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root/radiance/ray/src/common/bsdf.c
Revision: 2.33
Committed: Tue Jun 28 21:11:04 2011 UTC (12 years, 10 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.32: +3 -3 lines
Log Message:
Minor compile fixes

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdf.c,v 2.32 2011/06/23 16:00:37 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 #define _USE_MATH_DEFINES
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <math.h>
18 #include <ctype.h>
19 #include "ezxml.h"
20 #include "hilbert.h"
21 #include "bsdf.h"
22 #include "bsdf_m.h"
23 #include "bsdf_t.h"
24
25 /* English ASCII strings corresponding to ennumerated errors */
26 const char *SDerrorEnglish[] = {
27 "No error",
28 "Memory error",
29 "File input/output error",
30 "File format error",
31 "Illegal argument",
32 "Invalid data",
33 "Unsupported feature",
34 "Internal program error",
35 "Unknown error"
36 };
37
38 /* Additional information on last error (ASCII English) */
39 char SDerrorDetail[256];
40
41 /* Cache of loaded BSDFs */
42 struct SDCache_s *SDcacheList = NULL;
43
44 /* Retain BSDFs in cache list */
45 int SDretainSet = SDretainNone;
46
47 /* Report any error to the indicated stream (in English) */
48 SDError
49 SDreportEnglish(SDError ec, FILE *fp)
50 {
51 if (!ec)
52 return SDEnone;
53 if ((ec < SDEnone) | (ec > SDEunknown)) {
54 SDerrorDetail[0] = '\0';
55 ec = SDEunknown;
56 }
57 if (fp == NULL)
58 return ec;
59 fputs(SDerrorEnglish[ec], fp);
60 if (SDerrorDetail[0]) {
61 fputs(": ", fp);
62 fputs(SDerrorDetail, fp);
63 }
64 fputc('\n', fp);
65 if (fp != stderr)
66 fflush(fp);
67 return ec;
68 }
69
70 static double
71 to_meters( /* return factor to convert given unit to meters */
72 const char *unit
73 )
74 {
75 if (unit == NULL) return(1.); /* safe assumption? */
76 if (!strcasecmp(unit, "Meter")) return(1.);
77 if (!strcasecmp(unit, "Foot")) return(.3048);
78 if (!strcasecmp(unit, "Inch")) return(.0254);
79 if (!strcasecmp(unit, "Centimeter")) return(.01);
80 if (!strcasecmp(unit, "Millimeter")) return(.001);
81 sprintf(SDerrorDetail, "Unknown dimensional unit '%s'", unit);
82 return(-1.);
83 }
84
85 /* Load geometric dimensions and description (if any) */
86 static SDError
87 SDloadGeometry(SDData *sd, ezxml_t wdb)
88 {
89 ezxml_t geom;
90 double cfact;
91 const char *fmt, *mgfstr;
92
93 if (wdb == NULL) /* no geometry section? */
94 return SDEnone;
95 sd->dim[0] = sd->dim[1] = sd->dim[2] = .0;
96 if ((geom = ezxml_child(wdb, "Width")) != NULL)
97 sd->dim[0] = atof(ezxml_txt(geom)) *
98 to_meters(ezxml_attr(geom, "unit"));
99 if ((geom = ezxml_child(wdb, "Height")) != NULL)
100 sd->dim[1] = atof(ezxml_txt(geom)) *
101 to_meters(ezxml_attr(geom, "unit"));
102 if ((geom = ezxml_child(wdb, "Thickness")) != NULL)
103 sd->dim[2] = atof(ezxml_txt(geom)) *
104 to_meters(ezxml_attr(geom, "unit"));
105 if ((sd->dim[0] < 0) | (sd->dim[1] < 0) | (sd->dim[2] < 0)) {
106 sprintf(SDerrorDetail, "Negative size in \"%s\"", sd->name);
107 return SDEdata;
108 }
109 if ((geom = ezxml_child(wdb, "Geometry")) == NULL ||
110 (mgfstr = ezxml_txt(geom)) == NULL)
111 return SDEnone;
112 while (isspace(*mgfstr))
113 ++mgfstr;
114 if (!*mgfstr)
115 return SDEnone;
116 if ((fmt = ezxml_attr(geom, "format")) != NULL &&
117 strcasecmp(fmt, "MGF")) {
118 sprintf(SDerrorDetail,
119 "Unrecognized geometry format '%s' in \"%s\"",
120 fmt, sd->name);
121 return SDEsupport;
122 }
123 cfact = to_meters(ezxml_attr(geom, "unit"));
124 sd->mgf = (char *)malloc(strlen(mgfstr)+32);
125 if (sd->mgf == NULL) {
126 strcpy(SDerrorDetail, "Out of memory in SDloadGeometry");
127 return SDEmemory;
128 }
129 if (cfact < 0.99 || cfact > 1.01)
130 sprintf(sd->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr);
131 else
132 strcpy(sd->mgf, mgfstr);
133 return SDEnone;
134 }
135
136 /* Load a BSDF struct from the given file (free first and keep name) */
137 SDError
138 SDloadFile(SDData *sd, const char *fname)
139 {
140 SDError lastErr;
141 ezxml_t fl, wtl;
142
143 if ((sd == NULL) | (fname == NULL || !*fname))
144 return SDEargument;
145 /* free old data, keeping name */
146 SDfreeBSDF(sd);
147 /* parse XML file */
148 fl = ezxml_parse_file(fname);
149 if (fl == NULL) {
150 sprintf(SDerrorDetail, "Cannot open BSDF \"%s\"", fname);
151 return SDEfile;
152 }
153 if (ezxml_error(fl)[0]) {
154 sprintf(SDerrorDetail, "BSDF \"%s\" %s", fname, ezxml_error(fl));
155 ezxml_free(fl);
156 return SDEformat;
157 }
158 if (strcmp(ezxml_name(fl), "WindowElement")) {
159 sprintf(SDerrorDetail,
160 "BSDF \"%s\": top level node not 'WindowElement'",
161 sd->name);
162 ezxml_free(fl);
163 return SDEformat;
164 }
165 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
166 if (wtl == NULL) {
167 sprintf(SDerrorDetail, "BSDF \"%s\": no optical layer'",
168 sd->name);
169 ezxml_free(fl);
170 return SDEformat;
171 }
172 /* load geometry if present */
173 lastErr = SDloadGeometry(sd, ezxml_child(wtl, "Material"));
174 if (lastErr)
175 return lastErr;
176 /* try loading variable resolution data */
177 lastErr = SDloadTre(sd, wtl);
178 /* check our result */
179 if (lastErr == SDEsupport) /* try matrix BSDF if not tree data */
180 lastErr = SDloadMtx(sd, wtl);
181
182 /* done with XML file */
183 ezxml_free(fl);
184
185 if (lastErr) { /* was there a load error? */
186 SDfreeBSDF(sd);
187 return lastErr;
188 }
189 /* remove any insignificant components */
190 if (sd->rf != NULL && sd->rf->maxHemi <= .001) {
191 SDfreeSpectralDF(sd->rf); sd->rf = NULL;
192 }
193 if (sd->rb != NULL && sd->rb->maxHemi <= .001) {
194 SDfreeSpectralDF(sd->rb); sd->rb = NULL;
195 }
196 if (sd->tf != NULL && sd->tf->maxHemi <= .001) {
197 SDfreeSpectralDF(sd->tf); sd->tf = NULL;
198 }
199 /* return success */
200 return SDEnone;
201 }
202
203 /* Allocate new spectral distribution function */
204 SDSpectralDF *
205 SDnewSpectralDF(int nc)
206 {
207 SDSpectralDF *df;
208
209 if (nc <= 0) {
210 strcpy(SDerrorDetail, "Zero component spectral DF request");
211 return NULL;
212 }
213 df = (SDSpectralDF *)malloc(sizeof(SDSpectralDF) +
214 (nc-1)*sizeof(SDComponent));
215 if (df == NULL) {
216 sprintf(SDerrorDetail,
217 "Cannot allocate %d component spectral DF", nc);
218 return NULL;
219 }
220 df->minProjSA = .0;
221 df->maxHemi = .0;
222 df->ncomp = nc;
223 memset(df->comp, 0, nc*sizeof(SDComponent));
224 return df;
225 }
226
227 /* Free cached cumulative distributions for BSDF component */
228 void
229 SDfreeCumulativeCache(SDSpectralDF *df)
230 {
231 int n;
232 SDCDst *cdp;
233
234 if (df == NULL)
235 return;
236 for (n = df->ncomp; n-- > 0; )
237 while ((cdp = df->comp[n].cdList) != NULL) {
238 df->comp[n].cdList = cdp->next;
239 free(cdp);
240 }
241 }
242
243 /* Free a spectral distribution function */
244 void
245 SDfreeSpectralDF(SDSpectralDF *df)
246 {
247 int n;
248
249 if (df == NULL)
250 return;
251 SDfreeCumulativeCache(df);
252 for (n = df->ncomp; n-- > 0; )
253 (*df->comp[n].func->freeSC)(df->comp[n].dist);
254 free(df);
255 }
256
257 /* Shorten file path to useable BSDF name, removing suffix */
258 void
259 SDclipName(char *res, const char *fname)
260 {
261 const char *cp, *dot = NULL;
262
263 for (cp = fname; *cp; cp++)
264 if (*cp == '.')
265 dot = cp;
266 if ((dot == NULL) | (dot < fname+2))
267 dot = cp;
268 if (dot - fname >= SDnameLn)
269 fname = dot - SDnameLn + 1;
270 while (fname < dot)
271 *res++ = *fname++;
272 *res = '\0';
273 }
274
275 /* Initialize an unused BSDF struct (simply clears to zeroes) */
276 void
277 SDclearBSDF(SDData *sd, const char *fname)
278 {
279 if (sd == NULL)
280 return;
281 memset(sd, 0, sizeof(SDData));
282 if (fname == NULL)
283 return;
284 SDclipName(sd->name, fname);
285 }
286
287 /* Free data associated with BSDF struct */
288 void
289 SDfreeBSDF(SDData *sd)
290 {
291 if (sd == NULL)
292 return;
293 if (sd->mgf != NULL) {
294 free(sd->mgf);
295 sd->mgf = NULL;
296 }
297 if (sd->rf != NULL) {
298 SDfreeSpectralDF(sd->rf);
299 sd->rf = NULL;
300 }
301 if (sd->rb != NULL) {
302 SDfreeSpectralDF(sd->rb);
303 sd->rb = NULL;
304 }
305 if (sd->tf != NULL) {
306 SDfreeSpectralDF(sd->tf);
307 sd->tf = NULL;
308 }
309 sd->rLambFront.cieY = .0;
310 sd->rLambFront.spec.flags = 0;
311 sd->rLambBack.cieY = .0;
312 sd->rLambBack.spec.flags = 0;
313 sd->tLamb.cieY = .0;
314 sd->tLamb.spec.flags = 0;
315 }
316
317 /* Find writeable BSDF by name, or allocate new cache entry if absent */
318 SDData *
319 SDgetCache(const char *bname)
320 {
321 struct SDCache_s *sdl;
322 char sdnam[SDnameLn];
323
324 if (bname == NULL)
325 return NULL;
326
327 SDclipName(sdnam, bname);
328 for (sdl = SDcacheList; sdl != NULL; sdl = sdl->next)
329 if (!strcmp(sdl->bsdf.name, sdnam)) {
330 sdl->refcnt++;
331 return &sdl->bsdf;
332 }
333
334 sdl = (struct SDCache_s *)calloc(1, sizeof(struct SDCache_s));
335 if (sdl == NULL)
336 return NULL;
337
338 strcpy(sdl->bsdf.name, sdnam);
339 sdl->next = SDcacheList;
340 SDcacheList = sdl;
341
342 sdl->refcnt = 1;
343 return &sdl->bsdf;
344 }
345
346 /* Get loaded BSDF from cache (or load and cache it on first call) */
347 /* Report any problem to stderr and return NULL on failure */
348 const SDData *
349 SDcacheFile(const char *fname)
350 {
351 SDData *sd;
352 SDError ec;
353
354 if (fname == NULL || !*fname)
355 return NULL;
356 SDerrorDetail[0] = '\0';
357 if ((sd = SDgetCache(fname)) == NULL) {
358 SDreportEnglish(SDEmemory, stderr);
359 return NULL;
360 }
361 if (!SDisLoaded(sd) && (ec = SDloadFile(sd, fname))) {
362 SDreportEnglish(ec, stderr);
363 SDfreeCache(sd);
364 return NULL;
365 }
366 return sd;
367 }
368
369 /* Free a BSDF from our cache (clear all if NULL) */
370 void
371 SDfreeCache(const SDData *sd)
372 {
373 struct SDCache_s *sdl, *sdLast = NULL;
374
375 if (sd == NULL) { /* free entire list */
376 while ((sdl = SDcacheList) != NULL) {
377 SDcacheList = sdl->next;
378 SDfreeBSDF(&sdl->bsdf);
379 free(sdl);
380 }
381 return;
382 }
383 for (sdl = SDcacheList; sdl != NULL; sdl = (sdLast=sdl)->next)
384 if (&sdl->bsdf == sd)
385 break;
386 if (sdl == NULL || (sdl->refcnt -= (sdl->refcnt > 0)))
387 return; /* missing or still in use */
388 /* keep unreferenced data? */
389 if (SDisLoaded(sd) && SDretainSet) {
390 if (SDretainSet == SDretainAll)
391 return; /* keep everything */
392 /* else free cumulative data */
393 SDfreeCumulativeCache(sd->rf);
394 SDfreeCumulativeCache(sd->rb);
395 SDfreeCumulativeCache(sd->tf);
396 return;
397 }
398 /* remove from list and free */
399 if (sdLast == NULL)
400 SDcacheList = sdl->next;
401 else
402 sdLast->next = sdl->next;
403 SDfreeBSDF(&sdl->bsdf);
404 free(sdl);
405 }
406
407 /* Sample an individual BSDF component */
408 SDError
409 SDsampComponent(SDValue *sv, FVECT ioVec, double randX, SDComponent *sdc)
410 {
411 float coef[SDmaxCh];
412 SDError ec;
413 FVECT inVec;
414 const SDCDst *cd;
415 double d;
416 int n;
417 /* check arguments */
418 if ((sv == NULL) | (ioVec == NULL) | (sdc == NULL))
419 return SDEargument;
420 /* get cumulative distribution */
421 VCOPY(inVec, ioVec);
422 cd = (*sdc->func->getCDist)(inVec, sdc);
423 if (cd == NULL)
424 return SDEmemory;
425 if (cd->cTotal <= 1e-7) { /* anything to sample? */
426 sv->spec = c_dfcolor;
427 sv->cieY = .0;
428 memset(ioVec, 0, 3*sizeof(double));
429 return SDEnone;
430 }
431 sv->cieY = cd->cTotal;
432 /* compute sample direction */
433 ec = (*sdc->func->sampCDist)(ioVec, randX, cd);
434 if (ec)
435 return ec;
436 /* get BSDF color */
437 n = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc);
438 if (n <= 0) {
439 strcpy(SDerrorDetail, "BSDF sample value error");
440 return SDEinternal;
441 }
442 sv->spec = sdc->cspec[0];
443 d = coef[0];
444 while (--n) {
445 c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]);
446 d += coef[n];
447 }
448 /* make sure everything is set */
449 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
450 return SDEnone;
451 }
452
453 #define MS_MAXDIM 15
454
455 /* Convert 1-dimensional random variable to N-dimensional */
456 void
457 SDmultiSamp(double t[], int n, double randX)
458 {
459 unsigned nBits;
460 double scale;
461 bitmask_t ndx, coord[MS_MAXDIM];
462
463 while (n > MS_MAXDIM) /* punt for higher dimensions */
464 t[--n] = rand()*(1./(RAND_MAX+.5));
465 nBits = (8*sizeof(bitmask_t) - 1) / n;
466 ndx = randX * (double)((bitmask_t)1 << (nBits*n));
467 /* get coordinate on Hilbert curve */
468 hilbert_i2c(n, nBits, ndx, coord);
469 /* convert back to [0,1) range */
470 scale = 1. / (double)((bitmask_t)1 << nBits);
471 while (n--)
472 t[n] = scale * ((double)coord[n] + rand()*(1./(RAND_MAX+.5)));
473 }
474
475 #undef MS_MAXDIM
476
477 /* Generate diffuse hemispherical sample */
478 static void
479 SDdiffuseSamp(FVECT outVec, int outFront, double randX)
480 {
481 /* convert to position on hemisphere */
482 SDmultiSamp(outVec, 2, randX);
483 SDsquare2disk(outVec, outVec[0], outVec[1]);
484 outVec[2] = 1. - outVec[0]*outVec[0] - outVec[1]*outVec[1];
485 if (outVec[2] > 0) /* a bit of paranoia */
486 outVec[2] = sqrt(outVec[2]);
487 if (!outFront) /* going out back? */
488 outVec[2] = -outVec[2];
489 }
490
491 /* Query projected solid angle coverage for non-diffuse BSDF direction */
492 SDError
493 SDsizeBSDF(double *projSA, const FVECT v1, const RREAL *v2,
494 int qflags, const SDData *sd)
495 {
496 SDSpectralDF *rdf, *tdf;
497 SDError ec;
498 int i;
499 /* check arguments */
500 if ((projSA == NULL) | (v1 == NULL) | (sd == NULL))
501 return SDEargument;
502 /* initialize extrema */
503 switch (qflags) {
504 case SDqueryMax:
505 projSA[0] = .0;
506 break;
507 case SDqueryMin+SDqueryMax:
508 projSA[1] = .0;
509 /* fall through */
510 case SDqueryMin:
511 projSA[0] = 10.;
512 break;
513 case 0:
514 return SDEargument;
515 }
516 if (v1[2] > 0) /* front surface query? */
517 rdf = sd->rf;
518 else
519 rdf = sd->rb;
520 tdf = sd->tf;
521 if (v2 != NULL) /* bidirectional? */
522 if (v1[2] > 0 ^ v2[2] > 0)
523 rdf = NULL;
524 else
525 tdf = NULL;
526 ec = SDEdata; /* run through components */
527 for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) {
528 ec = (*rdf->comp[i].func->queryProjSA)(projSA, v1, v2,
529 qflags, &rdf->comp[i]);
530 if (ec)
531 return ec;
532 }
533 for (i = (tdf==NULL) ? 0 : tdf->ncomp; i--; ) {
534 ec = (*tdf->comp[i].func->queryProjSA)(projSA, v1, v2,
535 qflags, &tdf->comp[i]);
536 if (ec)
537 return ec;
538 }
539 if (ec) { /* all diffuse? */
540 projSA[0] = M_PI;
541 if (qflags == SDqueryMin+SDqueryMax)
542 projSA[1] = M_PI;
543 }
544 return SDEnone;
545 }
546
547 /* Return BSDF for the given incident and scattered ray vectors */
548 SDError
549 SDevalBSDF(SDValue *sv, const FVECT outVec, const FVECT inVec, const SDData *sd)
550 {
551 int inFront, outFront;
552 SDSpectralDF *sdf;
553 float coef[SDmaxCh];
554 int nch, i;
555 /* check arguments */
556 if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL))
557 return SDEargument;
558 /* whose side are we on? */
559 inFront = (inVec[2] > 0);
560 outFront = (outVec[2] > 0);
561 /* start with diffuse portion */
562 if (inFront & outFront) {
563 *sv = sd->rLambFront;
564 sdf = sd->rf;
565 } else if (!(inFront | outFront)) {
566 *sv = sd->rLambBack;
567 sdf = sd->rb;
568 } else /* inFront ^ outFront */ {
569 *sv = sd->tLamb;
570 sdf = sd->tf;
571 }
572 sv->cieY *= 1./M_PI;
573 /* add non-diffuse components */
574 i = (sdf != NULL) ? sdf->ncomp : 0;
575 while (i-- > 0) {
576 nch = (*sdf->comp[i].func->getBSDFs)(coef, outVec, inVec,
577 &sdf->comp[i]);
578 while (nch-- > 0) {
579 c_cmix(&sv->spec, sv->cieY, &sv->spec,
580 coef[nch], &sdf->comp[i].cspec[nch]);
581 sv->cieY += coef[nch];
582 }
583 }
584 /* make sure everything is set */
585 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
586 return SDEnone;
587 }
588
589 /* Compute directional hemispherical scattering at this incident angle */
590 double
591 SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd)
592 {
593 double hsum;
594 SDSpectralDF *rdf;
595 const SDCDst *cd;
596 int i;
597 /* check arguments */
598 if ((inVec == NULL) | (sd == NULL))
599 return .0;
600 /* gather diffuse components */
601 if (inVec[2] > 0) {
602 hsum = sd->rLambFront.cieY;
603 rdf = sd->rf;
604 } else /* !inFront */ {
605 hsum = sd->rLambBack.cieY;
606 rdf = sd->rb;
607 }
608 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
609 hsum = .0;
610 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
611 hsum += sd->tLamb.cieY;
612 /* gather non-diffuse components */
613 i = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
614 rdf != NULL) ? rdf->ncomp : 0;
615 while (i-- > 0) { /* non-diffuse reflection */
616 cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
617 if (cd != NULL)
618 hsum += cd->cTotal;
619 }
620 i = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
621 sd->tf != NULL) ? sd->tf->ncomp : 0;
622 while (i-- > 0) { /* non-diffuse transmission */
623 cd = (*sd->tf->comp[i].func->getCDist)(inVec, &sd->tf->comp[i]);
624 if (cd != NULL)
625 hsum += cd->cTotal;
626 }
627 return hsum;
628 }
629
630 /* Sample BSDF direction based on the given random variable */
631 SDError
632 SDsampBSDF(SDValue *sv, FVECT ioVec, double randX, int sflags, const SDData *sd)
633 {
634 SDError ec;
635 FVECT inVec;
636 int inFront;
637 SDSpectralDF *rdf;
638 double rdiff;
639 float coef[SDmaxCh];
640 int i, j, n, nr;
641 SDComponent *sdc;
642 const SDCDst **cdarr = NULL;
643 /* check arguments */
644 if ((sv == NULL) | (ioVec == NULL) | (sd == NULL) |
645 (randX < 0) | (randX >= 1.))
646 return SDEargument;
647 /* whose side are we on? */
648 VCOPY(inVec, ioVec);
649 inFront = (inVec[2] > 0);
650 /* remember diffuse portions */
651 if (inFront) {
652 *sv = sd->rLambFront;
653 rdf = sd->rf;
654 } else /* !inFront */ {
655 *sv = sd->rLambBack;
656 rdf = sd->rb;
657 }
658 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
659 sv->cieY = .0;
660 rdiff = sv->cieY;
661 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
662 sv->cieY += sd->tLamb.cieY;
663 /* gather non-diffuse components */
664 i = nr = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
665 rdf != NULL) ? rdf->ncomp : 0;
666 j = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
667 sd->tf != NULL) ? sd->tf->ncomp : 0;
668 n = i + j;
669 if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL)
670 return SDEmemory;
671 while (j-- > 0) { /* non-diffuse transmission */
672 cdarr[i+j] = (*sd->tf->comp[j].func->getCDist)(inVec, &sd->tf->comp[j]);
673 if (cdarr[i+j] == NULL) {
674 free(cdarr);
675 return SDEmemory;
676 }
677 sv->cieY += cdarr[i+j]->cTotal;
678 }
679 while (i-- > 0) { /* non-diffuse reflection */
680 cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
681 if (cdarr[i] == NULL) {
682 free(cdarr);
683 return SDEmemory;
684 }
685 sv->cieY += cdarr[i]->cTotal;
686 }
687 if (sv->cieY <= 1e-7) { /* anything to sample? */
688 sv->cieY = .0;
689 memset(ioVec, 0, 3*sizeof(double));
690 return SDEnone;
691 }
692 /* scale random variable */
693 randX *= sv->cieY;
694 /* diffuse reflection? */
695 if (randX < rdiff) {
696 SDdiffuseSamp(ioVec, inFront, randX/rdiff);
697 goto done;
698 }
699 randX -= rdiff;
700 /* diffuse transmission? */
701 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) {
702 if (randX < sd->tLamb.cieY) {
703 sv->spec = sd->tLamb.spec;
704 SDdiffuseSamp(ioVec, !inFront, randX/sd->tLamb.cieY);
705 goto done;
706 }
707 randX -= sd->tLamb.cieY;
708 }
709 /* else one of cumulative dist. */
710 for (i = 0; i < n && randX < cdarr[i]->cTotal; i++)
711 randX -= cdarr[i]->cTotal;
712 if (i >= n)
713 return SDEinternal;
714 /* compute sample direction */
715 sdc = (i < nr) ? &rdf->comp[i] : &sd->tf->comp[i-nr];
716 ec = (*sdc->func->sampCDist)(ioVec, randX/cdarr[i]->cTotal, cdarr[i]);
717 if (ec)
718 return ec;
719 /* compute color */
720 j = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc);
721 if (j <= 0) {
722 sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error",
723 sd->name);
724 return SDEinternal;
725 }
726 sv->spec = sdc->cspec[0];
727 rdiff = coef[0];
728 while (--j) {
729 c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]);
730 rdiff += coef[j];
731 }
732 done:
733 if (cdarr != NULL)
734 free(cdarr);
735 /* make sure everything is set */
736 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
737 return SDEnone;
738 }
739
740 /* Compute World->BSDF transform from surface normal and up (Y) vector */
741 SDError
742 SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec)
743 {
744 if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL))
745 return SDEargument;
746 VCOPY(vMtx[2], sNrm);
747 if (normalize(vMtx[2]) == 0)
748 return SDEargument;
749 fcross(vMtx[0], uVec, vMtx[2]);
750 if (normalize(vMtx[0]) == 0)
751 return SDEargument;
752 fcross(vMtx[1], vMtx[2], vMtx[0]);
753 return SDEnone;
754 }
755
756 /* Compute inverse transform */
757 SDError
758 SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3])
759 {
760 RREAL mTmp[3][3];
761 double d;
762
763 if ((iMtx == NULL) | (vMtx == NULL))
764 return SDEargument;
765 /* compute determinant */
766 mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2];
767 mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1];
768 mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2];
769 d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2];
770 if (d == 0) {
771 strcpy(SDerrorDetail, "Zero determinant in matrix inversion");
772 return SDEargument;
773 }
774 d = 1./d; /* invert matrix */
775 mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d;
776 mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]);
777 mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]);
778 mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]);
779 mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]);
780 mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]);
781 mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]);
782 memcpy(iMtx, mTmp, sizeof(mTmp));
783 return SDEnone;
784 }
785
786 /* Transform and normalize direction (column) vector */
787 SDError
788 SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec)
789 {
790 FVECT vTmp;
791
792 if ((resVec == NULL) | (inpVec == NULL))
793 return SDEargument;
794 if (vMtx == NULL) { /* assume they just want to normalize */
795 if (resVec != inpVec)
796 VCOPY(resVec, inpVec);
797 return (normalize(resVec) > 0) ? SDEnone : SDEargument;
798 }
799 vTmp[0] = DOT(vMtx[0], inpVec);
800 vTmp[1] = DOT(vMtx[1], inpVec);
801 vTmp[2] = DOT(vMtx[2], inpVec);
802 if (normalize(vTmp) == 0)
803 return SDEargument;
804 VCOPY(resVec, vTmp);
805 return SDEnone;
806 }
807
808 /*################################################################*/
809 /*######### DEPRECATED ROUTINES AWAITING PERMANENT REMOVAL #######*/
810
811 /*
812 * Routines for handling BSDF data
813 */
814
815 #include "standard.h"
816 #include "paths.h"
817
818 #define MAXLATS 46 /* maximum number of latitudes */
819
820 /* BSDF angle specification */
821 typedef struct {
822 char name[64]; /* basis name */
823 int nangles; /* total number of directions */
824 struct {
825 float tmin; /* starting theta */
826 short nphis; /* number of phis (0 term) */
827 } lat[MAXLATS+1]; /* latitudes */
828 } ANGLE_BASIS;
829
830 #define MAXABASES 7 /* limit on defined bases */
831
832 static ANGLE_BASIS abase_list[MAXABASES] = {
833 {
834 "LBNL/Klems Full", 145,
835 { {-5., 1},
836 {5., 8},
837 {15., 16},
838 {25., 20},
839 {35., 24},
840 {45., 24},
841 {55., 24},
842 {65., 16},
843 {75., 12},
844 {90., 0} }
845 }, {
846 "LBNL/Klems Half", 73,
847 { {-6.5, 1},
848 {6.5, 8},
849 {19.5, 12},
850 {32.5, 16},
851 {46.5, 20},
852 {61.5, 12},
853 {76.5, 4},
854 {90., 0} }
855 }, {
856 "LBNL/Klems Quarter", 41,
857 { {-9., 1},
858 {9., 8},
859 {27., 12},
860 {46., 12},
861 {66., 8},
862 {90., 0} }
863 }
864 };
865
866 static int nabases = 3; /* current number of defined bases */
867
868 #define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6)
869
870 static int
871 fequal(double a, double b)
872 {
873 if (b != 0)
874 a = a/b - 1.;
875 return((a <= 1e-6) & (a >= -1e-6));
876 }
877
878 /* Returns the name of the given tag */
879 #ifdef ezxml_name
880 #undef ezxml_name
881 static char *
882 ezxml_name(ezxml_t xml)
883 {
884 if (xml == NULL)
885 return(NULL);
886 return(xml->name);
887 }
888 #endif
889
890 /* Returns the given tag's character content or empty string if none */
891 #ifdef ezxml_txt
892 #undef ezxml_txt
893 static char *
894 ezxml_txt(ezxml_t xml)
895 {
896 if (xml == NULL)
897 return("");
898 return(xml->txt);
899 }
900 #endif
901
902
903 static int
904 ab_getvec( /* get vector for this angle basis index */
905 FVECT v,
906 int ndx,
907 void *p
908 )
909 {
910 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
911 int li;
912 double pol, azi, d;
913
914 if ((ndx < 0) | (ndx >= ab->nangles))
915 return(0);
916 for (li = 0; ndx >= ab->lat[li].nphis; li++)
917 ndx -= ab->lat[li].nphis;
918 pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin);
919 azi = 2.*PI*ndx/ab->lat[li].nphis;
920 v[2] = d = cos(pol);
921 d = sqrt(1. - d*d); /* sin(pol) */
922 v[0] = cos(azi)*d;
923 v[1] = sin(azi)*d;
924 return(1);
925 }
926
927
928 static int
929 ab_getndx( /* get index corresponding to the given vector */
930 FVECT v,
931 void *p
932 )
933 {
934 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
935 int li, ndx;
936 double pol, azi;
937
938 if ((v[2] < -1.0) | (v[2] > 1.0))
939 return(-1);
940 pol = 180.0/PI*acos(v[2]);
941 azi = 180.0/PI*atan2(v[1], v[0]);
942 if (azi < 0.0) azi += 360.0;
943 for (li = 1; ab->lat[li].tmin <= pol; li++)
944 if (!ab->lat[li].nphis)
945 return(-1);
946 --li;
947 ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5);
948 if (ndx >= ab->lat[li].nphis) ndx = 0;
949 while (li--)
950 ndx += ab->lat[li].nphis;
951 return(ndx);
952 }
953
954
955 static double
956 ab_getohm( /* get solid angle for this angle basis index */
957 int ndx,
958 void *p
959 )
960 {
961 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
962 int li;
963 double theta, theta1;
964
965 if ((ndx < 0) | (ndx >= ab->nangles))
966 return(0);
967 for (li = 0; ndx >= ab->lat[li].nphis; li++)
968 ndx -= ab->lat[li].nphis;
969 theta1 = PI/180. * ab->lat[li+1].tmin;
970 if (ab->lat[li].nphis == 1) { /* special case */
971 if (ab->lat[li].tmin > FTINY)
972 error(USER, "unsupported BSDF coordinate system");
973 return(2.*PI*(1. - cos(theta1)));
974 }
975 theta = PI/180. * ab->lat[li].tmin;
976 return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis);
977 }
978
979
980 static int
981 ab_getvecR( /* get reverse vector for this angle basis index */
982 FVECT v,
983 int ndx,
984 void *p
985 )
986 {
987 if (!ab_getvec(v, ndx, p))
988 return(0);
989
990 v[0] = -v[0];
991 v[1] = -v[1];
992 v[2] = -v[2];
993
994 return(1);
995 }
996
997
998 static int
999 ab_getndxR( /* get index corresponding to the reverse vector */
1000 FVECT v,
1001 void *p
1002 )
1003 {
1004 FVECT v2;
1005
1006 v2[0] = -v[0];
1007 v2[1] = -v[1];
1008 v2[2] = -v[2];
1009
1010 return ab_getndx(v2, p);
1011 }
1012
1013
1014 static void
1015 load_angle_basis( /* load custom BSDF angle basis */
1016 ezxml_t wab
1017 )
1018 {
1019 char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName"));
1020 ezxml_t wbb;
1021 int i;
1022
1023 if (!abname || !*abname)
1024 return;
1025 for (i = nabases; i--; )
1026 if (!strcasecmp(abname, abase_list[i].name))
1027 return; /* assume it's the same */
1028 if (nabases >= MAXABASES)
1029 error(INTERNAL, "too many angle bases");
1030 strcpy(abase_list[nabases].name, abname);
1031 abase_list[nabases].nangles = 0;
1032 for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock");
1033 wbb != NULL; i++, wbb = wbb->next) {
1034 if (i >= MAXLATS)
1035 error(INTERNAL, "too many latitudes in custom basis");
1036 abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt(
1037 ezxml_child(ezxml_child(wbb,
1038 "ThetaBounds"), "UpperTheta")));
1039 if (!i)
1040 abase_list[nabases].lat[i].tmin =
1041 -abase_list[nabases].lat[i+1].tmin;
1042 else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb,
1043 "ThetaBounds"), "LowerTheta"))),
1044 abase_list[nabases].lat[i].tmin))
1045 error(WARNING, "theta values disagree in custom basis");
1046 abase_list[nabases].nangles +=
1047 abase_list[nabases].lat[i].nphis =
1048 atoi(ezxml_txt(ezxml_child(wbb, "nPhis")));
1049 }
1050 abase_list[nabases++].lat[i].nphis = 0;
1051 }
1052
1053
1054 static void
1055 load_geometry( /* load geometric dimensions and description (if any) */
1056 struct BSDF_data *dp,
1057 ezxml_t wdb
1058 )
1059 {
1060 ezxml_t geom;
1061 double cfact;
1062 const char *fmt, *mgfstr;
1063
1064 dp->dim[0] = dp->dim[1] = dp->dim[2] = 0;
1065 dp->mgf = NULL;
1066 if ((geom = ezxml_child(wdb, "Width")) != NULL)
1067 dp->dim[0] = atof(ezxml_txt(geom)) *
1068 to_meters(ezxml_attr(geom, "unit"));
1069 if ((geom = ezxml_child(wdb, "Height")) != NULL)
1070 dp->dim[1] = atof(ezxml_txt(geom)) *
1071 to_meters(ezxml_attr(geom, "unit"));
1072 if ((geom = ezxml_child(wdb, "Thickness")) != NULL)
1073 dp->dim[2] = atof(ezxml_txt(geom)) *
1074 to_meters(ezxml_attr(geom, "unit"));
1075 if ((geom = ezxml_child(wdb, "Geometry")) == NULL ||
1076 (mgfstr = ezxml_txt(geom)) == NULL)
1077 return;
1078 if ((fmt = ezxml_attr(geom, "format")) != NULL &&
1079 strcasecmp(fmt, "MGF")) {
1080 sprintf(errmsg, "unrecognized geometry format '%s'", fmt);
1081 error(WARNING, errmsg);
1082 return;
1083 }
1084 cfact = to_meters(ezxml_attr(geom, "unit"));
1085 dp->mgf = (char *)malloc(strlen(mgfstr)+32);
1086 if (dp->mgf == NULL)
1087 error(SYSTEM, "out of memory in load_geometry");
1088 if (cfact < 0.99 || cfact > 1.01)
1089 sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr);
1090 else
1091 strcpy(dp->mgf, mgfstr);
1092 }
1093
1094
1095 static void
1096 load_bsdf_data( /* load BSDF distribution for this wavelength */
1097 struct BSDF_data *dp,
1098 ezxml_t wdb
1099 )
1100 {
1101 char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis"));
1102 char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis"));
1103 char *sdata;
1104 int i;
1105
1106 if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) {
1107 error(WARNING, "missing column/row basis for BSDF");
1108 return;
1109 }
1110 for (i = nabases; i--; )
1111 if (!strcasecmp(cbasis, abase_list[i].name)) {
1112 dp->ninc = abase_list[i].nangles;
1113 dp->ib_priv = (void *)&abase_list[i];
1114 dp->ib_vec = ab_getvecR;
1115 dp->ib_ndx = ab_getndxR;
1116 dp->ib_ohm = ab_getohm;
1117 break;
1118 }
1119 if (i < 0) {
1120 sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis);
1121 error(WARNING, errmsg);
1122 return;
1123 }
1124 for (i = nabases; i--; )
1125 if (!strcasecmp(rbasis, abase_list[i].name)) {
1126 dp->nout = abase_list[i].nangles;
1127 dp->ob_priv = (void *)&abase_list[i];
1128 dp->ob_vec = ab_getvec;
1129 dp->ob_ndx = ab_getndx;
1130 dp->ob_ohm = ab_getohm;
1131 break;
1132 }
1133 if (i < 0) {
1134 sprintf(errmsg, "undefined RowAngleBasis '%s'", rbasis);
1135 error(WARNING, errmsg);
1136 return;
1137 }
1138 /* read BSDF data */
1139 sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData"));
1140 if (!sdata || !*sdata) {
1141 error(WARNING, "missing BSDF ScatteringData");
1142 return;
1143 }
1144 dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout);
1145 if (dp->bsdf == NULL)
1146 error(SYSTEM, "out of memory in load_bsdf_data");
1147 for (i = 0; i < dp->ninc*dp->nout; i++) {
1148 char *sdnext = fskip(sdata);
1149 if (sdnext == NULL) {
1150 error(WARNING, "bad/missing BSDF ScatteringData");
1151 free(dp->bsdf); dp->bsdf = NULL;
1152 return;
1153 }
1154 while (*sdnext && isspace(*sdnext))
1155 sdnext++;
1156 if (*sdnext == ',') sdnext++;
1157 dp->bsdf[i] = atof(sdata);
1158 sdata = sdnext;
1159 }
1160 while (isspace(*sdata))
1161 sdata++;
1162 if (*sdata) {
1163 sprintf(errmsg, "%d extra characters after BSDF ScatteringData",
1164 (int)strlen(sdata));
1165 error(WARNING, errmsg);
1166 }
1167 }
1168
1169
1170 static int
1171 check_bsdf_data( /* check that BSDF data is sane */
1172 struct BSDF_data *dp
1173 )
1174 {
1175 double *omega_iarr, *omega_oarr;
1176 double dom, hemi_total, full_total;
1177 int nneg;
1178 FVECT v;
1179 int i, o;
1180
1181 if (dp == NULL || dp->bsdf == NULL)
1182 return(0);
1183 omega_iarr = (double *)calloc(dp->ninc, sizeof(double));
1184 omega_oarr = (double *)calloc(dp->nout, sizeof(double));
1185 if ((omega_iarr == NULL) | (omega_oarr == NULL))
1186 error(SYSTEM, "out of memory in check_bsdf_data");
1187 /* incoming projected solid angles */
1188 hemi_total = .0;
1189 for (i = dp->ninc; i--; ) {
1190 dom = getBSDF_incohm(dp,i);
1191 if (dom <= 0) {
1192 error(WARNING, "zero/negative incoming solid angle");
1193 continue;
1194 }
1195 if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) {
1196 error(WARNING, "illegal incoming BSDF direction");
1197 free(omega_iarr); free(omega_oarr);
1198 return(0);
1199 }
1200 hemi_total += omega_iarr[i] = dom * -v[2];
1201 }
1202 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1203 sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%",
1204 100.*(hemi_total/PI - 1.));
1205 error(WARNING, errmsg);
1206 }
1207 dom = PI / hemi_total; /* fix normalization */
1208 for (i = dp->ninc; i--; )
1209 omega_iarr[i] *= dom;
1210 /* outgoing projected solid angles */
1211 hemi_total = .0;
1212 for (o = dp->nout; o--; ) {
1213 dom = getBSDF_outohm(dp,o);
1214 if (dom <= 0) {
1215 error(WARNING, "zero/negative outgoing solid angle");
1216 continue;
1217 }
1218 if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) {
1219 error(WARNING, "illegal outgoing BSDF direction");
1220 free(omega_iarr); free(omega_oarr);
1221 return(0);
1222 }
1223 hemi_total += omega_oarr[o] = dom * v[2];
1224 }
1225 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1226 sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%",
1227 100.*(hemi_total/PI - 1.));
1228 error(WARNING, errmsg);
1229 }
1230 dom = PI / hemi_total; /* fix normalization */
1231 for (o = dp->nout; o--; )
1232 omega_oarr[o] *= dom;
1233 nneg = 0; /* check outgoing totals */
1234 for (i = 0; i < dp->ninc; i++) {
1235 hemi_total = .0;
1236 for (o = dp->nout; o--; ) {
1237 double f = BSDF_value(dp,i,o);
1238 if (f >= 0)
1239 hemi_total += f*omega_oarr[o];
1240 else {
1241 nneg += (f < -FTINY);
1242 BSDF_value(dp,i,o) = .0f;
1243 }
1244 }
1245 if (hemi_total > 1.01) {
1246 sprintf(errmsg,
1247 "incoming BSDF direction %d passes %.1f%% of light",
1248 i, 100.*hemi_total);
1249 error(WARNING, errmsg);
1250 }
1251 }
1252 if (nneg) {
1253 sprintf(errmsg, "%d negative BSDF values (ignored)", nneg);
1254 error(WARNING, errmsg);
1255 }
1256 full_total = .0; /* reverse roles and check again */
1257 for (o = 0; o < dp->nout; o++) {
1258 hemi_total = .0;
1259 for (i = dp->ninc; i--; )
1260 hemi_total += BSDF_value(dp,i,o) * omega_iarr[i];
1261
1262 if (hemi_total > 1.01) {
1263 sprintf(errmsg,
1264 "outgoing BSDF direction %d collects %.1f%% of light",
1265 o, 100.*hemi_total);
1266 error(WARNING, errmsg);
1267 }
1268 full_total += hemi_total*omega_oarr[o];
1269 }
1270 full_total /= PI;
1271 if (full_total > 1.00001) {
1272 sprintf(errmsg, "BSDF transfers %.4f%% of light",
1273 100.*full_total);
1274 error(WARNING, errmsg);
1275 }
1276 free(omega_iarr); free(omega_oarr);
1277 return(1);
1278 }
1279
1280
1281 struct BSDF_data *
1282 load_BSDF( /* load BSDF data from file */
1283 char *fname
1284 )
1285 {
1286 char *path;
1287 ezxml_t fl, wtl, wld, wdb;
1288 struct BSDF_data *dp;
1289
1290 path = getpath(fname, getrlibpath(), R_OK);
1291 if (path == NULL) {
1292 sprintf(errmsg, "cannot find BSDF file \"%s\"", fname);
1293 error(WARNING, errmsg);
1294 return(NULL);
1295 }
1296 fl = ezxml_parse_file(path);
1297 if (fl == NULL) {
1298 sprintf(errmsg, "cannot open BSDF \"%s\"", path);
1299 error(WARNING, errmsg);
1300 return(NULL);
1301 }
1302 if (ezxml_error(fl)[0]) {
1303 sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl));
1304 error(WARNING, errmsg);
1305 ezxml_free(fl);
1306 return(NULL);
1307 }
1308 if (strcmp(ezxml_name(fl), "WindowElement")) {
1309 sprintf(errmsg,
1310 "BSDF \"%s\": top level node not 'WindowElement'",
1311 path);
1312 error(WARNING, errmsg);
1313 ezxml_free(fl);
1314 return(NULL);
1315 }
1316 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
1317 if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl,
1318 "DataDefinition"), "IncidentDataStructure")),
1319 "Columns")) {
1320 sprintf(errmsg,
1321 "BSDF \"%s\": unsupported IncidentDataStructure",
1322 path);
1323 error(WARNING, errmsg);
1324 ezxml_free(fl);
1325 return(NULL);
1326 }
1327 load_angle_basis(ezxml_child(ezxml_child(wtl,
1328 "DataDefinition"), "AngleBasis"));
1329 dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data));
1330 load_geometry(dp, ezxml_child(wtl, "Material"));
1331 for (wld = ezxml_child(wtl, "WavelengthData");
1332 wld != NULL; wld = wld->next) {
1333 if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")),
1334 "Visible"))
1335 continue;
1336 for (wdb = ezxml_child(wld, "WavelengthDataBlock");
1337 wdb != NULL; wdb = wdb->next)
1338 if (!strcasecmp(ezxml_txt(ezxml_child(wdb,
1339 "WavelengthDataDirection")),
1340 "Transmission Front"))
1341 break;
1342 if (wdb != NULL) { /* load front BTDF */
1343 load_bsdf_data(dp, wdb);
1344 break; /* ignore the rest */
1345 }
1346 }
1347 ezxml_free(fl); /* done with XML file */
1348 if (!check_bsdf_data(dp)) {
1349 sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path);
1350 error(WARNING, errmsg);
1351 free_BSDF(dp);
1352 dp = NULL;
1353 }
1354 return(dp);
1355 }
1356
1357
1358 void
1359 free_BSDF( /* free BSDF data structure */
1360 struct BSDF_data *b
1361 )
1362 {
1363 if (b == NULL)
1364 return;
1365 if (b->mgf != NULL)
1366 free(b->mgf);
1367 if (b->bsdf != NULL)
1368 free(b->bsdf);
1369 free(b);
1370 }
1371
1372
1373 int
1374 r_BSDF_incvec( /* compute random input vector at given location */
1375 FVECT v,
1376 struct BSDF_data *b,
1377 int i,
1378 double rv,
1379 MAT4 xm
1380 )
1381 {
1382 FVECT pert;
1383 double rad;
1384 int j;
1385
1386 if (!getBSDF_incvec(v, b, i))
1387 return(0);
1388 rad = sqrt(getBSDF_incohm(b, i) / PI);
1389 multisamp(pert, 3, rv);
1390 for (j = 0; j < 3; j++)
1391 v[j] += rad*(2.*pert[j] - 1.);
1392 if (xm != NULL)
1393 multv3(v, v, xm);
1394 return(normalize(v) != 0.0);
1395 }
1396
1397
1398 int
1399 r_BSDF_outvec( /* compute random output vector at given location */
1400 FVECT v,
1401 struct BSDF_data *b,
1402 int o,
1403 double rv,
1404 MAT4 xm
1405 )
1406 {
1407 FVECT pert;
1408 double rad;
1409 int j;
1410
1411 if (!getBSDF_outvec(v, b, o))
1412 return(0);
1413 rad = sqrt(getBSDF_outohm(b, o) / PI);
1414 multisamp(pert, 3, rv);
1415 for (j = 0; j < 3; j++)
1416 v[j] += rad*(2.*pert[j] - 1.);
1417 if (xm != NULL)
1418 multv3(v, v, xm);
1419 return(normalize(v) != 0.0);
1420 }
1421
1422
1423 static int
1424 addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
1425 char *xfarg[],
1426 FVECT xp,
1427 FVECT yp,
1428 FVECT zp
1429 )
1430 {
1431 static char bufs[3][16];
1432 int bn = 0;
1433 char **xfp = xfarg;
1434 double theta;
1435
1436 if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) {
1437 /* Special case for X' along Z-axis */
1438 theta = -atan2(yp[0], yp[1]);
1439 *xfp++ = "-ry";
1440 *xfp++ = xp[2] < 0.0 ? "90" : "-90";
1441 *xfp++ = "-rz";
1442 sprintf(bufs[bn], "%f", theta*(180./PI));
1443 *xfp++ = bufs[bn++];
1444 return(xfp - xfarg);
1445 }
1446 theta = atan2(yp[2], zp[2]);
1447 if (!FEQ(theta,0.0)) {
1448 *xfp++ = "-rx";
1449 sprintf(bufs[bn], "%f", theta*(180./PI));
1450 *xfp++ = bufs[bn++];
1451 }
1452 theta = asin(-xp[2]);
1453 if (!FEQ(theta,0.0)) {
1454 *xfp++ = "-ry";
1455 sprintf(bufs[bn], " %f", theta*(180./PI));
1456 *xfp++ = bufs[bn++];
1457 }
1458 theta = atan2(xp[1], xp[0]);
1459 if (!FEQ(theta,0.0)) {
1460 *xfp++ = "-rz";
1461 sprintf(bufs[bn], "%f", theta*(180./PI));
1462 *xfp++ = bufs[bn++];
1463 }
1464 *xfp = NULL;
1465 return(xfp - xfarg);
1466 }
1467
1468
1469 int
1470 getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */
1471 MAT4 xm,
1472 FVECT nrm,
1473 UpDir ud,
1474 char *xfbuf
1475 )
1476 {
1477 char *xfargs[7];
1478 XF myxf;
1479 FVECT updir, xdest, ydest;
1480 int i;
1481
1482 updir[0] = updir[1] = updir[2] = 0.;
1483 switch (ud) {
1484 case UDzneg:
1485 updir[2] = -1.;
1486 break;
1487 case UDyneg:
1488 updir[1] = -1.;
1489 break;
1490 case UDxneg:
1491 updir[0] = -1.;
1492 break;
1493 case UDxpos:
1494 updir[0] = 1.;
1495 break;
1496 case UDypos:
1497 updir[1] = 1.;
1498 break;
1499 case UDzpos:
1500 updir[2] = 1.;
1501 break;
1502 case UDunknown:
1503 return(0);
1504 }
1505 fcross(xdest, updir, nrm);
1506 if (normalize(xdest) == 0.0)
1507 return(0);
1508 fcross(ydest, nrm, xdest);
1509 xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs);
1510 copymat4(xm, myxf.xfm);
1511 if (xfbuf == NULL)
1512 return(1);
1513 /* return xf arguments as well */
1514 for (i = 0; xfargs[i] != NULL; i++) {
1515 *xfbuf++ = ' ';
1516 strcpy(xfbuf, xfargs[i]);
1517 while (*xfbuf) ++xfbuf;
1518 }
1519 return(1);
1520 }
1521
1522 /*######### END DEPRECATED ROUTINES #######*/
1523 /*################################################################*/