--- ray/src/rt/o_instance.c	1989/04/11 13:30:30	1.2
+++ ray/src/rt/o_instance.c	2003/02/22 02:07:29	2.4
@@ -1,13 +1,65 @@
-/* Copyright (c) 1988 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: o_instance.c,v 2.4 2003/02/22 02:07:29 greg Exp $";
 #endif
-
 /*
  *  o_instance.c - routines for computing ray intersections with octrees.
+ */
+
+/* ====================================================================
+ * The Radiance Software License, Version 1.0
  *
- *     11/11/88
+ * Copyright (c) 1990 - 2002 The Regents of the University of California,
+ * through Lawrence Berkeley National Laboratory.   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *         notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *           if any, must include the following acknowledgment:
+ *             "This product includes Radiance software
+ *                 (http://radsite.lbl.gov/)
+ *                 developed by the Lawrence Berkeley National Laboratory
+ *               (http://www.lbl.gov/)."
+ *       Alternately, this acknowledgment may appear in the software itself,
+ *       if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
+ *       and "The Regents of the University of California" must
+ *       not be used to endorse or promote products derived from this
+ *       software without prior written permission. For written
+ *       permission, please contact radiance@radsite.lbl.gov.
+ *
+ * 5. Products derived from this software may not be called "Radiance",
+ *       nor may "Radiance" appear in their name, without prior written
+ *       permission of Lawrence Berkeley National Laboratory.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of Lawrence Berkeley National Laboratory.   For more
+ * information on Lawrence Berkeley National Laboratory, please see
+ * <http://www.lbl.gov/>.
  */
 
 #include  "ray.h"
@@ -19,44 +71,46 @@ o_instance(o, r)		/* compute ray intersection with oct
 OBJREC  *o;
 register RAY  *r;
 {
-	extern long  nrays;
 	RAY  rcont;
 	register INSTANCE  *in;
 	register int  i;
 					/* get the octree */
-	in = getinstance(o, GET_ALL);
-					/* copy old ray */
-	bcopy(r, &rcont, sizeof(RAY));
-					/* transform it */
-	rcont.rno = nrays;
-	rcont.ro = NULL;
-	rcont.rot = FHUGE;
-	rcont.rno = nrays;
-	multp3(rcont.rorg, r->rorg, in->b.xfm);
-	multv3(rcont.rdir, r->rdir, in->b.xfm);
+	in = getinstance(o, IO_ALL);
+					/* copy and transform ray */
+	copystruct(&rcont, r);
+	multp3(rcont.rorg, r->rorg, in->x.b.xfm);
+	multv3(rcont.rdir, r->rdir, in->x.b.xfm);
 	for (i = 0; i < 3; i++)
-		rcont.rdir[i] /= in->b.sca;
-					/* trace it */
+		rcont.rdir[i] /= in->x.b.sca;
+	rcont.rmax *= in->x.b.sca;
+					/* clear and trace it */
+	rayclear(&rcont);
 	if (!localhit(&rcont, &in->obj->scube))
-		return(0);		/* missed */
-	if (rcont.rot * in->f.sca >= r->rot)
-		return(0);		/* not close enough */
-					/* if we have modifier, use it */
-	if (o->omod != OVOID)
+		return(0);			/* missed */
+	if (rcont.rot * in->x.f.sca >= r->rot)
+		return(0);			/* not close enough */
+
+	if (o->omod != OVOID) {		/* if we have modifier, use it */
 		r->ro = o;
-	else {				/* else use theirs */
+		r->rox = NULL;
+	} else {			/* else use theirs */
 		r->ro = rcont.ro;
-		multmat4(r->rofx, in->f.xfm, rcont.rofx);
-		r->rofs = in->f.sca * rcont.rofs;
-		multmat4(r->robx, in->b.xfm, rcont.robx);
-		r->robs = in->b.sca * rcont.robs;
+		if (rcont.rox != NULL) {
+			newrayxf(r);		/* allocate transformation */
+					/* NOTE: r->rox may equal rcont.rox! */
+			multmat4(r->rox->f.xfm, rcont.rox->f.xfm, in->x.f.xfm);
+			r->rox->f.sca = rcont.rox->f.sca * in->x.f.sca;
+			multmat4(r->rox->b.xfm, in->x.b.xfm, rcont.rox->b.xfm);
+			r->rox->b.sca = in->x.b.sca * rcont.rox->b.sca;
+		} else
+			r->rox = &in->x;
 	}
 					/* transform it back */
-	r->rot = rcont.rot * in->f.sca;
-	multp3(r->rop, rcont.rop, in->f.xfm);
-	multv3(r->ron, rcont.ron, in->f.xfm);
+	r->rot = rcont.rot * in->x.f.sca;
+	multp3(r->rop, rcont.rop, in->x.f.xfm);
+	multv3(r->ron, rcont.ron, in->x.f.xfm);
 	for (i = 0; i < 3; i++)
-		r->ron[i] /= in->f.sca;
+		r->ron[i] /= in->x.f.sca;
 	r->rod = rcont.rod;
 					/* return hit */
 	return(1);