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root/radiance/ray/src/common/bsdf.c
Revision: 2.27
Committed: Wed Apr 27 23:05:51 2011 UTC (13 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.26: +3 -1 lines
Log Message:
First test of variable-res BSDFs

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: bsdf.c,v 2.26 2011/04/25 15:48:05 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 #if 0
172 /* check our result */
173 switch (lastErr) {
174 case SDEformat:
175 case SDEdata:
176 case SDEsupport: /* possibly we just tried the wrong format */
177 lastErr = SDloadMtx(sd, wtl);
178 break;
179 default: /* variable res. OK else serious error */
180 break;
181 }
182 #endif
183 /* done with XML file */
184 ezxml_free(fl);
185
186 if (lastErr) { /* was there a load error? */
187 SDfreeBSDF(sd);
188 return lastErr;
189 }
190 /* remove any insignificant components */
191 if (sd->rf != NULL && sd->rf->maxHemi <= .001) {
192 SDfreeSpectralDF(sd->rf); sd->rf = NULL;
193 }
194 if (sd->rb != NULL && sd->rb->maxHemi <= .001) {
195 SDfreeSpectralDF(sd->rb); sd->rb = NULL;
196 }
197 if (sd->tf != NULL && sd->tf->maxHemi <= .001) {
198 SDfreeSpectralDF(sd->tf); sd->tf = NULL;
199 }
200 /* return success */
201 return SDEnone;
202 }
203
204 /* Allocate new spectral distribution function */
205 SDSpectralDF *
206 SDnewSpectralDF(int nc)
207 {
208 SDSpectralDF *df;
209
210 if (nc <= 0) {
211 strcpy(SDerrorDetail, "Zero component spectral DF request");
212 return NULL;
213 }
214 df = (SDSpectralDF *)malloc(sizeof(SDSpectralDF) +
215 (nc-1)*sizeof(SDComponent));
216 if (df == NULL) {
217 sprintf(SDerrorDetail,
218 "Cannot allocate %d component spectral DF", nc);
219 return NULL;
220 }
221 df->minProjSA = .0;
222 df->maxHemi = .0;
223 df->ncomp = nc;
224 memset(df->comp, 0, nc*sizeof(SDComponent));
225 return df;
226 }
227
228 /* Free cached cumulative distributions for BSDF component */
229 void
230 SDfreeCumulativeCache(SDSpectralDF *df)
231 {
232 int n;
233 SDCDst *cdp;
234
235 if (df == NULL)
236 return;
237 for (n = df->ncomp; n-- > 0; )
238 while ((cdp = df->comp[n].cdList) != NULL) {
239 df->comp[n].cdList = cdp->next;
240 free(cdp);
241 }
242 }
243
244 /* Free a spectral distribution function */
245 void
246 SDfreeSpectralDF(SDSpectralDF *df)
247 {
248 int n;
249
250 if (df == NULL)
251 return;
252 SDfreeCumulativeCache(df);
253 for (n = df->ncomp; n-- > 0; )
254 (*df->comp[n].func->freeSC)(df->comp[n].dist);
255 free(df);
256 }
257
258 /* Shorten file path to useable BSDF name, removing suffix */
259 void
260 SDclipName(char *res, const char *fname)
261 {
262 const char *cp, *dot = NULL;
263
264 for (cp = fname; *cp; cp++)
265 if (*cp == '.')
266 dot = cp;
267 if ((dot == NULL) | (dot < fname+2))
268 dot = cp;
269 if (dot - fname >= SDnameLn)
270 fname = dot - SDnameLn + 1;
271 while (fname < dot)
272 *res++ = *fname++;
273 *res = '\0';
274 }
275
276 /* Initialize an unused BSDF struct (simply clears to zeroes) */
277 void
278 SDclearBSDF(SDData *sd, const char *fname)
279 {
280 if (sd == NULL)
281 return;
282 memset(sd, 0, sizeof(SDData));
283 if (fname == NULL)
284 return;
285 SDclipName(sd->name, fname);
286 }
287
288 /* Free data associated with BSDF struct */
289 void
290 SDfreeBSDF(SDData *sd)
291 {
292 if (sd == NULL)
293 return;
294 if (sd->mgf != NULL) {
295 free(sd->mgf);
296 sd->mgf = NULL;
297 }
298 if (sd->rf != NULL) {
299 SDfreeSpectralDF(sd->rf);
300 sd->rf = NULL;
301 }
302 if (sd->rb != NULL) {
303 SDfreeSpectralDF(sd->rb);
304 sd->rb = NULL;
305 }
306 if (sd->tf != NULL) {
307 SDfreeSpectralDF(sd->tf);
308 sd->tf = NULL;
309 }
310 sd->rLambFront.cieY = .0;
311 sd->rLambFront.spec.flags = 0;
312 sd->rLambBack.cieY = .0;
313 sd->rLambBack.spec.flags = 0;
314 sd->tLamb.cieY = .0;
315 sd->tLamb.spec.flags = 0;
316 }
317
318 /* Find writeable BSDF by name, or allocate new cache entry if absent */
319 SDData *
320 SDgetCache(const char *bname)
321 {
322 struct SDCache_s *sdl;
323 char sdnam[SDnameLn];
324
325 if (bname == NULL)
326 return NULL;
327
328 SDclipName(sdnam, bname);
329 for (sdl = SDcacheList; sdl != NULL; sdl = sdl->next)
330 if (!strcmp(sdl->bsdf.name, sdnam)) {
331 sdl->refcnt++;
332 return &sdl->bsdf;
333 }
334
335 sdl = (struct SDCache_s *)calloc(1, sizeof(struct SDCache_s));
336 if (sdl == NULL)
337 return NULL;
338
339 strcpy(sdl->bsdf.name, sdnam);
340 sdl->next = SDcacheList;
341 SDcacheList = sdl;
342
343 sdl->refcnt = 1;
344 return &sdl->bsdf;
345 }
346
347 /* Get loaded BSDF from cache (or load and cache it on first call) */
348 /* Report any problem to stderr and return NULL on failure */
349 const SDData *
350 SDcacheFile(const char *fname)
351 {
352 SDData *sd;
353 SDError ec;
354
355 if (fname == NULL || !*fname)
356 return NULL;
357 SDerrorDetail[0] = '\0';
358 if ((sd = SDgetCache(fname)) == NULL) {
359 SDreportEnglish(SDEmemory, stderr);
360 return NULL;
361 }
362 if (!SDisLoaded(sd) && (ec = SDloadFile(sd, fname))) {
363 SDreportEnglish(ec, stderr);
364 SDfreeCache(sd);
365 return NULL;
366 }
367 return sd;
368 }
369
370 /* Free a BSDF from our cache (clear all if NULL) */
371 void
372 SDfreeCache(const SDData *sd)
373 {
374 struct SDCache_s *sdl, *sdLast = NULL;
375
376 if (sd == NULL) { /* free entire list */
377 while ((sdl = SDcacheList) != NULL) {
378 SDcacheList = sdl->next;
379 SDfreeBSDF(&sdl->bsdf);
380 free(sdl);
381 }
382 return;
383 }
384 for (sdl = SDcacheList; sdl != NULL; sdl = (sdLast=sdl)->next)
385 if (&sdl->bsdf == sd)
386 break;
387 if (sdl == NULL || (sdl->refcnt -= (sdl->refcnt > 0)))
388 return; /* missing or still in use */
389 /* keep unreferenced data? */
390 if (SDisLoaded(sd) && SDretainSet) {
391 if (SDretainSet == SDretainAll)
392 return; /* keep everything */
393 /* else free cumulative data */
394 SDfreeCumulativeCache(sd->rf);
395 SDfreeCumulativeCache(sd->rb);
396 SDfreeCumulativeCache(sd->tf);
397 return;
398 }
399 /* remove from list and free */
400 if (sdLast == NULL)
401 SDcacheList = sdl->next;
402 else
403 sdLast->next = sdl->next;
404 SDfreeBSDF(&sdl->bsdf);
405 free(sdl);
406 }
407
408 /* Sample an individual BSDF component */
409 SDError
410 SDsampComponent(SDValue *sv, FVECT ioVec, double randX, SDComponent *sdc)
411 {
412 float coef[SDmaxCh];
413 SDError ec;
414 FVECT inVec;
415 const SDCDst *cd;
416 double d;
417 int n;
418 /* check arguments */
419 if ((sv == NULL) | (ioVec == NULL) | (sdc == NULL))
420 return SDEargument;
421 /* get cumulative distribution */
422 VCOPY(inVec, ioVec);
423 cd = (*sdc->func->getCDist)(inVec, sdc);
424 if (cd == NULL)
425 return SDEmemory;
426 if (cd->cTotal <= 1e-7) { /* anything to sample? */
427 sv->spec = c_dfcolor;
428 sv->cieY = .0;
429 memset(ioVec, 0, 3*sizeof(double));
430 return SDEnone;
431 }
432 sv->cieY = cd->cTotal;
433 /* compute sample direction */
434 ec = (*sdc->func->sampCDist)(ioVec, randX, cd);
435 if (ec)
436 return ec;
437 /* get BSDF color */
438 n = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc);
439 if (n <= 0) {
440 strcpy(SDerrorDetail, "BSDF sample value error");
441 return SDEinternal;
442 }
443 sv->spec = sdc->cspec[0];
444 d = coef[0];
445 while (--n) {
446 c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]);
447 d += coef[n];
448 }
449 /* make sure everything is set */
450 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
451 return SDEnone;
452 }
453
454 #define MS_MAXDIM 15
455
456 /* Convert 1-dimensional random variable to N-dimensional */
457 void
458 SDmultiSamp(double t[], int n, double randX)
459 {
460 unsigned nBits;
461 double scale;
462 bitmask_t ndx, coord[MS_MAXDIM];
463
464 while (n > MS_MAXDIM) /* punt for higher dimensions */
465 t[--n] = rand()*(1./(RAND_MAX+.5));
466 nBits = (8*sizeof(bitmask_t) - 1) / n;
467 ndx = randX * (double)((bitmask_t)1 << (nBits*n));
468 /* get coordinate on Hilbert curve */
469 hilbert_i2c(n, nBits, ndx, coord);
470 /* convert back to [0,1) range */
471 scale = 1. / (double)((bitmask_t)1 << nBits);
472 while (n--)
473 t[n] = scale * ((double)coord[n] + rand()*(1./(RAND_MAX+.5)));
474 }
475
476 #undef MS_MAXDIM
477
478 /* Generate diffuse hemispherical sample */
479 static void
480 SDdiffuseSamp(FVECT outVec, int outFront, double randX)
481 {
482 /* convert to position on hemisphere */
483 SDmultiSamp(outVec, 2, randX);
484 SDsquare2disk(outVec, outVec[0], outVec[1]);
485 outVec[2] = 1. - outVec[0]*outVec[0] - outVec[1]*outVec[1];
486 if (outVec[2] > 0) /* a bit of paranoia */
487 outVec[2] = sqrt(outVec[2]);
488 if (!outFront) /* going out back? */
489 outVec[2] = -outVec[2];
490 }
491
492 /* Query projected solid angle coverage for non-diffuse BSDF direction */
493 SDError
494 SDsizeBSDF(double *projSA, const FVECT v1, const RREAL *v2,
495 int qflags, const SDData *sd)
496 {
497 SDSpectralDF *rdf, *tdf;
498 SDError ec;
499 int i;
500 /* check arguments */
501 if ((projSA == NULL) | (v1 == NULL) | (sd == NULL))
502 return SDEargument;
503 /* initialize extrema */
504 switch (qflags) {
505 case SDqueryMax:
506 projSA[0] = .0;
507 break;
508 case SDqueryMin+SDqueryMax:
509 projSA[1] = .0;
510 /* fall through */
511 case SDqueryMin:
512 projSA[0] = 10.;
513 break;
514 case 0:
515 return SDEargument;
516 }
517 if (v1[2] > 0) /* front surface query? */
518 rdf = sd->rf;
519 else
520 rdf = sd->rb;
521 tdf = sd->tf;
522 if (v2 != NULL) /* bidirectional? */
523 if (v1[2] > 0 ^ v2[2] > 0)
524 rdf = NULL;
525 else
526 tdf = NULL;
527 ec = SDEdata; /* run through components */
528 for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) {
529 ec = (*rdf->comp[i].func->queryProjSA)(projSA, v1, v2,
530 qflags, &rdf->comp[i]);
531 if (ec)
532 return ec;
533 }
534 for (i = (tdf==NULL) ? 0 : tdf->ncomp; i--; ) {
535 ec = (*tdf->comp[i].func->queryProjSA)(projSA, v1, v2,
536 qflags, &tdf->comp[i]);
537 if (ec)
538 return ec;
539 }
540 if (ec) { /* all diffuse? */
541 projSA[0] = M_PI;
542 if (qflags == SDqueryMin+SDqueryMax)
543 projSA[1] = M_PI;
544 }
545 return SDEnone;
546 }
547
548 /* Return BSDF for the given incident and scattered ray vectors */
549 SDError
550 SDevalBSDF(SDValue *sv, const FVECT outVec, const FVECT inVec, const SDData *sd)
551 {
552 int inFront, outFront;
553 SDSpectralDF *sdf;
554 float coef[SDmaxCh];
555 int nch, i;
556 /* check arguments */
557 if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL))
558 return SDEargument;
559 /* whose side are we on? */
560 inFront = (inVec[2] > 0);
561 outFront = (outVec[2] > 0);
562 /* start with diffuse portion */
563 if (inFront & outFront) {
564 *sv = sd->rLambFront;
565 sdf = sd->rf;
566 } else if (!(inFront | outFront)) {
567 *sv = sd->rLambBack;
568 sdf = sd->rb;
569 } else /* inFront ^ outFront */ {
570 *sv = sd->tLamb;
571 sdf = sd->tf;
572 }
573 sv->cieY *= 1./M_PI;
574 /* add non-diffuse components */
575 i = (sdf != NULL) ? sdf->ncomp : 0;
576 while (i-- > 0) {
577 nch = (*sdf->comp[i].func->getBSDFs)(coef, outVec, inVec,
578 &sdf->comp[i]);
579 while (nch-- > 0) {
580 c_cmix(&sv->spec, sv->cieY, &sv->spec,
581 coef[nch], &sdf->comp[i].cspec[nch]);
582 sv->cieY += coef[nch];
583 }
584 }
585 /* make sure everything is set */
586 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
587 return SDEnone;
588 }
589
590 /* Compute directional hemispherical scattering at this incident angle */
591 double
592 SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd)
593 {
594 double hsum;
595 SDSpectralDF *rdf;
596 const SDCDst *cd;
597 int i;
598 /* check arguments */
599 if ((inVec == NULL) | (sd == NULL))
600 return .0;
601 /* gather diffuse components */
602 if (inVec[2] > 0) {
603 hsum = sd->rLambFront.cieY;
604 rdf = sd->rf;
605 } else /* !inFront */ {
606 hsum = sd->rLambBack.cieY;
607 rdf = sd->rb;
608 }
609 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
610 hsum = .0;
611 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
612 hsum += sd->tLamb.cieY;
613 /* gather non-diffuse components */
614 i = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
615 rdf != NULL) ? rdf->ncomp : 0;
616 while (i-- > 0) { /* non-diffuse reflection */
617 cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
618 if (cd != NULL)
619 hsum += cd->cTotal;
620 }
621 i = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
622 sd->tf != NULL) ? sd->tf->ncomp : 0;
623 while (i-- > 0) { /* non-diffuse transmission */
624 cd = (*sd->tf->comp[i].func->getCDist)(inVec, &sd->tf->comp[i]);
625 if (cd != NULL)
626 hsum += cd->cTotal;
627 }
628 return hsum;
629 }
630
631 /* Sample BSDF direction based on the given random variable */
632 SDError
633 SDsampBSDF(SDValue *sv, FVECT ioVec, double randX, int sflags, const SDData *sd)
634 {
635 SDError ec;
636 FVECT inVec;
637 int inFront;
638 SDSpectralDF *rdf;
639 double rdiff;
640 float coef[SDmaxCh];
641 int i, j, n, nr;
642 SDComponent *sdc;
643 const SDCDst **cdarr = NULL;
644 /* check arguments */
645 if ((sv == NULL) | (ioVec == NULL) | (sd == NULL) |
646 (randX < 0) | (randX >= 1.))
647 return SDEargument;
648 /* whose side are we on? */
649 VCOPY(inVec, ioVec);
650 inFront = (inVec[2] > 0);
651 /* remember diffuse portions */
652 if (inFront) {
653 *sv = sd->rLambFront;
654 rdf = sd->rf;
655 } else /* !inFront */ {
656 *sv = sd->rLambBack;
657 rdf = sd->rb;
658 }
659 if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR)
660 sv->cieY = .0;
661 rdiff = sv->cieY;
662 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT)
663 sv->cieY += sd->tLamb.cieY;
664 /* gather non-diffuse components */
665 i = nr = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR &&
666 rdf != NULL) ? rdf->ncomp : 0;
667 j = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT &&
668 sd->tf != NULL) ? sd->tf->ncomp : 0;
669 n = i + j;
670 if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL)
671 return SDEmemory;
672 while (j-- > 0) { /* non-diffuse transmission */
673 cdarr[i+j] = (*sd->tf->comp[j].func->getCDist)(inVec, &sd->tf->comp[j]);
674 if (cdarr[i+j] == NULL) {
675 free(cdarr);
676 return SDEmemory;
677 }
678 sv->cieY += cdarr[i+j]->cTotal;
679 }
680 while (i-- > 0) { /* non-diffuse reflection */
681 cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]);
682 if (cdarr[i] == NULL) {
683 free(cdarr);
684 return SDEmemory;
685 }
686 sv->cieY += cdarr[i]->cTotal;
687 }
688 if (sv->cieY <= 1e-7) { /* anything to sample? */
689 sv->cieY = .0;
690 memset(ioVec, 0, 3*sizeof(double));
691 return SDEnone;
692 }
693 /* scale random variable */
694 randX *= sv->cieY;
695 /* diffuse reflection? */
696 if (randX < rdiff) {
697 SDdiffuseSamp(ioVec, inFront, randX/rdiff);
698 goto done;
699 }
700 randX -= rdiff;
701 /* diffuse transmission? */
702 if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) {
703 if (randX < sd->tLamb.cieY) {
704 sv->spec = sd->tLamb.spec;
705 SDdiffuseSamp(ioVec, !inFront, randX/sd->tLamb.cieY);
706 goto done;
707 }
708 randX -= sd->tLamb.cieY;
709 }
710 /* else one of cumulative dist. */
711 for (i = 0; i < n && randX < cdarr[i]->cTotal; i++)
712 randX -= cdarr[i]->cTotal;
713 if (i >= n)
714 return SDEinternal;
715 /* compute sample direction */
716 sdc = (i < nr) ? &rdf->comp[i] : &sd->tf->comp[i-nr];
717 ec = (*sdc->func->sampCDist)(ioVec, randX/cdarr[i]->cTotal, cdarr[i]);
718 if (ec)
719 return ec;
720 /* compute color */
721 j = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc);
722 if (j <= 0) {
723 sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error",
724 sd->name);
725 return SDEinternal;
726 }
727 sv->spec = sdc->cspec[0];
728 rdiff = coef[0];
729 while (--j) {
730 c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]);
731 rdiff += coef[j];
732 }
733 done:
734 if (cdarr != NULL)
735 free(cdarr);
736 /* make sure everything is set */
737 c_ccvt(&sv->spec, C_CSXY+C_CSSPEC);
738 return SDEnone;
739 }
740
741 /* Compute World->BSDF transform from surface normal and up (Y) vector */
742 SDError
743 SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec)
744 {
745 if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL))
746 return SDEargument;
747 VCOPY(vMtx[2], sNrm);
748 if (normalize(vMtx[2]) == 0)
749 return SDEargument;
750 fcross(vMtx[0], uVec, vMtx[2]);
751 if (normalize(vMtx[0]) == 0)
752 return SDEargument;
753 fcross(vMtx[1], vMtx[2], vMtx[0]);
754 return SDEnone;
755 }
756
757 /* Compute inverse transform */
758 SDError
759 SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3])
760 {
761 RREAL mTmp[3][3];
762 double d;
763
764 if ((iMtx == NULL) | (vMtx == NULL))
765 return SDEargument;
766 /* compute determinant */
767 mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2];
768 mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1];
769 mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2];
770 d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2];
771 if (d == 0) {
772 strcpy(SDerrorDetail, "Zero determinant in matrix inversion");
773 return SDEargument;
774 }
775 d = 1./d; /* invert matrix */
776 mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d;
777 mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]);
778 mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]);
779 mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]);
780 mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]);
781 mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]);
782 mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]);
783 memcpy(iMtx, mTmp, sizeof(mTmp));
784 return SDEnone;
785 }
786
787 /* Transform and normalize direction (column) vector */
788 SDError
789 SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec)
790 {
791 FVECT vTmp;
792
793 if ((resVec == NULL) | (inpVec == NULL))
794 return SDEargument;
795 if (vMtx == NULL) { /* assume they just want to normalize */
796 if (resVec != inpVec)
797 VCOPY(resVec, inpVec);
798 return (normalize(resVec) > 0) ? SDEnone : SDEargument;
799 }
800 vTmp[0] = DOT(vMtx[0], inpVec);
801 vTmp[1] = DOT(vMtx[1], inpVec);
802 vTmp[2] = DOT(vMtx[2], inpVec);
803 if (normalize(vTmp) == 0)
804 return SDEargument;
805 VCOPY(resVec, vTmp);
806 return SDEnone;
807 }
808
809 /*################################################################*/
810 /*######### DEPRECATED ROUTINES AWAITING PERMANENT REMOVAL #######*/
811
812 /*
813 * Routines for handling BSDF data
814 */
815
816 #include "standard.h"
817 #include "paths.h"
818 #include <ctype.h>
819
820 #define MAXLATS 46 /* maximum number of latitudes */
821
822 /* BSDF angle specification */
823 typedef struct {
824 char name[64]; /* basis name */
825 int nangles; /* total number of directions */
826 struct {
827 float tmin; /* starting theta */
828 short nphis; /* number of phis (0 term) */
829 } lat[MAXLATS+1]; /* latitudes */
830 } ANGLE_BASIS;
831
832 #define MAXABASES 7 /* limit on defined bases */
833
834 static ANGLE_BASIS abase_list[MAXABASES] = {
835 {
836 "LBNL/Klems Full", 145,
837 { {-5., 1},
838 {5., 8},
839 {15., 16},
840 {25., 20},
841 {35., 24},
842 {45., 24},
843 {55., 24},
844 {65., 16},
845 {75., 12},
846 {90., 0} }
847 }, {
848 "LBNL/Klems Half", 73,
849 { {-6.5, 1},
850 {6.5, 8},
851 {19.5, 12},
852 {32.5, 16},
853 {46.5, 20},
854 {61.5, 12},
855 {76.5, 4},
856 {90., 0} }
857 }, {
858 "LBNL/Klems Quarter", 41,
859 { {-9., 1},
860 {9., 8},
861 {27., 12},
862 {46., 12},
863 {66., 8},
864 {90., 0} }
865 }
866 };
867
868 static int nabases = 3; /* current number of defined bases */
869
870 #define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6)
871
872 static int
873 fequal(double a, double b)
874 {
875 if (b != 0)
876 a = a/b - 1.;
877 return((a <= 1e-6) & (a >= -1e-6));
878 }
879
880 /* Returns the name of the given tag */
881 #ifdef ezxml_name
882 #undef ezxml_name
883 static char *
884 ezxml_name(ezxml_t xml)
885 {
886 if (xml == NULL)
887 return(NULL);
888 return(xml->name);
889 }
890 #endif
891
892 /* Returns the given tag's character content or empty string if none */
893 #ifdef ezxml_txt
894 #undef ezxml_txt
895 static char *
896 ezxml_txt(ezxml_t xml)
897 {
898 if (xml == NULL)
899 return("");
900 return(xml->txt);
901 }
902 #endif
903
904
905 static int
906 ab_getvec( /* get vector for this angle basis index */
907 FVECT v,
908 int ndx,
909 void *p
910 )
911 {
912 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
913 int li;
914 double pol, azi, d;
915
916 if ((ndx < 0) | (ndx >= ab->nangles))
917 return(0);
918 for (li = 0; ndx >= ab->lat[li].nphis; li++)
919 ndx -= ab->lat[li].nphis;
920 pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin);
921 azi = 2.*PI*ndx/ab->lat[li].nphis;
922 v[2] = d = cos(pol);
923 d = sqrt(1. - d*d); /* sin(pol) */
924 v[0] = cos(azi)*d;
925 v[1] = sin(azi)*d;
926 return(1);
927 }
928
929
930 static int
931 ab_getndx( /* get index corresponding to the given vector */
932 FVECT v,
933 void *p
934 )
935 {
936 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
937 int li, ndx;
938 double pol, azi, d;
939
940 if ((v[2] < -1.0) | (v[2] > 1.0))
941 return(-1);
942 pol = 180.0/PI*acos(v[2]);
943 azi = 180.0/PI*atan2(v[1], v[0]);
944 if (azi < 0.0) azi += 360.0;
945 for (li = 1; ab->lat[li].tmin <= pol; li++)
946 if (!ab->lat[li].nphis)
947 return(-1);
948 --li;
949 ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5);
950 if (ndx >= ab->lat[li].nphis) ndx = 0;
951 while (li--)
952 ndx += ab->lat[li].nphis;
953 return(ndx);
954 }
955
956
957 static double
958 ab_getohm( /* get solid angle for this angle basis index */
959 int ndx,
960 void *p
961 )
962 {
963 ANGLE_BASIS *ab = (ANGLE_BASIS *)p;
964 int li;
965 double theta, theta1;
966
967 if ((ndx < 0) | (ndx >= ab->nangles))
968 return(0);
969 for (li = 0; ndx >= ab->lat[li].nphis; li++)
970 ndx -= ab->lat[li].nphis;
971 theta1 = PI/180. * ab->lat[li+1].tmin;
972 if (ab->lat[li].nphis == 1) { /* special case */
973 if (ab->lat[li].tmin > FTINY)
974 error(USER, "unsupported BSDF coordinate system");
975 return(2.*PI*(1. - cos(theta1)));
976 }
977 theta = PI/180. * ab->lat[li].tmin;
978 return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis);
979 }
980
981
982 static int
983 ab_getvecR( /* get reverse vector for this angle basis index */
984 FVECT v,
985 int ndx,
986 void *p
987 )
988 {
989 if (!ab_getvec(v, ndx, p))
990 return(0);
991
992 v[0] = -v[0];
993 v[1] = -v[1];
994 v[2] = -v[2];
995
996 return(1);
997 }
998
999
1000 static int
1001 ab_getndxR( /* get index corresponding to the reverse vector */
1002 FVECT v,
1003 void *p
1004 )
1005 {
1006 FVECT v2;
1007
1008 v2[0] = -v[0];
1009 v2[1] = -v[1];
1010 v2[2] = -v[2];
1011
1012 return ab_getndx(v2, p);
1013 }
1014
1015
1016 static void
1017 load_angle_basis( /* load custom BSDF angle basis */
1018 ezxml_t wab
1019 )
1020 {
1021 char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName"));
1022 ezxml_t wbb;
1023 int i;
1024
1025 if (!abname || !*abname)
1026 return;
1027 for (i = nabases; i--; )
1028 if (!strcasecmp(abname, abase_list[i].name))
1029 return; /* assume it's the same */
1030 if (nabases >= MAXABASES)
1031 error(INTERNAL, "too many angle bases");
1032 strcpy(abase_list[nabases].name, abname);
1033 abase_list[nabases].nangles = 0;
1034 for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock");
1035 wbb != NULL; i++, wbb = wbb->next) {
1036 if (i >= MAXLATS)
1037 error(INTERNAL, "too many latitudes in custom basis");
1038 abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt(
1039 ezxml_child(ezxml_child(wbb,
1040 "ThetaBounds"), "UpperTheta")));
1041 if (!i)
1042 abase_list[nabases].lat[i].tmin =
1043 -abase_list[nabases].lat[i+1].tmin;
1044 else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb,
1045 "ThetaBounds"), "LowerTheta"))),
1046 abase_list[nabases].lat[i].tmin))
1047 error(WARNING, "theta values disagree in custom basis");
1048 abase_list[nabases].nangles +=
1049 abase_list[nabases].lat[i].nphis =
1050 atoi(ezxml_txt(ezxml_child(wbb, "nPhis")));
1051 }
1052 abase_list[nabases++].lat[i].nphis = 0;
1053 }
1054
1055
1056 static void
1057 load_geometry( /* load geometric dimensions and description (if any) */
1058 struct BSDF_data *dp,
1059 ezxml_t wdb
1060 )
1061 {
1062 ezxml_t geom;
1063 double cfact;
1064 const char *fmt, *mgfstr;
1065
1066 dp->dim[0] = dp->dim[1] = dp->dim[2] = 0;
1067 dp->mgf = NULL;
1068 if ((geom = ezxml_child(wdb, "Width")) != NULL)
1069 dp->dim[0] = atof(ezxml_txt(geom)) *
1070 to_meters(ezxml_attr(geom, "unit"));
1071 if ((geom = ezxml_child(wdb, "Height")) != NULL)
1072 dp->dim[1] = atof(ezxml_txt(geom)) *
1073 to_meters(ezxml_attr(geom, "unit"));
1074 if ((geom = ezxml_child(wdb, "Thickness")) != NULL)
1075 dp->dim[2] = atof(ezxml_txt(geom)) *
1076 to_meters(ezxml_attr(geom, "unit"));
1077 if ((geom = ezxml_child(wdb, "Geometry")) == NULL ||
1078 (mgfstr = ezxml_txt(geom)) == NULL)
1079 return;
1080 if ((fmt = ezxml_attr(geom, "format")) != NULL &&
1081 strcasecmp(fmt, "MGF")) {
1082 sprintf(errmsg, "unrecognized geometry format '%s'", fmt);
1083 error(WARNING, errmsg);
1084 return;
1085 }
1086 cfact = to_meters(ezxml_attr(geom, "unit"));
1087 dp->mgf = (char *)malloc(strlen(mgfstr)+32);
1088 if (dp->mgf == NULL)
1089 error(SYSTEM, "out of memory in load_geometry");
1090 if (cfact < 0.99 || cfact > 1.01)
1091 sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr);
1092 else
1093 strcpy(dp->mgf, mgfstr);
1094 }
1095
1096
1097 static void
1098 load_bsdf_data( /* load BSDF distribution for this wavelength */
1099 struct BSDF_data *dp,
1100 ezxml_t wdb
1101 )
1102 {
1103 char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis"));
1104 char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis"));
1105 char *sdata;
1106 int i;
1107
1108 if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) {
1109 error(WARNING, "missing column/row basis for BSDF");
1110 return;
1111 }
1112 for (i = nabases; i--; )
1113 if (!strcasecmp(cbasis, abase_list[i].name)) {
1114 dp->ninc = abase_list[i].nangles;
1115 dp->ib_priv = (void *)&abase_list[i];
1116 dp->ib_vec = ab_getvecR;
1117 dp->ib_ndx = ab_getndxR;
1118 dp->ib_ohm = ab_getohm;
1119 break;
1120 }
1121 if (i < 0) {
1122 sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis);
1123 error(WARNING, errmsg);
1124 return;
1125 }
1126 for (i = nabases; i--; )
1127 if (!strcasecmp(rbasis, abase_list[i].name)) {
1128 dp->nout = abase_list[i].nangles;
1129 dp->ob_priv = (void *)&abase_list[i];
1130 dp->ob_vec = ab_getvec;
1131 dp->ob_ndx = ab_getndx;
1132 dp->ob_ohm = ab_getohm;
1133 break;
1134 }
1135 if (i < 0) {
1136 sprintf(errmsg, "undefined RowAngleBasis '%s'", rbasis);
1137 error(WARNING, errmsg);
1138 return;
1139 }
1140 /* read BSDF data */
1141 sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData"));
1142 if (!sdata || !*sdata) {
1143 error(WARNING, "missing BSDF ScatteringData");
1144 return;
1145 }
1146 dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout);
1147 if (dp->bsdf == NULL)
1148 error(SYSTEM, "out of memory in load_bsdf_data");
1149 for (i = 0; i < dp->ninc*dp->nout; i++) {
1150 char *sdnext = fskip(sdata);
1151 if (sdnext == NULL) {
1152 error(WARNING, "bad/missing BSDF ScatteringData");
1153 free(dp->bsdf); dp->bsdf = NULL;
1154 return;
1155 }
1156 while (*sdnext && isspace(*sdnext))
1157 sdnext++;
1158 if (*sdnext == ',') sdnext++;
1159 dp->bsdf[i] = atof(sdata);
1160 sdata = sdnext;
1161 }
1162 while (isspace(*sdata))
1163 sdata++;
1164 if (*sdata) {
1165 sprintf(errmsg, "%d extra characters after BSDF ScatteringData",
1166 (int)strlen(sdata));
1167 error(WARNING, errmsg);
1168 }
1169 }
1170
1171
1172 static int
1173 check_bsdf_data( /* check that BSDF data is sane */
1174 struct BSDF_data *dp
1175 )
1176 {
1177 double *omega_iarr, *omega_oarr;
1178 double dom, contrib, hemi_total, full_total;
1179 int nneg;
1180 FVECT v;
1181 int i, o;
1182
1183 if (dp == NULL || dp->bsdf == NULL)
1184 return(0);
1185 omega_iarr = (double *)calloc(dp->ninc, sizeof(double));
1186 omega_oarr = (double *)calloc(dp->nout, sizeof(double));
1187 if ((omega_iarr == NULL) | (omega_oarr == NULL))
1188 error(SYSTEM, "out of memory in check_bsdf_data");
1189 /* incoming projected solid angles */
1190 hemi_total = .0;
1191 for (i = dp->ninc; i--; ) {
1192 dom = getBSDF_incohm(dp,i);
1193 if (dom <= 0) {
1194 error(WARNING, "zero/negative incoming solid angle");
1195 continue;
1196 }
1197 if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) {
1198 error(WARNING, "illegal incoming BSDF direction");
1199 free(omega_iarr); free(omega_oarr);
1200 return(0);
1201 }
1202 hemi_total += omega_iarr[i] = dom * -v[2];
1203 }
1204 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1205 sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%",
1206 100.*(hemi_total/PI - 1.));
1207 error(WARNING, errmsg);
1208 }
1209 dom = PI / hemi_total; /* fix normalization */
1210 for (i = dp->ninc; i--; )
1211 omega_iarr[i] *= dom;
1212 /* outgoing projected solid angles */
1213 hemi_total = .0;
1214 for (o = dp->nout; o--; ) {
1215 dom = getBSDF_outohm(dp,o);
1216 if (dom <= 0) {
1217 error(WARNING, "zero/negative outgoing solid angle");
1218 continue;
1219 }
1220 if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) {
1221 error(WARNING, "illegal outgoing BSDF direction");
1222 free(omega_iarr); free(omega_oarr);
1223 return(0);
1224 }
1225 hemi_total += omega_oarr[o] = dom * v[2];
1226 }
1227 if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) {
1228 sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%",
1229 100.*(hemi_total/PI - 1.));
1230 error(WARNING, errmsg);
1231 }
1232 dom = PI / hemi_total; /* fix normalization */
1233 for (o = dp->nout; o--; )
1234 omega_oarr[o] *= dom;
1235 nneg = 0; /* check outgoing totals */
1236 for (i = 0; i < dp->ninc; i++) {
1237 hemi_total = .0;
1238 for (o = dp->nout; o--; ) {
1239 double f = BSDF_value(dp,i,o);
1240 if (f >= 0)
1241 hemi_total += f*omega_oarr[o];
1242 else {
1243 nneg += (f < -FTINY);
1244 BSDF_value(dp,i,o) = .0f;
1245 }
1246 }
1247 if (hemi_total > 1.01) {
1248 sprintf(errmsg,
1249 "incoming BSDF direction %d passes %.1f%% of light",
1250 i, 100.*hemi_total);
1251 error(WARNING, errmsg);
1252 }
1253 }
1254 if (nneg) {
1255 sprintf(errmsg, "%d negative BSDF values (ignored)", nneg);
1256 error(WARNING, errmsg);
1257 }
1258 full_total = .0; /* reverse roles and check again */
1259 for (o = 0; o < dp->nout; o++) {
1260 hemi_total = .0;
1261 for (i = dp->ninc; i--; )
1262 hemi_total += BSDF_value(dp,i,o) * omega_iarr[i];
1263
1264 if (hemi_total > 1.01) {
1265 sprintf(errmsg,
1266 "outgoing BSDF direction %d collects %.1f%% of light",
1267 o, 100.*hemi_total);
1268 error(WARNING, errmsg);
1269 }
1270 full_total += hemi_total*omega_oarr[o];
1271 }
1272 full_total /= PI;
1273 if (full_total > 1.00001) {
1274 sprintf(errmsg, "BSDF transfers %.4f%% of light",
1275 100.*full_total);
1276 error(WARNING, errmsg);
1277 }
1278 free(omega_iarr); free(omega_oarr);
1279 return(1);
1280 }
1281
1282
1283 struct BSDF_data *
1284 load_BSDF( /* load BSDF data from file */
1285 char *fname
1286 )
1287 {
1288 char *path;
1289 ezxml_t fl, wtl, wld, wdb;
1290 struct BSDF_data *dp;
1291
1292 path = getpath(fname, getrlibpath(), R_OK);
1293 if (path == NULL) {
1294 sprintf(errmsg, "cannot find BSDF file \"%s\"", fname);
1295 error(WARNING, errmsg);
1296 return(NULL);
1297 }
1298 fl = ezxml_parse_file(path);
1299 if (fl == NULL) {
1300 sprintf(errmsg, "cannot open BSDF \"%s\"", path);
1301 error(WARNING, errmsg);
1302 return(NULL);
1303 }
1304 if (ezxml_error(fl)[0]) {
1305 sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl));
1306 error(WARNING, errmsg);
1307 ezxml_free(fl);
1308 return(NULL);
1309 }
1310 if (strcmp(ezxml_name(fl), "WindowElement")) {
1311 sprintf(errmsg,
1312 "BSDF \"%s\": top level node not 'WindowElement'",
1313 path);
1314 error(WARNING, errmsg);
1315 ezxml_free(fl);
1316 return(NULL);
1317 }
1318 wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer");
1319 if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl,
1320 "DataDefinition"), "IncidentDataStructure")),
1321 "Columns")) {
1322 sprintf(errmsg,
1323 "BSDF \"%s\": unsupported IncidentDataStructure",
1324 path);
1325 error(WARNING, errmsg);
1326 ezxml_free(fl);
1327 return(NULL);
1328 }
1329 load_angle_basis(ezxml_child(ezxml_child(wtl,
1330 "DataDefinition"), "AngleBasis"));
1331 dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data));
1332 load_geometry(dp, ezxml_child(wtl, "Material"));
1333 for (wld = ezxml_child(wtl, "WavelengthData");
1334 wld != NULL; wld = wld->next) {
1335 if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")),
1336 "Visible"))
1337 continue;
1338 for (wdb = ezxml_child(wld, "WavelengthDataBlock");
1339 wdb != NULL; wdb = wdb->next)
1340 if (!strcasecmp(ezxml_txt(ezxml_child(wdb,
1341 "WavelengthDataDirection")),
1342 "Transmission Front"))
1343 break;
1344 if (wdb != NULL) { /* load front BTDF */
1345 load_bsdf_data(dp, wdb);
1346 break; /* ignore the rest */
1347 }
1348 }
1349 ezxml_free(fl); /* done with XML file */
1350 if (!check_bsdf_data(dp)) {
1351 sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path);
1352 error(WARNING, errmsg);
1353 free_BSDF(dp);
1354 dp = NULL;
1355 }
1356 return(dp);
1357 }
1358
1359
1360 void
1361 free_BSDF( /* free BSDF data structure */
1362 struct BSDF_data *b
1363 )
1364 {
1365 if (b == NULL)
1366 return;
1367 if (b->mgf != NULL)
1368 free(b->mgf);
1369 if (b->bsdf != NULL)
1370 free(b->bsdf);
1371 free(b);
1372 }
1373
1374
1375 int
1376 r_BSDF_incvec( /* compute random input vector at given location */
1377 FVECT v,
1378 struct BSDF_data *b,
1379 int i,
1380 double rv,
1381 MAT4 xm
1382 )
1383 {
1384 FVECT pert;
1385 double rad;
1386 int j;
1387
1388 if (!getBSDF_incvec(v, b, i))
1389 return(0);
1390 rad = sqrt(getBSDF_incohm(b, i) / PI);
1391 multisamp(pert, 3, rv);
1392 for (j = 0; j < 3; j++)
1393 v[j] += rad*(2.*pert[j] - 1.);
1394 if (xm != NULL)
1395 multv3(v, v, xm);
1396 return(normalize(v) != 0.0);
1397 }
1398
1399
1400 int
1401 r_BSDF_outvec( /* compute random output vector at given location */
1402 FVECT v,
1403 struct BSDF_data *b,
1404 int o,
1405 double rv,
1406 MAT4 xm
1407 )
1408 {
1409 FVECT pert;
1410 double rad;
1411 int j;
1412
1413 if (!getBSDF_outvec(v, b, o))
1414 return(0);
1415 rad = sqrt(getBSDF_outohm(b, o) / PI);
1416 multisamp(pert, 3, rv);
1417 for (j = 0; j < 3; j++)
1418 v[j] += rad*(2.*pert[j] - 1.);
1419 if (xm != NULL)
1420 multv3(v, v, xm);
1421 return(normalize(v) != 0.0);
1422 }
1423
1424
1425 static int
1426 addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */
1427 char *xfarg[],
1428 FVECT xp,
1429 FVECT yp,
1430 FVECT zp
1431 )
1432 {
1433 static char bufs[3][16];
1434 int bn = 0;
1435 char **xfp = xfarg;
1436 double theta;
1437
1438 if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) {
1439 /* Special case for X' along Z-axis */
1440 theta = -atan2(yp[0], yp[1]);
1441 *xfp++ = "-ry";
1442 *xfp++ = xp[2] < 0.0 ? "90" : "-90";
1443 *xfp++ = "-rz";
1444 sprintf(bufs[bn], "%f", theta*(180./PI));
1445 *xfp++ = bufs[bn++];
1446 return(xfp - xfarg);
1447 }
1448 theta = atan2(yp[2], zp[2]);
1449 if (!FEQ(theta,0.0)) {
1450 *xfp++ = "-rx";
1451 sprintf(bufs[bn], "%f", theta*(180./PI));
1452 *xfp++ = bufs[bn++];
1453 }
1454 theta = asin(-xp[2]);
1455 if (!FEQ(theta,0.0)) {
1456 *xfp++ = "-ry";
1457 sprintf(bufs[bn], " %f", theta*(180./PI));
1458 *xfp++ = bufs[bn++];
1459 }
1460 theta = atan2(xp[1], xp[0]);
1461 if (!FEQ(theta,0.0)) {
1462 *xfp++ = "-rz";
1463 sprintf(bufs[bn], "%f", theta*(180./PI));
1464 *xfp++ = bufs[bn++];
1465 }
1466 *xfp = NULL;
1467 return(xfp - xfarg);
1468 }
1469
1470
1471 int
1472 getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */
1473 MAT4 xm,
1474 FVECT nrm,
1475 UpDir ud,
1476 char *xfbuf
1477 )
1478 {
1479 char *xfargs[7];
1480 XF myxf;
1481 FVECT updir, xdest, ydest;
1482 int i;
1483
1484 updir[0] = updir[1] = updir[2] = 0.;
1485 switch (ud) {
1486 case UDzneg:
1487 updir[2] = -1.;
1488 break;
1489 case UDyneg:
1490 updir[1] = -1.;
1491 break;
1492 case UDxneg:
1493 updir[0] = -1.;
1494 break;
1495 case UDxpos:
1496 updir[0] = 1.;
1497 break;
1498 case UDypos:
1499 updir[1] = 1.;
1500 break;
1501 case UDzpos:
1502 updir[2] = 1.;
1503 break;
1504 case UDunknown:
1505 return(0);
1506 }
1507 fcross(xdest, updir, nrm);
1508 if (normalize(xdest) == 0.0)
1509 return(0);
1510 fcross(ydest, nrm, xdest);
1511 xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs);
1512 copymat4(xm, myxf.xfm);
1513 if (xfbuf == NULL)
1514 return(1);
1515 /* return xf arguments as well */
1516 for (i = 0; xfargs[i] != NULL; i++) {
1517 *xfbuf++ = ' ';
1518 strcpy(xfbuf, xfargs[i]);
1519 while (*xfbuf) ++xfbuf;
1520 }
1521 return(1);
1522 }
1523
1524 /*######### END DEPRECATED ROUTINES #######*/
1525 /*################################################################*/