--- ray/src/common/face.c	2003/02/22 02:07:22	2.6
+++ ray/src/common/face.c	2003/03/21 18:48:46	2.10
@@ -1,66 +1,11 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: face.c,v 2.6 2003/02/22 02:07:22 greg Exp $";
+static const char RCSid[] = "$Id: face.c,v 2.10 2003/03/21 18:48:46 greg Exp $";
 #endif
 /*
  *  face.c - routines dealing with polygonal faces.
  */
 
-/* ====================================================================
- * 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  "standard.h"
 
@@ -80,9 +25,9 @@ static const char	RCSid[] = "$Id: face.c,v 2.6 2003/02
  */
 
 #ifdef  SMLFLT
-#define  VERTEPS	1e-2		/* allowed vertex error */
+#define  VERTEPS	1e-3		/* allowed vertex error */
 #else
-#define  VERTEPS	1e-4		/* allowed vertex error */
+#define  VERTEPS	1e-5		/* allowed vertex error */
 #endif
 
 
@@ -91,7 +36,7 @@ getface(o)			/* get arguments for a face */
 OBJREC  *o;
 {
 	double  d1;
-	int  badvert;
+	int  smalloff, badvert;
 	FVECT  v1, v2, v3;
 	register FACE  *f;
 	register int  i;
@@ -139,13 +84,17 @@ OBJREC  *o;
 						/* compute offset */
 	badvert = 0;
 	f->offset = DOT(f->norm, VERTEX(f,0));
+	smalloff = fabs(f->offset) <= VERTEPS;
 	for (i = 1; i < f->nv; i++) {
 		d1 = DOT(f->norm, VERTEX(f,i));
-		badvert += fabs(d1 - f->offset/i) > VERTEPS;
+		if (smalloff)
+			badvert += fabs(d1 - f->offset/i) > VERTEPS;
+		else
+			badvert += fabs(1.0 - d1*i/f->offset) > VERTEPS;
 		f->offset += d1;
 	}
 	f->offset /= (double)f->nv;
-	if (badvert)
+	if (f->nv > 3 && badvert)
 		objerror(o, WARNING, "non-planar vertex");
 						/* find axis */
 	f->ax = fabs(f->norm[0]) > fabs(f->norm[1]) ? 0 : 1;
@@ -174,6 +123,7 @@ FACE  *f;
 {
 	int  ncross, n;
 	double  x, y;
+	int  tst;
 	register int  xi, yi;
 	register FLOAT  *p0, *p1;
 
@@ -187,13 +137,15 @@ FACE  *f;
 	ncross = 0;
 					/* positive x axis cross test */
 	while (n--) {
-		if ((p0[yi] > y) ^ (p1[yi] > y))
-			if (p0[xi] > x && p1[xi] > x)
+		if ((p0[yi] > y) ^ (p1[yi] > y)) {
+			tst = (p0[xi] > x) + (p1[xi] > x);
+			if (tst == 2)
 				ncross++;
-			else if (p0[xi] > x || p1[xi] > x)
+			else if (tst)
 				ncross += (p1[yi] > p0[yi]) ^
 						((p0[yi]-y)*(p1[xi]-x) >
 						(p0[xi]-x)*(p1[yi]-y));
+		}
 		p0 = p1;
 		p1 += 3;
 	}