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#ifndef lint |
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static const char RCSid[] = "$Id: raytrace.c,v 2.49 2005/04/19 01:15:06 greg Exp $"; |
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#endif |
4 |
/* |
5 |
* raytrace.c - routines for tracing and shading rays. |
6 |
* |
7 |
* External symbols declared in ray.h |
8 |
*/ |
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|
10 |
#include "copyright.h" |
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|
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#include "ray.h" |
13 |
#include "source.h" |
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#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 = { |
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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 |
RAY *r, |
40 |
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.); |
50 |
} 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->crtype = r->rtype = rt; |
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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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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->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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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 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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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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return(r->rlvl <= maxdepth && r->rweight >= minweight ? 0 : -1); |
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} |
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|
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|
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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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|
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|
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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 (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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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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|
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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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raytrans(r); |
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} |
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|
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|
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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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|
160 |
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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r->rt = r->rot + tr.rt; |
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} |
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} |
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|
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|
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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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register OBJREC *m; |
176 |
|
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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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m = objptr(mod); |
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/****** unnecessary test since modifier() is always called |
181 |
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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******/ |
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/* hack for irradiance calculation */ |
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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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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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if ((*ofun[m->otype].funp)(m, r)) |
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return(1); /* materials call raytexture() */ |
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} |
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return(0); /* no material! */ |
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} |
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|
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|
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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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|
212 |
if (intens(r->cext) <= 1./FHUGE) |
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return; /* no medium */ |
214 |
re = r->rot*colval(r->cext,RED); |
215 |
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 */ |
218 |
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<=FTINY ? 1. : re>92. ? 0. : exp(-re), |
223 |
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 */ |
226 |
if (r->crtype & SHADOW || intens(r->albedo) <= FTINY) |
227 |
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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} |
235 |
|
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|
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extern void |
238 |
raytexture( /* get material modifiers */ |
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RAY *r, |
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OBJECT mod |
241 |
) |
242 |
{ |
243 |
register OBJREC *m; |
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/* execute textures and patterns */ |
245 |
for ( ; mod != OVOID; mod = m->omod) { |
246 |
m = objptr(mod); |
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/****** unnecessary test since modifier() is always called |
248 |
if (!ismodifier(m->otype)) { |
249 |
sprintf(errmsg, "illegal modifier \"%s\"", m->oname); |
250 |
error(USER, errmsg); |
251 |
} |
252 |
******/ |
253 |
if ((*ofun[m->otype].funp)(m, r)) { |
254 |
sprintf(errmsg, "conflicting material \"%s\"", |
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m->oname); |
256 |
objerror(r->ro, USER, errmsg); |
257 |
} |
258 |
} |
259 |
} |
260 |
|
261 |
|
262 |
extern int |
263 |
raymixture( /* mix modifiers */ |
264 |
register RAY *r, |
265 |
OBJECT fore, |
266 |
OBJECT back, |
267 |
double coef |
268 |
) |
269 |
{ |
270 |
RAY fr, br; |
271 |
int foremat, backmat; |
272 |
register int i; |
273 |
/* bound coefficient */ |
274 |
if (coef > 1.0) |
275 |
coef = 1.0; |
276 |
else if (coef < 0.0) |
277 |
coef = 0.0; |
278 |
/* compute foreground and background */ |
279 |
foremat = backmat = 0; |
280 |
/* foreground */ |
281 |
fr = *r; |
282 |
if (coef > FTINY) |
283 |
foremat = rayshade(&fr, fore); |
284 |
/* background */ |
285 |
br = *r; |
286 |
if (coef < 1.0-FTINY) |
287 |
backmat = rayshade(&br, back); |
288 |
/* check for transparency */ |
289 |
if (backmat ^ foremat) { |
290 |
if (backmat && coef > FTINY) |
291 |
raytrans(&fr); |
292 |
else if (foremat && coef < 1.0-FTINY) |
293 |
raytrans(&br); |
294 |
} |
295 |
/* mix perturbations */ |
296 |
for (i = 0; i < 3; i++) |
297 |
r->pert[i] = coef*fr.pert[i] + (1.0-coef)*br.pert[i]; |
298 |
/* mix pattern colors */ |
299 |
scalecolor(fr.pcol, coef); |
300 |
scalecolor(br.pcol, 1.0-coef); |
301 |
copycolor(r->pcol, fr.pcol); |
302 |
addcolor(r->pcol, br.pcol); |
303 |
/* return value tells if material */ |
304 |
if (!foremat & !backmat) |
305 |
return(0); |
306 |
/* mix returned ray values */ |
307 |
scalecolor(fr.rcol, coef); |
308 |
scalecolor(br.rcol, 1.0-coef); |
309 |
copycolor(r->rcol, fr.rcol); |
310 |
addcolor(r->rcol, br.rcol); |
311 |
r->rt = bright(fr.rcol) > bright(br.rcol) ? fr.rt : br.rt; |
312 |
return(1); |
313 |
} |
314 |
|
315 |
|
316 |
extern double |
317 |
raydist( /* compute (cumulative) ray distance */ |
318 |
register const RAY *r, |
319 |
register int flags |
320 |
) |
321 |
{ |
322 |
double sum = 0.0; |
323 |
|
324 |
while (r != NULL && r->crtype&flags) { |
325 |
sum += r->rot; |
326 |
r = r->parent; |
327 |
} |
328 |
return(sum); |
329 |
} |
330 |
|
331 |
|
332 |
extern void |
333 |
raycontrib( /* compute (cumulative) ray contribution */ |
334 |
COLOR rc, |
335 |
const RAY *r, |
336 |
int flags |
337 |
) |
338 |
{ |
339 |
COLOR eext, ext1; |
340 |
|
341 |
setcolor(eext, 0., 0., 0.); |
342 |
setcolor(rc, 1., 1., 1.); |
343 |
|
344 |
while (r != NULL && r->crtype&flags) { |
345 |
multcolor(rc, r->rcoef); |
346 |
copycolor(ext1, r->cext); |
347 |
scalecolor(ext1, r->rot); |
348 |
addcolor(eext, ext1); |
349 |
r = r->parent; |
350 |
} |
351 |
if (intens(eext) > FTINY) { |
352 |
setcolor(ext1, exp(-colval(eext,RED)), |
353 |
exp(-colval(eext,GRN)), |
354 |
exp(-colval(eext,BLU))); |
355 |
multcolor(rc, ext1); |
356 |
} |
357 |
} |
358 |
|
359 |
|
360 |
extern double |
361 |
raynormal( /* compute perturbed normal for ray */ |
362 |
FVECT norm, |
363 |
register RAY *r |
364 |
) |
365 |
{ |
366 |
double newdot; |
367 |
register int i; |
368 |
|
369 |
/* The perturbation is added to the surface normal to obtain |
370 |
* the new normal. If the new normal would affect the surface |
371 |
* orientation wrt. the ray, a correction is made. The method is |
372 |
* still fraught with problems since reflected rays and similar |
373 |
* directions calculated from the surface normal may spawn rays behind |
374 |
* the surface. The only solution is to curb textures at high |
375 |
* incidence (namely, keep DOT(rdir,pert) < Rdot). |
376 |
*/ |
377 |
|
378 |
for (i = 0; i < 3; i++) |
379 |
norm[i] = r->ron[i] + r->pert[i]; |
380 |
|
381 |
if (normalize(norm) == 0.0) { |
382 |
objerror(r->ro, WARNING, "illegal normal perturbation"); |
383 |
VCOPY(norm, r->ron); |
384 |
return(r->rod); |
385 |
} |
386 |
newdot = -DOT(norm, r->rdir); |
387 |
if ((newdot > 0.0) != (r->rod > 0.0)) { /* fix orientation */ |
388 |
for (i = 0; i < 3; i++) |
389 |
norm[i] += 2.0*newdot*r->rdir[i]; |
390 |
newdot = -newdot; |
391 |
} |
392 |
return(newdot); |
393 |
} |
394 |
|
395 |
|
396 |
extern void |
397 |
newrayxf( /* get new tranformation matrix for ray */ |
398 |
RAY *r |
399 |
) |
400 |
{ |
401 |
static struct xfn { |
402 |
struct xfn *next; |
403 |
FULLXF xf; |
404 |
} xfseed = { &xfseed }, *xflast = &xfseed; |
405 |
register struct xfn *xp; |
406 |
register const RAY *rp; |
407 |
|
408 |
/* |
409 |
* Search for transform in circular list that |
410 |
* has no associated ray in the tree. |
411 |
*/ |
412 |
xp = xflast; |
413 |
for (rp = r->parent; rp != NULL; rp = rp->parent) |
414 |
if (rp->rox == &xp->xf) { /* xp in use */ |
415 |
xp = xp->next; /* move to next */ |
416 |
if (xp == xflast) { /* need new one */ |
417 |
xp = (struct xfn *)malloc(sizeof(struct xfn)); |
418 |
if (xp == NULL) |
419 |
error(SYSTEM, |
420 |
"out of memory in newrayxf"); |
421 |
/* insert in list */ |
422 |
xp->next = xflast->next; |
423 |
xflast->next = xp; |
424 |
break; /* we're done */ |
425 |
} |
426 |
rp = r; /* start check over */ |
427 |
} |
428 |
/* got it */ |
429 |
r->rox = &xp->xf; |
430 |
xflast = xp; |
431 |
} |
432 |
|
433 |
|
434 |
extern void |
435 |
flipsurface( /* reverse surface orientation */ |
436 |
register RAY *r |
437 |
) |
438 |
{ |
439 |
r->rod = -r->rod; |
440 |
r->ron[0] = -r->ron[0]; |
441 |
r->ron[1] = -r->ron[1]; |
442 |
r->ron[2] = -r->ron[2]; |
443 |
r->pert[0] = -r->pert[0]; |
444 |
r->pert[1] = -r->pert[1]; |
445 |
r->pert[2] = -r->pert[2]; |
446 |
} |
447 |
|
448 |
|
449 |
extern void |
450 |
rayhit( /* standard ray hit test */ |
451 |
OBJECT *oset, |
452 |
RAY *r |
453 |
) |
454 |
{ |
455 |
OBJREC *o; |
456 |
int i; |
457 |
|
458 |
for (i = oset[0]; i > 0; i--) { |
459 |
o = objptr(oset[i]); |
460 |
if ((*ofun[o->otype].funp)(o, r)) |
461 |
r->robj = oset[i]; |
462 |
} |
463 |
} |
464 |
|
465 |
|
466 |
extern int |
467 |
localhit( /* check for hit in the octree */ |
468 |
register RAY *r, |
469 |
register CUBE *scene |
470 |
) |
471 |
{ |
472 |
OBJECT cxset[MAXCSET+1]; /* set of checked objects */ |
473 |
FVECT curpos; /* current cube position */ |
474 |
int sflags; /* sign flags */ |
475 |
double t, dt; |
476 |
register int i; |
477 |
|
478 |
nrays++; /* increment trace counter */ |
479 |
sflags = 0; |
480 |
for (i = 0; i < 3; i++) { |
481 |
curpos[i] = r->rorg[i]; |
482 |
if (r->rdir[i] > 1e-7) |
483 |
sflags |= 1 << i; |
484 |
else if (r->rdir[i] < -1e-7) |
485 |
sflags |= 0x10 << i; |
486 |
} |
487 |
if (sflags == 0) |
488 |
error(CONSISTENCY, "zero ray direction in localhit"); |
489 |
/* start off assuming nothing hit */ |
490 |
if (r->rmax > FTINY) { /* except aft plane if one */ |
491 |
r->ro = &Aftplane; |
492 |
r->rot = r->rmax; |
493 |
for (i = 0; i < 3; i++) |
494 |
r->rop[i] = r->rorg[i] + r->rot*r->rdir[i]; |
495 |
} |
496 |
/* find global cube entrance point */ |
497 |
t = 0.0; |
498 |
if (!incube(scene, curpos)) { |
499 |
/* find distance to entry */ |
500 |
for (i = 0; i < 3; i++) { |
501 |
/* plane in our direction */ |
502 |
if (sflags & 1<<i) |
503 |
dt = scene->cuorg[i]; |
504 |
else if (sflags & 0x10<<i) |
505 |
dt = scene->cuorg[i] + scene->cusize; |
506 |
else |
507 |
continue; |
508 |
/* distance to the plane */ |
509 |
dt = (dt - r->rorg[i])/r->rdir[i]; |
510 |
if (dt > t) |
511 |
t = dt; /* farthest face is the one */ |
512 |
} |
513 |
t += FTINY; /* fudge to get inside cube */ |
514 |
if (t >= r->rot) /* clipped already */ |
515 |
return(0); |
516 |
/* advance position */ |
517 |
for (i = 0; i < 3; i++) |
518 |
curpos[i] += r->rdir[i]*t; |
519 |
|
520 |
if (!incube(scene, curpos)) /* non-intersecting ray */ |
521 |
return(0); |
522 |
} |
523 |
cxset[0] = 0; |
524 |
raymove(curpos, cxset, sflags, r, scene); |
525 |
return((r->ro != NULL) & (r->ro != &Aftplane)); |
526 |
} |
527 |
|
528 |
|
529 |
static int |
530 |
raymove( /* check for hit as we move */ |
531 |
FVECT pos, /* current position, modified herein */ |
532 |
OBJECT *cxs, /* checked objects, modified by checkhit */ |
533 |
int dirf, /* direction indicators to speed tests */ |
534 |
register RAY *r, |
535 |
register CUBE *cu |
536 |
) |
537 |
{ |
538 |
int ax; |
539 |
double dt, t; |
540 |
|
541 |
if (istree(cu->cutree)) { /* recurse on subcubes */ |
542 |
CUBE cukid; |
543 |
register int br, sgn; |
544 |
|
545 |
cukid.cusize = cu->cusize * 0.5; /* find subcube */ |
546 |
VCOPY(cukid.cuorg, cu->cuorg); |
547 |
br = 0; |
548 |
if (pos[0] >= cukid.cuorg[0]+cukid.cusize) { |
549 |
cukid.cuorg[0] += cukid.cusize; |
550 |
br |= 1; |
551 |
} |
552 |
if (pos[1] >= cukid.cuorg[1]+cukid.cusize) { |
553 |
cukid.cuorg[1] += cukid.cusize; |
554 |
br |= 2; |
555 |
} |
556 |
if (pos[2] >= cukid.cuorg[2]+cukid.cusize) { |
557 |
cukid.cuorg[2] += cukid.cusize; |
558 |
br |= 4; |
559 |
} |
560 |
for ( ; ; ) { |
561 |
cukid.cutree = octkid(cu->cutree, br); |
562 |
if ((ax = raymove(pos,cxs,dirf,r,&cukid)) == RAYHIT) |
563 |
return(RAYHIT); |
564 |
sgn = 1 << ax; |
565 |
if (sgn & dirf) /* positive axis? */ |
566 |
if (sgn & br) |
567 |
return(ax); /* overflow */ |
568 |
else { |
569 |
cukid.cuorg[ax] += cukid.cusize; |
570 |
br |= sgn; |
571 |
} |
572 |
else |
573 |
if (sgn & br) { |
574 |
cukid.cuorg[ax] -= cukid.cusize; |
575 |
br &= ~sgn; |
576 |
} else |
577 |
return(ax); /* underflow */ |
578 |
} |
579 |
/*NOTREACHED*/ |
580 |
} |
581 |
if (isfull(cu->cutree)) { |
582 |
if (checkhit(r, cu, cxs)) |
583 |
return(RAYHIT); |
584 |
} else if (r->ro == &Aftplane && incube(cu, r->rop)) |
585 |
return(RAYHIT); |
586 |
/* advance to next cube */ |
587 |
if (dirf&0x11) { |
588 |
dt = dirf&1 ? cu->cuorg[0] + cu->cusize : cu->cuorg[0]; |
589 |
t = (dt - pos[0])/r->rdir[0]; |
590 |
ax = 0; |
591 |
} else |
592 |
t = FHUGE; |
593 |
if (dirf&0x22) { |
594 |
dt = dirf&2 ? cu->cuorg[1] + cu->cusize : cu->cuorg[1]; |
595 |
dt = (dt - pos[1])/r->rdir[1]; |
596 |
if (dt < t) { |
597 |
t = dt; |
598 |
ax = 1; |
599 |
} |
600 |
} |
601 |
if (dirf&0x44) { |
602 |
dt = dirf&4 ? cu->cuorg[2] + cu->cusize : cu->cuorg[2]; |
603 |
dt = (dt - pos[2])/r->rdir[2]; |
604 |
if (dt < t) { |
605 |
t = dt; |
606 |
ax = 2; |
607 |
} |
608 |
} |
609 |
pos[0] += r->rdir[0]*t; |
610 |
pos[1] += r->rdir[1]*t; |
611 |
pos[2] += r->rdir[2]*t; |
612 |
return(ax); |
613 |
} |
614 |
|
615 |
|
616 |
static int |
617 |
checkhit( /* check for hit in full cube */ |
618 |
register RAY *r, |
619 |
CUBE *cu, |
620 |
OBJECT *cxs |
621 |
) |
622 |
{ |
623 |
OBJECT oset[MAXSET+1]; |
624 |
|
625 |
objset(oset, cu->cutree); |
626 |
checkset(oset, cxs); /* avoid double-checking */ |
627 |
|
628 |
(*r->hitf)(oset, r); /* test for hit in set */ |
629 |
|
630 |
if (r->robj == OVOID) |
631 |
return(0); /* no scores yet */ |
632 |
|
633 |
return(incube(cu, r->rop)); /* hit OK if in current cube */ |
634 |
} |
635 |
|
636 |
|
637 |
static void |
638 |
checkset( /* modify checked set and set to check */ |
639 |
register OBJECT *os, /* os' = os - cs */ |
640 |
register OBJECT *cs /* cs' = cs + os */ |
641 |
) |
642 |
{ |
643 |
OBJECT cset[MAXCSET+MAXSET+1]; |
644 |
register int i, j; |
645 |
int k; |
646 |
/* copy os in place, cset <- cs */ |
647 |
cset[0] = 0; |
648 |
k = 0; |
649 |
for (i = j = 1; i <= os[0]; i++) { |
650 |
while (j <= cs[0] && cs[j] < os[i]) |
651 |
cset[++cset[0]] = cs[j++]; |
652 |
if (j > cs[0] || os[i] != cs[j]) { /* object to check */ |
653 |
os[++k] = os[i]; |
654 |
cset[++cset[0]] = os[i]; |
655 |
} |
656 |
} |
657 |
if (!(os[0] = k)) /* new "to check" set size */ |
658 |
return; /* special case */ |
659 |
while (j <= cs[0]) /* get the rest of cs */ |
660 |
cset[++cset[0]] = cs[j++]; |
661 |
if (cset[0] > MAXCSET) /* truncate "checked" set if nec. */ |
662 |
cset[0] = MAXCSET; |
663 |
/* setcopy(cs, cset); */ /* copy cset back to cs */ |
664 |
os = cset; |
665 |
for (i = os[0]; i-- >= 0; ) |
666 |
*cs++ = *os++; |
667 |
} |