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Comparing ray/src/rt/pmap.c (file contents):
Revision 2.2 by greg, Tue Apr 21 19:16:51 2015 UTC vs.
Revision 2.12 by greg, Mon Sep 26 20:19:30 2016 UTC

# Line 1 | Line 1
1 + #ifndef lint
2 + static const char RCSid[] = "$Id$";
3 + #endif
4 +
5   /*
6 <   ==================================================================
6 >   ======================================================================
7     Photon map main module
8  
9     Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
10     (c) Fraunhofer Institute for Solar Energy Systems,
11 <       Lucerne University of Applied Sciences & Arts  
12 <   ==================================================================
11 >   (c) Lucerne University of Applied Sciences and Arts,
12 >       supported by the Swiss National Science Foundation (SNSF, #147053)
13 >   ======================================================================
14    
15     $Id$
16   */
# Line 22 | Line 27
27   #include "otypes.h"
28   #include <time.h>
29   #include <sys/stat.h>
30 + #include <sys/mman.h>
31 + #include <sys/wait.h>
32  
33  
34  
28 extern char *octname;
29
30 static char PmapRevision [] = "$Revision$";
31
32
33
34 /* Photon map lookup functions per type */
35 void (*pmapLookup [NUM_PMAP_TYPES])(PhotonMap*, RAY*, COLOR) = {
36   photonDensity, photonPreCompDensity, photonDensity, volumePhotonDensity,
37   photonDensity, NULL
38 };
39
40
41
42 void colorNorm (COLOR c)
43 /* Normalise colour channels to average of 1 */
44 {
45   const float avg = colorAvg(c);
46  
47   if (!avg)
48      return;
49      
50   c [0] /= avg;
51   c [1] /= avg;
52   c [2] /= avg;
53 }
54
55
56
57 void loadPmaps (PhotonMap **pmaps, const PhotonMapParams *parm)
58 {
59   unsigned t;
60   struct stat octstat, pmstat;
61   PhotonMap *pm;
62   PhotonMapType type;
63  
64   for (t = 0; t < NUM_PMAP_TYPES; t++)
65      if (setPmapParam(&pm, parm + t)) {        
66         /* Check if photon map newer than octree */
67         if (!stat(pm -> fileName, &pmstat) && !stat(octname, &octstat) &&
68             octstat.st_mtime > pmstat.st_mtime) {
69            sprintf(errmsg, "photon map in file %s may be stale",
70                    pm -> fileName);
71            error(USER, errmsg);
72         }
73        
74         /* Load photon map from file and get its type */
75         if ((type = loadPhotonMap(pm, pm -> fileName)) == PMAP_TYPE_NONE)
76            error(USER, "failed loading photon map");
77            
78         /* Assign to appropriate photon map type (deleting previously
79          * loaded photon map of same type if necessary) */
80         if (pmaps [type]) {
81            deletePhotons(pmaps [type]);
82            free(pmaps [type]);
83         }
84         pmaps [type] = pm;
85        
86         /* Check for invalid density estimate bandwidth */                            
87         if (pm -> maxGather > pm -> heapSize) {
88            error(WARNING, "adjusting density estimate bandwidth");
89            pm -> minGather = pm -> maxGather = pm -> heapSize;
90         }
91      }
92 }
93
94
95
35   void savePmaps (const PhotonMap **pmaps, int argc, char **argv)
36   {
37     unsigned t;
38    
39     for (t = 0; t < NUM_PMAP_TYPES; t++) {
40        if (pmaps [t])
41 <         savePhotonMap(pmaps [t], pmaps [t] -> fileName, t, argc, argv);
41 >         savePhotonMap(pmaps [t], pmaps [t] -> fileName, argc, argv);
42     }
43   }                  
44  
45  
107  
108 void cleanUpPmaps (PhotonMap **pmaps)
109 {
110   unsigned t;
111  
112   for (t = 0; t < NUM_PMAP_TYPES; t++) {
113      if (pmaps [t]) {
114         deletePhotons(pmaps [t]);
115         free(pmaps [t]);
116      }
117   }
118 }
119
120
46      
47   static int photonParticipate (RAY *ray)
48   /* Trace photon through participating medium. Returns 1 if passed through,
# Line 143 | Line 68 | static int photonParticipate (RAY *ray)
68        colorNorm(ray -> rcol);
69        VCOPY(ray -> rorg, ray -> rop);
70        
71 <      if (albedo > FTINY)
71 >      if (albedo > FTINY && ray -> rlvl > 0)
72           /* Add to volume photon map */
73 <         if (ray -> rlvl > 0) addPhoton(volumePmap, ray);
73 >         newPhoton(volumePmap, ray);
74          
75        /* Absorbed? */
76 <      if (pmapRandom(rouletteState) > albedo) return 0;
76 >      if (pmapRandom(rouletteState) > albedo)
77 >         return 0;
78        
79        /* Colour bleeding without attenuation (?) */
80        multcolor(ray -> rcol, ray -> albedo);
# Line 204 | Line 130 | void tracePhoton (RAY *ray)
130     OBJREC* mat;
131  
132     if (ray -> rlvl > photonMaxBounce) {
133 + #ifdef PMAP_RUNAWAY_WARN  
134        error(WARNING, "runaway photon!");
135 + #endif      
136        return;
137     }
138 <  
138 >  
139     if (colorAvg(ray -> cext) > FTINY && !photonParticipate(ray))
140        return;
141        
# Line 231 | Line 159 | void tracePhoton (RAY *ray)
159  
160  
161   static void preComputeGlobal (PhotonMap *pmap)
162 < /* Precompute irradiance from global photons for final gathering using
163 <   the first finalGather * pmap -> heapSize photons in the heap. Returns
164 <   new heap with precomputed photons. */
162 > /* Precompute irradiance from global photons for final gathering for  
163 >   a random subset of finalGather * pmap -> numPhotons photons, and builds
164 >   the photon map, discarding the original photons. */
165 > /* !!! NOTE: PRECOMPUTATION WITH OOC CURRENTLY WITHOUT CACHE !!! */  
166   {
167 <   unsigned long i, nuHeapSize;
168 <   unsigned j;
169 <   Photon *nuHeap, *p;
170 <   COLOR irrad;
171 <   RAY ray;
172 <   float nuMinPos [3], nuMaxPos [3];
167 >   unsigned long  i, numPreComp;
168 >   unsigned       j;
169 >   PhotonIdx      pIdx;
170 >   Photon         photon;
171 >   RAY            ray;
172 >   PhotonMap      nuPmap;
173  
174 <   repComplete = nuHeapSize = finalGather * pmap -> heapSize;
174 >   repComplete = numPreComp = finalGather * pmap -> numPhotons;
175    
176     if (photonRepTime) {
177 <      sprintf(errmsg,
178 <              "Precomputing irradiance for %ld global photons...\n",
250 <              nuHeapSize);
177 >      sprintf(errmsg, "Precomputing irradiance for %ld global photons...\n",
178 >              numPreComp);
179        eputs(errmsg);
180        fflush(stderr);
181     }
182    
183 <   p = nuHeap = (Photon*)malloc(nuHeapSize * sizeof(Photon));
184 <   if (!nuHeap)
185 <      error(USER, "can't allocate photon heap");
186 <      
187 <   for (j = 0; j <= 2; j++) {
188 <      nuMinPos [j] = FHUGE;
261 <      nuMaxPos [j] = -FHUGE;
262 <   }
183 >   /* Copy photon map for precomputed photons */
184 >   memcpy(&nuPmap, pmap, sizeof(PhotonMap));
185 >
186 >   /* Zero counters, init new heap and extents */  
187 >   nuPmap.numPhotons = 0;  
188 >   initPhotonHeap(&nuPmap);
189    
190 +   for (j = 0; j < 3; j++) {  
191 +      nuPmap.minPos [j] = FHUGE;
192 +      nuPmap.maxPos [j] = -FHUGE;
193 +   }
194 +
195     /* Record start time, baby */
196     repStartTime = time(NULL);
197 + #ifdef SIGCONT
198     signal(SIGCONT, pmapPreCompReport);
199 + #endif
200     repProgress = 0;
268   memcpy(nuHeap, pmap -> heap, nuHeapSize * sizeof(Photon));
201    
202 <   for (i = 0, p = nuHeap; i < nuHeapSize; i++, p++) {
203 <      ray.ro = NULL;
204 <      VCOPY(ray.rop, p -> pos);
202 >   photonRay(NULL, &ray, PRIMARY, NULL);
203 >   ray.ro = NULL;
204 >  
205 >   for (i = 0; i < numPreComp; i++) {
206 >      /* Get random photon from stratified distribution in source heap to
207 >       * avoid duplicates and clutering */
208 >      pIdx = firstPhoton(pmap) +
209 >             (unsigned long)((i + pmapRandom(pmap -> randState)) /
210 >                             finalGather);
211 >      getPhoton(pmap, pIdx, &photon);
212        
213 <      /* Update min and max positions & set ray normal */
214 <      for (j = 0; j < 3; j++) {
215 <         if (p -> pos [j] < nuMinPos [j]) nuMinPos [j] = p -> pos [j];
216 <         if (p -> pos [j] > nuMaxPos [j]) nuMaxPos [j] = p -> pos [j];
278 <         ray.ron [j] = p -> norm [j] / 127.0;
279 <      }
213 >      /* Init dummy photon ray with intersection at photon position */
214 >      VCOPY(ray.rop, photon.pos);
215 >      for (j = 0; j < 3; j++)
216 >         ray.ron [j] = photon.norm [j] / 127.0;
217        
218 <      photonDensity(pmap, &ray, irrad);
219 <      setPhotonFlux(p, irrad);
218 >      /* Get density estimate at photon position */
219 >      photonDensity(pmap, &ray, ray.rcol);
220 >                  
221 >      /* Append photon to new heap from ray */
222 >      newPhoton(&nuPmap, &ray);
223 >      
224 >      /* Update progress */
225        repProgress++;
226        
227        if (photonRepTime > 0 && time(NULL) >= repLastTime + photonRepTime)
228           pmapPreCompReport();
229 < #ifndef BSD
229 > #ifdef SIGCONT
230        else signal(SIGCONT, pmapPreCompReport);
231   #endif
232     }
233    
234 +   /* Flush heap */
235 +   flushPhotonHeap(&nuPmap);
236 +  
237 + #ifdef SIGCONT  
238     signal(SIGCONT, SIG_DFL);
239 + #endif
240    
241 <   /* Replace & rebuild heap */
242 <   free(pmap -> heap);
243 <   pmap -> heap = nuHeap;
297 <   pmap -> heapSize = pmap -> heapEnd = nuHeapSize;
298 <   VCOPY(pmap -> minPos, nuMinPos);
299 <   VCOPY(pmap -> maxPos, nuMaxPos);
241 >   /* Trash original pmap, replace with precomputed one */
242 >   deletePhotons(pmap);
243 >   memcpy(pmap, &nuPmap, sizeof(PhotonMap));
244    
245     if (photonRepTime) {
246 <      eputs("Rebuilding global photon heap...\n");
246 >      eputs("Rebuilding precomputed photon map...\n");
247        fflush(stderr);
248     }
249 <  
250 <   balancePhotons(pmap, NULL);
249 >
250 >   /* Rebuild underlying data structure, destroying heap */  
251 >   buildPhotonMap(pmap, NULL, NULL, 1);
252   }
253  
254  
255  
256 < void distribPhotons (PhotonMap **pmaps)
256 > typedef struct {
257 >   unsigned long  numPhotons [NUM_PMAP_TYPES],
258 >                  numEmitted, numComplete;
259 > } PhotonCnt;
260 >
261 >
262 >
263 > void distribPhotons (PhotonMap **pmaps, unsigned numProc)
264   {
265 <   EmissionMap emap;
266 <   char errmsg2 [128];
267 <   unsigned t, srcIdx, passCnt = 0, prePassCnt = 0;
268 <   double totalFlux = 0;
269 <   PhotonMap *pm;
265 >   EmissionMap    emap;
266 >   char           errmsg2 [128], shmFname [255];
267 >   unsigned       t, srcIdx, proc;
268 >   double         totalFlux = 0;
269 >   int            shmFile, stat, pid;
270 >   PhotonMap      *pm;
271 >   PhotonCnt      *photonCnt;
272    
273 <   for (t = 0; t < NUM_PMAP_TYPES && !photonMaps [t]; t++);
273 >   for (t = 0; t < NUM_PMAP_TYPES && !pmaps [t]; t++);
274 >  
275     if (t >= NUM_PMAP_TYPES)
276 <      error(USER, "no photon maps defined");
276 >      error(USER, "no photon maps defined in distribPhotons");
277        
278     if (!nsources)
279 <      error(USER, "no light sources");
279 >      error(USER, "no light sources in distribPhotons");
280  
281     /* ===================================================================
282      * INITIALISATION - Set up emission and scattering funcs
# Line 330 | Line 285 | void distribPhotons (PhotonMap **pmaps)
285     emap.maxPartitions = MAXSPART;
286     emap.partitions = (unsigned char*)malloc(emap.maxPartitions >> 1);
287     if (!emap.partitions)
288 <      error(INTERNAL, "can't allocate source partitions");
288 >      error(INTERNAL, "can't allocate source partitions in distribPhotons");
289        
290     /* Initialise all defined photon maps */
291     for (t = 0; t < NUM_PMAP_TYPES; t++)
292 <      initPhotonMap(photonMaps [t], t);
292 >      if (pmaps [t]) {
293 >         initPhotonMap(pmaps [t], t);
294 >         /* Open photon heapfile */
295 >         initPhotonHeap(pmaps [t]);
296 >         /* Per-subprocess target count */
297 >         pmaps [t] -> distribTarget /= numProc;
298 >      }
299  
300     initPhotonEmissionFuncs();
301     initPhotonScatterFuncs();
# Line 346 | Line 307 | void distribPhotons (PhotonMap **pmaps)
307     /* Get photon sensor modifiers */
308     getPhotonSensors(photonSensorList);
309    
310 <   /* Seed RNGs for photon distribution */
311 <   pmapSeed(randSeed, partState);
312 <   pmapSeed(randSeed, emitState);
313 <   pmapSeed(randSeed, cntState);
314 <   pmapSeed(randSeed, mediumState);
315 <   pmapSeed(randSeed, scatterState);
316 <   pmapSeed(randSeed, rouletteState);
317 <  
310 >   /* Set up shared mem for photon counters (zeroed by ftruncate) */
311 > #if 0  
312 >   snprintf(shmFname, 255, PMAP_SHMFNAME, getpid());
313 >   shmFile = shm_open(shmFname, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
314 > #else
315 >   strcpy(shmFname, PMAP_SHMFNAME);
316 >   shmFile = mkstemp(shmFname);
317 > #endif      
318 >
319 >   if (shmFile < 0)
320 >      error(SYSTEM, "failed opening shared memory file in distribPhotons");
321 >
322 >   if (ftruncate(shmFile, sizeof(*photonCnt)) < 0)
323 >      error(SYSTEM, "failed setting shared memory size in distribPhotons");
324 >
325 >   photonCnt = mmap(NULL, sizeof(*photonCnt), PROT_READ | PROT_WRITE,
326 >                    MAP_SHARED, shmFile, 0);
327 >                    
328 >   if (photonCnt == MAP_FAILED)
329 >      error(SYSTEM, "failed mapping shared memory in distribPhotons");
330 >
331     if (photonRepTime)
332        eputs("\n");
333    
334     /* ===================================================================
335      * FLUX INTEGRATION - Get total photon flux from light sources
336      * =================================================================== */
337 <   for (srcIdx = 0; srcIdx < nsources; srcIdx++) {        
337 >   for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
338        unsigned portCnt = 0;
339        emap.src = source + srcIdx;
340        
341 <      do {
341 >      do {  /* Need at least one iteration if no ports! */
342           emap.port = emap.src -> sflags & SDISTANT ? photonPorts + portCnt
343                                                     : NULL;
344           photonPartition [emap.src -> so -> otype] (&emap);
# Line 398 | Line 372 | void distribPhotons (PhotonMap **pmaps)
372     if (totalFlux < FTINY)
373        error(USER, "zero flux from light sources");
374  
375 <   /* Record start time and enable progress report signal handler */
376 <   repStartTime = time(NULL);
377 <   signal(SIGCONT, pmapDistribReport);
378 <   repProgress = prePassCnt = 0;
379 <  
380 <   if (photonRepTime)
381 <      eputs("\n");
382 <  
383 <   /* ===================================================================
410 <    * 2-PASS PHOTON DISTRIBUTION
411 <    * Pass 1 (pre):  emit fraction of target photon count
412 <    * Pass 2 (main): based on outcome of pass 1, estimate remaining number
413 <    *                of photons to emit to approximate target count
414 <    * =================================================================== */
415 <   do {
416 <      double numEmit;
417 <      
418 <      if (!passCnt) {  
419 <         /* INIT PASS 1 */
420 <         /* Skip if no photons contributed after sufficient iterations; make
421 <          * it clear to user which photon maps are missing so (s)he can
422 <          * check the scene geometry and materials */
423 <         if (++prePassCnt > maxPreDistrib) {
424 <            sprintf(errmsg, "too many prepasses");
425 <
426 <            for (t = 0; t < NUM_PMAP_TYPES; t++)
427 <               if (photonMaps [t] && !photonMaps [t] -> heapEnd) {
428 <                  sprintf(errmsg2, ", no %s photons stored", pmapName [t]);
429 <                  strcat(errmsg, errmsg2);
430 <               }
431 <            
432 <            error(USER, errmsg);
433 <            break;
434 <         }
435 <
436 <         /* Num to emit is fraction of minimum target count */
437 <         numEmit = FHUGE;
375 >   /* MAIN LOOP */  
376 >   for (proc = 0; proc < numProc; proc++) {
377 >      if (!(pid = fork())) {
378 >         /* SUBPROCESS ENTERS HERE.
379 >            All opened and memory mapped files are inherited */
380 >         unsigned       passCnt = 0, prePassCnt = 0;
381 >         unsigned long  lastNumPhotons [NUM_PMAP_TYPES];
382 >         unsigned long  localNumEmitted = 0; /* Num photons emitted by this
383 >                                                subprocess alone */
384          
385 <         for (t = 0; t < NUM_PMAP_TYPES; t++)
386 <            if (photonMaps [t])
387 <               numEmit = min(photonMaps [t] -> distribTarget, numEmit);
388 <              
389 <         numEmit *= preDistrib;
390 <      }
391 <
446 <      else {            
447 <         /* INIT PASS 2 */
448 <         /* Based on the outcome of the predistribution we can now estimate
449 <          * how many more photons we have to emit for each photon map to
450 <          * meet its respective target count. This value is clamped to 0 in
451 <          * case the target has already been exceeded in the pass 1. Note
452 <          * repProgress is the number of photons emitted thus far, while
453 <          * heapEnd is the number of photons stored in each photon map. */
454 <         double maxDistribRatio = 0;
455 <
456 <         /* Set the distribution ratio for each map; this indicates how many
457 <          * photons of each respective type are stored per emitted photon,
458 <          * and is used as probability for storing a photon by addPhoton().
459 <          * Since this biases the photon density, addPhoton() promotes the
460 <          * flux of stored photons to compensate. */
461 <         for (t = 0; t < NUM_PMAP_TYPES; t++)
462 <            if ((pm = photonMaps [t])) {
463 <               pm -> distribRatio = (double)pm -> distribTarget /
464 <                                    pm -> heapEnd - 1;
465 <
466 <               /* Check if photon map "overflowed", i.e. exceeded its target
467 <                * count in the prepass; correcting the photon flux via the
468 <                * distribution ratio is no longer possible, as no more
469 <                * photons of this type will be stored, so notify the user
470 <                * rather than deliver incorrect results.
471 <                * In future we should handle this more intelligently by
472 <                * using the photonFlux in each photon map to individually
473 <                * correct the flux after distribution. */
474 <               if (pm -> distribRatio <= FTINY) {
475 <                  sprintf(errmsg,
476 <                          "%s photon map overflow in prepass, reduce -apD",
477 <                          pmapName [t]);
478 <                  error(INTERNAL, errmsg);
479 <               }
385 >         /* Seed RNGs from PID for decorellated photon distribution */
386 >         pmapSeed(randSeed + proc, partState);
387 >         pmapSeed(randSeed + proc, emitState);
388 >         pmapSeed(randSeed + proc, cntState);
389 >         pmapSeed(randSeed + proc, mediumState);
390 >         pmapSeed(randSeed + proc, scatterState);
391 >         pmapSeed(randSeed + proc, rouletteState);
392                    
481               maxDistribRatio = max(pm -> distribRatio, maxDistribRatio);
482            }
483        
484         /* Normalise distribution ratios and calculate number of photons to
485          * emit in main pass */
393           for (t = 0; t < NUM_PMAP_TYPES; t++)
394 <            if ((pm = photonMaps [t]))
395 <               pm -> distribRatio /= maxDistribRatio;
396 <              
397 <         if ((numEmit = repProgress * maxDistribRatio) < FTINY)
398 <            /* No photons left to distribute in main pass */
399 <            break;
400 <      }
401 <      
402 <      /* Set completion count for progress report */
496 <      repComplete = numEmit + repProgress;                            
497 <      
498 <      /* PHOTON DISTRIBUTION LOOP */
499 <      for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
500 <         unsigned portCnt = 0;
501 <         emap.src = source + srcIdx;
502 <                  
394 >            lastNumPhotons [t] = 0;
395 >            
396 >         /* =============================================================
397 >          * 2-PASS PHOTON DISTRIBUTION
398 >          * Pass 1 (pre):  emit fraction of target photon count
399 >          * Pass 2 (main): based on outcome of pass 1, estimate remaining
400 >          *                number of photons to emit to approximate target
401 >          *                count
402 >          * ============================================================= */
403           do {
404 <            emap.port = emap.src -> sflags & SDISTANT ? photonPorts + portCnt
505 <                                                      : NULL;
506 <            photonPartition [emap.src -> so -> otype] (&emap);
404 >            double numEmit;
405              
406 <            if (photonRepTime) {
407 <               if (!passCnt)
408 <                  sprintf(errmsg, "PREPASS %d on source %s ",
409 <                          prePassCnt, source [srcIdx].so -> oname);
410 <               else
411 <                  sprintf(errmsg, "MAIN PASS on source %s ",
412 <                          source [srcIdx].so -> oname);
413 <                      
414 <               if (emap.port) {
415 <                  sprintf(errmsg2, "via port %s ",
416 <                          photonPorts [portCnt].so -> oname);
417 <                  strcat(errmsg, errmsg2);
406 >            if (!passCnt) {  
407 >               /* INIT PASS 1 */              
408 >               /* Skip if no photons contributed after sufficient
409 >                * iterations; make it clear to user which photon maps are
410 >                * missing so (s)he can check geometry and materials */
411 >               if (++prePassCnt > maxPreDistrib) {
412 >                  sprintf(errmsg,
413 >                          "proc %d, source %s: too many prepasses",
414 >                          proc, source [srcIdx].so -> oname);              
415 >
416 >                  for (t = 0; t < NUM_PMAP_TYPES; t++)
417 >                     if (pmaps [t] && !pmaps [t] -> numPhotons) {
418 >                        sprintf(errmsg2, ", no %s photons stored",
419 >                                pmapName [t]);
420 >                        strcat(errmsg, errmsg2);
421 >                     }
422 >                  
423 >                  error(USER, errmsg);
424 >                  break;
425                 }
426 +
427 +               /* Num to emit is fraction of minimum target count */
428 +               numEmit = FHUGE;
429                
430 <               sprintf(errmsg2, "(%lu partitions)...\n", emap.numPartitions);
431 <               strcat(errmsg, errmsg2);
432 <               eputs(errmsg);
433 <               fflush(stderr);
430 >               for (t = 0; t < NUM_PMAP_TYPES; t++)
431 >                  if (pmaps [t])
432 >                     numEmit = min(pmaps [t] -> distribTarget, numEmit);
433 >                    
434 >               numEmit *= preDistrib;
435              }
436 <            
437 <            for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions;
438 <                 emap.partitionCnt++) {            
439 <               double partNumEmit;
440 <               unsigned long partEmitCnt;
436 >            else {            
437 >               /* INIT PASS 2 */
438 >               /* Based on the outcome of the predistribution we can now
439 >                * estimate how many more photons we have to emit for each
440 >                * photon map to meet its respective target count.  This
441 >                * value is clamped to 0 in case the target has already been
442 >                * exceeded in the pass 1. */
443 >               double maxDistribRatio = 0;
444 >
445 >               /* Set the distribution ratio for each map; this indicates
446 >                * how many photons of each respective type are stored per
447 >                * emitted photon, and is used as probability for storing a
448 >                * photon by newPhoton().  Since this biases the photon
449 >                * density, newPhoton() promotes the flux of stored photons
450 >                * to compensate.  */
451 >               for (t = 0; t < NUM_PMAP_TYPES; t++)
452 >                  if ((pm = pmaps [t])) {
453 >                     pm -> distribRatio = (double)pm -> distribTarget /
454 >                                          pm -> numPhotons - 1;
455 >
456 >                     /* Check if photon map "overflowed", i.e. exceeded its
457 >                      * target count in the prepass; correcting the photon
458 >                      * flux via the distribution ratio is no longer
459 >                      * possible, as no more photons of this type will be
460 >                      * stored, so notify the user rather than deliver
461 >                      * incorrect results.  In future we should handle this
462 >                      * more intelligently by using the photonFlux in each
463 >                      * photon map to individually correct the flux after
464 >                      * distribution.  */
465 >                     if (pm -> distribRatio <= FTINY) {
466 >                        sprintf(errmsg, "%s photon map overflow in "
467 >                                "prepass, reduce -apD", pmapName [t]);
468 >                        error(INTERNAL, errmsg);
469 >                     }
470 >                        
471 >                     maxDistribRatio = max(pm -> distribRatio,
472 >                                           maxDistribRatio);
473 >                  }
474                
475 <               /* Get photon origin within current source partishunn and
476 <                * build emission map */
477 <               photonOrigin [emap.src -> so -> otype] (&emap);
478 <               initPhotonEmission(&emap, pdfSamples);
479 <              
480 <               /* Number of photons to emit from ziss partishunn --
481 <                * proportional to flux; photon ray weight and scalar flux
482 <                * are uniform (the latter only varying in RGB). */
483 <               partNumEmit = numEmit * colorAvg(emap.partFlux) / totalFlux;
484 <               partEmitCnt = (unsigned long)partNumEmit;
543 <              
544 <               /* Probabilistically account for fractional photons */
545 <               if (pmapRandom(cntState) < partNumEmit - partEmitCnt)
546 <                  partEmitCnt++;
475 >               /* Normalise distribution ratios and calculate number of
476 >                * photons to emit in main pass */
477 >               for (t = 0; t < NUM_PMAP_TYPES; t++)
478 >                  if ((pm = pmaps [t]))
479 >                     pm -> distribRatio /= maxDistribRatio;
480 >                    
481 >               if ((numEmit = localNumEmitted * maxDistribRatio) < FTINY)
482 >                  /* No photons left to distribute in main pass */
483 >                  break;
484 >            }
485  
486 <               /* Integer counter avoids FP rounding errors */
487 <               while (partEmitCnt--) {
488 <                  RAY photonRay;
486 >            /* Update shared completion counter for prog.report by parent */
487 >            photonCnt -> numComplete += numEmit;                            
488 >
489 >            /* PHOTON DISTRIBUTION LOOP */
490 >            for (srcIdx = 0; srcIdx < nsources; srcIdx++) {
491 >               unsigned portCnt = 0;
492 >               emap.src = source + srcIdx;
493 >
494 >               do {  /* Need at least one iteration if no ports! */
495 >                  emap.port = emap.src -> sflags & SDISTANT
496 >                              ? photonPorts + portCnt : NULL;
497 >                  photonPartition [emap.src -> so -> otype] (&emap);
498 >
499 >                  if (photonRepTime && !proc) {
500 >                     if (!passCnt)
501 >                        sprintf(errmsg, "PREPASS %d on source %s ",
502 >                                prePassCnt, source [srcIdx].so -> oname);
503 >                     else
504 >                        sprintf(errmsg, "MAIN PASS on source %s ",
505 >                                source [srcIdx].so -> oname);
506 >                            
507 >                     if (emap.port) {
508 >                        sprintf(errmsg2, "via port %s ",
509 >                                photonPorts [portCnt].so -> oname);
510 >                        strcat(errmsg, errmsg2);
511 >                     }
512 >                    
513 >                     sprintf(errmsg2, "(%lu partitions)\n",
514 >                             emap.numPartitions);
515 >                     strcat(errmsg, errmsg2);
516 >                     eputs(errmsg);
517 >                     fflush(stderr);
518 >                  }
519                    
520 <                  /* Emit photon based on PDF and trace through scene until
521 <                   * absorbed/leaked */
522 <                  emitPhoton(&emap, &photonRay);
523 <                  tracePhoton(&photonRay);
520 >                  for (emap.partitionCnt = 0; emap.partitionCnt < emap.numPartitions;
521 >                       emap.partitionCnt++) {
522 >                     double partNumEmit;
523 >                     unsigned long partEmitCnt;
524 >                    
525 >                     /* Get photon origin within current source partishunn
526 >                      * and build emission map */
527 >                     photonOrigin [emap.src -> so -> otype] (&emap);
528 >                     initPhotonEmission(&emap, pdfSamples);
529 >                    
530 >                     /* Number of photons to emit from ziss partishunn --
531 >                      * proportional to flux; photon ray weight and scalar
532 >                      * flux are uniform (the latter only varying in RGB).
533 >                      * */
534 >                     partNumEmit = numEmit * colorAvg(emap.partFlux) /
535 >                                   totalFlux;
536 >                     partEmitCnt = (unsigned long)partNumEmit;
537 >                    
538 >                     /* Probabilistically account for fractional photons */
539 >                     if (pmapRandom(cntState) < partNumEmit - partEmitCnt)
540 >                        partEmitCnt++;
541 >
542 >                     /* Update local and shared (global) emission counter */
543 >                     photonCnt -> numEmitted += partEmitCnt;
544 >                     localNumEmitted += partEmitCnt;
545 >
546 >                     /* Integer counter avoids FP rounding errors during
547 >                      * iteration */
548 >                     while (partEmitCnt--) {
549 >                        RAY photonRay;
550 >                        
551 >                        /* Emit photon based on PDF and trace through scene
552 >                         * until absorbed/leaked */
553 >                        emitPhoton(&emap, &photonRay);
554 >                        tracePhoton(&photonRay);
555 >                     }                                          
556 >                    
557 >                     /* Update shared global photon count for each pmap */
558 >                     for (t = 0; t < NUM_PMAP_TYPES; t++)
559 >                        if (pmaps [t]) {
560 >                           photonCnt -> numPhotons [t] +=
561 >                              pmaps [t] -> numPhotons - lastNumPhotons [t];
562 >                           lastNumPhotons [t] = pmaps [t] -> numPhotons;
563 >                        }
564 >                  }
565                    
566 <                  /* Record progress */
567 <                  repProgress++;
568 <                  
569 <                  if (photonRepTime > 0 &&
570 <                      time(NULL) >= repLastTime + photonRepTime)
571 <                     pmapDistribReport();
572 <                  #ifndef BSD
573 <                     else signal(SIGCONT, pmapDistribReport);
574 <                  #endif
566 >                  portCnt++;
567 >               } while (portCnt < numPhotonPorts);
568 >            }
569 >            
570 >            for (t = 0; t < NUM_PMAP_TYPES; t++)
571 >               if (pmaps [t] && !pmaps [t] -> numPhotons) {
572 >                  /* Double preDistrib in case a photon map is empty and
573 >                   * redo pass 1 --> possibility of infinite loop for
574 >                   * pathological scenes (e.g.  absorbing materials) */
575 >                  preDistrib *= 2;
576 >                  break;
577                 }
578 +            
579 +            if (t >= NUM_PMAP_TYPES) {
580 +               /* No empty photon maps found; now do pass 2 */
581 +               passCnt++;
582 + #if 0
583 +               if (photonRepTime)
584 +                  eputs("\n");
585 + #endif
586              }
587 <                        
588 <            portCnt++;
589 <         } while (portCnt < numPhotonPorts);
587 >         } while (passCnt < 2);
588 >        
589 >         /* Unmap shared photon counters */
590 > #if 0        
591 >         munmap(photonCnt, sizeof(*photonCnt));
592 >         close(shmFile);
593 > #endif
594 >        
595 >         /* Flush heap buffa for every pmap one final time; this is required
596 >          * to prevent data corruption! */
597 >         for (t = 0; t < NUM_PMAP_TYPES; t++)
598 >            if (pmaps [t]) {
599 > #if 0            
600 >               eputs("Final flush\n");
601 > #endif              
602 >               flushPhotonHeap(pmaps [t]);
603 >               fclose(pmaps [t] -> heap);
604 > #ifdef DEBUG_PMAP              
605 >               sprintf(errmsg, "Proc %d: total %ld photons\n", getpid(),
606 >                       pmaps [t] -> numPhotons);
607 >               eputs(errmsg);
608 > #endif              
609 >            }
610 >
611 >         exit(0);
612        }
613 +      else if (pid < 0)
614 +         error(SYSTEM, "failed to fork subprocess in distribPhotons");        
615 +   }
616 +
617 +   /* PARENT PROCESS CONTINUES HERE */
618 +   /* Record start time and enable progress report signal handler */
619 +   repStartTime = time(NULL);
620 + #ifdef SIGCONT
621 +   signal(SIGCONT, pmapDistribReport);
622 + #endif
623 +  
624 +   if (photonRepTime)
625 +      eputs("\n");
626 +  
627 +   /* Wait for subprocesses to complete while reporting progress */
628 +   proc = numProc;
629 +   while (proc) {
630 +      while (waitpid(-1, &stat, WNOHANG) > 0) {
631 +         /* Subprocess exited; check status */
632 +         if (!WIFEXITED(stat) || WEXITSTATUS(stat))
633 +            error(USER, "failed photon distribution");
634        
635 +         --proc;
636 +      }
637 +      
638 +      /* Nod off for a bit and update progress  */
639 +      sleep(1);
640 +      /* Update progress report from shared subprocess counters */
641 +      repEmitted = repProgress = photonCnt -> numEmitted;
642 +      repComplete = photonCnt -> numComplete;
643 +
644        for (t = 0; t < NUM_PMAP_TYPES; t++)
645 <         if (photonMaps [t] && !photonMaps [t] -> heapEnd) {
646 <            /* Double preDistrib in case a photon map is empty and redo
647 <             * pass 1 --> possibility of infinite loop for pathological
648 <             * scenes (e.g. absorbing materials) */
649 <            preDistrib *= 2;
650 <            break;
645 >         if ((pm = pmaps [t])) {
646 > #if 0        
647 >            /* Get photon count from heapfile size for progress update */
648 >            fseek(pm -> heap, 0, SEEK_END);
649 >            pm -> numPhotons = ftell(pm -> heap) / sizeof(Photon); */
650 > #else            
651 >            /* Get global photon count from shmem updated by subprocs */
652 >            pm -> numPhotons = photonCnt -> numPhotons [t];
653 > #endif            
654           }
581      
582      if (t >= NUM_PMAP_TYPES) {
583         /* No empty photon maps found; now do pass 2 */
584         passCnt++;
585         if (photonRepTime)
586            eputs("\n");
587      }
588   } while (passCnt < 2);
655  
656 +      if (photonRepTime > 0 && time(NULL) >= repLastTime + photonRepTime)
657 +         pmapDistribReport();
658 + #ifdef SIGCONT
659 +      else signal(SIGCONT, pmapDistribReport);
660 + #endif
661 +   }
662 +
663     /* ===================================================================
664 <    * POST-DISTRIBUTION - Set photon flux and build kd-tree, etc.
664 >    * POST-DISTRIBUTION - Set photon flux and build data struct for photon
665 >    * storage, etc.
666      * =================================================================== */
667 + #ifdef SIGCONT    
668     signal(SIGCONT, SIG_DFL);
669 + #endif
670     free(emap.samples);
671    
672     /* Set photon flux (repProgress is total num emitted) */
673 <   totalFlux /= repProgress;
673 >   totalFlux /= photonCnt -> numEmitted;
674    
675 +   /* Photon counters no longer needed, unmap shared memory */
676 +   munmap(photonCnt, sizeof(*photonCnt));
677 +   close(shmFile);
678 + #if 0  
679 +   shm_unlink(shmFname);
680 + #else
681 +   unlink(shmFname);
682 + #endif      
683 +  
684     for (t = 0; t < NUM_PMAP_TYPES; t++)
685 <      if (photonMaps [t]) {
685 >      if (pmaps [t]) {
686           if (photonRepTime) {
687              sprintf(errmsg, "\nBuilding %s photon map...\n", pmapName [t]);
688              eputs(errmsg);
689              fflush(stderr);
690           }
691 <      
692 <         balancePhotons(photonMaps [t], &totalFlux);
691 >        
692 >         /* Build underlying data structure; heap is destroyed */
693 >         buildPhotonMap(pmaps [t], &totalFlux, NULL, numProc);
694        }
695 <      
695 >
696     /* Precompute photon irradiance if necessary */
697     if (preCompPmap)
698        preComputeGlobal(preCompPmap);
613 }
614
615
616
617 void photonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad)
618 /* Photon density estimate. Returns irradiance at ray -> rop. */
619 {
620   unsigned i;
621   PhotonSQNode *sq;
622   float r;
623   COLOR flux;
624
625   setcolor(irrad, 0, 0, 0);
626
627   if (!pmap -> maxGather)
628      return;
629      
630   /* Ignore sources */
631   if (ray -> ro)
632      if (islight(objptr(ray -> ro -> omod) -> otype))
633         return;
634        
635   pmap -> squeueEnd = 0;
636   findPhotons(pmap, ray);
637  
638   /* Need at least 2 photons */
639   if (pmap -> squeueEnd < 2) {
640      #ifdef PMAP_NONEFOUND  
641         sprintf(errmsg, "no photons found on %s at (%.3f, %.3f, %.3f)",
642                 ray -> ro ? ray -> ro -> oname : "<null>",
643                 ray -> rop [0], ray -> rop [1], ray -> rop [2]);
644         error(WARNING, errmsg);
645      #endif      
646
647      return;
648   }
649      
650   if (pmap -> minGather == pmap -> maxGather) {
651      /* No bias compensation. Just do a plain vanilla estimate */
652      sq = pmap -> squeue + 1;
653      
654      /* Average radius between furthest two photons to improve accuracy */      
655      r = max(sq -> dist, (sq + 1) -> dist);
656      r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r));  
657      
658      /* Skip the extra photon */
659      for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) {
660         getPhotonFlux(sq -> photon, flux);        
661 #ifdef PMAP_EPANECHNIKOV
662         /* Apply Epanechnikov kernel to photon flux (dists are squared) */
663         scalecolor(flux, 2 * (1 - sq -> dist / r));
664 #endif        
665         addcolor(irrad, flux);
666      }
667      
668      /* Divide by search area PI * r^2, 1 / PI required as ambient
669         normalisation factor */        
670      scalecolor(irrad, 1 / (PI * PI * r));
671      
672      return;
673   }
674   else
675      /* Apply bias compensation to density estimate */
676      biasComp(pmap, irrad);
677 }
678
679
680
681 void photonPreCompDensity (PhotonMap *pmap, RAY *r, COLOR irrad)
682 /* Returns precomputed photon density estimate at ray -> rop. */
683 {
684   Photon *p;
685  
686   setcolor(irrad, 0, 0, 0);
687
688   /* Ignore sources */
689   if (r -> ro && islight(objptr(r -> ro -> omod) -> otype))
690      return;
691      
692   if ((p = find1Photon(preCompPmap, r)))
693      getPhotonFlux(p, irrad);
694 }
695
696
697
698 void volumePhotonDensity (PhotonMap *pmap, RAY *ray, COLOR irrad)
699 /* Photon volume density estimate. Returns irradiance at ray -> rop. */
700 {
701   unsigned i;
702   PhotonSQNode *sq;
703   float gecc2, r, ph;
704   COLOR flux;
705
706   setcolor(irrad, 0, 0, 0);
707  
708   if (!pmap -> maxGather)
709      return;
710      
711   pmap -> squeueEnd = 0;
712   findPhotons(pmap, ray);
713  
714   /* Need at least 2 photons */
715   if (pmap -> squeueEnd < 2)
716      return;
717      
718   if (pmap -> minGather == pmap -> maxGather) {
719      /* No bias compensation. Just do a plain vanilla estimate */
720      gecc2 = ray -> gecc * ray -> gecc;
721      sq = pmap -> squeue + 1;
722      
723      /* Average radius between furthest two photons to improve accuracy */      
724      r = max(sq -> dist, (sq + 1) -> dist);
725      r = 0.25 * (pmap -> maxDist + r + 2 * sqrt(pmap -> maxDist * r));  
726      
727      /* Skip the extra photon */
728      for (i = 1 ; i < pmap -> squeueEnd; i++, sq++) {
729         /* Compute phase function for inscattering from photon */
730         if (gecc2 <= FTINY)
731            ph = 1;
732         else {
733            ph = DOT(ray -> rdir, sq -> photon -> norm) / 127;
734            ph = 1 + gecc2 - 2 * ray -> gecc * ph;
735            ph = (1 - gecc2) / (ph * sqrt(ph));
736         }
737        
738         getPhotonFlux(sq -> photon, flux);
739         scalecolor(flux, ph);
740         addcolor(irrad, flux);
741      }
742      
743      /* Divide by search volume 4 / 3 * PI * r^3 and phase function
744         normalization factor 1 / (4 * PI) */
745      scalecolor(irrad, 3 / (16 * PI * PI * r * sqrt(r)));
746      
747      return;
748   }
749  
750   else
751      /* Apply bias compensation to density estimate */
752      volumeBiasComp(pmap, ray, irrad);
699   }

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