/* Copyright (c) 1987 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "@(#)bbox.c 2.1 11/12/91 LBL";
#endif

/*
 *  bbox.c - routines for bounding box computation.
 *
 *	8/4/87
 */

#include  "standard.h"

#include  "object.h"

#include  "otypes.h"

#include  "face.h"

#include  "cone.h"

#include  "instance.h"


add2bbox(o, bbmin, bbmax)		/* expand bounding box to fit object */
register OBJREC  *o;
FVECT  bbmin, bbmax;
{
	CONE  *co;
	FACE  *fo;
	INSTANCE  *io;
	FVECT  v;
	register int  i, j;

	switch (o->otype) {
	case OBJ_SPHERE:
	case OBJ_BUBBLE:
		if (o->oargs.nfargs != 4)
			objerror(o, USER, "bad arguments");
		for (i = 0; i < 3; i++) {
			VCOPY(v, o->oargs.farg);
			v[i] -= o->oargs.farg[3];
			point2bbox(v, bbmin, bbmax);
			v[i] += 2.0 * o->oargs.farg[3];
			point2bbox(v, bbmin, bbmax);
		}
		break;
	case OBJ_FACE:
		fo = getface(o);
		j = fo->nv;
		while (j--)
			point2bbox(VERTEX(fo,j), bbmin, bbmax);
		break;
	case OBJ_CONE:
	case OBJ_CUP:
	case OBJ_CYLINDER:
	case OBJ_TUBE:
	case OBJ_RING:
		co = getcone(o, 0);
		if (o->otype != OBJ_RING)
			circle2bbox(CO_P0(co), co->ad, CO_R0(co), bbmin, bbmax);
		circle2bbox(CO_P1(co), co->ad, CO_R1(co), bbmin, bbmax);
		break;
	case OBJ_INSTANCE:
		io = getinstance(o, IO_BOUNDS);
		for (j = 0; j < 8; j++) {
			for (i = 0; i < 3; i++) {
				v[i] = io->obj->scube.cuorg[i];
				if (j & 1<<i)
					v[i] += io->obj->scube.cusize;
			}
			multp3(v, v, io->x.f.xfm);
			point2bbox(v, bbmin, bbmax);
		}
		break;
	}
}


point2bbox(p, bbmin, bbmax)		/* expand bounding box to fit point */
register FVECT  p, bbmin, bbmax;
{
	register int  i;

	for (i = 0; i < 3; i++) {
		if (p[i] < bbmin[i])
			bbmin[i] = p[i];
		if (p[i] > bbmax[i])
			bbmax[i] = p[i];
	}
}


circle2bbox(cent, norm, rad, bbmin, bbmax)	/* expand bbox to fit circle */
FVECT  cent, norm;
double  rad;
FVECT  bbmin, bbmax;
{
	FVECT  v1, v2;
	register int  i, j;

	for (i = 0; i < 3; i++) {
		v1[0] = v1[1] = v1[2] = 0;
		v1[i] = 1.0;
		fcross(v2, norm, v1);
		if (normalize(v2) == 0.0)
			continue;
		for (j = 0; j < 3; j++)
			v1[j] = cent[j] + rad*v2[j];
		point2bbox(v1, bbmin, bbmax);
		for (j = 0; j < 3; j++)
			v1[j] = cent[j] - rad*v2[j];
		point2bbox(v1, bbmin, bbmax);
	}
}