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root/radiance/ray/src/rt/pmap.c
Revision: 2.14
Committed: Tue Mar 20 19:55:33 2018 UTC (6 years, 1 month ago) by rschregle
Content type: text/plain
Branch: MAIN
Changes since 2.13: +4 -5 lines
Log Message:
Added -ae/-ai ambient exclude options to mkpmap, cleaned up opt parsing.

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: pmap.c,v 2.13 2017/08/14 21:12:10 rschregle Exp $";
3 #endif
4
5
6 /*
7 ======================================================================
8 Photon map main module
9
10 Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
11 (c) Fraunhofer Institute for Solar Energy Systems,
12 (c) Lucerne University of Applied Sciences and Arts,
13 supported by the Swiss National Science Foundation (SNSF, #147053)
14 ======================================================================
15
16 $Id: pmap.c,v 2.13 2017/08/14 21:12:10 rschregle Exp $
17 */
18
19
20 #include "pmap.h"
21 #include "pmapmat.h"
22 #include "pmapsrc.h"
23 #include "pmaprand.h"
24 #include "pmapio.h"
25 #include "pmapbias.h"
26 #include "pmapdiag.h"
27 #include "otypes.h"
28 #include <time.h>
29 #if NIX
30 #include <sys/stat.h>
31 #include <sys/mman.h>
32 #include <sys/wait.h>
33 #endif
34
35
36 void savePmaps (const PhotonMap **pmaps, int argc, char **argv)
37 {
38 unsigned t;
39
40 for (t = 0; t < NUM_PMAP_TYPES; t++) {
41 if (pmaps [t])
42 savePhotonMap(pmaps [t], pmaps [t] -> fileName, argc, argv);
43 }
44 }
45
46
47
48 static int photonParticipate (RAY *ray)
49 /* Trace photon through participating medium. Returns 1 if passed through,
50 or 0 if absorbed and $*%&ed. Analogon to rayparticipate(). */
51 {
52 int i;
53 RREAL cosTheta, cosPhi, du, dv;
54 const float cext = colorAvg(ray -> cext),
55 albedo = colorAvg(ray -> albedo);
56 FVECT u, v;
57 COLOR cvext;
58
59 /* Mean free distance until interaction with medium */
60 ray -> rmax = -log(pmapRandom(mediumState)) / cext;
61
62 while (!localhit(ray, &thescene)) {
63 setcolor(cvext, exp(-ray -> rmax * ray -> cext [0]),
64 exp(-ray -> rmax * ray -> cext [1]),
65 exp(-ray -> rmax * ray -> cext [2]));
66
67 /* Modify ray color and normalise */
68 multcolor(ray -> rcol, cvext);
69 colorNorm(ray -> rcol);
70 VCOPY(ray -> rorg, ray -> rop);
71
72 if (albedo > FTINY && ray -> rlvl > 0)
73 /* Add to volume photon map */
74 newPhoton(volumePmap, ray);
75
76 /* Absorbed? */
77 if (pmapRandom(rouletteState) > albedo)
78 return 0;
79
80 /* Colour bleeding without attenuation (?) */
81 multcolor(ray -> rcol, ray -> albedo);
82 scalecolor(ray -> rcol, 1 / albedo);
83
84 /* Scatter photon */
85 cosTheta = ray -> gecc <= FTINY ? 2 * pmapRandom(scatterState) - 1
86 : 1 / (2 * ray -> gecc) *
87 (1 + ray -> gecc * ray -> gecc -
88 (1 - ray -> gecc * ray -> gecc) /
89 (1 - ray -> gecc + 2 * ray -> gecc *
90 pmapRandom(scatterState)));
91
92 cosPhi = cos(2 * PI * pmapRandom(scatterState));
93 du = dv = sqrt(1 - cosTheta * cosTheta); /* sin(theta) */
94 du *= cosPhi;
95 dv *= sqrt(1 - cosPhi * cosPhi); /* sin(phi) */
96
97 /* Get axes u & v perpendicular to photon direction */
98 i = 0;
99 do {
100 v [0] = v [1] = v [2] = 0;
101 v [i++] = 1;
102 fcross(u, v, ray -> rdir);
103 } while (normalize(u) < FTINY);
104 fcross(v, ray -> rdir, u);
105
106 for (i = 0; i < 3; i++)
107 ray -> rdir [i] = du * u [i] + dv * v [i] +
108 cosTheta * ray -> rdir [i];
109 ray -> rlvl++;
110 ray -> rmax = -log(pmapRandom(mediumState)) / cext;
111 }
112
113 setcolor(cvext, exp(-ray -> rot * ray -> cext [0]),
114 exp(-ray -> rot * ray -> cext [1]),
115 exp(-ray -> rot * ray -> cext [2]));
116
117 /* Modify ray color and normalise */
118 multcolor(ray -> rcol, cvext);
119 colorNorm(ray -> rcol);
120
121 /* Passed through medium */
122 return 1;
123 }
124
125
126
127 void tracePhoton (RAY *ray)
128 /* Follow photon as it bounces around... */
129 {
130 long mod;
131 OBJREC *mat, *port = NULL;
132
133 if (!ray -> parent) {
134 /* !!! PHOTON PORT REJECTION SAMPLING HACK: get photon port for
135 * !!! primary ray from ray -> ro, then reset the latter to NULL so
136 * !!! as not to interfere with localhit() */
137 port = ray -> ro;
138 ray -> ro = NULL;
139 }
140
141 if (ray -> rlvl > photonMaxBounce) {
142 #ifdef PMAP_RUNAWAY_WARN
143 error(WARNING, "runaway photon!");
144 #endif
145 return;
146 }
147
148 if (colorAvg(ray -> cext) > FTINY && !photonParticipate(ray))
149 return;
150
151 if (localhit(ray, &thescene)) {
152 mod = ray -> ro -> omod;
153
154 if (port && ray -> ro != port) {
155 /* !!! PHOTON PORT REJECTION SAMPLING HACK !!!
156 * Terminate photon if emitted from port without intersecting it;
157 * this can happen when the port's partitions extend beyond its
158 * actual geometry, e.g. with polygons. Since the total flux
159 * relayed by the port is based on the (in this case) larger
160 * partition area, it is overestimated; terminating these photons
161 * constitutes rejection sampling and thereby compensates any bias
162 * incurred by the overestimated flux. */
163 #ifdef PMAP_PORTREJECT_WARN
164 sprintf(errmsg, "photon outside port %s", ray -> ro -> oname);
165 error(WARNING, errmsg);
166 #endif
167 return;
168 }
169
170 if ((ray -> clipset && inset(ray -> clipset, mod)) || mod == OVOID) {
171 /* Transfer ray if modifier is VOID or clipped within antimatta */
172 RAY tray;
173 photonRay(ray, &tray, PMAP_XFER, NULL);
174 tracePhoton(&tray);
175 }
176 else {
177 /* Scatter for modifier material */
178 mat = objptr(mod);
179 photonScatter [mat -> otype] (mat, ray);
180 }
181 }
182 }
183
184
185
186 static void preComputeGlobal (PhotonMap *pmap)
187 /* Precompute irradiance from global photons for final gathering for
188 a random subset of finalGather * pmap -> numPhotons photons, and builds
189 the photon map, discarding the original photons. */
190 /* !!! NOTE: PRECOMPUTATION WITH OOC CURRENTLY WITHOUT CACHE !!! */
191 {
192 unsigned long i, numPreComp;
193 unsigned j;
194 PhotonIdx pIdx;
195 Photon photon;
196 RAY ray;
197 PhotonMap nuPmap;
198
199 repComplete = numPreComp = finalGather * pmap -> numPhotons;
200
201 if (verbose) {
202 sprintf(errmsg,
203 "\nPrecomputing irradiance for %ld global photons\n",
204 numPreComp);
205 eputs(errmsg);
206 #if NIX
207 fflush(stderr);
208 #endif
209 }
210
211 /* Copy photon map for precomputed photons */
212 memcpy(&nuPmap, pmap, sizeof(PhotonMap));
213
214 /* Zero counters, init new heap and extents */
215 nuPmap.numPhotons = 0;
216 initPhotonHeap(&nuPmap);
217
218 for (j = 0; j < 3; j++) {
219 nuPmap.minPos [j] = FHUGE;
220 nuPmap.maxPos [j] = -FHUGE;
221 }
222
223 /* Record start time, baby */
224 repStartTime = time(NULL);
225 #ifdef SIGCONT
226 signal(SIGCONT, pmapPreCompReport);
227 #endif
228 repProgress = 0;
229
230 photonRay(NULL, &ray, PRIMARY, NULL);
231 ray.ro = NULL;
232
233 for (i = 0; i < numPreComp; i++) {
234 /* Get random photon from stratified distribution in source heap to
235 * avoid duplicates and clustering */
236 pIdx = firstPhoton(pmap) +
237 (unsigned long)((i + pmapRandom(pmap -> randState)) /
238 finalGather);
239 getPhoton(pmap, pIdx, &photon);
240
241 /* Init dummy photon ray with intersection at photon position */
242 VCOPY(ray.rop, photon.pos);
243 for (j = 0; j < 3; j++)
244 ray.ron [j] = photon.norm [j] / 127.0;
245
246 /* Get density estimate at photon position */
247 photonDensity(pmap, &ray, ray.rcol);
248
249 /* Append photon to new heap from ray */
250 newPhoton(&nuPmap, &ray);
251
252 /* Update progress */
253 repProgress++;
254
255 if (photonRepTime > 0 && time(NULL) >= repLastTime + photonRepTime)
256 pmapPreCompReport();
257 #ifdef SIGCONT
258 else signal(SIGCONT, pmapPreCompReport);
259 #endif
260 }
261
262 /* Flush heap */
263 flushPhotonHeap(&nuPmap);
264
265 #ifdef SIGCONT
266 signal(SIGCONT, SIG_DFL);
267 #endif
268
269 /* Trash original pmap, replace with precomputed one */
270 deletePhotons(pmap);
271 memcpy(pmap, &nuPmap, sizeof(PhotonMap));
272
273 if (verbose) {
274 eputs("\nRebuilding precomputed photon map\n");
275 #if NIX
276 fflush(stderr);
277 #endif
278 }
279
280 /* Rebuild underlying data structure, destroying heap */
281 buildPhotonMap(pmap, NULL, NULL, 1);
282 }
283
284
285
286 typedef struct {
287 unsigned long numPhotons [NUM_PMAP_TYPES],
288 numEmitted, numComplete;
289 } PhotonCnt;
290
291
292
293 void distribPhotons (PhotonMap **pmaps, unsigned numProc)
294 {
295 EmissionMap emap;
296 char errmsg2 [128], shmFname [PMAP_TMPFNLEN];
297 unsigned t, srcIdx, proc;
298 double totalFlux = 0;
299 int shmFile, stat, pid;
300 PhotonMap *pm;
301 PhotonCnt *photonCnt;
302
303 for (t = 0; t < NUM_PMAP_TYPES && !pmaps [t]; t++);
304
305 if (t >= NUM_PMAP_TYPES)
306 error(USER, "no photon maps defined in distribPhotons");
307
308 if (!nsources)
309 error(USER, "no light sources in distribPhotons");
310
311 /* ===================================================================
312 * INITIALISATION - Set up emission and scattering funcs
313 * =================================================================== */
314 emap.samples = NULL;
315 emap.maxPartitions = MAXSPART;
316 emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1);
317 if (!emap.partitions)
318 error(INTERNAL, "can't allocate source partitions in distribPhotons");
319
320 /* Initialise all defined photon maps */
321 for (t = 0; t < NUM_PMAP_TYPES; t++)
322 if (pmaps [t]) {
323 initPhotonMap(pmaps [t], t);
324 /* Open photon heapfile */
325 initPhotonHeap(pmaps [t]);
326 /* Per-subprocess target count */
327 pmaps [t] -> distribTarget /= numProc;
328
329 if (!pmaps [t] -> distribTarget)
330 error(INTERNAL, "no photons to distribute in distribPhotons");
331 }
332
333 initPhotonEmissionFuncs();
334 initPhotonScatterFuncs();
335
336 /* Get photon ports from modifier list */
337 getPhotonPorts(photonPortList);
338
339 /* Get photon sensor modifiers */
340 getPhotonSensors(photonSensorList);
341
342 #if NIX
343 /* Set up shared mem for photon counters (zeroed by ftruncate) */
344 strcpy(shmFname, PMAP_TMPFNAME);
345 shmFile = mkstemp(shmFname);
346
347 if (shmFile < 0 || ftruncate(shmFile, sizeof(*photonCnt)) < 0)
348 error(SYSTEM, "failed shared mem init in distribPhotons");
349
350 photonCnt = mmap(NULL, sizeof(*photonCnt), PROT_READ | PROT_WRITE,
351 MAP_SHARED, shmFile, 0);
352
353 if (photonCnt == MAP_FAILED)
354 error(SYSTEM, "failed mapping shared memory in distribPhotons");
355 #else
356 /* Allocate photon counters statically on Windoze */
357 if (!(photonCnt = malloc(sizeof(PhotonCnt))))
358 error(SYSTEM, "failed trivial malloc in distribPhotons");
359 photonCnt -> numEmitted = photonCnt -> numComplete = 0;
360 #endif /* NIX */
361
362 if (verbose) {
363 sprintf(errmsg, "\nIntegrating flux from %d sources", nsources);
364
365 if (photonPorts) {
366 sprintf(errmsg2, " via %d ports", numPhotonPorts);
367 strcat(errmsg, errmsg2);
368 }
369
370 strcat(errmsg, "\n");
371 eputs(errmsg);
372 }
373
374 /* ===================================================================
375 * FLUX INTEGRATION - Get total photon flux from light sources
376 * =================================================================== */
377 for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
378 unsigned portCnt = 0;
379 emap.src = source + srcIdx;
380
381 do { /* Need at least one iteration if no ports! */
382 emap.port = emap.src -> sflags & SDISTANT ? photonPorts + portCnt
383 : NULL;
384 photonPartition [emap.src -> so -> otype] (&emap);
385
386 if (verbose) {
387 sprintf(errmsg, "\tIntegrating flux from source %s ",
388 source [srcIdx].so -> oname);
389
390 if (emap.port) {
391 sprintf(errmsg2, "via port %s ",
392 photonPorts [portCnt].so -> oname);
393 strcat(errmsg, errmsg2);
394 }
395
396 sprintf(errmsg2, "(%lu partitions)\n", emap.numPartitions);
397 strcat(errmsg, errmsg2);
398 eputs(errmsg);
399 #if NIX
400 fflush(stderr);
401 #endif
402 }
403
404 for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions;
405 emap.partitionCnt++) {
406 initPhotonEmission(&emap, pdfSamples);
407 totalFlux += colorAvg(emap.partFlux);
408 }
409
410 portCnt++;
411 } while (portCnt < numPhotonPorts);
412 }
413
414 if (totalFlux < FTINY)
415 error(USER, "zero flux from light sources");
416
417 /* Record start time for progress reports */
418 repStartTime = time(NULL);
419
420 if (verbose) {
421 sprintf(errmsg, "\nPhoton distribution @ %d procs\n", numProc);
422 eputs(errmsg);
423 }
424
425 /* MAIN LOOP */
426 for (proc = 0; proc < numProc; proc++) {
427 #if NIX
428 if (!(pid = fork())) {
429 /* SUBPROCESS ENTERS HERE; open and mmapped files inherited */
430 #else
431 if (1) {
432 /* No subprocess under Windoze */
433 #endif
434 /* Local photon counters for this subprocess */
435 unsigned passCnt = 0, prePassCnt = 0;
436 unsigned long lastNumPhotons [NUM_PMAP_TYPES];
437 unsigned long localNumEmitted = 0; /* Num photons emitted by this
438 subprocess alone */
439
440 /* Seed RNGs from PID for decorellated photon distribution */
441 pmapSeed(randSeed + proc, partState);
442 pmapSeed(randSeed + (proc + 1) % numProc, emitState);
443 pmapSeed(randSeed + (proc + 2) % numProc, cntState);
444 pmapSeed(randSeed + (proc + 3) % numProc, mediumState);
445 pmapSeed(randSeed + (proc + 4) % numProc, scatterState);
446 pmapSeed(randSeed + (proc + 5) % numProc, rouletteState);
447
448 for (t = 0; t < NUM_PMAP_TYPES; t++)
449 lastNumPhotons [t] = 0;
450
451 /* =============================================================
452 * 2-PASS PHOTON DISTRIBUTION
453 * Pass 1 (pre): emit fraction of target photon count
454 * Pass 2 (main): based on outcome of pass 1, estimate remaining
455 * number of photons to emit to approximate target
456 * count
457 * ============================================================= */
458 do {
459 double numEmit;
460
461 if (!passCnt) {
462 /* INIT PASS 1 */
463 /* Skip if no photons contributed after sufficient
464 * iterations; make it clear to user which photon maps are
465 * missing so (s)he can check geometry and materials */
466 if (++prePassCnt > maxPreDistrib) {
467 sprintf(errmsg, "proc %d: too many prepasses", proc);
468
469 for (t = 0; t < NUM_PMAP_TYPES; t++)
470 if (pmaps [t] && !pmaps [t] -> numPhotons) {
471 sprintf(errmsg2, ", no %s photons stored",
472 pmapName [t]);
473 strcat(errmsg, errmsg2);
474 }
475
476 error(USER, errmsg);
477 break;
478 }
479
480 /* Num to emit is fraction of minimum target count */
481 numEmit = FHUGE;
482
483 for (t = 0; t < NUM_PMAP_TYPES; t++)
484 if (pmaps [t])
485 numEmit = min(pmaps [t] -> distribTarget, numEmit);
486
487 numEmit *= preDistrib;
488 }
489 else {
490 /* INIT PASS 2 */
491 /* Based on the outcome of the predistribution we can now
492 * estimate how many more photons we have to emit for each
493 * photon map to meet its respective target count. This
494 * value is clamped to 0 in case the target has already been
495 * exceeded in the pass 1. */
496 double maxDistribRatio = 0;
497
498 /* Set the distribution ratio for each map; this indicates
499 * how many photons of each respective type are stored per
500 * emitted photon, and is used as probability for storing a
501 * photon by newPhoton(). Since this biases the photon
502 * density, newPhoton() promotes the flux of stored photons
503 * to compensate. */
504 for (t = 0; t < NUM_PMAP_TYPES; t++)
505 if ((pm = pmaps [t])) {
506 pm -> distribRatio = (double)pm -> distribTarget /
507 pm -> numPhotons - 1;
508
509 /* Check if photon map "overflowed", i.e. exceeded its
510 * target count in the prepass; correcting the photon
511 * flux via the distribution ratio is no longer
512 * possible, as no more photons of this type will be
513 * stored, so notify the user rather than deliver
514 * incorrect results. In future we should handle this
515 * more intelligently by using the photonFlux in each
516 * photon map to individually correct the flux after
517 * distribution. */
518 if (pm -> distribRatio <= FTINY) {
519 sprintf(errmsg, "%s photon map overflow in "
520 "prepass, reduce -apD", pmapName [t]);
521 error(INTERNAL, errmsg);
522 }
523
524 maxDistribRatio = max(pm -> distribRatio,
525 maxDistribRatio);
526 }
527
528 /* Normalise distribution ratios and calculate number of
529 * photons to emit in main pass */
530 for (t = 0; t < NUM_PMAP_TYPES; t++)
531 if ((pm = pmaps [t]))
532 pm -> distribRatio /= maxDistribRatio;
533
534 if ((numEmit = localNumEmitted * maxDistribRatio) < FTINY)
535 /* No photons left to distribute in main pass */
536 break;
537 }
538
539 /* Update shared completion counter for progreport by parent */
540 photonCnt -> numComplete += numEmit;
541
542 /* PHOTON DISTRIBUTION LOOP */
543 for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
544 unsigned portCnt = 0;
545 emap.src = source + srcIdx;
546
547 do { /* Need at least one iteration if no ports! */
548 emap.port = emap.src -> sflags & SDISTANT
549 ? photonPorts + portCnt : NULL;
550 photonPartition [emap.src -> so -> otype] (&emap);
551
552 if (verbose && !proc) {
553 /* Output from subproc 0 only to avoid race condition
554 * on console I/O */
555 if (!passCnt)
556 sprintf(errmsg, "\tPREPASS %d on source %s ",
557 prePassCnt, source [srcIdx].so -> oname);
558 else
559 sprintf(errmsg, "\tMAIN PASS on source %s ",
560 source [srcIdx].so -> oname);
561
562 if (emap.port) {
563 sprintf(errmsg2, "via port %s ",
564 photonPorts [portCnt].so -> oname);
565 strcat(errmsg, errmsg2);
566 }
567
568 sprintf(errmsg2, "(%lu partitions)\n",
569 emap.numPartitions);
570 strcat(errmsg, errmsg2);
571 eputs(errmsg);
572 #if NIX
573 fflush(stderr);
574 #endif
575 }
576
577 for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions;
578 emap.partitionCnt++) {
579 double partNumEmit;
580 unsigned long partEmitCnt;
581
582 /* Get photon origin within current source partishunn
583 * and build emission map */
584 photonOrigin [emap.src -> so -> otype] (&emap);
585 initPhotonEmission(&emap, pdfSamples);
586
587 /* Number of photons to emit from ziss partishunn --
588 * proportional to flux; photon ray weight and scalar
589 * flux are uniform (latter only varying in RGB). */
590 partNumEmit = numEmit * colorAvg(emap.partFlux) /
591 totalFlux;
592 partEmitCnt = (unsigned long)partNumEmit;
593
594 /* Probabilistically account for fractional photons */
595 if (pmapRandom(cntState) < partNumEmit - partEmitCnt)
596 partEmitCnt++;
597
598 /* Update local and shared (global) emission counter */
599 photonCnt -> numEmitted += partEmitCnt;
600 localNumEmitted += partEmitCnt;
601
602 /* Integer counter avoids FP rounding errors during
603 * iteration */
604 while (partEmitCnt--) {
605 RAY photonRay;
606
607 /* Emit photon based on PDF and trace through scene
608 * until absorbed/leaked */
609 emitPhoton(&emap, &photonRay);
610 #if 1
611 if (emap.port)
612 /* !!! PHOTON PORT REJECTION SAMPLING HACK: set
613 * !!! photon port as fake hit object for
614 * !!! primary ray to check for intersection in
615 * !!! tracePhoton() */
616 photonRay.ro = emap.port -> so;
617 #endif
618 tracePhoton(&photonRay);
619 }
620
621 /* Update shared global photon count for each pmap */
622 for (t = 0; t < NUM_PMAP_TYPES; t++)
623 if (pmaps [t]) {
624 photonCnt -> numPhotons [t] +=
625 pmaps [t] -> numPhotons - lastNumPhotons [t];
626 lastNumPhotons [t] = pmaps [t] -> numPhotons;
627 }
628 #if !NIX
629 /* Synchronous progress report on Windoze */
630 if (!proc && photonRepTime > 0 &&
631 time(NULL) >= repLastTime + photonRepTime) {
632 repEmitted = repProgress = photonCnt -> numEmitted;
633 repComplete = photonCnt -> numComplete;
634 pmapDistribReport();
635 }
636 #endif
637 }
638
639 portCnt++;
640 } while (portCnt < numPhotonPorts);
641 }
642
643 for (t = 0; t < NUM_PMAP_TYPES; t++)
644 if (pmaps [t] && !pmaps [t] -> numPhotons) {
645 /* Double preDistrib in case a photon map is empty and
646 * redo pass 1 --> possibility of infinite loop for
647 * pathological scenes (e.g. absorbing materials) */
648 preDistrib *= 2;
649 break;
650 }
651
652 if (t >= NUM_PMAP_TYPES)
653 /* No empty photon maps found; now do pass 2 */
654 passCnt++;
655 } while (passCnt < 2);
656
657 /* Flush heap buffa for every pmap one final time;
658 * avoids potential data corruption! */
659 for (t = 0; t < NUM_PMAP_TYPES; t++)
660 if (pmaps [t]) {
661 flushPhotonHeap(pmaps [t]);
662 /* Heap file closed automatically on exit
663 fclose(pmaps [t] -> heap); */
664 #ifdef DEBUG_PMAP
665 sprintf(errmsg, "Proc %d: total %ld photons\n", proc,
666 pmaps [t] -> numPhotons);
667 eputs(errmsg);
668 #endif
669 }
670 #if NIX
671 /* Terminate subprocess */
672 exit(0);
673 #endif
674 }
675 else if (pid < 0)
676 error(SYSTEM, "failed to fork subprocess in distribPhotons");
677 }
678
679 #if NIX
680 /* PARENT PROCESS CONTINUES HERE */
681 #ifdef SIGCONT
682 /* Enable progress report signal handler */
683 signal(SIGCONT, pmapDistribReport);
684 #endif
685 /* Wait for subprocesses complete while reporting progress */
686 proc = numProc;
687 while (proc) {
688 while (waitpid(-1, &stat, WNOHANG) > 0) {
689 /* Subprocess exited; check status */
690 if (!WIFEXITED(stat) || WEXITSTATUS(stat))
691 error(USER, "failed photon distribution");
692
693 --proc;
694 }
695
696 /* Nod off for a bit and update progress */
697 sleep(1);
698
699 /* Asynchronous progress report from shared subprocess counters */
700 repEmitted = repProgress = photonCnt -> numEmitted;
701 repComplete = photonCnt -> numComplete;
702
703 repProgress = repComplete = 0;
704 for (t = 0; t < NUM_PMAP_TYPES; t++)
705 if ((pm = pmaps [t])) {
706 /* Get global photon count from shmem updated by subprocs */
707 repProgress += pm -> numPhotons = photonCnt -> numPhotons [t];
708 repComplete += pm -> distribTarget;
709 }
710 repComplete *= numProc;
711
712 if (photonRepTime > 0 && time(NULL) >= repLastTime + photonRepTime)
713 pmapDistribReport();
714 #ifdef SIGCONT
715 else signal(SIGCONT, pmapDistribReport);
716 #endif
717 }
718 #endif /* NIX */
719
720 /* ===================================================================
721 * POST-DISTRIBUTION - Set photon flux and build data struct for photon
722 * storage, etc.
723 * =================================================================== */
724 #ifdef SIGCONT
725 /* Reset signal handler */
726 signal(SIGCONT, SIG_DFL);
727 #endif
728 free(emap.samples);
729
730 /* Set photon flux */
731 totalFlux /= photonCnt -> numEmitted;
732 #if NIX
733 /* Photon counters no longer needed, unmap shared memory */
734 munmap(photonCnt, sizeof(*photonCnt));
735 close(shmFile);
736 unlink(shmFname);
737 #else
738 free(photonCnt);
739 #endif
740 if (verbose)
741 eputs("\n");
742
743 for (t = 0; t < NUM_PMAP_TYPES; t++)
744 if (pmaps [t]) {
745 if (verbose) {
746 sprintf(errmsg, "Building %s photon map\n", pmapName [t]);
747 eputs(errmsg);
748 #if NIX
749 fflush(stderr);
750 #endif
751 }
752
753 /* Build underlying data structure; heap is destroyed */
754 buildPhotonMap(pmaps [t], &totalFlux, NULL, numProc);
755 }
756
757 /* Precompute photon irradiance if necessary */
758 if (preCompPmap) {
759 if (verbose)
760 eputs("\n");
761 preComputeGlobal(preCompPmap);
762 }
763
764 if (verbose)
765 eputs("\n");
766 }