1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: source.c,v 2.58 2010/08/23 15:56:17 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* source.c - routines dealing with illumination sources. |
6 |
* |
7 |
* External symbols declared in source.h |
8 |
*/ |
9 |
|
10 |
#include "ray.h" |
11 |
#include "otypes.h" |
12 |
#include "rtotypes.h" |
13 |
#include "source.h" |
14 |
#include "random.h" |
15 |
|
16 |
extern double ssampdist; /* scatter sampling distance */ |
17 |
|
18 |
#ifndef MAXSSAMP |
19 |
#define MAXSSAMP 16 /* maximum samples per ray */ |
20 |
#endif |
21 |
|
22 |
/* |
23 |
* Structures used by direct() |
24 |
*/ |
25 |
|
26 |
typedef struct { |
27 |
int sno; /* source number */ |
28 |
FVECT dir; /* source direction */ |
29 |
COLOR coef; /* material coefficient */ |
30 |
COLOR val; /* contribution */ |
31 |
} CONTRIB; /* direct contribution */ |
32 |
|
33 |
typedef struct { |
34 |
int sndx; /* source index (to CONTRIB array) */ |
35 |
float brt; /* brightness (for comparison) */ |
36 |
} CNTPTR; /* contribution pointer */ |
37 |
|
38 |
static CONTRIB *srccnt; /* source contributions in direct() */ |
39 |
static CNTPTR *cntord; /* source ordering in direct() */ |
40 |
static int maxcntr = 0; /* size of contribution arrays */ |
41 |
|
42 |
static int cntcmp(const void *p1, const void *p2); |
43 |
|
44 |
|
45 |
extern OBJREC * /* find an object's actual material */ |
46 |
findmaterial(register OBJREC *o) |
47 |
{ |
48 |
while (!ismaterial(o->otype)) { |
49 |
if (o->otype == MOD_ALIAS && o->oargs.nsargs) { |
50 |
OBJECT aobj; |
51 |
OBJREC *ao; |
52 |
aobj = lastmod(objndx(o), o->oargs.sarg[0]); |
53 |
if (aobj < 0) |
54 |
objerror(o, USER, "bad reference"); |
55 |
ao = objptr(aobj); |
56 |
if (ismaterial(ao->otype)) |
57 |
return(ao); |
58 |
if (ao->otype == MOD_ALIAS) { |
59 |
o = ao; |
60 |
continue; |
61 |
} |
62 |
} |
63 |
if (o->omod == OVOID) |
64 |
return(NULL); |
65 |
o = objptr(o->omod); |
66 |
} |
67 |
return(o); /* mixtures will return NULL */ |
68 |
} |
69 |
|
70 |
|
71 |
extern void |
72 |
marksources(void) /* find and mark source objects */ |
73 |
{ |
74 |
int foundsource = 0; |
75 |
int i; |
76 |
register OBJREC *o, *m; |
77 |
register int ns; |
78 |
/* initialize dispatch table */ |
79 |
initstypes(); |
80 |
/* find direct sources */ |
81 |
for (i = 0; i < nsceneobjs; i++) { |
82 |
|
83 |
o = objptr(i); |
84 |
|
85 |
if (!issurface(o->otype) || o->omod == OVOID) |
86 |
continue; |
87 |
/* find material */ |
88 |
m = findmaterial(objptr(o->omod)); |
89 |
if (m == NULL) |
90 |
continue; |
91 |
if (m->otype == MAT_CLIP) { |
92 |
markclip(m); /* special case for antimatter */ |
93 |
continue; |
94 |
} |
95 |
if (!islight(m->otype)) |
96 |
continue; /* not source modifier */ |
97 |
|
98 |
if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 : |
99 |
m->otype == MAT_SPOT ? 7 : 3)) |
100 |
objerror(m, USER, "bad # arguments"); |
101 |
|
102 |
if (m->otype == MAT_GLOW && |
103 |
o->otype != OBJ_SOURCE && |
104 |
m->oargs.farg[3] <= FTINY) |
105 |
continue; /* don't bother */ |
106 |
if (m->oargs.farg[0] <= FTINY && m->oargs.farg[1] <= FTINY && |
107 |
m->oargs.farg[2] <= FTINY) |
108 |
continue; /* don't bother */ |
109 |
|
110 |
if (sfun[o->otype].of == NULL || |
111 |
sfun[o->otype].of->setsrc == NULL) |
112 |
objerror(o, USER, "illegal material"); |
113 |
|
114 |
if ((ns = newsource()) < 0) |
115 |
goto memerr; |
116 |
|
117 |
setsource(&source[ns], o); |
118 |
|
119 |
if (m->otype == MAT_GLOW) { |
120 |
source[ns].sflags |= SPROX; |
121 |
source[ns].sl.prox = m->oargs.farg[3]; |
122 |
if (source[ns].sflags & SDISTANT) |
123 |
source[ns].sflags |= SSKIP; |
124 |
} else if (m->otype == MAT_SPOT) { |
125 |
source[ns].sflags |= SSPOT; |
126 |
if ((source[ns].sl.s = makespot(m)) == NULL) |
127 |
goto memerr; |
128 |
if (source[ns].sflags & SFLAT && |
129 |
!checkspot(source[ns].sl.s,source[ns].snorm)) { |
130 |
objerror(o, WARNING, |
131 |
"invalid spotlight direction"); |
132 |
source[ns].sflags |= SSKIP; |
133 |
} |
134 |
} |
135 |
#if SHADCACHE |
136 |
initobscache(ns); |
137 |
#endif |
138 |
if (!(source[ns].sflags & SSKIP)) |
139 |
foundsource++; |
140 |
} |
141 |
if (!foundsource) { |
142 |
error(WARNING, "no light sources found"); |
143 |
return; |
144 |
} |
145 |
markvirtuals(); /* find and add virtual sources */ |
146 |
/* allocate our contribution arrays */ |
147 |
maxcntr = nsources + MAXSPART; /* start with this many */ |
148 |
srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB)); |
149 |
cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR)); |
150 |
if ((srccnt == NULL) | (cntord == NULL)) |
151 |
goto memerr; |
152 |
return; |
153 |
memerr: |
154 |
error(SYSTEM, "out of memory in marksources"); |
155 |
} |
156 |
|
157 |
|
158 |
extern void |
159 |
freesources(void) /* free all source structures */ |
160 |
{ |
161 |
if (nsources > 0) { |
162 |
#if SHADCACHE |
163 |
while (nsources--) |
164 |
freeobscache(&source[nsources]); |
165 |
#endif |
166 |
free((void *)source); |
167 |
source = NULL; |
168 |
nsources = 0; |
169 |
} |
170 |
if (maxcntr <= 0) |
171 |
return; |
172 |
free((void *)srccnt); |
173 |
srccnt = NULL; |
174 |
free((void *)cntord); |
175 |
cntord = NULL; |
176 |
maxcntr = 0; |
177 |
} |
178 |
|
179 |
|
180 |
extern int |
181 |
srcray( /* send a ray to a source, return domega */ |
182 |
register RAY *sr, /* returned source ray */ |
183 |
RAY *r, /* ray which hit object */ |
184 |
SRCINDEX *si /* source sample index */ |
185 |
) |
186 |
{ |
187 |
double d; /* distance to source */ |
188 |
register SRCREC *srcp; |
189 |
|
190 |
rayorigin(sr, SHADOW, r, NULL); /* ignore limits */ |
191 |
|
192 |
if (r == NULL) |
193 |
sr->rmax = 0.0; |
194 |
|
195 |
while ((d = nextssamp(sr, si)) != 0.0) { |
196 |
sr->rsrc = si->sn; /* remember source */ |
197 |
srcp = source + si->sn; |
198 |
if (srcp->sflags & SDISTANT) { |
199 |
if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s)) |
200 |
continue; |
201 |
return(1); /* sample OK */ |
202 |
} |
203 |
/* local source */ |
204 |
/* check proximity */ |
205 |
if (srcp->sflags & SPROX && d > srcp->sl.prox) |
206 |
continue; |
207 |
/* check angle */ |
208 |
if (srcp->sflags & SSPOT) { |
209 |
if (spotout(sr, srcp->sl.s)) |
210 |
continue; |
211 |
/* adjust solid angle */ |
212 |
si->dom *= d*d; |
213 |
d += srcp->sl.s->flen; |
214 |
si->dom /= d*d; |
215 |
} |
216 |
return(1); /* sample OK */ |
217 |
} |
218 |
return(0); /* no more samples */ |
219 |
} |
220 |
|
221 |
|
222 |
extern void |
223 |
srcvalue( /* punch ray to source and compute value */ |
224 |
register RAY *r |
225 |
) |
226 |
{ |
227 |
register SRCREC *sp; |
228 |
|
229 |
sp = &source[r->rsrc]; |
230 |
if (sp->sflags & SVIRTUAL) { /* virtual source */ |
231 |
/* check intersection */ |
232 |
if (!(*ofun[sp->so->otype].funp)(sp->so, r)) |
233 |
return; |
234 |
if (!rayshade(r, r->ro->omod)) /* compute contribution */ |
235 |
goto nomat; |
236 |
rayparticipate(r); |
237 |
return; |
238 |
} |
239 |
/* compute intersection */ |
240 |
if (sp->sflags & SDISTANT ? sourcehit(r) : |
241 |
(*ofun[sp->so->otype].funp)(sp->so, r)) { |
242 |
if (sp->sa.success >= 0) |
243 |
sp->sa.success++; |
244 |
if (!rayshade(r, r->ro->omod)) /* compute contribution */ |
245 |
goto nomat; |
246 |
rayparticipate(r); |
247 |
return; |
248 |
} |
249 |
/* we missed our mark! */ |
250 |
if (sp->sa.success < 0) |
251 |
return; /* bitched already */ |
252 |
sp->sa.success -= AIMREQT; |
253 |
if (sp->sa.success >= 0) |
254 |
return; /* leniency */ |
255 |
sprintf(errmsg, "aiming failure for light source \"%s\"", |
256 |
sp->so->oname); |
257 |
error(WARNING, errmsg); /* issue warning */ |
258 |
return; |
259 |
nomat: |
260 |
objerror(r->ro, USER, "material not found"); |
261 |
} |
262 |
|
263 |
|
264 |
static int |
265 |
transillum( /* check if material is transparent illum */ |
266 |
OBJECT obj |
267 |
) |
268 |
{ |
269 |
OBJREC *m = findmaterial(objptr(obj)); |
270 |
|
271 |
if (m == NULL) |
272 |
return(1); |
273 |
if (m->otype != MAT_ILLUM) |
274 |
return(0); |
275 |
return(!m->oargs.nsargs || !strcmp(m->oargs.sarg[0], VOIDID)); |
276 |
} |
277 |
|
278 |
|
279 |
extern int |
280 |
sourcehit( /* check to see if ray hit distant source */ |
281 |
register RAY *r |
282 |
) |
283 |
{ |
284 |
int glowsrc = -1; |
285 |
int transrc = -1; |
286 |
int first, last; |
287 |
register int i; |
288 |
|
289 |
if (r->rsrc >= 0) { /* check only one if aimed */ |
290 |
first = last = r->rsrc; |
291 |
} else { /* otherwise check all */ |
292 |
first = 0; last = nsources-1; |
293 |
} |
294 |
for (i = first; i <= last; i++) { |
295 |
if ((source[i].sflags & (SDISTANT|SVIRTUAL)) != SDISTANT) |
296 |
continue; |
297 |
/* |
298 |
* Check to see if ray is within |
299 |
* solid angle of source. |
300 |
*/ |
301 |
if (2.*PI*(1. - DOT(source[i].sloc,r->rdir)) > source[i].ss2) |
302 |
continue; |
303 |
/* is it the only possibility? */ |
304 |
if (first == last) { |
305 |
r->ro = source[i].so; |
306 |
break; |
307 |
} |
308 |
/* |
309 |
* If it's a glow or transparent illum, just remember it. |
310 |
*/ |
311 |
if (source[i].sflags & SSKIP) { |
312 |
if (glowsrc < 0) |
313 |
glowsrc = i; |
314 |
continue; |
315 |
} |
316 |
if (transillum(source[i].so->omod)) { |
317 |
if (transrc < 0) |
318 |
transrc = i; |
319 |
continue; |
320 |
} |
321 |
r->ro = source[i].so; /* otherwise, use first hit */ |
322 |
break; |
323 |
} |
324 |
/* |
325 |
* Do we need fallback? |
326 |
*/ |
327 |
if (r->ro == NULL) { |
328 |
if (transrc >= 0 && r->crtype & (AMBIENT|SPECULAR)) |
329 |
return(0); /* avoid overcounting */ |
330 |
if (glowsrc >= 0) |
331 |
r->ro = source[glowsrc].so; |
332 |
else |
333 |
return(0); /* nothing usable */ |
334 |
} |
335 |
/* |
336 |
* Make assignments. |
337 |
*/ |
338 |
r->robj = objndx(r->ro); |
339 |
for (i = 0; i < 3; i++) |
340 |
r->ron[i] = -r->rdir[i]; |
341 |
r->rod = 1.0; |
342 |
r->pert[0] = r->pert[1] = r->pert[2] = 0.0; |
343 |
r->uv[0] = r->uv[1] = 0.0; |
344 |
r->rox = NULL; |
345 |
return(1); |
346 |
} |
347 |
|
348 |
|
349 |
static int |
350 |
cntcmp( /* contribution compare (descending) */ |
351 |
const void *p1, |
352 |
const void *p2 |
353 |
) |
354 |
{ |
355 |
register const CNTPTR *sc1 = (const CNTPTR *)p1; |
356 |
register const CNTPTR *sc2 = (const CNTPTR *)p2; |
357 |
|
358 |
if (sc1->brt > sc2->brt) |
359 |
return(-1); |
360 |
if (sc1->brt < sc2->brt) |
361 |
return(1); |
362 |
return(0); |
363 |
} |
364 |
|
365 |
|
366 |
extern void |
367 |
direct( /* add direct component */ |
368 |
RAY *r, /* ray that hit surface */ |
369 |
srcdirf_t *f, /* direct component coefficient function */ |
370 |
void *p /* data for f */ |
371 |
) |
372 |
{ |
373 |
register int sn; |
374 |
register CONTRIB *scp; |
375 |
SRCINDEX si; |
376 |
int nshadcheck, ncnts; |
377 |
int nhits; |
378 |
double prob, ourthresh, hwt; |
379 |
RAY sr; |
380 |
/* NOTE: srccnt and cntord global so no recursion */ |
381 |
if (nsources <= 0) |
382 |
return; /* no sources?! */ |
383 |
/* potential contributions */ |
384 |
initsrcindex(&si); |
385 |
for (sn = 0; srcray(&sr, r, &si); sn++) { |
386 |
if (sn >= maxcntr) { |
387 |
maxcntr = sn + MAXSPART; |
388 |
srccnt = (CONTRIB *)realloc((void *)srccnt, |
389 |
maxcntr*sizeof(CONTRIB)); |
390 |
cntord = (CNTPTR *)realloc((void *)cntord, |
391 |
maxcntr*sizeof(CNTPTR)); |
392 |
if ((srccnt == NULL) | (cntord == NULL)) |
393 |
error(SYSTEM, "out of memory in direct"); |
394 |
} |
395 |
cntord[sn].sndx = sn; |
396 |
scp = srccnt + sn; |
397 |
scp->sno = sr.rsrc; |
398 |
/* compute coefficient */ |
399 |
(*f)(scp->coef, p, sr.rdir, si.dom); |
400 |
cntord[sn].brt = intens(scp->coef); |
401 |
if (cntord[sn].brt <= 0.0) |
402 |
continue; |
403 |
#if SHADCACHE |
404 |
/* check shadow cache */ |
405 |
if (si.np == 1 && srcblocked(&sr)) { |
406 |
cntord[sn].brt = 0.0; |
407 |
continue; |
408 |
} |
409 |
#endif |
410 |
VCOPY(scp->dir, sr.rdir); |
411 |
copycolor(sr.rcoef, scp->coef); |
412 |
/* compute potential */ |
413 |
sr.revf = srcvalue; |
414 |
rayvalue(&sr); |
415 |
multcolor(sr.rcol, sr.rcoef); |
416 |
copycolor(scp->val, sr.rcol); |
417 |
cntord[sn].brt = bright(sr.rcol); |
418 |
} |
419 |
/* sort contributions */ |
420 |
qsort(cntord, sn, sizeof(CNTPTR), cntcmp); |
421 |
{ /* find last */ |
422 |
register int l, m; |
423 |
|
424 |
ncnts = l = sn; |
425 |
sn = 0; |
426 |
while ((m = (sn + ncnts) >> 1) != l) { |
427 |
if (cntord[m].brt > 0.0) |
428 |
sn = m; |
429 |
else |
430 |
ncnts = m; |
431 |
l = m; |
432 |
} |
433 |
} |
434 |
if (ncnts == 0) |
435 |
return; /* no contributions! */ |
436 |
/* accumulate tail */ |
437 |
for (sn = ncnts-1; sn > 0; sn--) |
438 |
cntord[sn-1].brt += cntord[sn].brt; |
439 |
/* compute number to check */ |
440 |
nshadcheck = pow((double)ncnts, shadcert) + .5; |
441 |
/* modify threshold */ |
442 |
ourthresh = shadthresh / r->rweight; |
443 |
/* test for shadows */ |
444 |
for (nhits = 0, hwt = 0.0, sn = 0; sn < ncnts; |
445 |
hwt += (double)source[scp->sno].nhits / |
446 |
(double)source[scp->sno].ntests, |
447 |
sn++) { |
448 |
/* check threshold */ |
449 |
if ((sn+nshadcheck>=ncnts ? cntord[sn].brt : |
450 |
cntord[sn].brt-cntord[sn+nshadcheck].brt) |
451 |
< ourthresh*bright(r->rcol)) |
452 |
break; |
453 |
scp = srccnt + cntord[sn].sndx; |
454 |
/* test for hit */ |
455 |
rayorigin(&sr, SHADOW, r, NULL); |
456 |
copycolor(sr.rcoef, scp->coef); |
457 |
VCOPY(sr.rdir, scp->dir); |
458 |
sr.rsrc = scp->sno; |
459 |
/* keep statistics */ |
460 |
if (source[scp->sno].ntests++ > 0xfffffff0) { |
461 |
source[scp->sno].ntests >>= 1; |
462 |
source[scp->sno].nhits >>= 1; |
463 |
} |
464 |
if (localhit(&sr, &thescene) && |
465 |
( sr.ro != source[scp->sno].so || |
466 |
source[scp->sno].sflags & SFOLLOW )) { |
467 |
/* follow entire path */ |
468 |
raycont(&sr); |
469 |
if (trace != NULL) |
470 |
(*trace)(&sr); /* trace execution */ |
471 |
if (bright(sr.rcol) <= FTINY) { |
472 |
#if SHADCACHE |
473 |
if ((scp <= srccnt || scp[-1].sno != scp->sno) |
474 |
&& (scp >= srccnt+ncnts-1 || |
475 |
scp[1].sno != scp->sno)) |
476 |
srcblocker(&sr); |
477 |
#endif |
478 |
continue; /* missed! */ |
479 |
} |
480 |
rayparticipate(&sr); |
481 |
multcolor(sr.rcol, sr.rcoef); |
482 |
copycolor(scp->val, sr.rcol); |
483 |
} else if (trace != NULL && |
484 |
(source[scp->sno].sflags & (SDISTANT|SVIRTUAL|SFOLLOW)) |
485 |
== (SDISTANT|SFOLLOW) && |
486 |
sourcehit(&sr) && rayshade(&sr, sr.ro->omod)) { |
487 |
(*trace)(&sr); /* trace execution */ |
488 |
/* skip call to rayparticipate() & scp->val update */ |
489 |
} |
490 |
/* add contribution if hit */ |
491 |
addcolor(r->rcol, scp->val); |
492 |
nhits++; |
493 |
source[scp->sno].nhits++; |
494 |
} |
495 |
/* source hit rate */ |
496 |
if (hwt > FTINY) |
497 |
hwt = (double)nhits / hwt; |
498 |
else |
499 |
hwt = 0.5; |
500 |
#ifdef DEBUG |
501 |
sprintf(errmsg, "%d tested, %d untested, %f conditional hit rate\n", |
502 |
sn, ncnts-sn, hwt); |
503 |
eputs(errmsg); |
504 |
#endif |
505 |
/* add in untested sources */ |
506 |
for ( ; sn < ncnts; sn++) { |
507 |
scp = srccnt + cntord[sn].sndx; |
508 |
prob = hwt * (double)source[scp->sno].nhits / |
509 |
(double)source[scp->sno].ntests; |
510 |
if (prob < 1.0) |
511 |
scalecolor(scp->val, prob); |
512 |
addcolor(r->rcol, scp->val); |
513 |
} |
514 |
} |
515 |
|
516 |
|
517 |
extern void |
518 |
srcscatter( /* compute source scattering into ray */ |
519 |
register RAY *r |
520 |
) |
521 |
{ |
522 |
int oldsampndx; |
523 |
int nsamps; |
524 |
RAY sr; |
525 |
SRCINDEX si; |
526 |
double t, d; |
527 |
double re, ge, be; |
528 |
COLOR cvext; |
529 |
int i, j; |
530 |
|
531 |
if (r->slights == NULL || r->slights[0] == 0 |
532 |
|| r->gecc >= 1.-FTINY || r->rot >= FHUGE) |
533 |
return; |
534 |
if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1) |
535 |
nsamps = 1; |
536 |
#if MAXSSAMP |
537 |
else if (nsamps > MAXSSAMP) |
538 |
nsamps = MAXSSAMP; |
539 |
#endif |
540 |
oldsampndx = samplendx; |
541 |
samplendx = random()&0x7fff; /* randomize */ |
542 |
for (i = r->slights[0]; i > 0; i--) { /* for each source */ |
543 |
for (j = 0; j < nsamps; j++) { /* for each sample position */ |
544 |
samplendx++; |
545 |
t = r->rot * (j+frandom())/nsamps; |
546 |
/* extinction */ |
547 |
re = t*colval(r->cext,RED); |
548 |
ge = t*colval(r->cext,GRN); |
549 |
be = t*colval(r->cext,BLU); |
550 |
setcolor(cvext, re > 92. ? 0. : exp(-re), |
551 |
ge > 92. ? 0. : exp(-ge), |
552 |
be > 92. ? 0. : exp(-be)); |
553 |
if (intens(cvext) <= FTINY) |
554 |
break; /* too far away */ |
555 |
sr.rorg[0] = r->rorg[0] + r->rdir[0]*t; |
556 |
sr.rorg[1] = r->rorg[1] + r->rdir[1]*t; |
557 |
sr.rorg[2] = r->rorg[2] + r->rdir[2]*t; |
558 |
initsrcindex(&si); /* sample ray to this source */ |
559 |
si.sn = r->slights[i]; |
560 |
nopart(&si, &sr); |
561 |
if (!srcray(&sr, NULL, &si) || |
562 |
sr.rsrc != r->slights[i]) |
563 |
continue; /* no path */ |
564 |
#if SHADCACHE |
565 |
if (srcblocked(&sr)) /* check shadow cache */ |
566 |
continue; |
567 |
#endif |
568 |
copycolor(sr.cext, r->cext); |
569 |
copycolor(sr.albedo, r->albedo); |
570 |
sr.gecc = r->gecc; |
571 |
sr.slights = r->slights; |
572 |
rayvalue(&sr); /* eval. source ray */ |
573 |
if (bright(sr.rcol) <= FTINY) { |
574 |
#if SHADCACHE |
575 |
srcblocker(&sr); /* add blocker to cache */ |
576 |
#endif |
577 |
continue; |
578 |
} |
579 |
if (r->gecc <= FTINY) /* compute P(theta) */ |
580 |
d = 1.; |
581 |
else { |
582 |
d = DOT(r->rdir, sr.rdir); |
583 |
d = 1. + r->gecc*r->gecc - 2.*r->gecc*d; |
584 |
d = (1. - r->gecc*r->gecc) / (d*sqrt(d)); |
585 |
} |
586 |
/* other factors */ |
587 |
d *= si.dom * r->rot / (4.*PI*nsamps); |
588 |
multcolor(sr.rcol, r->cext); |
589 |
multcolor(sr.rcol, r->albedo); |
590 |
scalecolor(sr.rcol, d); |
591 |
multcolor(sr.rcol, cvext); |
592 |
addcolor(r->rcol, sr.rcol); /* add it in */ |
593 |
} |
594 |
} |
595 |
samplendx = oldsampndx; |
596 |
} |
597 |
|
598 |
|
599 |
/**************************************************************** |
600 |
* The following macros were separated from the m_light() routine |
601 |
* because they are very nasty and difficult to understand. |
602 |
*/ |
603 |
|
604 |
/* illumblock * |
605 |
* |
606 |
* We cannot allow an illum to pass to another illum, because that |
607 |
* would almost certainly constitute overcounting. |
608 |
* However, we do allow an illum to pass to another illum |
609 |
* that is actually going to relay to a virtual light source. |
610 |
* We also prevent an illum from passing to a glow; this provides a |
611 |
* convenient mechanism for defining detailed light source |
612 |
* geometry behind (or inside) an effective radiator. |
613 |
*/ |
614 |
|
615 |
static int |
616 |
weaksrcmat(OBJECT obj) /* identify material */ |
617 |
{ |
618 |
OBJREC *m = findmaterial(objptr(obj)); |
619 |
|
620 |
if (m == NULL) return(0); |
621 |
return((m->otype==MAT_ILLUM) | (m->otype==MAT_GLOW)); |
622 |
} |
623 |
|
624 |
#define illumblock(m, r) (!(source[r->rsrc].sflags&SVIRTUAL) && \ |
625 |
r->rod > 0.0 && \ |
626 |
weaksrcmat(source[r->rsrc].so->omod)) |
627 |
|
628 |
/* wrongsource * |
629 |
* |
630 |
* This source is the wrong source (ie. overcounted) if we are |
631 |
* aimed to a different source than the one we hit and the one |
632 |
* we hit is not an illum that should be passed. |
633 |
*/ |
634 |
|
635 |
#define wrongsource(m, r) (r->rsrc>=0 && source[r->rsrc].so!=r->ro && \ |
636 |
(m->otype!=MAT_ILLUM || illumblock(m,r))) |
637 |
|
638 |
/* distglow * |
639 |
* |
640 |
* A distant glow is an object that sometimes acts as a light source, |
641 |
* but is too far away from the test point to be one in this case. |
642 |
* (Glows with negative radii should NEVER participate in illumination.) |
643 |
*/ |
644 |
|
645 |
#define distglow(m, r, d) (m->otype==MAT_GLOW && \ |
646 |
m->oargs.farg[3] >= -FTINY && \ |
647 |
d > m->oargs.farg[3]) |
648 |
|
649 |
/* badcomponent * |
650 |
* |
651 |
* We must avoid counting light sources in the ambient calculation, |
652 |
* since the direct component is handled separately. Therefore, any |
653 |
* ambient ray which hits an active light source must be discarded. |
654 |
* The same is true for stray specular samples, since the specular |
655 |
* contribution from light sources is calculated separately. |
656 |
*/ |
657 |
|
658 |
#define badcomponent(m, r) (r->crtype&(AMBIENT|SPECULAR) && \ |
659 |
!(r->crtype&SHADOW || r->rod < 0.0 || \ |
660 |
/* not 100% correct */ distglow(m, r, r->rot))) |
661 |
|
662 |
/* passillum * |
663 |
* |
664 |
* An illum passes to another material type when we didn't hit it |
665 |
* on purpose (as part of a direct calculation), or it is relaying |
666 |
* a virtual light source. |
667 |
*/ |
668 |
|
669 |
#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
670 |
(r->rsrc<0 || source[r->rsrc].so!=r->ro || \ |
671 |
source[r->rsrc].sflags&SVIRTUAL)) |
672 |
|
673 |
/* srcignore * |
674 |
* |
675 |
* The -dv flag is normally on for sources to be visible. |
676 |
*/ |
677 |
|
678 |
#define srcignore(m, r) !(directvis || r->crtype&SHADOW || \ |
679 |
distglow(m, r, raydist(r,PRIMARY))) |
680 |
|
681 |
|
682 |
extern int |
683 |
m_light( /* ray hit a light source */ |
684 |
register OBJREC *m, |
685 |
register RAY *r |
686 |
) |
687 |
{ |
688 |
/* check for over-counting */ |
689 |
if (badcomponent(m, r)) { |
690 |
setcolor(r->rcoef, 0.0, 0.0, 0.0); |
691 |
return(1); |
692 |
} |
693 |
if (wrongsource(m, r)) { |
694 |
setcolor(r->rcoef, 0.0, 0.0, 0.0); |
695 |
return(1); |
696 |
} |
697 |
/* check for passed illum */ |
698 |
if (passillum(m, r)) { |
699 |
if (m->oargs.nsargs && strcmp(m->oargs.sarg[0], VOIDID)) |
700 |
return(rayshade(r,lastmod(objndx(m),m->oargs.sarg[0]))); |
701 |
raytrans(r); |
702 |
return(1); |
703 |
} |
704 |
/* check for invisibility */ |
705 |
if (srcignore(m, r)) { |
706 |
setcolor(r->rcoef, 0.0, 0.0, 0.0); |
707 |
return(1); |
708 |
} |
709 |
/* otherwise treat as source */ |
710 |
/* check for behind */ |
711 |
if (r->rod < 0.0) |
712 |
return(1); |
713 |
/* check for outside spot */ |
714 |
if (m->otype==MAT_SPOT && spotout(r, makespot(m))) |
715 |
return(1); |
716 |
/* get distribution pattern */ |
717 |
raytexture(r, m->omod); |
718 |
/* get source color */ |
719 |
setcolor(r->rcol, m->oargs.farg[0], |
720 |
m->oargs.farg[1], |
721 |
m->oargs.farg[2]); |
722 |
/* modify value */ |
723 |
multcolor(r->rcol, r->pcol); |
724 |
return(1); |
725 |
} |