ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/common/bsdf.c
Revision: 2.21
Committed: Sun Apr 17 17:45:13 2011 UTC (13 years, 1 month ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.20: +9 -5 lines
Log Message:
Minor fixes

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdf.c,v 2.20 2011/04/11 03:47:46 greg Exp $";
3 #endif
4 /*
5 * bsdf.c
6 *
7 * Definitions for bidirectional scattering distribution functions.
8 *
9 * Created by Greg Ward on 1/10/11.
10 *
11 */
12
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <math.h>
16 #include "ezxml.h"
17 #include "hilbert.h"
18 #include "bsdf.h"
19 #include "bsdf_m.h"
20 #include "bsdf_t.h"
21
22 /* English ASCII strings corresponding to ennumerated errors */
23 const char *SDerrorEnglish[] = {
24 "No error",
25 "Memory error",
26 "File input/output error",
27 "File format error",
28 "Illegal argument",
29 "Invalid data",
30 "Unsupported feature",
31 "Internal program error",
32 "Unknown error"
33 };
34
35 /* Additional information on last error (ASCII English) */
36 char SDerrorDetail[256];
37
38 /* Cache of loaded BSDFs */
39 struct SDCache_s *SDcacheList = NULL;
40
41 /* Retain BSDFs in cache list */
42 int SDretainSet = SDretainNone;
43
44 /* Report any error to the indicated stream (in English) */
45 SDError
46 SDreportEnglish(SDError ec, FILE *fp)
47 {
48 if (!ec)
49 return SDEnone;
50 if ((ec < SDEnone) | (ec > SDEunknown)) {
51 SDerrorDetail[0] = '\0';
52 ec = SDEunknown;
53 }
54 if (fp == NULL)
55 return ec;
56 fputs(SDerrorEnglish[ec], fp);
57 if (SDerrorDetail[0]) {
58 fputs(": ", fp);
59 fputs(SDerrorDetail, fp);
60 }
61 fputc('\n', fp);
62 if (fp != stderr)
63 fflush(fp);
64 return ec;
65 }
66
67 static double
68 to_meters( /* return factor to convert given unit to meters */
69 const char *unit
70 )
71 {
72 if (unit == NULL) return(1.); /* safe assumption? */
73 if (!strcasecmp(unit, "Meter")) return(1.);
74 if (!strcasecmp(unit, "Foot")) return(.3048);
75 if (!strcasecmp(unit, "Inch")) return(.0254);
76 if (!strcasecmp(unit, "Centimeter")) return(.01);
77 if (!strcasecmp(unit, "Millimeter")) return(.001);
78 sprintf(SDerrorDetail, "Unknown dimensional unit '%s'", unit);
79 return(-1.);
80 }
81
82 /* Load geometric dimensions and description (if any) */
83 static SDError
84 SDloadGeometry(SDData *sd, ezxml_t wdb)
85 {
86 ezxml_t geom;
87 double cfact;
88 const char *fmt, *mgfstr;
89
90 if (wdb == NULL) /* no geometry section? */
91 return SDEnone;
92 sd->dim[0] = sd->dim[1] = sd->dim[2] = .0;
93 if ((geom = ezxml_child(wdb, "Width")) != NULL)
94 sd->dim[0] = atof(ezxml_txt(geom)) *
95 to_meters(ezxml_attr(geom, "unit"));
96 if ((geom = ezxml_child(wdb, "Height")) != NULL)
97 sd->dim[1] = atof(ezxml_txt(geom)) *
98 to_meters(ezxml_attr(geom, "unit"));
99 if ((geom = ezxml_child(wdb, "Thickness")) != NULL)
100 sd->dim[2] = atof(ezxml_txt(geom)) *
101 to_meters(ezxml_attr(geom, "unit"));
102 if ((sd->dim[0] < .0) | (sd->dim[1] < .0) | (sd->dim[2] < .0)) {
103 sprintf(SDerrorDetail, "Negative size in \"%s\"", sd->name);
104 return SDEdata;
105 }
106 if ((geom = ezxml_child(wdb, "Geometry")) == NULL ||
107 (mgfstr = ezxml_txt(geom)) == NULL)
108 return SDEnone;
109 if ((fmt = ezxml_attr(geom, "format")) != NULL &&
110 strcasecmp(fmt, "MGF")) {
111 sprintf(SDerrorDetail,
112 "Unrecognized geometry format '%s' in \"%s\"",
113 fmt, sd->name);
114 return SDEsupport;
115 }
116 cfact = to_meters(ezxml_attr(geom, "unit"));
117 sd->mgf = (char *)malloc(strlen(mgfstr)+32);
118 if (sd->mgf == NULL) {
119 strcpy(SDerrorDetail, "Out of memory in SDloadGeometry");
120 return SDEmemory;
121 }
122 if (cfact < 0.99 || cfact > 1.01)
123 sprintf(sd->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr);
124 else
125 strcpy(sd->mgf, mgfstr);
126 return SDEnone;
127 }
128
129 /* Load a BSDF struct from the given file (free first and keep name) */
130 SDError
131 SDloadFile(SDData *sd, const char *fname)
132 {
133 SDError lastErr;
134 ezxml_t fl, wtl;
135
136 if ((sd == NULL) | (fname == NULL || !*fname))
137 return SDEargument;
138 /* free old data, keeping name */
139 SDfreeBSDF(sd);
140 /* parse XML file */
141 fl = ezxml_parse_file(fname);
142 if (fl == NULL) {
143 sprintf(SDerrorDetail, "Cannot open BSDF \"%s\"", fname);
144 return SDEfile;
145 }
146 if (ezxml_error(fl)[0]) {
147 sprintf(SDerrorDetail, "BSDF \"%s\" %s", fname, ezxml_error(fl));
148 ezxml_free(fl);
149 return SDEformat;
150 }
151 if (strcmp(ezxml_name(fl), "WindowElement")) {
152 sprintf(SDerrorDetail,
153 "BSDF \"%s\": top level node not 'WindowElement'",
154 sd->name);
155 ezxml_free(fl);
156 return SDEformat;
157 }
158 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
159 if (wtl == NULL) {
160 sprintf(SDerrorDetail, "BSDF \"%s\": no optical layer'",
161 sd->name);
162 ezxml_free(fl);
163 return SDEformat;
164 }
165 /* load geometry if present */
166 lastErr = SDloadGeometry(sd, ezxml_child(wtl, "Material"));
167 if (lastErr)
168 return lastErr;
169 /* try loading variable resolution data */
170 lastErr = SDloadTre(sd, wtl);
171 /* check our result */
172 switch (lastErr) {
173 case SDEformat:
174 case SDEdata:
175 case SDEsupport: /* possibly we just tried the wrong format */
176 lastErr = SDloadMtx(sd, wtl);
177 break;
178 default: /* variable res. OK else serious error */
179 break;
180 }
181 /* done with XML file */
182 ezxml_free(fl);
183
184 if (lastErr) { /* was there a load error? */
185 SDfreeBSDF(sd);
186 return lastErr;
187 }
188 /* remove any insignificant components */
189 if (sd->rf != NULL && sd->rf->maxHemi <= .001) {
190 SDfreeSpectralDF(sd->rf); sd->rf = NULL;
191 }
192 if (sd->rb != NULL && sd->rb->maxHemi <= .001) {
193 SDfreeSpectralDF(sd->rb); sd->rb = NULL;
194 }
195 if (sd->tf != NULL && sd->tf->maxHemi <= .001) {
196 SDfreeSpectralDF(sd->tf); sd->tf = NULL;
197 }
198 /* return success */
199 return SDEnone;
200 }
201
202 /* Allocate new spectral distribution function */
203 SDSpectralDF *
204 SDnewSpectralDF(int nc)
205 {
206 SDSpectralDF *df;
207
208 if (nc <= 0) {
209 strcpy(SDerrorDetail, "Zero component spectral DF request");
210 return NULL;
211 }
212 df = (SDSpectralDF *)malloc(sizeof(SDSpectralDF) +
213 (nc-1)*sizeof(SDComponent));
214 if (df == NULL) {
215 sprintf(SDerrorDetail,
216 "Cannot allocate %d component spectral DF", nc);
217 return NULL;
218 }
219 df->minProjSA = .0;
220 df->maxHemi = .0;
221 df->ncomp = nc;
222 memset(df->comp, 0, nc*sizeof(SDComponent));
223 return df;
224 }
225
226 /* Free cached cumulative distributions for BSDF component */
227 void
228 SDfreeCumulativeCache(SDSpectralDF *df)
229 {
230 int n;
231 SDCDst *cdp;
232
233 if (df == NULL)
234 return;
235 for (n = df->ncomp; n-- > 0; )
236 while ((cdp = df->comp[n].cdList) != NULL) {
237 df->comp[n].cdList = cdp->next;
238 free(cdp);
239 }
240 }
241
242 /* Free a spectral distribution function */
243 void
244 SDfreeSpectralDF(SDSpectralDF *df)
245 {
246 int n;
247
248 if (df == NULL)
249 return;
250 SDfreeCumulativeCache(df);
251 for (n = df->ncomp; n-- > 0; )
252 (*df->comp[n].func->freeSC)(df->comp[n].dist);
253 free(df);
254 }
255
256 /* Shorten file path to useable BSDF name, removing suffix */
257 void
258 SDclipName(char *res, const char *fname)
259 {
260 const char *cp, *dot = NULL;
261
262 for (cp = fname; *cp; cp++)
263 if (*cp == '.')
264 dot = cp;
265 if ((dot == NULL) | (dot < fname+2))
266 dot = cp;
267 if (dot - fname >= SDnameLn)
268 fname = dot - SDnameLn + 1;
269 while (fname < dot)
270 *res++ = *fname++;
271 *res = '\0';
272 }
273
274 /* Initialize an unused BSDF struct (simply clears to zeroes) */
275 void
276 SDclearBSDF(SDData *sd, const char *fname)
277 {
278 if (sd == NULL)
279 return;
280 memset(sd, 0, sizeof(SDData));
281 if (fname == NULL)
282 return;
283 SDclipName(sd->name, fname);
284 }
285
286 /* Free data associated with BSDF struct */
287 void
288 SDfreeBSDF(SDData *sd)
289 {
290 if (sd == NULL)
291 return;
292 if (sd->mgf != NULL) {
293 free(sd->mgf);
294 sd->mgf = NULL;
295 }
296 if (sd->rf != NULL) {
297 SDfreeSpectralDF(sd->rf);
298 sd->rf = NULL;
299 }
300 if (sd->rb != NULL) {
301 SDfreeSpectralDF(sd->rb);
302 sd->rb = NULL;
303 }
304 if (sd->tf != NULL) {
305 SDfreeSpectralDF(sd->tf);
306 sd->tf = NULL;
307 }
308 sd->rLambFront.cieY = .0;
309 sd->rLambFront.spec.flags = 0;
310 sd->rLambBack.cieY = .0;
311 sd->rLambBack.spec.flags = 0;
312 sd->tLamb.cieY = .0;
313 sd->tLamb.spec.flags = 0;
314 }
315
316 /* Find writeable BSDF by name, or allocate new cache entry if absent */
317 SDData *
318 SDgetCache(const char *bname)
319 {
320 struct SDCache_s *sdl;
321 char sdnam[SDnameLn];
322
323 if (bname == NULL)
324 return NULL;
325
326 SDclipName(sdnam, bname);
327 for (sdl = SDcacheList; sdl != NULL; sdl = sdl->next)
328 if (!strcmp(sdl->bsdf.name, sdnam)) {
329 sdl->refcnt++;
330 return &sdl->bsdf;
331 }
332
333 sdl = (struct SDCache_s *)calloc(1, sizeof(struct SDCache_s));
334 if (sdl == NULL)
335 return NULL;
336
337 strcpy(sdl->bsdf.name, sdnam);
338 sdl->next = SDcacheList;
339 SDcacheList = sdl;
340
341 sdl->refcnt = 1;
342 return &sdl->bsdf;
343 }
344
345 /* Get loaded BSDF from cache (or load and cache it on first call) */
346 /* Report any problem to stderr and return NULL on failure */
347 const SDData *
348 SDcacheFile(const char *fname)
349 {
350 SDData *sd;
351 SDError ec;
352
353 if (fname == NULL || !*fname)
354 return NULL;
355 SDerrorDetail[0] = '\0';
356 if ((sd = SDgetCache(fname)) == NULL) {
357 SDreportEnglish(SDEmemory, stderr);
358 return NULL;
359 }
360 if (!SDisLoaded(sd) && (ec = SDloadFile(sd, fname))) {
361 SDreportEnglish(ec, stderr);
362 SDfreeCache(sd);
363 return NULL;
364 }
365 return sd;
366 }
367
368 /* Free a BSDF from our cache (clear all if NULL) */
369 void
370 SDfreeCache(const SDData *sd)
371 {
372 struct SDCache_s *sdl, *sdLast = NULL;
373
374 if (sd == NULL) { /* free entire list */
375 while ((sdl = SDcacheList) != NULL) {
376 SDcacheList = sdl->next;
377 SDfreeBSDF(&sdl->bsdf);
378 free(sdl);
379 }
380 return;
381 }
382 for (sdl = SDcacheList; sdl != NULL; sdl = (sdLast=sdl)->next)
383 if (&sdl->bsdf == sd)
384 break;
385 if (sdl == NULL || (sdl->refcnt -= (sdl->refcnt > 0)))
386 return; /* missing or still in use */
387 /* keep unreferenced data? */
388 if (SDisLoaded(sd) && SDretainSet) {
389 if (SDretainSet == SDretainAll)
390 return; /* keep everything */
391 /* else free cumulative data */
392 SDfreeCumulativeCache(sd->rf);
393 SDfreeCumulativeCache(sd->rb);
394 SDfreeCumulativeCache(sd->tf);
395 return;
396 }
397 /* remove from list and free */
398 if (sdLast == NULL)
399 SDcacheList = sdl->next;
400 else
401 sdLast->next = sdl->next;
402 SDfreeBSDF(&sdl->bsdf);
403 free(sdl);
404 }
405
406 /* Sample an individual BSDF component */
407 SDError
408 SDsampComponent(SDValue *sv, FVECT outVec, const FVECT inVec,
409 double randX, SDComponent *sdc)
410 {
411 float coef[SDmaxCh];
412 SDError ec;
413 const SDCDst *cd;
414 double d;
415 int n;
416 /* check arguments */
417 if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sdc == NULL))
418 return SDEargument;
419 /* get cumulative distribution */
420 cd = (*sdc->func->getCDist)(inVec, sdc);
421 if (cd == NULL)
422 return SDEmemory;
423 if (cd->cTotal <= 1e-7) { /* anything to sample? */
424 sv->spec = c_dfcolor;
425 sv->cieY = .0;
426 memset(outVec, 0, 3*sizeof(double));
427 return SDEnone;
428 }
429 sv->cieY = cd->cTotal;
430 /* compute sample direction */
431 ec = (*sdc->func->sampCDist)(outVec, randX, cd);
432 if (ec)
433 return ec;
434 /* get BSDF color */
435 n = (*sdc->func->getBSDFs)(coef, outVec, inVec, sdc->dist);
436 if (n <= 0) {
437 strcpy(SDerrorDetail, "BSDF sample value error");
438 return SDEinternal;
439 }
440 sv->spec = sdc->cspec[0];
441 d = coef[0];
442 while (--n) {
443 c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]);
444 d += coef[n];
445 }
446 /* make sure everything is set */
447 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
448 return SDEnone;
449 }
450
451 #define MS_MAXDIM 15
452
453 /* Convert 1-dimensional random variable to N-dimensional */
454 void
455 SDmultiSamp(double t[], int n, double randX)
456 {
457 unsigned nBits;
458 double scale;
459 bitmask_t ndx, coord[MS_MAXDIM];
460
461 while (n > MS_MAXDIM) /* punt for higher dimensions */
462 t[--n] = rand()*(1./(RAND_MAX+.5));
463 nBits = (8*sizeof(bitmask_t) - 1) / n;
464 ndx = randX * (double)((bitmask_t)1 << (nBits*n));
465 /* get coordinate on Hilbert curve */
466 hilbert_i2c(n, nBits, ndx, coord);
467 /* convert back to [0,1) range */
468 scale = 1. / (double)((bitmask_t)1 << nBits);
469 while (n--)
470 t[n] = scale * ((double)coord[n] + rand()*(1./(RAND_MAX+.5)));
471 }
472
473 #undef MS_MAXDIM
474
475 /* Generate diffuse hemispherical sample */
476 static void
477 SDdiffuseSamp(FVECT outVec, int outFront, double randX)
478 {
479 /* convert to position on hemisphere */
480 SDmultiSamp(outVec, 2, randX);
481 SDsquare2disk(outVec, outVec[0], outVec[1]);
482 outVec[2] = 1. - outVec[0]*outVec[0] - outVec[1]*outVec[1];
483 if (outVec[2] > .0) /* a bit of paranoia */
484 outVec[2] = sqrt(outVec[2]);
485 if (!outFront) /* going out back? */
486 outVec[2] = -outVec[2];
487 }
488
489 /* Query projected solid angle coverage for non-diffuse BSDF direction */
490 SDError
491 SDsizeBSDF(double *projSA, const FVECT vec, int qflags, const SDData *sd)
492 {
493 SDSpectralDF *rdf;
494 SDError ec;
495 int i;
496 /* check arguments */
497 if ((projSA == NULL) | (vec == NULL) | (sd == NULL))
498 return SDEargument;
499 /* initialize extrema */
500 switch (qflags) {
501 case SDqueryMax:
502 projSA[0] = .0;
503 break;
504 case SDqueryMin+SDqueryMax:
505 projSA[1] = .0;
506 /* fall through */
507 case SDqueryMin:
508 projSA[0] = 10.;
509 break;
510 case 0:
511 return SDEargument;
512 }
513 if (vec[2] > .0) /* front surface query? */
514 rdf = sd->rf;
515 else
516 rdf = sd->rb;
517 ec = SDEdata; /* run through components */
518 for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) {
519 ec = (*rdf->comp[i].func->queryProjSA)(projSA, vec, qflags,
520 rdf->comp[i].dist);
521 if (ec)
522 return ec;
523 }
524 for (i = (sd->tf==NULL) ? 0 : sd->tf->ncomp; i--; ) {
525 ec = (*sd->tf->comp[i].func->queryProjSA)(projSA, vec, qflags,
526 sd->tf->comp[i].dist);
527 if (ec)
528 return ec;
529 }
530 if (ec) { /* all diffuse? */
531 projSA[0] = M_PI;
532 if (qflags == SDqueryMin+SDqueryMax)
533 projSA[1] = M_PI;
534 }
535 return SDEnone;
536 }
537
538 /* Return BSDF for the given incident and scattered ray vectors */
539 SDError
540 SDevalBSDF(SDValue *sv, const FVECT outVec, const FVECT inVec, const SDData *sd)
541 {
542 int inFront, outFront;
543 SDSpectralDF *sdf;
544 float coef[SDmaxCh];
545 int nch, i;
546 /* check arguments */
547 if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL))
548 return SDEargument;
549 /* whose side are we on? */
550 inFront = (inVec[2] > .0);
551 outFront = (outVec[2] > .0);
552 /* start with diffuse portion */
553 if (inFront & outFront) {
554 *sv = sd->rLambFront;
555 sdf = sd->rf;
556 } else if (!(inFront | outFront)) {
557 *sv = sd->rLambBack;
558 sdf = sd->rb;
559 } else /* inFront ^ outFront */ {
560 *sv = sd->tLamb;
561 sdf = sd->tf;
562 }
563 sv->cieY *= 1./M_PI;
564 /* add non-diffuse components */
565 i = (sdf != NULL) ? sdf->ncomp : 0;
566 while (i-- > 0) {
567 nch = (*sdf->comp[i].func->getBSDFs)(coef, outVec, inVec,
568 sdf->comp[i].dist);
569 while (nch-- > 0) {
570 c_cmix(&sv->spec, sv->cieY, &sv->spec,
571 coef[nch], &sdf->comp[i].cspec[nch]);
572 sv->cieY += coef[nch];
573 }
574 }
575 /* make sure everything is set */
576 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
577 return SDEnone;
578 }
579
580 /* Compute directional hemispherical scattering at this incident angle */
581 double
582 SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd)
583 {
584 double hsum;
585 SDSpectralDF *rdf;
586 const SDCDst *cd;
587 int i;
588 /* check arguments */
589 if ((inVec == NULL) | (sd == NULL))
590 return .0;
591 /* gather diffuse components */
592 if (inVec[2] > .0) {
593 hsum = sd->rLambFront.cieY;
594 rdf = sd->rf;
595 } else /* !inFront */ {
596 hsum = sd->rLambBack.cieY;
597 rdf = sd->rb;
598 }
599 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
600 hsum = .0;
601 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
602 hsum += sd->tLamb.cieY;
603 /* gather non-diffuse components */
604 i = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
605 rdf != NULL) ? rdf->ncomp : 0;
606 while (i-- > 0) { /* non-diffuse reflection */
607 cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
608 if (cd != NULL)
609 hsum += cd->cTotal;
610 }
611 i = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
612 sd->tf != NULL) ? sd->tf->ncomp : 0;
613 while (i-- > 0) { /* non-diffuse transmission */
614 cd = (*sd->tf->comp[i].func->getCDist)(inVec, &sd->tf->comp[i]);
615 if (cd != NULL)
616 hsum += cd->cTotal;
617 }
618 return hsum;
619 }
620
621 /* Sample BSDF direction based on the given random variable */
622 SDError
623 SDsampBSDF(SDValue *sv, FVECT outVec, const FVECT inVec,
624 double randX, int sflags, const SDData *sd)
625 {
626 SDError ec;
627 int inFront;
628 SDSpectralDF *rdf;
629 double rdiff;
630 float coef[SDmaxCh];
631 int i, j, n, nr;
632 SDComponent *sdc;
633 const SDCDst **cdarr = NULL;
634 /* check arguments */
635 if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL) |
636 (randX < .0) | (randX >= 1.))
637 return SDEargument;
638 /* whose side are we on? */
639 inFront = (inVec[2] > .0);
640 /* remember diffuse portions */
641 if (inFront) {
642 *sv = sd->rLambFront;
643 rdf = sd->rf;
644 } else /* !inFront */ {
645 *sv = sd->rLambBack;
646 rdf = sd->rb;
647 }
648 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
649 sv->cieY = .0;
650 rdiff = sv->cieY;
651 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
652 sv->cieY += sd->tLamb.cieY;
653 /* gather non-diffuse components */
654 i = nr = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
655 rdf != NULL) ? rdf->ncomp : 0;
656 j = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
657 sd->tf != NULL) ? sd->tf->ncomp : 0;
658 n = i + j;
659 if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL)
660 return SDEmemory;
661 while (j-- > 0) { /* non-diffuse transmission */
662 cdarr[i+j] = (*sd->tf->comp[j].func->getCDist)(inVec, &sd->tf->comp[j]);
663 if (cdarr[i+j] == NULL) {
664 free(cdarr);
665 return SDEmemory;
666 }
667 sv->cieY += cdarr[i+j]->cTotal;
668 }
669 while (i-- > 0) { /* non-diffuse reflection */
670 cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
671 if (cdarr[i] == NULL) {
672 free(cdarr);
673 return SDEmemory;
674 }
675 sv->cieY += cdarr[i]->cTotal;
676 }
677 if (sv->cieY <= 1e-7) { /* anything to sample? */
678 sv->cieY = .0;
679 memset(outVec, 0, 3*sizeof(double));
680 return SDEnone;
681 }
682 /* scale random variable */
683 randX *= sv->cieY;
684 /* diffuse reflection? */
685 if (randX < rdiff) {
686 SDdiffuseSamp(outVec, inFront, randX/rdiff);
687 goto done;
688 }
689 randX -= rdiff;
690 /* diffuse transmission? */
691 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) {
692 if (randX < sd->tLamb.cieY) {
693 sv->spec = sd->tLamb.spec;
694 SDdiffuseSamp(outVec, !inFront, randX/sd->tLamb.cieY);
695 goto done;
696 }
697 randX -= sd->tLamb.cieY;
698 }
699 /* else one of cumulative dist. */
700 for (i = 0; i < n && randX < cdarr[i]->cTotal; i++)
701 randX -= cdarr[i]->cTotal;
702 if (i >= n)
703 return SDEinternal;
704 /* compute sample direction */
705 sdc = (i < nr) ? &rdf->comp[i] : &sd->tf->comp[i-nr];
706 ec = (*sdc->func->sampCDist)(outVec, randX/cdarr[i]->cTotal, cdarr[i]);
707 if (ec)
708 return ec;
709 /* compute color */
710 j = (*sdc->func->getBSDFs)(coef, outVec, inVec, sdc->dist);
711 if (j <= 0) {
712 sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error",
713 sd->name);
714 return SDEinternal;
715 }
716 sv->spec = sdc->cspec[0];
717 rdiff = coef[0];
718 while (--j) {
719 c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]);
720 rdiff += coef[j];
721 }
722 done:
723 if (cdarr != NULL)
724 free(cdarr);
725 /* make sure everything is set */
726 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
727 return SDEnone;
728 }
729
730 /* Compute World->BSDF transform from surface normal and up (Y) vector */
731 SDError
732 SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec)
733 {
734 if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL))
735 return SDEargument;
736 VCOPY(vMtx[2], sNrm);
737 if (normalize(vMtx[2]) == .0)
738 return SDEargument;
739 fcross(vMtx[0], uVec, vMtx[2]);
740 if (normalize(vMtx[0]) == .0)
741 return SDEargument;
742 fcross(vMtx[1], vMtx[2], vMtx[0]);
743 return SDEnone;
744 }
745
746 /* Compute inverse transform */
747 SDError
748 SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3])
749 {
750 RREAL mTmp[3][3];
751 double d;
752
753 if ((iMtx == NULL) | (vMtx == NULL))
754 return SDEargument;
755 /* compute determinant */
756 mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2];
757 mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1];
758 mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2];
759 d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2];
760 if (d == .0) {
761 strcpy(SDerrorDetail, "Zero determinant in matrix inversion");
762 return SDEargument;
763 }
764 d = 1./d; /* invert matrix */
765 mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d;
766 mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]);
767 mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]);
768 mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]);
769 mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]);
770 mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]);
771 mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]);
772 memcpy(iMtx, mTmp, sizeof(mTmp));
773 return SDEnone;
774 }
775
776 /* Transform and normalize direction (column) vector */
777 SDError
778 SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec)
779 {
780 FVECT vTmp;
781
782 if ((resVec == NULL) | (inpVec == NULL))
783 return SDEargument;
784 if (vMtx == NULL) { /* assume they just want to normalize */
785 if (resVec != inpVec)
786 VCOPY(resVec, inpVec);
787 return (normalize(resVec) > .0) ? SDEnone : SDEargument;
788 }
789 vTmp[0] = DOT(vMtx[0], inpVec);
790 vTmp[1] = DOT(vMtx[1], inpVec);
791 vTmp[2] = DOT(vMtx[2], inpVec);
792 if (normalize(vTmp) == .0)
793 return SDEargument;
794 VCOPY(resVec, vTmp);
795 return SDEnone;
796 }
797
798 /*################################################################*/
799 /*######### DEPRECATED ROUTINES AWAITING PERMANENT REMOVAL #######*/
800
801 /*
802 * Routines for handling BSDF data
803 */
804
805 #include "standard.h"
806 #include "paths.h"
807 #include <ctype.h>
808
809 #define MAXLATS 46 /* maximum number of latitudes */
810
811 /* BSDF angle specification */
812 typedef struct {
813 char name[64]; /* basis name */
814 int nangles; /* total number of directions */
815 struct {
816 float tmin; /* starting theta */
817 short nphis; /* number of phis (0 term) */
818 } lat[MAXLATS+1]; /* latitudes */
819 } ANGLE_BASIS;
820
821 #define MAXABASES 7 /* limit on defined bases */
822
823 static ANGLE_BASIS abase_list[MAXABASES] = {
824 {
825 "LBNL/Klems Full", 145,
826 { {-5., 1},
827 {5., 8},
828 {15., 16},
829 {25., 20},
830 {35., 24},
831 {45., 24},
832 {55., 24},
833 {65., 16},
834 {75., 12},
835 {90., 0} }
836 }, {
837 "LBNL/Klems Half", 73,
838 { {-6.5, 1},
839 {6.5, 8},
840 {19.5, 12},
841 {32.5, 16},
842 {46.5, 20},
843 {61.5, 12},
844 {76.5, 4},
845 {90., 0} }
846 }, {
847 "LBNL/Klems Quarter", 41,
848 { {-9., 1},
849 {9., 8},
850 {27., 12},
851 {46., 12},
852 {66., 8},
853 {90., 0} }
854 }
855 };
856
857 static int nabases = 3; /* current number of defined bases */
858
859 #define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6)
860
861 static int
862 fequal(double a, double b)
863 {
864 if (b != .0)
865 a = a/b - 1.;
866 return((a <= 1e-6) & (a >= -1e-6));
867 }
868
869 /* Returns the name of the given tag */
870 #ifdef ezxml_name
871 #undef ezxml_name
872 static char *
873 ezxml_name(ezxml_t xml)
874 {
875 if (xml == NULL)
876 return(NULL);
877 return(xml->name);
878 }
879 #endif
880
881 /* Returns the given tag's character content or empty string if none */
882 #ifdef ezxml_txt
883 #undef ezxml_txt
884 static char *
885 ezxml_txt(ezxml_t xml)
886 {
887 if (xml == NULL)
888 return("");
889 return(xml->txt);
890 }
891 #endif
892
893
894 static int
895 ab_getvec( /* get vector for this angle basis index */
896 FVECT v,
897 int ndx,
898 void *p
899 )
900 {
901 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
902 int li;
903 double pol, azi, d;
904
905 if ((ndx < 0) | (ndx >= ab->nangles))
906 return(0);
907 for (li = 0; ndx >= ab->lat[li].nphis; li++)
908 ndx -= ab->lat[li].nphis;
909 pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin);
910 azi = 2.*PI*ndx/ab->lat[li].nphis;
911 v[2] = d = cos(pol);
912 d = sqrt(1. - d*d); /* sin(pol) */
913 v[0] = cos(azi)*d;
914 v[1] = sin(azi)*d;
915 return(1);
916 }
917
918
919 static int
920 ab_getndx( /* get index corresponding to the given vector */
921 FVECT v,
922 void *p
923 )
924 {
925 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
926 int li, ndx;
927 double pol, azi, d;
928
929 if ((v[2] < -1.0) | (v[2] > 1.0))
930 return(-1);
931 pol = 180.0/PI*acos(v[2]);
932 azi = 180.0/PI*atan2(v[1], v[0]);
933 if (azi < 0.0) azi += 360.0;
934 for (li = 1; ab->lat[li].tmin <= pol; li++)
935 if (!ab->lat[li].nphis)
936 return(-1);
937 --li;
938 ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5);
939 if (ndx >= ab->lat[li].nphis) ndx = 0;
940 while (li--)
941 ndx += ab->lat[li].nphis;
942 return(ndx);
943 }
944
945
946 static double
947 ab_getohm( /* get solid angle for this angle basis index */
948 int ndx,
949 void *p
950 )
951 {
952 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
953 int li;
954 double theta, theta1;
955
956 if ((ndx < 0) | (ndx >= ab->nangles))
957 return(0);
958 for (li = 0; ndx >= ab->lat[li].nphis; li++)
959 ndx -= ab->lat[li].nphis;
960 theta1 = PI/180. * ab->lat[li+1].tmin;
961 if (ab->lat[li].nphis == 1) { /* special case */
962 if (ab->lat[li].tmin > FTINY)
963 error(USER, "unsupported BSDF coordinate system");
964 return(2.*PI*(1. - cos(theta1)));
965 }
966 theta = PI/180. * ab->lat[li].tmin;
967 return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis);
968 }
969
970
971 static int
972 ab_getvecR( /* get reverse vector for this angle basis index */
973 FVECT v,
974 int ndx,
975 void *p
976 )
977 {
978 if (!ab_getvec(v, ndx, p))
979 return(0);
980
981 v[0] = -v[0];
982 v[1] = -v[1];
983 v[2] = -v[2];
984
985 return(1);
986 }
987
988
989 static int
990 ab_getndxR( /* get index corresponding to the reverse vector */
991 FVECT v,
992 void *p
993 )
994 {
995 FVECT v2;
996
997 v2[0] = -v[0];
998 v2[1] = -v[1];
999 v2[2] = -v[2];
1000
1001 return ab_getndx(v2, p);
1002 }
1003
1004
1005 static void
1006 load_angle_basis( /* load custom BSDF angle basis */
1007 ezxml_t wab
1008 )
1009 {
1010 char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName"));
1011 ezxml_t wbb;
1012 int i;
1013
1014 if (!abname || !*abname)
1015 return;
1016 for (i = nabases; i--; )
1017 if (!strcasecmp(abname, abase_list[i].name))
1018 return; /* assume it's the same */
1019 if (nabases >= MAXABASES)
1020 error(INTERNAL, "too many angle bases");
1021 strcpy(abase_list[nabases].name, abname);
1022 abase_list[nabases].nangles = 0;
1023 for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock");
1024 wbb != NULL; i++, wbb = wbb->next) {
1025 if (i >= MAXLATS)
1026 error(INTERNAL, "too many latitudes in custom basis");
1027 abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt(
1028 ezxml_child(ezxml_child(wbb,
1029 "ThetaBounds"), "UpperTheta")));
1030 if (!i)
1031 abase_list[nabases].lat[i].tmin =
1032 -abase_list[nabases].lat[i+1].tmin;
1033 else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb,
1034 "ThetaBounds"), "LowerTheta"))),
1035 abase_list[nabases].lat[i].tmin))
1036 error(WARNING, "theta values disagree in custom basis");
1037 abase_list[nabases].nangles +=
1038 abase_list[nabases].lat[i].nphis =
1039 atoi(ezxml_txt(ezxml_child(wbb, "nPhis")));
1040 }
1041 abase_list[nabases++].lat[i].nphis = 0;
1042 }
1043
1044
1045 static void
1046 load_geometry( /* load geometric dimensions and description (if any) */
1047 struct BSDF_data *dp,
1048 ezxml_t wdb
1049 )
1050 {
1051 ezxml_t geom;
1052 double cfact;
1053 const char *fmt, *mgfstr;
1054
1055 dp->dim[0] = dp->dim[1] = dp->dim[2] = 0;
1056 dp->mgf = NULL;
1057 if ((geom = ezxml_child(wdb, "Width")) != NULL)
1058 dp->dim[0] = atof(ezxml_txt(geom)) *
1059 to_meters(ezxml_attr(geom, "unit"));
1060 if ((geom = ezxml_child(wdb, "Height")) != NULL)
1061 dp->dim[1] = atof(ezxml_txt(geom)) *
1062 to_meters(ezxml_attr(geom, "unit"));
1063 if ((geom = ezxml_child(wdb, "Thickness")) != NULL)
1064 dp->dim[2] = atof(ezxml_txt(geom)) *
1065 to_meters(ezxml_attr(geom, "unit"));
1066 if ((geom = ezxml_child(wdb, "Geometry")) == NULL ||
1067 (mgfstr = ezxml_txt(geom)) == NULL)
1068 return;
1069 if ((fmt = ezxml_attr(geom, "format")) != NULL &&
1070 strcasecmp(fmt, "MGF")) {
1071 sprintf(errmsg, "unrecognized geometry format '%s'", fmt);
1072 error(WARNING, errmsg);
1073 return;
1074 }
1075 cfact = to_meters(ezxml_attr(geom, "unit"));
1076 dp->mgf = (char *)malloc(strlen(mgfstr)+32);
1077 if (dp->mgf == NULL)
1078 error(SYSTEM, "out of memory in load_geometry");
1079 if (cfact < 0.99 || cfact > 1.01)
1080 sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr);
1081 else
1082 strcpy(dp->mgf, mgfstr);
1083 }
1084
1085
1086 static void
1087 load_bsdf_data( /* load BSDF distribution for this wavelength */
1088 struct BSDF_data *dp,
1089 ezxml_t wdb
1090 )
1091 {
1092 char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis"));
1093 char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis"));
1094 char *sdata;
1095 int i;
1096
1097 if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) {
1098 error(WARNING, "missing column/row basis for BSDF");
1099 return;
1100 }
1101 for (i = nabases; i--; )
1102 if (!strcasecmp(cbasis, abase_list[i].name)) {
1103 dp->ninc = abase_list[i].nangles;
1104 dp->ib_priv = (void *)&abase_list[i];
1105 dp->ib_vec = ab_getvecR;
1106 dp->ib_ndx = ab_getndxR;
1107 dp->ib_ohm = ab_getohm;
1108 break;
1109 }
1110 if (i < 0) {
1111 sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis);
1112 error(WARNING, errmsg);
1113 return;
1114 }
1115 for (i = nabases; i--; )
1116 if (!strcasecmp(rbasis, abase_list[i].name)) {
1117 dp->nout = abase_list[i].nangles;
1118 dp->ob_priv = (void *)&abase_list[i];
1119 dp->ob_vec = ab_getvec;
1120 dp->ob_ndx = ab_getndx;
1121 dp->ob_ohm = ab_getohm;
1122 break;
1123 }
1124 if (i < 0) {
1125 sprintf(errmsg, "undefined RowAngleBasis '%s'", rbasis);
1126 error(WARNING, errmsg);
1127 return;
1128 }
1129 /* read BSDF data */
1130 sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData"));
1131 if (!sdata || !*sdata) {
1132 error(WARNING, "missing BSDF ScatteringData");
1133 return;
1134 }
1135 dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout);
1136 if (dp->bsdf == NULL)
1137 error(SYSTEM, "out of memory in load_bsdf_data");
1138 for (i = 0; i < dp->ninc*dp->nout; i++) {
1139 char *sdnext = fskip(sdata);
1140 if (sdnext == NULL) {
1141 error(WARNING, "bad/missing BSDF ScatteringData");
1142 free(dp->bsdf); dp->bsdf = NULL;
1143 return;
1144 }
1145 while (*sdnext && isspace(*sdnext))
1146 sdnext++;
1147 if (*sdnext == ',') sdnext++;
1148 dp->bsdf[i] = atof(sdata);
1149 sdata = sdnext;
1150 }
1151 while (isspace(*sdata))
1152 sdata++;
1153 if (*sdata) {
1154 sprintf(errmsg, "%d extra characters after BSDF ScatteringData",
1155 (int)strlen(sdata));
1156 error(WARNING, errmsg);
1157 }
1158 }
1159
1160
1161 static int
1162 check_bsdf_data( /* check that BSDF data is sane */
1163 struct BSDF_data *dp
1164 )
1165 {
1166 double *omega_iarr, *omega_oarr;
1167 double dom, contrib, hemi_total, full_total;
1168 int nneg;
1169 FVECT v;
1170 int i, o;
1171
1172 if (dp == NULL || dp->bsdf == NULL)
1173 return(0);
1174 omega_iarr = (double *)calloc(dp->ninc, sizeof(double));
1175 omega_oarr = (double *)calloc(dp->nout, sizeof(double));
1176 if ((omega_iarr == NULL) | (omega_oarr == NULL))
1177 error(SYSTEM, "out of memory in check_bsdf_data");
1178 /* incoming projected solid angles */
1179 hemi_total = .0;
1180 for (i = dp->ninc; i--; ) {
1181 dom = getBSDF_incohm(dp,i);
1182 if (dom <= .0) {
1183 error(WARNING, "zero/negative incoming solid angle");
1184 continue;
1185 }
1186 if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) {
1187 error(WARNING, "illegal incoming BSDF direction");
1188 free(omega_iarr); free(omega_oarr);
1189 return(0);
1190 }
1191 hemi_total += omega_iarr[i] = dom * -v[2];
1192 }
1193 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1194 sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%",
1195 100.*(hemi_total/PI - 1.));
1196 error(WARNING, errmsg);
1197 }
1198 dom = PI / hemi_total; /* fix normalization */
1199 for (i = dp->ninc; i--; )
1200 omega_iarr[i] *= dom;
1201 /* outgoing projected solid angles */
1202 hemi_total = .0;
1203 for (o = dp->nout; o--; ) {
1204 dom = getBSDF_outohm(dp,o);
1205 if (dom <= .0) {
1206 error(WARNING, "zero/negative outgoing solid angle");
1207 continue;
1208 }
1209 if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) {
1210 error(WARNING, "illegal outgoing BSDF direction");
1211 free(omega_iarr); free(omega_oarr);
1212 return(0);
1213 }
1214 hemi_total += omega_oarr[o] = dom * v[2];
1215 }
1216 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1217 sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%",
1218 100.*(hemi_total/PI - 1.));
1219 error(WARNING, errmsg);
1220 }
1221 dom = PI / hemi_total; /* fix normalization */
1222 for (o = dp->nout; o--; )
1223 omega_oarr[o] *= dom;
1224 nneg = 0; /* check outgoing totals */
1225 for (i = 0; i < dp->ninc; i++) {
1226 hemi_total = .0;
1227 for (o = dp->nout; o--; ) {
1228 double f = BSDF_value(dp,i,o);
1229 if (f >= .0)
1230 hemi_total += f*omega_oarr[o];
1231 else {
1232 nneg += (f < -FTINY);
1233 BSDF_value(dp,i,o) = .0f;
1234 }
1235 }
1236 if (hemi_total > 1.01) {
1237 sprintf(errmsg,
1238 "incoming BSDF direction %d passes %.1f%% of light",
1239 i, 100.*hemi_total);
1240 error(WARNING, errmsg);
1241 }
1242 }
1243 if (nneg) {
1244 sprintf(errmsg, "%d negative BSDF values (ignored)", nneg);
1245 error(WARNING, errmsg);
1246 }
1247 full_total = .0; /* reverse roles and check again */
1248 for (o = 0; o < dp->nout; o++) {
1249 hemi_total = .0;
1250 for (i = dp->ninc; i--; )
1251 hemi_total += BSDF_value(dp,i,o) * omega_iarr[i];
1252
1253 if (hemi_total > 1.01) {
1254 sprintf(errmsg,
1255 "outgoing BSDF direction %d collects %.1f%% of light",
1256 o, 100.*hemi_total);
1257 error(WARNING, errmsg);
1258 }
1259 full_total += hemi_total*omega_oarr[o];
1260 }
1261 full_total /= PI;
1262 if (full_total > 1.00001) {
1263 sprintf(errmsg, "BSDF transfers %.4f%% of light",
1264 100.*full_total);
1265 error(WARNING, errmsg);
1266 }
1267 free(omega_iarr); free(omega_oarr);
1268 return(1);
1269 }
1270
1271
1272 struct BSDF_data *
1273 load_BSDF( /* load BSDF data from file */
1274 char *fname
1275 )
1276 {
1277 char *path;
1278 ezxml_t fl, wtl, wld, wdb;
1279 struct BSDF_data *dp;
1280
1281 path = getpath(fname, getrlibpath(), R_OK);
1282 if (path == NULL) {
1283 sprintf(errmsg, "cannot find BSDF file \"%s\"", fname);
1284 error(WARNING, errmsg);
1285 return(NULL);
1286 }
1287 fl = ezxml_parse_file(path);
1288 if (fl == NULL) {
1289 sprintf(errmsg, "cannot open BSDF \"%s\"", path);
1290 error(WARNING, errmsg);
1291 return(NULL);
1292 }
1293 if (ezxml_error(fl)[0]) {
1294 sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl));
1295 error(WARNING, errmsg);
1296 ezxml_free(fl);
1297 return(NULL);
1298 }
1299 if (strcmp(ezxml_name(fl), "WindowElement")) {
1300 sprintf(errmsg,
1301 "BSDF \"%s\": top level node not 'WindowElement'",
1302 path);
1303 error(WARNING, errmsg);
1304 ezxml_free(fl);
1305 return(NULL);
1306 }
1307 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
1308 if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl,
1309 "DataDefinition"), "IncidentDataStructure")),
1310 "Columns")) {
1311 sprintf(errmsg,
1312 "BSDF \"%s\": unsupported IncidentDataStructure",
1313 path);
1314 error(WARNING, errmsg);
1315 ezxml_free(fl);
1316 return(NULL);
1317 }
1318 load_angle_basis(ezxml_child(ezxml_child(wtl,
1319 "DataDefinition"), "AngleBasis"));
1320 dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data));
1321 load_geometry(dp, ezxml_child(wtl, "Material"));
1322 for (wld = ezxml_child(wtl, "WavelengthData");
1323 wld != NULL; wld = wld->next) {
1324 if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")),
1325 "Visible"))
1326 continue;
1327 for (wdb = ezxml_child(wld, "WavelengthDataBlock");
1328 wdb != NULL; wdb = wdb->next)
1329 if (!strcasecmp(ezxml_txt(ezxml_child(wdb,
1330 "WavelengthDataDirection")),
1331 "Transmission Front"))
1332 break;
1333 if (wdb != NULL) { /* load front BTDF */
1334 load_bsdf_data(dp, wdb);
1335 break; /* ignore the rest */
1336 }
1337 }
1338 ezxml_free(fl); /* done with XML file */
1339 if (!check_bsdf_data(dp)) {
1340 sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path);
1341 error(WARNING, errmsg);
1342 free_BSDF(dp);
1343 dp = NULL;
1344 }
1345 return(dp);
1346 }
1347
1348
1349 void
1350 free_BSDF( /* free BSDF data structure */
1351 struct BSDF_data *b
1352 )
1353 {
1354 if (b == NULL)
1355 return;
1356 if (b->mgf != NULL)
1357 free(b->mgf);
1358 if (b->bsdf != NULL)
1359 free(b->bsdf);
1360 free(b);
1361 }
1362
1363
1364 int
1365 r_BSDF_incvec( /* compute random input vector at given location */
1366 FVECT v,
1367 struct BSDF_data *b,
1368 int i,
1369 double rv,
1370 MAT4 xm
1371 )
1372 {
1373 FVECT pert;
1374 double rad;
1375 int j;
1376
1377 if (!getBSDF_incvec(v, b, i))
1378 return(0);
1379 rad = sqrt(getBSDF_incohm(b, i) / PI);
1380 multisamp(pert, 3, rv);
1381 for (j = 0; j < 3; j++)
1382 v[j] += rad*(2.*pert[j] - 1.);
1383 if (xm != NULL)
1384 multv3(v, v, xm);
1385 return(normalize(v) != 0.0);
1386 }
1387
1388
1389 int
1390 r_BSDF_outvec( /* compute random output vector at given location */
1391 FVECT v,
1392 struct BSDF_data *b,
1393 int o,
1394 double rv,
1395 MAT4 xm
1396 )
1397 {
1398 FVECT pert;
1399 double rad;
1400 int j;
1401
1402 if (!getBSDF_outvec(v, b, o))
1403 return(0);
1404 rad = sqrt(getBSDF_outohm(b, o) / PI);
1405 multisamp(pert, 3, rv);
1406 for (j = 0; j < 3; j++)
1407 v[j] += rad*(2.*pert[j] - 1.);
1408 if (xm != NULL)
1409 multv3(v, v, xm);
1410 return(normalize(v) != 0.0);
1411 }
1412
1413
1414 static int
1415 addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
1416 char *xfarg[],
1417 FVECT xp,
1418 FVECT yp,
1419 FVECT zp
1420 )
1421 {
1422 static char bufs[3][16];
1423 int bn = 0;
1424 char **xfp = xfarg;
1425 double theta;
1426
1427 if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) {
1428 /* Special case for X' along Z-axis */
1429 theta = -atan2(yp[0], yp[1]);
1430 *xfp++ = "-ry";
1431 *xfp++ = xp[2] < 0.0 ? "90" : "-90";
1432 *xfp++ = "-rz";
1433 sprintf(bufs[bn], "%f", theta*(180./PI));
1434 *xfp++ = bufs[bn++];
1435 return(xfp - xfarg);
1436 }
1437 theta = atan2(yp[2], zp[2]);
1438 if (!FEQ(theta,0.0)) {
1439 *xfp++ = "-rx";
1440 sprintf(bufs[bn], "%f", theta*(180./PI));
1441 *xfp++ = bufs[bn++];
1442 }
1443 theta = asin(-xp[2]);
1444 if (!FEQ(theta,0.0)) {
1445 *xfp++ = "-ry";
1446 sprintf(bufs[bn], " %f", theta*(180./PI));
1447 *xfp++ = bufs[bn++];
1448 }
1449 theta = atan2(xp[1], xp[0]);
1450 if (!FEQ(theta,0.0)) {
1451 *xfp++ = "-rz";
1452 sprintf(bufs[bn], "%f", theta*(180./PI));
1453 *xfp++ = bufs[bn++];
1454 }
1455 *xfp = NULL;
1456 return(xfp - xfarg);
1457 }
1458
1459
1460 int
1461 getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */
1462 MAT4 xm,
1463 FVECT nrm,
1464 UpDir ud,
1465 char *xfbuf
1466 )
1467 {
1468 char *xfargs[7];
1469 XF myxf;
1470 FVECT updir, xdest, ydest;
1471 int i;
1472
1473 updir[0] = updir[1] = updir[2] = 0.;
1474 switch (ud) {
1475 case UDzneg:
1476 updir[2] = -1.;
1477 break;
1478 case UDyneg:
1479 updir[1] = -1.;
1480 break;
1481 case UDxneg:
1482 updir[0] = -1.;
1483 break;
1484 case UDxpos:
1485 updir[0] = 1.;
1486 break;
1487 case UDypos:
1488 updir[1] = 1.;
1489 break;
1490 case UDzpos:
1491 updir[2] = 1.;
1492 break;
1493 case UDunknown:
1494 return(0);
1495 }
1496 fcross(xdest, updir, nrm);
1497 if (normalize(xdest) == 0.0)
1498 return(0);
1499 fcross(ydest, nrm, xdest);
1500 xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs);
1501 copymat4(xm, myxf.xfm);
1502 if (xfbuf == NULL)
1503 return(1);
1504 /* return xf arguments as well */
1505 for (i = 0; xfargs[i] != NULL; i++) {
1506 *xfbuf++ = ' ';
1507 strcpy(xfbuf, xfargs[i]);
1508 while (*xfbuf) ++xfbuf;
1509 }
1510 return(1);
1511 }
1512
1513 /*######### END DEPRECATED ROUTINES #######*/
1514 /*################################################################*/