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/* Copyright (c) 1993 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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* ambient.c - routines dealing with ambient (inter-reflected) component. |
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*/ |
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|
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#include "ray.h" |
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|
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#include "octree.h" |
14 |
|
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#include "otypes.h" |
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|
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#include "ambient.h" |
18 |
|
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#include "random.h" |
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|
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#define OCTSCALE 0.5 /* ceil((valid rad.)/(cube size)) */ |
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|
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typedef struct ambtree { |
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AMBVAL *alist; /* ambient value list */ |
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struct ambtree *kid; /* 8 child nodes */ |
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} AMBTREE; /* ambient octree */ |
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|
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extern CUBE thescene; /* contains space boundaries */ |
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|
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#define MAXASET 511 /* maximum number of elements in ambient set */ |
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OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */ |
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|
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double maxarad; /* maximum ambient radius */ |
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double minarad; /* minimum ambient radius */ |
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|
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static AMBTREE atrunk; /* our ambient trunk node */ |
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|
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static FILE *ambfp = NULL; /* ambient file pointer */ |
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static int nunflshed = 0; /* number of unflushed ambient values */ |
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|
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#define AMBFLUSH (BUFSIZ/AMBVALSIZ) |
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|
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#define newambval() (AMBVAL *)bmalloc(sizeof(AMBVAL)) |
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|
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#define newambtree() (AMBTREE *)calloc(8, sizeof(AMBTREE)) |
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#define freeambtree(t) free((char *)(t)) |
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|
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extern long ftell(), lseek(); |
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static int initambfile(), avsave(), avinsert(), loadtree(); |
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static AMBVAL *avstore(); |
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#ifdef F_SETLKW |
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static aflock(); |
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#endif |
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|
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|
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setambres(ar) /* set ambient resolution */ |
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int ar; |
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{ |
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ambres = ar; /* may be done already */ |
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/* set min & max radii */ |
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if (ar <= 0) { |
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minarad = 0.0; |
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maxarad = thescene.cusize / 2.0; |
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} else { |
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minarad = thescene.cusize / ar; |
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maxarad = 16.0 * minarad; /* heuristic */ |
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if (maxarad > thescene.cusize / 2.0) |
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maxarad = thescene.cusize / 2.0; |
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} |
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if (maxarad <= FTINY) |
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maxarad = .001; |
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} |
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|
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|
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resetambacc(newa) /* change ambient accuracy setting */ |
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double newa; |
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{ |
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AMBTREE oldatrunk; |
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|
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if (fabs(newa - ambacc) < 0.01) |
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return; /* insignificant -- don't bother */ |
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ambacc = newa; |
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if (ambacc <= FTINY) |
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return; /* cannot build new tree */ |
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/* else need to rebuild tree */ |
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copystruct(&oldatrunk, &atrunk); |
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atrunk.alist = NULL; |
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atrunk.kid = NULL; |
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loadtree(&oldatrunk); |
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} |
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|
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|
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setambient(afile) /* initialize calculation */ |
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char *afile; |
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{ |
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long headlen; |
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AMBVAL amb; |
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/* init ambient limits */ |
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setambres(ambres); |
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if (afile == NULL) |
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return; |
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if (ambacc <= FTINY) { |
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sprintf(errmsg, "zero ambient accuracy so \"%s\" not loaded", |
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afile); |
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error(WARNING, errmsg); |
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return; |
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} |
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/* open ambient file */ |
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if ((ambfp = fopen(afile, "r+")) != NULL) { |
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initambfile(0); |
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headlen = ftell(ambfp); |
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while (readambval(&amb, ambfp)) |
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avinsert(avstore(&amb), &atrunk, |
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thescene.cuorg, thescene.cusize); |
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/* align */ |
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fseek(ambfp, -((ftell(ambfp)-headlen)%AMBVALSIZ), 1); |
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} else if ((ambfp = fopen(afile, "w+")) != NULL) |
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initambfile(1); |
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else { |
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sprintf(errmsg, "cannot open ambient file \"%s\"", afile); |
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error(SYSTEM, errmsg); |
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} |
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nunflshed++; /* lie */ |
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ambsync(); |
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} |
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|
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|
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ambnotify(obj) /* record new modifier */ |
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OBJECT obj; |
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{ |
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static int hitlimit = 0; |
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register OBJREC *o = objptr(obj); |
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register char **amblp; |
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|
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if (hitlimit || !ismodifier(o->otype)) |
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return; |
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for (amblp = amblist; *amblp != NULL; amblp++) |
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if (!strcmp(o->oname, *amblp)) { |
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if (ambset[0] >= MAXASET) { |
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error(WARNING, "too many modifiers in ambient list"); |
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hitlimit++; |
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return; /* should this be fatal? */ |
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} |
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insertelem(ambset, obj); |
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return; |
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} |
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} |
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|
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|
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ambient(acol, r) /* compute ambient component for ray */ |
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COLOR acol; |
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register RAY *r; |
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{ |
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static int rdepth = 0; /* ambient recursion */ |
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double d; |
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|
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if (ambdiv <= 0) /* no ambient calculation */ |
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goto dumbamb; |
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/* check number of bounces */ |
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if (rdepth >= ambounce) |
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goto dumbamb; |
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/* check ambient list */ |
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if (ambincl != -1 && r->ro != NULL && |
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ambincl != inset(ambset, r->ro->omod)) |
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goto dumbamb; |
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|
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if (ambacc <= FTINY) { /* no ambient storage */ |
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rdepth++; |
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d = doambient(acol, r, r->rweight, NULL, NULL); |
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rdepth--; |
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if (d == 0.0) |
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goto dumbamb; |
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return; |
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} |
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/* get ambient value */ |
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setcolor(acol, 0.0, 0.0, 0.0); |
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d = sumambient(acol, r, rdepth, |
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&atrunk, thescene.cuorg, thescene.cusize); |
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if (d > FTINY) |
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scalecolor(acol, 1.0/d); |
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else { |
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d = makeambient(acol, r, rdepth++); |
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rdepth--; |
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} |
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if (d > FTINY) |
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return; |
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dumbamb: /* return global value */ |
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copycolor(acol, ambval); |
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} |
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|
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|
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double |
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sumambient(acol, r, al, at, c0, s) /* get interpolated ambient value */ |
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COLOR acol; |
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register RAY *r; |
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int al; |
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AMBTREE *at; |
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FVECT c0; |
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double s; |
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{ |
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double d, e1, e2, wt, wsum; |
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COLOR ct; |
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FVECT ck0; |
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int i; |
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register int j; |
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register AMBVAL *av; |
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/* do this node */ |
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wsum = 0.0; |
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for (av = at->alist; av != NULL; av = av->next) { |
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/* |
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* Ambient level test. |
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*/ |
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if (av->lvl > al || av->weight < r->rweight-FTINY) |
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continue; |
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/* |
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* Ambient radius test. |
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*/ |
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e1 = 0.0; |
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for (j = 0; j < 3; j++) { |
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d = av->pos[j] - r->rop[j]; |
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e1 += d * d; |
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} |
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e1 /= av->rad * av->rad; |
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if (e1 > ambacc*ambacc*1.21) |
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continue; |
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/* |
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* Normal direction test. |
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*/ |
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e2 = (1.0 - DOT(av->dir, r->ron)) * r->rweight; |
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if (e2 < 0.0) e2 = 0.0; |
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if (e1 + e2 > ambacc*ambacc*1.21) |
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continue; |
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/* |
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* Ray behind test. |
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*/ |
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d = 0.0; |
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for (j = 0; j < 3; j++) |
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d += (r->rop[j] - av->pos[j]) * |
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(av->dir[j] + r->ron[j]); |
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if (d*0.5 < -minarad*ambacc-.001) |
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continue; |
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/* |
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* Jittering final test reduces image artifacts. |
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*/ |
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wt = sqrt(e1) + sqrt(e2); |
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wt *= .9 + .2*urand(9015+samplendx); |
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if (wt > ambacc) |
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continue; |
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if (wt <= 1e-3) |
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wt = 1e3; |
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else |
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wt = 1.0 / wt; |
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wsum += wt; |
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extambient(ct, av, r->rop, r->ron); |
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scalecolor(ct, wt); |
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addcolor(acol, ct); |
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} |
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if (at->kid == NULL) |
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return(wsum); |
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/* do children */ |
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s *= 0.5; |
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for (i = 0; i < 8; i++) { |
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for (j = 0; j < 3; j++) { |
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ck0[j] = c0[j]; |
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if (1<<j & i) |
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ck0[j] += s; |
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if (r->rop[j] < ck0[j] - OCTSCALE*s) |
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break; |
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if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s) |
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break; |
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} |
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if (j == 3) |
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wsum += sumambient(acol, r, al, at->kid+i, ck0, s); |
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} |
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return(wsum); |
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} |
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|
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|
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double |
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makeambient(acol, r, al) /* make a new ambient value */ |
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COLOR acol; |
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register RAY *r; |
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int al; |
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{ |
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AMBVAL amb; |
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FVECT gp, gd; |
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/* compute weight */ |
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amb.weight = pow(AVGREFL, (double)al); |
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if (r->rweight < 0.2*amb.weight) /* heuristic */ |
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amb.weight = r->rweight; |
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/* compute ambient */ |
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amb.rad = doambient(acol, r, amb.weight, gp, gd); |
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if (amb.rad == 0.0) |
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return(0.0); |
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/* store it */ |
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VCOPY(amb.pos, r->rop); |
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VCOPY(amb.dir, r->ron); |
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amb.lvl = al; |
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copycolor(amb.val, acol); |
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VCOPY(amb.gpos, gp); |
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VCOPY(amb.gdir, gd); |
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/* insert into tree */ |
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avsave(&amb); /* and save to file */ |
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return(amb.rad); |
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} |
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|
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|
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extambient(cr, ap, pv, nv) /* extrapolate value at pv, nv */ |
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COLOR cr; |
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register AMBVAL *ap; |
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FVECT pv, nv; |
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{ |
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FVECT v1, v2; |
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register int i; |
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double d; |
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|
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d = 1.0; /* zeroeth order */ |
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/* gradient due to translation */ |
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for (i = 0; i < 3; i++) |
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d += ap->gpos[i]*(pv[i]-ap->pos[i]); |
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/* gradient due to rotation */ |
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VCOPY(v1, ap->dir); |
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fcross(v2, v1, nv); |
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d += DOT(ap->gdir, v2); |
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if (d <= 0.0) { |
326 |
setcolor(cr, 0.0, 0.0, 0.0); |
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return; |
328 |
} |
329 |
copycolor(cr, ap->val); |
330 |
scalecolor(cr, d); |
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} |
332 |
|
333 |
|
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static |
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initambfile(creat) /* initialize ambient file */ |
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int creat; |
337 |
{ |
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extern char *progname, *octname, VersionID[]; |
339 |
|
340 |
#ifdef F_SETLKW |
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aflock(creat ? F_WRLCK : F_RDLCK); |
342 |
#endif |
343 |
#ifdef MSDOS |
344 |
setmode(fileno(ambfp), O_BINARY); |
345 |
#endif |
346 |
setbuf(ambfp, bmalloc(BUFSIZ)); |
347 |
if (creat) { /* new file */ |
348 |
fprintf(ambfp, "%s -av %g %g %g -ab %d -aa %g ", |
349 |
progname, colval(ambval,RED), |
350 |
colval(ambval,GRN), colval(ambval,BLU), |
351 |
ambounce, ambacc); |
352 |
fprintf(ambfp, "-ad %d -as %d -ar %d %s\n", |
353 |
ambdiv, ambssamp, ambres, |
354 |
octname==NULL ? "" : octname); |
355 |
fprintf(ambfp, "SOFTWARE= %s\n", VersionID); |
356 |
fputformat(AMBFMT, ambfp); |
357 |
putc('\n', ambfp); |
358 |
putambmagic(ambfp); |
359 |
} else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp)) |
360 |
error(USER, "bad ambient file"); |
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} |
362 |
|
363 |
|
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static |
365 |
avsave(av) /* insert and save an ambient value */ |
366 |
AMBVAL *av; |
367 |
{ |
368 |
avinsert(avstore(av), &atrunk, thescene.cuorg, thescene.cusize); |
369 |
if (ambfp == NULL) |
370 |
return; |
371 |
if (writambval(av, ambfp) < 0) |
372 |
goto writerr; |
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if (++nunflshed >= AMBFLUSH) |
374 |
if (ambsync() == EOF) |
375 |
goto writerr; |
376 |
return; |
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writerr: |
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error(SYSTEM, "error writing ambient file"); |
379 |
} |
380 |
|
381 |
|
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static AMBVAL * |
383 |
avstore(aval) /* allocate memory and store aval */ |
384 |
register AMBVAL *aval; |
385 |
{ |
386 |
register AMBVAL *av; |
387 |
|
388 |
if ((av = newambval()) == NULL) |
389 |
error(SYSTEM, "out of memory in avstore"); |
390 |
copystruct(av, aval); |
391 |
return(av); |
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} |
393 |
|
394 |
|
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static |
396 |
avinsert(av, at, c0, s) /* insert ambient value in a tree */ |
397 |
register AMBVAL *av; |
398 |
register AMBTREE *at; |
399 |
FVECT c0; |
400 |
double s; |
401 |
{ |
402 |
FVECT ck0; |
403 |
int branch; |
404 |
register int i; |
405 |
|
406 |
if (av->rad <= FTINY) |
407 |
error(CONSISTENCY, "zero ambient radius in avinsert"); |
408 |
VCOPY(ck0, c0); |
409 |
while (s*(OCTSCALE/2) > av->rad*ambacc) { |
410 |
if (at->kid == NULL) |
411 |
if ((at->kid = newambtree()) == NULL) |
412 |
error(SYSTEM, "out of memory in avinsert"); |
413 |
s *= 0.5; |
414 |
branch = 0; |
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for (i = 0; i < 3; i++) |
416 |
if (av->pos[i] > ck0[i] + s) { |
417 |
ck0[i] += s; |
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branch |= 1 << i; |
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} |
420 |
at = at->kid + branch; |
421 |
} |
422 |
av->next = at->alist; |
423 |
at->alist = av; |
424 |
} |
425 |
|
426 |
|
427 |
static |
428 |
loadtree(at) /* move tree to main store */ |
429 |
register AMBTREE *at; |
430 |
{ |
431 |
register AMBVAL *av; |
432 |
register int i; |
433 |
/* transfer values at this node */ |
434 |
for (av = at->alist; av != NULL; av = at->alist) { |
435 |
at->alist = av->next; |
436 |
avinsert(av, &atrunk, thescene.cuorg, thescene.cusize); |
437 |
} |
438 |
for (i = 0; i < 8; i++) /* transfer and free children */ |
439 |
loadtree(at->kid+i); |
440 |
freeambtree(at->kid); |
441 |
} |
442 |
|
443 |
|
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#ifdef F_SETLKW |
445 |
|
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static |
447 |
aflock(typ) /* lock/unlock ambient file */ |
448 |
int typ; |
449 |
{ |
450 |
static struct flock fls; /* static so initialized to zeroes */ |
451 |
|
452 |
fls.l_type = typ; |
453 |
if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0) |
454 |
error(SYSTEM, "cannot (un)lock ambient file"); |
455 |
} |
456 |
|
457 |
|
458 |
int |
459 |
ambsync() /* synchronize ambient file */ |
460 |
{ |
461 |
static FILE *ambinp = NULL; |
462 |
static long lastpos = -1; |
463 |
long flen; |
464 |
AMBVAL avs; |
465 |
register int n; |
466 |
|
467 |
if (nunflshed == 0) |
468 |
return(0); |
469 |
if (lastpos < 0) /* initializing (locked in initambfile) */ |
470 |
goto syncend; |
471 |
/* gain exclusive access */ |
472 |
aflock(F_WRLCK); |
473 |
/* see if file has grown */ |
474 |
if ((flen = lseek(fileno(ambfp), 0L, 2)) < 0) |
475 |
error(SYSTEM, "cannot seek on ambient file"); |
476 |
if (n = flen - lastpos) { /* file has grown */ |
477 |
if (ambinp == NULL) { /* use duplicate filedes */ |
478 |
ambinp = fdopen(dup(fileno(ambfp)), "r"); |
479 |
if (ambinp == NULL) |
480 |
error(SYSTEM, "fdopen failed in ambsync"); |
481 |
} |
482 |
if (fseek(ambinp, lastpos, 0) < 0) |
483 |
error(SYSTEM, "fseek failed in ambsync"); |
484 |
while (n >= AMBVALSIZ) { /* load contributed values */ |
485 |
readambval(&avs, ambinp); |
486 |
avinsert(avstore(&avs), &atrunk, |
487 |
thescene.cuorg, thescene.cusize); |
488 |
n -= AMBVALSIZ; |
489 |
} |
490 |
if (n) /* alignment */ |
491 |
lseek(fileno(ambfp), flen-n, 0); |
492 |
} |
493 |
syncend: |
494 |
n = fflush(ambfp); /* calls write() at last */ |
495 |
lastpos = lseek(fileno(ambfp), 0L, 1); |
496 |
aflock(F_UNLCK); /* release file */ |
497 |
nunflshed = 0; |
498 |
return(n); |
499 |
} |
500 |
|
501 |
#else |
502 |
|
503 |
int |
504 |
ambsync() /* flush ambient file */ |
505 |
{ |
506 |
if (nunflshed == 0) |
507 |
return(0); |
508 |
nunflshed = 0; |
509 |
return(fflush(ambfp)); |
510 |
} |
511 |
|
512 |
#endif |