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/* Copyright (c) 1997 Silicon Graphics, Inc. */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ SGI"; |
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#endif |
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|
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/* |
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* Holodeck beam tracking for display process |
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*/ |
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|
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#include "rholo.h" |
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#include "rhdisp.h" |
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#include "rhdriver.h" |
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|
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extern GCOORD *getviewcells(); |
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|
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typedef struct { |
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int hd; /* holodeck section number (-1 if inactive) */ |
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int i[3]; /* voxel index (may be outside section) */ |
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} VOXL; /* a voxel */ |
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|
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static VOXL voxel[8] = { /* current voxel list */ |
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{-1}, {-1}, {-1}, {-1}, |
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{-1}, {-1}, {-1}, {-1} |
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}; |
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|
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#define CBEAMBLK 1024 /* cbeam allocation block size */ |
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|
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static struct beamcomp { |
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short wants; /* flags telling which voxels want us */ |
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short hd; /* holodeck section number */ |
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int bi; /* beam index */ |
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} *cbeam = NULL; /* current beam list */ |
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|
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static int ncbeams = 0; /* number of sorted beams in cbeam */ |
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static int xcbeams = 0; /* extra (unregistered) beams past ncbeams */ |
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static int maxcbeam = 0; /* size of cbeam array */ |
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|
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struct cellact { |
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short vi; /* voxel index */ |
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short add; /* zero means delete */ |
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short rev; /* reverse ray direction? */ |
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}; /* action for cell */ |
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|
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struct beamact { |
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struct cellact ca; /* cell action */ |
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GCOORD gc; /* grid coordinate */ |
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}; /* beam origin and action */ |
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|
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|
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int |
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newcbeam() /* allocate new entry at end of cbeam array */ |
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{ |
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int i; |
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|
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if ((i = ncbeams + xcbeams++) >= maxcbeam) { /* grow array */ |
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maxcbeam += CBEAMBLK; |
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if (cbeam == NULL) |
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cbeam = (struct beamcomp *)malloc( |
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maxcbeam*sizeof(struct beamcomp) ); |
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else |
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cbeam = (struct beamcomp *)realloc( (char *)cbeam, |
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maxcbeam*sizeof(struct beamcomp) ); |
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if (cbeam == NULL) |
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error(SYSTEM, "out of memory in newcbeam"); |
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} |
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return(i); |
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} |
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|
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|
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int |
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cbeamcmp(cb1, cb2) /* compare two cbeam entries for sort: keep orphans */ |
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register struct beamcomp *cb1, *cb2; |
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{ |
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register int c; |
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|
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if ((c = cb1->bi - cb2->bi)) /* sort on beam index first */ |
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return(c); |
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return(cb1->hd - cb2->hd); /* use hd to resolve matches */ |
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} |
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|
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|
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int |
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cbeamcmp2(cb1, cb2) /* compare two cbeam entries for sort: no orphans */ |
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register struct beamcomp *cb1, *cb2; |
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{ |
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register int c; |
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|
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if (!cb1->wants) /* put orphans at the end, unsorted */ |
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return(cb2->wants); |
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if ((c = cb1->bi - cb2->bi)) /* sort on beam index first */ |
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return(c); |
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return(cb1->hd - cb2->hd); /* use hd to resolve matches */ |
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} |
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|
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|
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int |
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findcbeam(hd, bi) /* find the specified beam in our sorted list */ |
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int hd, bi; |
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{ |
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struct beamcomp cb; |
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register struct beamcomp *p; |
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|
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if (ncbeams <= 0) |
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return(-1); |
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cb.wants = 0; cb.hd = hd; cb.bi = bi; |
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p = (struct beamcomp *)bsearch((char *)&cb, (char *)cbeam, ncbeams, |
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sizeof(struct beamcomp), cbeamcmp); |
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if (p == NULL) |
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return(-1); |
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return(p - cbeam); |
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} |
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|
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|
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int |
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getcbeam(hd, bi) /* get the specified beam, allocating as necessary */ |
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register int hd; |
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int bi; |
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{ |
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register int n; |
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/* first, look in sorted list */ |
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if ((n = findcbeam(hd, bi)) >= 0) |
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return(n); |
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/* linear search through xcbeams to be sure */ |
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for (n = ncbeams+xcbeams; n-- > ncbeams; ) |
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if (cbeam[n].bi == bi && cbeam[n].hd == hd) |
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return(n); |
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/* check legality */ |
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if (hd < 0 | hd >= HDMAX || hdlist[hd] == NULL) |
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error(INTERNAL, "illegal holodeck number in getcbeam"); |
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if (bi < 1 | bi > nbeams(hdlist[hd])) |
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error(INTERNAL, "illegal beam index in getcbeam"); |
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n = newcbeam(); /* allocate and assign */ |
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cbeam[n].wants = 0; cbeam[n].hd = hd; cbeam[n].bi = bi; |
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return(n); |
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} |
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|
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|
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cbeamsort(adopt) /* sort our beam list, possibly turning out orphans */ |
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int adopt; |
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{ |
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register int i; |
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|
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if (!(ncbeams += xcbeams)) |
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return; |
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xcbeams = 0; |
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qsort((char *)cbeam, ncbeams, sizeof(struct beamcomp), |
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adopt ? cbeamcmp : cbeamcmp2); |
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if (adopt) |
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return; |
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for (i = ncbeams; i--; ) /* identify orphans */ |
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if (cbeam[i].wants) |
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break; |
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xcbeams = ncbeams - ++i; /* put orphans after ncbeams */ |
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ncbeams = i; |
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} |
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|
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|
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cbeamop(op, bl, n, v, hr, vr) /* update beams on server list */ |
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int op; |
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register struct beamcomp *bl; |
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int n; |
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VIEW *v; |
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int hr, vr; |
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{ |
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register PACKHEAD *pa; |
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register int i; |
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|
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if (n <= 0) |
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return; |
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pa = (PACKHEAD *)malloc(n*sizeof(PACKHEAD)); |
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if (pa == NULL) |
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error(SYSTEM, "out of memory in cbeamadd"); |
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for (i = 0; i < n; i++) { |
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pa[i].hd = bl[i].hd; |
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pa[i].bi = bl[i].bi; |
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pa[i].nr = v==NULL ? 0 : |
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npixels(v, hr, vr, hdlist[bl[i].hd], bl[i].bi); |
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} |
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serv_request(op, n*sizeof(PACKHEAD), (char *)pa); |
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free((char *)pa); |
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} |
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|
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|
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int |
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set_voxels(vl, n) /* set new voxel array */ |
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VOXL vl[8]; |
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int n; |
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{ |
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short wmap[256]; |
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int vmap[8]; |
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int comn = 0; |
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int no; |
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register int i, j; |
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/* find common voxels */ |
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for (j = 0; j < 8 && voxel[j].hd >= 0; j++) { |
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vmap[j] = -1; |
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for (i = n; i--; ) |
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if (!bcmp((char *)(vl+i), (char *)(voxel+j), |
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sizeof(VOXL))) { |
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vmap[j] = i; |
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comn |= 1<<i; |
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break; |
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} |
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} |
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no = comn ? j : 0; /* compute flag mapping */ |
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for (i = 256; i--; ) { |
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wmap[i] = 0; |
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for (j = no; j--; ) |
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if (vmap[j] >= 0 && i & 1<<j) |
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wmap[i] |= 1<<vmap[j]; |
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} |
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/* fix cbeam flags */ |
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for (i = ncbeams; i--; ) |
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cbeam[i].wants = wmap[cbeam[i].wants]; |
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/* update our voxel list */ |
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bcopy((char *)vl, (char *)voxel, n*sizeof(VOXL)); |
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for (j = n; j < 8; j++) |
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voxel[j].hd = -1; |
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return(comn); /* return bit array of common voxels */ |
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} |
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|
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|
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int |
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get_voxels(vl, vp) /* find voxels corresponding to view point */ |
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VOXL vl[8]; |
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FVECT vp; |
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{ |
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static int lastn = 0, lastd = -1; |
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int n = 0; |
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FVECT gp; |
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double d; |
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int dist, bestd = 0x7fff; |
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VOXL vox; |
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register int i, j, k; |
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/* find closest voxels */ |
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for (i = 0; n < 8 && hdlist[i]; i++) { |
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hdgrid(gp, hdlist[i], vp); |
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for (j = 0; n < 8 && j < 8; j++) { |
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dist = 0; |
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for (k = 0; k < 3; k++) { |
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d = gp[k] - .5 + (j>>k & 1); |
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if (d < 0.) |
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dist += -(vox.i[k] = (int)d - 1); |
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else if ((vox.i[k] = d) >= hdlist[i]->grid[k]) |
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dist += vox.i[k] - |
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hdlist[i]->grid[k] + 1; |
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} |
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if (dist > bestd) /* others were closer */ |
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continue; |
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if (dist < bestd) { /* start closer list */ |
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n = 0; |
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bestd = dist; |
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} |
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vox.hd = i; /* add this voxel */ |
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copystruct(&vl[n], &vox); |
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n++; |
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} |
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} |
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/* warn of dangerous moves */ |
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if (n < lastn && bestd >= lastd) |
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error(WARNING, "moving outside holodeck section"); |
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else if (n > lastn && bestd <= lastd) |
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error(WARNING, "moving inside holodeck section"); |
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lastd = bestd; |
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return(lastn = n); |
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} |
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|
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|
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int |
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dobeam(gcp, bp) /* express interest or disintrest in a beam */ |
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GCOORD *gcp; |
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register struct beamact *bp; |
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{ |
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GCOORD gc[2]; |
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int bi, i; |
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/* compute beam index */ |
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if (bp->ca.rev) { |
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copystruct(gc, &bp->gc); |
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copystruct(gc+1, gcp); |
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} else { |
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copystruct(gc, gcp); |
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copystruct(gc+1, &bp->gc); |
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} |
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if ((bi = hdbindex(hdlist[voxel[bp->ca.vi].hd], gc)) <= 0) |
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error(CONSISTENCY, "bad grid coordinate in dobeam"); |
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if (bp->ca.add) { /* add it in */ |
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i = getcbeam(voxel[bp->ca.vi].hd, bi); |
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cbeam[i].wants |= 1<<bp->ca.vi; /* say we want it */ |
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return(i == ncbeams+xcbeams-1); /* return 1 if totally new */ |
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} |
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/* else delete it */ |
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i = findcbeam(voxel[bp->ca.vi].hd, bi); |
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if (i >= 0 && cbeam[i].wants & 1<<bp->ca.vi) { |
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cbeam[i].wants &= ~(1<<bp->ca.vi); /* we don't want it */ |
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return(1); /* indicate change */ |
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} |
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return(0); |
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} |
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|
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|
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|
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int |
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docell(gcp, cap) /* find beams corresponding to cell and voxel */ |
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GCOORD *gcp; |
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register struct cellact *cap; |
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{ |
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FVECT org, dir[4]; |
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FVECT gp, cv[4], vc; |
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struct beamact bo; |
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register int i; |
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/* compute cell vertices */ |
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hdcell(cv, hdlist[voxel[cap->vi].hd], gcp); |
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/* compute cell and voxel centers */ |
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for (i = 0; i < 3; i++) { |
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org[i] = 0.5*(cv[0][i] + cv[2][i]); |
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gp[i] = voxel[cap->vi].i[i] + 0.5; |
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} |
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hdworld(vc, hdlist[voxel[cap->vi].hd], gp); |
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/* compute voxel pyramid using vector trick */ |
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for (i = 0; i < 3; i++) { |
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dir[0][i] = vc[i] - cv[0][i]; /* to 3 */ |
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dir[2][i] = vc[i] - cv[3][i]; /* to 0 */ |
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if (gcp->w & 1) { /* watch vertex order! */ |
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dir[1][i] = vc[i] - cv[2][i]; /* to 1 */ |
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dir[3][i] = vc[i] - cv[1][i]; /* to 2 */ |
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} else { |
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dir[1][i] = vc[i] - cv[1][i]; /* to 2 */ |
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dir[3][i] = vc[i] - cv[2][i]; /* to 1 */ |
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} |
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} |
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/* visit beams for opposite cells */ |
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copystruct(&bo.ca, cap); |
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copystruct(&bo.gc, gcp); |
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return(visit_cells(org, dir, hdlist[voxel[cap->vi].hd], dobeam, &bo)); |
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} |
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|
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|
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int |
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doview(cap, vp) /* visit cells for a given view */ |
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struct cellact *cap; |
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VIEW *vp; |
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{ |
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int orient; |
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FVECT org, dir[4]; |
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/* compute view pyramid */ |
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orient = viewpyramid(org, dir, hdlist[voxel[cap->vi].hd], vp); |
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if (!orient) |
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error(INTERNAL, "unusable view in doview"); |
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cap->rev = orient < 0; |
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/* visit cells within pyramid */ |
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return(visit_cells(org, dir, hdlist[voxel[cap->vi].hd], docell, cap)); |
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} |
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|
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|
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mvview(voxi, vold, vnew) /* move view for a voxel */ |
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int voxi; |
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VIEW *vold, *vnew; |
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{ |
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int netchange = 0; |
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struct cellact oca, nca; |
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int ocnt, ncnt; |
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int c; |
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register GCOORD *ogcp, *ngcp; |
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/* get old and new cell lists */ |
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ogcp = getviewcells(&ocnt, hdlist[voxel[voxi].hd], vold); |
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ngcp = getviewcells(&ncnt, hdlist[voxel[voxi].hd], vnew); |
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/* set up actions */ |
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oca.vi = nca.vi = voxi; |
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oca.rev = nca.rev = 0; |
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oca.add = 0; nca.add = 1; |
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if ((oca.rev = ocnt < 0)) |
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ocnt = -ocnt; |
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if ((nca.rev = ncnt < 0)) |
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ncnt = -ncnt; |
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/* add and delete cells in order */ |
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while (ocnt > 0 & ncnt > 0) |
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if ((c = cellcmp(ogcp, ngcp)) > 0) { /* new cell */ |
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netchange += docell(ngcp++, &nca); |
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ncnt--; |
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} else if (c < 0) { /* obsolete cell */ |
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netchange -= docell(ogcp++, &oca); |
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ocnt--; |
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} else { /* same cell? */ |
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if (oca.rev != nca.rev) /* not */ |
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netchange += docell(ngcp, &nca) - |
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docell(ogcp, &oca); |
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ogcp++; ocnt--; |
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ngcp++; ncnt--; |
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} |
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/* take care of list tails */ |
| 392 |
for ( ; ncnt > 0; ncnt--) |
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netchange += docell(ngcp++, &nca); |
| 394 |
for ( ; ocnt > 0; ocnt--) |
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netchange -= docell(ogcp++, &oca); |
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/* clean up */ |
| 397 |
if (ogcp != NULL) free((char *)ogcp); |
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if (ngcp != NULL) free((char *)ngcp); |
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return(netchange); |
| 400 |
} |
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|
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|
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beam_sync() /* synchronize beams on server */ |
| 404 |
{ |
| 405 |
cbeamop(DR_NEWSET, cbeam, ncbeams, &odev.v, odev.hres, odev.vres); |
| 406 |
} |
| 407 |
|
| 408 |
|
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beam_view(vo, vn) /* change beam view */ |
| 410 |
VIEW *vo, *vn; |
| 411 |
{ |
| 412 |
struct cellact ca; |
| 413 |
VOXL vlnew[8]; |
| 414 |
int n, comn; |
| 415 |
|
| 416 |
if (!vn->type) { /* clear our beam list */ |
| 417 |
set_voxels(vlnew, 0); |
| 418 |
cbeamop(DR_DELSET, cbeam, ncbeams, NULL, 0, 0); |
| 419 |
ncbeams = 0; |
| 420 |
return; |
| 421 |
} |
| 422 |
/* find our new voxels */ |
| 423 |
n = get_voxels(vlnew, vn->vp); |
| 424 |
/* set the new voxels */ |
| 425 |
comn = set_voxels(vlnew, n); |
| 426 |
if (!vo->type) |
| 427 |
comn = 0; |
| 428 |
ca.add = 1; /* update our beam list */ |
| 429 |
for (ca.vi = n; ca.vi--; ) |
| 430 |
if (comn & 1<<ca.vi) /* change which cells we see */ |
| 431 |
mvview(ca.vi, vo, vn); |
| 432 |
else /* else add all new cells */ |
| 433 |
doview(&ca, vn); |
| 434 |
/* inform server of new beams */ |
| 435 |
cbeamop(DR_ADDSET, cbeam+ncbeams, xcbeams, vn, odev.hres, odev.vres); |
| 436 |
/* sort list to put orphans at end */ |
| 437 |
cbeamsort(0); |
| 438 |
/* tell server to delete orphans */ |
| 439 |
cbeamop(DR_DELSET, cbeam+ncbeams, xcbeams, NULL, 0, 0); |
| 440 |
xcbeams = 0; /* truncate our list */ |
| 441 |
} |
