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/* Copyright (c) 1991 Regents of the University of California */ |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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static const char RCSid[] = "$Id$"; |
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#endif |
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|
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/* |
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* raytrace.c - routines for tracing and shading rays. |
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* |
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* 8/7/85 |
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* External symbols declared in ray.h |
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*/ |
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#include "copyright.h" |
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|
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#include "ray.h" |
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#include "octree.h" |
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|
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#include "otypes.h" |
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#include "otspecial.h" |
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#define MAXCSET ((MAXSET+1)*2-1) /* maximum check set size */ |
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|
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extern CUBE thescene; /* our scene */ |
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extern int maxdepth; /* maximum recursion depth */ |
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extern double minweight; /* minimum ray weight */ |
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extern int do_irrad; /* compute irradiance? */ |
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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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{0, 5, NULL, Lambfa}, NULL, |
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}; /* a Lambertian surface */ |
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static int raymove(), checkset(), checkhit(); |
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OBJREC Aftplane; /* aft clipping plane object */ |
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#define MAXLOOP 128 /* modifier loop detection */ |
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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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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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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->rsrc = -1; |
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r->clipset = NULL; |
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r->revf = raytrace; |
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copycolor(r->cext, cextinction); |
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copycolor(r->albedo, salbedo); |
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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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r->rlvl = ro->rlvl; |
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if (rt & RAYREFL) { |
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r->rlvl++; |
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r->rsrc = -1; |
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r->clipset = ro->clipset; |
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r->rmax = 0.0; |
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} else { |
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r->rsrc = ro->rsrc; |
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r->clipset = ro->newcset; |
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r->rmax = ro->rmax <= FTINY ? 0.0 : ro->rmax - ro->rot; |
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} |
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r->revf = ro->revf; |
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r->rweight = ro->rweight * rw; |
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copycolor(r->cext, ro->cext); |
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copycolor(r->albedo, ro->albedo); |
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r->gecc = ro->gecc; |
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r->slights = ro->slights; |
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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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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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} |
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rayclear(r); |
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return(r->rlvl <= maxdepth && r->rweight >= minweight ? 0 : -1); |
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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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{ |
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r->rno = raynum++; |
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r->newcset = r->clipset; |
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r->robj = OVOID; |
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r->ro = NULL; |
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r->rot = FHUGE; |
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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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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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r->rt = 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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{ |
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extern int (*trace)(); |
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|
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if (localhit(r, &thescene)) |
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raycont(r); |
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else if (sourcehit(r)) |
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rayshade(r, r->ro->omod); |
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raycont(r); /* hit local surface, evaluate */ |
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else if (r->ro == &Aftplane) { |
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r->ro = NULL; /* hit aft clipping plane */ |
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r->rot = FHUGE; |
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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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void |
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raycont(r) /* check for clipped object and continue */ |
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register RAY *r; |
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{ |
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if ((r->clipset != NULL && inset(r->clipset, r->ro->omod)) || |
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r->ro->omod == OVOID) |
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!rayshade(r, r->ro->omod)) |
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raytrans(r); |
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else |
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rayshade(r, r->ro->omod); |
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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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{ |
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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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{ |
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static int depth = 0; |
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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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r->rt = r->rot; /* set effective ray length */ |
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for ( ; mod != OVOID; mod = m->omod) { |
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for (gotmat = 0; !gotmat && 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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/* hack for irradiance calculation */ |
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if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS))) { |
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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; |
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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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(*ofun[m->otype].funp)(m, r); /* execute function */ |
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if (ismaterial(m->otype)) { /* materials call raytexture */ |
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depth--; |
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return; /* we're done */ |
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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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} |
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objerror(r->ro, USER, "material not found"); |
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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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} |
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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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{ |
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COLOR ce, ca; |
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double re, ge, be; |
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|
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if (intens(r->cext) <= 1./FHUGE) |
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return; /* no medium */ |
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re = r->rot*colval(r->cext,RED); |
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ge = r->rot*colval(r->cext,GRN); |
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be = r->rot*colval(r->cext,BLU); |
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if (r->crtype & SHADOW) { /* no scattering for sources */ |
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re *= 1. - colval(r->albedo,RED); |
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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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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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colval(r->albedo,RED)*colval(ambval,RED)*(1.-colval(ce,RED)), |
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colval(r->albedo,GRN)*colval(ambval,GRN)*(1.-colval(ce,GRN)), |
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colval(r->albedo,BLU)*colval(ambval,BLU)*(1.-colval(ce,BLU))); |
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addcolor(r->rcol, ca); /* ambient in scattering */ |
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srcscatter(r); /* source in scattering */ |
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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; |
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int mod; |
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{ |
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static int depth = 0; |
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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, "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) { |
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m = objptr(mod); |
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if (!istexture(m->otype)) { |
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/****** unnecessary test since modifier() is always called |
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if (!ismodifier(m->otype)) { |
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sprintf(errmsg, "illegal modifier \"%s\"", m->oname); |
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error(USER, errmsg); |
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} |
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(*ofun[m->otype].funp)(m, r); |
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******/ |
248 |
> |
if ((*ofun[m->otype].funp)(m, r)) { |
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sprintf(errmsg, "conflicting material \"%s\"", |
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m->oname); |
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objerror(r->ro, USER, errmsg); |
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} |
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} |
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#if MAXLOOP |
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depth--; /* end here */ |
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#endif |
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} |
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|
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|
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int |
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raymixture(r, fore, back, coef) /* mix modifiers */ |
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register RAY *r; |
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OBJECT fore, back; |
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double coef; |
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{ |
266 |
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FVECT curpert, forepert, backpert; |
267 |
< |
COLOR curpcol, forepcol, backpcol; |
266 |
> |
RAY fr, br; |
267 |
> |
int foremat, backmat; |
268 |
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register int i; |
269 |
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/* clip coefficient */ |
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> |
/* bound coefficient */ |
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if (coef > 1.0) |
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coef = 1.0; |
272 |
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else if (coef < 0.0) |
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coef = 0.0; |
274 |
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/* save current mods */ |
275 |
< |
VCOPY(curpert, r->pert); |
276 |
< |
copycolor(curpcol, r->pcol); |
277 |
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/* compute new mods */ |
278 |
< |
/* foreground */ |
279 |
< |
r->pert[0] = r->pert[1] = r->pert[2] = 0.0; |
280 |
< |
setcolor(r->pcol, 1.0, 1.0, 1.0); |
281 |
< |
if (fore != OVOID && coef > FTINY) |
282 |
< |
raytexture(r, fore); |
283 |
< |
VCOPY(forepert, r->pert); |
284 |
< |
copycolor(forepcol, r->pcol); |
285 |
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/* background */ |
286 |
< |
r->pert[0] = r->pert[1] = r->pert[2] = 0.0; |
287 |
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setcolor(r->pcol, 1.0, 1.0, 1.0); |
288 |
< |
if (back != OVOID && coef < 1.0-FTINY) |
289 |
< |
raytexture(r, back); |
290 |
< |
VCOPY(backpert, r->pert); |
220 |
< |
copycolor(backpcol, r->pcol); |
221 |
< |
/* sum perturbations */ |
274 |
> |
/* compute foreground and background */ |
275 |
> |
foremat = backmat = 0; |
276 |
> |
/* foreground */ |
277 |
> |
copystruct(&fr, r); |
278 |
> |
if (coef > FTINY) |
279 |
> |
foremat = rayshade(&fr, fore); |
280 |
> |
/* background */ |
281 |
> |
copystruct(&br, r); |
282 |
> |
if (coef < 1.0-FTINY) |
283 |
> |
backmat = rayshade(&br, back); |
284 |
> |
/* check for transparency */ |
285 |
> |
if (backmat ^ foremat) |
286 |
> |
if (backmat && coef > FTINY) |
287 |
> |
raytrans(&fr); |
288 |
> |
else if (foremat && coef < 1.0-FTINY) |
289 |
> |
raytrans(&br); |
290 |
> |
/* mix perturbations */ |
291 |
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for (i = 0; i < 3; i++) |
292 |
< |
r->pert[i] = curpert[i] + coef*forepert[i] + |
293 |
< |
(1.0-coef)*backpert[i]; |
294 |
< |
/* multiply colors */ |
295 |
< |
setcolor(r->pcol, coef*colval(forepcol,RED) + |
296 |
< |
(1.0-coef)*colval(backpcol,RED), |
297 |
< |
coef*colval(forepcol,GRN) + |
298 |
< |
(1.0-coef)*colval(backpcol,GRN), |
299 |
< |
coef*colval(forepcol,BLU) + |
300 |
< |
(1.0-coef)*colval(backpcol,BLU)); |
301 |
< |
multcolor(r->pcol, curpcol); |
292 |
> |
r->pert[i] = coef*fr.pert[i] + (1.0-coef)*br.pert[i]; |
293 |
> |
/* mix pattern colors */ |
294 |
> |
scalecolor(fr.pcol, coef); |
295 |
> |
scalecolor(br.pcol, 1.0-coef); |
296 |
> |
copycolor(r->pcol, fr.pcol); |
297 |
> |
addcolor(r->pcol, br.pcol); |
298 |
> |
/* return value tells if material */ |
299 |
> |
if (!foremat & !backmat) |
300 |
> |
return(0); |
301 |
> |
/* mix returned ray values */ |
302 |
> |
scalecolor(fr.rcol, coef); |
303 |
> |
scalecolor(br.rcol, 1.0-coef); |
304 |
> |
copycolor(r->rcol, fr.rcol); |
305 |
> |
addcolor(r->rcol, br.rcol); |
306 |
> |
r->rt = bright(fr.rcol) > bright(br.rcol) ? fr.rt : br.rt; |
307 |
> |
return(1); |
308 |
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} |
309 |
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|
310 |
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|
311 |
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double |
312 |
+ |
raydist(r, flags) /* compute (cumulative) ray distance */ |
313 |
+ |
register RAY *r; |
314 |
+ |
register int flags; |
315 |
+ |
{ |
316 |
+ |
double sum = 0.0; |
317 |
+ |
|
318 |
+ |
while (r != NULL && r->crtype&flags) { |
319 |
+ |
sum += r->rot; |
320 |
+ |
r = r->parent; |
321 |
+ |
} |
322 |
+ |
return(sum); |
323 |
+ |
} |
324 |
+ |
|
325 |
+ |
|
326 |
+ |
double |
327 |
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raynormal(norm, r) /* compute perturbed normal for ray */ |
328 |
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FVECT norm; |
329 |
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register RAY *r; |
358 |
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} |
359 |
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|
360 |
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|
361 |
+ |
void |
362 |
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newrayxf(r) /* get new tranformation matrix for ray */ |
363 |
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RAY *r; |
364 |
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{ |
378 |
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if (rp->rox == &xp->xf) { /* xp in use */ |
379 |
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xp = xp->next; /* move to next */ |
380 |
|
if (xp == xflast) { /* need new one */ |
381 |
< |
xp = (struct xfn *)bmalloc(sizeof(struct xfn)); |
381 |
> |
xp = (struct xfn *)malloc(sizeof(struct xfn)); |
382 |
|
if (xp == NULL) |
383 |
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error(SYSTEM, |
384 |
|
"out of memory in newrayxf"); |
395 |
|
} |
396 |
|
|
397 |
|
|
398 |
+ |
void |
399 |
|
flipsurface(r) /* reverse surface orientation */ |
400 |
|
register RAY *r; |
401 |
|
{ |
409 |
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} |
410 |
|
|
411 |
|
|
412 |
+ |
int |
413 |
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localhit(r, scene) /* check for hit in the octree */ |
414 |
|
register RAY *r; |
415 |
|
register CUBE *scene; |
431 |
|
} |
432 |
|
if (sflags == 0) |
433 |
|
error(CONSISTENCY, "zero ray direction in localhit"); |
434 |
+ |
/* start off assuming nothing hit */ |
435 |
+ |
if (r->rmax > FTINY) { /* except aft plane if one */ |
436 |
+ |
r->ro = &Aftplane; |
437 |
+ |
r->rot = r->rmax; |
438 |
+ |
for (i = 0; i < 3; i++) |
439 |
+ |
r->rop[i] = r->rorg[i] + r->rot*r->rdir[i]; |
440 |
+ |
} |
441 |
+ |
/* find global cube entrance point */ |
442 |
|
t = 0.0; |
443 |
|
if (!incube(scene, curpos)) { |
444 |
|
/* find distance to entry */ |
456 |
|
t = dt; /* farthest face is the one */ |
457 |
|
} |
458 |
|
t += FTINY; /* fudge to get inside cube */ |
459 |
+ |
if (t >= r->rot) /* clipped already */ |
460 |
+ |
return(0); |
461 |
|
/* advance position */ |
462 |
|
for (i = 0; i < 3; i++) |
463 |
|
curpos[i] += r->rdir[i]*t; |
466 |
|
return(0); |
467 |
|
} |
468 |
|
cxset[0] = 0; |
469 |
< |
return(raymove(curpos, cxset, sflags, r, scene) == RAYHIT); |
469 |
> |
raymove(curpos, cxset, sflags, r, scene); |
470 |
> |
return(r->ro != NULL & r->ro != &Aftplane); |
471 |
|
} |
472 |
|
|
473 |
|
|
522 |
|
} |
523 |
|
/*NOTREACHED*/ |
524 |
|
} |
525 |
< |
if (isfull(cu->cutree) && checkhit(r, cu, cxs)) |
525 |
> |
if (isfull(cu->cutree)) { |
526 |
> |
if (checkhit(r, cu, cxs)) |
527 |
> |
return(RAYHIT); |
528 |
> |
} else if (r->ro == &Aftplane && incube(cu, r->rop)) |
529 |
|
return(RAYHIT); |
530 |
|
/* advance to next cube */ |
531 |
|
if (dirf&0x11) { |
557 |
|
} |
558 |
|
|
559 |
|
|
560 |
< |
static |
560 |
> |
static int |
561 |
|
checkhit(r, cu, cxs) /* check for hit in full cube */ |
562 |
|
register RAY *r; |
563 |
|
CUBE *cu; |
571 |
|
checkset(oset, cxs); /* eliminate double-checking */ |
572 |
|
for (i = oset[0]; i > 0; i--) { |
573 |
|
o = objptr(oset[i]); |
574 |
< |
(*ofun[o->otype].funp)(o, r); |
574 |
> |
if ((*ofun[o->otype].funp)(o, r)) |
575 |
> |
r->robj = oset[i]; |
576 |
|
} |
577 |
|
if (r->ro == NULL) |
578 |
|
return(0); /* no scores yet */ |
581 |
|
} |
582 |
|
|
583 |
|
|
584 |
< |
static |
584 |
> |
static void |
585 |
|
checkset(os, cs) /* modify checked set and set to check */ |
586 |
|
register OBJECT *os; /* os' = os - cs */ |
587 |
|
register OBJECT *cs; /* cs' = cs + os */ |