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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 16 /* 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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|
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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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static long ncall = 0; |
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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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if (verbose) |
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fprintf(stderr, "%s: reading picture...\n", |
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progname); |
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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 (verbose) |
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fprintf(stderr, "%s: reading scanline %d...\n", progname, y); |
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if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0) |
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goto readerr; |
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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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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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int npix_tort; /* 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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register int i; |
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|
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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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npix_tort = 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 (npix_tort >= MAXPIX) { /* flush */ |
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rt_compute(rt_buf, npix_tort); |
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for (i = 0; i < npix_tort; i++) |
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vb[buf_vh[i]+hsize] = luminance(rt_buf+3*i); |
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npix_tort = 0; |
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} |
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rt_buf[npix_tort] = ourview.vp[0]; |
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rt_buf[npix_tort+1] = ourview.vp[1]; |
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rt_buf[npix_tort+2] = ourview.vp[2]; |
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rt_buf[npix_tort+3] = dir[0]; |
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rt_buf[npix_tort+4] = dir[1]; |
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rt_buf[npix_tort+5] = dir[2]; |
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buf_vh[npix_tort++] = vh; |
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} |
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if (npix_tort > 0) { /* process pending buffer */ |
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rt_compute(rt_buf, npix_tort); |
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for (i = 0; i < npix_tort; i++) |
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vb[buf_vh[i]+hsize] = luminance(rt_buf+3*i); |
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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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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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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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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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} |
