1 |
/* Copyright (c) 1995 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 "otypes.h" |
18 |
|
19 |
#include "source.h" |
20 |
|
21 |
#include "random.h" |
22 |
|
23 |
extern double ssampdist; /* scatter sampling distance */ |
24 |
|
25 |
#ifndef MAXSSAMP |
26 |
#define MAXSSAMP 16 /* maximum samples per ray */ |
27 |
#endif |
28 |
|
29 |
/* |
30 |
* Structures used by direct() |
31 |
*/ |
32 |
|
33 |
typedef struct { |
34 |
int sno; /* source number */ |
35 |
FVECT dir; /* source direction */ |
36 |
COLOR coef; /* material coefficient */ |
37 |
COLOR val; /* contribution */ |
38 |
} CONTRIB; /* direct contribution */ |
39 |
|
40 |
typedef struct { |
41 |
int sndx; /* source index (to CONTRIB array) */ |
42 |
float brt; /* brightness (for comparison) */ |
43 |
} CNTPTR; /* contribution pointer */ |
44 |
|
45 |
static CONTRIB *srccnt; /* source contributions in direct() */ |
46 |
static CNTPTR *cntord; /* source ordering in direct() */ |
47 |
static int maxcntr = 0; /* size of contribution arrays */ |
48 |
|
49 |
|
50 |
marksources() /* find and mark source objects */ |
51 |
{ |
52 |
int foundsource = 0; |
53 |
int i; |
54 |
register OBJREC *o, *m; |
55 |
register int ns; |
56 |
/* initialize dispatch table */ |
57 |
initstypes(); |
58 |
/* find direct sources */ |
59 |
for (i = 0; i < nobjects; i++) { |
60 |
|
61 |
o = objptr(i); |
62 |
|
63 |
if (!issurface(o->otype) || o->omod == OVOID) |
64 |
continue; |
65 |
|
66 |
m = objptr(o->omod); |
67 |
|
68 |
if (!islight(m->otype)) |
69 |
continue; |
70 |
|
71 |
if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 : |
72 |
m->otype == MAT_SPOT ? 7 : 3)) |
73 |
objerror(m, USER, "bad # arguments"); |
74 |
|
75 |
if (m->otype == MAT_GLOW && |
76 |
o->otype != OBJ_SOURCE && |
77 |
m->oargs.farg[3] <= FTINY) |
78 |
continue; /* don't bother */ |
79 |
if (m->oargs.farg[0] <= FTINY && m->oargs.farg[1] <= FTINY && |
80 |
m->oargs.farg[2] <= FTINY) |
81 |
continue; /* don't bother */ |
82 |
|
83 |
if (sfun[o->otype].of == NULL || |
84 |
sfun[o->otype].of->setsrc == NULL) |
85 |
objerror(o, USER, "illegal material"); |
86 |
|
87 |
if ((ns = newsource()) < 0) |
88 |
goto memerr; |
89 |
|
90 |
setsource(&source[ns], o); |
91 |
|
92 |
if (m->otype == MAT_GLOW) { |
93 |
source[ns].sflags |= SPROX; |
94 |
source[ns].sl.prox = m->oargs.farg[3]; |
95 |
if (source[ns].sflags & SDISTANT) |
96 |
source[ns].sflags |= SSKIP; |
97 |
} else if (m->otype == MAT_SPOT) { |
98 |
source[ns].sflags |= SSPOT; |
99 |
if ((source[ns].sl.s = makespot(m)) == NULL) |
100 |
goto memerr; |
101 |
if (source[ns].sflags & SFLAT && |
102 |
!checkspot(source[ns].sl.s,source[ns].snorm)) { |
103 |
objerror(o, WARNING, |
104 |
"invalid spotlight direction"); |
105 |
source[ns].sflags |= SSKIP; |
106 |
} |
107 |
} |
108 |
if (!(source[ns].sflags & SSKIP)) |
109 |
foundsource++; |
110 |
} |
111 |
if (!foundsource) { |
112 |
error(WARNING, "no light sources found"); |
113 |
return; |
114 |
} |
115 |
markvirtuals(); /* find and add virtual sources */ |
116 |
/* allocate our contribution arrays */ |
117 |
maxcntr = nsources + MAXSPART; /* start with this many */ |
118 |
srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB)); |
119 |
cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR)); |
120 |
if (srccnt == NULL | cntord == NULL) |
121 |
goto memerr; |
122 |
return; |
123 |
memerr: |
124 |
error(SYSTEM, "out of memory in marksources"); |
125 |
} |
126 |
|
127 |
|
128 |
srcray(sr, r, si) /* send a ray to a source, return domega */ |
129 |
register RAY *sr; /* returned source ray */ |
130 |
RAY *r; /* ray which hit object */ |
131 |
SRCINDEX *si; /* source sample index */ |
132 |
{ |
133 |
double d; /* distance to source */ |
134 |
register SRCREC *srcp; |
135 |
|
136 |
rayorigin(sr, r, SHADOW, 1.0); /* ignore limits */ |
137 |
|
138 |
while ((d = nextssamp(sr, si)) != 0.0) { |
139 |
sr->rsrc = si->sn; /* remember source */ |
140 |
srcp = source + si->sn; |
141 |
if (srcp->sflags & SDISTANT) { |
142 |
if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s)) |
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continue; |
144 |
return(1); /* sample OK */ |
145 |
} |
146 |
/* local source */ |
147 |
/* check proximity */ |
148 |
if (srcp->sflags & SPROX && d > srcp->sl.prox) |
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continue; |
150 |
/* check angle */ |
151 |
if (srcp->sflags & SSPOT) { |
152 |
if (spotout(sr, srcp->sl.s)) |
153 |
continue; |
154 |
/* adjust solid angle */ |
155 |
si->dom *= d*d; |
156 |
d += srcp->sl.s->flen; |
157 |
si->dom /= d*d; |
158 |
} |
159 |
return(1); /* sample OK */ |
160 |
} |
161 |
return(0); /* no more samples */ |
162 |
} |
163 |
|
164 |
|
165 |
srcvalue(r) /* punch ray to source and compute value */ |
166 |
register RAY *r; |
167 |
{ |
168 |
register SRCREC *sp; |
169 |
|
170 |
sp = &source[r->rsrc]; |
171 |
if (sp->sflags & SVIRTUAL) { /* virtual source */ |
172 |
/* check intersection */ |
173 |
if (!(*ofun[sp->so->otype].funp)(sp->so, r)) |
174 |
return; |
175 |
if (!rayshade(r, r->ro->omod)) /* compute contribution */ |
176 |
goto nomat; |
177 |
rayparticipate(r); |
178 |
return; |
179 |
} |
180 |
/* compute intersection */ |
181 |
if (sp->sflags & SDISTANT ? sourcehit(r) : |
182 |
(*ofun[sp->so->otype].funp)(sp->so, r)) { |
183 |
if (sp->sa.success >= 0) |
184 |
sp->sa.success++; |
185 |
if (!rayshade(r, r->ro->omod)) /* compute contribution */ |
186 |
goto nomat; |
187 |
rayparticipate(r); |
188 |
return; |
189 |
} |
190 |
/* we missed our mark! */ |
191 |
if (sp->sa.success < 0) |
192 |
return; /* bitched already */ |
193 |
sp->sa.success -= AIMREQT; |
194 |
if (sp->sa.success >= 0) |
195 |
return; /* leniency */ |
196 |
sprintf(errmsg, "aiming failure for light source \"%s\"", |
197 |
sp->so->oname); |
198 |
error(WARNING, errmsg); /* issue warning */ |
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return; |
200 |
nomat: |
201 |
objerror(r->ro, USER, "material not found"); |
202 |
} |
203 |
|
204 |
|
205 |
sourcehit(r) /* check to see if ray hit distant source */ |
206 |
register RAY *r; |
207 |
{ |
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int first, last; |
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register int i; |
210 |
|
211 |
if (r->rsrc >= 0) { /* check only one if aimed */ |
212 |
first = last = r->rsrc; |
213 |
} else { /* otherwise check all */ |
214 |
first = 0; last = nsources-1; |
215 |
} |
216 |
for (i = first; i <= last; i++) |
217 |
if ((source[i].sflags & (SDISTANT|SVIRTUAL)) == SDISTANT) |
218 |
/* |
219 |
* Check to see if ray is within |
220 |
* solid angle of source. |
221 |
*/ |
222 |
if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir)) |
223 |
<= source[i].ss2) { |
224 |
r->ro = source[i].so; |
225 |
if (!(source[i].sflags & SSKIP)) |
226 |
break; |
227 |
} |
228 |
|
229 |
if (r->ro != NULL) { |
230 |
for (i = 0; i < 3; i++) |
231 |
r->ron[i] = -r->rdir[i]; |
232 |
r->rod = 1.0; |
233 |
r->rox = NULL; |
234 |
return(1); |
235 |
} |
236 |
return(0); |
237 |
} |
238 |
|
239 |
|
240 |
static int |
241 |
cntcmp(sc1, sc2) /* contribution compare (descending) */ |
242 |
register CNTPTR *sc1, *sc2; |
243 |
{ |
244 |
if (sc1->brt > sc2->brt) |
245 |
return(-1); |
246 |
if (sc1->brt < sc2->brt) |
247 |
return(1); |
248 |
return(0); |
249 |
} |
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|
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|
252 |
direct(r, f, p) /* add direct component */ |
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RAY *r; /* ray that hit surface */ |
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int (*f)(); /* direct component coefficient function */ |
255 |
char *p; /* data for f */ |
256 |
{ |
257 |
extern int (*trace)(); |
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register int sn; |
259 |
register CONTRIB *scp; |
260 |
SRCINDEX si; |
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int nshadcheck, ncnts; |
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int nhits; |
263 |
double prob, ourthresh, hwt; |
264 |
RAY sr; |
265 |
/* NOTE: srccnt and cntord global so no recursion */ |
266 |
if (nsources <= 0) |
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return; /* no sources?! */ |
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/* potential contributions */ |
269 |
initsrcindex(&si); |
270 |
for (sn = 0; srcray(&sr, r, &si); sn++) { |
271 |
if (sn >= maxcntr) { |
272 |
maxcntr = sn + MAXSPART; |
273 |
srccnt = (CONTRIB *)realloc((char *)srccnt, |
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maxcntr*sizeof(CONTRIB)); |
275 |
cntord = (CNTPTR *)realloc((char *)cntord, |
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maxcntr*sizeof(CNTPTR)); |
277 |
if (srccnt == NULL | cntord == NULL) |
278 |
error(SYSTEM, "out of memory in direct"); |
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} |
280 |
cntord[sn].sndx = sn; |
281 |
scp = srccnt + sn; |
282 |
scp->sno = sr.rsrc; |
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/* compute coefficient */ |
284 |
(*f)(scp->coef, p, sr.rdir, si.dom); |
285 |
cntord[sn].brt = bright(scp->coef); |
286 |
if (cntord[sn].brt <= 0.0) |
287 |
continue; |
288 |
VCOPY(scp->dir, sr.rdir); |
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/* compute potential */ |
290 |
sr.revf = srcvalue; |
291 |
rayvalue(&sr); |
292 |
copycolor(scp->val, sr.rcol); |
293 |
multcolor(scp->val, scp->coef); |
294 |
cntord[sn].brt = bright(scp->val); |
295 |
} |
296 |
/* sort contributions */ |
297 |
qsort(cntord, sn, sizeof(CNTPTR), cntcmp); |
298 |
{ /* find last */ |
299 |
register int l, m; |
300 |
|
301 |
ncnts = l = sn; |
302 |
sn = 0; |
303 |
while ((m = (sn + ncnts) >> 1) != l) { |
304 |
if (cntord[m].brt > 0.0) |
305 |
sn = m; |
306 |
else |
307 |
ncnts = m; |
308 |
l = m; |
309 |
} |
310 |
} |
311 |
if (ncnts == 0) |
312 |
return; /* no contributions! */ |
313 |
/* accumulate tail */ |
314 |
for (sn = ncnts-1; sn > 0; sn--) |
315 |
cntord[sn-1].brt += cntord[sn].brt; |
316 |
/* compute number to check */ |
317 |
nshadcheck = pow((double)ncnts, shadcert) + .5; |
318 |
/* modify threshold */ |
319 |
ourthresh = shadthresh / r->rweight; |
320 |
/* test for shadows */ |
321 |
for (nhits = 0, hwt = 0.0, sn = 0; sn < ncnts; |
322 |
hwt += (double)source[scp->sno].nhits / |
323 |
(double)source[scp->sno].ntests, |
324 |
sn++) { |
325 |
/* check threshold */ |
326 |
if ((sn+nshadcheck>=ncnts ? cntord[sn].brt : |
327 |
cntord[sn].brt-cntord[sn+nshadcheck].brt) |
328 |
< ourthresh*bright(r->rcol)) |
329 |
break; |
330 |
scp = srccnt + cntord[sn].sndx; |
331 |
/* test for hit */ |
332 |
rayorigin(&sr, r, SHADOW, 1.0); |
333 |
VCOPY(sr.rdir, scp->dir); |
334 |
sr.rsrc = scp->sno; |
335 |
source[scp->sno].ntests++; /* keep statistics */ |
336 |
if (localhit(&sr, &thescene) && |
337 |
( sr.ro != source[scp->sno].so || |
338 |
source[scp->sno].sflags & SFOLLOW )) { |
339 |
/* follow entire path */ |
340 |
raycont(&sr); |
341 |
rayparticipate(&sr); |
342 |
if (trace != NULL) |
343 |
(*trace)(&sr); /* trace execution */ |
344 |
if (bright(sr.rcol) <= FTINY) |
345 |
continue; /* missed! */ |
346 |
copycolor(scp->val, sr.rcol); |
347 |
multcolor(scp->val, scp->coef); |
348 |
} |
349 |
/* add contribution if hit */ |
350 |
addcolor(r->rcol, scp->val); |
351 |
nhits++; |
352 |
source[scp->sno].nhits++; |
353 |
} |
354 |
/* source hit rate */ |
355 |
if (hwt > FTINY) |
356 |
hwt = (double)nhits / hwt; |
357 |
else |
358 |
hwt = 0.5; |
359 |
#ifdef DEBUG |
360 |
sprintf(errmsg, "%d tested, %d untested, %f conditional hit rate\n", |
361 |
sn, ncnts-sn, hwt); |
362 |
eputs(errmsg); |
363 |
#endif |
364 |
/* add in untested sources */ |
365 |
for ( ; sn < ncnts; sn++) { |
366 |
scp = srccnt + cntord[sn].sndx; |
367 |
prob = hwt * (double)source[scp->sno].nhits / |
368 |
(double)source[scp->sno].ntests; |
369 |
if (prob > 1.0) |
370 |
prob = 1.0; |
371 |
scalecolor(scp->val, prob); |
372 |
addcolor(r->rcol, scp->val); |
373 |
} |
374 |
} |
375 |
|
376 |
|
377 |
srcscatter(r) /* compute source scattering into ray */ |
378 |
register RAY *r; |
379 |
{ |
380 |
int oldsampndx; |
381 |
int nsamps; |
382 |
RAY sr; |
383 |
SRCINDEX si; |
384 |
double t, lastt, d; |
385 |
COLOR cumval, ctmp; |
386 |
int i, j; |
387 |
|
388 |
if (r->slights == NULL || r->slights[0] == 0 |
389 |
|| r->gecc >= 1.-FTINY || r->rot >= FHUGE) |
390 |
return; |
391 |
if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1) |
392 |
nsamps = 1; |
393 |
#if MAXSSAMP |
394 |
else if (nsamps > MAXSSAMP) |
395 |
nsamps = MAXSSAMP; |
396 |
#endif |
397 |
oldsampndx = samplendx; |
398 |
samplendx = random()&0x7fff; /* randomize */ |
399 |
for (i = r->slights[0]; i > 0; i--) { /* for each source */ |
400 |
setcolor(cumval, 0., 0., 0.); |
401 |
lastt = r->rot; |
402 |
for (j = nsamps; j-- > 0; ) { /* for each sample position */ |
403 |
samplendx++; |
404 |
t = r->rot * (j+frandom())/nsamps; |
405 |
sr.rorg[0] = r->rorg[0] + r->rdir[0]*t; |
406 |
sr.rorg[1] = r->rorg[1] + r->rdir[1]*t; |
407 |
sr.rorg[2] = r->rorg[2] + r->rdir[2]*t; |
408 |
sr.rmax = 0.; |
409 |
initsrcindex(&si); /* sample ray to this source */ |
410 |
si.sn = r->slights[i]; |
411 |
nopart(&si, &sr); |
412 |
if (!srcray(&sr, NULL, &si) || |
413 |
sr.rsrc != r->slights[i]) |
414 |
continue; /* no path */ |
415 |
copycolor(sr.cext, r->cext); |
416 |
sr.albedo = r->albedo; |
417 |
sr.gecc = r->gecc; |
418 |
rayvalue(&sr); /* eval. source ray */ |
419 |
if (bright(sr.rcol) <= FTINY) |
420 |
continue; |
421 |
/* compute fall-off */ |
422 |
d = lastt - t; |
423 |
setcolor(ctmp, 1.-d*colval(r->cext,RED), |
424 |
1.-d*colval(r->cext,GRN), |
425 |
1.-d*colval(r->cext,BLU)); |
426 |
multcolor(cumval, ctmp); |
427 |
lastt = t; |
428 |
if (r->gecc <= FTINY) /* compute P(theta) */ |
429 |
d = 1.; |
430 |
else { |
431 |
d = DOT(r->rdir, sr.rdir); |
432 |
d = sqrt(1. + r->gecc*r->gecc - 2.*r->gecc*d); |
433 |
d = (1. - r->gecc*r->gecc) / (d*d*d); |
434 |
} |
435 |
/* other factors */ |
436 |
d *= si.dom * r->albedo * r->rot / (4.*PI*nsamps); |
437 |
multcolor(sr.rcol, r->cext); |
438 |
scalecolor(sr.rcol, d); |
439 |
addcolor(cumval, sr.rcol); |
440 |
} |
441 |
/* final fall-off */ |
442 |
setcolor(ctmp, 1.-lastt*colval(r->cext,RED), |
443 |
1.-lastt*colval(r->cext,GRN), |
444 |
1.-lastt*colval(r->cext,BLU)); |
445 |
multcolor(cumval, ctmp); |
446 |
addcolor(r->rcol, cumval); /* sum into ray result */ |
447 |
} |
448 |
samplendx = oldsampndx; |
449 |
} |
450 |
|
451 |
|
452 |
/**************************************************************** |
453 |
* The following macros were separated from the m_light() routine |
454 |
* because they are very nasty and difficult to understand. |
455 |
*/ |
456 |
|
457 |
/* illumblock * |
458 |
* |
459 |
* We cannot allow an illum to pass to another illum, because that |
460 |
* would almost certainly constitute overcounting. |
461 |
* However, we do allow an illum to pass to another illum |
462 |
* that is actually going to relay to a virtual light source. |
463 |
* We also prevent an illum from passing to a glow; this provides a |
464 |
* convenient mechanism for defining detailed light source |
465 |
* geometry behind (or inside) an effective radiator. |
466 |
*/ |
467 |
|
468 |
static int weaksrcmod(obj) int obj; /* efficiency booster function */ |
469 |
{register OBJREC *o = objptr(obj); |
470 |
return(o->otype==MAT_ILLUM|o->otype==MAT_GLOW);} |
471 |
|
472 |
#define illumblock(m, r) (!(source[r->rsrc].sflags&SVIRTUAL) && \ |
473 |
r->rod > 0.0 && \ |
474 |
weaksrcmod(source[r->rsrc].so->omod)) |
475 |
|
476 |
/* wrongsource * |
477 |
* |
478 |
* This source is the wrong source (ie. overcounted) if we are |
479 |
* aimed to a different source than the one we hit and the one |
480 |
* we hit is not an illum that should be passed. |
481 |
*/ |
482 |
|
483 |
#define wrongsource(m, r) (r->rsrc>=0 && source[r->rsrc].so!=r->ro && \ |
484 |
(m->otype!=MAT_ILLUM || illumblock(m,r))) |
485 |
|
486 |
/* distglow * |
487 |
* |
488 |
* A distant glow is an object that sometimes acts as a light source, |
489 |
* but is too far away from the test point to be one in this case. |
490 |
* (Glows with negative radii should NEVER participate in illumination.) |
491 |
*/ |
492 |
|
493 |
#define distglow(m, r, d) (m->otype==MAT_GLOW && \ |
494 |
m->oargs.farg[3] >= -FTINY && \ |
495 |
d > m->oargs.farg[3]) |
496 |
|
497 |
/* badcomponent * |
498 |
* |
499 |
* We must avoid counting light sources in the ambient calculation, |
500 |
* since the direct component is handled separately. Therefore, any |
501 |
* ambient ray which hits an active light source must be discarded. |
502 |
* The same is true for stray specular samples, since the specular |
503 |
* contribution from light sources is calculated separately. |
504 |
*/ |
505 |
|
506 |
#define badcomponent(m, r) (r->crtype&(AMBIENT|SPECULAR) && \ |
507 |
!(r->crtype&SHADOW || r->rod < 0.0 || \ |
508 |
/* not 100% correct */ distglow(m, r, r->rot))) |
509 |
|
510 |
/* passillum * |
511 |
* |
512 |
* An illum passes to another material type when we didn't hit it |
513 |
* on purpose (as part of a direct calculation), or it is relaying |
514 |
* a virtual light source. |
515 |
*/ |
516 |
|
517 |
#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
518 |
(r->rsrc<0 || source[r->rsrc].so!=r->ro || \ |
519 |
source[r->rsrc].sflags&SVIRTUAL)) |
520 |
|
521 |
/* srcignore * |
522 |
* |
523 |
* The -dv flag is normally on for sources to be visible. |
524 |
*/ |
525 |
|
526 |
#define srcignore(m, r) !(directvis || r->crtype&SHADOW || \ |
527 |
distglow(m, r, raydist(r,PRIMARY))) |
528 |
|
529 |
|
530 |
m_light(m, r) /* ray hit a light source */ |
531 |
register OBJREC *m; |
532 |
register RAY *r; |
533 |
{ |
534 |
/* check for over-counting */ |
535 |
if (badcomponent(m, r)) |
536 |
return(1); |
537 |
if (wrongsource(m, r)) |
538 |
return(1); |
539 |
/* check for passed illum */ |
540 |
if (passillum(m, r)) { |
541 |
if (m->oargs.nsargs && strcmp(m->oargs.sarg[0], VOIDID)) |
542 |
return(rayshade(r, modifier(m->oargs.sarg[0]))); |
543 |
raytrans(r); |
544 |
return(1); |
545 |
} |
546 |
/* otherwise treat as source */ |
547 |
/* check for behind */ |
548 |
if (r->rod < 0.0) |
549 |
return(1); |
550 |
/* check for invisibility */ |
551 |
if (srcignore(m, r)) |
552 |
return(1); |
553 |
/* check for outside spot */ |
554 |
if (m->otype==MAT_SPOT && spotout(r, makespot(m))) |
555 |
return(1); |
556 |
/* get distribution pattern */ |
557 |
raytexture(r, m->omod); |
558 |
/* get source color */ |
559 |
setcolor(r->rcol, m->oargs.farg[0], |
560 |
m->oargs.farg[1], |
561 |
m->oargs.farg[2]); |
562 |
/* modify value */ |
563 |
multcolor(r->rcol, r->pcol); |
564 |
return(1); |
565 |
} |