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 |
|
*/ |
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, 1)) |
142 |
> |
if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s)) |
143 |
|
continue; |
144 |
|
return(1); /* sample OK */ |
145 |
|
} |
149 |
|
continue; |
150 |
|
/* check angle */ |
151 |
|
if (srcp->sflags & SSPOT) { |
152 |
< |
if (spotout(sr, srcp->sl.s, 0)) |
152 |
> |
if (spotout(sr, srcp->sl.s)) |
153 |
|
continue; |
154 |
|
/* adjust solid angle */ |
155 |
|
si->dom *= d*d; |
174 |
|
return; |
175 |
|
if (!rayshade(r, r->ro->omod)) /* compute contribution */ |
176 |
|
goto nomat; |
177 |
+ |
rayparticipate(r); |
178 |
|
return; |
179 |
|
} |
180 |
|
/* compute intersection */ |
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! */ |
339 |
|
/* follow entire path */ |
340 |
|
if (!raycont(&sr)) |
341 |
|
objerror(sr.ro, USER, "material not found"); |
342 |
+ |
rayparticipate(&sr); |
343 |
|
if (trace != NULL) |
344 |
|
(*trace)(&sr); /* trace execution */ |
345 |
|
if (bright(sr.rcol) <= FTINY) |
375 |
|
} |
376 |
|
|
377 |
|
|
378 |
+ |
srcscatter(r) /* compute source scattering into ray */ |
379 |
+ |
register RAY *r; |
380 |
+ |
{ |
381 |
+ |
int oldsampndx; |
382 |
+ |
int nsamps; |
383 |
+ |
RAY sr; |
384 |
+ |
SRCINDEX si; |
385 |
+ |
double t, lastt, d; |
386 |
+ |
COLOR cumval, ctmp; |
387 |
+ |
int i, j; |
388 |
+ |
|
389 |
+ |
if (r->slights == NULL || r->slights[0] == 0 |
390 |
+ |
|| r->gecc >= 1.-FTINY || r->rot >= FHUGE) |
391 |
+ |
return; |
392 |
+ |
if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1) |
393 |
+ |
nsamps = 1; |
394 |
+ |
#if MAXSSAMP |
395 |
+ |
else if (nsamps > MAXSSAMP) |
396 |
+ |
nsamps = MAXSSAMP; |
397 |
+ |
#endif |
398 |
+ |
oldsampndx = samplendx; |
399 |
+ |
samplendx = random()&0x7fff; /* randomize */ |
400 |
+ |
for (i = r->slights[0]; i > 0; i--) { /* for each source */ |
401 |
+ |
setcolor(cumval, 0., 0., 0.); |
402 |
+ |
lastt = r->rot; |
403 |
+ |
for (j = nsamps; j-- > 0; ) { /* for each sample position */ |
404 |
+ |
samplendx++; |
405 |
+ |
t = r->rot * (j+frandom())/nsamps; |
406 |
+ |
sr.rorg[0] = r->rorg[0] + r->rdir[0]*t; |
407 |
+ |
sr.rorg[1] = r->rorg[1] + r->rdir[1]*t; |
408 |
+ |
sr.rorg[2] = r->rorg[2] + r->rdir[2]*t; |
409 |
+ |
sr.rmax = 0.; |
410 |
+ |
initsrcindex(&si); /* sample ray to this source */ |
411 |
+ |
si.sn = r->slights[i]; |
412 |
+ |
nopart(&si, &sr); |
413 |
+ |
if (!srcray(&sr, NULL, &si) || |
414 |
+ |
sr.rsrc != r->slights[i]) |
415 |
+ |
continue; /* no path */ |
416 |
+ |
copycolor(sr.cext, r->cext); |
417 |
+ |
sr.albedo = r->albedo; |
418 |
+ |
sr.gecc = r->gecc; |
419 |
+ |
rayvalue(&sr); /* eval. source ray */ |
420 |
+ |
if (bright(sr.rcol) <= FTINY) |
421 |
+ |
continue; |
422 |
+ |
/* compute fall-off */ |
423 |
+ |
d = lastt - t; |
424 |
+ |
setcolor(ctmp, 1.-d*colval(r->cext,RED), |
425 |
+ |
1.-d*colval(r->cext,GRN), |
426 |
+ |
1.-d*colval(r->cext,BLU)); |
427 |
+ |
multcolor(cumval, ctmp); |
428 |
+ |
lastt = t; |
429 |
+ |
if (r->gecc <= FTINY) /* compute P(theta) */ |
430 |
+ |
d = 1.; |
431 |
+ |
else { |
432 |
+ |
d = DOT(r->rdir, sr.rdir); |
433 |
+ |
d = sqrt(1. + r->gecc*r->gecc - 2.*r->gecc*d); |
434 |
+ |
d = (1. - r->gecc*r->gecc) / (d*d*d); |
435 |
+ |
} |
436 |
+ |
/* other factors */ |
437 |
+ |
d *= si.dom * r->albedo * r->rot / (4.*PI*nsamps); |
438 |
+ |
multcolor(sr.rcol, r->cext); |
439 |
+ |
scalecolor(sr.rcol, d); |
440 |
+ |
addcolor(cumval, sr.rcol); |
441 |
+ |
} |
442 |
+ |
/* final fall-off */ |
443 |
+ |
setcolor(ctmp, 1.-lastt*colval(r->cext,RED), |
444 |
+ |
1.-lastt*colval(r->cext,GRN), |
445 |
+ |
1.-lastt*colval(r->cext,BLU)); |
446 |
+ |
multcolor(cumval, ctmp); |
447 |
+ |
addcolor(r->rcol, cumval); /* sum into ray result */ |
448 |
+ |
} |
449 |
+ |
samplendx = oldsampndx; |
450 |
+ |
} |
451 |
+ |
|
452 |
+ |
|
453 |
|
/**************************************************************** |
454 |
|
* The following macros were separated from the m_light() routine |
455 |
|
* because they are very nasty and difficult to understand. |
552 |
|
if (srcignore(m, r)) |
553 |
|
return(1); |
554 |
|
/* check for outside spot */ |
555 |
< |
if (m->otype==MAT_SPOT && spotout(r, makespot(m), r->rot>=FHUGE)) |
555 |
> |
if (m->otype==MAT_SPOT && spotout(r, makespot(m))) |
556 |
|
return(1); |
557 |
|
/* get distribution pattern */ |
558 |
|
raytexture(r, m->omod); |