| 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 |
} |
