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root/radiance/ray/src/rt/ambient.c
Revision: 2.122
Committed: Wed Jan 31 04:03:03 2024 UTC (3 months, 2 weeks ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.121: +4 -3 lines
Log Message:
fix: improvement to last fix for ambient file opening race condition

File Contents

# Content
1 static const char RCSid[] = "$Id: ambient.c,v 2.121 2024/01/29 19:24:00 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 AVSIZE (sizeof(AMBVAL)-sizeof(SCOLOR)+sizeof(COLORV)*NCSAMP)
48 #define newambval() (AMBVAL *)malloc(AVSIZE)
49
50 #define tfunc(x0, x, x1) (((x)-(x0))/((x1)-(x0)))
51
52 static void initambfile(int cre8);
53 static void avsave(AMBVAL *av);
54 static AMBVAL *avstore(AMBVAL *aval);
55 static AMBTREE *newambtree(void);
56 static void freeambtree(AMBTREE *atp);
57
58 typedef void unloadtf_t(AMBVAL *);
59 static unloadtf_t avinsert;
60 static unloadtf_t avfree;
61 static void unloadatree(AMBTREE *at, unloadtf_t *f);
62
63 static void sortambvals(void);
64
65 static int plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang);
66 static double sumambient(SCOLOR acol, RAY *r, FVECT rn, int al,
67 AMBTREE *at, FVECT c0, double s);
68 static int makeambient(SCOLOR acol, RAY *r, FVECT rn, int al);
69 static int extambient(SCOLOR cr, AMBVAL *ap, FVECT pv, FVECT nv,
70 FVECT uvw[3]);
71
72 #ifdef F_SETLKW
73 static void aflock(int typ);
74 #endif
75
76
77 void
78 setambres( /* set ambient resolution */
79 int ar
80 )
81 {
82 ambres = ar < 0 ? 0 : ar; /* may be done already */
83 /* set min & max radii */
84 if (ar <= 0) {
85 minarad = 0;
86 maxarad = thescene.cusize*0.2;
87 } else {
88 minarad = thescene.cusize / ar;
89 maxarad = 64.0 * minarad; /* heuristic */
90 if (maxarad > thescene.cusize*0.2)
91 maxarad = thescene.cusize*0.2;
92 }
93 if (minarad <= FTINY)
94 minarad = 10.0*FTINY;
95 if (maxarad <= minarad)
96 maxarad = 64.0 * minarad;
97 }
98
99
100 void
101 setambacc( /* set ambient accuracy */
102 double newa
103 )
104 {
105 static double olda; /* remember previous setting here */
106
107 newa *= (newa > 0);
108 if (fabs(newa - olda) >= .05*(newa + olda)) {
109 ambacc = newa;
110 if (ambacc > FTINY && nambvals > 0)
111 sortambvals(); /* rebuild tree */
112 }
113 }
114
115
116 void
117 setambient(void) /* initialize calculation */
118 {
119 int readonly = 0;
120 long flen;
121 AMBVAL amb;
122 /* make sure we're fresh */
123 ambdone();
124 /* init ambient limits */
125 setambres(ambres);
126 setambacc(ambacc);
127 if (ambfile == NULL || !ambfile[0])
128 return;
129 if (ambacc <= FTINY) {
130 sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
131 ambfile);
132 error(WARNING, errmsg);
133 return;
134 }
135 /* open ambient file */
136 if ((ambfp = fopen(ambfile, "r+")) == NULL)
137 readonly = (ambfp = fopen(ambfile, "r")) != NULL;
138 if (ambfp != NULL) {
139 initambfile(0); /* file exists */
140 lastpos = ftell(ambfp);
141 while (readambval(&amb, ambfp))
142 avstore(&amb);
143 nambshare = nambvals; /* share loaded values */
144 if (readonly) {
145 sprintf(errmsg,
146 "loaded %u values from read-only ambient file",
147 nambvals);
148 error(WARNING, errmsg);
149 fclose(ambfp); /* close file so no writes */
150 ambfp = NULL;
151 return; /* avoid ambsync() */
152 }
153 /* align file pointer */
154 lastpos += (long)nambvals*AMBVALSIZ;
155 flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
156 if (flen != lastpos) {
157 sprintf(errmsg,
158 "ignoring last %ld values in ambient file (corrupted)",
159 (flen - lastpos)/AMBVALSIZ);
160 error(WARNING, errmsg);
161 fseek(ambfp, lastpos, SEEK_SET);
162 ftruncate(fileno(ambfp), (off_t)lastpos);
163 }
164 } else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
165 initambfile(1); /* else create new file */
166 fflush(ambfp);
167 lastpos = ftell(ambfp);
168 } else {
169 sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
170 error(SYSTEM, errmsg);
171 }
172 #ifdef F_SETLKW
173 aflock(F_UNLCK); /* release file */
174 #endif
175 }
176
177
178 void
179 ambdone(void) /* close ambient file and free memory */
180 {
181 if (ambfp != NULL) { /* close ambient file */
182 ambsync();
183 fclose(ambfp);
184 ambfp = NULL;
185 if (ambinp != NULL) {
186 fclose(ambinp);
187 ambinp = NULL;
188 }
189 lastpos = -1;
190 }
191 /* free ambient tree */
192 unloadatree(&atrunk, avfree);
193 /* reset state variables */
194 avsum = 0.;
195 navsum = 0;
196 nambvals = 0;
197 nambshare = 0;
198 }
199
200
201 void
202 ambnotify( /* record new modifier */
203 OBJECT obj
204 )
205 {
206 static int hitlimit = 0;
207 OBJREC *o;
208 char **amblp;
209
210 if (obj == OVOID) { /* starting over */
211 ambset[0] = 0;
212 hitlimit = 0;
213 return;
214 }
215 o = objptr(obj);
216 if (hitlimit || !ismodifier(o->otype))
217 return;
218 for (amblp = amblist; *amblp != NULL; amblp++)
219 if (!strcmp(o->oname, *amblp)) {
220 if (ambset[0] >= MAXASET) {
221 error(WARNING, "too many modifiers in ambient list");
222 hitlimit++;
223 return; /* should this be fatal? */
224 }
225 insertelem(ambset, obj);
226 return;
227 }
228 }
229
230
231 void
232 multambient( /* compute ambient component & multiply by coef. */
233 SCOLOR aval,
234 RAY *r,
235 FVECT nrm
236 )
237 {
238 static double logAvgAbsorp = 1;
239 static int rdepth = 0; /* ambient recursion */
240 SCOLOR acol, caustic;
241 int i, ok;
242 double d, l;
243
244 /* PMAP: Factor in ambient from photon map, if enabled and ray is
245 * ambient. Return as all ambient components accounted for, else
246 * continue. */
247 if (ambPmap(aval, r, rdepth))
248 return;
249
250 if (logAvgAbsorp > 0) /* exclude in -aw to avoid growth */
251 logAvgAbsorp = log(1.-AVGREFL);
252
253 /* PMAP: Factor in specular-diffuse ambient (caustics) from photon
254 * map, if enabled and ray is primary, else caustic is zero. Continue
255 * with RADIANCE ambient calculation */
256 {/* XXX TEMPORARY */
257 COLOR pmc;
258 scolor_color(pmc, aval);
259 ambPmapCaustic(pmc, r, rdepth);
260 setscolor(caustic, colval(pmc,RED), colval(pmc,GRN), colval(pmc,BLU));
261 }
262 if (ambdiv <= 0) /* no ambient calculation */
263 goto dumbamb;
264 /* check number of bounces */
265 if (rdepth >= ambounce)
266 goto dumbamb;
267 /* check ambient list */
268 if (ambincl != -1 && r->ro != NULL &&
269 ambincl != inset(ambset, r->ro->omod))
270 goto dumbamb;
271
272 if (ambacc <= FTINY) { /* no ambient storage */
273 FVECT uvd[2];
274 float dgrad[2], *dgp = NULL;
275
276 if (nrm != r->ron && DOT(nrm,r->ron) < 0.9999)
277 dgp = dgrad; /* compute rotational grad. */
278 copyscolor(acol, aval);
279 rdepth++;
280 ok = doambient(acol, r, r->rweight,
281 uvd, NULL, NULL, dgp, NULL);
282 rdepth--;
283 if (!ok)
284 goto dumbamb;
285 if ((ok > 0) & (dgp != NULL)) { /* apply texture */
286 FVECT v1;
287 VCROSS(v1, r->ron, nrm);
288 d = 1.0;
289 for (i = 3; i--; )
290 d += v1[i] * (dgp[0]*uvd[0][i] + dgp[1]*uvd[1][i]);
291 if (d >= 0.05)
292 scalescolor(acol, d);
293 }
294 copyscolor(aval, acol);
295
296 /* PMAP: add in caustic */
297 saddscolor(aval, caustic);
298 return;
299 }
300 /* interpolate ambient value */
301 scolorblack(acol);
302 d = sumambient(acol, r, nrm, rdepth,
303 &atrunk, thescene.cuorg, thescene.cusize);
304
305 if (d > FTINY) {
306 scalescolor(acol, 1.0/d);
307 smultscolor(aval, acol);
308
309 /* PMAP: add in caustic */
310 saddscolor(aval, caustic);
311 return;
312 }
313
314 rdepth++; /* need to cache new value */
315 ok = makeambient(acol, r, nrm, rdepth-1);
316 rdepth--;
317
318 if (ok) {
319 smultscolor(aval, acol); /* computed new value */
320
321 /* PMAP: add in caustic */
322 saddscolor(aval, caustic);
323 return;
324 }
325
326 dumbamb: /* return global value */
327 if ((ambvwt <= 0) | (navsum == 0)) {
328 smultcolor(aval, ambval);
329
330 /* PMAP: add in caustic */
331 saddscolor(aval, caustic);
332 return;
333 }
334
335 l = bright(ambval); /* average in computations */
336 if (l > FTINY) {
337 d = (log(l)*(double)ambvwt + avsum + logAvgAbsorp*navsum) /
338 (double)(ambvwt + navsum);
339 d = exp(d) / l;
340 scalescolor(aval, d);
341 smultcolor(aval, ambval); /* apply color of ambval */
342 } else {
343 d = exp( avsum/(double)navsum + logAvgAbsorp );
344 scalescolor(aval, d); /* neutral color */
345 }
346 }
347
348
349 /* Plug a potential leak where ambient cache value is occluded */
350 static int
351 plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang)
352 {
353 const double cost70sq = 0.1169778; /* cos(70deg)^2 */
354 RAY rtst;
355 FVECT vdif;
356 double normdot, ndotd, nadotd;
357 double a, b, c, t[2];
358
359 ang += 2.*PI*(ang < 0); /* check direction flags */
360 if ( !(ap->corral>>(int)(ang*(16./PI)) & 1) )
361 return(0);
362 /*
363 * Generate test ray, targeting 20 degrees above sample point plane
364 * along surface normal from cache position. This should be high
365 * enough to miss local geometry we don't really care about.
366 */
367 VSUB(vdif, ap->pos, r->rop);
368 normdot = DOT(anorm, r->ron);
369 ndotd = DOT(vdif, r->ron);
370 nadotd = DOT(vdif, anorm);
371 a = normdot*normdot - cost70sq;
372 b = 2.0*(normdot*ndotd - nadotd*cost70sq);
373 c = ndotd*ndotd - DOT(vdif,vdif)*cost70sq;
374 if (quadratic(t, a, b, c) != 2)
375 return(1); /* should rarely happen */
376 if (t[1] <= FTINY)
377 return(0); /* should fail behind test */
378 rayorigin(&rtst, SHADOW, r, NULL);
379 VSUM(rtst.rdir, vdif, anorm, t[1]); /* further dist. > plane */
380 rtst.rmax = normalize(rtst.rdir); /* short ray test */
381 while (localhit(&rtst, &thescene)) { /* check for occluder */
382 OBJREC *m = findmaterial(rtst.ro);
383 if (m != NULL && !istransp(m->otype) && !isBSDFproxy(m) &&
384 (rtst.clipset == NULL ||
385 !inset(rtst.clipset, rtst.ro->omod)))
386 return(1); /* plug light leak */
387 VCOPY(rtst.rorg, rtst.rop); /* skip invisible surface */
388 rtst.rmax -= rtst.rot;
389 rayclear(&rtst);
390 }
391 return(0); /* seems we're OK */
392 }
393
394
395 static double
396 sumambient( /* get interpolated ambient value */
397 SCOLOR acol,
398 RAY *r,
399 FVECT rn,
400 int al,
401 AMBTREE *at,
402 FVECT c0,
403 double s
404 )
405 { /* initial limit is 10 degrees plus ambacc radians */
406 const double minangle = 10.0 * PI/180.;
407 double maxangle = minangle + ambacc;
408 double wsum = 0.0;
409 FVECT ck0;
410 int i, j;
411 AMBVAL *av;
412
413 if (at->kid != NULL) { /* sum children first */
414 s *= 0.5;
415 for (i = 0; i < 8; i++) {
416 for (j = 0; j < 3; j++) {
417 ck0[j] = c0[j];
418 if (1<<j & i)
419 ck0[j] += s;
420 if (r->rop[j] < ck0[j] - OCTSCALE*s)
421 break;
422 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
423 break;
424 }
425 if (j == 3)
426 wsum += sumambient(acol, r, rn, al,
427 at->kid+i, ck0, s);
428 }
429 /* good enough? */
430 if ((wsum >= 0.05) & (s*ambacc > minarad))
431 return(wsum);
432 }
433 /* adjust maximum angle */
434 if (at->alist != NULL && (at->alist->lvl <= al) & (r->rweight < 0.6))
435 maxangle = (maxangle - PI/2.)*pow(r->rweight,0.13) + PI/2.;
436 /* sum this node */
437 for (av = at->alist; av != NULL; av = av->next) {
438 double u, v, d, delta_r2, delta_t2;
439 SCOLOR sct;
440 FVECT uvw[3];
441 /*
442 * Ambient level test
443 */
444 if (av->lvl > al || /* list sorted, so this works */
445 (av->lvl == al) & (av->weight < 0.9*r->rweight))
446 break;
447 /*
448 * Direction test using unperturbed normal
449 */
450 decodedir(uvw[2], av->ndir);
451 d = DOT(uvw[2], r->ron);
452 if (d <= 0.0) /* >= 90 degrees */
453 continue;
454 delta_r2 = 2.0 - 2.0*d; /* approx. radians^2 */
455 if (delta_r2 >= maxangle*maxangle)
456 continue;
457 /*
458 * Modified ray behind test
459 */
460 VSUB(ck0, r->rop, av->pos);
461 d = DOT(ck0, uvw[2]);
462 if (d < -minarad*ambacc)
463 continue;
464 d /= av->rad[0];
465 delta_t2 = d*d;
466 if (delta_t2 >= ambacc*ambacc)
467 continue;
468 /*
469 * Elliptical radii test based on Hessian
470 */
471 decodedir(uvw[0], av->udir);
472 VCROSS(uvw[1], uvw[2], uvw[0]);
473 d = (u = DOT(ck0, uvw[0])) / av->rad[0];
474 delta_t2 += d*d;
475 d = (v = DOT(ck0, uvw[1])) / av->rad[1];
476 delta_t2 += d*d;
477 if (delta_t2 >= ambacc*ambacc)
478 continue;
479 /*
480 * Test for potential light leak
481 */
482 if (av->corral && plugaleak(r, av, uvw[2], atan2a(v,u)))
483 continue;
484 /*
485 * Extrapolate value and compute final weight (hat function)
486 */
487 if (!extambient(sct, av, r->rop, rn, uvw))
488 continue;
489 d = tfunc(maxangle, sqrt(delta_r2), 0.0) *
490 tfunc(ambacc, sqrt(delta_t2), 0.0);
491 scalescolor(sct, d);
492 saddscolor(acol, sct);
493 wsum += d;
494 }
495 return(wsum);
496 }
497
498
499 static int
500 makeambient( /* make a new ambient value for storage */
501 SCOLOR acol,
502 RAY *r,
503 FVECT rn,
504 int al
505 )
506 {
507 AMBVAL amb;
508 FVECT uvw[3];
509 int i;
510
511 amb.weight = 1.0; /* compute weight */
512 for (i = al; i-- > 0; )
513 amb.weight *= AVGREFL;
514 if (r->rweight < 0.1*amb.weight) /* heuristic override */
515 amb.weight = 1.25*r->rweight;
516 setscolor(acol, AVGREFL, AVGREFL, AVGREFL);
517 /* compute ambient */
518 i = doambient(acol, r, amb.weight,
519 uvw, amb.rad, amb.gpos, amb.gdir, &amb.corral);
520 scalescolor(acol, 1./AVGREFL); /* undo assumed reflectance */
521 if (i <= 0 || amb.rad[0] <= FTINY) /* no Hessian or zero radius */
522 return(i);
523 /* store value */
524 VCOPY(amb.pos, r->rop);
525 amb.ndir = encodedir(r->ron);
526 amb.udir = encodedir(uvw[0]);
527 amb.lvl = al;
528 copyscolor(amb.val, acol);
529 /* insert into tree */
530 avsave(&amb); /* and save to file */
531 if (rn != r->ron) { /* texture */
532 VCOPY(uvw[2], r->ron);
533 extambient(acol, &amb, r->rop, rn, uvw);
534 }
535 return(1);
536 }
537
538
539 static int
540 extambient( /* extrapolate value at pv, nv */
541 SCOLOR scr,
542 AMBVAL *ap,
543 FVECT pv,
544 FVECT nv,
545 FVECT uvw[3]
546 )
547 {
548 const double min_d = 0.05;
549 const double max_d = 20.;
550 static FVECT my_uvw[3];
551 FVECT v1;
552 int i;
553 double d = 1.0; /* zeroeth order */
554
555 if (uvw == NULL) { /* need local coordinates? */
556 decodedir(my_uvw[2], ap->ndir);
557 decodedir(my_uvw[0], ap->udir);
558 VCROSS(my_uvw[1], my_uvw[2], my_uvw[0]);
559 uvw = my_uvw;
560 }
561 for (i = 3; i--; ) /* gradient due to translation */
562 d += (pv[i] - ap->pos[i]) *
563 (ap->gpos[0]*uvw[0][i] + ap->gpos[1]*uvw[1][i]);
564
565 VCROSS(v1, uvw[2], nv); /* gradient due to rotation */
566 for (i = 3; i--; )
567 d += v1[i] * (ap->gdir[0]*uvw[0][i] + ap->gdir[1]*uvw[1][i]);
568
569 if (d < min_d) /* clamp min/max scaling */
570 d = min_d;
571 else if (d > max_d)
572 d = max_d;
573 copyscolor(scr, ap->val);
574 scalescolor(scr, d);
575 return(d > min_d);
576 }
577
578
579 static void
580 avinsert( /* insert ambient value in our tree */
581 AMBVAL *av
582 )
583 {
584 AMBTREE *at;
585 AMBVAL *ap;
586 AMBVAL avh;
587 FVECT ck0;
588 double s;
589 int branch;
590 int i;
591
592 if (av->rad[0] <= FTINY)
593 error(CONSISTENCY, "zero ambient radius in avinsert");
594 at = &atrunk;
595 VCOPY(ck0, thescene.cuorg);
596 s = thescene.cusize;
597 while (s*(OCTSCALE/2) > av->rad[1]*ambacc) {
598 if (at->kid == NULL)
599 if ((at->kid = newambtree()) == NULL)
600 error(SYSTEM, "out of memory in avinsert");
601 s *= 0.5;
602 branch = 0;
603 for (i = 0; i < 3; i++)
604 if (av->pos[i] > ck0[i] + s) {
605 ck0[i] += s;
606 branch |= 1 << i;
607 }
608 at = at->kid + branch;
609 }
610 avh.next = at->alist; /* order by increasing level */
611 for (ap = &avh; ap->next != NULL; ap = ap->next)
612 if ( ap->next->lvl > av->lvl ||
613 (ap->next->lvl == av->lvl) &
614 (ap->next->weight <= av->weight) )
615 break;
616 av->next = ap->next;
617 ap->next = (AMBVAL*)av;
618 at->alist = avh.next;
619 }
620
621
622 static void
623 initambfile( /* initialize ambient file */
624 int cre8
625 )
626 {
627 extern char *progname, *octname;
628 static char *mybuf = NULL;
629
630 #ifdef F_SETLKW
631 aflock(cre8 ? F_WRLCK : F_RDLCK);
632 #endif
633 SET_FILE_BINARY(ambfp);
634 if (mybuf == NULL)
635 mybuf = (char *)bmalloc(BUFSIZ+8);
636 setbuf(ambfp, mybuf);
637 retry:
638 if (cre8) { /* new file */
639 newheader("RADIANCE", ambfp);
640 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
641 progname, colval(ambval,RED),
642 colval(ambval,GRN), colval(ambval,BLU),
643 ambvwt, ambounce, ambacc);
644 fprintf(ambfp, "-ad %d -as %d -ar %d ",
645 ambdiv, ambssamp, ambres);
646 fprintf(ambfp, "-dr %d -ds %g -dt %g -dc %g ", directrelay,
647 srcsizerat, shadthresh, shadcert);
648 fprintf(ambfp, "-ss %g -st %g -lr %d -lw %g ", specjitter,
649 specthresh, maxdepth, minweight);
650 fprintf(ambfp, "-cw %g %g -cs %d ", WLPART[3], WLPART[0], NCSAMP);
651 if (octname != NULL)
652 fputs(octname, ambfp);
653 fputc('\n', ambfp); /* end of command line, not header! */
654 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
655 fputnow(ambfp);
656 AMB_CNDX = CNDX; /* use current spectral sampling */
657 AMB_WLPART = WLPART;
658 fputwlsplit(WLPART, ambfp);
659 fputncomp(NCSAMP, ambfp);
660 fputformat(AMBFMT, ambfp);
661 fputc('\n', ambfp);
662 putambmagic(ambfp);
663 } else if (getheader(ambfp, amb_headline, NULL) < 0 || !hasambmagic(ambfp)) {
664 #ifndef F_SETLKW
665 static int ntries = 3;
666 if (--ntries > 0 && ftell(ambfp) == 0) {
667 clearerr(ambfp);
668 sleep(2);
669 goto retry;
670 }
671 #endif
672 error(USER, "bad/incompatible ambient file");
673 }
674 if ((AMB_CNDX != CNDX) | (AMB_WLPART != WLPART)) {
675 if (setspectrsamp(AMB_CNDX, AMB_WLPART) < 0)
676 error(USER, "bad wavelength sampling in ambient file");
677 if (AMB_CNDX[3] == CNDX[3] && FABSEQ(AMB_WLPART[0],WLPART[0]) &&
678 FABSEQ(AMB_WLPART[3],WLPART[3])) {
679 AMB_CNDX = CNDX;
680 AMB_WLPART = WLPART; /* just the same */
681 } else
682 error(WARNING, "different ambient file wavelength sampling");
683 }
684 }
685
686
687 static void
688 avsave( /* insert and save an ambient value */
689 AMBVAL *av
690 )
691 {
692 avstore(av);
693 if (ambfp == NULL)
694 return;
695 if (writambval(av, ambfp) < 0)
696 goto writerr;
697 if (++nunflshed >= AMBFLUSH)
698 if (ambsync() == EOF)
699 goto writerr;
700 return;
701 writerr:
702 error(SYSTEM, "error writing to ambient file");
703 }
704
705
706 static AMBVAL *
707 avstore( /* allocate memory and save aval */
708 AMBVAL *aval
709 )
710 {
711 AMBVAL *av;
712 double d;
713
714 if ((av = newambval()) == NULL)
715 error(SYSTEM, "out of memory in avstore");
716 memcpy(av, aval, AVSIZE); /* AVSIZE <= sizeof(AMBVAL) */
717 av->next = NULL;
718 nambvals++;
719 d = pbright(av->val);
720 if (d > FTINY) { /* add to log sum for averaging */
721 avsum += log(d);
722 navsum++;
723 }
724 avinsert(av); /* insert in our cache tree */
725 return(av);
726 }
727
728
729 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
730
731 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
732
733
734 static AMBTREE *
735 newambtree(void) /* allocate 8 ambient tree structs */
736 {
737 AMBTREE *atp, *upperlim;
738
739 if (atfreelist == NULL) { /* get more nodes */
740 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
741 if (atfreelist == NULL)
742 return(NULL);
743 /* link new free list */
744 upperlim = atfreelist + 8*(ATALLOCSZ-1);
745 for (atp = atfreelist; atp < upperlim; atp += 8)
746 atp->kid = atp + 8;
747 atp->kid = NULL;
748 }
749 atp = atfreelist;
750 atfreelist = atp->kid;
751 memset(atp, 0, 8*sizeof(AMBTREE));
752 return(atp);
753 }
754
755
756 static void
757 freeambtree( /* free 8 ambient tree structs */
758 AMBTREE *atp
759 )
760 {
761 atp->kid = atfreelist;
762 atfreelist = atp;
763 }
764
765
766 static void
767 unloadatree( /* unload an ambient value tree */
768 AMBTREE *at,
769 unloadtf_t *f
770 )
771 {
772 AMBVAL *av;
773 int i;
774 /* transfer values at this node */
775 for (av = at->alist; av != NULL; av = at->alist) {
776 at->alist = av->next;
777 av->next = NULL;
778 (*f)(av);
779 }
780 if (at->kid == NULL)
781 return;
782 for (i = 0; i < 8; i++) /* transfer and free children */
783 unloadatree(at->kid+i, f);
784 freeambtree(at->kid);
785 at->kid = NULL;
786 }
787
788
789 static void
790 avfree(AMBVAL *av)
791 {
792 free(av);
793 }
794
795
796 static void
797 sortambvals(void) /* resort ambient values */
798 {
799 AMBTREE oldatrunk = atrunk;
800
801 atrunk.alist = NULL;
802 atrunk.kid = NULL;
803 unloadatree(&oldatrunk, avinsert);
804 }
805
806
807 #ifdef F_SETLKW
808
809 static void
810 aflock( /* lock/unlock ambient file */
811 int typ
812 )
813 {
814 static struct flock fls; /* static so initialized to zeroes */
815
816 if (typ == fls.l_type) /* already called? */
817 return;
818
819 fls.l_type = typ;
820 do
821 if (fcntl(fileno(ambfp), F_SETLKW, &fls) != -1)
822 return;
823 while (errno == EINTR);
824
825 error(SYSTEM, "cannot (un)lock ambient file");
826 }
827
828
829 int
830 ambsync(void) /* synchronize ambient file */
831 {
832 long flen;
833 AMBVAL avs;
834 int n;
835
836 if (ambfp == NULL) /* no ambient file? */
837 return(0);
838 /* gain appropriate access */
839 aflock(nunflshed ? F_WRLCK : F_RDLCK);
840 /* see if file has grown */
841 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
842 goto seekerr;
843 if ((n = flen - lastpos) > 0) { /* file has grown */
844 if (ambinp == NULL) { /* get new file pointer */
845 ambinp = fopen(ambfile, "rb");
846 if (ambinp == NULL)
847 error(SYSTEM, "fopen failed in ambsync");
848 }
849 if (fseek(ambinp, lastpos, SEEK_SET) < 0)
850 goto seekerr;
851 while (n >= AMBVALSIZ) { /* load contributed values */
852 if (!readambval(&avs, ambinp)) {
853 sprintf(errmsg,
854 "ambient file \"%s\" corrupted near character %ld",
855 ambfile, flen - n);
856 error(WARNING, errmsg);
857 break;
858 }
859 avstore(&avs);
860 n -= AMBVALSIZ;
861 }
862 lastpos = flen - n; /* check alignment */
863 if (n && lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
864 goto seekerr;
865 }
866 n = fflush(ambfp); /* calls write() at last */
867 lastpos += (long)nunflshed*AMBVALSIZ;
868 aflock(F_UNLCK); /* release file */
869 nunflshed = 0;
870 return(n);
871 seekerr:
872 error(SYSTEM, "seek failed in ambsync");
873 return(EOF); /* pro forma return */
874 }
875
876 #else /* ! F_SETLKW */
877
878 int
879 ambsync(void) /* flush ambient file */
880 {
881 if (ambfp == NULL)
882 return(0);
883 nunflshed = 0;
884 return(fflush(ambfp));
885 }
886
887 #endif /* ! F_SETLKW */