| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: bsdf.c,v 2.61 2021/12/07 23:49:50 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 |
/* Maximum cache size for any given BSDF? */ |
| 54 |
unsigned long SDmaxCache = 0; /* 0 == unlimited */ |
| 55 |
|
| 56 |
/* Report any error to the indicated stream */ |
| 57 |
SDError |
| 58 |
SDreportError(SDError ec, FILE *fp) |
| 59 |
{ |
| 60 |
if (!ec) |
| 61 |
return SDEnone; |
| 62 |
if ((ec < SDEnone) | (ec > SDEunknown)) { |
| 63 |
SDerrorDetail[0] = '\0'; |
| 64 |
ec = SDEunknown; |
| 65 |
} |
| 66 |
if (fp == NULL) |
| 67 |
return ec; |
| 68 |
fputs(SDerrorList[ec], fp); |
| 69 |
if (SDerrorDetail[0]) { |
| 70 |
fputs(": ", fp); |
| 71 |
fputs(SDerrorDetail, fp); |
| 72 |
} |
| 73 |
fputc('\n', fp); |
| 74 |
if (fp != stderr) |
| 75 |
fflush(fp); |
| 76 |
return ec; |
| 77 |
} |
| 78 |
|
| 79 |
static double |
| 80 |
to_meters( /* return factor to convert given unit to meters */ |
| 81 |
const char *unit |
| 82 |
) |
| 83 |
{ |
| 84 |
if (unit == NULL) return(1.); /* safe assumption? */ |
| 85 |
if (!strcasecmp(unit, "Meter")) return(1.); |
| 86 |
if (!strcasecmp(unit, "Foot")) return(.3048); |
| 87 |
if (!strcasecmp(unit, "Inch")) return(.0254); |
| 88 |
if (!strcasecmp(unit, "Centimeter")) return(.01); |
| 89 |
if (!strcasecmp(unit, "Millimeter")) return(.001); |
| 90 |
sprintf(SDerrorDetail, "Unknown dimensional unit '%s'", unit); |
| 91 |
return(-1.); |
| 92 |
} |
| 93 |
|
| 94 |
/* Load geometric dimensions and description (if any) */ |
| 95 |
static SDError |
| 96 |
SDloadGeometry(SDData *sd, ezxml_t wtl) |
| 97 |
{ |
| 98 |
ezxml_t node, matl, geom; |
| 99 |
double cfact; |
| 100 |
const char *fmt = NULL, *mgfstr; |
| 101 |
|
| 102 |
SDerrorDetail[0] = '\0'; |
| 103 |
sd->matn[0] = '\0'; sd->makr[0] = '\0'; |
| 104 |
sd->dim[0] = sd->dim[1] = sd->dim[2] = 0; |
| 105 |
matl = ezxml_child(wtl, "Material"); |
| 106 |
if (matl != NULL) { /* get material info. */ |
| 107 |
if ((node = ezxml_child(matl, "Name")) != NULL) { |
| 108 |
strncpy(sd->matn, ezxml_txt(node), SDnameLn); |
| 109 |
if (sd->matn[SDnameLn-1]) |
| 110 |
strcpy(sd->matn+(SDnameLn-4), "..."); |
| 111 |
} |
| 112 |
if ((node = ezxml_child(matl, "Manufacturer")) != NULL) { |
| 113 |
strncpy(sd->makr, ezxml_txt(node), SDnameLn); |
| 114 |
if (sd->makr[SDnameLn-1]) |
| 115 |
strcpy(sd->makr+(SDnameLn-4), "..."); |
| 116 |
} |
| 117 |
if ((node = ezxml_child(matl, "Width")) != NULL) |
| 118 |
sd->dim[0] = atof(ezxml_txt(node)) * |
| 119 |
to_meters(ezxml_attr(node, "unit")); |
| 120 |
if ((node = ezxml_child(matl, "Height")) != NULL) |
| 121 |
sd->dim[1] = atof(ezxml_txt(node)) * |
| 122 |
to_meters(ezxml_attr(node, "unit")); |
| 123 |
if ((node = ezxml_child(matl, "Thickness")) != NULL) |
| 124 |
sd->dim[2] = atof(ezxml_txt(node)) * |
| 125 |
to_meters(ezxml_attr(node, "unit")); |
| 126 |
if ((sd->dim[0] < 0) | (sd->dim[1] < 0) | (sd->dim[2] < 0)) { |
| 127 |
if (!SDerrorDetail[0]) |
| 128 |
sprintf(SDerrorDetail, "Negative dimension in \"%s\"", |
| 129 |
sd->name); |
| 130 |
return SDEdata; |
| 131 |
} |
| 132 |
} |
| 133 |
sd->mgf = NULL; |
| 134 |
geom = ezxml_child(wtl, "Geometry"); |
| 135 |
if (geom == NULL) /* no actual geometry? */ |
| 136 |
return SDEnone; |
| 137 |
fmt = ezxml_attr(geom, "format"); |
| 138 |
if (fmt != NULL && strcasecmp(fmt, "MGF")) { |
| 139 |
sprintf(SDerrorDetail, |
| 140 |
"Unrecognized geometry format '%s' in \"%s\"", |
| 141 |
fmt, sd->name); |
| 142 |
return SDEsupport; |
| 143 |
} |
| 144 |
if ((node = ezxml_child(geom, "MGFblock")) == NULL || |
| 145 |
(mgfstr = ezxml_txt(node)) == NULL) |
| 146 |
return SDEnone; |
| 147 |
while (isspace(*mgfstr)) |
| 148 |
++mgfstr; |
| 149 |
if (!*mgfstr) |
| 150 |
return SDEnone; |
| 151 |
cfact = to_meters(ezxml_attr(node, "unit")); |
| 152 |
if (cfact <= 0) |
| 153 |
return SDEformat; |
| 154 |
sd->mgf = (char *)malloc(strlen(mgfstr)+32); |
| 155 |
if (sd->mgf == NULL) { |
| 156 |
strcpy(SDerrorDetail, "Out of memory in SDloadGeometry"); |
| 157 |
return SDEmemory; |
| 158 |
} |
| 159 |
if (cfact < 0.99 || cfact > 1.01) |
| 160 |
sprintf(sd->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
| 161 |
else |
| 162 |
strcpy(sd->mgf, mgfstr); |
| 163 |
return SDEnone; |
| 164 |
} |
| 165 |
|
| 166 |
/* Load a BSDF struct from the given file (free first and keep name) */ |
| 167 |
SDError |
| 168 |
SDloadFile(SDData *sd, const char *fname) |
| 169 |
{ |
| 170 |
SDError lastErr; |
| 171 |
ezxml_t fl, wtl; |
| 172 |
|
| 173 |
if ((sd == NULL) | (fname == NULL || !*fname)) |
| 174 |
return SDEargument; |
| 175 |
/* free old data, keeping name */ |
| 176 |
SDfreeBSDF(sd); |
| 177 |
/* parse XML file */ |
| 178 |
fl = ezxml_parse_file(fname); |
| 179 |
if (fl == NULL) { |
| 180 |
sprintf(SDerrorDetail, "Cannot open BSDF \"%s\"", fname); |
| 181 |
return SDEfile; |
| 182 |
} |
| 183 |
if (ezxml_error(fl)[0]) { |
| 184 |
sprintf(SDerrorDetail, "BSDF \"%s\" %s", fname, ezxml_error(fl)); |
| 185 |
ezxml_free(fl); |
| 186 |
return SDEformat; |
| 187 |
} |
| 188 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
| 189 |
sprintf(SDerrorDetail, |
| 190 |
"BSDF \"%s\": top level node not 'WindowElement'", |
| 191 |
sd->name); |
| 192 |
ezxml_free(fl); |
| 193 |
return SDEformat; |
| 194 |
} |
| 195 |
wtl = ezxml_child(fl, "FileType"); |
| 196 |
if (wtl != NULL && strcmp(ezxml_txt(wtl), "BSDF")) { |
| 197 |
sprintf(SDerrorDetail, |
| 198 |
"XML \"%s\": wrong FileType (must be 'BSDF')", |
| 199 |
sd->name); |
| 200 |
ezxml_free(fl); |
| 201 |
return SDEformat; |
| 202 |
} |
| 203 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
| 204 |
if (wtl == NULL) { |
| 205 |
sprintf(SDerrorDetail, "BSDF \"%s\": no optical layers", |
| 206 |
sd->name); |
| 207 |
ezxml_free(fl); |
| 208 |
return SDEformat; |
| 209 |
} |
| 210 |
/* load geometry if present */ |
| 211 |
lastErr = SDloadGeometry(sd, wtl); |
| 212 |
if (lastErr) { |
| 213 |
ezxml_free(fl); |
| 214 |
return lastErr; |
| 215 |
} |
| 216 |
/* try loading variable resolution data */ |
| 217 |
lastErr = SDloadTre(sd, wtl); |
| 218 |
/* check our result */ |
| 219 |
if (lastErr == SDEsupport) /* try matrix BSDF if not tree data */ |
| 220 |
lastErr = SDloadMtx(sd, wtl); |
| 221 |
|
| 222 |
/* done with XML file */ |
| 223 |
ezxml_free(fl); |
| 224 |
|
| 225 |
if (lastErr) { /* was there a load error? */ |
| 226 |
SDfreeBSDF(sd); |
| 227 |
return lastErr; |
| 228 |
} |
| 229 |
/* remove any insignificant components */ |
| 230 |
if (sd->rf != NULL && sd->rf->maxHemi <= .001) { |
| 231 |
SDfreeSpectralDF(sd->rf); sd->rf = NULL; |
| 232 |
} |
| 233 |
if (sd->rb != NULL && sd->rb->maxHemi <= .001) { |
| 234 |
SDfreeSpectralDF(sd->rb); sd->rb = NULL; |
| 235 |
} |
| 236 |
if (sd->tf != NULL && sd->tf->maxHemi <= .001) { |
| 237 |
SDfreeSpectralDF(sd->tf); sd->tf = NULL; |
| 238 |
} |
| 239 |
if (sd->tb != NULL && sd->tb->maxHemi <= .001) { |
| 240 |
SDfreeSpectralDF(sd->tb); sd->tb = NULL; |
| 241 |
} |
| 242 |
/* return success */ |
| 243 |
return SDEnone; |
| 244 |
} |
| 245 |
|
| 246 |
/* Allocate new spectral distribution function */ |
| 247 |
SDSpectralDF * |
| 248 |
SDnewSpectralDF(int nc) |
| 249 |
{ |
| 250 |
SDSpectralDF *df; |
| 251 |
|
| 252 |
if (nc <= 0) { |
| 253 |
strcpy(SDerrorDetail, "Zero component spectral DF request"); |
| 254 |
return NULL; |
| 255 |
} |
| 256 |
df = (SDSpectralDF *)malloc(sizeof(SDSpectralDF) + |
| 257 |
(nc-1)*sizeof(SDComponent)); |
| 258 |
if (df == NULL) { |
| 259 |
sprintf(SDerrorDetail, |
| 260 |
"Cannot allocate %d component spectral DF", nc); |
| 261 |
return NULL; |
| 262 |
} |
| 263 |
df->minProjSA = .0; |
| 264 |
df->maxHemi = .0; |
| 265 |
df->ncomp = nc; |
| 266 |
memset(df->comp, 0, nc*sizeof(SDComponent)); |
| 267 |
return df; |
| 268 |
} |
| 269 |
|
| 270 |
/* Add component(s) to spectral distribution function */ |
| 271 |
SDSpectralDF * |
| 272 |
SDaddComponent(SDSpectralDF *odf, int nadd) |
| 273 |
{ |
| 274 |
SDSpectralDF *df; |
| 275 |
|
| 276 |
if (odf == NULL) |
| 277 |
return SDnewSpectralDF(nadd); |
| 278 |
if (nadd <= 0) |
| 279 |
return odf; |
| 280 |
df = (SDSpectralDF *)realloc(odf, sizeof(SDSpectralDF) + |
| 281 |
(odf->ncomp+nadd-1)*sizeof(SDComponent)); |
| 282 |
if (df == NULL) { |
| 283 |
sprintf(SDerrorDetail, |
| 284 |
"Cannot add %d component(s) to spectral DF", nadd); |
| 285 |
SDfreeSpectralDF(odf); |
| 286 |
return NULL; |
| 287 |
} |
| 288 |
memset(df->comp+df->ncomp, 0, nadd*sizeof(SDComponent)); |
| 289 |
df->ncomp += nadd; |
| 290 |
return df; |
| 291 |
} |
| 292 |
|
| 293 |
/* Free cached cumulative distributions for BSDF component */ |
| 294 |
void |
| 295 |
SDfreeCumulativeCache(SDSpectralDF *df) |
| 296 |
{ |
| 297 |
int n; |
| 298 |
SDCDst *cdp; |
| 299 |
|
| 300 |
if (df == NULL) |
| 301 |
return; |
| 302 |
for (n = df->ncomp; n-- > 0; ) |
| 303 |
while ((cdp = df->comp[n].cdList) != NULL) { |
| 304 |
df->comp[n].cdList = cdp->next; |
| 305 |
free(cdp); |
| 306 |
} |
| 307 |
} |
| 308 |
|
| 309 |
/* Free a spectral distribution function */ |
| 310 |
void |
| 311 |
SDfreeSpectralDF(SDSpectralDF *df) |
| 312 |
{ |
| 313 |
int n; |
| 314 |
|
| 315 |
if (df == NULL) |
| 316 |
return; |
| 317 |
SDfreeCumulativeCache(df); |
| 318 |
for (n = df->ncomp; n-- > 0; ) |
| 319 |
if (df->comp[n].dist != NULL) |
| 320 |
(*df->comp[n].func->freeSC)(df->comp[n].dist); |
| 321 |
free(df); |
| 322 |
} |
| 323 |
|
| 324 |
/* Shorten file path to useable BSDF name, removing suffix */ |
| 325 |
void |
| 326 |
SDclipName(char *res, const char *fname) |
| 327 |
{ |
| 328 |
const char *cp, *dot = NULL; |
| 329 |
|
| 330 |
for (cp = fname; *cp; cp++) |
| 331 |
if (*cp == '.') |
| 332 |
dot = cp; |
| 333 |
else if (*cp == '/') |
| 334 |
dot = NULL; |
| 335 |
if ((dot == NULL) | (dot < fname+2)) |
| 336 |
dot = cp; |
| 337 |
if (dot - fname >= SDnameLn) |
| 338 |
fname = dot - SDnameLn + 1; |
| 339 |
while (fname < dot) |
| 340 |
*res++ = *fname++; |
| 341 |
*res = '\0'; |
| 342 |
} |
| 343 |
|
| 344 |
/* Initialize an unused BSDF struct (simply clears to zeroes) */ |
| 345 |
void |
| 346 |
SDclearBSDF(SDData *sd, const char *fname) |
| 347 |
{ |
| 348 |
if (sd == NULL) |
| 349 |
return; |
| 350 |
memset(sd, 0, sizeof(SDData)); |
| 351 |
if (fname == NULL) |
| 352 |
return; |
| 353 |
SDclipName(sd->name, fname); |
| 354 |
} |
| 355 |
|
| 356 |
/* Free data associated with BSDF struct */ |
| 357 |
void |
| 358 |
SDfreeBSDF(SDData *sd) |
| 359 |
{ |
| 360 |
if (sd == NULL) |
| 361 |
return; |
| 362 |
if (sd->mgf != NULL) { |
| 363 |
free(sd->mgf); |
| 364 |
sd->mgf = NULL; |
| 365 |
} |
| 366 |
if (sd->rf != NULL) { |
| 367 |
SDfreeSpectralDF(sd->rf); |
| 368 |
sd->rf = NULL; |
| 369 |
} |
| 370 |
if (sd->rb != NULL) { |
| 371 |
SDfreeSpectralDF(sd->rb); |
| 372 |
sd->rb = NULL; |
| 373 |
} |
| 374 |
if (sd->tf != NULL) { |
| 375 |
SDfreeSpectralDF(sd->tf); |
| 376 |
sd->tf = NULL; |
| 377 |
} |
| 378 |
if (sd->tb != NULL) { |
| 379 |
SDfreeSpectralDF(sd->tb); |
| 380 |
sd->tb = NULL; |
| 381 |
} |
| 382 |
sd->rLambFront.cieY = .0; |
| 383 |
sd->rLambFront.spec.flags = 0; |
| 384 |
sd->rLambBack.cieY = .0; |
| 385 |
sd->rLambBack.spec.flags = 0; |
| 386 |
sd->tLambFront.cieY = .0; |
| 387 |
sd->tLambFront.spec.flags = 0; |
| 388 |
sd->tLambBack.cieY = .0; |
| 389 |
sd->tLambBack.spec.flags = 0; |
| 390 |
} |
| 391 |
|
| 392 |
/* Find writeable BSDF by name, or allocate new cache entry if absent */ |
| 393 |
SDData * |
| 394 |
SDgetCache(const char *bname) |
| 395 |
{ |
| 396 |
struct SDCache_s *sdl; |
| 397 |
char sdnam[SDnameLn]; |
| 398 |
|
| 399 |
if (bname == NULL) |
| 400 |
return NULL; |
| 401 |
|
| 402 |
SDclipName(sdnam, bname); |
| 403 |
for (sdl = SDcacheList; sdl != NULL; sdl = sdl->next) |
| 404 |
if (!strcmp(sdl->bsdf.name, sdnam)) { |
| 405 |
sdl->refcnt++; |
| 406 |
return &sdl->bsdf; |
| 407 |
} |
| 408 |
|
| 409 |
sdl = (struct SDCache_s *)calloc(1, sizeof(struct SDCache_s)); |
| 410 |
if (sdl == NULL) |
| 411 |
return NULL; |
| 412 |
|
| 413 |
strcpy(sdl->bsdf.name, sdnam); |
| 414 |
sdl->next = SDcacheList; |
| 415 |
SDcacheList = sdl; |
| 416 |
|
| 417 |
sdl->refcnt = 1; |
| 418 |
return &sdl->bsdf; |
| 419 |
} |
| 420 |
|
| 421 |
/* Get loaded BSDF from cache (or load and cache it on first call) */ |
| 422 |
/* Report any problem to stderr and return NULL on failure */ |
| 423 |
const SDData * |
| 424 |
SDcacheFile(const char *fname) |
| 425 |
{ |
| 426 |
SDData *sd; |
| 427 |
SDError ec; |
| 428 |
|
| 429 |
if (fname == NULL || !*fname) |
| 430 |
return NULL; |
| 431 |
SDerrorDetail[0] = '\0'; |
| 432 |
/* PLACE MUTEX LOCK HERE FOR THREAD-SAFE */ |
| 433 |
if ((sd = SDgetCache(fname)) == NULL) { |
| 434 |
SDreportError(SDEmemory, stderr); |
| 435 |
return NULL; |
| 436 |
} |
| 437 |
if (!SDisLoaded(sd) && (ec = SDloadFile(sd, fname))) { |
| 438 |
SDreportError(ec, stderr); |
| 439 |
SDfreeCache(sd); |
| 440 |
sd = NULL; |
| 441 |
} |
| 442 |
/* END MUTEX LOCK */ |
| 443 |
return sd; |
| 444 |
} |
| 445 |
|
| 446 |
/* Free a BSDF from our cache (clear all if NULL) */ |
| 447 |
void |
| 448 |
SDfreeCache(const SDData *sd) |
| 449 |
{ |
| 450 |
struct SDCache_s *sdl, *sdLast = NULL; |
| 451 |
|
| 452 |
if (sd == NULL) { /* free entire list */ |
| 453 |
while ((sdl = SDcacheList) != NULL) { |
| 454 |
SDcacheList = sdl->next; |
| 455 |
SDfreeBSDF(&sdl->bsdf); |
| 456 |
free(sdl); |
| 457 |
} |
| 458 |
return; |
| 459 |
} |
| 460 |
for (sdl = SDcacheList; sdl != NULL; sdl = (sdLast=sdl)->next) |
| 461 |
if (&sdl->bsdf == sd) |
| 462 |
break; |
| 463 |
if (sdl == NULL || (sdl->refcnt -= (sdl->refcnt > 0))) |
| 464 |
return; /* missing or still in use */ |
| 465 |
/* keep unreferenced data? */ |
| 466 |
if (SDisLoaded(sd) && SDretainSet) { |
| 467 |
if (SDretainSet == SDretainAll) |
| 468 |
return; /* keep everything */ |
| 469 |
/* else free cumulative data */ |
| 470 |
SDfreeCumulativeCache(sd->rf); |
| 471 |
SDfreeCumulativeCache(sd->rb); |
| 472 |
SDfreeCumulativeCache(sd->tf); |
| 473 |
SDfreeCumulativeCache(sd->tb); |
| 474 |
return; |
| 475 |
} |
| 476 |
/* remove from list and free */ |
| 477 |
if (sdLast == NULL) |
| 478 |
SDcacheList = sdl->next; |
| 479 |
else |
| 480 |
sdLast->next = sdl->next; |
| 481 |
SDfreeBSDF(&sdl->bsdf); |
| 482 |
free(sdl); |
| 483 |
} |
| 484 |
|
| 485 |
/* Sample an individual BSDF component */ |
| 486 |
SDError |
| 487 |
SDsampComponent(SDValue *sv, FVECT ioVec, double randX, SDComponent *sdc) |
| 488 |
{ |
| 489 |
float coef[SDmaxCh]; |
| 490 |
SDError ec; |
| 491 |
FVECT inVec; |
| 492 |
const SDCDst *cd; |
| 493 |
double d; |
| 494 |
int n; |
| 495 |
/* check arguments */ |
| 496 |
if ((sv == NULL) | (ioVec == NULL) | (sdc == NULL)) |
| 497 |
return SDEargument; |
| 498 |
/* get cumulative distribution */ |
| 499 |
VCOPY(inVec, ioVec); |
| 500 |
sv->cieY = 0; |
| 501 |
cd = (*sdc->func->getCDist)(inVec, sdc); |
| 502 |
if (cd != NULL) |
| 503 |
sv->cieY = cd->cTotal; |
| 504 |
if (sv->cieY <= 1e-6) { /* nothing to sample? */ |
| 505 |
sv->spec = c_dfcolor; |
| 506 |
memset(ioVec, 0, sizeof(FVECT)); |
| 507 |
return SDEnone; |
| 508 |
} |
| 509 |
/* compute sample direction */ |
| 510 |
ec = (*sdc->func->sampCDist)(ioVec, randX, cd); |
| 511 |
if (ec) |
| 512 |
return ec; |
| 513 |
/* get BSDF color */ |
| 514 |
n = (*sdc->func->getBSDFs)(coef, inVec, ioVec, sdc); |
| 515 |
if (n <= 0) { |
| 516 |
strcpy(SDerrorDetail, "BSDF sample value error"); |
| 517 |
return SDEinternal; |
| 518 |
} |
| 519 |
sv->spec = sdc->cspec[0]; |
| 520 |
d = coef[0]; |
| 521 |
while (--n) { |
| 522 |
c_cmix(&sv->spec, d, &sv->spec, coef[n], &sdc->cspec[n]); |
| 523 |
d += coef[n]; |
| 524 |
} |
| 525 |
c_ccvt(&sv->spec, C_CSXY); /* make sure (x,y) is set */ |
| 526 |
return SDEnone; |
| 527 |
} |
| 528 |
|
| 529 |
#define MS_MAXDIM 15 |
| 530 |
|
| 531 |
/* Convert 1-dimensional random variable to N-dimensional */ |
| 532 |
void |
| 533 |
SDmultiSamp(RREAL t[], int n, double randX) |
| 534 |
{ |
| 535 |
unsigned nBits; |
| 536 |
double scale; |
| 537 |
bitmask_t ndx, coord[MS_MAXDIM]; |
| 538 |
|
| 539 |
if (n <= 0) /* check corner cases */ |
| 540 |
return; |
| 541 |
if (randX < 0) randX = 0; |
| 542 |
else if (randX >= 1.) randX = 0.999999999999999; |
| 543 |
if (n == 1) { |
| 544 |
t[0] = randX; |
| 545 |
return; |
| 546 |
} |
| 547 |
while (n > MS_MAXDIM) /* punt for higher dimensions */ |
| 548 |
t[--n] = rand()*(1./(RAND_MAX+.5)); |
| 549 |
nBits = (8*sizeof(bitmask_t) - 1) / n; |
| 550 |
ndx = randX * (double)((bitmask_t)1 << (nBits*n)); |
| 551 |
/* get coordinate on Hilbert curve */ |
| 552 |
hilbert_i2c(n, nBits, ndx, coord); |
| 553 |
/* convert back to [0,1) range */ |
| 554 |
scale = 1. / (double)((bitmask_t)1 << nBits); |
| 555 |
while (n--) |
| 556 |
t[n] = scale * ((double)coord[n] + rand()*(1./(RAND_MAX+.5))); |
| 557 |
} |
| 558 |
|
| 559 |
#undef MS_MAXDIM |
| 560 |
|
| 561 |
/* Generate diffuse hemispherical sample */ |
| 562 |
static void |
| 563 |
SDdiffuseSamp(FVECT ioVec, int outFront, double randX) |
| 564 |
{ |
| 565 |
/* convert to position on hemisphere */ |
| 566 |
SDmultiSamp(ioVec, 2, randX); |
| 567 |
square2disk(ioVec, ioVec[0], ioVec[1]); |
| 568 |
ioVec[2] = 1. - ioVec[0]*ioVec[0] - ioVec[1]*ioVec[1]; |
| 569 |
ioVec[2] = sqrt(ioVec[2]*(ioVec[2]>0)); |
| 570 |
if (!outFront) /* going out back? */ |
| 571 |
ioVec[2] = -ioVec[2]; |
| 572 |
} |
| 573 |
|
| 574 |
/* Query projected solid angle coverage for non-diffuse BSDF direction */ |
| 575 |
SDError |
| 576 |
SDsizeBSDF(double *projSA, const FVECT v1, const RREAL *v2, |
| 577 |
int qflags, const SDData *sd) |
| 578 |
{ |
| 579 |
SDSpectralDF *rdf, *tdf; |
| 580 |
SDError ec; |
| 581 |
int i; |
| 582 |
/* check arguments */ |
| 583 |
if ((projSA == NULL) | (v1 == NULL) | (sd == NULL)) |
| 584 |
return SDEargument; |
| 585 |
/* initialize extrema */ |
| 586 |
switch (qflags) { |
| 587 |
case SDqueryMax: |
| 588 |
projSA[0] = .0; |
| 589 |
break; |
| 590 |
case SDqueryMin+SDqueryMax: |
| 591 |
projSA[1] = .0; |
| 592 |
/* fall through */ |
| 593 |
case SDqueryMin: |
| 594 |
projSA[0] = 10.; |
| 595 |
break; |
| 596 |
case 0: |
| 597 |
return SDEargument; |
| 598 |
} |
| 599 |
if (v1[2] > 0) { /* front surface query? */ |
| 600 |
rdf = sd->rf; |
| 601 |
tdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
| 602 |
} else { |
| 603 |
rdf = sd->rb; |
| 604 |
tdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
| 605 |
} |
| 606 |
if (v2 != NULL) { /* bidirectional? */ |
| 607 |
if (v1[2] > 0 ^ v2[2] > 0) |
| 608 |
rdf = NULL; |
| 609 |
else |
| 610 |
tdf = NULL; |
| 611 |
} |
| 612 |
ec = SDEdata; /* run through components */ |
| 613 |
for (i = (rdf==NULL) ? 0 : rdf->ncomp; i--; ) { |
| 614 |
ec = (*rdf->comp[i].func->queryProjSA)(projSA, v1, v2, |
| 615 |
qflags, &rdf->comp[i]); |
| 616 |
if (ec) |
| 617 |
return ec; |
| 618 |
} |
| 619 |
for (i = (tdf==NULL) ? 0 : tdf->ncomp; i--; ) { |
| 620 |
ec = (*tdf->comp[i].func->queryProjSA)(projSA, v1, v2, |
| 621 |
qflags, &tdf->comp[i]); |
| 622 |
if (ec) |
| 623 |
return ec; |
| 624 |
} |
| 625 |
if (ec) { /* all diffuse? */ |
| 626 |
projSA[0] = M_PI; |
| 627 |
if (qflags == SDqueryMin+SDqueryMax) |
| 628 |
projSA[1] = M_PI; |
| 629 |
} else if (qflags == SDqueryMin+SDqueryMax && projSA[0] > projSA[1]) |
| 630 |
projSA[0] = projSA[1]; |
| 631 |
return SDEnone; |
| 632 |
} |
| 633 |
|
| 634 |
/* Return BSDF for the given incident and scattered ray vectors */ |
| 635 |
SDError |
| 636 |
SDevalBSDF(SDValue *sv, const FVECT inVec, const FVECT outVec, const SDData *sd) |
| 637 |
{ |
| 638 |
int inFront, outFront; |
| 639 |
SDSpectralDF *sdf; |
| 640 |
float coef[SDmaxCh]; |
| 641 |
int nch, i; |
| 642 |
/* check arguments */ |
| 643 |
if ((sv == NULL) | (outVec == NULL) | (inVec == NULL) | (sd == NULL)) |
| 644 |
return SDEargument; |
| 645 |
/* whose side are we on? */ |
| 646 |
inFront = (inVec[2] > 0); |
| 647 |
outFront = (outVec[2] > 0); |
| 648 |
/* start with diffuse portion */ |
| 649 |
if (inFront & outFront) { |
| 650 |
*sv = sd->rLambFront; |
| 651 |
sdf = sd->rf; |
| 652 |
} else if (!(inFront | outFront)) { |
| 653 |
*sv = sd->rLambBack; |
| 654 |
sdf = sd->rb; |
| 655 |
} else if (inFront) { |
| 656 |
*sv = sd->tLambFront; |
| 657 |
sdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
| 658 |
} else /* outFront & !inFront */ { |
| 659 |
*sv = sd->tLambBack; |
| 660 |
sdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
| 661 |
} |
| 662 |
sv->cieY *= 1./M_PI; |
| 663 |
/* add non-diffuse components */ |
| 664 |
i = (sdf != NULL) ? sdf->ncomp : 0; |
| 665 |
while (i-- > 0) { |
| 666 |
nch = (*sdf->comp[i].func->getBSDFs)(coef, inVec, outVec, |
| 667 |
&sdf->comp[i]); |
| 668 |
while (nch-- > 0) { |
| 669 |
c_cmix(&sv->spec, sv->cieY, &sv->spec, |
| 670 |
coef[nch], &sdf->comp[i].cspec[nch]); |
| 671 |
sv->cieY += coef[nch]; |
| 672 |
} |
| 673 |
} |
| 674 |
c_ccvt(&sv->spec, C_CSXY); /* make sure (x,y) is set */ |
| 675 |
return SDEnone; |
| 676 |
} |
| 677 |
|
| 678 |
/* Compute directional hemispherical scattering at this incident angle */ |
| 679 |
double |
| 680 |
SDdirectHemi(const FVECT inVec, int sflags, const SDData *sd) |
| 681 |
{ |
| 682 |
double hsum; |
| 683 |
SDSpectralDF *rdf, *tdf; |
| 684 |
const SDCDst *cd; |
| 685 |
int i; |
| 686 |
/* check arguments */ |
| 687 |
if ((inVec == NULL) | (sd == NULL)) |
| 688 |
return .0; |
| 689 |
/* gather diffuse components */ |
| 690 |
if (inVec[2] > 0) { |
| 691 |
hsum = sd->rLambFront.cieY; |
| 692 |
rdf = sd->rf; |
| 693 |
tdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
| 694 |
} else /* !inFront */ { |
| 695 |
hsum = sd->rLambBack.cieY; |
| 696 |
rdf = sd->rb; |
| 697 |
tdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
| 698 |
} |
| 699 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
| 700 |
hsum = .0; |
| 701 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
| 702 |
hsum += (inVec[2] > 0) ? |
| 703 |
sd->tLambFront.cieY : sd->tLambBack.cieY; |
| 704 |
/* gather non-diffuse components */ |
| 705 |
i = (((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR) & |
| 706 |
(rdf != NULL)) ? rdf->ncomp : 0; |
| 707 |
while (i-- > 0) { /* non-diffuse reflection */ |
| 708 |
cd = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
| 709 |
if (cd != NULL) |
| 710 |
hsum += cd->cTotal; |
| 711 |
} |
| 712 |
i = (((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT) & |
| 713 |
(tdf != NULL)) ? tdf->ncomp : 0; |
| 714 |
while (i-- > 0) { /* non-diffuse transmission */ |
| 715 |
cd = (*tdf->comp[i].func->getCDist)(inVec, &tdf->comp[i]); |
| 716 |
if (cd != NULL) |
| 717 |
hsum += cd->cTotal; |
| 718 |
} |
| 719 |
return hsum; |
| 720 |
} |
| 721 |
|
| 722 |
/* Sample BSDF direction based on the given random variable */ |
| 723 |
SDError |
| 724 |
SDsampBSDF(SDValue *sv, FVECT ioVec, double randX, int sflags, const SDData *sd) |
| 725 |
{ |
| 726 |
SDError ec; |
| 727 |
FVECT inVec; |
| 728 |
int inFront; |
| 729 |
SDSpectralDF *rdf, *tdf; |
| 730 |
double rdiff; |
| 731 |
float coef[SDmaxCh]; |
| 732 |
int i, j, n, nr; |
| 733 |
SDComponent *sdc; |
| 734 |
const SDCDst **cdarr = NULL; |
| 735 |
/* check arguments */ |
| 736 |
if ((sv == NULL) | (ioVec == NULL) | (sd == NULL) | |
| 737 |
(randX < 0) | (randX >= 1.)) |
| 738 |
return SDEargument; |
| 739 |
/* whose side are we on? */ |
| 740 |
VCOPY(inVec, ioVec); |
| 741 |
inFront = (inVec[2] > 0); |
| 742 |
/* remember diffuse portions */ |
| 743 |
if (inFront) { |
| 744 |
*sv = sd->rLambFront; |
| 745 |
rdf = sd->rf; |
| 746 |
tdf = (sd->tf != NULL) ? sd->tf : sd->tb; |
| 747 |
} else /* !inFront */ { |
| 748 |
*sv = sd->rLambBack; |
| 749 |
rdf = sd->rb; |
| 750 |
tdf = (sd->tb != NULL) ? sd->tb : sd->tf; |
| 751 |
} |
| 752 |
if ((sflags & SDsampDf+SDsampR) != SDsampDf+SDsampR) |
| 753 |
sv->cieY = .0; |
| 754 |
rdiff = sv->cieY; |
| 755 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) |
| 756 |
sv->cieY += inFront ? sd->tLambFront.cieY : sd->tLambBack.cieY; |
| 757 |
/* gather non-diffuse components */ |
| 758 |
i = nr = (((sflags & SDsampSp+SDsampR) == SDsampSp+SDsampR) & |
| 759 |
(rdf != NULL)) ? rdf->ncomp : 0; |
| 760 |
j = (((sflags & SDsampSp+SDsampT) == SDsampSp+SDsampT) & |
| 761 |
(tdf != NULL)) ? tdf->ncomp : 0; |
| 762 |
n = i + j; |
| 763 |
if (n > 0 && (cdarr = (const SDCDst **)malloc(n*sizeof(SDCDst *))) == NULL) |
| 764 |
return SDEmemory; |
| 765 |
while (j-- > 0) { /* non-diffuse transmission */ |
| 766 |
cdarr[i+j] = (*tdf->comp[j].func->getCDist)(inVec, &tdf->comp[j]); |
| 767 |
if (cdarr[i+j] == NULL) |
| 768 |
cdarr[i+j] = &SDemptyCD; |
| 769 |
sv->cieY += cdarr[i+j]->cTotal; |
| 770 |
} |
| 771 |
while (i-- > 0) { /* non-diffuse reflection */ |
| 772 |
cdarr[i] = (*rdf->comp[i].func->getCDist)(inVec, &rdf->comp[i]); |
| 773 |
if (cdarr[i] == NULL) |
| 774 |
cdarr[i] = &SDemptyCD; |
| 775 |
sv->cieY += cdarr[i]->cTotal; |
| 776 |
} |
| 777 |
if (sv->cieY <= 1e-6) { /* anything to sample? */ |
| 778 |
sv->cieY = .0; |
| 779 |
memset(ioVec, 0, sizeof(FVECT)); |
| 780 |
return SDEnone; |
| 781 |
} |
| 782 |
/* scale random variable */ |
| 783 |
randX *= sv->cieY; |
| 784 |
/* diffuse reflection? */ |
| 785 |
if (randX < rdiff) { |
| 786 |
SDdiffuseSamp(ioVec, inFront, randX/rdiff); |
| 787 |
goto done; |
| 788 |
} |
| 789 |
randX -= rdiff; |
| 790 |
/* diffuse transmission? */ |
| 791 |
if ((sflags & SDsampDf+SDsampT) == SDsampDf+SDsampT) { |
| 792 |
const SDValue *sdt = inFront ? &sd->tLambFront : &sd->tLambBack; |
| 793 |
if (randX < sdt->cieY) { |
| 794 |
sv->spec = sdt->spec; |
| 795 |
SDdiffuseSamp(ioVec, !inFront, randX/sdt->cieY); |
| 796 |
goto done; |
| 797 |
} |
| 798 |
randX -= sdt->cieY; |
| 799 |
} |
| 800 |
/* else one of cumulative dist. */ |
| 801 |
for (i = 0; i < n && randX >= cdarr[i]->cTotal; i++) |
| 802 |
randX -= cdarr[i]->cTotal; |
| 803 |
if (i >= n) |
| 804 |
return SDEinternal; |
| 805 |
/* compute sample direction */ |
| 806 |
sdc = (i < nr) ? &rdf->comp[i] : &tdf->comp[i-nr]; |
| 807 |
ec = (*sdc->func->sampCDist)(ioVec, randX/cdarr[i]->cTotal, cdarr[i]); |
| 808 |
if (ec) |
| 809 |
return ec; |
| 810 |
/* compute color */ |
| 811 |
j = (*sdc->func->getBSDFs)(coef, inVec, ioVec, sdc); |
| 812 |
if (j <= 0) { |
| 813 |
sprintf(SDerrorDetail, "BSDF \"%s\" sampling value error", |
| 814 |
sd->name); |
| 815 |
return SDEinternal; |
| 816 |
} |
| 817 |
sv->spec = sdc->cspec[0]; |
| 818 |
rdiff = coef[0]; |
| 819 |
while (--j) { |
| 820 |
c_cmix(&sv->spec, rdiff, &sv->spec, coef[j], &sdc->cspec[j]); |
| 821 |
rdiff += coef[j]; |
| 822 |
} |
| 823 |
done: |
| 824 |
if (cdarr != NULL) |
| 825 |
free(cdarr); |
| 826 |
c_ccvt(&sv->spec, C_CSXY); /* make sure (x,y) is set */ |
| 827 |
return SDEnone; |
| 828 |
} |
| 829 |
|
| 830 |
/* Compute World->BSDF transform from surface normal and up (Y) vector */ |
| 831 |
SDError |
| 832 |
SDcompXform(RREAL vMtx[3][3], const FVECT sNrm, const FVECT uVec) |
| 833 |
{ |
| 834 |
if ((vMtx == NULL) | (sNrm == NULL) | (uVec == NULL)) |
| 835 |
return SDEargument; |
| 836 |
VCOPY(vMtx[2], sNrm); |
| 837 |
if (normalize(vMtx[2]) == 0) |
| 838 |
return SDEargument; |
| 839 |
fcross(vMtx[0], uVec, vMtx[2]); |
| 840 |
if (normalize(vMtx[0]) == 0) |
| 841 |
return SDEargument; |
| 842 |
fcross(vMtx[1], vMtx[2], vMtx[0]); |
| 843 |
return SDEnone; |
| 844 |
} |
| 845 |
|
| 846 |
/* Compute inverse transform */ |
| 847 |
SDError |
| 848 |
SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]) |
| 849 |
{ |
| 850 |
RREAL mTmp[3][3]; |
| 851 |
double d; |
| 852 |
|
| 853 |
if ((iMtx == NULL) | (vMtx == NULL)) |
| 854 |
return SDEargument; |
| 855 |
/* compute determinant */ |
| 856 |
mTmp[0][0] = vMtx[2][2]*vMtx[1][1] - vMtx[2][1]*vMtx[1][2]; |
| 857 |
mTmp[0][1] = vMtx[2][1]*vMtx[0][2] - vMtx[2][2]*vMtx[0][1]; |
| 858 |
mTmp[0][2] = vMtx[1][2]*vMtx[0][1] - vMtx[1][1]*vMtx[0][2]; |
| 859 |
d = vMtx[0][0]*mTmp[0][0] + vMtx[1][0]*mTmp[0][1] + vMtx[2][0]*mTmp[0][2]; |
| 860 |
if (d == 0) { |
| 861 |
strcpy(SDerrorDetail, "Zero determinant in matrix inversion"); |
| 862 |
return SDEargument; |
| 863 |
} |
| 864 |
d = 1./d; /* invert matrix */ |
| 865 |
mTmp[0][0] *= d; mTmp[0][1] *= d; mTmp[0][2] *= d; |
| 866 |
mTmp[1][0] = d*(vMtx[2][0]*vMtx[1][2] - vMtx[2][2]*vMtx[1][0]); |
| 867 |
mTmp[1][1] = d*(vMtx[2][2]*vMtx[0][0] - vMtx[2][0]*vMtx[0][2]); |
| 868 |
mTmp[1][2] = d*(vMtx[1][0]*vMtx[0][2] - vMtx[1][2]*vMtx[0][0]); |
| 869 |
mTmp[2][0] = d*(vMtx[2][1]*vMtx[1][0] - vMtx[2][0]*vMtx[1][1]); |
| 870 |
mTmp[2][1] = d*(vMtx[2][0]*vMtx[0][1] - vMtx[2][1]*vMtx[0][0]); |
| 871 |
mTmp[2][2] = d*(vMtx[1][1]*vMtx[0][0] - vMtx[1][0]*vMtx[0][1]); |
| 872 |
memcpy(iMtx, mTmp, sizeof(mTmp)); |
| 873 |
return SDEnone; |
| 874 |
} |
| 875 |
|
| 876 |
/* Transform and normalize direction (column) vector */ |
| 877 |
SDError |
| 878 |
SDmapDir(FVECT resVec, RREAL vMtx[3][3], const FVECT inpVec) |
| 879 |
{ |
| 880 |
FVECT vTmp; |
| 881 |
|
| 882 |
if ((resVec == NULL) | (inpVec == NULL)) |
| 883 |
return SDEargument; |
| 884 |
if (vMtx == NULL) { /* assume they just want to normalize */ |
| 885 |
if (resVec != inpVec) |
| 886 |
VCOPY(resVec, inpVec); |
| 887 |
return (normalize(resVec) > 0) ? SDEnone : SDEargument; |
| 888 |
} |
| 889 |
vTmp[0] = DOT(vMtx[0], inpVec); |
| 890 |
vTmp[1] = DOT(vMtx[1], inpVec); |
| 891 |
vTmp[2] = DOT(vMtx[2], inpVec); |
| 892 |
if (normalize(vTmp) == 0) |
| 893 |
return SDEargument; |
| 894 |
VCOPY(resVec, vTmp); |
| 895 |
return SDEnone; |
| 896 |
} |
