1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf.c,v 2.21 2011/04/17 17:45:13 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\"", |
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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) |
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sprintf(sd->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
124 |
else |
125 |
strcpy(sd->mgf, mgfstr); |
126 |
return SDEnone; |
127 |
} |
128 |
|
129 |
/* Load a BSDF struct from the given file (free first and keep name) */ |
130 |
SDError |
131 |
SDloadFile(SDData *sd, const char *fname) |
132 |
{ |
133 |
SDError lastErr; |
134 |
ezxml_t fl, wtl; |
135 |
|
136 |
if ((sd == NULL) | (fname == NULL || !*fname)) |
137 |
return SDEargument; |
138 |
/* free old data, keeping name */ |
139 |
SDfreeBSDF(sd); |
140 |
/* parse XML file */ |
141 |
fl = ezxml_parse_file(fname); |
142 |
if (fl == NULL) { |
143 |
sprintf(SDerrorDetail, "Cannot open BSDF \"%s\"", fname); |
144 |
return SDEfile; |
145 |
} |
146 |
if (ezxml_error(fl)[0]) { |
147 |
sprintf(SDerrorDetail, "BSDF \"%s\" %s", fname, ezxml_error(fl)); |
148 |
ezxml_free(fl); |
149 |
return SDEformat; |
150 |
} |
151 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
152 |
sprintf(SDerrorDetail, |
153 |
"BSDF \"%s\": top level node not 'WindowElement'", |
154 |
sd->name); |
155 |
ezxml_free(fl); |
156 |
return SDEformat; |
157 |
} |
158 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
159 |
if (wtl == NULL) { |
160 |
sprintf(SDerrorDetail, "BSDF \"%s\": no optical layer'", |
161 |
sd->name); |
162 |
ezxml_free(fl); |
163 |
return SDEformat; |
164 |
} |
165 |
/* load geometry if present */ |
166 |
lastErr = SDloadGeometry(sd, ezxml_child(wtl, "Material")); |
167 |
if (lastErr) |
168 |
return lastErr; |
169 |
/* try loading variable resolution data */ |
170 |
lastErr = SDloadTre(sd, wtl); |
171 |
/* check our result */ |
172 |
switch (lastErr) { |
173 |
case SDEformat: |
174 |
case SDEdata: |
175 |
case SDEsupport: /* possibly we just tried the wrong format */ |
176 |
lastErr = SDloadMtx(sd, wtl); |
177 |
break; |
178 |
default: /* variable res. OK else serious error */ |
179 |
break; |
180 |
} |
181 |
/* done with XML file */ |
182 |
ezxml_free(fl); |
183 |
|
184 |
if (lastErr) { /* was there a load error? */ |
185 |
SDfreeBSDF(sd); |
186 |
return lastErr; |
187 |
} |
188 |
/* remove any insignificant components */ |
189 |
if (sd->rf != NULL && sd->rf->maxHemi <= .001) { |
190 |
SDfreeSpectralDF(sd->rf); sd->rf = NULL; |
191 |
} |
192 |
if (sd->rb != NULL && sd->rb->maxHemi <= .001) { |
193 |
SDfreeSpectralDF(sd->rb); sd->rb = NULL; |
194 |
} |
195 |
if (sd->tf != NULL && sd->tf->maxHemi <= .001) { |
196 |
SDfreeSpectralDF(sd->tf); sd->tf = NULL; |
197 |
} |
198 |
/* return success */ |
199 |
return SDEnone; |
200 |
} |
201 |
|
202 |
/* Allocate new spectral distribution function */ |
203 |
SDSpectralDF * |
204 |
SDnewSpectralDF(int nc) |
205 |
{ |
206 |
SDSpectralDF *df; |
207 |
|
208 |
if (nc <= 0) { |
209 |
strcpy(SDerrorDetail, "Zero component spectral DF request"); |
210 |
return NULL; |
211 |
} |
212 |
df = (SDSpectralDF *)malloc(sizeof(SDSpectralDF) + |
213 |
(nc-1)*sizeof(SDComponent)); |
214 |
if (df == NULL) { |
215 |
sprintf(SDerrorDetail, |
216 |
"Cannot allocate %d component spectral DF", nc); |
217 |
return NULL; |
218 |
} |
219 |
df->minProjSA = .0; |
220 |
df->maxHemi = .0; |
221 |
df->ncomp = nc; |
222 |
memset(df->comp, 0, nc*sizeof(SDComponent)); |
223 |
return df; |
224 |
} |
225 |
|
226 |
/* Free cached cumulative distributions for BSDF component */ |
227 |
void |
228 |
SDfreeCumulativeCache(SDSpectralDF *df) |
229 |
{ |
230 |
int n; |
231 |
SDCDst *cdp; |
232 |
|
233 |
if (df == NULL) |
234 |
return; |
235 |
for (n = df->ncomp; n-- > 0; ) |
236 |
while ((cdp = df->comp[n].cdList) != NULL) { |
237 |
df->comp[n].cdList = cdp->next; |
238 |
free(cdp); |
239 |
} |
240 |
} |
241 |
|
242 |
/* Free a spectral distribution function */ |
243 |
void |
244 |
SDfreeSpectralDF(SDSpectralDF *df) |
245 |
{ |
246 |
int n; |
247 |
|
248 |
if (df == NULL) |
249 |
return; |
250 |
SDfreeCumulativeCache(df); |
251 |
for (n = df->ncomp; n-- > 0; ) |
252 |
(*df->comp[n].func->freeSC)(df->comp[n].dist); |
253 |
free(df); |
254 |
} |
255 |
|
256 |
/* Shorten file path to useable BSDF name, removing suffix */ |
257 |
void |
258 |
SDclipName(char *res, const char *fname) |
259 |
{ |
260 |
const char *cp, *dot = NULL; |
261 |
|
262 |
for (cp = fname; *cp; cp++) |
263 |
if (*cp == '.') |
264 |
dot = cp; |
265 |
if ((dot == NULL) | (dot < fname+2)) |
266 |
dot = cp; |
267 |
if (dot - fname >= SDnameLn) |
268 |
fname = dot - SDnameLn + 1; |
269 |
while (fname < dot) |
270 |
*res++ = *fname++; |
271 |
*res = '\0'; |
272 |
} |
273 |
|
274 |
/* Initialize an unused BSDF struct (simply clears to zeroes) */ |
275 |
void |
276 |
SDclearBSDF(SDData *sd, const char *fname) |
277 |
{ |
278 |
if (sd == NULL) |
279 |
return; |
280 |
memset(sd, 0, sizeof(SDData)); |
281 |
if (fname == NULL) |
282 |
return; |
283 |
SDclipName(sd->name, fname); |
284 |
} |
285 |
|
286 |
/* Free data associated with BSDF struct */ |
287 |
void |
288 |
SDfreeBSDF(SDData *sd) |
289 |
{ |
290 |
if (sd == NULL) |
291 |
return; |
292 |
if (sd->mgf != NULL) { |
293 |
free(sd->mgf); |
294 |
sd->mgf = NULL; |
295 |
} |
296 |
if (sd->rf != NULL) { |
297 |
SDfreeSpectralDF(sd->rf); |
298 |
sd->rf = NULL; |
299 |
} |
300 |
if (sd->rb != NULL) { |
301 |
SDfreeSpectralDF(sd->rb); |
302 |
sd->rb = NULL; |
303 |
} |
304 |
if (sd->tf != NULL) { |
305 |
SDfreeSpectralDF(sd->tf); |
306 |
sd->tf = NULL; |
307 |
} |
308 |
sd->rLambFront.cieY = .0; |
309 |
sd->rLambFront.spec.flags = 0; |
310 |
sd->rLambBack.cieY = .0; |
311 |
sd->rLambBack.spec.flags = 0; |
312 |
sd->tLamb.cieY = .0; |
313 |
sd->tLamb.spec.flags = 0; |
314 |
} |
315 |
|
316 |
/* Find writeable BSDF by name, or allocate new cache entry if absent */ |
317 |
SDData * |
318 |
SDgetCache(const char *bname) |
319 |
{ |
320 |
struct SDCache_s *sdl; |
321 |
char sdnam[SDnameLn]; |
322 |
|
323 |
if (bname == NULL) |
324 |
return NULL; |
325 |
|
326 |
SDclipName(sdnam, bname); |
327 |
for (sdl = SDcacheList; sdl != NULL; sdl = sdl->next) |
328 |
if (!strcmp(sdl->bsdf.name, sdnam)) { |
329 |
sdl->refcnt++; |
330 |
return &sdl->bsdf; |
331 |
} |
332 |
|
333 |
sdl = (struct SDCache_s *)calloc(1, sizeof(struct SDCache_s)); |
334 |
if (sdl == NULL) |
335 |
return NULL; |
336 |
|
337 |
strcpy(sdl->bsdf.name, sdnam); |
338 |
sdl->next = SDcacheList; |
339 |
SDcacheList = sdl; |
340 |
|
341 |
sdl->refcnt = 1; |
342 |
return &sdl->bsdf; |
343 |
} |
344 |
|
345 |
/* Get loaded BSDF from cache (or load and cache it on first call) */ |
346 |
/* Report any problem to stderr and return NULL on failure */ |
347 |
const SDData * |
348 |
SDcacheFile(const char *fname) |
349 |
{ |
350 |
SDData *sd; |
351 |
SDError ec; |
352 |
|
353 |
if (fname == NULL || !*fname) |
354 |
return NULL; |
355 |
SDerrorDetail[0] = '\0'; |
356 |
if ((sd = SDgetCache(fname)) == NULL) { |
357 |
SDreportEnglish(SDEmemory, stderr); |
358 |
return NULL; |
359 |
} |
360 |
if (!SDisLoaded(sd) && (ec = SDloadFile(sd, fname))) { |
361 |
SDreportEnglish(ec, stderr); |
362 |
SDfreeCache(sd); |
363 |
return NULL; |
364 |
} |
365 |
return sd; |
366 |
} |
367 |
|
368 |
/* Free a BSDF from our cache (clear all if NULL) */ |
369 |
void |
370 |
SDfreeCache(const SDData *sd) |
371 |
{ |
372 |
struct SDCache_s *sdl, *sdLast = NULL; |
373 |
|
374 |
if (sd == NULL) { /* free entire list */ |
375 |
while ((sdl = SDcacheList) != NULL) { |
376 |
SDcacheList = sdl->next; |
377 |
SDfreeBSDF(&sdl->bsdf); |
378 |
free(sdl); |
379 |
} |
380 |
return; |
381 |
} |
382 |
for (sdl = SDcacheList; sdl != NULL; sdl = (sdLast=sdl)->next) |
383 |
if (&sdl->bsdf == sd) |
384 |
break; |
385 |
if (sdl == NULL || (sdl->refcnt -= (sdl->refcnt > 0))) |
386 |
return; /* missing or still in use */ |
387 |
/* keep unreferenced data? */ |
388 |
if (SDisLoaded(sd) && SDretainSet) { |
389 |
if (SDretainSet == SDretainAll) |
390 |
return; /* keep everything */ |
391 |
/* else free cumulative data */ |
392 |
SDfreeCumulativeCache(sd->rf); |
393 |
SDfreeCumulativeCache(sd->rb); |
394 |
SDfreeCumulativeCache(sd->tf); |
395 |
return; |
396 |
} |
397 |
/* remove from list and free */ |
398 |
if (sdLast == NULL) |
399 |
SDcacheList = sdl->next; |
400 |
else |
401 |
sdLast->next = sdl->next; |
402 |
SDfreeBSDF(&sdl->bsdf); |
403 |
free(sdl); |
404 |
} |
405 |
|
406 |
/* Sample an individual BSDF component */ |
407 |
SDError |
408 |
SDsampComponent(SDValue *sv, FVECT outVec, const FVECT inVec, |
409 |
double randX, SDComponent *sdc) |
410 |
{ |
411 |
float coef[SDmaxCh]; |
412 |
SDError ec; |
413 |
const SDCDst *cd; |
414 |
double d; |
415 |
int n; |
416 |
/* check arguments */ |
417 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sdc == NULL)) |
418 |
return SDEargument; |
419 |
/* get cumulative distribution */ |
420 |
cd = (*sdc->func->getCDist)(inVec, sdc); |
421 |
if (cd == NULL) |
422 |
return SDEmemory; |
423 |
if (cd->cTotal <= 1e-7) { /* anything to sample? */ |
424 |
sv->spec = c_dfcolor; |
425 |
sv->cieY = .0; |
426 |
memset(outVec, 0, 3*sizeof(double)); |
427 |
return SDEnone; |
428 |
} |
429 |
sv->cieY = cd->cTotal; |
430 |
/* compute sample direction */ |
431 |
ec = (*sdc->func->sampCDist)(outVec, randX, cd); |
432 |
if (ec) |
433 |
return ec; |
434 |
/* get BSDF color */ |
435 |
n = (*sdc->func->getBSDFs)(coef, outVec, inVec, sdc->dist); |
436 |
if (n <= 0) { |
437 |
strcpy(SDerrorDetail, "BSDF sample value error"); |
438 |
return SDEinternal; |
439 |
} |
440 |
sv->spec = sdc->cspec[0]; |
441 |
d = coef[0]; |
442 |
while (--n) { |
443 |
c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]); |
444 |
d += coef[n]; |
445 |
} |
446 |
/* make sure everything is set */ |
447 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
448 |
return SDEnone; |
449 |
} |
450 |
|
451 |
#define MS_MAXDIM 15 |
452 |
|
453 |
/* Convert 1-dimensional random variable to N-dimensional */ |
454 |
void |
455 |
SDmultiSamp(double t[], int n, double randX) |
456 |
{ |
457 |
unsigned nBits; |
458 |
double scale; |
459 |
bitmask_t ndx, coord[MS_MAXDIM]; |
460 |
|
461 |
while (n > MS_MAXDIM) /* punt for higher dimensions */ |
462 |
t[--n] = rand()*(1./(RAND_MAX+.5)); |
463 |
nBits = (8*sizeof(bitmask_t) - 1) / n; |
464 |
ndx = randX * (double)((bitmask_t)1 << (nBits*n)); |
465 |
/* get coordinate on Hilbert curve */ |
466 |
hilbert_i2c(n, nBits, ndx, coord); |
467 |
/* convert back to [0,1) range */ |
468 |
scale = 1. / (double)((bitmask_t)1 << nBits); |
469 |
while (n--) |
470 |
t[n] = scale * ((double)coord[n] + rand()*(1./(RAND_MAX+.5))); |
471 |
} |
472 |
|
473 |
#undef MS_MAXDIM |
474 |
|
475 |
/* Generate diffuse hemispherical sample */ |
476 |
static void |
477 |
SDdiffuseSamp(FVECT outVec, int outFront, double randX) |
478 |
{ |
479 |
/* convert to position on hemisphere */ |
480 |
SDmultiSamp(outVec, 2, randX); |
481 |
SDsquare2disk(outVec, outVec[0], outVec[1]); |
482 |
outVec[2] = 1. - outVec[0]*outVec[0] - outVec[1]*outVec[1]; |
483 |
if (outVec[2] > .0) /* a bit of paranoia */ |
484 |
outVec[2] = sqrt(outVec[2]); |
485 |
if (!outFront) /* going out back? */ |
486 |
outVec[2] = -outVec[2]; |
487 |
} |
488 |
|
489 |
/* Query projected solid angle coverage for non-diffuse BSDF direction */ |
490 |
SDError |
491 |
SDsizeBSDF(double *projSA, const FVECT v1, const RREAL *v2, |
492 |
int qflags, const SDData *sd) |
493 |
{ |
494 |
SDSpectralDF *rdf; |
495 |
SDError ec; |
496 |
int i; |
497 |
/* check arguments */ |
498 |
if ((projSA == NULL) | (v1 == NULL)) |
499 |
return SDEargument; |
500 |
/* initialize extrema */ |
501 |
switch (qflags) { |
502 |
case SDqueryMax: |
503 |
projSA[0] = .0; |
504 |
break; |
505 |
case SDqueryMin+SDqueryMax: |
506 |
projSA[1] = .0; |
507 |
/* fall through */ |
508 |
case SDqueryMin: |
509 |
projSA[0] = 10.; |
510 |
break; |
511 |
case 0: |
512 |
return SDEargument; |
513 |
} |
514 |
if (v1[2] > .0) /* front surface query? */ |
515 |
rdf = sd->rf; |
516 |
else |
517 |
rdf = sd->rb; |
518 |
ec = SDEdata; /* run through components */ |
519 |
for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) { |
520 |
ec = (*rdf->comp[i].func->queryProjSA)(projSA, v1, v2, |
521 |
qflags, rdf->comp[i].dist); |
522 |
if (ec) |
523 |
return ec; |
524 |
} |
525 |
for (i = (sd->tf==NULL) ? 0 : sd->tf->ncomp; i--; ) { |
526 |
ec = (*sd->tf->comp[i].func->queryProjSA)(projSA, v1, v2, |
527 |
qflags, sd->tf->comp[i].dist); |
528 |
if (ec) |
529 |
return ec; |
530 |
} |
531 |
if (ec) { /* all diffuse? */ |
532 |
projSA[0] = M_PI; |
533 |
if (qflags == SDqueryMin+SDqueryMax) |
534 |
projSA[1] = M_PI; |
535 |
} |
536 |
return SDEnone; |
537 |
} |
538 |
|
539 |
/* Return BSDF for the given incident and scattered ray vectors */ |
540 |
SDError |
541 |
SDevalBSDF(SDValue *sv, const FVECT outVec, const FVECT inVec, const SDData *sd) |
542 |
{ |
543 |
int inFront, outFront; |
544 |
SDSpectralDF *sdf; |
545 |
float coef[SDmaxCh]; |
546 |
int nch, i; |
547 |
/* check arguments */ |
548 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL)) |
549 |
return SDEargument; |
550 |
/* whose side are we on? */ |
551 |
inFront = (inVec[2] > .0); |
552 |
outFront = (outVec[2] > .0); |
553 |
/* start with diffuse portion */ |
554 |
if (inFront & outFront) { |
555 |
*sv = sd->rLambFront; |
556 |
sdf = sd->rf; |
557 |
} else if (!(inFront | outFront)) { |
558 |
*sv = sd->rLambBack; |
559 |
sdf = sd->rb; |
560 |
} else /* inFront ^ outFront */ { |
561 |
*sv = sd->tLamb; |
562 |
sdf = sd->tf; |
563 |
} |
564 |
sv->cieY *= 1./M_PI; |
565 |
/* add non-diffuse components */ |
566 |
i = (sdf != NULL) ? sdf->ncomp : 0; |
567 |
while (i-- > 0) { |
568 |
nch = (*sdf->comp[i].func->getBSDFs)(coef, outVec, inVec, |
569 |
sdf->comp[i].dist); |
570 |
while (nch-- > 0) { |
571 |
c_cmix(&sv->spec, sv->cieY, &sv->spec, |
572 |
coef[nch], &sdf->comp[i].cspec[nch]); |
573 |
sv->cieY += coef[nch]; |
574 |
} |
575 |
} |
576 |
/* make sure everything is set */ |
577 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
578 |
return SDEnone; |
579 |
} |
580 |
|
581 |
/* Compute directional hemispherical scattering at this incident angle */ |
582 |
double |
583 |
SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd) |
584 |
{ |
585 |
double hsum; |
586 |
SDSpectralDF *rdf; |
587 |
const SDCDst *cd; |
588 |
int i; |
589 |
/* check arguments */ |
590 |
if ((inVec == NULL) | (sd == NULL)) |
591 |
return .0; |
592 |
/* gather diffuse components */ |
593 |
if (inVec[2] > .0) { |
594 |
hsum = sd->rLambFront.cieY; |
595 |
rdf = sd->rf; |
596 |
} else /* !inFront */ { |
597 |
hsum = sd->rLambBack.cieY; |
598 |
rdf = sd->rb; |
599 |
} |
600 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
601 |
hsum = .0; |
602 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
603 |
hsum += sd->tLamb.cieY; |
604 |
/* gather non-diffuse components */ |
605 |
i = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR && |
606 |
rdf != NULL) ? rdf->ncomp : 0; |
607 |
while (i-- > 0) { /* non-diffuse reflection */ |
608 |
cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
609 |
if (cd != NULL) |
610 |
hsum += cd->cTotal; |
611 |
} |
612 |
i = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT && |
613 |
sd->tf != NULL) ? sd->tf->ncomp : 0; |
614 |
while (i-- > 0) { /* non-diffuse transmission */ |
615 |
cd = (*sd->tf->comp[i].func->getCDist)(inVec, &sd->tf->comp[i]); |
616 |
if (cd != NULL) |
617 |
hsum += cd->cTotal; |
618 |
} |
619 |
return hsum; |
620 |
} |
621 |
|
622 |
/* Sample BSDF direction based on the given random variable */ |
623 |
SDError |
624 |
SDsampBSDF(SDValue *sv, FVECT outVec, const FVECT inVec, |
625 |
double randX, int sflags, const SDData *sd) |
626 |
{ |
627 |
SDError ec; |
628 |
int inFront; |
629 |
SDSpectralDF *rdf; |
630 |
double rdiff; |
631 |
float coef[SDmaxCh]; |
632 |
int i, j, n, nr; |
633 |
SDComponent *sdc; |
634 |
const SDCDst **cdarr = NULL; |
635 |
/* check arguments */ |
636 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL) | |
637 |
(randX < .0) | (randX >= 1.)) |
638 |
return SDEargument; |
639 |
/* whose side are we on? */ |
640 |
inFront = (inVec[2] > .0); |
641 |
/* remember diffuse portions */ |
642 |
if (inFront) { |
643 |
*sv = sd->rLambFront; |
644 |
rdf = sd->rf; |
645 |
} else /* !inFront */ { |
646 |
*sv = sd->rLambBack; |
647 |
rdf = sd->rb; |
648 |
} |
649 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
650 |
sv->cieY = .0; |
651 |
rdiff = sv->cieY; |
652 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
653 |
sv->cieY += sd->tLamb.cieY; |
654 |
/* gather non-diffuse components */ |
655 |
i = nr = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR && |
656 |
rdf != NULL) ? rdf->ncomp : 0; |
657 |
j = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT && |
658 |
sd->tf != NULL) ? sd->tf->ncomp : 0; |
659 |
n = i + j; |
660 |
if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL) |
661 |
return SDEmemory; |
662 |
while (j-- > 0) { /* non-diffuse transmission */ |
663 |
cdarr[i+j] = (*sd->tf->comp[j].func->getCDist)(inVec, &sd->tf->comp[j]); |
664 |
if (cdarr[i+j] == NULL) { |
665 |
free(cdarr); |
666 |
return SDEmemory; |
667 |
} |
668 |
sv->cieY += cdarr[i+j]->cTotal; |
669 |
} |
670 |
while (i-- > 0) { /* non-diffuse reflection */ |
671 |
cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
672 |
if (cdarr[i] == NULL) { |
673 |
free(cdarr); |
674 |
return SDEmemory; |
675 |
} |
676 |
sv->cieY += cdarr[i]->cTotal; |
677 |
} |
678 |
if (sv->cieY <= 1e-7) { /* anything to sample? */ |
679 |
sv->cieY = .0; |
680 |
memset(outVec, 0, 3*sizeof(double)); |
681 |
return SDEnone; |
682 |
} |
683 |
/* scale random variable */ |
684 |
randX *= sv->cieY; |
685 |
/* diffuse reflection? */ |
686 |
if (randX < rdiff) { |
687 |
SDdiffuseSamp(outVec, inFront, randX/rdiff); |
688 |
goto done; |
689 |
} |
690 |
randX -= rdiff; |
691 |
/* diffuse transmission? */ |
692 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) { |
693 |
if (randX < sd->tLamb.cieY) { |
694 |
sv->spec = sd->tLamb.spec; |
695 |
SDdiffuseSamp(outVec, !inFront, randX/sd->tLamb.cieY); |
696 |
goto done; |
697 |
} |
698 |
randX -= sd->tLamb.cieY; |
699 |
} |
700 |
/* else one of cumulative dist. */ |
701 |
for (i = 0; i < n && randX < cdarr[i]->cTotal; i++) |
702 |
randX -= cdarr[i]->cTotal; |
703 |
if (i >= n) |
704 |
return SDEinternal; |
705 |
/* compute sample direction */ |
706 |
sdc = (i < nr) ? &rdf->comp[i] : &sd->tf->comp[i-nr]; |
707 |
ec = (*sdc->func->sampCDist)(outVec, randX/cdarr[i]->cTotal, cdarr[i]); |
708 |
if (ec) |
709 |
return ec; |
710 |
/* compute color */ |
711 |
j = (*sdc->func->getBSDFs)(coef, outVec, inVec, sdc->dist); |
712 |
if (j <= 0) { |
713 |
sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error", |
714 |
sd->name); |
715 |
return SDEinternal; |
716 |
} |
717 |
sv->spec = sdc->cspec[0]; |
718 |
rdiff = coef[0]; |
719 |
while (--j) { |
720 |
c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]); |
721 |
rdiff += coef[j]; |
722 |
} |
723 |
done: |
724 |
if (cdarr != NULL) |
725 |
free(cdarr); |
726 |
/* make sure everything is set */ |
727 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
728 |
return SDEnone; |
729 |
} |
730 |
|
731 |
/* Compute World->BSDF transform from surface normal and up (Y) vector */ |
732 |
SDError |
733 |
SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec) |
734 |
{ |
735 |
if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL)) |
736 |
return SDEargument; |
737 |
VCOPY(vMtx[2], sNrm); |
738 |
if (normalize(vMtx[2]) == .0) |
739 |
return SDEargument; |
740 |
fcross(vMtx[0], uVec, vMtx[2]); |
741 |
if (normalize(vMtx[0]) == .0) |
742 |
return SDEargument; |
743 |
fcross(vMtx[1], vMtx[2], vMtx[0]); |
744 |
return SDEnone; |
745 |
} |
746 |
|
747 |
/* Compute inverse transform */ |
748 |
SDError |
749 |
SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]) |
750 |
{ |
751 |
RREAL mTmp[3][3]; |
752 |
double d; |
753 |
|
754 |
if ((iMtx == NULL) | (vMtx == NULL)) |
755 |
return SDEargument; |
756 |
/* compute determinant */ |
757 |
mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2]; |
758 |
mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1]; |
759 |
mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2]; |
760 |
d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2]; |
761 |
if (d == .0) { |
762 |
strcpy(SDerrorDetail, "Zero determinant in matrix inversion"); |
763 |
return SDEargument; |
764 |
} |
765 |
d = 1./d; /* invert matrix */ |
766 |
mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d; |
767 |
mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]); |
768 |
mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]); |
769 |
mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]); |
770 |
mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]); |
771 |
mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]); |
772 |
mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]); |
773 |
memcpy(iMtx, mTmp, sizeof(mTmp)); |
774 |
return SDEnone; |
775 |
} |
776 |
|
777 |
/* Transform and normalize direction (column) vector */ |
778 |
SDError |
779 |
SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec) |
780 |
{ |
781 |
FVECT vTmp; |
782 |
|
783 |
if ((resVec == NULL) | (inpVec == NULL)) |
784 |
return SDEargument; |
785 |
if (vMtx == NULL) { /* assume they just want to normalize */ |
786 |
if (resVec != inpVec) |
787 |
VCOPY(resVec, inpVec); |
788 |
return (normalize(resVec) > .0) ? SDEnone : SDEargument; |
789 |
} |
790 |
vTmp[0] = DOT(vMtx[0], inpVec); |
791 |
vTmp[1] = DOT(vMtx[1], inpVec); |
792 |
vTmp[2] = DOT(vMtx[2], inpVec); |
793 |
if (normalize(vTmp) == .0) |
794 |
return SDEargument; |
795 |
VCOPY(resVec, vTmp); |
796 |
return SDEnone; |
797 |
} |
798 |
|
799 |
/*################################################################*/ |
800 |
/*######### DEPRECATED ROUTINES AWAITING PERMANENT REMOVAL #######*/ |
801 |
|
802 |
/* |
803 |
* Routines for handling BSDF data |
804 |
*/ |
805 |
|
806 |
#include "standard.h" |
807 |
#include "paths.h" |
808 |
#include <ctype.h> |
809 |
|
810 |
#define MAXLATS 46 /* maximum number of latitudes */ |
811 |
|
812 |
/* BSDF angle specification */ |
813 |
typedef struct { |
814 |
char name[64]; /* basis name */ |
815 |
int nangles; /* total number of directions */ |
816 |
struct { |
817 |
float tmin; /* starting theta */ |
818 |
short nphis; /* number of phis (0 term) */ |
819 |
} lat[MAXLATS+1]; /* latitudes */ |
820 |
} ANGLE_BASIS; |
821 |
|
822 |
#define MAXABASES 7 /* limit on defined bases */ |
823 |
|
824 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
825 |
{ |
826 |
"LBNL/Klems Full", 145, |
827 |
{ {-5., 1}, |
828 |
{5., 8}, |
829 |
{15., 16}, |
830 |
{25., 20}, |
831 |
{35., 24}, |
832 |
{45., 24}, |
833 |
{55., 24}, |
834 |
{65., 16}, |
835 |
{75., 12}, |
836 |
{90., 0} } |
837 |
}, { |
838 |
"LBNL/Klems Half", 73, |
839 |
{ {-6.5, 1}, |
840 |
{6.5, 8}, |
841 |
{19.5, 12}, |
842 |
{32.5, 16}, |
843 |
{46.5, 20}, |
844 |
{61.5, 12}, |
845 |
{76.5, 4}, |
846 |
{90., 0} } |
847 |
}, { |
848 |
"LBNL/Klems Quarter", 41, |
849 |
{ {-9., 1}, |
850 |
{9., 8}, |
851 |
{27., 12}, |
852 |
{46., 12}, |
853 |
{66., 8}, |
854 |
{90., 0} } |
855 |
} |
856 |
}; |
857 |
|
858 |
static int nabases = 3; /* current number of defined bases */ |
859 |
|
860 |
#define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6) |
861 |
|
862 |
static int |
863 |
fequal(double a, double b) |
864 |
{ |
865 |
if (b != .0) |
866 |
a = a/b - 1.; |
867 |
return((a <= 1e-6) & (a >= -1e-6)); |
868 |
} |
869 |
|
870 |
/* Returns the name of the given tag */ |
871 |
#ifdef ezxml_name |
872 |
#undef ezxml_name |
873 |
static char * |
874 |
ezxml_name(ezxml_t xml) |
875 |
{ |
876 |
if (xml == NULL) |
877 |
return(NULL); |
878 |
return(xml->name); |
879 |
} |
880 |
#endif |
881 |
|
882 |
/* Returns the given tag's character content or empty string if none */ |
883 |
#ifdef ezxml_txt |
884 |
#undef ezxml_txt |
885 |
static char * |
886 |
ezxml_txt(ezxml_t xml) |
887 |
{ |
888 |
if (xml == NULL) |
889 |
return(""); |
890 |
return(xml->txt); |
891 |
} |
892 |
#endif |
893 |
|
894 |
|
895 |
static int |
896 |
ab_getvec( /* get vector for this angle basis index */ |
897 |
FVECT v, |
898 |
int ndx, |
899 |
void *p |
900 |
) |
901 |
{ |
902 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
903 |
int li; |
904 |
double pol, azi, d; |
905 |
|
906 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
907 |
return(0); |
908 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
909 |
ndx -= ab->lat[li].nphis; |
910 |
pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin); |
911 |
azi = 2.*PI*ndx/ab->lat[li].nphis; |
912 |
v[2] = d = cos(pol); |
913 |
d = sqrt(1. - d*d); /* sin(pol) */ |
914 |
v[0] = cos(azi)*d; |
915 |
v[1] = sin(azi)*d; |
916 |
return(1); |
917 |
} |
918 |
|
919 |
|
920 |
static int |
921 |
ab_getndx( /* get index corresponding to the given vector */ |
922 |
FVECT v, |
923 |
void *p |
924 |
) |
925 |
{ |
926 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
927 |
int li, ndx; |
928 |
double pol, azi, d; |
929 |
|
930 |
if ((v[2] < -1.0) | (v[2] > 1.0)) |
931 |
return(-1); |
932 |
pol = 180.0/PI*acos(v[2]); |
933 |
azi = 180.0/PI*atan2(v[1], v[0]); |
934 |
if (azi < 0.0) azi += 360.0; |
935 |
for (li = 1; ab->lat[li].tmin <= pol; li++) |
936 |
if (!ab->lat[li].nphis) |
937 |
return(-1); |
938 |
--li; |
939 |
ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
940 |
if (ndx >= ab->lat[li].nphis) ndx = 0; |
941 |
while (li--) |
942 |
ndx += ab->lat[li].nphis; |
943 |
return(ndx); |
944 |
} |
945 |
|
946 |
|
947 |
static double |
948 |
ab_getohm( /* get solid angle for this angle basis index */ |
949 |
int ndx, |
950 |
void *p |
951 |
) |
952 |
{ |
953 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
954 |
int li; |
955 |
double theta, theta1; |
956 |
|
957 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
958 |
return(0); |
959 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
960 |
ndx -= ab->lat[li].nphis; |
961 |
theta1 = PI/180. * ab->lat[li+1].tmin; |
962 |
if (ab->lat[li].nphis == 1) { /* special case */ |
963 |
if (ab->lat[li].tmin > FTINY) |
964 |
error(USER, "unsupported BSDF coordinate system"); |
965 |
return(2.*PI*(1. - cos(theta1))); |
966 |
} |
967 |
theta = PI/180. * ab->lat[li].tmin; |
968 |
return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis); |
969 |
} |
970 |
|
971 |
|
972 |
static int |
973 |
ab_getvecR( /* get reverse vector for this angle basis index */ |
974 |
FVECT v, |
975 |
int ndx, |
976 |
void *p |
977 |
) |
978 |
{ |
979 |
if (!ab_getvec(v, ndx, p)) |
980 |
return(0); |
981 |
|
982 |
v[0] = -v[0]; |
983 |
v[1] = -v[1]; |
984 |
v[2] = -v[2]; |
985 |
|
986 |
return(1); |
987 |
} |
988 |
|
989 |
|
990 |
static int |
991 |
ab_getndxR( /* get index corresponding to the reverse vector */ |
992 |
FVECT v, |
993 |
void *p |
994 |
) |
995 |
{ |
996 |
FVECT v2; |
997 |
|
998 |
v2[0] = -v[0]; |
999 |
v2[1] = -v[1]; |
1000 |
v2[2] = -v[2]; |
1001 |
|
1002 |
return ab_getndx(v2, p); |
1003 |
} |
1004 |
|
1005 |
|
1006 |
static void |
1007 |
load_angle_basis( /* load custom BSDF angle basis */ |
1008 |
ezxml_t wab |
1009 |
) |
1010 |
{ |
1011 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
1012 |
ezxml_t wbb; |
1013 |
int i; |
1014 |
|
1015 |
if (!abname || !*abname) |
1016 |
return; |
1017 |
for (i = nabases; i--; ) |
1018 |
if (!strcasecmp(abname, abase_list[i].name)) |
1019 |
return; /* assume it's the same */ |
1020 |
if (nabases >= MAXABASES) |
1021 |
error(INTERNAL, "too many angle bases"); |
1022 |
strcpy(abase_list[nabases].name, abname); |
1023 |
abase_list[nabases].nangles = 0; |
1024 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
1025 |
wbb != NULL; i++, wbb = wbb->next) { |
1026 |
if (i >= MAXLATS) |
1027 |
error(INTERNAL, "too many latitudes in custom basis"); |
1028 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
1029 |
ezxml_child(ezxml_child(wbb, |
1030 |
"ThetaBounds"), "UpperTheta"))); |
1031 |
if (!i) |
1032 |
abase_list[nabases].lat[i].tmin = |
1033 |
-abase_list[nabases].lat[i+1].tmin; |
1034 |
else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
1035 |
"ThetaBounds"), "LowerTheta"))), |
1036 |
abase_list[nabases].lat[i].tmin)) |
1037 |
error(WARNING, "theta values disagree in custom basis"); |
1038 |
abase_list[nabases].nangles += |
1039 |
abase_list[nabases].lat[i].nphis = |
1040 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
1041 |
} |
1042 |
abase_list[nabases++].lat[i].nphis = 0; |
1043 |
} |
1044 |
|
1045 |
|
1046 |
static void |
1047 |
load_geometry( /* load geometric dimensions and description (if any) */ |
1048 |
struct BSDF_data *dp, |
1049 |
ezxml_t wdb |
1050 |
) |
1051 |
{ |
1052 |
ezxml_t geom; |
1053 |
double cfact; |
1054 |
const char *fmt, *mgfstr; |
1055 |
|
1056 |
dp->dim[0] = dp->dim[1] = dp->dim[2] = 0; |
1057 |
dp->mgf = NULL; |
1058 |
if ((geom = ezxml_child(wdb, "Width")) != NULL) |
1059 |
dp->dim[0] = atof(ezxml_txt(geom)) * |
1060 |
to_meters(ezxml_attr(geom, "unit")); |
1061 |
if ((geom = ezxml_child(wdb, "Height")) != NULL) |
1062 |
dp->dim[1] = atof(ezxml_txt(geom)) * |
1063 |
to_meters(ezxml_attr(geom, "unit")); |
1064 |
if ((geom = ezxml_child(wdb, "Thickness")) != NULL) |
1065 |
dp->dim[2] = atof(ezxml_txt(geom)) * |
1066 |
to_meters(ezxml_attr(geom, "unit")); |
1067 |
if ((geom = ezxml_child(wdb, "Geometry")) == NULL || |
1068 |
(mgfstr = ezxml_txt(geom)) == NULL) |
1069 |
return; |
1070 |
if ((fmt = ezxml_attr(geom, "format")) != NULL && |
1071 |
strcasecmp(fmt, "MGF")) { |
1072 |
sprintf(errmsg, "unrecognized geometry format '%s'", fmt); |
1073 |
error(WARNING, errmsg); |
1074 |
return; |
1075 |
} |
1076 |
cfact = to_meters(ezxml_attr(geom, "unit")); |
1077 |
dp->mgf = (char *)malloc(strlen(mgfstr)+32); |
1078 |
if (dp->mgf == NULL) |
1079 |
error(SYSTEM, "out of memory in load_geometry"); |
1080 |
if (cfact < 0.99 || cfact > 1.01) |
1081 |
sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
1082 |
else |
1083 |
strcpy(dp->mgf, mgfstr); |
1084 |
} |
1085 |
|
1086 |
|
1087 |
static void |
1088 |
load_bsdf_data( /* load BSDF distribution for this wavelength */ |
1089 |
struct BSDF_data *dp, |
1090 |
ezxml_t wdb |
1091 |
) |
1092 |
{ |
1093 |
char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
1094 |
char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
1095 |
char *sdata; |
1096 |
int i; |
1097 |
|
1098 |
if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) { |
1099 |
error(WARNING, "missing column/row basis for BSDF"); |
1100 |
return; |
1101 |
} |
1102 |
for (i = nabases; i--; ) |
1103 |
if (!strcasecmp(cbasis, abase_list[i].name)) { |
1104 |
dp->ninc = abase_list[i].nangles; |
1105 |
dp->ib_priv = (void *)&abase_list[i]; |
1106 |
dp->ib_vec = ab_getvecR; |
1107 |
dp->ib_ndx = ab_getndxR; |
1108 |
dp->ib_ohm = ab_getohm; |
1109 |
break; |
1110 |
} |
1111 |
if (i < 0) { |
1112 |
sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis); |
1113 |
error(WARNING, errmsg); |
1114 |
return; |
1115 |
} |
1116 |
for (i = nabases; i--; ) |
1117 |
if (!strcasecmp(rbasis, abase_list[i].name)) { |
1118 |
dp->nout = abase_list[i].nangles; |
1119 |
dp->ob_priv = (void *)&abase_list[i]; |
1120 |
dp->ob_vec = ab_getvec; |
1121 |
dp->ob_ndx = ab_getndx; |
1122 |
dp->ob_ohm = ab_getohm; |
1123 |
break; |
1124 |
} |
1125 |
if (i < 0) { |
1126 |
sprintf(errmsg, "undefined RowAngleBasis '%s'", rbasis); |
1127 |
error(WARNING, errmsg); |
1128 |
return; |
1129 |
} |
1130 |
/* read BSDF data */ |
1131 |
sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData")); |
1132 |
if (!sdata || !*sdata) { |
1133 |
error(WARNING, "missing BSDF ScatteringData"); |
1134 |
return; |
1135 |
} |
1136 |
dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout); |
1137 |
if (dp->bsdf == NULL) |
1138 |
error(SYSTEM, "out of memory in load_bsdf_data"); |
1139 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
1140 |
char *sdnext = fskip(sdata); |
1141 |
if (sdnext == NULL) { |
1142 |
error(WARNING, "bad/missing BSDF ScatteringData"); |
1143 |
free(dp->bsdf); dp->bsdf = NULL; |
1144 |
return; |
1145 |
} |
1146 |
while (*sdnext && isspace(*sdnext)) |
1147 |
sdnext++; |
1148 |
if (*sdnext == ',') sdnext++; |
1149 |
dp->bsdf[i] = atof(sdata); |
1150 |
sdata = sdnext; |
1151 |
} |
1152 |
while (isspace(*sdata)) |
1153 |
sdata++; |
1154 |
if (*sdata) { |
1155 |
sprintf(errmsg, "%d extra characters after BSDF ScatteringData", |
1156 |
(int)strlen(sdata)); |
1157 |
error(WARNING, errmsg); |
1158 |
} |
1159 |
} |
1160 |
|
1161 |
|
1162 |
static int |
1163 |
check_bsdf_data( /* check that BSDF data is sane */ |
1164 |
struct BSDF_data *dp |
1165 |
) |
1166 |
{ |
1167 |
double *omega_iarr, *omega_oarr; |
1168 |
double dom, contrib, hemi_total, full_total; |
1169 |
int nneg; |
1170 |
FVECT v; |
1171 |
int i, o; |
1172 |
|
1173 |
if (dp == NULL || dp->bsdf == NULL) |
1174 |
return(0); |
1175 |
omega_iarr = (double *)calloc(dp->ninc, sizeof(double)); |
1176 |
omega_oarr = (double *)calloc(dp->nout, sizeof(double)); |
1177 |
if ((omega_iarr == NULL) | (omega_oarr == NULL)) |
1178 |
error(SYSTEM, "out of memory in check_bsdf_data"); |
1179 |
/* incoming projected solid angles */ |
1180 |
hemi_total = .0; |
1181 |
for (i = dp->ninc; i--; ) { |
1182 |
dom = getBSDF_incohm(dp,i); |
1183 |
if (dom <= .0) { |
1184 |
error(WARNING, "zero/negative incoming solid angle"); |
1185 |
continue; |
1186 |
} |
1187 |
if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) { |
1188 |
error(WARNING, "illegal incoming BSDF direction"); |
1189 |
free(omega_iarr); free(omega_oarr); |
1190 |
return(0); |
1191 |
} |
1192 |
hemi_total += omega_iarr[i] = dom * -v[2]; |
1193 |
} |
1194 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
1195 |
sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%", |
1196 |
100.*(hemi_total/PI - 1.)); |
1197 |
error(WARNING, errmsg); |
1198 |
} |
1199 |
dom = PI / hemi_total; /* fix normalization */ |
1200 |
for (i = dp->ninc; i--; ) |
1201 |
omega_iarr[i] *= dom; |
1202 |
/* outgoing projected solid angles */ |
1203 |
hemi_total = .0; |
1204 |
for (o = dp->nout; o--; ) { |
1205 |
dom = getBSDF_outohm(dp,o); |
1206 |
if (dom <= .0) { |
1207 |
error(WARNING, "zero/negative outgoing solid angle"); |
1208 |
continue; |
1209 |
} |
1210 |
if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) { |
1211 |
error(WARNING, "illegal outgoing BSDF direction"); |
1212 |
free(omega_iarr); free(omega_oarr); |
1213 |
return(0); |
1214 |
} |
1215 |
hemi_total += omega_oarr[o] = dom * v[2]; |
1216 |
} |
1217 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
1218 |
sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%", |
1219 |
100.*(hemi_total/PI - 1.)); |
1220 |
error(WARNING, errmsg); |
1221 |
} |
1222 |
dom = PI / hemi_total; /* fix normalization */ |
1223 |
for (o = dp->nout; o--; ) |
1224 |
omega_oarr[o] *= dom; |
1225 |
nneg = 0; /* check outgoing totals */ |
1226 |
for (i = 0; i < dp->ninc; i++) { |
1227 |
hemi_total = .0; |
1228 |
for (o = dp->nout; o--; ) { |
1229 |
double f = BSDF_value(dp,i,o); |
1230 |
if (f >= .0) |
1231 |
hemi_total += f*omega_oarr[o]; |
1232 |
else { |
1233 |
nneg += (f < -FTINY); |
1234 |
BSDF_value(dp,i,o) = .0f; |
1235 |
} |
1236 |
} |
1237 |
if (hemi_total > 1.01) { |
1238 |
sprintf(errmsg, |
1239 |
"incoming BSDF direction %d passes %.1f%% of light", |
1240 |
i, 100.*hemi_total); |
1241 |
error(WARNING, errmsg); |
1242 |
} |
1243 |
} |
1244 |
if (nneg) { |
1245 |
sprintf(errmsg, "%d negative BSDF values (ignored)", nneg); |
1246 |
error(WARNING, errmsg); |
1247 |
} |
1248 |
full_total = .0; /* reverse roles and check again */ |
1249 |
for (o = 0; o < dp->nout; o++) { |
1250 |
hemi_total = .0; |
1251 |
for (i = dp->ninc; i--; ) |
1252 |
hemi_total += BSDF_value(dp,i,o) * omega_iarr[i]; |
1253 |
|
1254 |
if (hemi_total > 1.01) { |
1255 |
sprintf(errmsg, |
1256 |
"outgoing BSDF direction %d collects %.1f%% of light", |
1257 |
o, 100.*hemi_total); |
1258 |
error(WARNING, errmsg); |
1259 |
} |
1260 |
full_total += hemi_total*omega_oarr[o]; |
1261 |
} |
1262 |
full_total /= PI; |
1263 |
if (full_total > 1.00001) { |
1264 |
sprintf(errmsg, "BSDF transfers %.4f%% of light", |
1265 |
100.*full_total); |
1266 |
error(WARNING, errmsg); |
1267 |
} |
1268 |
free(omega_iarr); free(omega_oarr); |
1269 |
return(1); |
1270 |
} |
1271 |
|
1272 |
|
1273 |
struct BSDF_data * |
1274 |
load_BSDF( /* load BSDF data from file */ |
1275 |
char *fname |
1276 |
) |
1277 |
{ |
1278 |
char *path; |
1279 |
ezxml_t fl, wtl, wld, wdb; |
1280 |
struct BSDF_data *dp; |
1281 |
|
1282 |
path = getpath(fname, getrlibpath(), R_OK); |
1283 |
if (path == NULL) { |
1284 |
sprintf(errmsg, "cannot find BSDF file \"%s\"", fname); |
1285 |
error(WARNING, errmsg); |
1286 |
return(NULL); |
1287 |
} |
1288 |
fl = ezxml_parse_file(path); |
1289 |
if (fl == NULL) { |
1290 |
sprintf(errmsg, "cannot open BSDF \"%s\"", path); |
1291 |
error(WARNING, errmsg); |
1292 |
return(NULL); |
1293 |
} |
1294 |
if (ezxml_error(fl)[0]) { |
1295 |
sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl)); |
1296 |
error(WARNING, errmsg); |
1297 |
ezxml_free(fl); |
1298 |
return(NULL); |
1299 |
} |
1300 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
1301 |
sprintf(errmsg, |
1302 |
"BSDF \"%s\": top level node not 'WindowElement'", |
1303 |
path); |
1304 |
error(WARNING, errmsg); |
1305 |
ezxml_free(fl); |
1306 |
return(NULL); |
1307 |
} |
1308 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
1309 |
if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl, |
1310 |
"DataDefinition"), "IncidentDataStructure")), |
1311 |
"Columns")) { |
1312 |
sprintf(errmsg, |
1313 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
1314 |
path); |
1315 |
error(WARNING, errmsg); |
1316 |
ezxml_free(fl); |
1317 |
return(NULL); |
1318 |
} |
1319 |
load_angle_basis(ezxml_child(ezxml_child(wtl, |
1320 |
"DataDefinition"), "AngleBasis")); |
1321 |
dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
1322 |
load_geometry(dp, ezxml_child(wtl, "Material")); |
1323 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
1324 |
wld != NULL; wld = wld->next) { |
1325 |
if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")), |
1326 |
"Visible")) |
1327 |
continue; |
1328 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
1329 |
wdb != NULL; wdb = wdb->next) |
1330 |
if (!strcasecmp(ezxml_txt(ezxml_child(wdb, |
1331 |
"WavelengthDataDirection")), |
1332 |
"Transmission Front")) |
1333 |
break; |
1334 |
if (wdb != NULL) { /* load front BTDF */ |
1335 |
load_bsdf_data(dp, wdb); |
1336 |
break; /* ignore the rest */ |
1337 |
} |
1338 |
} |
1339 |
ezxml_free(fl); /* done with XML file */ |
1340 |
if (!check_bsdf_data(dp)) { |
1341 |
sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path); |
1342 |
error(WARNING, errmsg); |
1343 |
free_BSDF(dp); |
1344 |
dp = NULL; |
1345 |
} |
1346 |
return(dp); |
1347 |
} |
1348 |
|
1349 |
|
1350 |
void |
1351 |
free_BSDF( /* free BSDF data structure */ |
1352 |
struct BSDF_data *b |
1353 |
) |
1354 |
{ |
1355 |
if (b == NULL) |
1356 |
return; |
1357 |
if (b->mgf != NULL) |
1358 |
free(b->mgf); |
1359 |
if (b->bsdf != NULL) |
1360 |
free(b->bsdf); |
1361 |
free(b); |
1362 |
} |
1363 |
|
1364 |
|
1365 |
int |
1366 |
r_BSDF_incvec( /* compute random input vector at given location */ |
1367 |
FVECT v, |
1368 |
struct BSDF_data *b, |
1369 |
int i, |
1370 |
double rv, |
1371 |
MAT4 xm |
1372 |
) |
1373 |
{ |
1374 |
FVECT pert; |
1375 |
double rad; |
1376 |
int j; |
1377 |
|
1378 |
if (!getBSDF_incvec(v, b, i)) |
1379 |
return(0); |
1380 |
rad = sqrt(getBSDF_incohm(b, i) / PI); |
1381 |
multisamp(pert, 3, rv); |
1382 |
for (j = 0; j < 3; j++) |
1383 |
v[j] += rad*(2.*pert[j] - 1.); |
1384 |
if (xm != NULL) |
1385 |
multv3(v, v, xm); |
1386 |
return(normalize(v) != 0.0); |
1387 |
} |
1388 |
|
1389 |
|
1390 |
int |
1391 |
r_BSDF_outvec( /* compute random output vector at given location */ |
1392 |
FVECT v, |
1393 |
struct BSDF_data *b, |
1394 |
int o, |
1395 |
double rv, |
1396 |
MAT4 xm |
1397 |
) |
1398 |
{ |
1399 |
FVECT pert; |
1400 |
double rad; |
1401 |
int j; |
1402 |
|
1403 |
if (!getBSDF_outvec(v, b, o)) |
1404 |
return(0); |
1405 |
rad = sqrt(getBSDF_outohm(b, o) / PI); |
1406 |
multisamp(pert, 3, rv); |
1407 |
for (j = 0; j < 3; j++) |
1408 |
v[j] += rad*(2.*pert[j] - 1.); |
1409 |
if (xm != NULL) |
1410 |
multv3(v, v, xm); |
1411 |
return(normalize(v) != 0.0); |
1412 |
} |
1413 |
|
1414 |
|
1415 |
static int |
1416 |
addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
1417 |
char *xfarg[], |
1418 |
FVECT xp, |
1419 |
FVECT yp, |
1420 |
FVECT zp |
1421 |
) |
1422 |
{ |
1423 |
static char bufs[3][16]; |
1424 |
int bn = 0; |
1425 |
char **xfp = xfarg; |
1426 |
double theta; |
1427 |
|
1428 |
if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) { |
1429 |
/* Special case for X' along Z-axis */ |
1430 |
theta = -atan2(yp[0], yp[1]); |
1431 |
*xfp++ = "-ry"; |
1432 |
*xfp++ = xp[2] < 0.0 ? "90" : "-90"; |
1433 |
*xfp++ = "-rz"; |
1434 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1435 |
*xfp++ = bufs[bn++]; |
1436 |
return(xfp - xfarg); |
1437 |
} |
1438 |
theta = atan2(yp[2], zp[2]); |
1439 |
if (!FEQ(theta,0.0)) { |
1440 |
*xfp++ = "-rx"; |
1441 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1442 |
*xfp++ = bufs[bn++]; |
1443 |
} |
1444 |
theta = asin(-xp[2]); |
1445 |
if (!FEQ(theta,0.0)) { |
1446 |
*xfp++ = "-ry"; |
1447 |
sprintf(bufs[bn], " %f", theta*(180./PI)); |
1448 |
*xfp++ = bufs[bn++]; |
1449 |
} |
1450 |
theta = atan2(xp[1], xp[0]); |
1451 |
if (!FEQ(theta,0.0)) { |
1452 |
*xfp++ = "-rz"; |
1453 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1454 |
*xfp++ = bufs[bn++]; |
1455 |
} |
1456 |
*xfp = NULL; |
1457 |
return(xfp - xfarg); |
1458 |
} |
1459 |
|
1460 |
|
1461 |
int |
1462 |
getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */ |
1463 |
MAT4 xm, |
1464 |
FVECT nrm, |
1465 |
UpDir ud, |
1466 |
char *xfbuf |
1467 |
) |
1468 |
{ |
1469 |
char *xfargs[7]; |
1470 |
XF myxf; |
1471 |
FVECT updir, xdest, ydest; |
1472 |
int i; |
1473 |
|
1474 |
updir[0] = updir[1] = updir[2] = 0.; |
1475 |
switch (ud) { |
1476 |
case UDzneg: |
1477 |
updir[2] = -1.; |
1478 |
break; |
1479 |
case UDyneg: |
1480 |
updir[1] = -1.; |
1481 |
break; |
1482 |
case UDxneg: |
1483 |
updir[0] = -1.; |
1484 |
break; |
1485 |
case UDxpos: |
1486 |
updir[0] = 1.; |
1487 |
break; |
1488 |
case UDypos: |
1489 |
updir[1] = 1.; |
1490 |
break; |
1491 |
case UDzpos: |
1492 |
updir[2] = 1.; |
1493 |
break; |
1494 |
case UDunknown: |
1495 |
return(0); |
1496 |
} |
1497 |
fcross(xdest, updir, nrm); |
1498 |
if (normalize(xdest) == 0.0) |
1499 |
return(0); |
1500 |
fcross(ydest, nrm, xdest); |
1501 |
xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
1502 |
copymat4(xm, myxf.xfm); |
1503 |
if (xfbuf == NULL) |
1504 |
return(1); |
1505 |
/* return xf arguments as well */ |
1506 |
for (i = 0; xfargs[i] != NULL; i++) { |
1507 |
*xfbuf++ = ' '; |
1508 |
strcpy(xfbuf, xfargs[i]); |
1509 |
while (*xfbuf) ++xfbuf; |
1510 |
} |
1511 |
return(1); |
1512 |
} |
1513 |
|
1514 |
/*######### END DEPRECATED ROUTINES #######*/ |
1515 |
/*################################################################*/ |