1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf.c,v 2.49 2014/12/08 23:51:12 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* bsdf.c |
6 |
* |
7 |
* Definitions for bidirectional scattering distribution functions. |
8 |
* |
9 |
* Created by Greg Ward on 1/10/11. |
10 |
* |
11 |
*/ |
12 |
|
13 |
#define _USE_MATH_DEFINES |
14 |
#include <stdio.h> |
15 |
#include <stdlib.h> |
16 |
#include <string.h> |
17 |
#include <math.h> |
18 |
#include <ctype.h> |
19 |
#include "ezxml.h" |
20 |
#include "hilbert.h" |
21 |
#include "bsdf.h" |
22 |
#include "bsdf_m.h" |
23 |
#include "bsdf_t.h" |
24 |
|
25 |
/* English ASCII strings corresponding to ennumerated errors */ |
26 |
const char *SDerrorEnglish[] = { |
27 |
"No error", |
28 |
"Memory error", |
29 |
"File input/output error", |
30 |
"File format error", |
31 |
"Illegal argument", |
32 |
"Invalid data", |
33 |
"Unsupported feature", |
34 |
"Internal program error", |
35 |
"Unknown error" |
36 |
}; |
37 |
|
38 |
/* Pointer to error list in preferred language */ |
39 |
const char **SDerrorList = SDerrorEnglish; |
40 |
|
41 |
/* Additional information on last error (ASCII English) */ |
42 |
char SDerrorDetail[256]; |
43 |
|
44 |
/* Empty distribution for getCDist() calls that fail for some reason */ |
45 |
const SDCDst SDemptyCD; |
46 |
|
47 |
/* Cache of loaded BSDFs */ |
48 |
struct SDCache_s *SDcacheList = NULL; |
49 |
|
50 |
/* Retain BSDFs in cache list */ |
51 |
int SDretainSet = SDretainNone; |
52 |
|
53 |
/* Report any error to the indicated stream */ |
54 |
SDError |
55 |
SDreportError(SDError ec, FILE *fp) |
56 |
{ |
57 |
if (!ec) |
58 |
return SDEnone; |
59 |
if ((ec < SDEnone) | (ec > SDEunknown)) { |
60 |
SDerrorDetail[0] = '\0'; |
61 |
ec = SDEunknown; |
62 |
} |
63 |
if (fp == NULL) |
64 |
return ec; |
65 |
fputs(SDerrorList[ec], fp); |
66 |
if (SDerrorDetail[0]) { |
67 |
fputs(": ", fp); |
68 |
fputs(SDerrorDetail, fp); |
69 |
} |
70 |
fputc('\n', fp); |
71 |
if (fp != stderr) |
72 |
fflush(fp); |
73 |
return ec; |
74 |
} |
75 |
|
76 |
static double |
77 |
to_meters( /* return factor to convert given unit to meters */ |
78 |
const char *unit |
79 |
) |
80 |
{ |
81 |
if (unit == NULL) return(1.); /* safe assumption? */ |
82 |
if (!strcasecmp(unit, "Meter")) return(1.); |
83 |
if (!strcasecmp(unit, "Foot")) return(.3048); |
84 |
if (!strcasecmp(unit, "Inch")) return(.0254); |
85 |
if (!strcasecmp(unit, "Centimeter")) return(.01); |
86 |
if (!strcasecmp(unit, "Millimeter")) return(.001); |
87 |
sprintf(SDerrorDetail, "Unknown dimensional unit '%s'", unit); |
88 |
return(-1.); |
89 |
} |
90 |
|
91 |
/* Load geometric dimensions and description (if any) */ |
92 |
static SDError |
93 |
SDloadGeometry(SDData *sd, ezxml_t wtl) |
94 |
{ |
95 |
ezxml_t node, matl, geom; |
96 |
double cfact; |
97 |
const char *fmt = NULL, *mgfstr; |
98 |
|
99 |
SDerrorDetail[0] = '\0'; |
100 |
sd->matn[0] = '\0'; sd->makr[0] = '\0'; |
101 |
sd->dim[0] = sd->dim[1] = sd->dim[2] = 0; |
102 |
matl = ezxml_child(wtl, "Material"); |
103 |
if (matl != NULL) { /* get material info. */ |
104 |
if ((node = ezxml_child(matl, "Name")) != NULL) { |
105 |
strncpy(sd->matn, ezxml_txt(node), SDnameLn); |
106 |
if (sd->matn[SDnameLn-1]) |
107 |
strcpy(sd->matn+(SDnameLn-4), "..."); |
108 |
} |
109 |
if ((node = ezxml_child(matl, "Manufacturer")) != NULL) { |
110 |
strncpy(sd->makr, ezxml_txt(node), SDnameLn); |
111 |
if (sd->makr[SDnameLn-1]) |
112 |
strcpy(sd->makr+(SDnameLn-4), "..."); |
113 |
} |
114 |
if ((node = ezxml_child(matl, "Width")) != NULL) |
115 |
sd->dim[0] = atof(ezxml_txt(node)) * |
116 |
to_meters(ezxml_attr(node, "unit")); |
117 |
if ((node = ezxml_child(matl, "Height")) != NULL) |
118 |
sd->dim[1] = atof(ezxml_txt(node)) * |
119 |
to_meters(ezxml_attr(node, "unit")); |
120 |
if ((node = ezxml_child(matl, "Thickness")) != NULL) |
121 |
sd->dim[2] = atof(ezxml_txt(node)) * |
122 |
to_meters(ezxml_attr(node, "unit")); |
123 |
if ((sd->dim[0] < 0) | (sd->dim[1] < 0) | (sd->dim[2] < 0)) { |
124 |
if (!SDerrorDetail[0]) |
125 |
sprintf(SDerrorDetail, "Negative dimension in \"%s\"", |
126 |
sd->name); |
127 |
return SDEdata; |
128 |
} |
129 |
} |
130 |
sd->mgf = NULL; |
131 |
geom = ezxml_child(wtl, "Geometry"); |
132 |
if (geom == NULL) /* no actual geometry? */ |
133 |
return SDEnone; |
134 |
fmt = ezxml_attr(geom, "format"); |
135 |
if (fmt != NULL && strcasecmp(fmt, "MGF")) { |
136 |
sprintf(SDerrorDetail, |
137 |
"Unrecognized geometry format '%s' in \"%s\"", |
138 |
fmt, sd->name); |
139 |
return SDEsupport; |
140 |
} |
141 |
if ((node = ezxml_child(geom, "MGFblock")) == NULL || |
142 |
(mgfstr = ezxml_txt(node)) == NULL) |
143 |
return SDEnone; |
144 |
while (isspace(*mgfstr)) |
145 |
++mgfstr; |
146 |
if (!*mgfstr) |
147 |
return SDEnone; |
148 |
cfact = to_meters(ezxml_attr(node, "unit")); |
149 |
if (cfact <= 0) |
150 |
return SDEformat; |
151 |
sd->mgf = (char *)malloc(strlen(mgfstr)+32); |
152 |
if (sd->mgf == NULL) { |
153 |
strcpy(SDerrorDetail, "Out of memory in SDloadGeometry"); |
154 |
return SDEmemory; |
155 |
} |
156 |
if (cfact < 0.99 || cfact > 1.01) |
157 |
sprintf(sd->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
158 |
else |
159 |
strcpy(sd->mgf, mgfstr); |
160 |
return SDEnone; |
161 |
} |
162 |
|
163 |
/* Load a BSDF struct from the given file (free first and keep name) */ |
164 |
SDError |
165 |
SDloadFile(SDData *sd, const char *fname) |
166 |
{ |
167 |
SDError lastErr; |
168 |
ezxml_t fl, wtl; |
169 |
|
170 |
if ((sd == NULL) | (fname == NULL || !*fname)) |
171 |
return SDEargument; |
172 |
/* free old data, keeping name */ |
173 |
SDfreeBSDF(sd); |
174 |
/* parse XML file */ |
175 |
fl = ezxml_parse_file(fname); |
176 |
if (fl == NULL) { |
177 |
sprintf(SDerrorDetail, "Cannot open BSDF \"%s\"", fname); |
178 |
return SDEfile; |
179 |
} |
180 |
if (ezxml_error(fl)[0]) { |
181 |
sprintf(SDerrorDetail, "BSDF \"%s\" %s", fname, ezxml_error(fl)); |
182 |
ezxml_free(fl); |
183 |
return SDEformat; |
184 |
} |
185 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
186 |
sprintf(SDerrorDetail, |
187 |
"BSDF \"%s\": top level node not 'WindowElement'", |
188 |
sd->name); |
189 |
ezxml_free(fl); |
190 |
return SDEformat; |
191 |
} |
192 |
wtl = ezxml_child(fl, "FileType"); |
193 |
if (wtl != NULL && strcmp(ezxml_txt(wtl), "BSDF")) { |
194 |
sprintf(SDerrorDetail, |
195 |
"XML \"%s\": wrong FileType (must be 'BSDF')", |
196 |
sd->name); |
197 |
ezxml_free(fl); |
198 |
return SDEformat; |
199 |
} |
200 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
201 |
if (wtl == NULL) { |
202 |
sprintf(SDerrorDetail, "BSDF \"%s\": no optical layers", |
203 |
sd->name); |
204 |
ezxml_free(fl); |
205 |
return SDEformat; |
206 |
} |
207 |
/* load geometry if present */ |
208 |
lastErr = SDloadGeometry(sd, wtl); |
209 |
if (lastErr) { |
210 |
ezxml_free(fl); |
211 |
return lastErr; |
212 |
} |
213 |
/* try loading variable resolution data */ |
214 |
lastErr = SDloadTre(sd, wtl); |
215 |
/* check our result */ |
216 |
if (lastErr == SDEsupport) /* try matrix BSDF if not tree data */ |
217 |
lastErr = SDloadMtx(sd, wtl); |
218 |
|
219 |
/* done with XML file */ |
220 |
ezxml_free(fl); |
221 |
|
222 |
if (lastErr) { /* was there a load error? */ |
223 |
SDfreeBSDF(sd); |
224 |
return lastErr; |
225 |
} |
226 |
/* remove any insignificant components */ |
227 |
if (sd->rf != NULL && sd->rf->maxHemi <= .001) { |
228 |
SDfreeSpectralDF(sd->rf); sd->rf = NULL; |
229 |
} |
230 |
if (sd->rb != NULL && sd->rb->maxHemi <= .001) { |
231 |
SDfreeSpectralDF(sd->rb); sd->rb = NULL; |
232 |
} |
233 |
if (sd->tf != NULL && sd->tf->maxHemi <= .001) { |
234 |
SDfreeSpectralDF(sd->tf); sd->tf = NULL; |
235 |
} |
236 |
if (sd->tb != NULL && sd->tb->maxHemi <= .001) { |
237 |
SDfreeSpectralDF(sd->tb); sd->tb = NULL; |
238 |
} |
239 |
/* return success */ |
240 |
return SDEnone; |
241 |
} |
242 |
|
243 |
/* Allocate new spectral distribution function */ |
244 |
SDSpectralDF * |
245 |
SDnewSpectralDF(int nc) |
246 |
{ |
247 |
SDSpectralDF *df; |
248 |
|
249 |
if (nc <= 0) { |
250 |
strcpy(SDerrorDetail, "Zero component spectral DF request"); |
251 |
return NULL; |
252 |
} |
253 |
df = (SDSpectralDF *)malloc(sizeof(SDSpectralDF) + |
254 |
(nc-1)*sizeof(SDComponent)); |
255 |
if (df == NULL) { |
256 |
sprintf(SDerrorDetail, |
257 |
"Cannot allocate %d component spectral DF", nc); |
258 |
return NULL; |
259 |
} |
260 |
df->minProjSA = .0; |
261 |
df->maxHemi = .0; |
262 |
df->ncomp = nc; |
263 |
memset(df->comp, 0, nc*sizeof(SDComponent)); |
264 |
return df; |
265 |
} |
266 |
|
267 |
/* Add component(s) to spectral distribution function */ |
268 |
SDSpectralDF * |
269 |
SDaddComponent(SDSpectralDF *odf, int nadd) |
270 |
{ |
271 |
SDSpectralDF *df; |
272 |
|
273 |
if (odf == NULL) |
274 |
return SDnewSpectralDF(nadd); |
275 |
if (nadd <= 0) |
276 |
return odf; |
277 |
df = (SDSpectralDF *)realloc(odf, sizeof(SDSpectralDF) + |
278 |
(odf->ncomp+nadd-1)*sizeof(SDComponent)); |
279 |
if (df == NULL) { |
280 |
sprintf(SDerrorDetail, |
281 |
"Cannot add %d component(s) to spectral DF", nadd); |
282 |
SDfreeSpectralDF(odf); |
283 |
return NULL; |
284 |
} |
285 |
memset(df->comp+df->ncomp, 0, nadd*sizeof(SDComponent)); |
286 |
df->ncomp += nadd; |
287 |
return df; |
288 |
} |
289 |
|
290 |
/* Free cached cumulative distributions for BSDF component */ |
291 |
void |
292 |
SDfreeCumulativeCache(SDSpectralDF *df) |
293 |
{ |
294 |
int n; |
295 |
SDCDst *cdp; |
296 |
|
297 |
if (df == NULL) |
298 |
return; |
299 |
for (n = df->ncomp; n-- > 0; ) |
300 |
while ((cdp = df->comp[n].cdList) != NULL) { |
301 |
df->comp[n].cdList = cdp->next; |
302 |
free(cdp); |
303 |
} |
304 |
} |
305 |
|
306 |
/* Free a spectral distribution function */ |
307 |
void |
308 |
SDfreeSpectralDF(SDSpectralDF *df) |
309 |
{ |
310 |
int n; |
311 |
|
312 |
if (df == NULL) |
313 |
return; |
314 |
SDfreeCumulativeCache(df); |
315 |
for (n = df->ncomp; n-- > 0; ) |
316 |
if (df->comp[n].dist != NULL) |
317 |
(*df->comp[n].func->freeSC)(df->comp[n].dist); |
318 |
free(df); |
319 |
} |
320 |
|
321 |
/* Shorten file path to useable BSDF name, removing suffix */ |
322 |
void |
323 |
SDclipName(char *res, const char *fname) |
324 |
{ |
325 |
const char *cp, *dot = NULL; |
326 |
|
327 |
for (cp = fname; *cp; cp++) |
328 |
if (*cp == '.') |
329 |
dot = cp; |
330 |
if ((dot == NULL) | (dot < fname+2)) |
331 |
dot = cp; |
332 |
if (dot - fname >= SDnameLn) |
333 |
fname = dot - SDnameLn + 1; |
334 |
while (fname < dot) |
335 |
*res++ = *fname++; |
336 |
*res = '\0'; |
337 |
} |
338 |
|
339 |
/* Initialize an unused BSDF struct (simply clears to zeroes) */ |
340 |
void |
341 |
SDclearBSDF(SDData *sd, const char *fname) |
342 |
{ |
343 |
if (sd == NULL) |
344 |
return; |
345 |
memset(sd, 0, sizeof(SDData)); |
346 |
if (fname == NULL) |
347 |
return; |
348 |
SDclipName(sd->name, fname); |
349 |
} |
350 |
|
351 |
/* Free data associated with BSDF struct */ |
352 |
void |
353 |
SDfreeBSDF(SDData *sd) |
354 |
{ |
355 |
if (sd == NULL) |
356 |
return; |
357 |
if (sd->mgf != NULL) { |
358 |
free(sd->mgf); |
359 |
sd->mgf = NULL; |
360 |
} |
361 |
if (sd->rf != NULL) { |
362 |
SDfreeSpectralDF(sd->rf); |
363 |
sd->rf = NULL; |
364 |
} |
365 |
if (sd->rb != NULL) { |
366 |
SDfreeSpectralDF(sd->rb); |
367 |
sd->rb = NULL; |
368 |
} |
369 |
if (sd->tf != NULL) { |
370 |
SDfreeSpectralDF(sd->tf); |
371 |
sd->tf = NULL; |
372 |
} |
373 |
if (sd->tb != NULL) { |
374 |
SDfreeSpectralDF(sd->tb); |
375 |
sd->tb = NULL; |
376 |
} |
377 |
sd->rLambFront.cieY = .0; |
378 |
sd->rLambFront.spec.flags = 0; |
379 |
sd->rLambBack.cieY = .0; |
380 |
sd->rLambBack.spec.flags = 0; |
381 |
sd->tLamb.cieY = .0; |
382 |
sd->tLamb.spec.flags = 0; |
383 |
} |
384 |
|
385 |
/* Find writeable BSDF by name, or allocate new cache entry if absent */ |
386 |
SDData * |
387 |
SDgetCache(const char *bname) |
388 |
{ |
389 |
struct SDCache_s *sdl; |
390 |
char sdnam[SDnameLn]; |
391 |
|
392 |
if (bname == NULL) |
393 |
return NULL; |
394 |
|
395 |
SDclipName(sdnam, bname); |
396 |
for (sdl = SDcacheList; sdl != NULL; sdl = sdl->next) |
397 |
if (!strcmp(sdl->bsdf.name, sdnam)) { |
398 |
sdl->refcnt++; |
399 |
return &sdl->bsdf; |
400 |
} |
401 |
|
402 |
sdl = (struct SDCache_s *)calloc(1, sizeof(struct SDCache_s)); |
403 |
if (sdl == NULL) |
404 |
return NULL; |
405 |
|
406 |
strcpy(sdl->bsdf.name, sdnam); |
407 |
sdl->next = SDcacheList; |
408 |
SDcacheList = sdl; |
409 |
|
410 |
sdl->refcnt = 1; |
411 |
return &sdl->bsdf; |
412 |
} |
413 |
|
414 |
/* Get loaded BSDF from cache (or load and cache it on first call) */ |
415 |
/* Report any problem to stderr and return NULL on failure */ |
416 |
const SDData * |
417 |
SDcacheFile(const char *fname) |
418 |
{ |
419 |
SDData *sd; |
420 |
SDError ec; |
421 |
|
422 |
if (fname == NULL || !*fname) |
423 |
return NULL; |
424 |
SDerrorDetail[0] = '\0'; |
425 |
if ((sd = SDgetCache(fname)) == NULL) { |
426 |
SDreportError(SDEmemory, stderr); |
427 |
return NULL; |
428 |
} |
429 |
if (!SDisLoaded(sd) && (ec = SDloadFile(sd, fname))) { |
430 |
SDreportError(ec, stderr); |
431 |
SDfreeCache(sd); |
432 |
return NULL; |
433 |
} |
434 |
return sd; |
435 |
} |
436 |
|
437 |
/* Free a BSDF from our cache (clear all if NULL) */ |
438 |
void |
439 |
SDfreeCache(const SDData *sd) |
440 |
{ |
441 |
struct SDCache_s *sdl, *sdLast = NULL; |
442 |
|
443 |
if (sd == NULL) { /* free entire list */ |
444 |
while ((sdl = SDcacheList) != NULL) { |
445 |
SDcacheList = sdl->next; |
446 |
SDfreeBSDF(&sdl->bsdf); |
447 |
free(sdl); |
448 |
} |
449 |
return; |
450 |
} |
451 |
for (sdl = SDcacheList; sdl != NULL; sdl = (sdLast=sdl)->next) |
452 |
if (&sdl->bsdf == sd) |
453 |
break; |
454 |
if (sdl == NULL || (sdl->refcnt -= (sdl->refcnt > 0))) |
455 |
return; /* missing or still in use */ |
456 |
/* keep unreferenced data? */ |
457 |
if (SDisLoaded(sd) && SDretainSet) { |
458 |
if (SDretainSet == SDretainAll) |
459 |
return; /* keep everything */ |
460 |
/* else free cumulative data */ |
461 |
SDfreeCumulativeCache(sd->rf); |
462 |
SDfreeCumulativeCache(sd->rb); |
463 |
SDfreeCumulativeCache(sd->tf); |
464 |
SDfreeCumulativeCache(sd->tb); |
465 |
return; |
466 |
} |
467 |
/* remove from list and free */ |
468 |
if (sdLast == NULL) |
469 |
SDcacheList = sdl->next; |
470 |
else |
471 |
sdLast->next = sdl->next; |
472 |
SDfreeBSDF(&sdl->bsdf); |
473 |
free(sdl); |
474 |
} |
475 |
|
476 |
/* Sample an individual BSDF component */ |
477 |
SDError |
478 |
SDsampComponent(SDValue *sv, FVECT ioVec, double randX, SDComponent *sdc) |
479 |
{ |
480 |
float coef[SDmaxCh]; |
481 |
SDError ec; |
482 |
FVECT inVec; |
483 |
const SDCDst *cd; |
484 |
double d; |
485 |
int n; |
486 |
/* check arguments */ |
487 |
if ((sv == NULL) | (ioVec == NULL) | (sdc == NULL)) |
488 |
return SDEargument; |
489 |
/* get cumulative distribution */ |
490 |
VCOPY(inVec, ioVec); |
491 |
sv->cieY = 0; |
492 |
cd = (*sdc->func->getCDist)(inVec, sdc); |
493 |
if (cd != NULL) |
494 |
sv->cieY = cd->cTotal; |
495 |
if (sv->cieY <= 1e-6) { /* nothing to sample? */ |
496 |
sv->spec = c_dfcolor; |
497 |
memset(ioVec, 0, 3*sizeof(double)); |
498 |
return SDEnone; |
499 |
} |
500 |
/* compute sample direction */ |
501 |
ec = (*sdc->func->sampCDist)(ioVec, randX, cd); |
502 |
if (ec) |
503 |
return ec; |
504 |
/* get BSDF color */ |
505 |
n = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc); |
506 |
if (n <= 0) { |
507 |
strcpy(SDerrorDetail, "BSDF sample value error"); |
508 |
return SDEinternal; |
509 |
} |
510 |
sv->spec = sdc->cspec[0]; |
511 |
d = coef[0]; |
512 |
while (--n) { |
513 |
c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]); |
514 |
d += coef[n]; |
515 |
} |
516 |
/* make sure everything is set */ |
517 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
518 |
return SDEnone; |
519 |
} |
520 |
|
521 |
#define MS_MAXDIM 15 |
522 |
|
523 |
/* Convert 1-dimensional random variable to N-dimensional */ |
524 |
void |
525 |
SDmultiSamp(double t[], int n, double randX) |
526 |
{ |
527 |
unsigned nBits; |
528 |
double scale; |
529 |
bitmask_t ndx, coord[MS_MAXDIM]; |
530 |
|
531 |
if (n <= 0) /* check corner cases */ |
532 |
return; |
533 |
if (randX < 0) randX = 0; |
534 |
else if (randX >= 1.) randX = 0.999999999999999; |
535 |
if (n == 1) { |
536 |
t[0] = randX; |
537 |
return; |
538 |
} |
539 |
while (n > MS_MAXDIM) /* punt for higher dimensions */ |
540 |
t[--n] = rand()*(1./(RAND_MAX+.5)); |
541 |
nBits = (8*sizeof(bitmask_t) - 1) / n; |
542 |
ndx = randX * (double)((bitmask_t)1 << (nBits*n)); |
543 |
/* get coordinate on Hilbert curve */ |
544 |
hilbert_i2c(n, nBits, ndx, coord); |
545 |
/* convert back to [0,1) range */ |
546 |
scale = 1. / (double)((bitmask_t)1 << nBits); |
547 |
while (n--) |
548 |
t[n] = scale * ((double)coord[n] + rand()*(1./(RAND_MAX+.5))); |
549 |
} |
550 |
|
551 |
#undef MS_MAXDIM |
552 |
|
553 |
/* Generate diffuse hemispherical sample */ |
554 |
static void |
555 |
SDdiffuseSamp(FVECT outVec, int outFront, double randX) |
556 |
{ |
557 |
/* convert to position on hemisphere */ |
558 |
SDmultiSamp(outVec, 2, randX); |
559 |
SDsquare2disk(outVec, outVec[0], outVec[1]); |
560 |
outVec[2] = 1. - outVec[0]*outVec[0] - outVec[1]*outVec[1]; |
561 |
outVec[2] = sqrt(outVec[2]*(outVec[2]>0)); |
562 |
if (!outFront) /* going out back? */ |
563 |
outVec[2] = -outVec[2]; |
564 |
} |
565 |
|
566 |
/* Query projected solid angle coverage for non-diffuse BSDF direction */ |
567 |
SDError |
568 |
SDsizeBSDF(double *projSA, const FVECT v1, const RREAL *v2, |
569 |
int qflags, const SDData *sd) |
570 |
{ |
571 |
SDSpectralDF *rdf, *tdf; |
572 |
SDError ec; |
573 |
int i; |
574 |
/* check arguments */ |
575 |
if ((projSA == NULL) | (v1 == NULL) | (sd == NULL)) |
576 |
return SDEargument; |
577 |
/* initialize extrema */ |
578 |
switch (qflags) { |
579 |
case SDqueryMax: |
580 |
projSA[0] = .0; |
581 |
break; |
582 |
case SDqueryMin+SDqueryMax: |
583 |
projSA[1] = .0; |
584 |
/* fall through */ |
585 |
case SDqueryMin: |
586 |
projSA[0] = 10.; |
587 |
break; |
588 |
case 0: |
589 |
return SDEargument; |
590 |
} |
591 |
if (v1[2] > 0) { /* front surface query? */ |
592 |
rdf = sd->rf; |
593 |
tdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
594 |
} else { |
595 |
rdf = sd->rb; |
596 |
tdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
597 |
} |
598 |
if (v2 != NULL) /* bidirectional? */ |
599 |
if (v1[2] > 0 ^ v2[2] > 0) |
600 |
rdf = NULL; |
601 |
else |
602 |
tdf = NULL; |
603 |
ec = SDEdata; /* run through components */ |
604 |
for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) { |
605 |
ec = (*rdf->comp[i].func->queryProjSA)(projSA, v1, v2, |
606 |
qflags, &rdf->comp[i]); |
607 |
if (ec) |
608 |
return ec; |
609 |
} |
610 |
for (i = (tdf==NULL) ? 0 : tdf->ncomp; i--; ) { |
611 |
ec = (*tdf->comp[i].func->queryProjSA)(projSA, v1, v2, |
612 |
qflags, &tdf->comp[i]); |
613 |
if (ec) |
614 |
return ec; |
615 |
} |
616 |
if (ec) { /* all diffuse? */ |
617 |
projSA[0] = M_PI; |
618 |
if (qflags == SDqueryMin+SDqueryMax) |
619 |
projSA[1] = M_PI; |
620 |
} else if (qflags == SDqueryMin+SDqueryMax && projSA[0] > projSA[1]) |
621 |
projSA[0] = projSA[1]; |
622 |
return SDEnone; |
623 |
} |
624 |
|
625 |
/* Return BSDF for the given incident and scattered ray vectors */ |
626 |
SDError |
627 |
SDevalBSDF(SDValue *sv, const FVECT outVec, const FVECT inVec, const SDData *sd) |
628 |
{ |
629 |
int inFront, outFront; |
630 |
SDSpectralDF *sdf; |
631 |
float coef[SDmaxCh]; |
632 |
int nch, i; |
633 |
/* check arguments */ |
634 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL)) |
635 |
return SDEargument; |
636 |
/* whose side are we on? */ |
637 |
inFront = (inVec[2] > 0); |
638 |
outFront = (outVec[2] > 0); |
639 |
/* start with diffuse portion */ |
640 |
if (inFront & outFront) { |
641 |
*sv = sd->rLambFront; |
642 |
sdf = sd->rf; |
643 |
} else if (!(inFront | outFront)) { |
644 |
*sv = sd->rLambBack; |
645 |
sdf = sd->rb; |
646 |
} else if (inFront) { |
647 |
*sv = sd->tLamb; |
648 |
sdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
649 |
} else /* inBack */ { |
650 |
*sv = sd->tLamb; |
651 |
sdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
652 |
} |
653 |
sv->cieY *= 1./M_PI; |
654 |
/* add non-diffuse components */ |
655 |
i = (sdf != NULL) ? sdf->ncomp : 0; |
656 |
while (i-- > 0) { |
657 |
nch = (*sdf->comp[i].func->getBSDFs)(coef, outVec, inVec, |
658 |
&sdf->comp[i]); |
659 |
while (nch-- > 0) { |
660 |
c_cmix(&sv->spec, sv->cieY, &sv->spec, |
661 |
coef[nch], &sdf->comp[i].cspec[nch]); |
662 |
sv->cieY += coef[nch]; |
663 |
} |
664 |
} |
665 |
/* make sure everything is set */ |
666 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
667 |
return SDEnone; |
668 |
} |
669 |
|
670 |
/* Compute directional hemispherical scattering at this incident angle */ |
671 |
double |
672 |
SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd) |
673 |
{ |
674 |
double hsum; |
675 |
SDSpectralDF *rdf, *tdf; |
676 |
const SDCDst *cd; |
677 |
int i; |
678 |
/* check arguments */ |
679 |
if ((inVec == NULL) | (sd == NULL)) |
680 |
return .0; |
681 |
/* gather diffuse components */ |
682 |
if (inVec[2] > 0) { |
683 |
hsum = sd->rLambFront.cieY; |
684 |
rdf = sd->rf; |
685 |
tdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
686 |
} else /* !inFront */ { |
687 |
hsum = sd->rLambBack.cieY; |
688 |
rdf = sd->rb; |
689 |
tdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
690 |
} |
691 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
692 |
hsum = .0; |
693 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
694 |
hsum += sd->tLamb.cieY; |
695 |
/* gather non-diffuse components */ |
696 |
i = (((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR) & |
697 |
(rdf != NULL)) ? rdf->ncomp : 0; |
698 |
while (i-- > 0) { /* non-diffuse reflection */ |
699 |
cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
700 |
if (cd != NULL) |
701 |
hsum += cd->cTotal; |
702 |
} |
703 |
i = (((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT) & |
704 |
(tdf != NULL)) ? tdf->ncomp : 0; |
705 |
while (i-- > 0) { /* non-diffuse transmission */ |
706 |
cd = (*tdf->comp[i].func->getCDist)(inVec, &tdf->comp[i]); |
707 |
if (cd != NULL) |
708 |
hsum += cd->cTotal; |
709 |
} |
710 |
return hsum; |
711 |
} |
712 |
|
713 |
/* Sample BSDF direction based on the given random variable */ |
714 |
SDError |
715 |
SDsampBSDF(SDValue *sv, FVECT ioVec, double randX, int sflags, const SDData *sd) |
716 |
{ |
717 |
SDError ec; |
718 |
FVECT inVec; |
719 |
int inFront; |
720 |
SDSpectralDF *rdf, *tdf; |
721 |
double rdiff; |
722 |
float coef[SDmaxCh]; |
723 |
int i, j, n, nr; |
724 |
SDComponent *sdc; |
725 |
const SDCDst **cdarr = NULL; |
726 |
/* check arguments */ |
727 |
if ((sv == NULL) | (ioVec == NULL) | (sd == NULL) | |
728 |
(randX < 0) | (randX >= 1.)) |
729 |
return SDEargument; |
730 |
/* whose side are we on? */ |
731 |
VCOPY(inVec, ioVec); |
732 |
inFront = (inVec[2] > 0); |
733 |
/* remember diffuse portions */ |
734 |
if (inFront) { |
735 |
*sv = sd->rLambFront; |
736 |
rdf = sd->rf; |
737 |
tdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
738 |
} else /* !inFront */ { |
739 |
*sv = sd->rLambBack; |
740 |
rdf = sd->rb; |
741 |
tdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
742 |
} |
743 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
744 |
sv->cieY = .0; |
745 |
rdiff = sv->cieY; |
746 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
747 |
sv->cieY += sd->tLamb.cieY; |
748 |
/* gather non-diffuse components */ |
749 |
i = nr = (((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR) & |
750 |
(rdf != NULL)) ? rdf->ncomp : 0; |
751 |
j = (((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT) & |
752 |
(tdf != NULL)) ? tdf->ncomp : 0; |
753 |
n = i + j; |
754 |
if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL) |
755 |
return SDEmemory; |
756 |
while (j-- > 0) { /* non-diffuse transmission */ |
757 |
cdarr[i+j] = (*tdf->comp[j].func->getCDist)(inVec, &tdf->comp[j]); |
758 |
if (cdarr[i+j] == NULL) |
759 |
cdarr[i+j] = &SDemptyCD; |
760 |
sv->cieY += cdarr[i+j]->cTotal; |
761 |
} |
762 |
while (i-- > 0) { /* non-diffuse reflection */ |
763 |
cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
764 |
if (cdarr[i] == NULL) |
765 |
cdarr[i] = &SDemptyCD; |
766 |
sv->cieY += cdarr[i]->cTotal; |
767 |
} |
768 |
if (sv->cieY <= 1e-6) { /* anything to sample? */ |
769 |
sv->cieY = .0; |
770 |
memset(ioVec, 0, 3*sizeof(double)); |
771 |
return SDEnone; |
772 |
} |
773 |
/* scale random variable */ |
774 |
randX *= sv->cieY; |
775 |
/* diffuse reflection? */ |
776 |
if (randX < rdiff) { |
777 |
SDdiffuseSamp(ioVec, inFront, randX/rdiff); |
778 |
goto done; |
779 |
} |
780 |
randX -= rdiff; |
781 |
/* diffuse transmission? */ |
782 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) { |
783 |
if (randX < sd->tLamb.cieY) { |
784 |
sv->spec = sd->tLamb.spec; |
785 |
SDdiffuseSamp(ioVec, !inFront, randX/sd->tLamb.cieY); |
786 |
goto done; |
787 |
} |
788 |
randX -= sd->tLamb.cieY; |
789 |
} |
790 |
/* else one of cumulative dist. */ |
791 |
for (i = 0; i < n && randX > cdarr[i]->cTotal; i++) |
792 |
randX -= cdarr[i]->cTotal; |
793 |
if (i >= n) |
794 |
return SDEinternal; |
795 |
/* compute sample direction */ |
796 |
sdc = (i < nr) ? &rdf->comp[i] : &tdf->comp[i-nr]; |
797 |
ec = (*sdc->func->sampCDist)(ioVec, randX/cdarr[i]->cTotal, cdarr[i]); |
798 |
if (ec) |
799 |
return ec; |
800 |
/* compute color */ |
801 |
j = (*sdc->func->getBSDFs)(coef, ioVec, inVec, sdc); |
802 |
if (j <= 0) { |
803 |
sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error", |
804 |
sd->name); |
805 |
return SDEinternal; |
806 |
} |
807 |
sv->spec = sdc->cspec[0]; |
808 |
rdiff = coef[0]; |
809 |
while (--j) { |
810 |
c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]); |
811 |
rdiff += coef[j]; |
812 |
} |
813 |
done: |
814 |
if (cdarr != NULL) |
815 |
free(cdarr); |
816 |
/* make sure everything is set */ |
817 |
c_ccvt(&sv->spec, C_CSXY+C_CSSPEC); |
818 |
return SDEnone; |
819 |
} |
820 |
|
821 |
/* Compute World->BSDF transform from surface normal and up (Y) vector */ |
822 |
SDError |
823 |
SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec) |
824 |
{ |
825 |
if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL)) |
826 |
return SDEargument; |
827 |
VCOPY(vMtx[2], sNrm); |
828 |
if (normalize(vMtx[2]) == 0) |
829 |
return SDEargument; |
830 |
fcross(vMtx[0], uVec, vMtx[2]); |
831 |
if (normalize(vMtx[0]) == 0) |
832 |
return SDEargument; |
833 |
fcross(vMtx[1], vMtx[2], vMtx[0]); |
834 |
return SDEnone; |
835 |
} |
836 |
|
837 |
/* Compute inverse transform */ |
838 |
SDError |
839 |
SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]) |
840 |
{ |
841 |
RREAL mTmp[3][3]; |
842 |
double d; |
843 |
|
844 |
if ((iMtx == NULL) | (vMtx == NULL)) |
845 |
return SDEargument; |
846 |
/* compute determinant */ |
847 |
mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2]; |
848 |
mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1]; |
849 |
mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2]; |
850 |
d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2]; |
851 |
if (d == 0) { |
852 |
strcpy(SDerrorDetail, "Zero determinant in matrix inversion"); |
853 |
return SDEargument; |
854 |
} |
855 |
d = 1./d; /* invert matrix */ |
856 |
mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d; |
857 |
mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]); |
858 |
mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]); |
859 |
mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]); |
860 |
mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]); |
861 |
mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]); |
862 |
mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]); |
863 |
memcpy(iMtx, mTmp, sizeof(mTmp)); |
864 |
return SDEnone; |
865 |
} |
866 |
|
867 |
/* Transform and normalize direction (column) vector */ |
868 |
SDError |
869 |
SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec) |
870 |
{ |
871 |
FVECT vTmp; |
872 |
|
873 |
if ((resVec == NULL) | (inpVec == NULL)) |
874 |
return SDEargument; |
875 |
if (vMtx == NULL) { /* assume they just want to normalize */ |
876 |
if (resVec != inpVec) |
877 |
VCOPY(resVec, inpVec); |
878 |
return (normalize(resVec) > 0) ? SDEnone : SDEargument; |
879 |
} |
880 |
vTmp[0] = DOT(vMtx[0], inpVec); |
881 |
vTmp[1] = DOT(vMtx[1], inpVec); |
882 |
vTmp[2] = DOT(vMtx[2], inpVec); |
883 |
if (normalize(vTmp) == 0) |
884 |
return SDEargument; |
885 |
VCOPY(resVec, vTmp); |
886 |
return SDEnone; |
887 |
} |