
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        if ((res = pict_val(dir)) >= 0.0) | 
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                return(res); | 
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        if (rt_pid == -1) | 
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                return(-1.0); | 
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        rt_buf[0] = ourview.vp[0]; | 
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        rt_buf[1] = ourview.vp[1]; | 
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        rt_buf[2] = ourview.vp[2]; | 
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        rt_buf[3] = dir[0]; | 
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        rt_buf[4] = dir[1]; | 
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        rt_buf[5] = dir[2]; | 
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        rt_compute(rt_buf, 1); | 
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        return(luminance(rt_buf)); | 
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} | 
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 | 
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 | 
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getviewspan(vv, vb)             /* compute a span of view pixels */ | 
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int     vv; | 
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float   *vb; | 
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{ | 
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        float   rt_buf[6*MAXPIX];       /* rtrace send/receive buffer */ | 
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        register int    n;              /* number of pixels in buffer */ | 
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        short   buf_vh[MAXPIX];         /* pixel positions */ | 
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        FVECT   dir; | 
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        register int    vh; | 
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 | 
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#ifdef DEBUG | 
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        if (verbose) | 
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                fprintf(stderr, "%s: computing view span at %d...\n", | 
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                                progname, vv); | 
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#endif | 
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        n = 0; | 
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        for (vh = -hsize; vh <= hsize; vh++) { | 
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                if (compdir(dir, vh, vv) < 0) { /* off viewable region */ | 
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                        vb[vh+hsize] = -1.0; | 
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                        continue; | 
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                } | 
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                if ((vb[vh+hsize] = pict_val(dir)) >= 0.0) | 
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                        continue; | 
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                if (rt_pid == -1)               /* missing information */ | 
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                        continue; | 
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                                                /* send to rtrace */ | 
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                if (n >= MAXPIX) {                      /* flush */ | 
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                        rt_compute(rt_buf, n); | 
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                        while (n-- > 0) | 
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                                vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n); | 
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                } | 
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                rt_buf[6*n] = ourview.vp[0]; | 
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                rt_buf[6*n+1] = ourview.vp[1]; | 
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                rt_buf[6*n+2] = ourview.vp[2]; | 
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                rt_buf[6*n+3] = dir[0]; | 
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                rt_buf[6*n+4] = dir[1]; | 
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                rt_buf[6*n+5] = dir[2]; | 
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                buf_vh[n++] = vh; | 
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        } | 
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#ifdef DEBUG | 
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        if (verbose) | 
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                pict_stats(); | 
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#endif | 
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        if (n > 0) {                            /* process pending buffer */ | 
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                rt_compute(rt_buf, n); | 
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                while (n-- > 0) | 
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                        vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n); | 
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        } | 
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} | 
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 | 
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 | 
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rt_compute(pb, np)              /* process buffer through rtrace */ | 
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float   *pb; | 
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int     np; | 
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{ | 
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        static float    nbuf[6] = {0.,0.,0.,0.,0.,0.}; | 
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 | 
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#ifdef DEBUG | 
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        if (verbose && np > 1) | 
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                fprintf(stderr, "%s: sending %d samples to rtrace...\n", | 
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                                progname, np); | 
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#endif | 
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        if (writebuf(fd_tort,(char *)pb,6*sizeof(float)*np) < 6*sizeof(float)*np | 
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                || writebuf(fd_tort,(char *)nbuf,sizeof(nbuf)) < sizeof(nbuf)) { | 
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                fprintf(stderr, "%s: error writing to rtrace process\n", | 
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                                progname); | 
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                exit(1); | 
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        } | 
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        if (readbuf(fd_fromrt, (char *)pb, 3*sizeof(float)*np) | 
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                        < 3*sizeof(float)*np) { | 
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                fprintf(stderr, "%s: error reading from rtrace process\n", | 
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                                progname); | 
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                exit(1); | 
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        } | 
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} | 
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 | 
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 | 
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getexpos(s)                     /* get exposure from header line */ | 
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char    *s; | 
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{ | 
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        if (isexpos(s)) | 
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                exposure *= exposval(s); | 
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} | 
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 | 
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 | 
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open_pict(fn)                   /* open picture file */ | 
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char    *fn; | 
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{ | 
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        register int    i; | 
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 | 
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        if ((pictfp = fopen(fn, "r")) == NULL) { | 
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                fprintf("%s: cannot open\n", fn); | 
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                exit(1); | 
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        } | 
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        exposure = 1.0; | 
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        getheader(pictfp, getexpos); | 
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        if (fgetresolu(&pxsiz, &pysiz, pictfp) != (YMAJOR|YDECR)) { | 
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                fprintf("%s: bad picture resolution\n", fn); | 
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                exit(1); | 
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        } | 
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        scanpos = (long *)malloc(pysiz*sizeof(long)); | 
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        if (scanpos == NULL) | 
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                memerr("scanline positions"); | 
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        for (i = 0; i < pysiz; i++) | 
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                scanpos[i] = -1L; | 
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        for (i = 0; i < NSCANS; i++) { | 
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                scan[i].lused = -1; | 
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                scan[i].y = -1; | 
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                scan[i].sl = (COLR *)malloc(pxsiz*sizeof(COLR)); | 
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                if (scan[i].sl == NULL) | 
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                        memerr("scanline buffers"); | 
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        } | 
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        curpos = pysiz-1; | 
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} | 
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 | 
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 | 
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close_pict()                    /* done with picture */ | 
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{ | 
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        register int    i; | 
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 | 
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        if (pictfp == NULL) | 
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                return; | 
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        fclose(pictfp); | 
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        free((char *)scanpos); | 
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        for (i = 0; i < NSCANS; i++) | 
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                free((char *)scan[i].sl); | 
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        pictfp = NULL; | 
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} | 
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 | 
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 | 
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fork_rtrace(av)                 /* open pipe and start rtrace */ | 
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char    *av[]; | 
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{ | 
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        int     p0[2], p1[2]; | 
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 | 
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        if (pipe(p0) < 0 || pipe(p1) < 0) { | 
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                perror(progname); | 
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                exit(1); | 
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        } | 
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        if ((rt_pid = vfork()) == 0) {          /* if child */ | 
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                close(p0[1]); | 
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                close(p1[0]); | 
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                if (p0[0] != 0) {       /* connect p0 to stdin */ | 
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                        dup2(p0[0], 0); | 
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                        close(p0[0]); | 
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                } | 
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                if (p1[1] != 0) {       /* connect p1 to stdout */ | 
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                        dup2(p1[1], 1); | 
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                        close(p1[1]); | 
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                } | 
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                execvp(av[0], av); | 
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                perror(av[0]); | 
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                _exit(127); | 
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        } | 
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        if (rt_pid == -1) { | 
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                perror(progname); | 
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                exit(1); | 
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        } | 
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        close(p0[0]); | 
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        close(p1[1]); | 
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        fd_tort = p0[1]; | 
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        fd_fromrt = p1[0]; | 
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} | 
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 | 
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 | 
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done_rtrace()                   /* wait for rtrace to finish */ | 
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{ | 
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        int     pid, status; | 
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 | 
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        if (rt_pid == -1) | 
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                return; | 
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        close(fd_tort); | 
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        close(fd_fromrt); | 
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        while ((pid = wait(&status)) != -1 && pid != rt_pid) | 
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                ; | 
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        if (pid == rt_pid && status != 0) { | 
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                fprintf(stderr, "%s: bad status (%d) from rtrace\n", | 
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                                progname, status); | 
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                exit(1); | 
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        } | 
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        rt_pid = -1; | 
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} | 
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 | 
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 | 
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int | 
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readbuf(fd, bpos, siz) | 
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int     fd; | 
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char    *bpos; | 
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int     siz; | 
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{ | 
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        register int    cc, nrem = siz; | 
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 | 
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        while (nrem > 0 && (cc = read(fd, bpos, nrem)) > 0) { | 
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                bpos += cc; | 
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                nrem -= cc; | 
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        } | 
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        if (cc < 0) | 
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                return(cc); | 
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        return(siz-nrem); | 
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} | 
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 | 
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 | 
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int | 
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writebuf(fd, bpos, siz) | 
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char    *bpos; | 
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int     siz; | 
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{ | 
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        register int    cc, nrem = siz; | 
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 | 
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        while (nrem > 0 && (cc = write(fd, bpos, nrem)) > 0) { | 
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                bpos += cc; | 
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                nrem -= cc; | 
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        } | 
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        if (cc < 0) | 
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                return(cc); | 
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        return(siz-nrem); | 
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} |