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#ifndef lint |
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static const char RCSid[] = "$Id$"; |
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#endif |
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/* |
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* o_instance.c - routines for computing ray intersections with octrees. |
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*/ |
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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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|
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#include "instance.h" |
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|
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|
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o_instance(o, r) /* compute ray intersection with octree */ |
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OBJREC *o; |
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register RAY *r; |
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{ |
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RAY rcont; |
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double d; |
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register INSTANCE *ins; |
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register int i; |
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/* get the octree */ |
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ins = getinstance(o, IO_ALL); |
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/* copy and transform ray */ |
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copystruct(&rcont, r); |
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multp3(rcont.rorg, r->rorg, ins->x.b.xfm); |
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multv3(rcont.rdir, r->rdir, ins->x.b.xfm); |
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for (i = 0; i < 3; i++) |
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rcont.rdir[i] /= ins->x.b.sca; |
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rcont.rmax *= ins->x.b.sca; |
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/* clear and trace it */ |
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rayclear(&rcont); |
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if (!localhit(&rcont, &ins->obj->scube)) |
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return(0); /* missed */ |
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if (rcont.rot * ins->x.f.sca >= r->rot) |
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return(0); /* not close enough */ |
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|
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if (o->omod != OVOID) { /* if we have modifier, use it */ |
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r->ro = o; |
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r->rox = NULL; |
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} else { /* else use theirs */ |
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r->ro = rcont.ro; |
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if (rcont.rox != NULL) { |
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newrayxf(r); /* allocate transformation */ |
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/* NOTE: r->rox may equal rcont.rox! */ |
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multmat4(r->rox->f.xfm, rcont.rox->f.xfm, ins->x.f.xfm); |
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r->rox->f.sca = rcont.rox->f.sca * ins->x.f.sca; |
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multmat4(r->rox->b.xfm, ins->x.b.xfm, rcont.rox->b.xfm); |
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r->rox->b.sca = ins->x.b.sca * rcont.rox->b.sca; |
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} else |
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r->rox = &ins->x; |
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} |
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/* transform it back */ |
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r->rot = rcont.rot * ins->x.f.sca; |
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multp3(r->rop, rcont.rop, ins->x.f.xfm); |
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multv3(r->ron, rcont.ron, ins->x.f.xfm); |
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multv3(r->pert, rcont.pert, ins->x.f.xfm); |
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d = 1./ins->x.f.sca; |
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for (i = 0; i < 3; i++) { |
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r->ron[i] *= d; |
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r->pert[i] *= d; |
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} |
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r->rod = rcont.rod; |
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r->uv[0] = rcont.uv[0]; |
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r->uv[1] = rcont.uv[1]; |
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/* return hit */ |
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return(1); |
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} |
