1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf.c,v 2.34 2011/07/07 15:25:09 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 |
if (df->comp[n].dist != NULL) |
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-6) { /* 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-6) { /* 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 |
|
819 |
#define MAXLATS 46 /* maximum number of latitudes */ |
820 |
|
821 |
/* BSDF angle specification */ |
822 |
typedef struct { |
823 |
char name[64]; /* basis name */ |
824 |
int nangles; /* total number of directions */ |
825 |
struct { |
826 |
float tmin; /* starting theta */ |
827 |
short nphis; /* number of phis (0 term) */ |
828 |
} lat[MAXLATS+1]; /* latitudes */ |
829 |
} ANGLE_BASIS; |
830 |
|
831 |
#define MAXABASES 7 /* limit on defined bases */ |
832 |
|
833 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
834 |
{ |
835 |
"LBNL/Klems Full", 145, |
836 |
{ {-5., 1}, |
837 |
{5., 8}, |
838 |
{15., 16}, |
839 |
{25., 20}, |
840 |
{35., 24}, |
841 |
{45., 24}, |
842 |
{55., 24}, |
843 |
{65., 16}, |
844 |
{75., 12}, |
845 |
{90., 0} } |
846 |
}, { |
847 |
"LBNL/Klems Half", 73, |
848 |
{ {-6.5, 1}, |
849 |
{6.5, 8}, |
850 |
{19.5, 12}, |
851 |
{32.5, 16}, |
852 |
{46.5, 20}, |
853 |
{61.5, 12}, |
854 |
{76.5, 4}, |
855 |
{90., 0} } |
856 |
}, { |
857 |
"LBNL/Klems Quarter", 41, |
858 |
{ {-9., 1}, |
859 |
{9., 8}, |
860 |
{27., 12}, |
861 |
{46., 12}, |
862 |
{66., 8}, |
863 |
{90., 0} } |
864 |
} |
865 |
}; |
866 |
|
867 |
static int nabases = 3; /* current number of defined bases */ |
868 |
|
869 |
#define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6) |
870 |
|
871 |
static int |
872 |
fequal(double a, double b) |
873 |
{ |
874 |
if (b != 0) |
875 |
a = a/b - 1.; |
876 |
return((a <= 1e-6) & (a >= -1e-6)); |
877 |
} |
878 |
|
879 |
/* Returns the name of the given tag */ |
880 |
#ifdef ezxml_name |
881 |
#undef ezxml_name |
882 |
static char * |
883 |
ezxml_name(ezxml_t xml) |
884 |
{ |
885 |
if (xml == NULL) |
886 |
return(NULL); |
887 |
return(xml->name); |
888 |
} |
889 |
#endif |
890 |
|
891 |
/* Returns the given tag's character content or empty string if none */ |
892 |
#ifdef ezxml_txt |
893 |
#undef ezxml_txt |
894 |
static char * |
895 |
ezxml_txt(ezxml_t xml) |
896 |
{ |
897 |
if (xml == NULL) |
898 |
return(""); |
899 |
return(xml->txt); |
900 |
} |
901 |
#endif |
902 |
|
903 |
|
904 |
static int |
905 |
ab_getvec( /* get vector for this angle basis index */ |
906 |
FVECT v, |
907 |
int ndx, |
908 |
void *p |
909 |
) |
910 |
{ |
911 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
912 |
int li; |
913 |
double pol, azi, d; |
914 |
|
915 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
916 |
return(0); |
917 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
918 |
ndx -= ab->lat[li].nphis; |
919 |
pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin); |
920 |
azi = 2.*PI*ndx/ab->lat[li].nphis; |
921 |
v[2] = d = cos(pol); |
922 |
d = sqrt(1. - d*d); /* sin(pol) */ |
923 |
v[0] = cos(azi)*d; |
924 |
v[1] = sin(azi)*d; |
925 |
return(1); |
926 |
} |
927 |
|
928 |
|
929 |
static int |
930 |
ab_getndx( /* get index corresponding to the given vector */ |
931 |
FVECT v, |
932 |
void *p |
933 |
) |
934 |
{ |
935 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
936 |
int li, ndx; |
937 |
double pol, azi; |
938 |
|
939 |
if ((v[2] < -1.0) | (v[2] > 1.0)) |
940 |
return(-1); |
941 |
pol = 180.0/PI*acos(v[2]); |
942 |
azi = 180.0/PI*atan2(v[1], v[0]); |
943 |
if (azi < 0.0) azi += 360.0; |
944 |
for (li = 1; ab->lat[li].tmin <= pol; li++) |
945 |
if (!ab->lat[li].nphis) |
946 |
return(-1); |
947 |
--li; |
948 |
ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
949 |
if (ndx >= ab->lat[li].nphis) ndx = 0; |
950 |
while (li--) |
951 |
ndx += ab->lat[li].nphis; |
952 |
return(ndx); |
953 |
} |
954 |
|
955 |
|
956 |
static double |
957 |
ab_getohm( /* get solid angle for this angle basis index */ |
958 |
int ndx, |
959 |
void *p |
960 |
) |
961 |
{ |
962 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
963 |
int li; |
964 |
double theta, theta1; |
965 |
|
966 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
967 |
return(0); |
968 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
969 |
ndx -= ab->lat[li].nphis; |
970 |
theta1 = PI/180. * ab->lat[li+1].tmin; |
971 |
if (ab->lat[li].nphis == 1) { /* special case */ |
972 |
if (ab->lat[li].tmin > FTINY) |
973 |
error(USER, "unsupported BSDF coordinate system"); |
974 |
return(2.*PI*(1. - cos(theta1))); |
975 |
} |
976 |
theta = PI/180. * ab->lat[li].tmin; |
977 |
return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis); |
978 |
} |
979 |
|
980 |
|
981 |
static int |
982 |
ab_getvecR( /* get reverse vector for this angle basis index */ |
983 |
FVECT v, |
984 |
int ndx, |
985 |
void *p |
986 |
) |
987 |
{ |
988 |
if (!ab_getvec(v, ndx, p)) |
989 |
return(0); |
990 |
|
991 |
v[0] = -v[0]; |
992 |
v[1] = -v[1]; |
993 |
v[2] = -v[2]; |
994 |
|
995 |
return(1); |
996 |
} |
997 |
|
998 |
|
999 |
static int |
1000 |
ab_getndxR( /* get index corresponding to the reverse vector */ |
1001 |
FVECT v, |
1002 |
void *p |
1003 |
) |
1004 |
{ |
1005 |
FVECT v2; |
1006 |
|
1007 |
v2[0] = -v[0]; |
1008 |
v2[1] = -v[1]; |
1009 |
v2[2] = -v[2]; |
1010 |
|
1011 |
return ab_getndx(v2, p); |
1012 |
} |
1013 |
|
1014 |
|
1015 |
static void |
1016 |
load_angle_basis( /* load custom BSDF angle basis */ |
1017 |
ezxml_t wab |
1018 |
) |
1019 |
{ |
1020 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
1021 |
ezxml_t wbb; |
1022 |
int i; |
1023 |
|
1024 |
if (!abname || !*abname) |
1025 |
return; |
1026 |
for (i = nabases; i--; ) |
1027 |
if (!strcasecmp(abname, abase_list[i].name)) |
1028 |
return; /* assume it's the same */ |
1029 |
if (nabases >= MAXABASES) |
1030 |
error(INTERNAL, "too many angle bases"); |
1031 |
strcpy(abase_list[nabases].name, abname); |
1032 |
abase_list[nabases].nangles = 0; |
1033 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
1034 |
wbb != NULL; i++, wbb = wbb->next) { |
1035 |
if (i >= MAXLATS) |
1036 |
error(INTERNAL, "too many latitudes in custom basis"); |
1037 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
1038 |
ezxml_child(ezxml_child(wbb, |
1039 |
"ThetaBounds"), "UpperTheta"))); |
1040 |
if (!i) |
1041 |
abase_list[nabases].lat[i].tmin = |
1042 |
-abase_list[nabases].lat[i+1].tmin; |
1043 |
else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
1044 |
"ThetaBounds"), "LowerTheta"))), |
1045 |
abase_list[nabases].lat[i].tmin)) |
1046 |
error(WARNING, "theta values disagree in custom basis"); |
1047 |
abase_list[nabases].nangles += |
1048 |
abase_list[nabases].lat[i].nphis = |
1049 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
1050 |
} |
1051 |
abase_list[nabases++].lat[i].nphis = 0; |
1052 |
} |
1053 |
|
1054 |
|
1055 |
static void |
1056 |
load_geometry( /* load geometric dimensions and description (if any) */ |
1057 |
struct BSDF_data *dp, |
1058 |
ezxml_t wdb |
1059 |
) |
1060 |
{ |
1061 |
ezxml_t geom; |
1062 |
double cfact; |
1063 |
const char *fmt, *mgfstr; |
1064 |
|
1065 |
dp->dim[0] = dp->dim[1] = dp->dim[2] = 0; |
1066 |
dp->mgf = NULL; |
1067 |
if ((geom = ezxml_child(wdb, "Width")) != NULL) |
1068 |
dp->dim[0] = atof(ezxml_txt(geom)) * |
1069 |
to_meters(ezxml_attr(geom, "unit")); |
1070 |
if ((geom = ezxml_child(wdb, "Height")) != NULL) |
1071 |
dp->dim[1] = atof(ezxml_txt(geom)) * |
1072 |
to_meters(ezxml_attr(geom, "unit")); |
1073 |
if ((geom = ezxml_child(wdb, "Thickness")) != NULL) |
1074 |
dp->dim[2] = atof(ezxml_txt(geom)) * |
1075 |
to_meters(ezxml_attr(geom, "unit")); |
1076 |
if ((geom = ezxml_child(wdb, "Geometry")) == NULL || |
1077 |
(mgfstr = ezxml_txt(geom)) == NULL) |
1078 |
return; |
1079 |
if ((fmt = ezxml_attr(geom, "format")) != NULL && |
1080 |
strcasecmp(fmt, "MGF")) { |
1081 |
sprintf(errmsg, "unrecognized geometry format '%s'", fmt); |
1082 |
error(WARNING, errmsg); |
1083 |
return; |
1084 |
} |
1085 |
cfact = to_meters(ezxml_attr(geom, "unit")); |
1086 |
dp->mgf = (char *)malloc(strlen(mgfstr)+32); |
1087 |
if (dp->mgf == NULL) |
1088 |
error(SYSTEM, "out of memory in load_geometry"); |
1089 |
if (cfact < 0.99 || cfact > 1.01) |
1090 |
sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
1091 |
else |
1092 |
strcpy(dp->mgf, mgfstr); |
1093 |
} |
1094 |
|
1095 |
|
1096 |
static void |
1097 |
load_bsdf_data( /* load BSDF distribution for this wavelength */ |
1098 |
struct BSDF_data *dp, |
1099 |
ezxml_t wdb |
1100 |
) |
1101 |
{ |
1102 |
char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
1103 |
char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
1104 |
char *sdata; |
1105 |
int i; |
1106 |
|
1107 |
if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) { |
1108 |
error(WARNING, "missing column/row basis for BSDF"); |
1109 |
return; |
1110 |
} |
1111 |
for (i = nabases; i--; ) |
1112 |
if (!strcasecmp(cbasis, abase_list[i].name)) { |
1113 |
dp->ninc = abase_list[i].nangles; |
1114 |
dp->ib_priv = (void *)&abase_list[i]; |
1115 |
dp->ib_vec = ab_getvecR; |
1116 |
dp->ib_ndx = ab_getndxR; |
1117 |
dp->ib_ohm = ab_getohm; |
1118 |
break; |
1119 |
} |
1120 |
if (i < 0) { |
1121 |
sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis); |
1122 |
error(WARNING, errmsg); |
1123 |
return; |
1124 |
} |
1125 |
for (i = nabases; i--; ) |
1126 |
if (!strcasecmp(rbasis, abase_list[i].name)) { |
1127 |
dp->nout = abase_list[i].nangles; |
1128 |
dp->ob_priv = (void *)&abase_list[i]; |
1129 |
dp->ob_vec = ab_getvec; |
1130 |
dp->ob_ndx = ab_getndx; |
1131 |
dp->ob_ohm = ab_getohm; |
1132 |
break; |
1133 |
} |
1134 |
if (i < 0) { |
1135 |
sprintf(errmsg, "undefined RowAngleBasis '%s'", rbasis); |
1136 |
error(WARNING, errmsg); |
1137 |
return; |
1138 |
} |
1139 |
/* read BSDF data */ |
1140 |
sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData")); |
1141 |
if (!sdata || !*sdata) { |
1142 |
error(WARNING, "missing BSDF ScatteringData"); |
1143 |
return; |
1144 |
} |
1145 |
dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout); |
1146 |
if (dp->bsdf == NULL) |
1147 |
error(SYSTEM, "out of memory in load_bsdf_data"); |
1148 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
1149 |
char *sdnext = fskip(sdata); |
1150 |
if (sdnext == NULL) { |
1151 |
error(WARNING, "bad/missing BSDF ScatteringData"); |
1152 |
free(dp->bsdf); dp->bsdf = NULL; |
1153 |
return; |
1154 |
} |
1155 |
while (*sdnext && isspace(*sdnext)) |
1156 |
sdnext++; |
1157 |
if (*sdnext == ',') sdnext++; |
1158 |
dp->bsdf[i] = atof(sdata); |
1159 |
sdata = sdnext; |
1160 |
} |
1161 |
while (isspace(*sdata)) |
1162 |
sdata++; |
1163 |
if (*sdata) { |
1164 |
sprintf(errmsg, "%d extra characters after BSDF ScatteringData", |
1165 |
(int)strlen(sdata)); |
1166 |
error(WARNING, errmsg); |
1167 |
} |
1168 |
} |
1169 |
|
1170 |
|
1171 |
static int |
1172 |
check_bsdf_data( /* check that BSDF data is sane */ |
1173 |
struct BSDF_data *dp |
1174 |
) |
1175 |
{ |
1176 |
double *omega_iarr, *omega_oarr; |
1177 |
double dom, hemi_total, full_total; |
1178 |
int nneg; |
1179 |
FVECT v; |
1180 |
int i, o; |
1181 |
|
1182 |
if (dp == NULL || dp->bsdf == NULL) |
1183 |
return(0); |
1184 |
omega_iarr = (double *)calloc(dp->ninc, sizeof(double)); |
1185 |
omega_oarr = (double *)calloc(dp->nout, sizeof(double)); |
1186 |
if ((omega_iarr == NULL) | (omega_oarr == NULL)) |
1187 |
error(SYSTEM, "out of memory in check_bsdf_data"); |
1188 |
/* incoming projected solid angles */ |
1189 |
hemi_total = .0; |
1190 |
for (i = dp->ninc; i--; ) { |
1191 |
dom = getBSDF_incohm(dp,i); |
1192 |
if (dom <= 0) { |
1193 |
error(WARNING, "zero/negative incoming solid angle"); |
1194 |
continue; |
1195 |
} |
1196 |
if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) { |
1197 |
error(WARNING, "illegal incoming BSDF direction"); |
1198 |
free(omega_iarr); free(omega_oarr); |
1199 |
return(0); |
1200 |
} |
1201 |
hemi_total += omega_iarr[i] = dom * -v[2]; |
1202 |
} |
1203 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
1204 |
sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%", |
1205 |
100.*(hemi_total/PI - 1.)); |
1206 |
error(WARNING, errmsg); |
1207 |
} |
1208 |
dom = PI / hemi_total; /* fix normalization */ |
1209 |
for (i = dp->ninc; i--; ) |
1210 |
omega_iarr[i] *= dom; |
1211 |
/* outgoing projected solid angles */ |
1212 |
hemi_total = .0; |
1213 |
for (o = dp->nout; o--; ) { |
1214 |
dom = getBSDF_outohm(dp,o); |
1215 |
if (dom <= 0) { |
1216 |
error(WARNING, "zero/negative outgoing solid angle"); |
1217 |
continue; |
1218 |
} |
1219 |
if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) { |
1220 |
error(WARNING, "illegal outgoing BSDF direction"); |
1221 |
free(omega_iarr); free(omega_oarr); |
1222 |
return(0); |
1223 |
} |
1224 |
hemi_total += omega_oarr[o] = dom * v[2]; |
1225 |
} |
1226 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
1227 |
sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%", |
1228 |
100.*(hemi_total/PI - 1.)); |
1229 |
error(WARNING, errmsg); |
1230 |
} |
1231 |
dom = PI / hemi_total; /* fix normalization */ |
1232 |
for (o = dp->nout; o--; ) |
1233 |
omega_oarr[o] *= dom; |
1234 |
nneg = 0; /* check outgoing totals */ |
1235 |
for (i = 0; i < dp->ninc; i++) { |
1236 |
hemi_total = .0; |
1237 |
for (o = dp->nout; o--; ) { |
1238 |
double f = BSDF_value(dp,i,o); |
1239 |
if (f >= 0) |
1240 |
hemi_total += f*omega_oarr[o]; |
1241 |
else { |
1242 |
nneg += (f < -FTINY); |
1243 |
BSDF_value(dp,i,o) = .0f; |
1244 |
} |
1245 |
} |
1246 |
if (hemi_total > 1.01) { |
1247 |
sprintf(errmsg, |
1248 |
"incoming BSDF direction %d passes %.1f%% of light", |
1249 |
i, 100.*hemi_total); |
1250 |
error(WARNING, errmsg); |
1251 |
} |
1252 |
} |
1253 |
if (nneg) { |
1254 |
sprintf(errmsg, "%d negative BSDF values (ignored)", nneg); |
1255 |
error(WARNING, errmsg); |
1256 |
} |
1257 |
full_total = .0; /* reverse roles and check again */ |
1258 |
for (o = 0; o < dp->nout; o++) { |
1259 |
hemi_total = .0; |
1260 |
for (i = dp->ninc; i--; ) |
1261 |
hemi_total += BSDF_value(dp,i,o) * omega_iarr[i]; |
1262 |
|
1263 |
if (hemi_total > 1.01) { |
1264 |
sprintf(errmsg, |
1265 |
"outgoing BSDF direction %d collects %.1f%% of light", |
1266 |
o, 100.*hemi_total); |
1267 |
error(WARNING, errmsg); |
1268 |
} |
1269 |
full_total += hemi_total*omega_oarr[o]; |
1270 |
} |
1271 |
full_total /= PI; |
1272 |
if (full_total > 1.00001) { |
1273 |
sprintf(errmsg, "BSDF transfers %.4f%% of light", |
1274 |
100.*full_total); |
1275 |
error(WARNING, errmsg); |
1276 |
} |
1277 |
free(omega_iarr); free(omega_oarr); |
1278 |
return(1); |
1279 |
} |
1280 |
|
1281 |
|
1282 |
struct BSDF_data * |
1283 |
load_BSDF( /* load BSDF data from file */ |
1284 |
char *fname |
1285 |
) |
1286 |
{ |
1287 |
char *path; |
1288 |
ezxml_t fl, wtl, wld, wdb; |
1289 |
struct BSDF_data *dp; |
1290 |
|
1291 |
path = getpath(fname, getrlibpath(), R_OK); |
1292 |
if (path == NULL) { |
1293 |
sprintf(errmsg, "cannot find BSDF file \"%s\"", fname); |
1294 |
error(WARNING, errmsg); |
1295 |
return(NULL); |
1296 |
} |
1297 |
fl = ezxml_parse_file(path); |
1298 |
if (fl == NULL) { |
1299 |
sprintf(errmsg, "cannot open BSDF \"%s\"", path); |
1300 |
error(WARNING, errmsg); |
1301 |
return(NULL); |
1302 |
} |
1303 |
if (ezxml_error(fl)[0]) { |
1304 |
sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl)); |
1305 |
error(WARNING, errmsg); |
1306 |
ezxml_free(fl); |
1307 |
return(NULL); |
1308 |
} |
1309 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
1310 |
sprintf(errmsg, |
1311 |
"BSDF \"%s\": top level node not 'WindowElement'", |
1312 |
path); |
1313 |
error(WARNING, errmsg); |
1314 |
ezxml_free(fl); |
1315 |
return(NULL); |
1316 |
} |
1317 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
1318 |
if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl, |
1319 |
"DataDefinition"), "IncidentDataStructure")), |
1320 |
"Columns")) { |
1321 |
sprintf(errmsg, |
1322 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
1323 |
path); |
1324 |
error(WARNING, errmsg); |
1325 |
ezxml_free(fl); |
1326 |
return(NULL); |
1327 |
} |
1328 |
for (wld = ezxml_child(ezxml_child(wtl, |
1329 |
"DataDefinition"), "AngleBasis"); |
1330 |
wld != NULL; wld = wld->next) |
1331 |
load_angle_basis(wld); |
1332 |
dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
1333 |
load_geometry(dp, ezxml_child(wtl, "Material")); |
1334 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
1335 |
wld != NULL; wld = wld->next) { |
1336 |
if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")), |
1337 |
"Visible")) |
1338 |
continue; |
1339 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
1340 |
wdb != NULL; wdb = wdb->next) |
1341 |
if (!strcasecmp(ezxml_txt(ezxml_child(wdb, |
1342 |
"WavelengthDataDirection")), |
1343 |
"Transmission Front")) |
1344 |
break; |
1345 |
if (wdb != NULL) { /* load front BTDF */ |
1346 |
load_bsdf_data(dp, wdb); |
1347 |
break; /* ignore the rest */ |
1348 |
} |
1349 |
} |
1350 |
ezxml_free(fl); /* done with XML file */ |
1351 |
if (!check_bsdf_data(dp)) { |
1352 |
sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path); |
1353 |
error(WARNING, errmsg); |
1354 |
free_BSDF(dp); |
1355 |
dp = NULL; |
1356 |
} |
1357 |
return(dp); |
1358 |
} |
1359 |
|
1360 |
|
1361 |
void |
1362 |
free_BSDF( /* free BSDF data structure */ |
1363 |
struct BSDF_data *b |
1364 |
) |
1365 |
{ |
1366 |
if (b == NULL) |
1367 |
return; |
1368 |
if (b->mgf != NULL) |
1369 |
free(b->mgf); |
1370 |
if (b->bsdf != NULL) |
1371 |
free(b->bsdf); |
1372 |
free(b); |
1373 |
} |
1374 |
|
1375 |
|
1376 |
int |
1377 |
r_BSDF_incvec( /* compute random input vector at given location */ |
1378 |
FVECT v, |
1379 |
struct BSDF_data *b, |
1380 |
int i, |
1381 |
double rv, |
1382 |
MAT4 xm |
1383 |
) |
1384 |
{ |
1385 |
FVECT pert; |
1386 |
double rad; |
1387 |
int j; |
1388 |
|
1389 |
if (!getBSDF_incvec(v, b, i)) |
1390 |
return(0); |
1391 |
rad = sqrt(getBSDF_incohm(b, i) / PI); |
1392 |
multisamp(pert, 3, rv); |
1393 |
for (j = 0; j < 3; j++) |
1394 |
v[j] += rad*(2.*pert[j] - 1.); |
1395 |
if (xm != NULL) |
1396 |
multv3(v, v, xm); |
1397 |
return(normalize(v) != 0.0); |
1398 |
} |
1399 |
|
1400 |
|
1401 |
int |
1402 |
r_BSDF_outvec( /* compute random output vector at given location */ |
1403 |
FVECT v, |
1404 |
struct BSDF_data *b, |
1405 |
int o, |
1406 |
double rv, |
1407 |
MAT4 xm |
1408 |
) |
1409 |
{ |
1410 |
FVECT pert; |
1411 |
double rad; |
1412 |
int j; |
1413 |
|
1414 |
if (!getBSDF_outvec(v, b, o)) |
1415 |
return(0); |
1416 |
rad = sqrt(getBSDF_outohm(b, o) / PI); |
1417 |
multisamp(pert, 3, rv); |
1418 |
for (j = 0; j < 3; j++) |
1419 |
v[j] += rad*(2.*pert[j] - 1.); |
1420 |
if (xm != NULL) |
1421 |
multv3(v, v, xm); |
1422 |
return(normalize(v) != 0.0); |
1423 |
} |
1424 |
|
1425 |
|
1426 |
static int |
1427 |
addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
1428 |
char *xfarg[], |
1429 |
FVECT xp, |
1430 |
FVECT yp, |
1431 |
FVECT zp |
1432 |
) |
1433 |
{ |
1434 |
static char bufs[3][16]; |
1435 |
int bn = 0; |
1436 |
char **xfp = xfarg; |
1437 |
double theta; |
1438 |
|
1439 |
if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) { |
1440 |
/* Special case for X' along Z-axis */ |
1441 |
theta = -atan2(yp[0], yp[1]); |
1442 |
*xfp++ = "-ry"; |
1443 |
*xfp++ = xp[2] < 0.0 ? "90" : "-90"; |
1444 |
*xfp++ = "-rz"; |
1445 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1446 |
*xfp++ = bufs[bn++]; |
1447 |
return(xfp - xfarg); |
1448 |
} |
1449 |
theta = atan2(yp[2], zp[2]); |
1450 |
if (!FEQ(theta,0.0)) { |
1451 |
*xfp++ = "-rx"; |
1452 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1453 |
*xfp++ = bufs[bn++]; |
1454 |
} |
1455 |
theta = asin(-xp[2]); |
1456 |
if (!FEQ(theta,0.0)) { |
1457 |
*xfp++ = "-ry"; |
1458 |
sprintf(bufs[bn], " %f", theta*(180./PI)); |
1459 |
*xfp++ = bufs[bn++]; |
1460 |
} |
1461 |
theta = atan2(xp[1], xp[0]); |
1462 |
if (!FEQ(theta,0.0)) { |
1463 |
*xfp++ = "-rz"; |
1464 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1465 |
*xfp++ = bufs[bn++]; |
1466 |
} |
1467 |
*xfp = NULL; |
1468 |
return(xfp - xfarg); |
1469 |
} |
1470 |
|
1471 |
|
1472 |
int |
1473 |
getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */ |
1474 |
MAT4 xm, |
1475 |
FVECT nrm, |
1476 |
UpDir ud, |
1477 |
char *xfbuf |
1478 |
) |
1479 |
{ |
1480 |
char *xfargs[7]; |
1481 |
XF myxf; |
1482 |
FVECT updir, xdest, ydest; |
1483 |
int i; |
1484 |
|
1485 |
updir[0] = updir[1] = updir[2] = 0.; |
1486 |
switch (ud) { |
1487 |
case UDzneg: |
1488 |
updir[2] = -1.; |
1489 |
break; |
1490 |
case UDyneg: |
1491 |
updir[1] = -1.; |
1492 |
break; |
1493 |
case UDxneg: |
1494 |
updir[0] = -1.; |
1495 |
break; |
1496 |
case UDxpos: |
1497 |
updir[0] = 1.; |
1498 |
break; |
1499 |
case UDypos: |
1500 |
updir[1] = 1.; |
1501 |
break; |
1502 |
case UDzpos: |
1503 |
updir[2] = 1.; |
1504 |
break; |
1505 |
case UDunknown: |
1506 |
return(0); |
1507 |
} |
1508 |
fcross(xdest, updir, nrm); |
1509 |
if (normalize(xdest) == 0.0) |
1510 |
return(0); |
1511 |
fcross(ydest, nrm, xdest); |
1512 |
xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
1513 |
copymat4(xm, myxf.xfm); |
1514 |
if (xfbuf == NULL) |
1515 |
return(1); |
1516 |
/* return xf arguments as well */ |
1517 |
for (i = 0; xfargs[i] != NULL; i++) { |
1518 |
*xfbuf++ = ' '; |
1519 |
strcpy(xfbuf, xfargs[i]); |
1520 |
while (*xfbuf) ++xfbuf; |
1521 |
} |
1522 |
return(1); |
1523 |
} |
1524 |
|
1525 |
/*######### END DEPRECATED ROUTINES #######*/ |
1526 |
/*################################################################*/ |