--- ray/src/rt/o_cone.c	2003/02/22 02:07:29	2.2
+++ ray/src/rt/o_cone.c	2010/10/25 22:57:45	2.7
@@ -1,77 +1,23 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: o_cone.c,v 2.2 2003/02/22 02:07:29 greg Exp $";
+static const char RCSid[] = "$Id: o_cone.c,v 2.7 2010/10/25 22:57:45 greg Exp $";
 #endif
 /*
  *  o_cone.c - routine to determine ray intersection with cones.
  */
 
-/* ====================================================================
- * The Radiance Software License, Version 1.0
- *
- * 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 "copyright.h"
 
 #include  "ray.h"
-
 #include  "otypes.h"
-
+#include  "rtotypes.h"
 #include  "cone.h"
 
 
-o_cone(o, r)			/* intersect ray with cone */
-OBJREC  *o;
-register RAY  *r;
+extern int
+o_cone(			/* intersect ray with cone */
+	OBJREC  *o,
+	register RAY  *r
+)
 {
 	FVECT  rox, rdx;
 	double  a, b, c;
@@ -134,8 +80,7 @@ register RAY  *r;
 			return(0);			/* outside radii */
 		r->ro = o;
 		r->rot = root[0];
-		for (i = 0; i < 3; i++)
-			r->rop[i] = r->rorg[i] + r->rdir[i]*r->rot;
+		VSUM(r->rop, r->rorg, r->rdir, r->rot);
 		VCOPY(r->ron, co->ad);
 		r->rod = -rdx[2];
 		r->rox = NULL;
@@ -150,10 +95,8 @@ register RAY  *r;
 		if (root[rn] >= r->rot)
 			break;			/* too big */
 						/* check endpoints */
-		for (i = 0; i < 3; i++) {
-			rox[i] = r->rorg[i] + root[rn]*r->rdir[i];
-			rdx[i] = rox[i] - CO_P0(co)[i];
-		}
+		VSUM(rox, r->rorg, r->rdir, root[rn]);
+		VSUB(rdx, rox, CO_P0(co));
 		b = DOT(rdx, co->ad); 
 		if (b < 0.0)
 			continue;		/* before p0 */
@@ -180,8 +123,15 @@ register RAY  *r;
 		if (o->otype == OBJ_CONE || o->otype == OBJ_CUP)
 			for (i = 0; i < 3; i++)
 				r->ron[i] = (co->al*r->ron[i] - c*co->ad[i])
-						/co->sl;
+						/ co->sl;
+		a = DOT(r->ron, r->ron);
+		if (a > 1.+FTINY || a < 1.-FTINY) {
+			c = 1./(.5 + .5*a);     /* avoid numerical error */
+			r->ron[0] *= c; r->ron[1] *= c; r->ron[2] *= c;
+		}
 		r->rod = -DOT(r->rdir, r->ron);
+		r->pert[0] = r->pert[1] = r->pert[2] = 0.0;
+		r->uv[0] = r->uv[1] = 0.0;
 		r->rox = NULL;
 		return(1);			/* good */
 	}