1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: raytrace.c,v 2.77 2019/02/22 19:42:27 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* raytrace.c - routines for tracing and shading rays. |
6 |
* |
7 |
* External symbols declared in ray.h |
8 |
*/ |
9 |
|
10 |
#include "copyright.h" |
11 |
|
12 |
#include "ray.h" |
13 |
#include "source.h" |
14 |
#include "otypes.h" |
15 |
#include "otspecial.h" |
16 |
#include "random.h" |
17 |
#include "pmap.h" |
18 |
|
19 |
#define MAXCSET ((MAXSET+1)*2-1) /* maximum check set size */ |
20 |
|
21 |
RNUMBER raynum = 0; /* next unique ray number */ |
22 |
RNUMBER nrays = 0; /* number of calls to localhit */ |
23 |
|
24 |
static RREAL Lambfa[5] = {PI, PI, PI, 0.0, 0.0}; |
25 |
OBJREC Lamb = { |
26 |
OVOID, MAT_PLASTIC, "Lambertian", |
27 |
{NULL, Lambfa, 0, 5}, NULL |
28 |
}; /* a Lambertian surface */ |
29 |
|
30 |
OBJREC Aftplane; /* aft clipping plane object */ |
31 |
|
32 |
#define RAYHIT (-1) /* return value for intercepted ray */ |
33 |
|
34 |
static int raymove(FVECT pos, OBJECT *cxs, int dirf, RAY *r, CUBE *cu); |
35 |
static int checkhit(RAY *r, CUBE *cu, OBJECT *cxs); |
36 |
static void checkset(OBJECT *os, OBJECT *cs); |
37 |
|
38 |
|
39 |
int |
40 |
rayorigin( /* start new ray from old one */ |
41 |
RAY *r, |
42 |
int rt, |
43 |
const RAY *ro, |
44 |
const COLOR rc |
45 |
) |
46 |
{ |
47 |
double rw, re; |
48 |
/* assign coefficient/weight */ |
49 |
if (rc == NULL) { |
50 |
rw = 1.0; |
51 |
setcolor(r->rcoef, 1., 1., 1.); |
52 |
} else { |
53 |
rw = intens(rc); |
54 |
if (rw > 1.0) |
55 |
rw = 1.0; /* avoid calculation growth */ |
56 |
if (rc != r->rcoef) |
57 |
copycolor(r->rcoef, rc); |
58 |
} |
59 |
if ((r->parent = ro) == NULL) { /* primary ray */ |
60 |
r->rlvl = 0; |
61 |
r->rweight = rw; |
62 |
r->crtype = r->rtype = rt; |
63 |
r->rsrc = -1; |
64 |
r->clipset = NULL; |
65 |
r->revf = raytrace; |
66 |
copycolor(r->cext, cextinction); |
67 |
copycolor(r->albedo, salbedo); |
68 |
r->gecc = seccg; |
69 |
r->slights = NULL; |
70 |
} else { /* spawned ray */ |
71 |
if (ro->rot >= FHUGE) { |
72 |
memset(r, 0, sizeof(RAY)); |
73 |
return(-1); /* illegal continuation */ |
74 |
} |
75 |
r->rlvl = ro->rlvl; |
76 |
if (rt & RAYREFL) { |
77 |
r->rlvl++; |
78 |
r->rsrc = -1; |
79 |
r->clipset = ro->clipset; |
80 |
r->rmax = 0.0; |
81 |
} else { |
82 |
r->rsrc = ro->rsrc; |
83 |
r->clipset = ro->newcset; |
84 |
r->rmax = ro->rmax <= FTINY ? 0.0 : ro->rmax - ro->rot; |
85 |
} |
86 |
r->revf = ro->revf; |
87 |
copycolor(r->cext, ro->cext); |
88 |
copycolor(r->albedo, ro->albedo); |
89 |
r->gecc = ro->gecc; |
90 |
r->slights = ro->slights; |
91 |
r->crtype = ro->crtype | (r->rtype = rt); |
92 |
VCOPY(r->rorg, ro->rop); |
93 |
r->rweight = ro->rweight * rw; |
94 |
/* estimate extinction */ |
95 |
re = colval(ro->cext,RED) < colval(ro->cext,GRN) ? |
96 |
colval(ro->cext,RED) : colval(ro->cext,GRN); |
97 |
if (colval(ro->cext,BLU) < re) re = colval(ro->cext,BLU); |
98 |
re *= ro->rot; |
99 |
if (re > 0.1) { |
100 |
if (re > 92.) { |
101 |
r->rweight = 0.0; |
102 |
} else { |
103 |
r->rweight *= exp(-re); |
104 |
} |
105 |
} |
106 |
} |
107 |
rayclear(r); |
108 |
if (r->rweight <= 0.0) /* check for expiration */ |
109 |
return(-1); |
110 |
if (r->crtype & SHADOW) /* shadow commitment */ |
111 |
return(0); |
112 |
/* ambient in photon map? */ |
113 |
if (ro != NULL && ro->crtype & AMBIENT) { |
114 |
if (causticPhotonMapping) |
115 |
return(-1); |
116 |
if (photonMapping && rt != TRANS) |
117 |
return(-1); |
118 |
} |
119 |
if ((maxdepth <= 0) & (rc != NULL)) { /* Russian roulette */ |
120 |
if (minweight <= 0.0) |
121 |
error(USER, "zero ray weight in Russian roulette"); |
122 |
if ((maxdepth < 0) & (r->rlvl > -maxdepth)) |
123 |
return(-1); /* upper reflection limit */ |
124 |
if (r->rweight >= minweight) |
125 |
return(0); |
126 |
if (frandom() > r->rweight/minweight) |
127 |
return(-1); |
128 |
rw = minweight/r->rweight; /* promote survivor */ |
129 |
scalecolor(r->rcoef, rw); |
130 |
r->rweight = minweight; |
131 |
return(0); |
132 |
} |
133 |
return((r->rweight >= minweight) & (r->rlvl <= abs(maxdepth)) ? 0 : -1); |
134 |
} |
135 |
|
136 |
|
137 |
void |
138 |
rayclear( /* clear a ray for (re)evaluation */ |
139 |
RAY *r |
140 |
) |
141 |
{ |
142 |
r->rno = raynum++; |
143 |
r->newcset = r->clipset; |
144 |
r->hitf = rayhit; |
145 |
r->robj = OVOID; |
146 |
r->ro = NULL; |
147 |
r->rox = NULL; |
148 |
r->rxt = r->rmt = r->rot = FHUGE; |
149 |
r->pert[0] = r->pert[1] = r->pert[2] = 0.0; |
150 |
r->uv[0] = r->uv[1] = 0.0; |
151 |
setcolor(r->pcol, 1.0, 1.0, 1.0); |
152 |
setcolor(r->mcol, 0.0, 0.0, 0.0); |
153 |
setcolor(r->rcol, 0.0, 0.0, 0.0); |
154 |
} |
155 |
|
156 |
|
157 |
void |
158 |
raytrace( /* trace a ray and compute its value */ |
159 |
RAY *r |
160 |
) |
161 |
{ |
162 |
if (localhit(r, &thescene)) |
163 |
raycont(r); /* hit local surface, evaluate */ |
164 |
else if (r->ro == &Aftplane) { |
165 |
r->ro = NULL; /* hit aft clipping plane */ |
166 |
r->rot = FHUGE; |
167 |
} else if (sourcehit(r)) |
168 |
rayshade(r, r->ro->omod); /* distant source */ |
169 |
|
170 |
if (trace != NULL) |
171 |
(*trace)(r); /* trace execution */ |
172 |
|
173 |
rayparticipate(r); /* for participating medium */ |
174 |
} |
175 |
|
176 |
|
177 |
void |
178 |
raycont( /* check for clipped object and continue */ |
179 |
RAY *r |
180 |
) |
181 |
{ |
182 |
if ((r->clipset != NULL && inset(r->clipset, r->ro->omod)) || |
183 |
!rayshade(r, r->ro->omod)) |
184 |
raytrans(r); |
185 |
} |
186 |
|
187 |
|
188 |
void |
189 |
raytrans( /* transmit ray as is */ |
190 |
RAY *r |
191 |
) |
192 |
{ |
193 |
RAY tr; |
194 |
|
195 |
rayorigin(&tr, TRANS, r, NULL); /* always continue */ |
196 |
VCOPY(tr.rdir, r->rdir); |
197 |
rayvalue(&tr); |
198 |
copycolor(r->mcol, tr.mcol); |
199 |
copycolor(r->rcol, tr.rcol); |
200 |
r->rmt = r->rot + tr.rmt; |
201 |
r->rxt = r->rot + tr.rxt; |
202 |
} |
203 |
|
204 |
|
205 |
int |
206 |
raytirrad( /* irradiance hack */ |
207 |
OBJREC *m, |
208 |
RAY *r |
209 |
) |
210 |
{ |
211 |
if (ofun[m->otype].flags & (T_M|T_X) && m->otype != MAT_CLIP) { |
212 |
if (istransp(m->otype) || isBSDFproxy(m)) { |
213 |
raytrans(r); |
214 |
return(1); |
215 |
} |
216 |
if (!islight(m->otype)) |
217 |
return((*ofun[Lamb.otype].funp)(&Lamb, r)); |
218 |
} |
219 |
return(0); /* not a qualifying surface */ |
220 |
} |
221 |
|
222 |
|
223 |
int |
224 |
rayshade( /* shade ray r with material mod */ |
225 |
RAY *r, |
226 |
int mod |
227 |
) |
228 |
{ |
229 |
int tst_irrad = do_irrad && !(r->crtype & ~(PRIMARY|TRANS)); |
230 |
OBJREC *m; |
231 |
|
232 |
r->rxt = r->rot; /* preset effective ray length */ |
233 |
for ( ; mod != OVOID; mod = m->omod) { |
234 |
m = objptr(mod); |
235 |
/****** unnecessary test since modifier() is always called |
236 |
if (!ismodifier(m->otype)) { |
237 |
sprintf(errmsg, "illegal modifier \"%s\"", m->oname); |
238 |
error(USER, errmsg); |
239 |
} |
240 |
******/ |
241 |
/* hack for irradiance calculation */ |
242 |
if (tst_irrad && raytirrad(m, r)) |
243 |
return(1); |
244 |
|
245 |
if ((*ofun[m->otype].funp)(m, r)) |
246 |
return(1); /* materials call raytexture() */ |
247 |
} |
248 |
return(0); /* no material! */ |
249 |
} |
250 |
|
251 |
|
252 |
void |
253 |
rayparticipate( /* compute ray medium participation */ |
254 |
RAY *r |
255 |
) |
256 |
{ |
257 |
COLOR ce, ca; |
258 |
double re, ge, be; |
259 |
|
260 |
if (intens(r->cext) <= 1./FHUGE) |
261 |
return; /* no medium */ |
262 |
re = r->rot*colval(r->cext,RED); |
263 |
ge = r->rot*colval(r->cext,GRN); |
264 |
be = r->rot*colval(r->cext,BLU); |
265 |
if (r->crtype & SHADOW) { /* no scattering for sources */ |
266 |
re *= 1. - colval(r->albedo,RED); |
267 |
ge *= 1. - colval(r->albedo,GRN); |
268 |
be *= 1. - colval(r->albedo,BLU); |
269 |
} |
270 |
setcolor(ce, re<=FTINY ? 1. : re>92. ? 0. : exp(-re), |
271 |
ge<=FTINY ? 1. : ge>92. ? 0. : exp(-ge), |
272 |
be<=FTINY ? 1. : be>92. ? 0. : exp(-be)); |
273 |
multcolor(r->rcol, ce); /* path extinction */ |
274 |
if (r->crtype & SHADOW || intens(r->albedo) <= FTINY) |
275 |
return; /* no scattering */ |
276 |
|
277 |
/* PMAP: indirect inscattering accounted for by volume photons? */ |
278 |
if (!volumePhotonMapping) { |
279 |
setcolor(ca, |
280 |
colval(r->albedo,RED)*colval(ambval,RED)*(1.-colval(ce,RED)), |
281 |
colval(r->albedo,GRN)*colval(ambval,GRN)*(1.-colval(ce,GRN)), |
282 |
colval(r->albedo,BLU)*colval(ambval,BLU)*(1.-colval(ce,BLU))); |
283 |
addcolor(r->rcol, ca); /* ambient in scattering */ |
284 |
} |
285 |
|
286 |
srcscatter(r); /* source in scattering */ |
287 |
} |
288 |
|
289 |
|
290 |
void |
291 |
raytexture( /* get material modifiers */ |
292 |
RAY *r, |
293 |
OBJECT mod |
294 |
) |
295 |
{ |
296 |
OBJREC *m; |
297 |
/* execute textures and patterns */ |
298 |
for ( ; mod != OVOID; mod = m->omod) { |
299 |
m = objptr(mod); |
300 |
/****** unnecessary test since modifier() is always called |
301 |
if (!ismodifier(m->otype)) { |
302 |
sprintf(errmsg, "illegal modifier \"%s\"", m->oname); |
303 |
error(USER, errmsg); |
304 |
} |
305 |
******/ |
306 |
if ((*ofun[m->otype].funp)(m, r)) { |
307 |
sprintf(errmsg, "conflicting material \"%s\"", |
308 |
m->oname); |
309 |
objerror(r->ro, USER, errmsg); |
310 |
} |
311 |
} |
312 |
} |
313 |
|
314 |
|
315 |
int |
316 |
raymixture( /* mix modifiers */ |
317 |
RAY *r, |
318 |
OBJECT fore, |
319 |
OBJECT back, |
320 |
double coef |
321 |
) |
322 |
{ |
323 |
RAY fr, br; |
324 |
double mfore, mback; |
325 |
int foremat, backmat; |
326 |
int i; |
327 |
/* bound coefficient */ |
328 |
if (coef > 1.0) |
329 |
coef = 1.0; |
330 |
else if (coef < 0.0) |
331 |
coef = 0.0; |
332 |
/* compute foreground and background */ |
333 |
foremat = backmat = 0; |
334 |
/* foreground */ |
335 |
fr = *r; |
336 |
if (coef > FTINY) { |
337 |
fr.rweight *= coef; |
338 |
scalecolor(fr.rcoef, coef); |
339 |
foremat = rayshade(&fr, fore); |
340 |
} |
341 |
/* background */ |
342 |
br = *r; |
343 |
if (coef < 1.0-FTINY) { |
344 |
br.rweight *= 1.0-coef; |
345 |
scalecolor(br.rcoef, 1.0-coef); |
346 |
backmat = rayshade(&br, back); |
347 |
} |
348 |
/* check for transparency */ |
349 |
if (backmat ^ foremat) { |
350 |
if (backmat && coef > FTINY) |
351 |
raytrans(&fr); |
352 |
else if (foremat && coef < 1.0-FTINY) |
353 |
raytrans(&br); |
354 |
} |
355 |
/* mix perturbations */ |
356 |
for (i = 0; i < 3; i++) |
357 |
r->pert[i] = coef*fr.pert[i] + (1.0-coef)*br.pert[i]; |
358 |
/* mix pattern colors */ |
359 |
scalecolor(fr.pcol, coef); |
360 |
scalecolor(br.pcol, 1.0-coef); |
361 |
copycolor(r->pcol, fr.pcol); |
362 |
addcolor(r->pcol, br.pcol); |
363 |
/* return value tells if material */ |
364 |
if (!foremat & !backmat) |
365 |
return(0); |
366 |
/* mix returned ray values */ |
367 |
scalecolor(fr.rcol, coef); |
368 |
scalecolor(br.rcol, 1.0-coef); |
369 |
copycolor(r->rcol, fr.rcol); |
370 |
addcolor(r->rcol, br.rcol); |
371 |
scalecolor(fr.mcol, coef); |
372 |
scalecolor(br.mcol, 1.0-coef); |
373 |
copycolor(r->mcol, fr.mcol); |
374 |
addcolor(r->mcol, br.mcol); |
375 |
mfore = bright(fr.mcol); mback = bright(br.mcol); |
376 |
r->rmt = mfore > mback ? fr.rmt : br.rmt; |
377 |
r->rxt = bright(fr.rcol)-mfore > bright(br.rcol)-mback ? |
378 |
fr.rxt : br.rxt; |
379 |
return(1); |
380 |
} |
381 |
|
382 |
|
383 |
double |
384 |
raydist( /* compute (cumulative) ray distance */ |
385 |
const RAY *r, |
386 |
int flags |
387 |
) |
388 |
{ |
389 |
double sum = 0.0; |
390 |
|
391 |
while (r != NULL && r->crtype&flags) { |
392 |
sum += r->rot; |
393 |
r = r->parent; |
394 |
} |
395 |
return(sum); |
396 |
} |
397 |
|
398 |
|
399 |
void |
400 |
raycontrib( /* compute (cumulative) ray contribution */ |
401 |
RREAL rc[3], |
402 |
const RAY *r, |
403 |
int flags |
404 |
) |
405 |
{ |
406 |
static int warnedPM = 0; |
407 |
|
408 |
rc[0] = rc[1] = rc[2] = 1.; |
409 |
|
410 |
while (r != NULL && r->crtype&flags) { |
411 |
int i = 3; |
412 |
while (i--) |
413 |
rc[i] *= colval(r->rcoef,i); |
414 |
/* check for participating medium */ |
415 |
if (!warnedPM && (bright(r->cext) > FTINY) | |
416 |
(bright(r->albedo) > FTINY)) { |
417 |
error(WARNING, |
418 |
"ray contribution calculation does not support participating media"); |
419 |
warnedPM++; |
420 |
} |
421 |
r = r->parent; |
422 |
} |
423 |
} |
424 |
|
425 |
|
426 |
double |
427 |
raynormal( /* compute perturbed normal for ray */ |
428 |
FVECT norm, |
429 |
RAY *r |
430 |
) |
431 |
{ |
432 |
double newdot; |
433 |
int i; |
434 |
|
435 |
/* The perturbation is added to the surface normal to obtain |
436 |
* the new normal. If the new normal would affect the surface |
437 |
* orientation wrt. the ray, a correction is made. The method is |
438 |
* still fraught with problems since reflected rays and similar |
439 |
* directions calculated from the surface normal may spawn rays behind |
440 |
* the surface. The only solution is to curb textures at high |
441 |
* incidence (namely, keep DOT(rdir,pert) < Rdot). |
442 |
*/ |
443 |
|
444 |
for (i = 0; i < 3; i++) |
445 |
norm[i] = r->ron[i] + r->pert[i]; |
446 |
|
447 |
if (normalize(norm) == 0.0) { |
448 |
objerror(r->ro, WARNING, "illegal normal perturbation"); |
449 |
VCOPY(norm, r->ron); |
450 |
return(r->rod); |
451 |
} |
452 |
newdot = -DOT(norm, r->rdir); |
453 |
if ((newdot > 0.0) != (r->rod > 0.0)) { /* fix orientation */ |
454 |
for (i = 0; i < 3; i++) |
455 |
norm[i] += 2.0*newdot*r->rdir[i]; |
456 |
newdot = -newdot; |
457 |
} |
458 |
return(newdot); |
459 |
} |
460 |
|
461 |
|
462 |
void |
463 |
newrayxf( /* get new tranformation matrix for ray */ |
464 |
RAY *r |
465 |
) |
466 |
{ |
467 |
static struct xfn { |
468 |
struct xfn *next; |
469 |
FULLXF xf; |
470 |
} xfseed = { &xfseed }, *xflast = &xfseed; |
471 |
struct xfn *xp; |
472 |
const RAY *rp; |
473 |
|
474 |
/* |
475 |
* Search for transform in circular list that |
476 |
* has no associated ray in the tree. |
477 |
*/ |
478 |
xp = xflast; |
479 |
for (rp = r->parent; rp != NULL; rp = rp->parent) |
480 |
if (rp->rox == &xp->xf) { /* xp in use */ |
481 |
xp = xp->next; /* move to next */ |
482 |
if (xp == xflast) { /* need new one */ |
483 |
xp = (struct xfn *)bmalloc(sizeof(struct xfn)); |
484 |
if (xp == NULL) |
485 |
error(SYSTEM, |
486 |
"out of memory in newrayxf"); |
487 |
/* insert in list */ |
488 |
xp->next = xflast->next; |
489 |
xflast->next = xp; |
490 |
break; /* we're done */ |
491 |
} |
492 |
rp = r; /* start check over */ |
493 |
} |
494 |
/* got it */ |
495 |
r->rox = &xp->xf; |
496 |
xflast = xp; |
497 |
} |
498 |
|
499 |
|
500 |
void |
501 |
flipsurface( /* reverse surface orientation */ |
502 |
RAY *r |
503 |
) |
504 |
{ |
505 |
r->rod = -r->rod; |
506 |
r->ron[0] = -r->ron[0]; |
507 |
r->ron[1] = -r->ron[1]; |
508 |
r->ron[2] = -r->ron[2]; |
509 |
r->pert[0] = -r->pert[0]; |
510 |
r->pert[1] = -r->pert[1]; |
511 |
r->pert[2] = -r->pert[2]; |
512 |
} |
513 |
|
514 |
|
515 |
void |
516 |
rayhit( /* standard ray hit test */ |
517 |
OBJECT *oset, |
518 |
RAY *r |
519 |
) |
520 |
{ |
521 |
OBJREC *o; |
522 |
int i; |
523 |
|
524 |
for (i = oset[0]; i > 0; i--) { |
525 |
o = objptr(oset[i]); |
526 |
if ((*ofun[o->otype].funp)(o, r)) |
527 |
r->robj = oset[i]; |
528 |
} |
529 |
} |
530 |
|
531 |
|
532 |
int |
533 |
localhit( /* check for hit in the octree */ |
534 |
RAY *r, |
535 |
CUBE *scene |
536 |
) |
537 |
{ |
538 |
OBJECT cxset[MAXCSET+1]; /* set of checked objects */ |
539 |
FVECT curpos; /* current cube position */ |
540 |
int sflags; /* sign flags */ |
541 |
double t, dt; |
542 |
int i; |
543 |
|
544 |
nrays++; /* increment trace counter */ |
545 |
sflags = 0; |
546 |
for (i = 0; i < 3; i++) { |
547 |
curpos[i] = r->rorg[i]; |
548 |
if (r->rdir[i] > 1e-7) |
549 |
sflags |= 1 << i; |
550 |
else if (r->rdir[i] < -1e-7) |
551 |
sflags |= 0x10 << i; |
552 |
} |
553 |
if (!sflags) { |
554 |
error(WARNING, "zero ray direction in localhit"); |
555 |
return(0); |
556 |
} |
557 |
/* start off assuming nothing hit */ |
558 |
if (r->rmax > FTINY) { /* except aft plane if one */ |
559 |
r->ro = &Aftplane; |
560 |
r->rot = r->rmax; |
561 |
VSUM(r->rop, r->rorg, r->rdir, r->rot); |
562 |
} |
563 |
/* find global cube entrance point */ |
564 |
t = 0.0; |
565 |
if (!incube(scene, curpos)) { |
566 |
/* find distance to entry */ |
567 |
for (i = 0; i < 3; i++) { |
568 |
/* plane in our direction */ |
569 |
if (sflags & 1<<i) |
570 |
dt = scene->cuorg[i]; |
571 |
else if (sflags & 0x10<<i) |
572 |
dt = scene->cuorg[i] + scene->cusize; |
573 |
else |
574 |
continue; |
575 |
/* distance to the plane */ |
576 |
dt = (dt - r->rorg[i])/r->rdir[i]; |
577 |
if (dt > t) |
578 |
t = dt; /* farthest face is the one */ |
579 |
} |
580 |
t += FTINY; /* fudge to get inside cube */ |
581 |
if (t >= r->rot) /* clipped already */ |
582 |
return(0); |
583 |
/* advance position */ |
584 |
VSUM(curpos, curpos, r->rdir, t); |
585 |
|
586 |
if (!incube(scene, curpos)) /* non-intersecting ray */ |
587 |
return(0); |
588 |
} |
589 |
cxset[0] = 0; |
590 |
raymove(curpos, cxset, sflags, r, scene); |
591 |
return((r->ro != NULL) & (r->ro != &Aftplane)); |
592 |
} |
593 |
|
594 |
|
595 |
static int |
596 |
raymove( /* check for hit as we move */ |
597 |
FVECT pos, /* current position, modified herein */ |
598 |
OBJECT *cxs, /* checked objects, modified by checkhit */ |
599 |
int dirf, /* direction indicators to speed tests */ |
600 |
RAY *r, |
601 |
CUBE *cu |
602 |
) |
603 |
{ |
604 |
int ax; |
605 |
double dt, t; |
606 |
|
607 |
if (istree(cu->cutree)) { /* recurse on subcubes */ |
608 |
CUBE cukid; |
609 |
int br, sgn; |
610 |
|
611 |
cukid.cusize = cu->cusize * 0.5; /* find subcube */ |
612 |
VCOPY(cukid.cuorg, cu->cuorg); |
613 |
br = 0; |
614 |
if (pos[0] >= cukid.cuorg[0]+cukid.cusize) { |
615 |
cukid.cuorg[0] += cukid.cusize; |
616 |
br |= 1; |
617 |
} |
618 |
if (pos[1] >= cukid.cuorg[1]+cukid.cusize) { |
619 |
cukid.cuorg[1] += cukid.cusize; |
620 |
br |= 2; |
621 |
} |
622 |
if (pos[2] >= cukid.cuorg[2]+cukid.cusize) { |
623 |
cukid.cuorg[2] += cukid.cusize; |
624 |
br |= 4; |
625 |
} |
626 |
for ( ; ; ) { |
627 |
cukid.cutree = octkid(cu->cutree, br); |
628 |
if ((ax = raymove(pos,cxs,dirf,r,&cukid)) == RAYHIT) |
629 |
return(RAYHIT); |
630 |
sgn = 1 << ax; |
631 |
if (sgn & dirf) /* positive axis? */ |
632 |
if (sgn & br) |
633 |
return(ax); /* overflow */ |
634 |
else { |
635 |
cukid.cuorg[ax] += cukid.cusize; |
636 |
br |= sgn; |
637 |
} |
638 |
else |
639 |
if (sgn & br) { |
640 |
cukid.cuorg[ax] -= cukid.cusize; |
641 |
br &= ~sgn; |
642 |
} else |
643 |
return(ax); /* underflow */ |
644 |
} |
645 |
/*NOTREACHED*/ |
646 |
} |
647 |
if (isfull(cu->cutree)) { |
648 |
if (checkhit(r, cu, cxs)) |
649 |
return(RAYHIT); |
650 |
} else if (r->ro == &Aftplane && incube(cu, r->rop)) |
651 |
return(RAYHIT); |
652 |
/* advance to next cube */ |
653 |
if (dirf&0x11) { |
654 |
dt = dirf&1 ? cu->cuorg[0] + cu->cusize : cu->cuorg[0]; |
655 |
t = (dt - pos[0])/r->rdir[0]; |
656 |
ax = 0; |
657 |
} else |
658 |
t = FHUGE; |
659 |
if (dirf&0x22) { |
660 |
dt = dirf&2 ? cu->cuorg[1] + cu->cusize : cu->cuorg[1]; |
661 |
dt = (dt - pos[1])/r->rdir[1]; |
662 |
if (dt < t) { |
663 |
t = dt; |
664 |
ax = 1; |
665 |
} |
666 |
} |
667 |
if (dirf&0x44) { |
668 |
dt = dirf&4 ? cu->cuorg[2] + cu->cusize : cu->cuorg[2]; |
669 |
dt = (dt - pos[2])/r->rdir[2]; |
670 |
if (dt < t) { |
671 |
t = dt; |
672 |
ax = 2; |
673 |
} |
674 |
} |
675 |
VSUM(pos, pos, r->rdir, t); |
676 |
return(ax); |
677 |
} |
678 |
|
679 |
|
680 |
static int |
681 |
checkhit( /* check for hit in full cube */ |
682 |
RAY *r, |
683 |
CUBE *cu, |
684 |
OBJECT *cxs |
685 |
) |
686 |
{ |
687 |
OBJECT oset[MAXSET+1]; |
688 |
|
689 |
objset(oset, cu->cutree); |
690 |
checkset(oset, cxs); /* avoid double-checking */ |
691 |
|
692 |
(*r->hitf)(oset, r); /* test for hit in set */ |
693 |
|
694 |
if (r->robj == OVOID) |
695 |
return(0); /* no scores yet */ |
696 |
|
697 |
return(incube(cu, r->rop)); /* hit OK if in current cube */ |
698 |
} |
699 |
|
700 |
|
701 |
static void |
702 |
checkset( /* modify checked set and set to check */ |
703 |
OBJECT *os, /* os' = os - cs */ |
704 |
OBJECT *cs /* cs' = cs + os */ |
705 |
) |
706 |
{ |
707 |
OBJECT cset[MAXCSET+MAXSET+1]; |
708 |
int i, j; |
709 |
int k; |
710 |
/* copy os in place, cset <- cs */ |
711 |
cset[0] = 0; |
712 |
k = 0; |
713 |
for (i = j = 1; i <= os[0]; i++) { |
714 |
while (j <= cs[0] && cs[j] < os[i]) |
715 |
cset[++cset[0]] = cs[j++]; |
716 |
if (j > cs[0] || os[i] != cs[j]) { /* object to check */ |
717 |
os[++k] = os[i]; |
718 |
cset[++cset[0]] = os[i]; |
719 |
} |
720 |
} |
721 |
if (!(os[0] = k)) /* new "to check" set size */ |
722 |
return; /* special case */ |
723 |
while (j <= cs[0]) /* get the rest of cs */ |
724 |
cset[++cset[0]] = cs[j++]; |
725 |
if (cset[0] > MAXCSET) /* truncate "checked" set if nec. */ |
726 |
cset[0] = MAXCSET; |
727 |
/* setcopy(cs, cset); */ /* copy cset back to cs */ |
728 |
os = cset; |
729 |
for (i = os[0]; i-- >= 0; ) |
730 |
*cs++ = *os++; |
731 |
} |