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root/radiance/ray/src/cv/bsdfmesh.c
Revision: 2.16
Committed: Wed Feb 19 05:16:06 2014 UTC (10 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.15: +8 -44 lines
Log Message:
Eliminated redundant code added in last change to bsdfmesh.c

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdfmesh.c,v 2.15 2014/02/18 16:06:51 greg Exp $";
3 #endif
4 /*
5 * Create BSDF advection mesh from radial basis functions.
6 *
7 * G. Ward
8 */
9
10 #ifndef _WIN32
11 #include <unistd.h>
12 #include <sys/wait.h>
13 #include <sys/mman.h>
14 #endif
15 #define _USE_MATH_DEFINES
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <string.h>
19 #include <math.h>
20 #include "bsdfrep.h"
21 /* number of processes to run */
22 int nprocs = 1;
23 /* number of children (-1 in child) */
24 static int nchild = 0;
25
26 typedef struct {
27 int nrows, ncols; /* array size (matches migration) */
28 float *price; /* migration prices */
29 short *sord; /* sort for each row, low to high */
30 float *prow; /* current price row */
31 } PRICEMAT; /* sorted pricing matrix */
32
33 #define pricerow(p,i) ((p)->price + (i)*(p)->ncols)
34 #define psortrow(p,i) ((p)->sord + (i)*(p)->ncols)
35
36 /* Create a new migration holder (sharing memory for multiprocessing) */
37 static MIGRATION *
38 new_migration(RBFNODE *from_rbf, RBFNODE *to_rbf)
39 {
40 size_t memlen = sizeof(MIGRATION) +
41 sizeof(float)*(from_rbf->nrbf*to_rbf->nrbf - 1);
42 MIGRATION *newmig;
43 #ifdef _WIN32
44 if (nprocs > 1)
45 fprintf(stderr, "%s: warning - multiprocessing not supported\n",
46 progname);
47 nprocs = 1;
48 newmig = (MIGRATION *)malloc(memlen);
49 #else
50 if (nprocs <= 1) { /* single process? */
51 newmig = (MIGRATION *)malloc(memlen);
52 } else { /* else need to share memory */
53 newmig = (MIGRATION *)mmap(NULL, memlen, PROT_READ|PROT_WRITE,
54 MAP_ANON|MAP_SHARED, -1, 0);
55 if ((void *)newmig == MAP_FAILED)
56 newmig = NULL;
57 }
58 #endif
59 if (newmig == NULL) {
60 fprintf(stderr, "%s: cannot allocate new migration\n", progname);
61 exit(1);
62 }
63 newmig->rbfv[0] = from_rbf;
64 newmig->rbfv[1] = to_rbf;
65 /* insert in edge lists */
66 newmig->enxt[0] = from_rbf->ejl;
67 from_rbf->ejl = newmig;
68 newmig->enxt[1] = to_rbf->ejl;
69 to_rbf->ejl = newmig;
70 newmig->next = mig_list; /* push onto global list */
71 return(mig_list = newmig);
72 }
73
74 #ifdef _WIN32
75 #define await_children(n) (void)(n)
76 #define run_subprocess() 0
77 #define end_subprocess() (void)0
78 #else
79
80 /* Wait for the specified number of child processes to complete */
81 static void
82 await_children(int n)
83 {
84 int exit_status = 0;
85
86 if (n > nchild)
87 n = nchild;
88 while (n-- > 0) {
89 int status;
90 if (wait(&status) < 0) {
91 fprintf(stderr, "%s: missing child(ren)!\n", progname);
92 nchild = 0;
93 break;
94 }
95 --nchild;
96 if (status) { /* something wrong */
97 if ((status = WEXITSTATUS(status)))
98 exit_status = status;
99 else
100 exit_status += !exit_status;
101 fprintf(stderr, "%s: subprocess died\n", progname);
102 n = nchild; /* wait for the rest */
103 }
104 }
105 if (exit_status)
106 exit(exit_status);
107 }
108
109 /* Start child process if multiprocessing selected */
110 static pid_t
111 run_subprocess(void)
112 {
113 int status;
114 pid_t pid;
115
116 if (nprocs <= 1) /* any children requested? */
117 return(0);
118 await_children(nchild + 1 - nprocs); /* free up child process */
119 if ((pid = fork())) {
120 if (pid < 0) {
121 fprintf(stderr, "%s: cannot fork subprocess\n",
122 progname);
123 await_children(nchild);
124 exit(1);
125 }
126 ++nchild; /* subprocess started */
127 return(pid);
128 }
129 nchild = -1;
130 return(0); /* put child to work */
131 }
132
133 /* If we are in subprocess, call exit */
134 #define end_subprocess() if (nchild < 0) _exit(0); else
135
136 #endif /* ! _WIN32 */
137
138 /* Comparison routine needed for sorting price row */
139 static int
140 msrt_cmp(void *b, const void *p1, const void *p2)
141 {
142 PRICEMAT *pm = (PRICEMAT *)b;
143 float c1 = pm->prow[*(const short *)p1];
144 float c2 = pm->prow[*(const short *)p2];
145
146 if (c1 > c2) return(1);
147 if (c1 < c2) return(-1);
148 return(0);
149 }
150
151 /* Compute (and allocate) migration price matrix for optimization */
152 static void
153 price_routes(PRICEMAT *pm, const RBFNODE *from_rbf, const RBFNODE *to_rbf)
154 {
155 FVECT *vto = (FVECT *)malloc(sizeof(FVECT) * to_rbf->nrbf);
156 int i, j;
157
158 pm->nrows = from_rbf->nrbf;
159 pm->ncols = to_rbf->nrbf;
160 pm->price = (float *)malloc(sizeof(float) * pm->nrows*pm->ncols);
161 pm->sord = (short *)malloc(sizeof(short) * pm->nrows*pm->ncols);
162
163 if ((pm->price == NULL) | (pm->sord == NULL) | (vto == NULL)) {
164 fprintf(stderr, "%s: Out of memory in migration_costs()\n",
165 progname);
166 exit(1);
167 }
168 for (j = to_rbf->nrbf; j--; ) /* save repetitive ops. */
169 ovec_from_pos(vto[j], to_rbf->rbfa[j].gx, to_rbf->rbfa[j].gy);
170
171 for (i = from_rbf->nrbf; i--; ) {
172 const double from_ang = R2ANG(from_rbf->rbfa[i].crad);
173 FVECT vfrom;
174 short *srow;
175 ovec_from_pos(vfrom, from_rbf->rbfa[i].gx, from_rbf->rbfa[i].gy);
176 pm->prow = pricerow(pm,i);
177 srow = psortrow(pm,i);
178 for (j = to_rbf->nrbf; j--; ) {
179 double d; /* quadratic cost function */
180 d = DOT(vfrom, vto[j]);
181 d = (d >= 1.) ? .0 : acos(d);
182 pm->prow[j] = d*d;
183 d = R2ANG(to_rbf->rbfa[j].crad) - from_ang;
184 pm->prow[j] += d*d;
185 srow[j] = j;
186 }
187 qsort_r(srow, pm->ncols, sizeof(short), pm, &msrt_cmp);
188 }
189 free(vto);
190 }
191
192 /* Free price matrix */
193 static void
194 free_routes(PRICEMAT *pm)
195 {
196 free(pm->price); pm->price = NULL;
197 free(pm->sord); pm->sord = NULL;
198 }
199
200 /* Compute minimum (optimistic) cost for moving the given source material */
201 static double
202 min_cost(double amt2move, const double *avail, const PRICEMAT *pm, int s)
203 {
204 const short *srow = psortrow(pm,s);
205 const float *prow = pricerow(pm,s);
206 double total_cost = 0;
207 int j;
208 /* move cheapest first */
209 for (j = 0; (j < pm->ncols) & (amt2move > FTINY); j++) {
210 int d = srow[j];
211 double amt = (amt2move < avail[d]) ? amt2move : avail[d];
212
213 total_cost += amt * prow[d];
214 amt2move -= amt;
215 }
216 return(total_cost);
217 }
218
219 /* Compare entries by moving price */
220 static int
221 rmovcmp(void *b, const void *p1, const void *p2)
222 {
223 PRICEMAT *pm = (PRICEMAT *)b;
224 const short *ij1 = (const short *)p1;
225 const short *ij2 = (const short *)p2;
226 float price_diff;
227
228 if (ij1[1] < 0) return(ij2[1] >= 0);
229 if (ij2[1] < 0) return(-1);
230 price_diff = pricerow(pm,ij1[0])[ij1[1]] - pricerow(pm,ij2[0])[ij2[1]];
231 if (price_diff > 0) return(1);
232 if (price_diff < 0) return(-1);
233 return(0);
234 }
235
236 /* Take a step in migration by choosing reasonable bucket to transfer */
237 static double
238 migration_step(MIGRATION *mig, double *src_rem, double *dst_rem, PRICEMAT *pm)
239 {
240 const int max2check = 100;
241 const double maxamt = 1./(double)pm->ncols;
242 const double minamt = maxamt*1e-4;
243 double *src_cost;
244 short (*rord)[2];
245 struct {
246 int s, d; /* source and destination */
247 double price; /* price estimate per amount moved */
248 double amt; /* amount we can move */
249 } cur, best;
250 int r2check, i, ri;
251 /*
252 * Check cheapest available routes only -- a higher adjusted
253 * destination price implies that another source is closer, so
254 * we can hold off considering more expensive options until
255 * some other (hopefully better) moves have been made.
256 */
257 /* most promising row order */
258 rord = (short (*)[2])malloc(sizeof(short)*2*pm->nrows);
259 if (rord == NULL)
260 goto memerr;
261 for (ri = pm->nrows; ri--; ) {
262 rord[ri][0] = ri;
263 rord[ri][1] = -1;
264 if (src_rem[ri] <= minamt) /* enough source material? */
265 continue;
266 for (i = 0; i < pm->ncols; i++)
267 if (dst_rem[ rord[ri][1] = psortrow(pm,ri)[i] ] > minamt)
268 break;
269 if (i >= pm->ncols) { /* moved all we can? */
270 free(rord);
271 return(.0);
272 }
273 }
274 if (pm->nrows > max2check) /* sort if too many sources */
275 qsort_r(rord, pm->nrows, sizeof(short)*2, pm, &rmovcmp);
276 /* allocate cost array */
277 src_cost = (double *)malloc(sizeof(double)*pm->nrows);
278 if (src_cost == NULL)
279 goto memerr;
280 for (i = pm->nrows; i--; ) /* starting costs for diff. */
281 src_cost[i] = min_cost(src_rem[i], dst_rem, pm, i);
282 /* find best source & dest. */
283 best.s = best.d = -1; best.price = FHUGE; best.amt = 0;
284 if ((r2check = pm->nrows) > max2check)
285 r2check = max2check; /* put a limit on search */
286 for (ri = 0; ri < r2check; ri++) { /* check each source row */
287 double cost_others = 0;
288 cur.s = rord[ri][0];
289 if ((cur.d = rord[ri][1]) < 0 ||
290 (cur.price = pricerow(pm,cur.s)[cur.d]) >= best.price) {
291 if (pm->nrows > max2check) break; /* sorted end */
292 continue; /* else skip this one */
293 }
294 cur.amt = (src_rem[cur.s] < dst_rem[cur.d]) ?
295 src_rem[cur.s] : dst_rem[cur.d];
296 /* don't just leave smidgen */
297 if (cur.amt > maxamt*1.02) cur.amt = maxamt;
298 dst_rem[cur.d] -= cur.amt; /* add up opportunity costs */
299 for (i = pm->nrows; i--; )
300 if (i != cur.s)
301 cost_others += min_cost(src_rem[i], dst_rem, pm, i)
302 - src_cost[i];
303 dst_rem[cur.d] += cur.amt; /* undo trial move */
304 cur.price += cost_others/cur.amt; /* adjust effective price */
305 if (cur.price < best.price) /* are we better than best? */
306 best = cur;
307 }
308 free(src_cost); /* clean up */
309 free(rord);
310 if ((best.s < 0) | (best.d < 0)) /* nothing left to move? */
311 return(.0);
312 /* else make the actual move */
313 mtx_coef(mig,best.s,best.d) += best.amt;
314 src_rem[best.s] -= best.amt;
315 dst_rem[best.d] -= best.amt;
316 return(best.amt);
317 memerr:
318 fprintf(stderr, "%s: Out of memory in migration_step()\n", progname);
319 exit(1);
320 }
321
322 /* Compute and insert migration along directed edge (may fork child) */
323 static MIGRATION *
324 create_migration(RBFNODE *from_rbf, RBFNODE *to_rbf)
325 {
326 const double end_thresh = 5e-6;
327 PRICEMAT pmtx;
328 MIGRATION *newmig;
329 double *src_rem, *dst_rem;
330 double total_rem = 1., move_amt;
331 int i, j;
332 /* check if exists already */
333 for (newmig = from_rbf->ejl; newmig != NULL;
334 newmig = nextedge(from_rbf,newmig))
335 if (newmig->rbfv[1] == to_rbf)
336 return(NULL);
337 /* else allocate */
338 #ifdef DEBUG
339 fprintf(stderr, "Building path from (theta,phi) (%.1f,%.1f) ",
340 get_theta180(from_rbf->invec),
341 get_phi360(from_rbf->invec));
342 fprintf(stderr, "to (%.1f,%.1f) with %d x %d matrix\n",
343 get_theta180(to_rbf->invec),
344 get_phi360(to_rbf->invec),
345 from_rbf->nrbf, to_rbf->nrbf);
346 #endif
347 newmig = new_migration(from_rbf, to_rbf);
348 if (run_subprocess())
349 return(newmig); /* child continues */
350 price_routes(&pmtx, from_rbf, to_rbf);
351 src_rem = (double *)malloc(sizeof(double)*from_rbf->nrbf);
352 dst_rem = (double *)malloc(sizeof(double)*to_rbf->nrbf);
353 if ((src_rem == NULL) | (dst_rem == NULL)) {
354 fprintf(stderr, "%s: Out of memory in create_migration()\n",
355 progname);
356 exit(1);
357 }
358 /* starting quantities */
359 memset(newmig->mtx, 0, sizeof(float)*from_rbf->nrbf*to_rbf->nrbf);
360 for (i = from_rbf->nrbf; i--; )
361 src_rem[i] = rbf_volume(&from_rbf->rbfa[i]) / from_rbf->vtotal;
362 for (j = to_rbf->nrbf; j--; )
363 dst_rem[j] = rbf_volume(&to_rbf->rbfa[j]) / to_rbf->vtotal;
364
365 do { /* move a bit at a time */
366 move_amt = migration_step(newmig, src_rem, dst_rem, &pmtx);
367 total_rem -= move_amt;
368 } while ((total_rem > end_thresh) & (move_amt > 0));
369
370 for (i = from_rbf->nrbf; i--; ) { /* normalize final matrix */
371 double nf = rbf_volume(&from_rbf->rbfa[i]);
372 if (nf <= FTINY) continue;
373 nf = from_rbf->vtotal / nf;
374 for (j = to_rbf->nrbf; j--; )
375 mtx_coef(newmig,i,j) *= nf; /* row now sums to 1.0 */
376 }
377 end_subprocess(); /* exit here if subprocess */
378 free_routes(&pmtx); /* free working arrays */
379 free(src_rem);
380 free(dst_rem);
381 return(newmig);
382 }
383
384 /* Check if prospective vertex would create overlapping triangle */
385 static int
386 overlaps_tri(const RBFNODE *bv0, const RBFNODE *bv1, const RBFNODE *pv)
387 {
388 const MIGRATION *ej;
389 RBFNODE *vother[2];
390 int im_rev;
391 /* find shared edge in mesh */
392 for (ej = pv->ejl; ej != NULL; ej = nextedge(pv,ej)) {
393 const RBFNODE *tv = opp_rbf(pv,ej);
394 if (tv == bv0) {
395 im_rev = is_rev_tri(ej->rbfv[0]->invec,
396 ej->rbfv[1]->invec, bv1->invec);
397 break;
398 }
399 if (tv == bv1) {
400 im_rev = is_rev_tri(ej->rbfv[0]->invec,
401 ej->rbfv[1]->invec, bv0->invec);
402 break;
403 }
404 }
405 if (!get_triangles(vother, ej)) /* triangle on same side? */
406 return(0);
407 return(vother[im_rev] != NULL);
408 }
409
410 /* Find convex hull vertex to complete triangle (oriented call) */
411 static RBFNODE *
412 find_chull_vert(const RBFNODE *rbf0, const RBFNODE *rbf1)
413 {
414 FVECT vmid, vejn, vp;
415 RBFNODE *rbf, *rbfbest = NULL;
416 double dprod, area2, bestarea2 = FHUGE, bestdprod = -.5;
417
418 VSUB(vejn, rbf1->invec, rbf0->invec);
419 VADD(vmid, rbf0->invec, rbf1->invec);
420 if (normalize(vejn) == 0 || normalize(vmid) == 0)
421 return(NULL);
422 /* XXX exhaustive search */
423 /* Find triangle with minimum rotation from perpendicular */
424 for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
425 if ((rbf == rbf0) | (rbf == rbf1))
426 continue;
427 tri_orient(vp, rbf0->invec, rbf1->invec, rbf->invec);
428 if (DOT(vp, vmid) <= FTINY)
429 continue; /* wrong orientation */
430 area2 = .25*DOT(vp,vp);
431 VSUB(vp, rbf->invec, vmid);
432 dprod = -DOT(vp, vejn);
433 VSUM(vp, vp, vejn, dprod); /* above guarantees non-zero */
434 dprod = DOT(vp, vmid) / VLEN(vp);
435 if (dprod <= bestdprod + FTINY*(1 - 2*(area2 < bestarea2)))
436 continue; /* found better already */
437 if (overlaps_tri(rbf0, rbf1, rbf))
438 continue; /* overlaps another triangle */
439 rbfbest = rbf;
440 bestdprod = dprod; /* new one to beat */
441 bestarea2 = area2;
442 }
443 return(rbfbest);
444 }
445
446 /* Create new migration edge and grow mesh recursively around it */
447 static void
448 mesh_from_edge(MIGRATION *edge)
449 {
450 MIGRATION *ej0, *ej1;
451 RBFNODE *tvert[2];
452
453 if (edge == NULL)
454 return;
455 /* triangle on either side? */
456 get_triangles(tvert, edge);
457 if (tvert[0] == NULL) { /* grow mesh on right */
458 tvert[0] = find_chull_vert(edge->rbfv[0], edge->rbfv[1]);
459 if (tvert[0] != NULL) {
460 if (tvert[0]->ord > edge->rbfv[0]->ord)
461 ej0 = create_migration(edge->rbfv[0], tvert[0]);
462 else
463 ej0 = create_migration(tvert[0], edge->rbfv[0]);
464 if (tvert[0]->ord > edge->rbfv[1]->ord)
465 ej1 = create_migration(edge->rbfv[1], tvert[0]);
466 else
467 ej1 = create_migration(tvert[0], edge->rbfv[1]);
468 mesh_from_edge(ej0);
469 mesh_from_edge(ej1);
470 }
471 } else if (tvert[1] == NULL) { /* grow mesh on left */
472 tvert[1] = find_chull_vert(edge->rbfv[1], edge->rbfv[0]);
473 if (tvert[1] != NULL) {
474 if (tvert[1]->ord > edge->rbfv[0]->ord)
475 ej0 = create_migration(edge->rbfv[0], tvert[1]);
476 else
477 ej0 = create_migration(tvert[1], edge->rbfv[0]);
478 if (tvert[1]->ord > edge->rbfv[1]->ord)
479 ej1 = create_migration(edge->rbfv[1], tvert[1]);
480 else
481 ej1 = create_migration(tvert[1], edge->rbfv[1]);
482 mesh_from_edge(ej0);
483 mesh_from_edge(ej1);
484 }
485 }
486 }
487
488 /* Add normal direction if missing */
489 static void
490 check_normal_incidence(void)
491 {
492 static const FVECT norm_vec = {.0, .0, 1.};
493 const int saved_nprocs = nprocs;
494 RBFNODE *near_rbf, *mir_rbf, *rbf;
495 double bestd;
496 int n;
497
498 if (dsf_list == NULL)
499 return; /* XXX should be error? */
500 near_rbf = dsf_list;
501 bestd = input_orient*near_rbf->invec[2];
502 if (single_plane_incident) { /* ordered plane incidence? */
503 if (bestd >= 1.-2.*FTINY)
504 return; /* already have normal */
505 } else {
506 switch (inp_coverage) {
507 case INP_QUAD1:
508 case INP_QUAD2:
509 case INP_QUAD3:
510 case INP_QUAD4:
511 break; /* quadrilateral symmetry? */
512 default:
513 return; /* else we can interpolate */
514 }
515 for (rbf = near_rbf->next; rbf != NULL; rbf = rbf->next) {
516 const double d = input_orient*rbf->invec[2];
517 if (d >= 1.-2.*FTINY)
518 return; /* seems we have normal */
519 if (d > bestd) {
520 near_rbf = rbf;
521 bestd = d;
522 }
523 }
524 }
525 if (mig_list != NULL) { /* need to be called first */
526 fprintf(stderr, "%s: Late call to check_normal_incidence()\n",
527 progname);
528 exit(1);
529 }
530 #ifdef DEBUG
531 fprintf(stderr, "Interpolating normal incidence by mirroring (%.1f,%.1f)\n",
532 get_theta180(near_rbf->invec), get_phi360(near_rbf->invec));
533 #endif
534 /* mirror nearest incidence */
535 n = sizeof(RBFNODE) + sizeof(RBFVAL)*(near_rbf->nrbf-1);
536 mir_rbf = (RBFNODE *)malloc(n);
537 if (mir_rbf == NULL)
538 goto memerr;
539 memcpy(mir_rbf, near_rbf, n);
540 mir_rbf->ord = near_rbf->ord - 1; /* not used, I think */
541 mir_rbf->next = NULL;
542 rev_rbf_symmetry(mir_rbf, MIRROR_X|MIRROR_Y);
543 nprocs = 1; /* compute migration matrix */
544 if (mig_list != create_migration(mir_rbf, near_rbf))
545 exit(1); /* XXX should never happen! */
546 /* interpolate normal dist. */
547 rbf = e_advect_rbf(mig_list, norm_vec, 2*near_rbf->nrbf);
548 nprocs = saved_nprocs; /* final clean-up */
549 free(mir_rbf);
550 free(mig_list);
551 mig_list = near_rbf->ejl = NULL;
552 insert_dsf(rbf); /* insert interpolated normal */
553 return;
554 memerr:
555 fprintf(stderr, "%s: Out of memory in check_normal_incidence()\n",
556 progname);
557 exit(1);
558 }
559
560 /* Build our triangle mesh from recorded RBFs */
561 void
562 build_mesh(void)
563 {
564 double best2 = M_PI*M_PI;
565 RBFNODE *shrt_edj[2];
566 RBFNODE *rbf0, *rbf1;
567 /* add normal if needed */
568 check_normal_incidence();
569 /* check if isotropic */
570 if (single_plane_incident) {
571 for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next)
572 if (rbf0->next != NULL)
573 create_migration(rbf0, rbf0->next);
574 await_children(nchild);
575 return;
576 }
577 shrt_edj[0] = shrt_edj[1] = NULL; /* start w/ shortest edge */
578 for (rbf0 = dsf_list; rbf0 != NULL; rbf0 = rbf0->next)
579 for (rbf1 = rbf0->next; rbf1 != NULL; rbf1 = rbf1->next) {
580 double dist2 = 2. - 2.*DOT(rbf0->invec,rbf1->invec);
581 if (dist2 < best2) {
582 shrt_edj[0] = rbf0;
583 shrt_edj[1] = rbf1;
584 best2 = dist2;
585 }
586 }
587 if (shrt_edj[0] == NULL) {
588 fprintf(stderr, "%s: Cannot find shortest edge\n", progname);
589 exit(1);
590 }
591 /* build mesh from this edge */
592 if (shrt_edj[0]->ord < shrt_edj[1]->ord)
593 mesh_from_edge(create_migration(shrt_edj[0], shrt_edj[1]));
594 else
595 mesh_from_edge(create_migration(shrt_edj[1], shrt_edj[0]));
596 /* complete migrations */
597 await_children(nchild);
598 }