1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf.c,v 2.14 2011/02/11 17:31:25 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 (fp == NULL) |
49 |
return ec; |
50 |
if (!ec) |
51 |
return SDEnone; |
52 |
fputs(SDerrorEnglish[ec], fp); |
53 |
if (SDerrorDetail[0]) { |
54 |
fputs(": ", fp); |
55 |
fputs(SDerrorDetail, fp); |
56 |
} |
57 |
fputc('\n', fp); |
58 |
if (fp != stderr) |
59 |
fflush(fp); |
60 |
return ec; |
61 |
} |
62 |
|
63 |
static double |
64 |
to_meters( /* return factor to convert given unit to meters */ |
65 |
const char *unit |
66 |
) |
67 |
{ |
68 |
if (unit == NULL) return(1.); /* safe assumption? */ |
69 |
if (!strcasecmp(unit, "Meter")) return(1.); |
70 |
if (!strcasecmp(unit, "Foot")) return(.3048); |
71 |
if (!strcasecmp(unit, "Inch")) return(.0254); |
72 |
if (!strcasecmp(unit, "Centimeter")) return(.01); |
73 |
if (!strcasecmp(unit, "Millimeter")) return(.001); |
74 |
sprintf(SDerrorDetail, "Unknown dimensional unit '%s'", unit); |
75 |
return(-1.); |
76 |
} |
77 |
|
78 |
/* Load geometric dimensions and description (if any) */ |
79 |
static SDError |
80 |
SDloadGeometry(SDData *dp, ezxml_t wdb) |
81 |
{ |
82 |
ezxml_t geom; |
83 |
double cfact; |
84 |
const char *fmt, *mgfstr; |
85 |
|
86 |
sprintf(SDerrorDetail, "Negative size in \"%s\"", dp->name); |
87 |
dp->dim[0] = dp->dim[1] = dp->dim[2] = .0; |
88 |
if ((geom = ezxml_child(wdb, "Width")) != NULL) |
89 |
dp->dim[0] = atof(ezxml_txt(geom)) * |
90 |
to_meters(ezxml_attr(geom, "unit")); |
91 |
if ((geom = ezxml_child(wdb, "Height")) != NULL) |
92 |
dp->dim[1] = atof(ezxml_txt(geom)) * |
93 |
to_meters(ezxml_attr(geom, "unit")); |
94 |
if ((geom = ezxml_child(wdb, "Thickness")) != NULL) |
95 |
dp->dim[2] = atof(ezxml_txt(geom)) * |
96 |
to_meters(ezxml_attr(geom, "unit")); |
97 |
if ((dp->dim[0] < .0) | (dp->dim[1] < .0) | (dp->dim[2] < .0)) |
98 |
return SDEdata; |
99 |
if ((geom = ezxml_child(wdb, "Geometry")) == NULL || |
100 |
(mgfstr = ezxml_txt(geom)) == NULL) |
101 |
return SDEnone; |
102 |
if ((fmt = ezxml_attr(geom, "format")) != NULL && |
103 |
strcasecmp(fmt, "MGF")) { |
104 |
sprintf(SDerrorDetail, |
105 |
"Unrecognized geometry format '%s' in \"%s\"", |
106 |
fmt, dp->name); |
107 |
return SDEsupport; |
108 |
} |
109 |
cfact = to_meters(ezxml_attr(geom, "unit")); |
110 |
dp->mgf = (char *)malloc(strlen(mgfstr)+32); |
111 |
if (dp->mgf == NULL) { |
112 |
strcpy(SDerrorDetail, "Out of memory in SDloadGeometry"); |
113 |
return SDEmemory; |
114 |
} |
115 |
if (cfact < 0.99 || cfact > 1.01) |
116 |
sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
117 |
else |
118 |
strcpy(dp->mgf, mgfstr); |
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return SDEnone; |
120 |
} |
121 |
|
122 |
|
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/* Load a BSDF struct from the given file (free first and keep name) */ |
124 |
SDError |
125 |
SDloadFile(SDData *sd, const char *fname) |
126 |
{ |
127 |
SDError lastErr; |
128 |
ezxml_t fl; |
129 |
|
130 |
if ((sd == NULL) | (fname == NULL || !*fname)) |
131 |
return SDEargument; |
132 |
/* free old data, keeping name */ |
133 |
SDfreeBSDF(sd); |
134 |
/* parse XML file */ |
135 |
fl = ezxml_parse_file(fname); |
136 |
if (fl == NULL) { |
137 |
sprintf(SDerrorDetail, "Cannot open BSDF \"%s\"", fname); |
138 |
return SDEfile; |
139 |
} |
140 |
if (ezxml_error(fl)[0]) { |
141 |
sprintf(SDerrorDetail, "BSDF \"%s\" %s", fname, ezxml_error(fl)); |
142 |
ezxml_free(fl); |
143 |
return SDEformat; |
144 |
} |
145 |
/* load geometry if present */ |
146 |
if ((lastErr = SDloadGeometry(sd, fl))) |
147 |
return lastErr; |
148 |
/* try loading variable resolution data */ |
149 |
lastErr = SDloadTre(sd, fl); |
150 |
/* check our result */ |
151 |
switch (lastErr) { |
152 |
case SDEformat: |
153 |
case SDEdata: |
154 |
case SDEsupport: /* possibly we just tried the wrong format */ |
155 |
lastErr = SDloadMtx(sd, fl); |
156 |
break; |
157 |
default: /* variable res. OK else serious error */ |
158 |
break; |
159 |
} |
160 |
/* done with XML file */ |
161 |
ezxml_free(fl); |
162 |
/* return success or failure */ |
163 |
return lastErr; |
164 |
} |
165 |
|
166 |
/* Allocate new spectral distribution function */ |
167 |
SDSpectralDF * |
168 |
SDnewSpectralDF(int nc) |
169 |
{ |
170 |
SDSpectralDF *df; |
171 |
|
172 |
if (nc <= 0) { |
173 |
strcpy(SDerrorDetail, "Zero component spectral DF request"); |
174 |
return NULL; |
175 |
} |
176 |
df = (SDSpectralDF *)malloc(sizeof(SDSpectralDF) + |
177 |
(nc-1)*sizeof(SDComponent)); |
178 |
if (df == NULL) { |
179 |
sprintf(SDerrorDetail, |
180 |
"Cannot allocate %d component spectral DF", nc); |
181 |
return NULL; |
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} |
183 |
df->minProjSA = .0; |
184 |
df->maxHemi = .0; |
185 |
df->ncomp = nc; |
186 |
memset(df->comp, 0, nc*sizeof(SDComponent)); |
187 |
return df; |
188 |
} |
189 |
|
190 |
/* Free cached cumulative distributions for BSDF component */ |
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void |
192 |
SDfreeCumulativeCache(SDSpectralDF *df) |
193 |
{ |
194 |
int n; |
195 |
SDCDst *cdp; |
196 |
|
197 |
if (df == NULL) |
198 |
return; |
199 |
for (n = df->ncomp; n-- > 0; ) |
200 |
while ((cdp = df->comp[n].cdList) != NULL) { |
201 |
df->comp[n].cdList = cdp->next; |
202 |
free(cdp); |
203 |
} |
204 |
} |
205 |
|
206 |
/* Free a spectral distribution function */ |
207 |
void |
208 |
SDfreeSpectralDF(SDSpectralDF *df) |
209 |
{ |
210 |
int n; |
211 |
|
212 |
if (df == NULL) |
213 |
return; |
214 |
SDfreeCumulativeCache(df); |
215 |
for (n = df->ncomp; n-- > 0; ) |
216 |
(*df->comp[n].func->freeSC)(df->comp[n].dist); |
217 |
free(df); |
218 |
} |
219 |
|
220 |
/* Shorten file path to useable BSDF name, removing suffix */ |
221 |
void |
222 |
SDclipName(char res[SDnameLn], const char *fname) |
223 |
{ |
224 |
const char *cp, *dot = NULL; |
225 |
|
226 |
for (cp = fname; *cp; cp++) |
227 |
if (*cp == '.') |
228 |
dot = cp; |
229 |
if ((dot == NULL) | (dot < fname+2)) |
230 |
dot = cp; |
231 |
if (dot - fname >= SDnameLn) |
232 |
fname = dot - SDnameLn + 1; |
233 |
while (fname < dot) |
234 |
*res++ = *fname++; |
235 |
*res = '\0'; |
236 |
} |
237 |
|
238 |
/* Initialize an unused BSDF struct (simply clears to zeroes) */ |
239 |
void |
240 |
SDclearBSDF(SDData *sd) |
241 |
{ |
242 |
if (sd != NULL) |
243 |
memset(sd, 0, sizeof(SDData)); |
244 |
} |
245 |
|
246 |
/* Free data associated with BSDF struct */ |
247 |
void |
248 |
SDfreeBSDF(SDData *sd) |
249 |
{ |
250 |
if (sd == NULL) |
251 |
return; |
252 |
if (sd->mgf != NULL) { |
253 |
free(sd->mgf); |
254 |
sd->mgf = NULL; |
255 |
} |
256 |
if (sd->rf != NULL) { |
257 |
SDfreeSpectralDF(sd->rf); |
258 |
sd->rf = NULL; |
259 |
} |
260 |
if (sd->rb != NULL) { |
261 |
SDfreeSpectralDF(sd->rb); |
262 |
sd->rb = NULL; |
263 |
} |
264 |
if (sd->tf != NULL) { |
265 |
SDfreeSpectralDF(sd->tf); |
266 |
sd->tf = NULL; |
267 |
} |
268 |
sd->rLambFront.cieY = .0; |
269 |
sd->rLambFront.spec.clock = 0; |
270 |
sd->rLambBack.cieY = .0; |
271 |
sd->rLambBack.spec.clock = 0; |
272 |
sd->tLamb.cieY = .0; |
273 |
sd->tLamb.spec.clock = 0; |
274 |
} |
275 |
|
276 |
/* Find writeable BSDF by name, or allocate new cache entry if absent */ |
277 |
SDData * |
278 |
SDgetCache(const char *bname) |
279 |
{ |
280 |
struct SDCache_s *sdl; |
281 |
char sdnam[SDnameLn]; |
282 |
|
283 |
if (bname == NULL) |
284 |
return NULL; |
285 |
|
286 |
SDclipName(sdnam, bname); |
287 |
for (sdl = SDcacheList; sdl != NULL; sdl = sdl->next) |
288 |
if (!strcmp(sdl->bsdf.name, sdnam)) { |
289 |
sdl->refcnt++; |
290 |
return &sdl->bsdf; |
291 |
} |
292 |
|
293 |
sdl = (struct SDCache_s *)calloc(1, sizeof(struct SDCache_s)); |
294 |
if (sdl == NULL) |
295 |
return NULL; |
296 |
|
297 |
strcpy(sdl->bsdf.name, sdnam); |
298 |
sdl->next = SDcacheList; |
299 |
SDcacheList = sdl; |
300 |
|
301 |
sdl->refcnt++; |
302 |
return &sdl->bsdf; |
303 |
} |
304 |
|
305 |
/* Get loaded BSDF from cache (or load and cache it on first call) */ |
306 |
/* Report any problem to stderr and return NULL on failure */ |
307 |
const SDData * |
308 |
SDcacheFile(const char *fname) |
309 |
{ |
310 |
SDData *sd; |
311 |
SDError ec; |
312 |
|
313 |
if (fname == NULL || !*fname) |
314 |
return NULL; |
315 |
SDerrorDetail[0] = '\0'; |
316 |
if ((sd = SDgetCache(fname)) == NULL) { |
317 |
SDreportEnglish(SDEmemory, stderr); |
318 |
return NULL; |
319 |
} |
320 |
if (!SDisLoaded(sd) && (ec = SDloadFile(sd, fname))) { |
321 |
SDreportEnglish(ec, stderr); |
322 |
SDfreeCache(sd); |
323 |
return NULL; |
324 |
} |
325 |
return sd; |
326 |
} |
327 |
|
328 |
/* Free a BSDF from our cache (clear all if NULL) */ |
329 |
void |
330 |
SDfreeCache(const SDData *sd) |
331 |
{ |
332 |
struct SDCache_s *sdl, *sdLast = NULL; |
333 |
|
334 |
if (sd == NULL) { /* free entire list */ |
335 |
while ((sdl = SDcacheList) != NULL) { |
336 |
SDcacheList = sdl->next; |
337 |
SDfreeBSDF(&sdl->bsdf); |
338 |
free(sdl); |
339 |
} |
340 |
return; |
341 |
} |
342 |
for (sdl = SDcacheList; sdl != NULL; sdl = (sdLast=sdl)->next) |
343 |
if (&sdl->bsdf == sd) |
344 |
break; |
345 |
if (sdl == NULL || --sdl->refcnt) |
346 |
return; /* missing or still in use */ |
347 |
/* keep unreferenced data? */ |
348 |
if (SDisLoaded(sd) && SDretainSet) { |
349 |
if (SDretainSet == SDretainAll) |
350 |
return; /* keep everything */ |
351 |
/* else free cumulative data */ |
352 |
SDfreeCumulativeCache(sd->rf); |
353 |
SDfreeCumulativeCache(sd->rb); |
354 |
SDfreeCumulativeCache(sd->tf); |
355 |
return; |
356 |
} |
357 |
/* remove from list and free */ |
358 |
if (sdLast == NULL) |
359 |
SDcacheList = sdl->next; |
360 |
else |
361 |
sdLast->next = sdl->next; |
362 |
SDfreeBSDF(&sdl->bsdf); |
363 |
free(sdl); |
364 |
} |
365 |
|
366 |
/* Sample an individual BSDF component */ |
367 |
SDError |
368 |
SDsampComponent(SDValue *sv, FVECT outVec, const FVECT inVec, |
369 |
double randX, SDComponent *sdc) |
370 |
{ |
371 |
float coef[SDmaxCh]; |
372 |
SDError ec; |
373 |
const SDCDst *cd; |
374 |
double d; |
375 |
int n; |
376 |
/* check arguments */ |
377 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sdc == NULL)) |
378 |
return SDEargument; |
379 |
/* get cumulative distribution */ |
380 |
cd = (*sdc->func->getCDist)(inVec, sdc); |
381 |
if (cd == NULL) |
382 |
return SDEmemory; |
383 |
if (cd->cTotal <= 1e-7) { /* anything to sample? */ |
384 |
sv->spec = c_dfcolor; |
385 |
sv->cieY = .0; |
386 |
memset(outVec, 0, 3*sizeof(double)); |
387 |
return SDEnone; |
388 |
} |
389 |
sv->cieY = cd->cTotal; |
390 |
/* compute sample direction */ |
391 |
ec = (*sdc->func->sampCDist)(outVec, randX, cd); |
392 |
if (ec) |
393 |
return ec; |
394 |
/* get BSDF color */ |
395 |
n = (*sdc->func->getBSDFs)(coef, outVec, inVec, sdc->dist); |
396 |
if (n <= 0) { |
397 |
strcpy(SDerrorDetail, "BSDF sample value error"); |
398 |
return SDEinternal; |
399 |
} |
400 |
sv->spec = sdc->cspec[0]; |
401 |
d = coef[0]; |
402 |
while (--n) { |
403 |
c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]); |
404 |
d += coef[n]; |
405 |
} |
406 |
/* make sure everything is set */ |
407 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
408 |
return SDEnone; |
409 |
} |
410 |
|
411 |
#define MS_MAXDIM 15 |
412 |
|
413 |
/* Convert 1-dimensional random variable to N-dimensional */ |
414 |
void |
415 |
SDmultiSamp(double t[], int n, double randX) |
416 |
{ |
417 |
unsigned nBits; |
418 |
double scale; |
419 |
bitmask_t ndx, coord[MS_MAXDIM]; |
420 |
|
421 |
while (n > MS_MAXDIM) /* punt for higher dimensions */ |
422 |
t[--n] = drand48(); |
423 |
nBits = (8*sizeof(bitmask_t) - 1) / n; |
424 |
ndx = randX * (double)((bitmask_t)1 << (nBits*n)); |
425 |
/* get coordinate on Hilbert curve */ |
426 |
hilbert_i2c(n, nBits, ndx, coord); |
427 |
/* convert back to [0,1) range */ |
428 |
scale = 1. / (double)((bitmask_t)1 << nBits); |
429 |
while (n--) |
430 |
t[n] = scale * ((double)coord[n] + drand48()); |
431 |
} |
432 |
|
433 |
#undef MS_MAXDIM |
434 |
|
435 |
/* Generate diffuse hemispherical sample */ |
436 |
static void |
437 |
SDdiffuseSamp(FVECT outVec, int outFront, double randX) |
438 |
{ |
439 |
/* convert to position on hemisphere */ |
440 |
SDmultiSamp(outVec, 2, randX); |
441 |
SDsquare2disk(outVec, outVec[0], outVec[1]); |
442 |
outVec[2] = 1. - outVec[0]*outVec[0] - outVec[1]*outVec[1]; |
443 |
if (outVec[2] > .0) /* a bit of paranoia */ |
444 |
outVec[2] = sqrt(outVec[2]); |
445 |
if (!outFront) /* going out back? */ |
446 |
outVec[2] = -outVec[2]; |
447 |
} |
448 |
|
449 |
/* Query projected solid angle coverage for non-diffuse BSDF direction */ |
450 |
SDError |
451 |
SDsizeBSDF(double *projSA, const FVECT vec, int qflags, const SDData *sd) |
452 |
{ |
453 |
SDSpectralDF *rdf; |
454 |
SDError ec; |
455 |
int i; |
456 |
/* check arguments */ |
457 |
if ((projSA == NULL) | (vec == NULL) | (sd == NULL)) |
458 |
return SDEargument; |
459 |
/* initialize extrema */ |
460 |
switch (qflags & SDqueryMin+SDqueryMax) { |
461 |
case SDqueryMax: |
462 |
projSA[0] = .0; |
463 |
break; |
464 |
case SDqueryMin+SDqueryMax: |
465 |
projSA[1] = .0; |
466 |
/* fall through */ |
467 |
case SDqueryMin: |
468 |
projSA[0] = 10.; |
469 |
break; |
470 |
case 0: |
471 |
return SDEargument; |
472 |
} |
473 |
if (vec[2] > .0) /* front surface query? */ |
474 |
rdf = sd->rf; |
475 |
else |
476 |
rdf = sd->rb; |
477 |
ec = SDEdata; /* run through components */ |
478 |
for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) { |
479 |
ec = (*rdf->comp[i].func->queryProjSA)(projSA, vec, qflags, |
480 |
rdf->comp[i].dist); |
481 |
if (ec) |
482 |
return ec; |
483 |
} |
484 |
for (i = (sd->tf==NULL) ? 0 : sd->tf->ncomp; i--; ) { |
485 |
ec = (*sd->tf->comp[i].func->queryProjSA)(projSA, vec, qflags, |
486 |
sd->tf->comp[i].dist); |
487 |
if (ec) |
488 |
return ec; |
489 |
} |
490 |
return ec; |
491 |
} |
492 |
|
493 |
/* Return BSDF for the given incident and scattered ray vectors */ |
494 |
SDError |
495 |
SDevalBSDF(SDValue *sv, const FVECT outVec, const FVECT inVec, const SDData *sd) |
496 |
{ |
497 |
int inFront, outFront; |
498 |
SDSpectralDF *sdf; |
499 |
float coef[SDmaxCh]; |
500 |
int nch, i; |
501 |
/* check arguments */ |
502 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL)) |
503 |
return SDEargument; |
504 |
/* whose side are we on? */ |
505 |
inFront = (inVec[2] > .0); |
506 |
outFront = (outVec[2] > .0); |
507 |
/* start with diffuse portion */ |
508 |
if (inFront & outFront) { |
509 |
*sv = sd->rLambFront; |
510 |
sdf = sd->rf; |
511 |
} else if (!(inFront | outFront)) { |
512 |
*sv = sd->rLambBack; |
513 |
sdf = sd->rb; |
514 |
} else /* inFront ^ outFront */ { |
515 |
*sv = sd->tLamb; |
516 |
sdf = sd->tf; |
517 |
} |
518 |
sv->cieY *= 1./M_PI; |
519 |
/* add non-diffuse components */ |
520 |
i = (sdf != NULL) ? sdf->ncomp : 0; |
521 |
while (i-- > 0) { |
522 |
nch = (*sdf->comp[i].func->getBSDFs)(coef, outVec, inVec, |
523 |
sdf->comp[i].dist); |
524 |
while (nch-- > 0) { |
525 |
c_cmix(&sv->spec, sv->cieY, &sv->spec, |
526 |
coef[nch], &sdf->comp[i].cspec[nch]); |
527 |
sv->cieY += coef[nch]; |
528 |
} |
529 |
} |
530 |
/* make sure everything is set */ |
531 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
532 |
return SDEnone; |
533 |
} |
534 |
|
535 |
/* Compute directional hemispherical scattering at this incident angle */ |
536 |
double |
537 |
SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd) |
538 |
{ |
539 |
double hsum; |
540 |
SDSpectralDF *rdf; |
541 |
const SDCDst *cd; |
542 |
int i; |
543 |
/* check arguments */ |
544 |
if ((inVec == NULL) | (sd == NULL)) |
545 |
return .0; |
546 |
/* gather diffuse components */ |
547 |
if (inVec[2] > .0) { |
548 |
hsum = sd->rLambFront.cieY; |
549 |
rdf = sd->rf; |
550 |
} else /* !inFront */ { |
551 |
hsum = sd->rLambBack.cieY; |
552 |
rdf = sd->rb; |
553 |
} |
554 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
555 |
hsum = .0; |
556 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
557 |
hsum += sd->tLamb.cieY; |
558 |
/* gather non-diffuse components */ |
559 |
i = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR && |
560 |
rdf != NULL) ? rdf->ncomp : 0; |
561 |
while (i-- > 0) { /* non-diffuse reflection */ |
562 |
cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
563 |
if (cd != NULL) |
564 |
hsum += cd->cTotal; |
565 |
} |
566 |
i = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT && |
567 |
sd->tf != NULL) ? sd->tf->ncomp : 0; |
568 |
while (i-- > 0) { /* non-diffuse transmission */ |
569 |
cd = (*sd->tf->comp[i].func->getCDist)(inVec, &sd->tf->comp[i]); |
570 |
if (cd != NULL) |
571 |
hsum += cd->cTotal; |
572 |
} |
573 |
return hsum; |
574 |
} |
575 |
|
576 |
/* Sample BSDF direction based on the given random variable */ |
577 |
SDError |
578 |
SDsampBSDF(SDValue *sv, FVECT outVec, const FVECT inVec, |
579 |
double randX, int sflags, const SDData *sd) |
580 |
{ |
581 |
SDError ec; |
582 |
int inFront; |
583 |
SDSpectralDF *rdf; |
584 |
double rdiff; |
585 |
float coef[SDmaxCh]; |
586 |
int i, j, n, nr; |
587 |
SDComponent *sdc; |
588 |
const SDCDst **cdarr = NULL; |
589 |
/* check arguments */ |
590 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL) | |
591 |
(randX < .0) | (randX >= 1.)) |
592 |
return SDEargument; |
593 |
/* whose side are we on? */ |
594 |
inFront = (inVec[2] > .0); |
595 |
/* remember diffuse portions */ |
596 |
if (inFront) { |
597 |
*sv = sd->rLambFront; |
598 |
rdf = sd->rf; |
599 |
} else /* !inFront */ { |
600 |
*sv = sd->rLambBack; |
601 |
rdf = sd->rb; |
602 |
} |
603 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
604 |
sv->cieY = .0; |
605 |
rdiff = sv->cieY; |
606 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
607 |
sv->cieY += sd->tLamb.cieY; |
608 |
/* gather non-diffuse components */ |
609 |
i = nr = ((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR && |
610 |
rdf != NULL) ? rdf->ncomp : 0; |
611 |
j = ((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT && |
612 |
sd->tf != NULL) ? sd->tf->ncomp : 0; |
613 |
n = i + j; |
614 |
if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL) |
615 |
return SDEmemory; |
616 |
while (j-- > 0) { /* non-diffuse transmission */ |
617 |
cdarr[i+j] = (*sd->tf->comp[j].func->getCDist)(inVec, &sd->tf->comp[j]); |
618 |
if (cdarr[i+j] == NULL) { |
619 |
free(cdarr); |
620 |
return SDEmemory; |
621 |
} |
622 |
sv->cieY += cdarr[i+j]->cTotal; |
623 |
} |
624 |
while (i-- > 0) { /* non-diffuse reflection */ |
625 |
cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
626 |
if (cdarr[i] == NULL) { |
627 |
free(cdarr); |
628 |
return SDEmemory; |
629 |
} |
630 |
sv->cieY += cdarr[i]->cTotal; |
631 |
} |
632 |
if (sv->cieY <= 1e-7) { /* anything to sample? */ |
633 |
sv->cieY = .0; |
634 |
memset(outVec, 0, 3*sizeof(double)); |
635 |
return SDEnone; |
636 |
} |
637 |
/* scale random variable */ |
638 |
randX *= sv->cieY; |
639 |
/* diffuse reflection? */ |
640 |
if (randX < rdiff) { |
641 |
SDdiffuseSamp(outVec, inFront, randX/rdiff); |
642 |
goto done; |
643 |
} |
644 |
randX -= rdiff; |
645 |
/* diffuse transmission? */ |
646 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) { |
647 |
if (randX < sd->tLamb.cieY) { |
648 |
sv->spec = sd->tLamb.spec; |
649 |
SDdiffuseSamp(outVec, !inFront, randX/sd->tLamb.cieY); |
650 |
goto done; |
651 |
} |
652 |
randX -= sd->tLamb.cieY; |
653 |
} |
654 |
/* else one of cumulative dist. */ |
655 |
for (i = 0; i < n && randX < cdarr[i]->cTotal; i++) |
656 |
randX -= cdarr[i]->cTotal; |
657 |
if (i >= n) |
658 |
return SDEinternal; |
659 |
/* compute sample direction */ |
660 |
sdc = (i < nr) ? &rdf->comp[i] : &sd->tf->comp[i-nr]; |
661 |
ec = (*sdc->func->sampCDist)(outVec, randX/cdarr[i]->cTotal, cdarr[i]); |
662 |
if (ec) |
663 |
return ec; |
664 |
/* compute color */ |
665 |
j = (*sdc->func->getBSDFs)(coef, outVec, inVec, sdc->dist); |
666 |
if (j <= 0) { |
667 |
sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error", |
668 |
sd->name); |
669 |
return SDEinternal; |
670 |
} |
671 |
sv->spec = sdc->cspec[0]; |
672 |
rdiff = coef[0]; |
673 |
while (--j) { |
674 |
c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]); |
675 |
rdiff += coef[j]; |
676 |
} |
677 |
done: |
678 |
if (cdarr != NULL) |
679 |
free(cdarr); |
680 |
/* make sure everything is set */ |
681 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
682 |
return SDEnone; |
683 |
} |
684 |
|
685 |
/* Compute World->BSDF transform from surface normal and up (Y) vector */ |
686 |
SDError |
687 |
SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec) |
688 |
{ |
689 |
if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL)) |
690 |
return SDEargument; |
691 |
VCOPY(vMtx[2], sNrm); |
692 |
if (normalize(vMtx[2]) == .0) |
693 |
return SDEargument; |
694 |
fcross(vMtx[0], uVec, vMtx[2]); |
695 |
if (normalize(vMtx[0]) == .0) |
696 |
return SDEargument; |
697 |
fcross(vMtx[1], vMtx[2], vMtx[0]); |
698 |
return SDEnone; |
699 |
} |
700 |
|
701 |
/* Compute inverse transform */ |
702 |
SDError |
703 |
SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]) |
704 |
{ |
705 |
RREAL mTmp[3][3]; |
706 |
double d; |
707 |
|
708 |
if ((iMtx == NULL) | (vMtx == NULL)) |
709 |
return SDEargument; |
710 |
/* compute determinant */ |
711 |
mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2]; |
712 |
mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1]; |
713 |
mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2]; |
714 |
d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2]; |
715 |
if (d == .0) { |
716 |
strcpy(SDerrorDetail, "Zero determinant in matrix inversion"); |
717 |
return SDEargument; |
718 |
} |
719 |
d = 1./d; /* invert matrix */ |
720 |
mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d; |
721 |
mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]); |
722 |
mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]); |
723 |
mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]); |
724 |
mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]); |
725 |
mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]); |
726 |
mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]); |
727 |
memcpy(iMtx, mTmp, sizeof(mTmp)); |
728 |
return SDEnone; |
729 |
} |
730 |
|
731 |
/* Transform and normalize direction (column) vector */ |
732 |
SDError |
733 |
SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec) |
734 |
{ |
735 |
FVECT vTmp; |
736 |
|
737 |
if ((resVec == NULL) | (inpVec == NULL)) |
738 |
return SDEargument; |
739 |
if (vMtx == NULL) { /* assume they just want to normalize */ |
740 |
if (resVec != inpVec) |
741 |
VCOPY(resVec, inpVec); |
742 |
return (normalize(resVec) > .0) ? SDEnone : SDEargument; |
743 |
} |
744 |
vTmp[0] = DOT(vMtx[0], inpVec); |
745 |
vTmp[1] = DOT(vMtx[1], inpVec); |
746 |
vTmp[2] = DOT(vMtx[2], inpVec); |
747 |
if (normalize(vTmp) == .0) |
748 |
return SDEargument; |
749 |
VCOPY(resVec, vTmp); |
750 |
return SDEnone; |
751 |
} |
752 |
|
753 |
/*################################################################*/ |
754 |
/*######### DEPRECATED ROUTINES AWAITING PERMANENT REMOVAL #######*/ |
755 |
|
756 |
/* |
757 |
* Routines for handling BSDF data |
758 |
*/ |
759 |
|
760 |
#include "standard.h" |
761 |
#include "paths.h" |
762 |
#include <ctype.h> |
763 |
|
764 |
#define MAXLATS 46 /* maximum number of latitudes */ |
765 |
|
766 |
/* BSDF angle specification */ |
767 |
typedef struct { |
768 |
char name[64]; /* basis name */ |
769 |
int nangles; /* total number of directions */ |
770 |
struct { |
771 |
float tmin; /* starting theta */ |
772 |
short nphis; /* number of phis (0 term) */ |
773 |
} lat[MAXLATS+1]; /* latitudes */ |
774 |
} ANGLE_BASIS; |
775 |
|
776 |
#define MAXABASES 7 /* limit on defined bases */ |
777 |
|
778 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
779 |
{ |
780 |
"LBNL/Klems Full", 145, |
781 |
{ {-5., 1}, |
782 |
{5., 8}, |
783 |
{15., 16}, |
784 |
{25., 20}, |
785 |
{35., 24}, |
786 |
{45., 24}, |
787 |
{55., 24}, |
788 |
{65., 16}, |
789 |
{75., 12}, |
790 |
{90., 0} } |
791 |
}, { |
792 |
"LBNL/Klems Half", 73, |
793 |
{ {-6.5, 1}, |
794 |
{6.5, 8}, |
795 |
{19.5, 12}, |
796 |
{32.5, 16}, |
797 |
{46.5, 20}, |
798 |
{61.5, 12}, |
799 |
{76.5, 4}, |
800 |
{90., 0} } |
801 |
}, { |
802 |
"LBNL/Klems Quarter", 41, |
803 |
{ {-9., 1}, |
804 |
{9., 8}, |
805 |
{27., 12}, |
806 |
{46., 12}, |
807 |
{66., 8}, |
808 |
{90., 0} } |
809 |
} |
810 |
}; |
811 |
|
812 |
static int nabases = 3; /* current number of defined bases */ |
813 |
|
814 |
#define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6) |
815 |
|
816 |
static int |
817 |
fequal(double a, double b) |
818 |
{ |
819 |
if (b != .0) |
820 |
a = a/b - 1.; |
821 |
return((a <= 1e-6) & (a >= -1e-6)); |
822 |
} |
823 |
|
824 |
/* Returns the name of the given tag */ |
825 |
#ifdef ezxml_name |
826 |
#undef ezxml_name |
827 |
static char * |
828 |
ezxml_name(ezxml_t xml) |
829 |
{ |
830 |
if (xml == NULL) |
831 |
return(NULL); |
832 |
return(xml->name); |
833 |
} |
834 |
#endif |
835 |
|
836 |
/* Returns the given tag's character content or empty string if none */ |
837 |
#ifdef ezxml_txt |
838 |
#undef ezxml_txt |
839 |
static char * |
840 |
ezxml_txt(ezxml_t xml) |
841 |
{ |
842 |
if (xml == NULL) |
843 |
return(""); |
844 |
return(xml->txt); |
845 |
} |
846 |
#endif |
847 |
|
848 |
|
849 |
static int |
850 |
ab_getvec( /* get vector for this angle basis index */ |
851 |
FVECT v, |
852 |
int ndx, |
853 |
void *p |
854 |
) |
855 |
{ |
856 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
857 |
int li; |
858 |
double pol, azi, d; |
859 |
|
860 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
861 |
return(0); |
862 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
863 |
ndx -= ab->lat[li].nphis; |
864 |
pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin); |
865 |
azi = 2.*PI*ndx/ab->lat[li].nphis; |
866 |
v[2] = d = cos(pol); |
867 |
d = sqrt(1. - d*d); /* sin(pol) */ |
868 |
v[0] = cos(azi)*d; |
869 |
v[1] = sin(azi)*d; |
870 |
return(1); |
871 |
} |
872 |
|
873 |
|
874 |
static int |
875 |
ab_getndx( /* get index corresponding to the given vector */ |
876 |
FVECT v, |
877 |
void *p |
878 |
) |
879 |
{ |
880 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
881 |
int li, ndx; |
882 |
double pol, azi, d; |
883 |
|
884 |
if ((v[2] < -1.0) | (v[2] > 1.0)) |
885 |
return(-1); |
886 |
pol = 180.0/PI*acos(v[2]); |
887 |
azi = 180.0/PI*atan2(v[1], v[0]); |
888 |
if (azi < 0.0) azi += 360.0; |
889 |
for (li = 1; ab->lat[li].tmin <= pol; li++) |
890 |
if (!ab->lat[li].nphis) |
891 |
return(-1); |
892 |
--li; |
893 |
ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
894 |
if (ndx >= ab->lat[li].nphis) ndx = 0; |
895 |
while (li--) |
896 |
ndx += ab->lat[li].nphis; |
897 |
return(ndx); |
898 |
} |
899 |
|
900 |
|
901 |
static double |
902 |
ab_getohm( /* get solid angle for this angle basis index */ |
903 |
int ndx, |
904 |
void *p |
905 |
) |
906 |
{ |
907 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
908 |
int li; |
909 |
double theta, theta1; |
910 |
|
911 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
912 |
return(0); |
913 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
914 |
ndx -= ab->lat[li].nphis; |
915 |
theta1 = PI/180. * ab->lat[li+1].tmin; |
916 |
if (ab->lat[li].nphis == 1) { /* special case */ |
917 |
if (ab->lat[li].tmin > FTINY) |
918 |
error(USER, "unsupported BSDF coordinate system"); |
919 |
return(2.*PI*(1. - cos(theta1))); |
920 |
} |
921 |
theta = PI/180. * ab->lat[li].tmin; |
922 |
return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis); |
923 |
} |
924 |
|
925 |
|
926 |
static int |
927 |
ab_getvecR( /* get reverse vector for this angle basis index */ |
928 |
FVECT v, |
929 |
int ndx, |
930 |
void *p |
931 |
) |
932 |
{ |
933 |
if (!ab_getvec(v, ndx, p)) |
934 |
return(0); |
935 |
|
936 |
v[0] = -v[0]; |
937 |
v[1] = -v[1]; |
938 |
v[2] = -v[2]; |
939 |
|
940 |
return(1); |
941 |
} |
942 |
|
943 |
|
944 |
static int |
945 |
ab_getndxR( /* get index corresponding to the reverse vector */ |
946 |
FVECT v, |
947 |
void *p |
948 |
) |
949 |
{ |
950 |
FVECT v2; |
951 |
|
952 |
v2[0] = -v[0]; |
953 |
v2[1] = -v[1]; |
954 |
v2[2] = -v[2]; |
955 |
|
956 |
return ab_getndx(v2, p); |
957 |
} |
958 |
|
959 |
|
960 |
static void |
961 |
load_angle_basis( /* load custom BSDF angle basis */ |
962 |
ezxml_t wab |
963 |
) |
964 |
{ |
965 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
966 |
ezxml_t wbb; |
967 |
int i; |
968 |
|
969 |
if (!abname || !*abname) |
970 |
return; |
971 |
for (i = nabases; i--; ) |
972 |
if (!strcasecmp(abname, abase_list[i].name)) |
973 |
return; /* assume it's the same */ |
974 |
if (nabases >= MAXABASES) |
975 |
error(INTERNAL, "too many angle bases"); |
976 |
strcpy(abase_list[nabases].name, abname); |
977 |
abase_list[nabases].nangles = 0; |
978 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
979 |
wbb != NULL; i++, wbb = wbb->next) { |
980 |
if (i >= MAXLATS) |
981 |
error(INTERNAL, "too many latitudes in custom basis"); |
982 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
983 |
ezxml_child(ezxml_child(wbb, |
984 |
"ThetaBounds"), "UpperTheta"))); |
985 |
if (!i) |
986 |
abase_list[nabases].lat[i].tmin = |
987 |
-abase_list[nabases].lat[i+1].tmin; |
988 |
else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
989 |
"ThetaBounds"), "LowerTheta"))), |
990 |
abase_list[nabases].lat[i].tmin)) |
991 |
error(WARNING, "theta values disagree in custom basis"); |
992 |
abase_list[nabases].nangles += |
993 |
abase_list[nabases].lat[i].nphis = |
994 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
995 |
} |
996 |
abase_list[nabases++].lat[i].nphis = 0; |
997 |
} |
998 |
|
999 |
|
1000 |
static void |
1001 |
load_geometry( /* load geometric dimensions and description (if any) */ |
1002 |
struct BSDF_data *dp, |
1003 |
ezxml_t wdb |
1004 |
) |
1005 |
{ |
1006 |
ezxml_t geom; |
1007 |
double cfact; |
1008 |
const char *fmt, *mgfstr; |
1009 |
|
1010 |
dp->dim[0] = dp->dim[1] = dp->dim[2] = 0; |
1011 |
dp->mgf = NULL; |
1012 |
if ((geom = ezxml_child(wdb, "Width")) != NULL) |
1013 |
dp->dim[0] = atof(ezxml_txt(geom)) * |
1014 |
to_meters(ezxml_attr(geom, "unit")); |
1015 |
if ((geom = ezxml_child(wdb, "Height")) != NULL) |
1016 |
dp->dim[1] = atof(ezxml_txt(geom)) * |
1017 |
to_meters(ezxml_attr(geom, "unit")); |
1018 |
if ((geom = ezxml_child(wdb, "Thickness")) != NULL) |
1019 |
dp->dim[2] = atof(ezxml_txt(geom)) * |
1020 |
to_meters(ezxml_attr(geom, "unit")); |
1021 |
if ((geom = ezxml_child(wdb, "Geometry")) == NULL || |
1022 |
(mgfstr = ezxml_txt(geom)) == NULL) |
1023 |
return; |
1024 |
if ((fmt = ezxml_attr(geom, "format")) != NULL && |
1025 |
strcasecmp(fmt, "MGF")) { |
1026 |
sprintf(errmsg, "unrecognized geometry format '%s'", fmt); |
1027 |
error(WARNING, errmsg); |
1028 |
return; |
1029 |
} |
1030 |
cfact = to_meters(ezxml_attr(geom, "unit")); |
1031 |
dp->mgf = (char *)malloc(strlen(mgfstr)+32); |
1032 |
if (dp->mgf == NULL) |
1033 |
error(SYSTEM, "out of memory in load_geometry"); |
1034 |
if (cfact < 0.99 || cfact > 1.01) |
1035 |
sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
1036 |
else |
1037 |
strcpy(dp->mgf, mgfstr); |
1038 |
} |
1039 |
|
1040 |
|
1041 |
static void |
1042 |
load_bsdf_data( /* load BSDF distribution for this wavelength */ |
1043 |
struct BSDF_data *dp, |
1044 |
ezxml_t wdb |
1045 |
) |
1046 |
{ |
1047 |
char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
1048 |
char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
1049 |
char *sdata; |
1050 |
int i; |
1051 |
|
1052 |
if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) { |
1053 |
error(WARNING, "missing column/row basis for BSDF"); |
1054 |
return; |
1055 |
} |
1056 |
for (i = nabases; i--; ) |
1057 |
if (!strcasecmp(cbasis, abase_list[i].name)) { |
1058 |
dp->ninc = abase_list[i].nangles; |
1059 |
dp->ib_priv = (void *)&abase_list[i]; |
1060 |
dp->ib_vec = ab_getvecR; |
1061 |
dp->ib_ndx = ab_getndxR; |
1062 |
dp->ib_ohm = ab_getohm; |
1063 |
break; |
1064 |
} |
1065 |
if (i < 0) { |
1066 |
sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis); |
1067 |
error(WARNING, errmsg); |
1068 |
return; |
1069 |
} |
1070 |
for (i = nabases; i--; ) |
1071 |
if (!strcasecmp(rbasis, abase_list[i].name)) { |
1072 |
dp->nout = abase_list[i].nangles; |
1073 |
dp->ob_priv = (void *)&abase_list[i]; |
1074 |
dp->ob_vec = ab_getvec; |
1075 |
dp->ob_ndx = ab_getndx; |
1076 |
dp->ob_ohm = ab_getohm; |
1077 |
break; |
1078 |
} |
1079 |
if (i < 0) { |
1080 |
sprintf(errmsg, "undefined RowAngleBasis '%s'", cbasis); |
1081 |
error(WARNING, errmsg); |
1082 |
return; |
1083 |
} |
1084 |
/* read BSDF data */ |
1085 |
sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData")); |
1086 |
if (!sdata || !*sdata) { |
1087 |
error(WARNING, "missing BSDF ScatteringData"); |
1088 |
return; |
1089 |
} |
1090 |
dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout); |
1091 |
if (dp->bsdf == NULL) |
1092 |
error(SYSTEM, "out of memory in load_bsdf_data"); |
1093 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
1094 |
char *sdnext = fskip(sdata); |
1095 |
if (sdnext == NULL) { |
1096 |
error(WARNING, "bad/missing BSDF ScatteringData"); |
1097 |
free(dp->bsdf); dp->bsdf = NULL; |
1098 |
return; |
1099 |
} |
1100 |
while (*sdnext && isspace(*sdnext)) |
1101 |
sdnext++; |
1102 |
if (*sdnext == ',') sdnext++; |
1103 |
dp->bsdf[i] = atof(sdata); |
1104 |
sdata = sdnext; |
1105 |
} |
1106 |
while (isspace(*sdata)) |
1107 |
sdata++; |
1108 |
if (*sdata) { |
1109 |
sprintf(errmsg, "%d extra characters after BSDF ScatteringData", |
1110 |
(int)strlen(sdata)); |
1111 |
error(WARNING, errmsg); |
1112 |
} |
1113 |
} |
1114 |
|
1115 |
|
1116 |
static int |
1117 |
check_bsdf_data( /* check that BSDF data is sane */ |
1118 |
struct BSDF_data *dp |
1119 |
) |
1120 |
{ |
1121 |
double *omega_iarr, *omega_oarr; |
1122 |
double dom, contrib, hemi_total, full_total; |
1123 |
int nneg; |
1124 |
FVECT v; |
1125 |
int i, o; |
1126 |
|
1127 |
if (dp == NULL || dp->bsdf == NULL) |
1128 |
return(0); |
1129 |
omega_iarr = (double *)calloc(dp->ninc, sizeof(double)); |
1130 |
omega_oarr = (double *)calloc(dp->nout, sizeof(double)); |
1131 |
if ((omega_iarr == NULL) | (omega_oarr == NULL)) |
1132 |
error(SYSTEM, "out of memory in check_bsdf_data"); |
1133 |
/* incoming projected solid angles */ |
1134 |
hemi_total = .0; |
1135 |
for (i = dp->ninc; i--; ) { |
1136 |
dom = getBSDF_incohm(dp,i); |
1137 |
if (dom <= .0) { |
1138 |
error(WARNING, "zero/negative incoming solid angle"); |
1139 |
continue; |
1140 |
} |
1141 |
if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) { |
1142 |
error(WARNING, "illegal incoming BSDF direction"); |
1143 |
free(omega_iarr); free(omega_oarr); |
1144 |
return(0); |
1145 |
} |
1146 |
hemi_total += omega_iarr[i] = dom * -v[2]; |
1147 |
} |
1148 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
1149 |
sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%", |
1150 |
100.*(hemi_total/PI - 1.)); |
1151 |
error(WARNING, errmsg); |
1152 |
} |
1153 |
dom = PI / hemi_total; /* fix normalization */ |
1154 |
for (i = dp->ninc; i--; ) |
1155 |
omega_iarr[i] *= dom; |
1156 |
/* outgoing projected solid angles */ |
1157 |
hemi_total = .0; |
1158 |
for (o = dp->nout; o--; ) { |
1159 |
dom = getBSDF_outohm(dp,o); |
1160 |
if (dom <= .0) { |
1161 |
error(WARNING, "zero/negative outgoing solid angle"); |
1162 |
continue; |
1163 |
} |
1164 |
if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) { |
1165 |
error(WARNING, "illegal outgoing BSDF direction"); |
1166 |
free(omega_iarr); free(omega_oarr); |
1167 |
return(0); |
1168 |
} |
1169 |
hemi_total += omega_oarr[o] = dom * v[2]; |
1170 |
} |
1171 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
1172 |
sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%", |
1173 |
100.*(hemi_total/PI - 1.)); |
1174 |
error(WARNING, errmsg); |
1175 |
} |
1176 |
dom = PI / hemi_total; /* fix normalization */ |
1177 |
for (o = dp->nout; o--; ) |
1178 |
omega_oarr[o] *= dom; |
1179 |
nneg = 0; /* check outgoing totals */ |
1180 |
for (i = 0; i < dp->ninc; i++) { |
1181 |
hemi_total = .0; |
1182 |
for (o = dp->nout; o--; ) { |
1183 |
double f = BSDF_value(dp,i,o); |
1184 |
if (f >= .0) |
1185 |
hemi_total += f*omega_oarr[o]; |
1186 |
else { |
1187 |
nneg += (f < -FTINY); |
1188 |
BSDF_value(dp,i,o) = .0f; |
1189 |
} |
1190 |
} |
1191 |
if (hemi_total > 1.01) { |
1192 |
sprintf(errmsg, |
1193 |
"incoming BSDF direction %d passes %.1f%% of light", |
1194 |
i, 100.*hemi_total); |
1195 |
error(WARNING, errmsg); |
1196 |
} |
1197 |
} |
1198 |
if (nneg) { |
1199 |
sprintf(errmsg, "%d negative BSDF values (ignored)", nneg); |
1200 |
error(WARNING, errmsg); |
1201 |
} |
1202 |
full_total = .0; /* reverse roles and check again */ |
1203 |
for (o = 0; o < dp->nout; o++) { |
1204 |
hemi_total = .0; |
1205 |
for (i = dp->ninc; i--; ) |
1206 |
hemi_total += BSDF_value(dp,i,o) * omega_iarr[i]; |
1207 |
|
1208 |
if (hemi_total > 1.01) { |
1209 |
sprintf(errmsg, |
1210 |
"outgoing BSDF direction %d collects %.1f%% of light", |
1211 |
o, 100.*hemi_total); |
1212 |
error(WARNING, errmsg); |
1213 |
} |
1214 |
full_total += hemi_total*omega_oarr[o]; |
1215 |
} |
1216 |
full_total /= PI; |
1217 |
if (full_total > 1.00001) { |
1218 |
sprintf(errmsg, "BSDF transfers %.4f%% of light", |
1219 |
100.*full_total); |
1220 |
error(WARNING, errmsg); |
1221 |
} |
1222 |
free(omega_iarr); free(omega_oarr); |
1223 |
return(1); |
1224 |
} |
1225 |
|
1226 |
|
1227 |
struct BSDF_data * |
1228 |
load_BSDF( /* load BSDF data from file */ |
1229 |
char *fname |
1230 |
) |
1231 |
{ |
1232 |
char *path; |
1233 |
ezxml_t fl, wtl, wld, wdb; |
1234 |
struct BSDF_data *dp; |
1235 |
|
1236 |
path = getpath(fname, getrlibpath(), R_OK); |
1237 |
if (path == NULL) { |
1238 |
sprintf(errmsg, "cannot find BSDF file \"%s\"", fname); |
1239 |
error(WARNING, errmsg); |
1240 |
return(NULL); |
1241 |
} |
1242 |
fl = ezxml_parse_file(path); |
1243 |
if (fl == NULL) { |
1244 |
sprintf(errmsg, "cannot open BSDF \"%s\"", path); |
1245 |
error(WARNING, errmsg); |
1246 |
return(NULL); |
1247 |
} |
1248 |
if (ezxml_error(fl)[0]) { |
1249 |
sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl)); |
1250 |
error(WARNING, errmsg); |
1251 |
ezxml_free(fl); |
1252 |
return(NULL); |
1253 |
} |
1254 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
1255 |
sprintf(errmsg, |
1256 |
"BSDF \"%s\": top level node not 'WindowElement'", |
1257 |
path); |
1258 |
error(WARNING, errmsg); |
1259 |
ezxml_free(fl); |
1260 |
return(NULL); |
1261 |
} |
1262 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
1263 |
if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl, |
1264 |
"DataDefinition"), "IncidentDataStructure")), |
1265 |
"Columns")) { |
1266 |
sprintf(errmsg, |
1267 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
1268 |
path); |
1269 |
error(WARNING, errmsg); |
1270 |
ezxml_free(fl); |
1271 |
return(NULL); |
1272 |
} |
1273 |
load_angle_basis(ezxml_child(ezxml_child(wtl, |
1274 |
"DataDefinition"), "AngleBasis")); |
1275 |
dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
1276 |
load_geometry(dp, ezxml_child(wtl, "Material")); |
1277 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
1278 |
wld != NULL; wld = wld->next) { |
1279 |
if (strcasecmp(ezxml_txt(ezxml_child(wld,"Wavelength")), |
1280 |
"Visible")) |
1281 |
continue; |
1282 |
for (wdb = ezxml_child(wld, "WavelengthDataBlock"); |
1283 |
wdb != NULL; wdb = wdb->next) |
1284 |
if (!strcasecmp(ezxml_txt(ezxml_child(wdb, |
1285 |
"WavelengthDataDirection")), |
1286 |
"Transmission Front")) |
1287 |
break; |
1288 |
if (wdb != NULL) { /* load front BTDF */ |
1289 |
load_bsdf_data(dp, wdb); |
1290 |
break; /* ignore the rest */ |
1291 |
} |
1292 |
} |
1293 |
ezxml_free(fl); /* done with XML file */ |
1294 |
if (!check_bsdf_data(dp)) { |
1295 |
sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path); |
1296 |
error(WARNING, errmsg); |
1297 |
free_BSDF(dp); |
1298 |
dp = NULL; |
1299 |
} |
1300 |
return(dp); |
1301 |
} |
1302 |
|
1303 |
|
1304 |
void |
1305 |
free_BSDF( /* free BSDF data structure */ |
1306 |
struct BSDF_data *b |
1307 |
) |
1308 |
{ |
1309 |
if (b == NULL) |
1310 |
return; |
1311 |
if (b->mgf != NULL) |
1312 |
free(b->mgf); |
1313 |
if (b->bsdf != NULL) |
1314 |
free(b->bsdf); |
1315 |
free(b); |
1316 |
} |
1317 |
|
1318 |
|
1319 |
int |
1320 |
r_BSDF_incvec( /* compute random input vector at given location */ |
1321 |
FVECT v, |
1322 |
struct BSDF_data *b, |
1323 |
int i, |
1324 |
double rv, |
1325 |
MAT4 xm |
1326 |
) |
1327 |
{ |
1328 |
FVECT pert; |
1329 |
double rad; |
1330 |
int j; |
1331 |
|
1332 |
if (!getBSDF_incvec(v, b, i)) |
1333 |
return(0); |
1334 |
rad = sqrt(getBSDF_incohm(b, i) / PI); |
1335 |
multisamp(pert, 3, rv); |
1336 |
for (j = 0; j < 3; j++) |
1337 |
v[j] += rad*(2.*pert[j] - 1.); |
1338 |
if (xm != NULL) |
1339 |
multv3(v, v, xm); |
1340 |
return(normalize(v) != 0.0); |
1341 |
} |
1342 |
|
1343 |
|
1344 |
int |
1345 |
r_BSDF_outvec( /* compute random output vector at given location */ |
1346 |
FVECT v, |
1347 |
struct BSDF_data *b, |
1348 |
int o, |
1349 |
double rv, |
1350 |
MAT4 xm |
1351 |
) |
1352 |
{ |
1353 |
FVECT pert; |
1354 |
double rad; |
1355 |
int j; |
1356 |
|
1357 |
if (!getBSDF_outvec(v, b, o)) |
1358 |
return(0); |
1359 |
rad = sqrt(getBSDF_outohm(b, o) / PI); |
1360 |
multisamp(pert, 3, rv); |
1361 |
for (j = 0; j < 3; j++) |
1362 |
v[j] += rad*(2.*pert[j] - 1.); |
1363 |
if (xm != NULL) |
1364 |
multv3(v, v, xm); |
1365 |
return(normalize(v) != 0.0); |
1366 |
} |
1367 |
|
1368 |
|
1369 |
static int |
1370 |
addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
1371 |
char *xfarg[], |
1372 |
FVECT xp, |
1373 |
FVECT yp, |
1374 |
FVECT zp |
1375 |
) |
1376 |
{ |
1377 |
static char bufs[3][16]; |
1378 |
int bn = 0; |
1379 |
char **xfp = xfarg; |
1380 |
double theta; |
1381 |
|
1382 |
if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) { |
1383 |
/* Special case for X' along Z-axis */ |
1384 |
theta = -atan2(yp[0], yp[1]); |
1385 |
*xfp++ = "-ry"; |
1386 |
*xfp++ = xp[2] < 0.0 ? "90" : "-90"; |
1387 |
*xfp++ = "-rz"; |
1388 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1389 |
*xfp++ = bufs[bn++]; |
1390 |
return(xfp - xfarg); |
1391 |
} |
1392 |
theta = atan2(yp[2], zp[2]); |
1393 |
if (!FEQ(theta,0.0)) { |
1394 |
*xfp++ = "-rx"; |
1395 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1396 |
*xfp++ = bufs[bn++]; |
1397 |
} |
1398 |
theta = asin(-xp[2]); |
1399 |
if (!FEQ(theta,0.0)) { |
1400 |
*xfp++ = "-ry"; |
1401 |
sprintf(bufs[bn], " %f", theta*(180./PI)); |
1402 |
*xfp++ = bufs[bn++]; |
1403 |
} |
1404 |
theta = atan2(xp[1], xp[0]); |
1405 |
if (!FEQ(theta,0.0)) { |
1406 |
*xfp++ = "-rz"; |
1407 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
1408 |
*xfp++ = bufs[bn++]; |
1409 |
} |
1410 |
*xfp = NULL; |
1411 |
return(xfp - xfarg); |
1412 |
} |
1413 |
|
1414 |
|
1415 |
int |
1416 |
getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */ |
1417 |
MAT4 xm, |
1418 |
FVECT nrm, |
1419 |
UpDir ud, |
1420 |
char *xfbuf |
1421 |
) |
1422 |
{ |
1423 |
char *xfargs[7]; |
1424 |
XF myxf; |
1425 |
FVECT updir, xdest, ydest; |
1426 |
int i; |
1427 |
|
1428 |
updir[0] = updir[1] = updir[2] = 0.; |
1429 |
switch (ud) { |
1430 |
case UDzneg: |
1431 |
updir[2] = -1.; |
1432 |
break; |
1433 |
case UDyneg: |
1434 |
updir[1] = -1.; |
1435 |
break; |
1436 |
case UDxneg: |
1437 |
updir[0] = -1.; |
1438 |
break; |
1439 |
case UDxpos: |
1440 |
updir[0] = 1.; |
1441 |
break; |
1442 |
case UDypos: |
1443 |
updir[1] = 1.; |
1444 |
break; |
1445 |
case UDzpos: |
1446 |
updir[2] = 1.; |
1447 |
break; |
1448 |
case UDunknown: |
1449 |
return(0); |
1450 |
} |
1451 |
fcross(xdest, updir, nrm); |
1452 |
if (normalize(xdest) == 0.0) |
1453 |
return(0); |
1454 |
fcross(ydest, nrm, xdest); |
1455 |
xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
1456 |
copymat4(xm, myxf.xfm); |
1457 |
if (xfbuf == NULL) |
1458 |
return(1); |
1459 |
/* return xf arguments as well */ |
1460 |
for (i = 0; xfargs[i] != NULL; i++) { |
1461 |
*xfbuf++ = ' '; |
1462 |
strcpy(xfbuf, xfargs[i]); |
1463 |
while (*xfbuf) ++xfbuf; |
1464 |
} |
1465 |
return(1); |
1466 |
} |
1467 |
|
1468 |
/*######### END DEPRECATED ROUTINES #######*/ |
1469 |
/*################################################################*/ |