1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: o_instance.c,v 2.6 2003/03/11 17:08:55 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* o_instance.c - routines for computing ray intersections with octrees. |
6 |
*/ |
7 |
|
8 |
#include "copyright.h" |
9 |
|
10 |
#include "ray.h" |
11 |
|
12 |
#include "instance.h" |
13 |
|
14 |
|
15 |
o_instance(o, r) /* compute ray intersection with octree */ |
16 |
OBJREC *o; |
17 |
register RAY *r; |
18 |
{ |
19 |
RAY rcont; |
20 |
double d; |
21 |
register INSTANCE *ins; |
22 |
register int i; |
23 |
/* get the octree */ |
24 |
ins = getinstance(o, IO_ALL); |
25 |
/* copy and transform ray */ |
26 |
rcont = *r; |
27 |
multp3(rcont.rorg, r->rorg, ins->x.b.xfm); |
28 |
multv3(rcont.rdir, r->rdir, ins->x.b.xfm); |
29 |
for (i = 0; i < 3; i++) |
30 |
rcont.rdir[i] /= ins->x.b.sca; |
31 |
rcont.rmax *= ins->x.b.sca; |
32 |
/* clear and trace it */ |
33 |
rayclear(&rcont); |
34 |
if (!localhit(&rcont, &ins->obj->scube)) |
35 |
return(0); /* missed */ |
36 |
if (rcont.rot * ins->x.f.sca >= r->rot) |
37 |
return(0); /* not close enough */ |
38 |
|
39 |
if (o->omod != OVOID) { /* if we have modifier, use it */ |
40 |
r->ro = o; |
41 |
r->rox = NULL; |
42 |
} else { /* else use theirs */ |
43 |
r->ro = rcont.ro; |
44 |
if (rcont.rox != NULL) { |
45 |
newrayxf(r); /* allocate transformation */ |
46 |
/* NOTE: r->rox may equal rcont.rox! */ |
47 |
multmat4(r->rox->f.xfm, rcont.rox->f.xfm, ins->x.f.xfm); |
48 |
r->rox->f.sca = rcont.rox->f.sca * ins->x.f.sca; |
49 |
multmat4(r->rox->b.xfm, ins->x.b.xfm, rcont.rox->b.xfm); |
50 |
r->rox->b.sca = ins->x.b.sca * rcont.rox->b.sca; |
51 |
} else |
52 |
r->rox = &ins->x; |
53 |
} |
54 |
/* transform it back */ |
55 |
r->rot = rcont.rot * ins->x.f.sca; |
56 |
multp3(r->rop, rcont.rop, ins->x.f.xfm); |
57 |
multv3(r->ron, rcont.ron, ins->x.f.xfm); |
58 |
multv3(r->pert, rcont.pert, ins->x.f.xfm); |
59 |
d = 1./ins->x.f.sca; |
60 |
for (i = 0; i < 3; i++) { |
61 |
r->ron[i] *= d; |
62 |
r->pert[i] *= d; |
63 |
} |
64 |
r->rod = rcont.rod; |
65 |
r->uv[0] = rcont.uv[0]; |
66 |
r->uv[1] = rcont.uv[1]; |
67 |
/* return hit */ |
68 |
return(1); |
69 |
} |