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#ifndef lint |
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static const char RCSid[] = "$Id$"; |
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static const char RCSid[] = "$Id$"; |
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#endif |
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/* |
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* raytrace.c - routines for tracing and shading rays. |
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#include "copyright.h" |
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#include "ray.h" |
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|
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#include "source.h" |
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#include "otypes.h" |
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|
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#include "otspecial.h" |
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#include "random.h" |
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#define MAXCSET ((MAXSET+1)*2-1) /* maximum check set size */ |
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|
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unsigned long raynum = 0; /* next unique ray number */ |
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unsigned long nrays = 0; /* number of calls to localhit */ |
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|
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static FLOAT Lambfa[5] = {PI, PI, PI, 0.0, 0.0}; |
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static RREAL Lambfa[5] = {PI, PI, PI, 0.0, 0.0}; |
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OBJREC Lamb = { |
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OVOID, MAT_PLASTIC, "Lambertian", |
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{0, 5, NULL, Lambfa}, NULL, |
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|
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OBJREC Aftplane; /* aft clipping plane object */ |
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|
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static int raymove(), checkhit(); |
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static void checkset(); |
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|
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#ifndef MAXLOOP |
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#define MAXLOOP 0 /* modifier loop detection */ |
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#endif |
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|
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#define RAYHIT (-1) /* return value for intercepted ray */ |
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static int raymove(FVECT pos, OBJECT *cxs, int dirf, RAY *r, CUBE *cu); |
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static int checkhit(RAY *r, CUBE *cu, OBJECT *cxs); |
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static void checkset(OBJECT *os, OBJECT *cs); |
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|
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int |
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rayorigin(r, ro, rt, rw) /* start new ray from old one */ |
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register RAY *r, *ro; |
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int rt; |
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double rw; |
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{ |
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double re; |
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|
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extern int |
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rayorigin( /* start new ray from old one */ |
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RAY *r, |
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int rt, |
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const RAY *ro, |
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const COLOR rc |
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) |
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{ |
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double rw, re; |
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/* assign coefficient/weight */ |
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if (rc == NULL) { |
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rw = 1.0; |
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setcolor(r->rcoef, 1., 1., 1.); |
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} else { |
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rw = intens(rc); |
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if (rc != r->rcoef) |
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copycolor(r->rcoef, rc); |
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} |
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if ((r->parent = ro) == NULL) { /* primary ray */ |
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r->rlvl = 0; |
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r->rweight = rw; |
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r->gecc = seccg; |
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r->slights = NULL; |
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} else { /* spawned ray */ |
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if (ro->rot >= FHUGE) { |
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memset(r, 0, sizeof(RAY)); |
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return(-1); /* illegal continuation */ |
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} |
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r->rlvl = ro->rlvl; |
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if (rt & RAYREFL) { |
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r->rlvl++; |
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r->crtype = ro->crtype | (r->rtype = rt); |
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VCOPY(r->rorg, ro->rop); |
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r->rweight = ro->rweight * rw; |
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/* estimate absorption */ |
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/* estimate extinction */ |
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re = colval(ro->cext,RED) < colval(ro->cext,GRN) ? |
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colval(ro->cext,RED) : colval(ro->cext,GRN); |
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if (colval(ro->cext,BLU) < re) re = colval(ro->cext,BLU); |
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if (re > 0.) |
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r->rweight *= exp(-re*ro->rot); |
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re *= ro->rot; |
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if (re > .1) |
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r->rweight *= exp(-re); |
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} |
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rayclear(r); |
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if (maxdepth <= 0 && rc != NULL) { /* Russian roulette */ |
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if (minweight <= 0.0) |
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error(USER, "zero ray weight in Russian roulette"); |
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if (maxdepth < 0 && r->rlvl > -maxdepth) |
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return(-1); /* upper reflection limit */ |
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if (r->rweight >= minweight) |
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return(0); |
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if (frandom() < r->rweight/minweight) |
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return(-1); |
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rw = minweight/r->rweight; /* promote survivor */ |
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scalecolor(r->rcoef, rw); |
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r->rweight = minweight; |
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return(0); |
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} |
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return(r->rlvl <= maxdepth && r->rweight >= minweight ? 0 : -1); |
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} |
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|
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void |
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rayclear(r) /* clear a ray for (re)evaluation */ |
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register RAY *r; |
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extern void |
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rayclear( /* clear a ray for (re)evaluation */ |
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register RAY *r |
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) |
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{ |
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r->rno = raynum++; |
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r->newcset = r->clipset; |
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r->hitf = rayhit; |
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r->robj = OVOID; |
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r->ro = NULL; |
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r->rox = NULL; |
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r->rt = r->rot = FHUGE; |
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r->pert[0] = r->pert[1] = r->pert[2] = 0.0; |
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r->uv[0] = r->uv[1] = 0.0; |
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setcolor(r->pcol, 1.0, 1.0, 1.0); |
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setcolor(r->rcol, 0.0, 0.0, 0.0); |
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} |
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void |
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raytrace(r) /* trace a ray and compute its value */ |
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RAY *r; |
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extern void |
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raytrace( /* trace a ray and compute its value */ |
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RAY *r |
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) |
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{ |
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if (localhit(r, &thescene)) |
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raycont(r); /* hit local surface, evaluate */ |
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} else if (sourcehit(r)) |
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rayshade(r, r->ro->omod); /* distant source */ |
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|
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rayparticipate(r); /* for participating medium */ |
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|
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if (trace != NULL) |
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(*trace)(r); /* trace execution */ |
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|
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rayparticipate(r); /* for participating medium */ |
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} |
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|
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void |
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raycont(r) /* check for clipped object and continue */ |
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register RAY *r; |
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extern void |
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raycont( /* check for clipped object and continue */ |
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register RAY *r |
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) |
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{ |
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if ((r->clipset != NULL && inset(r->clipset, r->ro->omod)) || |
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!rayshade(r, r->ro->omod)) |
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} |
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|
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void |
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raytrans(r) /* transmit ray as is */ |
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register RAY *r; |
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extern void |
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raytrans( /* transmit ray as is */ |
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register RAY *r |
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) |
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{ |
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RAY tr; |
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|
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if (rayorigin(&tr, r, TRANS, 1.0) == 0) { |
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if (rayorigin(&tr, TRANS, r, NULL) == 0) { |
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VCOPY(tr.rdir, r->rdir); |
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rayvalue(&tr); |
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copycolor(r->rcol, tr.rcol); |
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} |
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|
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int |
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rayshade(r, mod) /* shade ray r with material mod */ |
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register RAY *r; |
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int mod; |
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extern int |
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rayshade( /* shade ray r with material mod */ |
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register RAY *r, |
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int mod |
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) |
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{ |
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int gotmat; |
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register OBJREC *m; |
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#if MAXLOOP |
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static int depth = 0; |
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/* check for infinite loop */ |
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if (depth++ >= MAXLOOP) |
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objerror(r->ro, USER, "possible modifier loop"); |
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#endif |
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|
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r->rt = r->rot; /* set effective ray length */ |
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for (gotmat = 0; !gotmat && mod != OVOID; mod = m->omod) { |
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for ( ; mod != OVOID; mod = m->omod) { |
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m = objptr(mod); |
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/****** unnecessary test since modifier() is always called |
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if (!ismodifier(m->otype)) { |
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} |
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******/ |
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/* hack for irradiance calculation */ |
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if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS))) { |
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if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS)) && |
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m->otype != MAT_CLIP && |
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(ofun[m->otype].flags & (T_M|T_X))) { |
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if (irr_ignore(m->otype)) { |
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#if MAXLOOP |
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depth--; |
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#endif |
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raytrans(r); |
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return(1); |
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} |
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if (!islight(m->otype)) |
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m = &Lamb; |
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} |
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/* materials call raytexture */ |
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gotmat = (*ofun[m->otype].funp)(m, r); |
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if ((*ofun[m->otype].funp)(m, r)) |
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return(1); /* materials call raytexture() */ |
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} |
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#if MAXLOOP |
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depth--; |
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#endif |
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return(gotmat); |
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return(0); /* no material! */ |
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} |
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|
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void |
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rayparticipate(r) /* compute ray medium participation */ |
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register RAY *r; |
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extern void |
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rayparticipate( /* compute ray medium participation */ |
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register RAY *r |
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) |
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{ |
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COLOR ce, ca; |
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double re, ge, be; |
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ge *= 1. - colval(r->albedo,GRN); |
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be *= 1. - colval(r->albedo,BLU); |
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} |
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setcolor(ce, re<=0. ? 1. : re>92. ? 0. : exp(-re), |
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ge<=0. ? 1. : ge>92. ? 0. : exp(-ge), |
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be<=0. ? 1. : be>92. ? 0. : exp(-be)); |
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multcolor(r->rcol, ce); /* path absorption */ |
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setcolor(ce, re<=FTINY ? 1. : re>92. ? 0. : exp(-re), |
238 |
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ge<=FTINY ? 1. : ge>92. ? 0. : exp(-ge), |
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be<=FTINY ? 1. : be>92. ? 0. : exp(-be)); |
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multcolor(r->rcol, ce); /* path extinction */ |
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if (r->crtype & SHADOW || intens(r->albedo) <= FTINY) |
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return; /* no scattering */ |
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setcolor(ca, |
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} |
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|
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|
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raytexture(r, mod) /* get material modifiers */ |
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RAY *r; |
254 |
< |
int mod; |
252 |
> |
extern void |
253 |
> |
raytexture( /* get material modifiers */ |
254 |
> |
RAY *r, |
255 |
> |
OBJECT mod |
256 |
> |
) |
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{ |
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register OBJREC *m; |
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#if MAXLOOP |
234 |
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static int depth = 0; |
235 |
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/* check for infinite loop */ |
236 |
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if (depth++ >= MAXLOOP) |
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objerror(r->ro, USER, "modifier loop"); |
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#endif |
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/* execute textures and patterns */ |
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for ( ; mod != OVOID; mod = m->omod) { |
261 |
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m = objptr(mod); |
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objerror(r->ro, USER, errmsg); |
272 |
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} |
273 |
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} |
254 |
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#if MAXLOOP |
255 |
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depth--; /* end here */ |
256 |
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#endif |
274 |
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} |
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|
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|
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int |
278 |
< |
raymixture(r, fore, back, coef) /* mix modifiers */ |
279 |
< |
register RAY *r; |
280 |
< |
OBJECT fore, back; |
281 |
< |
double coef; |
277 |
> |
extern int |
278 |
> |
raymixture( /* mix modifiers */ |
279 |
> |
register RAY *r, |
280 |
> |
OBJECT fore, |
281 |
> |
OBJECT back, |
282 |
> |
double coef |
283 |
> |
) |
284 |
|
{ |
285 |
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RAY fr, br; |
286 |
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int foremat, backmat; |
293 |
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/* compute foreground and background */ |
294 |
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foremat = backmat = 0; |
295 |
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/* foreground */ |
296 |
< |
copystruct(&fr, r); |
296 |
> |
fr = *r; |
297 |
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if (coef > FTINY) |
298 |
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foremat = rayshade(&fr, fore); |
299 |
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/* background */ |
300 |
< |
copystruct(&br, r); |
300 |
> |
br = *r; |
301 |
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if (coef < 1.0-FTINY) |
302 |
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backmat = rayshade(&br, back); |
303 |
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/* check for transparency */ |
304 |
< |
if (backmat ^ foremat) |
304 |
> |
if (backmat ^ foremat) { |
305 |
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if (backmat && coef > FTINY) |
306 |
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raytrans(&fr); |
307 |
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else if (foremat && coef < 1.0-FTINY) |
308 |
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raytrans(&br); |
309 |
+ |
} |
310 |
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/* mix perturbations */ |
311 |
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for (i = 0; i < 3; i++) |
312 |
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r->pert[i] = coef*fr.pert[i] + (1.0-coef)*br.pert[i]; |
328 |
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} |
329 |
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|
330 |
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|
331 |
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double |
332 |
< |
raydist(r, flags) /* compute (cumulative) ray distance */ |
333 |
< |
register RAY *r; |
334 |
< |
register int flags; |
331 |
> |
extern double |
332 |
> |
raydist( /* compute (cumulative) ray distance */ |
333 |
> |
register const RAY *r, |
334 |
> |
register int flags |
335 |
> |
) |
336 |
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{ |
337 |
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double sum = 0.0; |
338 |
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|
344 |
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} |
345 |
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|
346 |
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|
347 |
< |
double |
348 |
< |
raynormal(norm, r) /* compute perturbed normal for ray */ |
349 |
< |
FVECT norm; |
350 |
< |
register RAY *r; |
347 |
> |
extern void |
348 |
> |
raycontrib( /* compute (cumulative) ray contribution */ |
349 |
> |
COLOR rc, |
350 |
> |
const RAY *r, |
351 |
> |
int flags |
352 |
> |
) |
353 |
|
{ |
354 |
+ |
COLOR eext, ext1; |
355 |
+ |
|
356 |
+ |
setcolor(eext, 0., 0., 0.); |
357 |
+ |
setcolor(rc, 1., 1., 1.); |
358 |
+ |
|
359 |
+ |
while (r != NULL && r->crtype&flags) { |
360 |
+ |
multcolor(rc, r->rcoef); |
361 |
+ |
copycolor(ext1, r->cext); |
362 |
+ |
scalecolor(ext1, r->rot); |
363 |
+ |
addcolor(eext, ext1); |
364 |
+ |
r = r->parent; |
365 |
+ |
} |
366 |
+ |
if (intens(eext) > FTINY) { |
367 |
+ |
setcolor(ext1, exp(-colval(eext,RED)), |
368 |
+ |
exp(-colval(eext,GRN)), |
369 |
+ |
exp(-colval(eext,BLU))); |
370 |
+ |
multcolor(rc, ext1); |
371 |
+ |
} |
372 |
+ |
} |
373 |
+ |
|
374 |
+ |
|
375 |
+ |
extern double |
376 |
+ |
raynormal( /* compute perturbed normal for ray */ |
377 |
+ |
FVECT norm, |
378 |
+ |
register RAY *r |
379 |
+ |
) |
380 |
+ |
{ |
381 |
|
double newdot; |
382 |
|
register int i; |
383 |
|
|
408 |
|
} |
409 |
|
|
410 |
|
|
411 |
< |
void |
412 |
< |
newrayxf(r) /* get new tranformation matrix for ray */ |
413 |
< |
RAY *r; |
411 |
> |
extern void |
412 |
> |
newrayxf( /* get new tranformation matrix for ray */ |
413 |
> |
RAY *r |
414 |
> |
) |
415 |
|
{ |
416 |
|
static struct xfn { |
417 |
|
struct xfn *next; |
418 |
|
FULLXF xf; |
419 |
|
} xfseed = { &xfseed }, *xflast = &xfseed; |
420 |
|
register struct xfn *xp; |
421 |
< |
register RAY *rp; |
421 |
> |
register const RAY *rp; |
422 |
|
|
423 |
|
/* |
424 |
|
* Search for transform in circular list that |
446 |
|
} |
447 |
|
|
448 |
|
|
449 |
< |
void |
450 |
< |
flipsurface(r) /* reverse surface orientation */ |
451 |
< |
register RAY *r; |
449 |
> |
extern void |
450 |
> |
flipsurface( /* reverse surface orientation */ |
451 |
> |
register RAY *r |
452 |
> |
) |
453 |
|
{ |
454 |
|
r->rod = -r->rod; |
455 |
|
r->ron[0] = -r->ron[0]; |
461 |
|
} |
462 |
|
|
463 |
|
|
464 |
< |
int |
465 |
< |
localhit(r, scene) /* check for hit in the octree */ |
466 |
< |
register RAY *r; |
467 |
< |
register CUBE *scene; |
464 |
> |
extern void |
465 |
> |
rayhit( /* standard ray hit test */ |
466 |
> |
OBJECT *oset, |
467 |
> |
RAY *r |
468 |
> |
) |
469 |
|
{ |
470 |
+ |
OBJREC *o; |
471 |
+ |
int i; |
472 |
+ |
|
473 |
+ |
for (i = oset[0]; i > 0; i--) { |
474 |
+ |
o = objptr(oset[i]); |
475 |
+ |
if ((*ofun[o->otype].funp)(o, r)) |
476 |
+ |
r->robj = oset[i]; |
477 |
+ |
} |
478 |
+ |
} |
479 |
+ |
|
480 |
+ |
|
481 |
+ |
extern int |
482 |
+ |
localhit( /* check for hit in the octree */ |
483 |
+ |
register RAY *r, |
484 |
+ |
register CUBE *scene |
485 |
+ |
) |
486 |
+ |
{ |
487 |
|
OBJECT cxset[MAXCSET+1]; /* set of checked objects */ |
488 |
|
FVECT curpos; /* current cube position */ |
489 |
|
int sflags; /* sign flags */ |
537 |
|
} |
538 |
|
cxset[0] = 0; |
539 |
|
raymove(curpos, cxset, sflags, r, scene); |
540 |
< |
return(r->ro != NULL & r->ro != &Aftplane); |
540 |
> |
return((r->ro != NULL) & (r->ro != &Aftplane)); |
541 |
|
} |
542 |
|
|
543 |
|
|
544 |
|
static int |
545 |
< |
raymove(pos, cxs, dirf, r, cu) /* check for hit as we move */ |
546 |
< |
FVECT pos; /* current position, modified herein */ |
547 |
< |
OBJECT *cxs; /* checked objects, modified by checkhit */ |
548 |
< |
int dirf; /* direction indicators to speed tests */ |
549 |
< |
register RAY *r; |
550 |
< |
register CUBE *cu; |
545 |
> |
raymove( /* check for hit as we move */ |
546 |
> |
FVECT pos, /* current position, modified herein */ |
547 |
> |
OBJECT *cxs, /* checked objects, modified by checkhit */ |
548 |
> |
int dirf, /* direction indicators to speed tests */ |
549 |
> |
register RAY *r, |
550 |
> |
register CUBE *cu |
551 |
> |
) |
552 |
|
{ |
553 |
|
int ax; |
554 |
|
double dt, t; |
629 |
|
|
630 |
|
|
631 |
|
static int |
632 |
< |
checkhit(r, cu, cxs) /* check for hit in full cube */ |
633 |
< |
register RAY *r; |
634 |
< |
CUBE *cu; |
635 |
< |
OBJECT *cxs; |
632 |
> |
checkhit( /* check for hit in full cube */ |
633 |
> |
register RAY *r, |
634 |
> |
CUBE *cu, |
635 |
> |
OBJECT *cxs |
636 |
> |
) |
637 |
|
{ |
638 |
|
OBJECT oset[MAXSET+1]; |
567 |
– |
register OBJREC *o; |
568 |
– |
register int i; |
639 |
|
|
640 |
|
objset(oset, cu->cutree); |
641 |
< |
checkset(oset, cxs); /* eliminate double-checking */ |
642 |
< |
for (i = oset[0]; i > 0; i--) { |
643 |
< |
o = objptr(oset[i]); |
644 |
< |
if ((*ofun[o->otype].funp)(o, r)) |
645 |
< |
r->robj = oset[i]; |
576 |
< |
} |
577 |
< |
if (r->ro == NULL) |
641 |
> |
checkset(oset, cxs); /* avoid double-checking */ |
642 |
> |
|
643 |
> |
(*r->hitf)(oset, r); /* test for hit in set */ |
644 |
> |
|
645 |
> |
if (r->robj == OVOID) |
646 |
|
return(0); /* no scores yet */ |
647 |
|
|
648 |
|
return(incube(cu, r->rop)); /* hit OK if in current cube */ |
650 |
|
|
651 |
|
|
652 |
|
static void |
653 |
< |
checkset(os, cs) /* modify checked set and set to check */ |
654 |
< |
register OBJECT *os; /* os' = os - cs */ |
655 |
< |
register OBJECT *cs; /* cs' = cs + os */ |
653 |
> |
checkset( /* modify checked set and set to check */ |
654 |
> |
register OBJECT *os, /* os' = os - cs */ |
655 |
> |
register OBJECT *cs /* cs' = cs + os */ |
656 |
> |
) |
657 |
|
{ |
658 |
|
OBJECT cset[MAXCSET+MAXSET+1]; |
659 |
|
register int i, j; |