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root/radiance/ray/src/common/bsdf.c
Revision: 2.25
Committed: Sun Apr 24 20:16:52 2011 UTC (13 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.24: +6 -6 lines
Log Message:
Bug fixes to last change

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdf.c,v 2.24 2011/04/24 19:39:21 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 ioVec, double randX, SDComponent *sdc)
409 {
410 float coef[SDmaxCh];
411 SDError ec;
412 FVECT inVec;
413 const SDCDst *cd;
414 double d;
415 int n;
416 /* check arguments */
417 if ((sv == NULL) | (ioVec == NULL) | (sdc == NULL))
418 return SDEargument;
419 /* get cumulative distribution */
420 VCOPY(inVec, ioVec);
421 cd = (*sdc->func->getCDist)(inVec, sdc);
422 if (cd == NULL)
423 return SDEmemory;
424 if (cd->cTotal <= 1e-7) { /* anything to sample? */
425 sv->spec = c_dfcolor;
426 sv->cieY = .0;
427 memset(ioVec, 0, 3*sizeof(double));
428 return SDEnone;
429 }
430 sv->cieY = cd->cTotal;
431 /* compute sample direction */
432 ec = (*sdc->func->sampCDist)(ioVec, randX, cd);
433 if (ec)
434 return ec;
435 /* get BSDF color */
436 n = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc);
437 if (n <= 0) {
438 strcpy(SDerrorDetail, "BSDF sample value error");
439 return SDEinternal;
440 }
441 sv->spec = sdc->cspec[0];
442 d = coef[0];
443 while (--n) {
444 c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]);
445 d += coef[n];
446 }
447 /* make sure everything is set */
448 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
449 return SDEnone;
450 }
451
452 #define MS_MAXDIM 15
453
454 /* Convert 1-dimensional random variable to N-dimensional */
455 void
456 SDmultiSamp(double t[], int n, double randX)
457 {
458 unsigned nBits;
459 double scale;
460 bitmask_t ndx, coord[MS_MAXDIM];
461
462 while (n > MS_MAXDIM) /* punt for higher dimensions */
463 t[--n] = rand()*(1./(RAND_MAX+.5));
464 nBits = (8*sizeof(bitmask_t) - 1) / n;
465 ndx = randX * (double)((bitmask_t)1 << (nBits*n));
466 /* get coordinate on Hilbert curve */
467 hilbert_i2c(n, nBits, ndx, coord);
468 /* convert back to [0,1) range */
469 scale = 1. / (double)((bitmask_t)1 << nBits);
470 while (n--)
471 t[n] = scale * ((double)coord[n] + rand()*(1./(RAND_MAX+.5)));
472 }
473
474 #undef MS_MAXDIM
475
476 /* Generate diffuse hemispherical sample */
477 static void
478 SDdiffuseSamp(FVECT outVec, int outFront, double randX)
479 {
480 /* convert to position on hemisphere */
481 SDmultiSamp(outVec, 2, randX);
482 SDsquare2disk(outVec, outVec[0], outVec[1]);
483 outVec[2] = 1. - outVec[0]*outVec[0] - outVec[1]*outVec[1];
484 if (outVec[2] > 0) /* a bit of paranoia */
485 outVec[2] = sqrt(outVec[2]);
486 if (!outFront) /* going out back? */
487 outVec[2] = -outVec[2];
488 }
489
490 /* Query projected solid angle coverage for non-diffuse BSDF direction */
491 SDError
492 SDsizeBSDF(double *projSA, const FVECT v1, const RREAL *v2,
493 int qflags, const SDData *sd)
494 {
495 SDSpectralDF *rdf, *tdf;
496 SDError ec;
497 int i;
498 /* check arguments */
499 if ((projSA == NULL) | (v1 == NULL))
500 return SDEargument;
501 /* initialize extrema */
502 switch (qflags) {
503 case SDqueryMax:
504 projSA[0] = .0;
505 break;
506 case SDqueryMin+SDqueryMax:
507 projSA[1] = .0;
508 /* fall through */
509 case SDqueryMin:
510 projSA[0] = 10.;
511 break;
512 case 0:
513 return SDEargument;
514 }
515 if (v1[2] > 0) /* front surface query? */
516 rdf = sd->rf;
517 else
518 rdf = sd->rb;
519 tdf = NULL; /* transmitted component? */
520 if (v2 != NULL && v1[2] > 0 ^ v2[2] > 0) {
521 rdf = NULL;
522 tdf = sd->tf;
523 }
524 ec = SDEdata; /* run through components */
525 for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) {
526 ec = (*rdf->comp[i].func->queryProjSA)(projSA, v1, v2,
527 qflags, &rdf->comp[i]);
528 if (ec)
529 return ec;
530 }
531 for (i = (tdf==NULL) ? 0 : tdf->ncomp; i--; ) {
532 ec = (*tdf->comp[i].func->queryProjSA)(projSA, v1, v2,
533 qflags, &tdf->comp[i]);
534 if (ec)
535 return ec;
536 }
537 if (ec) { /* all diffuse? */
538 projSA[0] = M_PI;
539 if (qflags == SDqueryMin+SDqueryMax)
540 projSA[1] = M_PI;
541 }
542 return SDEnone;
543 }
544
545 /* Return BSDF for the given incident and scattered ray vectors */
546 SDError
547 SDevalBSDF(SDValue *sv, const FVECT outVec, const FVECT inVec, const SDData *sd)
548 {
549 int inFront, outFront;
550 SDSpectralDF *sdf;
551 float coef[SDmaxCh];
552 int nch, i;
553 /* check arguments */
554 if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL))
555 return SDEargument;
556 /* whose side are we on? */
557 inFront = (inVec[2] > 0);
558 outFront = (outVec[2] > 0);
559 /* start with diffuse portion */
560 if (inFront & outFront) {
561 *sv = sd->rLambFront;
562 sdf = sd->rf;
563 } else if (!(inFront | outFront)) {
564 *sv = sd->rLambBack;
565 sdf = sd->rb;
566 } else /* inFront ^ outFront */ {
567 *sv = sd->tLamb;
568 sdf = sd->tf;
569 }
570 sv->cieY *= 1./M_PI;
571 /* add non-diffuse components */
572 i = (sdf != NULL) ? sdf->ncomp : 0;
573 while (i-- > 0) {
574 nch = (*sdf->comp[i].func->getBSDFs)(coef, outVec, inVec,
575 &sdf->comp[i]);
576 while (nch-- > 0) {
577 c_cmix(&sv->spec, sv->cieY, &sv->spec,
578 coef[nch], &sdf->comp[i].cspec[nch]);
579 sv->cieY += coef[nch];
580 }
581 }
582 /* make sure everything is set */
583 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
584 return SDEnone;
585 }
586
587 /* Compute directional hemispherical scattering at this incident angle */
588 double
589 SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd)
590 {
591 double hsum;
592 SDSpectralDF *rdf;
593 const SDCDst *cd;
594 int i;
595 /* check arguments */
596 if ((inVec == NULL) | (sd == NULL))
597 return .0;
598 /* gather diffuse components */
599 if (inVec[2] > 0) {
600 hsum = sd->rLambFront.cieY;
601 rdf = sd->rf;
602 } else /* !inFront */ {
603 hsum = sd->rLambBack.cieY;
604 rdf = sd->rb;
605 }
606 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
607 hsum = .0;
608 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
609 hsum += sd->tLamb.cieY;
610 /* gather non-diffuse components */
611 i = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
612 rdf != NULL) ? rdf->ncomp : 0;
613 while (i-- > 0) { /* non-diffuse reflection */
614 cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
615 if (cd != NULL)
616 hsum += cd->cTotal;
617 }
618 i = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
619 sd->tf != NULL) ? sd->tf->ncomp : 0;
620 while (i-- > 0) { /* non-diffuse transmission */
621 cd = (*sd->tf->comp[i].func->getCDist)(inVec, &sd->tf->comp[i]);
622 if (cd != NULL)
623 hsum += cd->cTotal;
624 }
625 return hsum;
626 }
627
628 /* Sample BSDF direction based on the given random variable */
629 SDError
630 SDsampBSDF(SDValue *sv, FVECT ioVec, double randX, int sflags, const SDData *sd)
631 {
632 SDError ec;
633 FVECT inVec;
634 int inFront;
635 SDSpectralDF *rdf;
636 double rdiff;
637 float coef[SDmaxCh];
638 int i, j, n, nr;
639 SDComponent *sdc;
640 const SDCDst **cdarr = NULL;
641 /* check arguments */
642 if ((sv == NULL) | (ioVec == NULL) | (sd == NULL) |
643 (randX < 0) | (randX >= 1.))
644 return SDEargument;
645 /* whose side are we on? */
646 VCOPY(inVec, ioVec);
647 inFront = (inVec[2] > 0);
648 /* remember diffuse portions */
649 if (inFront) {
650 *sv = sd->rLambFront;
651 rdf = sd->rf;
652 } else /* !inFront */ {
653 *sv = sd->rLambBack;
654 rdf = sd->rb;
655 }
656 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
657 sv->cieY = .0;
658 rdiff = sv->cieY;
659 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
660 sv->cieY += sd->tLamb.cieY;
661 /* gather non-diffuse components */
662 i = nr = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
663 rdf != NULL) ? rdf->ncomp : 0;
664 j = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
665 sd->tf != NULL) ? sd->tf->ncomp : 0;
666 n = i + j;
667 if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL)
668 return SDEmemory;
669 while (j-- > 0) { /* non-diffuse transmission */
670 cdarr[i+j] = (*sd->tf->comp[j].func->getCDist)(inVec, &sd->tf->comp[j]);
671 if (cdarr[i+j] == NULL) {
672 free(cdarr);
673 return SDEmemory;
674 }
675 sv->cieY += cdarr[i+j]->cTotal;
676 }
677 while (i-- > 0) { /* non-diffuse reflection */
678 cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
679 if (cdarr[i] == NULL) {
680 free(cdarr);
681 return SDEmemory;
682 }
683 sv->cieY += cdarr[i]->cTotal;
684 }
685 if (sv->cieY <= 1e-7) { /* anything to sample? */
686 sv->cieY = .0;
687 memset(ioVec, 0, 3*sizeof(double));
688 return SDEnone;
689 }
690 /* scale random variable */
691 randX *= sv->cieY;
692 /* diffuse reflection? */
693 if (randX < rdiff) {
694 SDdiffuseSamp(ioVec, inFront, randX/rdiff);
695 goto done;
696 }
697 randX -= rdiff;
698 /* diffuse transmission? */
699 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) {
700 if (randX < sd->tLamb.cieY) {
701 sv->spec = sd->tLamb.spec;
702 SDdiffuseSamp(ioVec, !inFront, randX/sd->tLamb.cieY);
703 goto done;
704 }
705 randX -= sd->tLamb.cieY;
706 }
707 /* else one of cumulative dist. */
708 for (i = 0; i < n && randX < cdarr[i]->cTotal; i++)
709 randX -= cdarr[i]->cTotal;
710 if (i >= n)
711 return SDEinternal;
712 /* compute sample direction */
713 sdc = (i < nr) ? &rdf->comp[i] : &sd->tf->comp[i-nr];
714 ec = (*sdc->func->sampCDist)(ioVec, randX/cdarr[i]->cTotal, cdarr[i]);
715 if (ec)
716 return ec;
717 /* compute color */
718 j = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc);
719 if (j <= 0) {
720 sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error",
721 sd->name);
722 return SDEinternal;
723 }
724 sv->spec = sdc->cspec[0];
725 rdiff = coef[0];
726 while (--j) {
727 c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]);
728 rdiff += coef[j];
729 }
730 done:
731 if (cdarr != NULL)
732 free(cdarr);
733 /* make sure everything is set */
734 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
735 return SDEnone;
736 }
737
738 /* Compute World->BSDF transform from surface normal and up (Y) vector */
739 SDError
740 SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec)
741 {
742 if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL))
743 return SDEargument;
744 VCOPY(vMtx[2], sNrm);
745 if (normalize(vMtx[2]) == 0)
746 return SDEargument;
747 fcross(vMtx[0], uVec, vMtx[2]);
748 if (normalize(vMtx[0]) == 0)
749 return SDEargument;
750 fcross(vMtx[1], vMtx[2], vMtx[0]);
751 return SDEnone;
752 }
753
754 /* Compute inverse transform */
755 SDError
756 SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3])
757 {
758 RREAL mTmp[3][3];
759 double d;
760
761 if ((iMtx == NULL) | (vMtx == NULL))
762 return SDEargument;
763 /* compute determinant */
764 mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2];
765 mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1];
766 mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2];
767 d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2];
768 if (d == 0) {
769 strcpy(SDerrorDetail, "Zero determinant in matrix inversion");
770 return SDEargument;
771 }
772 d = 1./d; /* invert matrix */
773 mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d;
774 mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]);
775 mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]);
776 mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]);
777 mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]);
778 mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]);
779 mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]);
780 memcpy(iMtx, mTmp, sizeof(mTmp));
781 return SDEnone;
782 }
783
784 /* Transform and normalize direction (column) vector */
785 SDError
786 SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec)
787 {
788 FVECT vTmp;
789
790 if ((resVec == NULL) | (inpVec == NULL))
791 return SDEargument;
792 if (vMtx == NULL) { /* assume they just want to normalize */
793 if (resVec != inpVec)
794 VCOPY(resVec, inpVec);
795 return (normalize(resVec) > 0) ? SDEnone : SDEargument;
796 }
797 vTmp[0] = DOT(vMtx[0], inpVec);
798 vTmp[1] = DOT(vMtx[1], inpVec);
799 vTmp[2] = DOT(vMtx[2], inpVec);
800 if (normalize(vTmp) == 0)
801 return SDEargument;
802 VCOPY(resVec, vTmp);
803 return SDEnone;
804 }
805
806 /*################################################################*/
807 /*######### DEPRECATED ROUTINES AWAITING PERMANENT REMOVAL #######*/
808
809 /*
810 * Routines for handling BSDF data
811 */
812
813 #include "standard.h"
814 #include "paths.h"
815 #include <ctype.h>
816
817 #define MAXLATS 46 /* maximum number of latitudes */
818
819 /* BSDF angle specification */
820 typedef struct {
821 char name[64]; /* basis name */
822 int nangles; /* total number of directions */
823 struct {
824 float tmin; /* starting theta */
825 short nphis; /* number of phis (0 term) */
826 } lat[MAXLATS+1]; /* latitudes */
827 } ANGLE_BASIS;
828
829 #define MAXABASES 7 /* limit on defined bases */
830
831 static ANGLE_BASIS abase_list[MAXABASES] = {
832 {
833 "LBNL/Klems Full", 145,
834 { {-5., 1},
835 {5., 8},
836 {15., 16},
837 {25., 20},
838 {35., 24},
839 {45., 24},
840 {55., 24},
841 {65., 16},
842 {75., 12},
843 {90., 0} }
844 }, {
845 "LBNL/Klems Half", 73,
846 { {-6.5, 1},
847 {6.5, 8},
848 {19.5, 12},
849 {32.5, 16},
850 {46.5, 20},
851 {61.5, 12},
852 {76.5, 4},
853 {90., 0} }
854 }, {
855 "LBNL/Klems Quarter", 41,
856 { {-9., 1},
857 {9., 8},
858 {27., 12},
859 {46., 12},
860 {66., 8},
861 {90., 0} }
862 }
863 };
864
865 static int nabases = 3; /* current number of defined bases */
866
867 #define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6)
868
869 static int
870 fequal(double a, double b)
871 {
872 if (b != 0)
873 a = a/b - 1.;
874 return((a <= 1e-6) & (a >= -1e-6));
875 }
876
877 /* Returns the name of the given tag */
878 #ifdef ezxml_name
879 #undef ezxml_name
880 static char *
881 ezxml_name(ezxml_t xml)
882 {
883 if (xml == NULL)
884 return(NULL);
885 return(xml->name);
886 }
887 #endif
888
889 /* Returns the given tag's character content or empty string if none */
890 #ifdef ezxml_txt
891 #undef ezxml_txt
892 static char *
893 ezxml_txt(ezxml_t xml)
894 {
895 if (xml == NULL)
896 return("");
897 return(xml->txt);
898 }
899 #endif
900
901
902 static int
903 ab_getvec( /* get vector for this angle basis index */
904 FVECT v,
905 int ndx,
906 void *p
907 )
908 {
909 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
910 int li;
911 double pol, azi, d;
912
913 if ((ndx < 0) | (ndx >= ab->nangles))
914 return(0);
915 for (li = 0; ndx >= ab->lat[li].nphis; li++)
916 ndx -= ab->lat[li].nphis;
917 pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin);
918 azi = 2.*PI*ndx/ab->lat[li].nphis;
919 v[2] = d = cos(pol);
920 d = sqrt(1. - d*d); /* sin(pol) */
921 v[0] = cos(azi)*d;
922 v[1] = sin(azi)*d;
923 return(1);
924 }
925
926
927 static int
928 ab_getndx( /* get index corresponding to the given vector */
929 FVECT v,
930 void *p
931 )
932 {
933 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
934 int li, ndx;
935 double pol, azi, d;
936
937 if ((v[2] < -1.0) | (v[2] > 1.0))
938 return(-1);
939 pol = 180.0/PI*acos(v[2]);
940 azi = 180.0/PI*atan2(v[1], v[0]);
941 if (azi < 0.0) azi += 360.0;
942 for (li = 1; ab->lat[li].tmin <= pol; li++)
943 if (!ab->lat[li].nphis)
944 return(-1);
945 --li;
946 ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5);
947 if (ndx >= ab->lat[li].nphis) ndx = 0;
948 while (li--)
949 ndx += ab->lat[li].nphis;
950 return(ndx);
951 }
952
953
954 static double
955 ab_getohm( /* get solid angle for this angle basis index */
956 int ndx,
957 void *p
958 )
959 {
960 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
961 int li;
962 double theta, theta1;
963
964 if ((ndx < 0) | (ndx >= ab->nangles))
965 return(0);
966 for (li = 0; ndx >= ab->lat[li].nphis; li++)
967 ndx -= ab->lat[li].nphis;
968 theta1 = PI/180. * ab->lat[li+1].tmin;
969 if (ab->lat[li].nphis == 1) { /* special case */
970 if (ab->lat[li].tmin > FTINY)
971 error(USER, "unsupported BSDF coordinate system");
972 return(2.*PI*(1. - cos(theta1)));
973 }
974 theta = PI/180. * ab->lat[li].tmin;
975 return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis);
976 }
977
978
979 static int
980 ab_getvecR( /* get reverse vector for this angle basis index */
981 FVECT v,
982 int ndx,
983 void *p
984 )
985 {
986 if (!ab_getvec(v, ndx, p))
987 return(0);
988
989 v[0] = -v[0];
990 v[1] = -v[1];
991 v[2] = -v[2];
992
993 return(1);
994 }
995
996
997 static int
998 ab_getndxR( /* get index corresponding to the reverse vector */
999 FVECT v,
1000 void *p
1001 )
1002 {
1003 FVECT v2;
1004
1005 v2[0] = -v[0];
1006 v2[1] = -v[1];
1007 v2[2] = -v[2];
1008
1009 return ab_getndx(v2, p);
1010 }
1011
1012
1013 static void
1014 load_angle_basis( /* load custom BSDF angle basis */
1015 ezxml_t wab
1016 )
1017 {
1018 char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName"));
1019 ezxml_t wbb;
1020 int i;
1021
1022 if (!abname || !*abname)
1023 return;
1024 for (i = nabases; i--; )
1025 if (!strcasecmp(abname, abase_list[i].name))
1026 return; /* assume it's the same */
1027 if (nabases >= MAXABASES)
1028 error(INTERNAL, "too many angle bases");
1029 strcpy(abase_list[nabases].name, abname);
1030 abase_list[nabases].nangles = 0;
1031 for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock");
1032 wbb != NULL; i++, wbb = wbb->next) {
1033 if (i >= MAXLATS)
1034 error(INTERNAL, "too many latitudes in custom basis");
1035 abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt(
1036 ezxml_child(ezxml_child(wbb,
1037 "ThetaBounds"), "UpperTheta")));
1038 if (!i)
1039 abase_list[nabases].lat[i].tmin =
1040 -abase_list[nabases].lat[i+1].tmin;
1041 else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb,
1042 "ThetaBounds"), "LowerTheta"))),
1043 abase_list[nabases].lat[i].tmin))
1044 error(WARNING, "theta values disagree in custom basis");
1045 abase_list[nabases].nangles +=
1046 abase_list[nabases].lat[i].nphis =
1047 atoi(ezxml_txt(ezxml_child(wbb, "nPhis")));
1048 }
1049 abase_list[nabases++].lat[i].nphis = 0;
1050 }
1051
1052
1053 static void
1054 load_geometry( /* load geometric dimensions and description (if any) */
1055 struct BSDF_data *dp,
1056 ezxml_t wdb
1057 )
1058 {
1059 ezxml_t geom;
1060 double cfact;
1061 const char *fmt, *mgfstr;
1062
1063 dp->dim[0] = dp->dim[1] = dp->dim[2] = 0;
1064 dp->mgf = NULL;
1065 if ((geom = ezxml_child(wdb, "Width")) != NULL)
1066 dp->dim[0] = atof(ezxml_txt(geom)) *
1067 to_meters(ezxml_attr(geom, "unit"));
1068 if ((geom = ezxml_child(wdb, "Height")) != NULL)
1069 dp->dim[1] = atof(ezxml_txt(geom)) *
1070 to_meters(ezxml_attr(geom, "unit"));
1071 if ((geom = ezxml_child(wdb, "Thickness")) != NULL)
1072 dp->dim[2] = atof(ezxml_txt(geom)) *
1073 to_meters(ezxml_attr(geom, "unit"));
1074 if ((geom = ezxml_child(wdb, "Geometry")) == NULL ||
1075 (mgfstr = ezxml_txt(geom)) == NULL)
1076 return;
1077 if ((fmt = ezxml_attr(geom, "format")) != NULL &&
1078 strcasecmp(fmt, "MGF")) {
1079 sprintf(errmsg, "unrecognized geometry format '%s'", fmt);
1080 error(WARNING, errmsg);
1081 return;
1082 }
1083 cfact = to_meters(ezxml_attr(geom, "unit"));
1084 dp->mgf = (char *)malloc(strlen(mgfstr)+32);
1085 if (dp->mgf == NULL)
1086 error(SYSTEM, "out of memory in load_geometry");
1087 if (cfact < 0.99 || cfact > 1.01)
1088 sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr);
1089 else
1090 strcpy(dp->mgf, mgfstr);
1091 }
1092
1093
1094 static void
1095 load_bsdf_data( /* load BSDF distribution for this wavelength */
1096 struct BSDF_data *dp,
1097 ezxml_t wdb
1098 )
1099 {
1100 char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis"));
1101 char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis"));
1102 char *sdata;
1103 int i;
1104
1105 if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) {
1106 error(WARNING, "missing column/row basis for BSDF");
1107 return;
1108 }
1109 for (i = nabases; i--; )
1110 if (!strcasecmp(cbasis, abase_list[i].name)) {
1111 dp->ninc = abase_list[i].nangles;
1112 dp->ib_priv = (void *)&abase_list[i];
1113 dp->ib_vec = ab_getvecR;
1114 dp->ib_ndx = ab_getndxR;
1115 dp->ib_ohm = ab_getohm;
1116 break;
1117 }
1118 if (i < 0) {
1119 sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis);
1120 error(WARNING, errmsg);
1121 return;
1122 }
1123 for (i = nabases; i--; )
1124 if (!strcasecmp(rbasis, abase_list[i].name)) {
1125 dp->nout = abase_list[i].nangles;
1126 dp->ob_priv = (void *)&abase_list[i];
1127 dp->ob_vec = ab_getvec;
1128 dp->ob_ndx = ab_getndx;
1129 dp->ob_ohm = ab_getohm;
1130 break;
1131 }
1132 if (i < 0) {
1133 sprintf(errmsg, "undefined RowAngleBasis '%s'", rbasis);
1134 error(WARNING, errmsg);
1135 return;
1136 }
1137 /* read BSDF data */
1138 sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData"));
1139 if (!sdata || !*sdata) {
1140 error(WARNING, "missing BSDF ScatteringData");
1141 return;
1142 }
1143 dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout);
1144 if (dp->bsdf == NULL)
1145 error(SYSTEM, "out of memory in load_bsdf_data");
1146 for (i = 0; i < dp->ninc*dp->nout; i++) {
1147 char *sdnext = fskip(sdata);
1148 if (sdnext == NULL) {
1149 error(WARNING, "bad/missing BSDF ScatteringData");
1150 free(dp->bsdf); dp->bsdf = NULL;
1151 return;
1152 }
1153 while (*sdnext && isspace(*sdnext))
1154 sdnext++;
1155 if (*sdnext == ',') sdnext++;
1156 dp->bsdf[i] = atof(sdata);
1157 sdata = sdnext;
1158 }
1159 while (isspace(*sdata))
1160 sdata++;
1161 if (*sdata) {
1162 sprintf(errmsg, "%d extra characters after BSDF ScatteringData",
1163 (int)strlen(sdata));
1164 error(WARNING, errmsg);
1165 }
1166 }
1167
1168
1169 static int
1170 check_bsdf_data( /* check that BSDF data is sane */
1171 struct BSDF_data *dp
1172 )
1173 {
1174 double *omega_iarr, *omega_oarr;
1175 double dom, contrib, hemi_total, full_total;
1176 int nneg;
1177 FVECT v;
1178 int i, o;
1179
1180 if (dp == NULL || dp->bsdf == NULL)
1181 return(0);
1182 omega_iarr = (double *)calloc(dp->ninc, sizeof(double));
1183 omega_oarr = (double *)calloc(dp->nout, sizeof(double));
1184 if ((omega_iarr == NULL) | (omega_oarr == NULL))
1185 error(SYSTEM, "out of memory in check_bsdf_data");
1186 /* incoming projected solid angles */
1187 hemi_total = .0;
1188 for (i = dp->ninc; i--; ) {
1189 dom = getBSDF_incohm(dp,i);
1190 if (dom <= 0) {
1191 error(WARNING, "zero/negative incoming solid angle");
1192 continue;
1193 }
1194 if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) {
1195 error(WARNING, "illegal incoming BSDF direction");
1196 free(omega_iarr); free(omega_oarr);
1197 return(0);
1198 }
1199 hemi_total += omega_iarr[i] = dom * -v[2];
1200 }
1201 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1202 sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%",
1203 100.*(hemi_total/PI - 1.));
1204 error(WARNING, errmsg);
1205 }
1206 dom = PI / hemi_total; /* fix normalization */
1207 for (i = dp->ninc; i--; )
1208 omega_iarr[i] *= dom;
1209 /* outgoing projected solid angles */
1210 hemi_total = .0;
1211 for (o = dp->nout; o--; ) {
1212 dom = getBSDF_outohm(dp,o);
1213 if (dom <= 0) {
1214 error(WARNING, "zero/negative outgoing solid angle");
1215 continue;
1216 }
1217 if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) {
1218 error(WARNING, "illegal outgoing BSDF direction");
1219 free(omega_iarr); free(omega_oarr);
1220 return(0);
1221 }
1222 hemi_total += omega_oarr[o] = dom * v[2];
1223 }
1224 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1225 sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%",
1226 100.*(hemi_total/PI - 1.));
1227 error(WARNING, errmsg);
1228 }
1229 dom = PI / hemi_total; /* fix normalization */
1230 for (o = dp->nout; o--; )
1231 omega_oarr[o] *= dom;
1232 nneg = 0; /* check outgoing totals */
1233 for (i = 0; i < dp->ninc; i++) {
1234 hemi_total = .0;
1235 for (o = dp->nout; o--; ) {
1236 double f = BSDF_value(dp,i,o);
1237 if (f >= 0)
1238 hemi_total += f*omega_oarr[o];
1239 else {
1240 nneg += (f < -FTINY);
1241 BSDF_value(dp,i,o) = .0f;
1242 }
1243 }
1244 if (hemi_total > 1.01) {
1245 sprintf(errmsg,
1246 "incoming BSDF direction %d passes %.1f%% of light",
1247 i, 100.*hemi_total);
1248 error(WARNING, errmsg);
1249 }
1250 }
1251 if (nneg) {
1252 sprintf(errmsg, "%d negative BSDF values (ignored)", nneg);
1253 error(WARNING, errmsg);
1254 }
1255 full_total = .0; /* reverse roles and check again */
1256 for (o = 0; o < dp->nout; o++) {
1257 hemi_total = .0;
1258 for (i = dp->ninc; i--; )
1259 hemi_total += BSDF_value(dp,i,o) * omega_iarr[i];
1260
1261 if (hemi_total > 1.01) {
1262 sprintf(errmsg,
1263 "outgoing BSDF direction %d collects %.1f%% of light",
1264 o, 100.*hemi_total);
1265 error(WARNING, errmsg);
1266 }
1267 full_total += hemi_total*omega_oarr[o];
1268 }
1269 full_total /= PI;
1270 if (full_total > 1.00001) {
1271 sprintf(errmsg, "BSDF transfers %.4f%% of light",
1272 100.*full_total);
1273 error(WARNING, errmsg);
1274 }
1275 free(omega_iarr); free(omega_oarr);
1276 return(1);
1277 }
1278
1279
1280 struct BSDF_data *
1281 load_BSDF( /* load BSDF data from file */
1282 char *fname
1283 )
1284 {
1285 char *path;
1286 ezxml_t fl, wtl, wld, wdb;
1287 struct BSDF_data *dp;
1288
1289 path = getpath(fname, getrlibpath(), R_OK);
1290 if (path == NULL) {
1291 sprintf(errmsg, "cannot find BSDF file \"%s\"", fname);
1292 error(WARNING, errmsg);
1293 return(NULL);
1294 }
1295 fl = ezxml_parse_file(path);
1296 if (fl == NULL) {
1297 sprintf(errmsg, "cannot open BSDF \"%s\"", path);
1298 error(WARNING, errmsg);
1299 return(NULL);
1300 }
1301 if (ezxml_error(fl)[0]) {
1302 sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl));
1303 error(WARNING, errmsg);
1304 ezxml_free(fl);
1305 return(NULL);
1306 }
1307 if (strcmp(ezxml_name(fl), "WindowElement")) {
1308 sprintf(errmsg,
1309 "BSDF \"%s\": top level node not 'WindowElement'",
1310 path);
1311 error(WARNING, errmsg);
1312 ezxml_free(fl);
1313 return(NULL);
1314 }
1315 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
1316 if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl,
1317 "DataDefinition"), "IncidentDataStructure")),
1318 "Columns")) {
1319 sprintf(errmsg,
1320 "BSDF \"%s\": unsupported IncidentDataStructure",
1321 path);
1322 error(WARNING, errmsg);
1323 ezxml_free(fl);
1324 return(NULL);
1325 }
1326 load_angle_basis(ezxml_child(ezxml_child(wtl,
1327 "DataDefinition"), "AngleBasis"));
1328 dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data));
1329 load_geometry(dp, ezxml_child(wtl, "Material"));
1330 for (wld = ezxml_child(wtl, "WavelengthData");
1331 wld != NULL; wld = wld->next) {
1332 if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")),
1333 "Visible"))
1334 continue;
1335 for (wdb = ezxml_child(wld, "WavelengthDataBlock");
1336 wdb != NULL; wdb = wdb->next)
1337 if (!strcasecmp(ezxml_txt(ezxml_child(wdb,
1338 "WavelengthDataDirection")),
1339 "Transmission Front"))
1340 break;
1341 if (wdb != NULL) { /* load front BTDF */
1342 load_bsdf_data(dp, wdb);
1343 break; /* ignore the rest */
1344 }
1345 }
1346 ezxml_free(fl); /* done with XML file */
1347 if (!check_bsdf_data(dp)) {
1348 sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path);
1349 error(WARNING, errmsg);
1350 free_BSDF(dp);
1351 dp = NULL;
1352 }
1353 return(dp);
1354 }
1355
1356
1357 void
1358 free_BSDF( /* free BSDF data structure */
1359 struct BSDF_data *b
1360 )
1361 {
1362 if (b == NULL)
1363 return;
1364 if (b->mgf != NULL)
1365 free(b->mgf);
1366 if (b->bsdf != NULL)
1367 free(b->bsdf);
1368 free(b);
1369 }
1370
1371
1372 int
1373 r_BSDF_incvec( /* compute random input vector at given location */
1374 FVECT v,
1375 struct BSDF_data *b,
1376 int i,
1377 double rv,
1378 MAT4 xm
1379 )
1380 {
1381 FVECT pert;
1382 double rad;
1383 int j;
1384
1385 if (!getBSDF_incvec(v, b, i))
1386 return(0);
1387 rad = sqrt(getBSDF_incohm(b, i) / PI);
1388 multisamp(pert, 3, rv);
1389 for (j = 0; j < 3; j++)
1390 v[j] += rad*(2.*pert[j] - 1.);
1391 if (xm != NULL)
1392 multv3(v, v, xm);
1393 return(normalize(v) != 0.0);
1394 }
1395
1396
1397 int
1398 r_BSDF_outvec( /* compute random output vector at given location */
1399 FVECT v,
1400 struct BSDF_data *b,
1401 int o,
1402 double rv,
1403 MAT4 xm
1404 )
1405 {
1406 FVECT pert;
1407 double rad;
1408 int j;
1409
1410 if (!getBSDF_outvec(v, b, o))
1411 return(0);
1412 rad = sqrt(getBSDF_outohm(b, o) / PI);
1413 multisamp(pert, 3, rv);
1414 for (j = 0; j < 3; j++)
1415 v[j] += rad*(2.*pert[j] - 1.);
1416 if (xm != NULL)
1417 multv3(v, v, xm);
1418 return(normalize(v) != 0.0);
1419 }
1420
1421
1422 static int
1423 addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
1424 char *xfarg[],
1425 FVECT xp,
1426 FVECT yp,
1427 FVECT zp
1428 )
1429 {
1430 static char bufs[3][16];
1431 int bn = 0;
1432 char **xfp = xfarg;
1433 double theta;
1434
1435 if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) {
1436 /* Special case for X' along Z-axis */
1437 theta = -atan2(yp[0], yp[1]);
1438 *xfp++ = "-ry";
1439 *xfp++ = xp[2] < 0.0 ? "90" : "-90";
1440 *xfp++ = "-rz";
1441 sprintf(bufs[bn], "%f", theta*(180./PI));
1442 *xfp++ = bufs[bn++];
1443 return(xfp - xfarg);
1444 }
1445 theta = atan2(yp[2], zp[2]);
1446 if (!FEQ(theta,0.0)) {
1447 *xfp++ = "-rx";
1448 sprintf(bufs[bn], "%f", theta*(180./PI));
1449 *xfp++ = bufs[bn++];
1450 }
1451 theta = asin(-xp[2]);
1452 if (!FEQ(theta,0.0)) {
1453 *xfp++ = "-ry";
1454 sprintf(bufs[bn], " %f", theta*(180./PI));
1455 *xfp++ = bufs[bn++];
1456 }
1457 theta = atan2(xp[1], xp[0]);
1458 if (!FEQ(theta,0.0)) {
1459 *xfp++ = "-rz";
1460 sprintf(bufs[bn], "%f", theta*(180./PI));
1461 *xfp++ = bufs[bn++];
1462 }
1463 *xfp = NULL;
1464 return(xfp - xfarg);
1465 }
1466
1467
1468 int
1469 getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */
1470 MAT4 xm,
1471 FVECT nrm,
1472 UpDir ud,
1473 char *xfbuf
1474 )
1475 {
1476 char *xfargs[7];
1477 XF myxf;
1478 FVECT updir, xdest, ydest;
1479 int i;
1480
1481 updir[0] = updir[1] = updir[2] = 0.;
1482 switch (ud) {
1483 case UDzneg:
1484 updir[2] = -1.;
1485 break;
1486 case UDyneg:
1487 updir[1] = -1.;
1488 break;
1489 case UDxneg:
1490 updir[0] = -1.;
1491 break;
1492 case UDxpos:
1493 updir[0] = 1.;
1494 break;
1495 case UDypos:
1496 updir[1] = 1.;
1497 break;
1498 case UDzpos:
1499 updir[2] = 1.;
1500 break;
1501 case UDunknown:
1502 return(0);
1503 }
1504 fcross(xdest, updir, nrm);
1505 if (normalize(xdest) == 0.0)
1506 return(0);
1507 fcross(ydest, nrm, xdest);
1508 xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs);
1509 copymat4(xm, myxf.xfm);
1510 if (xfbuf == NULL)
1511 return(1);
1512 /* return xf arguments as well */
1513 for (i = 0; xfargs[i] != NULL; i++) {
1514 *xfbuf++ = ' ';
1515 strcpy(xfbuf, xfargs[i]);
1516 while (*xfbuf) ++xfbuf;
1517 }
1518 return(1);
1519 }
1520
1521 /*######### END DEPRECATED ROUTINES #######*/
1522 /*################################################################*/