--- ray/src/rt/m_mirror.c	1994/01/12 16:46:41	2.3
+++ ray/src/rt/m_mirror.c	2003/02/22 02:07:28	2.8
@@ -1,13 +1,67 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: m_mirror.c,v 2.8 2003/02/22 02:07:28 greg Exp $";
 #endif
-
 /*
  * Routines for mirror material supporting virtual light sources
  */
 
+/* ====================================================================
+ * 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  "ray.h"
 
 #include  "otypes.h"
@@ -26,16 +80,19 @@ static char SCCSid[] = "$SunId$ LBL";
  */
 
 
-int  mir_proj();
+static int  mir_proj(), mirrorproj();
+
 VSMATERIAL  mirror_vs = {mir_proj, 1};
 
 
+int
 m_mirror(m, r)			/* shade mirrored ray */
 register OBJREC  *m;
 register RAY  *r;
 {
 	COLOR  mcolor;
 	RAY  nr;
+	int  rpure = 1;
 	register int  i;
 					/* check arguments */
 	if (m->oargs.nfargs != 3 || m->oargs.nsargs > 1)
@@ -43,8 +100,11 @@ register RAY  *r;
 					/* check for substitute material */
 	if (m->oargs.nsargs > 0 &&
 			(r->rsrc < 0 || source[r->rsrc].so != r->ro)) {
-		rayshade(r, modifier(m->oargs.sarg[0]));
-		return(1);
+		if (!strcmp(m->oargs.sarg[0], VOIDID)) {
+			raytrans(r);
+			return(1);
+		}
+		return(rayshade(r, lastmod(objndx(m), m->oargs.sarg[0])));
 	}
 					/* check for bad source ray */
 	if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
@@ -73,33 +133,48 @@ register RAY  *r;
 
 		if (rayorigin(&nr, r, REFLECTED, bright(mcolor)) < 0)
 			return(1);
-		pdot = raynormal(pnorm, r);	/* use textures */
-		for (i = 0; i < 3; i++)
-			nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i];
+		if (DOT(r->pert,r->pert) > FTINY*FTINY) {
+			pdot = raynormal(pnorm, r);	/* use textures */
+			for (i = 0; i < 3; i++)
+				nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i];
+			rpure = 0;
+		}
 						/* check for penetration */
-		if (DOT(nr.rdir, r->ron) <= FTINY)
+		if (rpure || DOT(nr.rdir, r->ron) <= FTINY)
 			for (i = 0; i < 3; i++)
 				nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
 	}
 	rayvalue(&nr);
 	multcolor(nr.rcol, mcolor);
 	addcolor(r->rcol, nr.rcol);
+	if (rpure && r->ro != NULL && isflat(r->ro->otype))
+		r->rt = r->rot + nr.rt;
 	return(1);
 }
 
 
+static int
 mir_proj(pm, o, s, n)		/* compute a mirror's projection */
 MAT4  pm;
 register OBJREC  *o;
 SRCREC  *s;
 int  n;
 {
-	FVECT  nv;
+	FVECT  nv, sc;
 	double  od;
+	register int  i, j;
 				/* get surface normal and offset */
 	od = getplaneq(nv, o);
-				/* check for behind */
-	if (DOT(s->sloc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY))
+				/* check for extreme point for behind */
+	VCOPY(sc, s->sloc);
+	for (i = s->sflags & SFLAT ? SV : SW; i >= 0; i--)
+		if (DOT(nv, s->ss[i]) > 0.)
+			for (j = 0; j < 3; j++)
+				sc[j] += s->ss[i][j];
+		else
+			for (j = 0; j < 3; j++)
+				sc[j] -= s->ss[i][j];
+	if (DOT(sc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY))
 		return(0);
 				/* everything OK -- compute projection */
 	mirrorproj(pm, nv, od);
@@ -107,6 +182,7 @@ int  n;
 }
 
 
+static int
 mirrorproj(m, nv, offs)		/* get mirror projection for surface */
 register MAT4  m;
 FVECT  nv;