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root/radiance/ray/src/rt/ambient.c
Revision: 2.115
Committed: Mon Apr 25 03:38:30 2022 UTC (2 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.114: +5 -4 lines
Log Message:
perf: Added a few more relevant options to ambient file header

File Contents

# Content
1 static const char RCSid[] = "$Id: ambient.c,v 2.114 2022/04/11 00:45:30 greg Exp $";
2 /*
3 * ambient.c - routines dealing with ambient (inter-reflected) component.
4 *
5 * Declarations of external symbols in ambient.h
6 */
7
8 #include "copyright.h"
9
10 #include <string.h>
11
12 #include "platform.h"
13 #include "ray.h"
14 #include "otypes.h"
15 #include "otspecial.h"
16 #include "resolu.h"
17 #include "ambient.h"
18 #include "random.h"
19 #include "pmapamb.h"
20
21 #ifndef OCTSCALE
22 #define OCTSCALE 1.0 /* ceil((valid rad.)/(cube size)) */
23 #endif
24
25 #ifndef MAXASET
26 #define MAXASET 4095 /* maximum number of elements in ambient set */
27 #endif
28 OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
29
30 double maxarad; /* maximum ambient radius */
31 double minarad; /* minimum ambient radius */
32
33 static AMBTREE atrunk; /* our ambient trunk node */
34
35 static FILE *ambfp = NULL; /* ambient file pointer */
36 static int nunflshed = 0; /* number of unflushed ambient values */
37
38 static double avsum = 0.; /* computed ambient value sum (log) */
39 static unsigned int navsum = 0; /* number of values in avsum */
40 static unsigned int nambvals = 0; /* total number of indirect values */
41 static unsigned int nambshare = 0; /* number of values from file */
42 static FILE *ambinp = NULL; /* auxiliary file for input */
43 static long lastpos = -1; /* last flush position */
44
45 #define AMBFLUSH (BUFSIZ/AMBVALSIZ)
46
47 #define newambval() (AMBVAL *)malloc(sizeof(AMBVAL))
48
49 #define tfunc(lwr, x, upr) (((x)-(lwr))/((upr)-(lwr)))
50
51 static void initambfile(int creat);
52 static void avsave(AMBVAL *av);
53 static AMBVAL *avstore(AMBVAL *aval);
54 static AMBTREE *newambtree(void);
55 static void freeambtree(AMBTREE *atp);
56
57 typedef void unloadtf_t(AMBVAL *);
58 static unloadtf_t avinsert;
59 static unloadtf_t avfree;
60 static void unloadatree(AMBTREE *at, unloadtf_t *f);
61
62 static void sortambvals(void);
63
64 static int plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang);
65 static double sumambient(COLOR acol, RAY *r, FVECT rn, int al,
66 AMBTREE *at, FVECT c0, double s);
67 static int makeambient(COLOR acol, RAY *r, FVECT rn, int al);
68 static int extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv,
69 FVECT uvw[3]);
70
71 #ifdef F_SETLKW
72 static void aflock(int typ);
73 #endif
74
75
76 void
77 setambres( /* set ambient resolution */
78 int ar
79 )
80 {
81 ambres = ar < 0 ? 0 : ar; /* may be done already */
82 /* set min & max radii */
83 if (ar <= 0) {
84 minarad = 0;
85 maxarad = thescene.cusize*0.2;
86 } else {
87 minarad = thescene.cusize / ar;
88 maxarad = 64.0 * minarad; /* heuristic */
89 if (maxarad > thescene.cusize*0.2)
90 maxarad = thescene.cusize*0.2;
91 }
92 if (minarad <= FTINY)
93 minarad = 10.0*FTINY;
94 if (maxarad <= minarad)
95 maxarad = 64.0 * minarad;
96 }
97
98
99 void
100 setambacc( /* set ambient accuracy */
101 double newa
102 )
103 {
104 static double olda; /* remember previous setting here */
105
106 newa *= (newa > 0);
107 if (fabs(newa - olda) >= .05*(newa + olda)) {
108 ambacc = newa;
109 if (ambacc > FTINY && nambvals > 0)
110 sortambvals(); /* rebuild tree */
111 }
112 }
113
114
115 void
116 setambient(void) /* initialize calculation */
117 {
118 int readonly = 0;
119 long flen;
120 AMBVAL amb;
121 /* make sure we're fresh */
122 ambdone();
123 /* init ambient limits */
124 setambres(ambres);
125 setambacc(ambacc);
126 if (ambfile == NULL || !ambfile[0])
127 return;
128 if (ambacc <= FTINY) {
129 sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
130 ambfile);
131 error(WARNING, errmsg);
132 return;
133 }
134 /* open ambient file */
135 if ((ambfp = fopen(ambfile, "r+")) == NULL)
136 readonly = (ambfp = fopen(ambfile, "r")) != NULL;
137 if (ambfp != NULL) {
138 initambfile(0); /* file exists */
139 lastpos = ftell(ambfp);
140 while (readambval(&amb, ambfp))
141 avstore(&amb);
142 nambshare = nambvals; /* share loaded values */
143 if (readonly) {
144 sprintf(errmsg,
145 "loaded %u values from read-only ambient file",
146 nambvals);
147 error(WARNING, errmsg);
148 fclose(ambfp); /* close file so no writes */
149 ambfp = NULL;
150 return; /* avoid ambsync() */
151 }
152 /* align file pointer */
153 lastpos += (long)nambvals*AMBVALSIZ;
154 flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
155 if (flen != lastpos) {
156 sprintf(errmsg,
157 "ignoring last %ld values in ambient file (corrupted)",
158 (flen - lastpos)/AMBVALSIZ);
159 error(WARNING, errmsg);
160 fseek(ambfp, lastpos, SEEK_SET);
161 ftruncate(fileno(ambfp), (off_t)lastpos);
162 }
163 } else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
164 initambfile(1); /* else create new file */
165 fflush(ambfp);
166 lastpos = ftell(ambfp);
167 } else {
168 sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
169 error(SYSTEM, errmsg);
170 }
171 #ifdef F_SETLKW
172 aflock(F_UNLCK); /* release file */
173 #endif
174 }
175
176
177 void
178 ambdone(void) /* close ambient file and free memory */
179 {
180 if (ambfp != NULL) { /* close ambient file */
181 ambsync();
182 fclose(ambfp);
183 ambfp = NULL;
184 if (ambinp != NULL) {
185 fclose(ambinp);
186 ambinp = NULL;
187 }
188 lastpos = -1;
189 }
190 /* free ambient tree */
191 unloadatree(&atrunk, avfree);
192 /* reset state variables */
193 avsum = 0.;
194 navsum = 0;
195 nambvals = 0;
196 nambshare = 0;
197 }
198
199
200 void
201 ambnotify( /* record new modifier */
202 OBJECT obj
203 )
204 {
205 static int hitlimit = 0;
206 OBJREC *o;
207 char **amblp;
208
209 if (obj == OVOID) { /* starting over */
210 ambset[0] = 0;
211 hitlimit = 0;
212 return;
213 }
214 o = objptr(obj);
215 if (hitlimit || !ismodifier(o->otype))
216 return;
217 for (amblp = amblist; *amblp != NULL; amblp++)
218 if (!strcmp(o->oname, *amblp)) {
219 if (ambset[0] >= MAXASET) {
220 error(WARNING, "too many modifiers in ambient list");
221 hitlimit++;
222 return; /* should this be fatal? */
223 }
224 insertelem(ambset, obj);
225 return;
226 }
227 }
228
229
230 void
231 multambient( /* compute ambient component & multiply by coef. */
232 COLOR aval,
233 RAY *r,
234 FVECT nrm
235 )
236 {
237 static double logAvgAbsorp = 1;
238 static int rdepth = 0; /* ambient recursion */
239 COLOR acol, caustic;
240 int i, ok;
241 double d, l;
242
243 /* PMAP: Factor in ambient from photon map, if enabled and ray is
244 * ambient. Return as all ambient components accounted for, else
245 * continue. */
246 if (ambPmap(aval, r, rdepth))
247 return;
248
249 if (logAvgAbsorp > 0) /* exclude in -aw to avoid growth */
250 logAvgAbsorp = log(1.-AVGREFL);
251
252 /* PMAP: Factor in specular-diffuse ambient (caustics) from photon
253 * map, if enabled and ray is primary, else caustic is zero. Continue
254 * with RADIANCE ambient calculation */
255 copycolor(caustic, aval);
256 ambPmapCaustic(caustic, r, rdepth);
257
258 if (ambdiv <= 0) /* no ambient calculation */
259 goto dumbamb;
260 /* check number of bounces */
261 if (rdepth >= ambounce)
262 goto dumbamb;
263 /* check ambient list */
264 if (ambincl != -1 && r->ro != NULL &&
265 ambincl != inset(ambset, r->ro->omod))
266 goto dumbamb;
267
268 if (ambacc <= FTINY) { /* no ambient storage */
269 FVECT uvd[2];
270 float dgrad[2], *dgp = NULL;
271
272 if (nrm != r->ron && DOT(nrm,r->ron) < 0.9999)
273 dgp = dgrad; /* compute rotational grad. */
274 copycolor(acol, aval);
275 rdepth++;
276 ok = doambient(acol, r, r->rweight,
277 uvd, NULL, NULL, dgp, NULL);
278 rdepth--;
279 if (!ok)
280 goto dumbamb;
281 if ((ok > 0) & (dgp != NULL)) { /* apply texture */
282 FVECT v1;
283 VCROSS(v1, r->ron, nrm);
284 d = 1.0;
285 for (i = 3; i--; )
286 d += v1[i] * (dgp[0]*uvd[0][i] + dgp[1]*uvd[1][i]);
287 if (d >= 0.05)
288 scalecolor(acol, d);
289 }
290 copycolor(aval, acol);
291
292 /* PMAP: add in caustic */
293 addcolor(aval, caustic);
294 return;
295 }
296 /* interpolate ambient value */
297 setcolor(acol, 0.0, 0.0, 0.0);
298 d = sumambient(acol, r, nrm, rdepth,
299 &atrunk, thescene.cuorg, thescene.cusize);
300
301 if (d > FTINY) {
302 d = 1.0/d;
303 scalecolor(acol, d);
304 multcolor(aval, acol);
305
306 /* PMAP: add in caustic */
307 addcolor(aval, caustic);
308 return;
309 }
310
311 rdepth++; /* need to cache new value */
312 ok = makeambient(acol, r, nrm, rdepth-1);
313 rdepth--;
314
315 if (ok) {
316 multcolor(aval, acol); /* computed new value */
317
318 /* PMAP: add in caustic */
319 addcolor(aval, caustic);
320 return;
321 }
322
323 dumbamb: /* return global value */
324 if ((ambvwt <= 0) | (navsum == 0)) {
325 multcolor(aval, ambval);
326
327 /* PMAP: add in caustic */
328 addcolor(aval, caustic);
329 return;
330 }
331
332 l = bright(ambval); /* average in computations */
333 if (l > FTINY) {
334 d = (log(l)*(double)ambvwt + avsum + logAvgAbsorp*navsum) /
335 (double)(ambvwt + navsum);
336 d = exp(d) / l;
337 scalecolor(aval, d);
338 multcolor(aval, ambval); /* apply color of ambval */
339 } else {
340 d = exp( avsum/(double)navsum + logAvgAbsorp );
341 scalecolor(aval, d); /* neutral color */
342 }
343 }
344
345
346 /* Plug a potential leak where ambient cache value is occluded */
347 static int
348 plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang)
349 {
350 const double cost70sq = 0.1169778; /* cos(70deg)^2 */
351 RAY rtst;
352 FVECT vdif;
353 double normdot, ndotd, nadotd;
354 double a, b, c, t[2];
355
356 ang += 2.*PI*(ang < 0); /* check direction flags */
357 if ( !(ap->corral>>(int)(ang*(16./PI)) & 1) )
358 return(0);
359 /*
360 * Generate test ray, targeting 20 degrees above sample point plane
361 * along surface normal from cache position. This should be high
362 * enough to miss local geometry we don't really care about.
363 */
364 VSUB(vdif, ap->pos, r->rop);
365 normdot = DOT(anorm, r->ron);
366 ndotd = DOT(vdif, r->ron);
367 nadotd = DOT(vdif, anorm);
368 a = normdot*normdot - cost70sq;
369 b = 2.0*(normdot*ndotd - nadotd*cost70sq);
370 c = ndotd*ndotd - DOT(vdif,vdif)*cost70sq;
371 if (quadratic(t, a, b, c) != 2)
372 return(1); /* should rarely happen */
373 if (t[1] <= FTINY)
374 return(0); /* should fail behind test */
375 rayorigin(&rtst, SHADOW, r, NULL);
376 VSUM(rtst.rdir, vdif, anorm, t[1]); /* further dist. > plane */
377 rtst.rmax = normalize(rtst.rdir); /* short ray test */
378 while (localhit(&rtst, &thescene)) { /* check for occluder */
379 OBJREC *m = findmaterial(rtst.ro);
380 if (m != NULL && !istransp(m->otype) && !isBSDFproxy(m) &&
381 (rtst.clipset == NULL ||
382 !inset(rtst.clipset, rtst.ro->omod)))
383 return(1); /* plug light leak */
384 VCOPY(rtst.rorg, rtst.rop); /* skip invisible surface */
385 rtst.rmax -= rtst.rot;
386 rayclear(&rtst);
387 }
388 return(0); /* seems we're OK */
389 }
390
391
392 static double
393 sumambient( /* get interpolated ambient value */
394 COLOR acol,
395 RAY *r,
396 FVECT rn,
397 int al,
398 AMBTREE *at,
399 FVECT c0,
400 double s
401 )
402 { /* initial limit is 10 degrees plus ambacc radians */
403 const double minangle = 10.0 * PI/180.;
404 double maxangle = minangle + ambacc;
405 double wsum = 0.0;
406 FVECT ck0;
407 int i, j;
408 AMBVAL *av;
409
410 if (at->kid != NULL) { /* sum children first */
411 s *= 0.5;
412 for (i = 0; i < 8; i++) {
413 for (j = 0; j < 3; j++) {
414 ck0[j] = c0[j];
415 if (1<<j & i)
416 ck0[j] += s;
417 if (r->rop[j] < ck0[j] - OCTSCALE*s)
418 break;
419 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
420 break;
421 }
422 if (j == 3)
423 wsum += sumambient(acol, r, rn, al,
424 at->kid+i, ck0, s);
425 }
426 /* good enough? */
427 if (wsum >= 0.05 && s > minarad*10.0)
428 return(wsum);
429 }
430 /* adjust maximum angle */
431 if (at->alist != NULL && (at->alist->lvl <= al) & (r->rweight < 0.6))
432 maxangle = (maxangle - PI/2.)*pow(r->rweight,0.13) + PI/2.;
433 /* sum this node */
434 for (av = at->alist; av != NULL; av = av->next) {
435 double u, v, d, delta_r2, delta_t2;
436 COLOR ct;
437 FVECT uvw[3];
438 /*
439 * Ambient level test
440 */
441 if (av->lvl > al || /* list sorted, so this works */
442 (av->lvl == al) & (av->weight < 0.9*r->rweight))
443 break;
444 /*
445 * Direction test using unperturbed normal
446 */
447 decodedir(uvw[2], av->ndir);
448 d = DOT(uvw[2], r->ron);
449 if (d <= 0.0) /* >= 90 degrees */
450 continue;
451 delta_r2 = 2.0 - 2.0*d; /* approx. radians^2 */
452 if (delta_r2 >= maxangle*maxangle)
453 continue;
454 /*
455 * Modified ray behind test
456 */
457 VSUB(ck0, r->rop, av->pos);
458 d = DOT(ck0, uvw[2]);
459 if (d < -minarad*ambacc-.001)
460 continue;
461 d /= av->rad[0];
462 delta_t2 = d*d;
463 if (delta_t2 >= ambacc*ambacc)
464 continue;
465 /*
466 * Elliptical radii test based on Hessian
467 */
468 decodedir(uvw[0], av->udir);
469 VCROSS(uvw[1], uvw[2], uvw[0]);
470 d = (u = DOT(ck0, uvw[0])) / av->rad[0];
471 delta_t2 += d*d;
472 d = (v = DOT(ck0, uvw[1])) / av->rad[1];
473 delta_t2 += d*d;
474 if (delta_t2 >= ambacc*ambacc)
475 continue;
476 /*
477 * Test for potential light leak
478 */
479 if (av->corral && plugaleak(r, av, uvw[2], atan2a(v,u)))
480 continue;
481 /*
482 * Extrapolate value and compute final weight (hat function)
483 */
484 if (!extambient(ct, av, r->rop, rn, uvw))
485 continue;
486 d = tfunc(maxangle, sqrt(delta_r2), 0.0) *
487 tfunc(ambacc, sqrt(delta_t2), 0.0);
488 scalecolor(ct, d);
489 addcolor(acol, ct);
490 wsum += d;
491 }
492 return(wsum);
493 }
494
495
496 static int
497 makeambient( /* make a new ambient value for storage */
498 COLOR acol,
499 RAY *r,
500 FVECT rn,
501 int al
502 )
503 {
504 AMBVAL amb;
505 FVECT uvw[3];
506 int i;
507
508 amb.weight = 1.0; /* compute weight */
509 for (i = al; i-- > 0; )
510 amb.weight *= AVGREFL;
511 if (r->rweight < 0.1*amb.weight) /* heuristic override */
512 amb.weight = 1.25*r->rweight;
513 setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
514 /* compute ambient */
515 i = doambient(acol, r, amb.weight,
516 uvw, amb.rad, amb.gpos, amb.gdir, &amb.corral);
517 scalecolor(acol, 1./AVGREFL); /* undo assumed reflectance */
518 if (i <= 0 || amb.rad[0] <= FTINY) /* no Hessian or zero radius */
519 return(i);
520 /* store value */
521 VCOPY(amb.pos, r->rop);
522 amb.ndir = encodedir(r->ron);
523 amb.udir = encodedir(uvw[0]);
524 amb.lvl = al;
525 copycolor(amb.val, acol);
526 /* insert into tree */
527 avsave(&amb); /* and save to file */
528 if (rn != r->ron) { /* texture */
529 VCOPY(uvw[2], r->ron);
530 extambient(acol, &amb, r->rop, rn, uvw);
531 }
532 return(1);
533 }
534
535
536 static int
537 extambient( /* extrapolate value at pv, nv */
538 COLOR cr,
539 AMBVAL *ap,
540 FVECT pv,
541 FVECT nv,
542 FVECT uvw[3]
543 )
544 {
545 const double min_d = 0.05;
546 const double max_d = 20.;
547 static FVECT my_uvw[3];
548 FVECT v1;
549 int i;
550 double d = 1.0; /* zeroeth order */
551
552 if (uvw == NULL) { /* need local coordinates? */
553 decodedir(my_uvw[2], ap->ndir);
554 decodedir(my_uvw[0], ap->udir);
555 VCROSS(my_uvw[1], my_uvw[2], my_uvw[0]);
556 uvw = my_uvw;
557 }
558 for (i = 3; i--; ) /* gradient due to translation */
559 d += (pv[i] - ap->pos[i]) *
560 (ap->gpos[0]*uvw[0][i] + ap->gpos[1]*uvw[1][i]);
561
562 VCROSS(v1, uvw[2], nv); /* gradient due to rotation */
563 for (i = 3; i--; )
564 d += v1[i] * (ap->gdir[0]*uvw[0][i] + ap->gdir[1]*uvw[1][i]);
565
566 if (d < min_d) /* clamp min/max scaling */
567 d = min_d;
568 else if (d > max_d)
569 d = max_d;
570 copycolor(cr, ap->val);
571 scalecolor(cr, d);
572 return(d > min_d);
573 }
574
575
576 static void
577 avinsert( /* insert ambient value in our tree */
578 AMBVAL *av
579 )
580 {
581 AMBTREE *at;
582 AMBVAL *ap;
583 AMBVAL avh;
584 FVECT ck0;
585 double s;
586 int branch;
587 int i;
588
589 if (av->rad[0] <= FTINY)
590 error(CONSISTENCY, "zero ambient radius in avinsert");
591 at = &atrunk;
592 VCOPY(ck0, thescene.cuorg);
593 s = thescene.cusize;
594 while (s*(OCTSCALE/2) > av->rad[1]*ambacc) {
595 if (at->kid == NULL)
596 if ((at->kid = newambtree()) == NULL)
597 error(SYSTEM, "out of memory in avinsert");
598 s *= 0.5;
599 branch = 0;
600 for (i = 0; i < 3; i++)
601 if (av->pos[i] > ck0[i] + s) {
602 ck0[i] += s;
603 branch |= 1 << i;
604 }
605 at = at->kid + branch;
606 }
607 avh.next = at->alist; /* order by increasing level */
608 for (ap = &avh; ap->next != NULL; ap = ap->next)
609 if ( ap->next->lvl > av->lvl ||
610 (ap->next->lvl == av->lvl) &
611 (ap->next->weight <= av->weight) )
612 break;
613 av->next = ap->next;
614 ap->next = (AMBVAL*)av;
615 at->alist = avh.next;
616 }
617
618
619 static void
620 initambfile( /* initialize ambient file */
621 int cre8
622 )
623 {
624 extern char *progname, *octname;
625 static char *mybuf = NULL;
626
627 #ifdef F_SETLKW
628 aflock(cre8 ? F_WRLCK : F_RDLCK);
629 #endif
630 SET_FILE_BINARY(ambfp);
631 if (mybuf == NULL)
632 mybuf = (char *)bmalloc(BUFSIZ+8);
633 setbuf(ambfp, mybuf);
634 if (cre8) { /* new file */
635 newheader("RADIANCE", ambfp);
636 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
637 progname, colval(ambval,RED),
638 colval(ambval,GRN), colval(ambval,BLU),
639 ambvwt, ambounce, ambacc);
640 fprintf(ambfp, "-ad %d -as %d -ar %d ",
641 ambdiv, ambssamp, ambres);
642 fprintf(ambfp, "-dr %d -ds %g -dt %g -dc %g ", directrelay,
643 srcsizerat, shadthresh, shadcert);
644 fprintf(ambfp, "-ss %g -st %g -lr %d -lw %g ", specjitter,
645 specthresh, maxdepth, minweight);
646 if (octname != NULL)
647 fputs(octname, ambfp);
648 fputc('\n', ambfp);
649 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
650 fputnow(ambfp);
651 fputformat(AMBFMT, ambfp);
652 fputc('\n', ambfp);
653 putambmagic(ambfp);
654 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
655 error(USER, "bad ambient file");
656 }
657
658
659 static void
660 avsave( /* insert and save an ambient value */
661 AMBVAL *av
662 )
663 {
664 avstore(av);
665 if (ambfp == NULL)
666 return;
667 if (writambval(av, ambfp) < 0)
668 goto writerr;
669 if (++nunflshed >= AMBFLUSH)
670 if (ambsync() == EOF)
671 goto writerr;
672 return;
673 writerr:
674 error(SYSTEM, "error writing to ambient file");
675 }
676
677
678 static AMBVAL *
679 avstore( /* allocate memory and save aval */
680 AMBVAL *aval
681 )
682 {
683 AMBVAL *av;
684 double d;
685
686 if ((av = newambval()) == NULL)
687 error(SYSTEM, "out of memory in avstore");
688 *av = *aval;
689 av->next = NULL;
690 nambvals++;
691 d = bright(av->val);
692 if (d > FTINY) { /* add to log sum for averaging */
693 avsum += log(d);
694 navsum++;
695 }
696 avinsert(av); /* insert in our cache tree */
697 return(av);
698 }
699
700
701 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
702
703 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
704
705
706 static AMBTREE *
707 newambtree(void) /* allocate 8 ambient tree structs */
708 {
709 AMBTREE *atp, *upperlim;
710
711 if (atfreelist == NULL) { /* get more nodes */
712 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
713 if (atfreelist == NULL)
714 return(NULL);
715 /* link new free list */
716 upperlim = atfreelist + 8*(ATALLOCSZ-1);
717 for (atp = atfreelist; atp < upperlim; atp += 8)
718 atp->kid = atp + 8;
719 atp->kid = NULL;
720 }
721 atp = atfreelist;
722 atfreelist = atp->kid;
723 memset(atp, 0, 8*sizeof(AMBTREE));
724 return(atp);
725 }
726
727
728 static void
729 freeambtree( /* free 8 ambient tree structs */
730 AMBTREE *atp
731 )
732 {
733 atp->kid = atfreelist;
734 atfreelist = atp;
735 }
736
737
738 static void
739 unloadatree( /* unload an ambient value tree */
740 AMBTREE *at,
741 unloadtf_t *f
742 )
743 {
744 AMBVAL *av;
745 int i;
746 /* transfer values at this node */
747 for (av = at->alist; av != NULL; av = at->alist) {
748 at->alist = av->next;
749 av->next = NULL;
750 (*f)(av);
751 }
752 if (at->kid == NULL)
753 return;
754 for (i = 0; i < 8; i++) /* transfer and free children */
755 unloadatree(at->kid+i, f);
756 freeambtree(at->kid);
757 at->kid = NULL;
758 }
759
760
761 static void
762 avfree(AMBVAL *av)
763 {
764 free(av);
765 }
766
767
768 static void
769 sortambvals(void) /* resort ambient values */
770 {
771 AMBTREE oldatrunk = atrunk;
772
773 atrunk.alist = NULL;
774 atrunk.kid = NULL;
775 unloadatree(&oldatrunk, avinsert);
776 }
777
778
779 #ifdef F_SETLKW
780
781 static void
782 aflock( /* lock/unlock ambient file */
783 int typ
784 )
785 {
786 static struct flock fls; /* static so initialized to zeroes */
787
788 if (typ == fls.l_type) /* already called? */
789 return;
790
791 fls.l_type = typ;
792 do
793 if (fcntl(fileno(ambfp), F_SETLKW, &fls) != -1)
794 return;
795 while (errno == EINTR);
796
797 error(SYSTEM, "cannot (un)lock ambient file");
798 }
799
800
801 int
802 ambsync(void) /* synchronize ambient file */
803 {
804 long flen;
805 AMBVAL avs;
806 int n;
807
808 if (ambfp == NULL) /* no ambient file? */
809 return(0);
810 /* gain appropriate access */
811 aflock(nunflshed ? F_WRLCK : F_RDLCK);
812 /* see if file has grown */
813 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
814 goto seekerr;
815 if ((n = flen - lastpos) > 0) { /* file has grown */
816 if (ambinp == NULL) { /* get new file pointer */
817 ambinp = fopen(ambfile, "rb");
818 if (ambinp == NULL)
819 error(SYSTEM, "fopen failed in ambsync");
820 }
821 if (fseek(ambinp, lastpos, SEEK_SET) < 0)
822 goto seekerr;
823 while (n >= AMBVALSIZ) { /* load contributed values */
824 if (!readambval(&avs, ambinp)) {
825 sprintf(errmsg,
826 "ambient file \"%s\" corrupted near character %ld",
827 ambfile, flen - n);
828 error(WARNING, errmsg);
829 break;
830 }
831 avstore(&avs);
832 n -= AMBVALSIZ;
833 }
834 lastpos = flen - n; /* check alignment */
835 if (n && lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
836 goto seekerr;
837 }
838 n = fflush(ambfp); /* calls write() at last */
839 lastpos += (long)nunflshed*AMBVALSIZ;
840 aflock(F_UNLCK); /* release file */
841 nunflshed = 0;
842 return(n);
843 seekerr:
844 error(SYSTEM, "seek failed in ambsync");
845 return(EOF); /* pro forma return */
846 }
847
848 #else /* ! F_SETLKW */
849
850 int
851 ambsync(void) /* flush ambient file */
852 {
853 if (ambfp == NULL)
854 return(0);
855 nunflshed = 0;
856 return(fflush(ambfp));
857 }
858
859 #endif /* ! F_SETLKW */