1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: raytrace.c,v 2.44 2003/12/31 01:50:02 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 |
|
17 |
#define MAXCSET ((MAXSET+1)*2-1) /* maximum check set size */ |
18 |
|
19 |
unsigned long raynum = 0; /* next unique ray number */ |
20 |
unsigned long nrays = 0; /* number of calls to localhit */ |
21 |
|
22 |
static RREAL Lambfa[5] = {PI, PI, PI, 0.0, 0.0}; |
23 |
OBJREC Lamb = { |
24 |
OVOID, MAT_PLASTIC, "Lambertian", |
25 |
{0, 5, NULL, Lambfa}, NULL, |
26 |
}; /* a Lambertian surface */ |
27 |
|
28 |
OBJREC Aftplane; /* aft clipping plane object */ |
29 |
|
30 |
#define RAYHIT (-1) /* return value for intercepted ray */ |
31 |
|
32 |
static int raymove(FVECT pos, OBJECT *cxs, int dirf, RAY *r, CUBE *cu); |
33 |
static int checkhit(RAY *r, CUBE *cu, OBJECT *cxs); |
34 |
static void checkset(OBJECT *os, OBJECT *cs); |
35 |
|
36 |
|
37 |
extern int |
38 |
rayorigin( /* start new ray from old one */ |
39 |
register RAY *r, |
40 |
register RAY *ro, |
41 |
int rt, |
42 |
double rw |
43 |
) |
44 |
{ |
45 |
double re; |
46 |
|
47 |
if ((r->parent = ro) == NULL) { /* primary ray */ |
48 |
r->rlvl = 0; |
49 |
r->rweight = rw; |
50 |
r->crtype = r->rtype = rt; |
51 |
r->rsrc = -1; |
52 |
r->clipset = NULL; |
53 |
r->revf = raytrace; |
54 |
copycolor(r->cext, cextinction); |
55 |
copycolor(r->albedo, salbedo); |
56 |
r->gecc = seccg; |
57 |
r->slights = NULL; |
58 |
} else { /* spawned ray */ |
59 |
r->rlvl = ro->rlvl; |
60 |
if (rt & RAYREFL) { |
61 |
r->rlvl++; |
62 |
r->rsrc = -1; |
63 |
r->clipset = ro->clipset; |
64 |
r->rmax = 0.0; |
65 |
} else { |
66 |
r->rsrc = ro->rsrc; |
67 |
r->clipset = ro->newcset; |
68 |
r->rmax = ro->rmax <= FTINY ? 0.0 : ro->rmax - ro->rot; |
69 |
} |
70 |
r->revf = ro->revf; |
71 |
copycolor(r->cext, ro->cext); |
72 |
copycolor(r->albedo, ro->albedo); |
73 |
r->gecc = ro->gecc; |
74 |
r->slights = ro->slights; |
75 |
r->crtype = ro->crtype | (r->rtype = rt); |
76 |
VCOPY(r->rorg, ro->rop); |
77 |
r->rweight = ro->rweight * rw; |
78 |
/* estimate absorption */ |
79 |
re = colval(ro->cext,RED) < colval(ro->cext,GRN) ? |
80 |
colval(ro->cext,RED) : colval(ro->cext,GRN); |
81 |
if (colval(ro->cext,BLU) < re) re = colval(ro->cext,BLU); |
82 |
if (re > 0.) |
83 |
r->rweight *= exp(-re*ro->rot); |
84 |
} |
85 |
rayclear(r); |
86 |
return(r->rlvl <= maxdepth && r->rweight >= minweight ? 0 : -1); |
87 |
} |
88 |
|
89 |
|
90 |
extern void |
91 |
rayclear( /* clear a ray for (re)evaluation */ |
92 |
register RAY *r |
93 |
) |
94 |
{ |
95 |
r->rno = raynum++; |
96 |
r->newcset = r->clipset; |
97 |
r->hitf = rayhit; |
98 |
r->robj = OVOID; |
99 |
r->ro = NULL; |
100 |
r->rox = NULL; |
101 |
r->rt = r->rot = FHUGE; |
102 |
r->pert[0] = r->pert[1] = r->pert[2] = 0.0; |
103 |
r->uv[0] = r->uv[1] = 0.0; |
104 |
setcolor(r->pcol, 1.0, 1.0, 1.0); |
105 |
setcolor(r->rcol, 0.0, 0.0, 0.0); |
106 |
} |
107 |
|
108 |
|
109 |
extern void |
110 |
raytrace( /* trace a ray and compute its value */ |
111 |
RAY *r |
112 |
) |
113 |
{ |
114 |
if (localhit(r, &thescene)) |
115 |
raycont(r); /* hit local surface, evaluate */ |
116 |
else if (r->ro == &Aftplane) { |
117 |
r->ro = NULL; /* hit aft clipping plane */ |
118 |
r->rot = FHUGE; |
119 |
} else if (sourcehit(r)) |
120 |
rayshade(r, r->ro->omod); /* distant source */ |
121 |
|
122 |
rayparticipate(r); /* for participating medium */ |
123 |
|
124 |
if (trace != NULL) |
125 |
(*trace)(r); /* trace execution */ |
126 |
} |
127 |
|
128 |
|
129 |
extern void |
130 |
raycont( /* check for clipped object and continue */ |
131 |
register RAY *r |
132 |
) |
133 |
{ |
134 |
if ((r->clipset != NULL && inset(r->clipset, r->ro->omod)) || |
135 |
!rayshade(r, r->ro->omod)) |
136 |
raytrans(r); |
137 |
} |
138 |
|
139 |
|
140 |
extern void |
141 |
raytrans( /* transmit ray as is */ |
142 |
register RAY *r |
143 |
) |
144 |
{ |
145 |
RAY tr; |
146 |
|
147 |
if (rayorigin(&tr, r, TRANS, 1.0) == 0) { |
148 |
VCOPY(tr.rdir, r->rdir); |
149 |
rayvalue(&tr); |
150 |
copycolor(r->rcol, tr.rcol); |
151 |
r->rt = r->rot + tr.rt; |
152 |
} |
153 |
} |
154 |
|
155 |
|
156 |
extern int |
157 |
rayshade( /* shade ray r with material mod */ |
158 |
register RAY *r, |
159 |
int mod |
160 |
) |
161 |
{ |
162 |
int gotmat; |
163 |
register OBJREC *m; |
164 |
r->rt = r->rot; /* set effective ray length */ |
165 |
for (gotmat = 0; !gotmat && mod != OVOID; mod = m->omod) { |
166 |
m = objptr(mod); |
167 |
/****** unnecessary test since modifier() is always called |
168 |
if (!ismodifier(m->otype)) { |
169 |
sprintf(errmsg, "illegal modifier \"%s\"", m->oname); |
170 |
error(USER, errmsg); |
171 |
} |
172 |
******/ |
173 |
/* hack for irradiance calculation */ |
174 |
if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS)) && |
175 |
m->otype != MAT_CLIP && |
176 |
(ofun[m->otype].flags & (T_M|T_X))) { |
177 |
if (irr_ignore(m->otype)) { |
178 |
raytrans(r); |
179 |
return(1); |
180 |
} |
181 |
if (!islight(m->otype)) |
182 |
m = &Lamb; |
183 |
} |
184 |
/* materials call raytexture */ |
185 |
gotmat = (*ofun[m->otype].funp)(m, r); |
186 |
} |
187 |
return(gotmat); |
188 |
} |
189 |
|
190 |
|
191 |
extern void |
192 |
rayparticipate( /* compute ray medium participation */ |
193 |
register RAY *r |
194 |
) |
195 |
{ |
196 |
COLOR ce, ca; |
197 |
double re, ge, be; |
198 |
|
199 |
if (intens(r->cext) <= 1./FHUGE) |
200 |
return; /* no medium */ |
201 |
re = r->rot*colval(r->cext,RED); |
202 |
ge = r->rot*colval(r->cext,GRN); |
203 |
be = r->rot*colval(r->cext,BLU); |
204 |
if (r->crtype & SHADOW) { /* no scattering for sources */ |
205 |
re *= 1. - colval(r->albedo,RED); |
206 |
ge *= 1. - colval(r->albedo,GRN); |
207 |
be *= 1. - colval(r->albedo,BLU); |
208 |
} |
209 |
setcolor(ce, re<=0. ? 1. : re>92. ? 0. : exp(-re), |
210 |
ge<=0. ? 1. : ge>92. ? 0. : exp(-ge), |
211 |
be<=0. ? 1. : be>92. ? 0. : exp(-be)); |
212 |
multcolor(r->rcol, ce); /* path absorption */ |
213 |
if (r->crtype & SHADOW || intens(r->albedo) <= FTINY) |
214 |
return; /* no scattering */ |
215 |
setcolor(ca, |
216 |
colval(r->albedo,RED)*colval(ambval,RED)*(1.-colval(ce,RED)), |
217 |
colval(r->albedo,GRN)*colval(ambval,GRN)*(1.-colval(ce,GRN)), |
218 |
colval(r->albedo,BLU)*colval(ambval,BLU)*(1.-colval(ce,BLU))); |
219 |
addcolor(r->rcol, ca); /* ambient in scattering */ |
220 |
srcscatter(r); /* source in scattering */ |
221 |
} |
222 |
|
223 |
|
224 |
extern void |
225 |
raytexture( /* get material modifiers */ |
226 |
RAY *r, |
227 |
OBJECT mod |
228 |
) |
229 |
{ |
230 |
register OBJREC *m; |
231 |
/* execute textures and patterns */ |
232 |
for ( ; mod != OVOID; mod = m->omod) { |
233 |
m = objptr(mod); |
234 |
/****** unnecessary test since modifier() is always called |
235 |
if (!ismodifier(m->otype)) { |
236 |
sprintf(errmsg, "illegal modifier \"%s\"", m->oname); |
237 |
error(USER, errmsg); |
238 |
} |
239 |
******/ |
240 |
if ((*ofun[m->otype].funp)(m, r)) { |
241 |
sprintf(errmsg, "conflicting material \"%s\"", |
242 |
m->oname); |
243 |
objerror(r->ro, USER, errmsg); |
244 |
} |
245 |
} |
246 |
} |
247 |
|
248 |
|
249 |
extern int |
250 |
raymixture( /* mix modifiers */ |
251 |
register RAY *r, |
252 |
OBJECT fore, |
253 |
OBJECT back, |
254 |
double coef |
255 |
) |
256 |
{ |
257 |
RAY fr, br; |
258 |
int foremat, backmat; |
259 |
register int i; |
260 |
/* bound coefficient */ |
261 |
if (coef > 1.0) |
262 |
coef = 1.0; |
263 |
else if (coef < 0.0) |
264 |
coef = 0.0; |
265 |
/* compute foreground and background */ |
266 |
foremat = backmat = 0; |
267 |
/* foreground */ |
268 |
fr = *r; |
269 |
if (coef > FTINY) |
270 |
foremat = rayshade(&fr, fore); |
271 |
/* background */ |
272 |
br = *r; |
273 |
if (coef < 1.0-FTINY) |
274 |
backmat = rayshade(&br, back); |
275 |
/* check for transparency */ |
276 |
if (backmat ^ foremat) { |
277 |
if (backmat && coef > FTINY) |
278 |
raytrans(&fr); |
279 |
else if (foremat && coef < 1.0-FTINY) |
280 |
raytrans(&br); |
281 |
} |
282 |
/* mix perturbations */ |
283 |
for (i = 0; i < 3; i++) |
284 |
r->pert[i] = coef*fr.pert[i] + (1.0-coef)*br.pert[i]; |
285 |
/* mix pattern colors */ |
286 |
scalecolor(fr.pcol, coef); |
287 |
scalecolor(br.pcol, 1.0-coef); |
288 |
copycolor(r->pcol, fr.pcol); |
289 |
addcolor(r->pcol, br.pcol); |
290 |
/* return value tells if material */ |
291 |
if (!foremat & !backmat) |
292 |
return(0); |
293 |
/* mix returned ray values */ |
294 |
scalecolor(fr.rcol, coef); |
295 |
scalecolor(br.rcol, 1.0-coef); |
296 |
copycolor(r->rcol, fr.rcol); |
297 |
addcolor(r->rcol, br.rcol); |
298 |
r->rt = bright(fr.rcol) > bright(br.rcol) ? fr.rt : br.rt; |
299 |
return(1); |
300 |
} |
301 |
|
302 |
|
303 |
extern double |
304 |
raydist( /* compute (cumulative) ray distance */ |
305 |
register RAY *r, |
306 |
register int flags |
307 |
) |
308 |
{ |
309 |
double sum = 0.0; |
310 |
|
311 |
while (r != NULL && r->crtype&flags) { |
312 |
sum += r->rot; |
313 |
r = r->parent; |
314 |
} |
315 |
return(sum); |
316 |
} |
317 |
|
318 |
|
319 |
extern double |
320 |
raynormal( /* compute perturbed normal for ray */ |
321 |
FVECT norm, |
322 |
register RAY *r |
323 |
) |
324 |
{ |
325 |
double newdot; |
326 |
register int i; |
327 |
|
328 |
/* The perturbation is added to the surface normal to obtain |
329 |
* the new normal. If the new normal would affect the surface |
330 |
* orientation wrt. the ray, a correction is made. The method is |
331 |
* still fraught with problems since reflected rays and similar |
332 |
* directions calculated from the surface normal may spawn rays behind |
333 |
* the surface. The only solution is to curb textures at high |
334 |
* incidence (namely, keep DOT(rdir,pert) < Rdot). |
335 |
*/ |
336 |
|
337 |
for (i = 0; i < 3; i++) |
338 |
norm[i] = r->ron[i] + r->pert[i]; |
339 |
|
340 |
if (normalize(norm) == 0.0) { |
341 |
objerror(r->ro, WARNING, "illegal normal perturbation"); |
342 |
VCOPY(norm, r->ron); |
343 |
return(r->rod); |
344 |
} |
345 |
newdot = -DOT(norm, r->rdir); |
346 |
if ((newdot > 0.0) != (r->rod > 0.0)) { /* fix orientation */ |
347 |
for (i = 0; i < 3; i++) |
348 |
norm[i] += 2.0*newdot*r->rdir[i]; |
349 |
newdot = -newdot; |
350 |
} |
351 |
return(newdot); |
352 |
} |
353 |
|
354 |
|
355 |
extern void |
356 |
newrayxf( /* get new tranformation matrix for ray */ |
357 |
RAY *r |
358 |
) |
359 |
{ |
360 |
static struct xfn { |
361 |
struct xfn *next; |
362 |
FULLXF xf; |
363 |
} xfseed = { &xfseed }, *xflast = &xfseed; |
364 |
register struct xfn *xp; |
365 |
register RAY *rp; |
366 |
|
367 |
/* |
368 |
* Search for transform in circular list that |
369 |
* has no associated ray in the tree. |
370 |
*/ |
371 |
xp = xflast; |
372 |
for (rp = r->parent; rp != NULL; rp = rp->parent) |
373 |
if (rp->rox == &xp->xf) { /* xp in use */ |
374 |
xp = xp->next; /* move to next */ |
375 |
if (xp == xflast) { /* need new one */ |
376 |
xp = (struct xfn *)malloc(sizeof(struct xfn)); |
377 |
if (xp == NULL) |
378 |
error(SYSTEM, |
379 |
"out of memory in newrayxf"); |
380 |
/* insert in list */ |
381 |
xp->next = xflast->next; |
382 |
xflast->next = xp; |
383 |
break; /* we're done */ |
384 |
} |
385 |
rp = r; /* start check over */ |
386 |
} |
387 |
/* got it */ |
388 |
r->rox = &xp->xf; |
389 |
xflast = xp; |
390 |
} |
391 |
|
392 |
|
393 |
extern void |
394 |
flipsurface( /* reverse surface orientation */ |
395 |
register RAY *r |
396 |
) |
397 |
{ |
398 |
r->rod = -r->rod; |
399 |
r->ron[0] = -r->ron[0]; |
400 |
r->ron[1] = -r->ron[1]; |
401 |
r->ron[2] = -r->ron[2]; |
402 |
r->pert[0] = -r->pert[0]; |
403 |
r->pert[1] = -r->pert[1]; |
404 |
r->pert[2] = -r->pert[2]; |
405 |
} |
406 |
|
407 |
|
408 |
extern void |
409 |
rayhit( /* standard ray hit test */ |
410 |
OBJECT *oset, |
411 |
RAY *r |
412 |
) |
413 |
{ |
414 |
OBJREC *o; |
415 |
int i; |
416 |
|
417 |
for (i = oset[0]; i > 0; i--) { |
418 |
o = objptr(oset[i]); |
419 |
if ((*ofun[o->otype].funp)(o, r)) |
420 |
r->robj = oset[i]; |
421 |
} |
422 |
} |
423 |
|
424 |
|
425 |
extern int |
426 |
localhit( /* check for hit in the octree */ |
427 |
register RAY *r, |
428 |
register CUBE *scene |
429 |
) |
430 |
{ |
431 |
OBJECT cxset[MAXCSET+1]; /* set of checked objects */ |
432 |
FVECT curpos; /* current cube position */ |
433 |
int sflags; /* sign flags */ |
434 |
double t, dt; |
435 |
register int i; |
436 |
|
437 |
nrays++; /* increment trace counter */ |
438 |
sflags = 0; |
439 |
for (i = 0; i < 3; i++) { |
440 |
curpos[i] = r->rorg[i]; |
441 |
if (r->rdir[i] > 1e-7) |
442 |
sflags |= 1 << i; |
443 |
else if (r->rdir[i] < -1e-7) |
444 |
sflags |= 0x10 << i; |
445 |
} |
446 |
if (sflags == 0) |
447 |
error(CONSISTENCY, "zero ray direction in localhit"); |
448 |
/* start off assuming nothing hit */ |
449 |
if (r->rmax > FTINY) { /* except aft plane if one */ |
450 |
r->ro = &Aftplane; |
451 |
r->rot = r->rmax; |
452 |
for (i = 0; i < 3; i++) |
453 |
r->rop[i] = r->rorg[i] + r->rot*r->rdir[i]; |
454 |
} |
455 |
/* find global cube entrance point */ |
456 |
t = 0.0; |
457 |
if (!incube(scene, curpos)) { |
458 |
/* find distance to entry */ |
459 |
for (i = 0; i < 3; i++) { |
460 |
/* plane in our direction */ |
461 |
if (sflags & 1<<i) |
462 |
dt = scene->cuorg[i]; |
463 |
else if (sflags & 0x10<<i) |
464 |
dt = scene->cuorg[i] + scene->cusize; |
465 |
else |
466 |
continue; |
467 |
/* distance to the plane */ |
468 |
dt = (dt - r->rorg[i])/r->rdir[i]; |
469 |
if (dt > t) |
470 |
t = dt; /* farthest face is the one */ |
471 |
} |
472 |
t += FTINY; /* fudge to get inside cube */ |
473 |
if (t >= r->rot) /* clipped already */ |
474 |
return(0); |
475 |
/* advance position */ |
476 |
for (i = 0; i < 3; i++) |
477 |
curpos[i] += r->rdir[i]*t; |
478 |
|
479 |
if (!incube(scene, curpos)) /* non-intersecting ray */ |
480 |
return(0); |
481 |
} |
482 |
cxset[0] = 0; |
483 |
raymove(curpos, cxset, sflags, r, scene); |
484 |
return((r->ro != NULL) & (r->ro != &Aftplane)); |
485 |
} |
486 |
|
487 |
|
488 |
static int |
489 |
raymove( /* check for hit as we move */ |
490 |
FVECT pos, /* current position, modified herein */ |
491 |
OBJECT *cxs, /* checked objects, modified by checkhit */ |
492 |
int dirf, /* direction indicators to speed tests */ |
493 |
register RAY *r, |
494 |
register CUBE *cu |
495 |
) |
496 |
{ |
497 |
int ax; |
498 |
double dt, t; |
499 |
|
500 |
if (istree(cu->cutree)) { /* recurse on subcubes */ |
501 |
CUBE cukid; |
502 |
register int br, sgn; |
503 |
|
504 |
cukid.cusize = cu->cusize * 0.5; /* find subcube */ |
505 |
VCOPY(cukid.cuorg, cu->cuorg); |
506 |
br = 0; |
507 |
if (pos[0] >= cukid.cuorg[0]+cukid.cusize) { |
508 |
cukid.cuorg[0] += cukid.cusize; |
509 |
br |= 1; |
510 |
} |
511 |
if (pos[1] >= cukid.cuorg[1]+cukid.cusize) { |
512 |
cukid.cuorg[1] += cukid.cusize; |
513 |
br |= 2; |
514 |
} |
515 |
if (pos[2] >= cukid.cuorg[2]+cukid.cusize) { |
516 |
cukid.cuorg[2] += cukid.cusize; |
517 |
br |= 4; |
518 |
} |
519 |
for ( ; ; ) { |
520 |
cukid.cutree = octkid(cu->cutree, br); |
521 |
if ((ax = raymove(pos,cxs,dirf,r,&cukid)) == RAYHIT) |
522 |
return(RAYHIT); |
523 |
sgn = 1 << ax; |
524 |
if (sgn & dirf) /* positive axis? */ |
525 |
if (sgn & br) |
526 |
return(ax); /* overflow */ |
527 |
else { |
528 |
cukid.cuorg[ax] += cukid.cusize; |
529 |
br |= sgn; |
530 |
} |
531 |
else |
532 |
if (sgn & br) { |
533 |
cukid.cuorg[ax] -= cukid.cusize; |
534 |
br &= ~sgn; |
535 |
} else |
536 |
return(ax); /* underflow */ |
537 |
} |
538 |
/*NOTREACHED*/ |
539 |
} |
540 |
if (isfull(cu->cutree)) { |
541 |
if (checkhit(r, cu, cxs)) |
542 |
return(RAYHIT); |
543 |
} else if (r->ro == &Aftplane && incube(cu, r->rop)) |
544 |
return(RAYHIT); |
545 |
/* advance to next cube */ |
546 |
if (dirf&0x11) { |
547 |
dt = dirf&1 ? cu->cuorg[0] + cu->cusize : cu->cuorg[0]; |
548 |
t = (dt - pos[0])/r->rdir[0]; |
549 |
ax = 0; |
550 |
} else |
551 |
t = FHUGE; |
552 |
if (dirf&0x22) { |
553 |
dt = dirf&2 ? cu->cuorg[1] + cu->cusize : cu->cuorg[1]; |
554 |
dt = (dt - pos[1])/r->rdir[1]; |
555 |
if (dt < t) { |
556 |
t = dt; |
557 |
ax = 1; |
558 |
} |
559 |
} |
560 |
if (dirf&0x44) { |
561 |
dt = dirf&4 ? cu->cuorg[2] + cu->cusize : cu->cuorg[2]; |
562 |
dt = (dt - pos[2])/r->rdir[2]; |
563 |
if (dt < t) { |
564 |
t = dt; |
565 |
ax = 2; |
566 |
} |
567 |
} |
568 |
pos[0] += r->rdir[0]*t; |
569 |
pos[1] += r->rdir[1]*t; |
570 |
pos[2] += r->rdir[2]*t; |
571 |
return(ax); |
572 |
} |
573 |
|
574 |
|
575 |
static int |
576 |
checkhit( /* check for hit in full cube */ |
577 |
register RAY *r, |
578 |
CUBE *cu, |
579 |
OBJECT *cxs |
580 |
) |
581 |
{ |
582 |
OBJECT oset[MAXSET+1]; |
583 |
|
584 |
objset(oset, cu->cutree); |
585 |
checkset(oset, cxs); /* avoid double-checking */ |
586 |
|
587 |
(*r->hitf)(oset, r); /* test for hit in set */ |
588 |
|
589 |
if (r->robj == OVOID) |
590 |
return(0); /* no scores yet */ |
591 |
|
592 |
return(incube(cu, r->rop)); /* hit OK if in current cube */ |
593 |
} |
594 |
|
595 |
|
596 |
static void |
597 |
checkset( /* modify checked set and set to check */ |
598 |
register OBJECT *os, /* os' = os - cs */ |
599 |
register OBJECT *cs /* cs' = cs + os */ |
600 |
) |
601 |
{ |
602 |
OBJECT cset[MAXCSET+MAXSET+1]; |
603 |
register int i, j; |
604 |
int k; |
605 |
/* copy os in place, cset <- cs */ |
606 |
cset[0] = 0; |
607 |
k = 0; |
608 |
for (i = j = 1; i <= os[0]; i++) { |
609 |
while (j <= cs[0] && cs[j] < os[i]) |
610 |
cset[++cset[0]] = cs[j++]; |
611 |
if (j > cs[0] || os[i] != cs[j]) { /* object to check */ |
612 |
os[++k] = os[i]; |
613 |
cset[++cset[0]] = os[i]; |
614 |
} |
615 |
} |
616 |
if (!(os[0] = k)) /* new "to check" set size */ |
617 |
return; /* special case */ |
618 |
while (j <= cs[0]) /* get the rest of cs */ |
619 |
cset[++cset[0]] = cs[j++]; |
620 |
if (cset[0] > MAXCSET) /* truncate "checked" set if nec. */ |
621 |
cset[0] = MAXCSET; |
622 |
/* setcopy(cs, cset); */ /* copy cset back to cs */ |
623 |
os = cset; |
624 |
for (i = os[0]; i-- >= 0; ) |
625 |
*cs++ = *os++; |
626 |
} |