| 1 |
/* Copyright (c) 1990 Regents of the University of California */ |
| 2 |
|
| 3 |
#ifndef lint |
| 4 |
static char SCCSid[] = "$SunId$ LBL"; |
| 5 |
#endif |
| 6 |
|
| 7 |
/* |
| 8 |
* source.c - routines dealing with illumination sources. |
| 9 |
* |
| 10 |
* 8/20/85 |
| 11 |
*/ |
| 12 |
|
| 13 |
#include "ray.h" |
| 14 |
|
| 15 |
#include "octree.h" |
| 16 |
|
| 17 |
#include "source.h" |
| 18 |
|
| 19 |
#include "otypes.h" |
| 20 |
|
| 21 |
#include "cone.h" |
| 22 |
|
| 23 |
#include "face.h" |
| 24 |
|
| 25 |
#include "random.h" |
| 26 |
|
| 27 |
|
| 28 |
extern double dstrsrc; /* source distribution amount */ |
| 29 |
extern double shadthresh; /* relative shadow threshold */ |
| 30 |
extern double shadcert; /* shadow testing certainty */ |
| 31 |
|
| 32 |
SRCREC *source = NULL; /* our list of sources */ |
| 33 |
int nsources = 0; /* the number of sources */ |
| 34 |
|
| 35 |
static CONTRIB *srccnt; /* source contributions in direct() */ |
| 36 |
static CNTPTR *cntord; /* source ordering in direct() */ |
| 37 |
|
| 38 |
|
| 39 |
marksources() /* find and mark source objects */ |
| 40 |
{ |
| 41 |
register OBJREC *o, *m; |
| 42 |
register int i; |
| 43 |
|
| 44 |
for (i = 0; i < nobjects; i++) { |
| 45 |
|
| 46 |
o = objptr(i); |
| 47 |
|
| 48 |
if (o->omod == OVOID) |
| 49 |
continue; |
| 50 |
|
| 51 |
m = objptr(o->omod); |
| 52 |
|
| 53 |
if (!islight(m->otype)) |
| 54 |
continue; |
| 55 |
|
| 56 |
if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 : |
| 57 |
m->otype == MAT_SPOT ? 7 : 3)) |
| 58 |
objerror(m, USER, "bad # arguments"); |
| 59 |
|
| 60 |
if (m->otype == MAT_GLOW && |
| 61 |
o->otype != OBJ_SOURCE && |
| 62 |
m->oargs.farg[3] <= FTINY) |
| 63 |
continue; /* don't bother */ |
| 64 |
|
| 65 |
if (source == NULL) |
| 66 |
source = (SRCREC *)malloc(sizeof(SRCREC)); |
| 67 |
else |
| 68 |
source = (SRCREC *)realloc((char *)source, |
| 69 |
(unsigned)(nsources+1)*sizeof(SRCREC)); |
| 70 |
if (source == NULL) |
| 71 |
goto memerr; |
| 72 |
|
| 73 |
newsource(&source[nsources], o); |
| 74 |
|
| 75 |
if (m->otype == MAT_GLOW) { |
| 76 |
source[nsources].sflags |= SPROX; |
| 77 |
source[nsources].sl.prox = m->oargs.farg[3]; |
| 78 |
if (o->otype == OBJ_SOURCE) |
| 79 |
source[nsources].sflags |= SSKIP; |
| 80 |
} else if (m->otype == MAT_SPOT) { |
| 81 |
source[nsources].sflags |= SSPOT; |
| 82 |
source[nsources].sl.s = makespot(m); |
| 83 |
} |
| 84 |
nsources++; |
| 85 |
} |
| 86 |
if (nsources <= 0) { |
| 87 |
error(WARNING, "no light sources found"); |
| 88 |
return; |
| 89 |
} |
| 90 |
srccnt = (CONTRIB *)malloc(nsources*sizeof(CONTRIB)); |
| 91 |
cntord = (CNTPTR *)malloc(nsources*sizeof(CNTPTR)); |
| 92 |
if (srccnt != NULL && cntord != NULL) |
| 93 |
return; |
| 94 |
/* fall through */ |
| 95 |
memerr: |
| 96 |
error(SYSTEM, "out of memory in marksources"); |
| 97 |
} |
| 98 |
|
| 99 |
|
| 100 |
newsource(src, so) /* add a source to the array */ |
| 101 |
register SRCREC *src; |
| 102 |
register OBJREC *so; |
| 103 |
{ |
| 104 |
double cos(), tan(), sqrt(); |
| 105 |
double theta; |
| 106 |
FACE *f; |
| 107 |
CONE *co; |
| 108 |
int j; |
| 109 |
register int i; |
| 110 |
|
| 111 |
src->sflags = 0; |
| 112 |
src->nhits = 1; src->ntests = 2; /* start probability = 1/2 */ |
| 113 |
src->so = so; |
| 114 |
|
| 115 |
switch (so->otype) { |
| 116 |
case OBJ_SOURCE: |
| 117 |
if (so->oargs.nfargs != 4) |
| 118 |
objerror(so, USER, "bad arguments"); |
| 119 |
src->sflags |= SDISTANT; |
| 120 |
VCOPY(src->sloc, so->oargs.farg); |
| 121 |
if (normalize(src->sloc) == 0.0) |
| 122 |
objerror(so, USER, "zero direction"); |
| 123 |
theta = PI/180.0/2.0 * so->oargs.farg[3]; |
| 124 |
if (theta <= FTINY) |
| 125 |
objerror(so, USER, "zero size"); |
| 126 |
src->ss = theta >= PI/4 ? 1.0 : tan(theta); |
| 127 |
src->ss2 = 2.0*PI * (1.0 - cos(theta)); |
| 128 |
break; |
| 129 |
case OBJ_SPHERE: |
| 130 |
VCOPY(src->sloc, so->oargs.farg); |
| 131 |
src->ss = so->oargs.farg[3]; |
| 132 |
src->ss2 = PI * src->ss * src->ss; |
| 133 |
break; |
| 134 |
case OBJ_FACE: |
| 135 |
/* get the face */ |
| 136 |
f = getface(so); |
| 137 |
/* find the center */ |
| 138 |
for (j = 0; j < 3; j++) { |
| 139 |
src->sloc[j] = 0.0; |
| 140 |
for (i = 0; i < f->nv; i++) |
| 141 |
src->sloc[j] += VERTEX(f,i)[j]; |
| 142 |
src->sloc[j] /= f->nv; |
| 143 |
} |
| 144 |
if (!inface(src->sloc, f)) |
| 145 |
objerror(so, USER, "cannot hit center"); |
| 146 |
src->ss = sqrt(f->area / PI); |
| 147 |
src->ss2 = f->area; |
| 148 |
break; |
| 149 |
case OBJ_RING: |
| 150 |
/* get the ring */ |
| 151 |
co = getcone(so, 0); |
| 152 |
VCOPY(src->sloc, CO_P0(co)); |
| 153 |
if (CO_R0(co) > 0.0) |
| 154 |
objerror(so, USER, "cannot hit center"); |
| 155 |
src->ss = CO_R1(co); |
| 156 |
src->ss2 = PI * src->ss * src->ss; |
| 157 |
break; |
| 158 |
default: |
| 159 |
objerror(so, USER, "illegal material"); |
| 160 |
} |
| 161 |
} |
| 162 |
|
| 163 |
|
| 164 |
SPOT * |
| 165 |
makespot(m) /* make a spotlight */ |
| 166 |
register OBJREC *m; |
| 167 |
{ |
| 168 |
extern double cos(); |
| 169 |
register SPOT *ns; |
| 170 |
|
| 171 |
if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
| 172 |
error(SYSTEM, "out of memory in makespot"); |
| 173 |
ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3])); |
| 174 |
VCOPY(ns->aim, m->oargs.farg+4); |
| 175 |
if ((ns->flen = normalize(ns->aim)) == 0.0) |
| 176 |
objerror(m, USER, "zero focus vector"); |
| 177 |
return(ns); |
| 178 |
} |
| 179 |
|
| 180 |
|
| 181 |
double |
| 182 |
srcray(sr, r, sn) /* send a ray to a source, return domega */ |
| 183 |
register RAY *sr; /* returned source ray */ |
| 184 |
RAY *r; /* ray which hit object */ |
| 185 |
register int sn; /* source number */ |
| 186 |
{ |
| 187 |
register double *norm = NULL; /* plane normal */ |
| 188 |
double ddot; /* (distance times) cosine */ |
| 189 |
FVECT vd; |
| 190 |
double d; |
| 191 |
register int i; |
| 192 |
|
| 193 |
if (source[sn].sflags & SSKIP) |
| 194 |
return(0.0); /* skip this source */ |
| 195 |
|
| 196 |
rayorigin(sr, r, SHADOW, 1.0); /* ignore limits */ |
| 197 |
|
| 198 |
sr->rsrc = sn; /* remember source */ |
| 199 |
/* get source direction */ |
| 200 |
if (source[sn].sflags & SDISTANT) |
| 201 |
/* constant direction */ |
| 202 |
VCOPY(sr->rdir, source[sn].sloc); |
| 203 |
else { /* compute direction */ |
| 204 |
for (i = 0; i < 3; i++) |
| 205 |
sr->rdir[i] = source[sn].sloc[i] - sr->rorg[i]; |
| 206 |
|
| 207 |
if (source[sn].so->otype == OBJ_FACE) |
| 208 |
norm = getface(source[sn].so)->norm; |
| 209 |
else if (source[sn].so->otype == OBJ_RING) |
| 210 |
norm = getcone(source[sn].so,0)->ad; |
| 211 |
|
| 212 |
if (norm != NULL && (ddot = -DOT(sr->rdir, norm)) <= FTINY) |
| 213 |
return(0.0); /* behind surface! */ |
| 214 |
} |
| 215 |
if (dstrsrc > FTINY) { |
| 216 |
/* distribute source direction */ |
| 217 |
for (i = 0; i < 3; i++) |
| 218 |
vd[i] = dstrsrc * source[sn].ss * (1.0 - 2.0*frandom()); |
| 219 |
|
| 220 |
if (norm != NULL) { /* project offset */ |
| 221 |
d = DOT(vd, norm); |
| 222 |
for (i = 0; i < 3; i++) |
| 223 |
vd[i] -= d * norm[i]; |
| 224 |
} |
| 225 |
for (i = 0; i < 3; i++) /* offset source direction */ |
| 226 |
sr->rdir[i] += vd[i]; |
| 227 |
|
| 228 |
} else if (source[sn].sflags & SDISTANT) |
| 229 |
/* already normalized */ |
| 230 |
return(source[sn].ss2); |
| 231 |
|
| 232 |
if ((d = normalize(sr->rdir)) == 0.0) |
| 233 |
/* at source! */ |
| 234 |
return(0.0); |
| 235 |
|
| 236 |
if (source[sn].sflags & SDISTANT) |
| 237 |
/* domega constant */ |
| 238 |
return(source[sn].ss2); |
| 239 |
|
| 240 |
else { |
| 241 |
/* check proximity */ |
| 242 |
if (source[sn].sflags & SPROX && |
| 243 |
d > source[sn].sl.prox) |
| 244 |
return(0.0); |
| 245 |
|
| 246 |
if (norm != NULL) |
| 247 |
ddot /= d; |
| 248 |
else |
| 249 |
ddot = 1.0; |
| 250 |
/* check angle */ |
| 251 |
if (source[sn].sflags & SSPOT) { |
| 252 |
if (source[sn].sl.s->siz < 2.0*PI * |
| 253 |
(1.0 + DOT(source[sn].sl.s->aim,sr->rdir))) |
| 254 |
return(0.0); |
| 255 |
d += source[sn].sl.s->flen; |
| 256 |
} |
| 257 |
/* return domega */ |
| 258 |
return(ddot*source[sn].ss2/(d*d)); |
| 259 |
} |
| 260 |
} |
| 261 |
|
| 262 |
|
| 263 |
sourcehit(r) /* check to see if ray hit distant source */ |
| 264 |
register RAY *r; |
| 265 |
{ |
| 266 |
int first, last; |
| 267 |
register int i; |
| 268 |
|
| 269 |
if (r->rsrc >= 0) { /* check only one if aimed */ |
| 270 |
first = last = r->rsrc; |
| 271 |
} else { /* otherwise check all */ |
| 272 |
first = 0; last = nsources-1; |
| 273 |
} |
| 274 |
for (i = first; i <= last; i++) |
| 275 |
if (source[i].sflags & SDISTANT) |
| 276 |
/* |
| 277 |
* Check to see if ray is within |
| 278 |
* solid angle of source. |
| 279 |
*/ |
| 280 |
if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir)) |
| 281 |
<= source[i].ss2) { |
| 282 |
r->ro = source[i].so; |
| 283 |
if (!(source[i].sflags & SSKIP)) |
| 284 |
break; |
| 285 |
} |
| 286 |
|
| 287 |
if (r->ro != NULL) { |
| 288 |
for (i = 0; i < 3; i++) |
| 289 |
r->ron[i] = -r->rdir[i]; |
| 290 |
r->rod = 1.0; |
| 291 |
r->rofs = 1.0; setident4(r->rofx); |
| 292 |
r->robs = 1.0; setident4(r->robx); |
| 293 |
return(1); |
| 294 |
} |
| 295 |
return(0); |
| 296 |
} |
| 297 |
|
| 298 |
|
| 299 |
static int |
| 300 |
cntcmp(sc1, sc2) /* contribution compare (descending) */ |
| 301 |
register CNTPTR *sc1, *sc2; |
| 302 |
{ |
| 303 |
if (sc1->brt > sc2->brt) |
| 304 |
return(-1); |
| 305 |
if (sc1->brt < sc2->brt) |
| 306 |
return(1); |
| 307 |
return(0); |
| 308 |
} |
| 309 |
|
| 310 |
|
| 311 |
direct(r, f, p) /* add direct component */ |
| 312 |
RAY *r; /* ray that hit surface */ |
| 313 |
int (*f)(); /* direct component coefficient function */ |
| 314 |
char *p; /* data for f */ |
| 315 |
{ |
| 316 |
extern double pow(); |
| 317 |
register int sn; |
| 318 |
int nshadcheck, ncnts; |
| 319 |
double prob, ourthresh, hwt, test2, hit2; |
| 320 |
RAY sr; |
| 321 |
/* NOTE: srccnt and cntord global so no recursion */ |
| 322 |
if (nsources <= 0) |
| 323 |
return; /* no sources?! */ |
| 324 |
/* compute number to check */ |
| 325 |
nshadcheck = pow((double)nsources, shadcert) + .5; |
| 326 |
/* modify threshold */ |
| 327 |
ourthresh = shadthresh / r->rweight; |
| 328 |
/* potential contributions */ |
| 329 |
for (sn = 0; sn < nsources; sn++) { |
| 330 |
cntord[sn].sno = sn; |
| 331 |
cntord[sn].brt = 0.0; |
| 332 |
/* get source ray */ |
| 333 |
if ((srccnt[sn].dom = srcray(&sr, r, sn)) == 0.0) |
| 334 |
continue; |
| 335 |
VCOPY(srccnt[sn].dir, sr.rdir); |
| 336 |
/* compute coefficient */ |
| 337 |
(*f)(srccnt[sn].val, p, srccnt[sn].dir, srccnt[sn].dom); |
| 338 |
cntord[sn].brt = bright(srccnt[sn].val); |
| 339 |
if (cntord[sn].brt <= 0.0) |
| 340 |
continue; |
| 341 |
/* compute intersection */ |
| 342 |
if (!( source[sn].sflags & SDISTANT ? |
| 343 |
sourcehit(&sr) : |
| 344 |
(*ofun[source[sn].so->otype].funp) |
| 345 |
(source[sn].so, &sr) )) { |
| 346 |
sprintf(errmsg, |
| 347 |
"aiming failure for light source \"%s\"", |
| 348 |
source[sn].so->oname); |
| 349 |
error(WARNING, errmsg); |
| 350 |
continue; |
| 351 |
} |
| 352 |
/* compute contribution */ |
| 353 |
raycont(&sr); |
| 354 |
multcolor(srccnt[sn].val, sr.rcol); |
| 355 |
cntord[sn].brt = bright(srccnt[sn].val); |
| 356 |
} |
| 357 |
/* sort contributions */ |
| 358 |
qsort(cntord, nsources, sizeof(CNTPTR), cntcmp); |
| 359 |
{ /* find last */ |
| 360 |
register int l, m; |
| 361 |
|
| 362 |
sn = 0; ncnts = l = nsources; |
| 363 |
while ((m = (sn + ncnts) >> 1) != l) { |
| 364 |
if (cntord[m].brt > 0.0) |
| 365 |
sn = m; |
| 366 |
else |
| 367 |
ncnts = m; |
| 368 |
l = m; |
| 369 |
} |
| 370 |
} |
| 371 |
/* accumulate tail */ |
| 372 |
for (sn = ncnts-1; sn > 0; sn--) |
| 373 |
cntord[sn-1].brt += cntord[sn].brt; |
| 374 |
/* start with prob=.5 */ |
| 375 |
hit2 = 0.5; test2 = 1.0; |
| 376 |
/* test for shadows */ |
| 377 |
for (sn = 0; sn < ncnts; sn++) { |
| 378 |
/* check threshold */ |
| 379 |
if ((sn+nshadcheck>=ncnts ? cntord[sn].brt : |
| 380 |
cntord[sn].brt-cntord[sn+nshadcheck].brt) < |
| 381 |
ourthresh*bright(r->rcol)) |
| 382 |
break; |
| 383 |
/* get statistics */ |
| 384 |
hwt = (double)source[cntord[sn].sno].nhits / |
| 385 |
(double)source[cntord[sn].sno].ntests; |
| 386 |
test2 += hwt; |
| 387 |
source[cntord[sn].sno].ntests++; |
| 388 |
/* test for hit */ |
| 389 |
rayorigin(&sr, r, SHADOW, 1.0); |
| 390 |
VCOPY(sr.rdir, srccnt[cntord[sn].sno].dir); |
| 391 |
sr.rsrc = cntord[sn].sno; |
| 392 |
if (localhit(&sr, &thescene) && |
| 393 |
sr.ro != source[cntord[sn].sno].so) { |
| 394 |
/* check for transmission */ |
| 395 |
raycont(&sr); |
| 396 |
if (bright(sr.rcol) <= FTINY) |
| 397 |
continue; /* missed! */ |
| 398 |
(*f)(srccnt[cntord[sn].sno].val, p, |
| 399 |
srccnt[cntord[sn].sno].dir, |
| 400 |
srccnt[cntord[sn].sno].dom); |
| 401 |
multcolor(srccnt[cntord[sn].sno].val, sr.rcol); |
| 402 |
} |
| 403 |
/* add contribution if hit */ |
| 404 |
addcolor(r->rcol, srccnt[cntord[sn].sno].val); |
| 405 |
hit2 += hwt; |
| 406 |
source[cntord[sn].sno].nhits++; |
| 407 |
} |
| 408 |
/* weighted hit rate */ |
| 409 |
hwt = hit2 / test2; |
| 410 |
#ifdef DEBUG |
| 411 |
sprintf(errmsg, "%d tested, %d untested, %f hit rate\n", |
| 412 |
sn, ncnts-sn, hwt); |
| 413 |
eputs(errmsg); |
| 414 |
#endif |
| 415 |
/* add in untested sources */ |
| 416 |
for ( ; sn < ncnts; sn++) { |
| 417 |
prob = hwt * (double)source[cntord[sn].sno].nhits / |
| 418 |
(double)source[cntord[sn].sno].ntests; |
| 419 |
scalecolor(srccnt[cntord[sn].sno].val, prob); |
| 420 |
addcolor(r->rcol, srccnt[cntord[sn].sno].val); |
| 421 |
} |
| 422 |
} |
| 423 |
|
| 424 |
|
| 425 |
#define wrongsource(m, r) (m->otype!=MAT_ILLUM && \ |
| 426 |
r->rsrc>=0 && \ |
| 427 |
source[r->rsrc].so!=r->ro) |
| 428 |
|
| 429 |
#define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \ |
| 430 |
!(r->rtype&REFLECTED) && /* hack! */\ |
| 431 |
!(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3])) |
| 432 |
|
| 433 |
#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
| 434 |
!(r->rsrc>=0&&source[r->rsrc].so==r->ro)) |
| 435 |
|
| 436 |
|
| 437 |
m_light(m, r) /* ray hit a light source */ |
| 438 |
register OBJREC *m; |
| 439 |
register RAY *r; |
| 440 |
{ |
| 441 |
/* check for over-counting */ |
| 442 |
if (wrongsource(m, r) || badambient(m, r)) |
| 443 |
return; |
| 444 |
/* check for passed illum */ |
| 445 |
if (passillum(m, r)) { |
| 446 |
|
| 447 |
if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID)) |
| 448 |
raytrans(r); |
| 449 |
else |
| 450 |
rayshade(r, modifier(m->oargs.sarg[0])); |
| 451 |
|
| 452 |
/* otherwise treat as source */ |
| 453 |
} else { |
| 454 |
/* check for behind */ |
| 455 |
if (r->rod < 0.0) |
| 456 |
return; |
| 457 |
/* get distribution pattern */ |
| 458 |
raytexture(r, m->omod); |
| 459 |
/* get source color */ |
| 460 |
setcolor(r->rcol, m->oargs.farg[0], |
| 461 |
m->oargs.farg[1], |
| 462 |
m->oargs.farg[2]); |
| 463 |
/* modify value */ |
| 464 |
multcolor(r->rcol, r->pcol); |
| 465 |
/* assign distance */ |
| 466 |
r->rt = r->rot; |
| 467 |
} |
| 468 |
} |
