--- ray/src/rt/m_mirror.c	2003/02/22 02:07:28	2.8
+++ ray/src/rt/m_mirror.c	2014/05/10 17:43:01	2.16
@@ -1,71 +1,15 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: m_mirror.c,v 2.8 2003/02/22 02:07:28 greg Exp $";
+static const char	RCSid[] = "$Id: m_mirror.c,v 2.16 2014/05/10 17:43:01 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 "copyright.h"
 
 #include  "ray.h"
-
 #include  "otypes.h"
-
+#include  "rtotypes.h"
 #include  "source.h"
 
 /*
@@ -79,26 +23,28 @@ static const char	RCSid[] = "$Id: m_mirror.c,v 2.8 200
  * part of the direct calculation.
  */
 
+static int mir_proj(MAT4  pm, OBJREC  *o, SRCREC  *s, int  n);
+static void mirrorproj(MAT4  m, FVECT  nv, double  offs);
 
-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;
+m_mirror(			/* shade mirrored ray */
+	OBJREC  *m,
+	RAY  *r
+)
 {
 	COLOR  mcolor;
 	RAY  nr;
 	int  rpure = 1;
-	register int  i;
+	int  i;
 					/* check arguments */
 	if (m->oargs.nfargs != 3 || m->oargs.nsargs > 1)
 		objerror(m, USER, "bad number of arguments");
 					/* check for substitute material */
-	if (m->oargs.nsargs > 0 &&
+					/* but avoid double-counting */
+	if (m->oargs.nsargs > 0 && !(r->crtype & (AMBIENT|SPECULAR)) &&
 			(r->rsrc < 0 || source[r->rsrc].so != r->ro)) {
 		if (!strcmp(m->oargs.sarg[0], VOIDID)) {
 			raytrans(r);
@@ -110,8 +56,11 @@ register RAY  *r;
 	if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
 		return(1);
 
-	if (r->rod < 0.)		/* back is black */
+	if (r->rod < 0.) {		/* back is black */
+		if (!backvis)
+			raytrans(r);	/* unless back visibility is off */
 		return(1);
+	}
 					/* get modifiers */
 	raytexture(r, m->omod);
 					/* assign material color */
@@ -121,7 +70,7 @@ register RAY  *r;
 	multcolor(mcolor, r->pcol);
 					/* compute reflected ray */
 	if (r->rsrc >= 0) {			/* relayed light source */
-		rayorigin(&nr, r, REFLECTED, 1.);
+		rayorigin(&nr, REFLECTED, r, mcolor);
 					/* ignore textures */
 		for (i = 0; i < 3; i++)
 			nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
@@ -131,9 +80,10 @@ register RAY  *r;
 		FVECT  pnorm;
 		double  pdot;
 
-		if (rayorigin(&nr, r, REFLECTED, bright(mcolor)) < 0)
+		if (rayorigin(&nr, REFLECTED, r, mcolor) < 0)
 			return(1);
-		if (DOT(r->pert,r->pert) > FTINY*FTINY) {
+		if (!(r->crtype & AMBIENT) &&
+				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];
@@ -144,8 +94,9 @@ register RAY  *r;
 			for (i = 0; i < 3; i++)
 				nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
 	}
+	checknorm(nr.rdir);
 	rayvalue(&nr);
-	multcolor(nr.rcol, mcolor);
+	multcolor(nr.rcol, nr.rcoef);
 	addcolor(r->rcol, nr.rcol);
 	if (rpure && r->ro != NULL && isflat(r->ro->otype))
 		r->rt = r->rot + nr.rt;
@@ -154,27 +105,35 @@ register RAY  *r;
 
 
 static int
-mir_proj(pm, o, s, n)		/* compute a mirror's projection */
-MAT4  pm;
-register OBJREC  *o;
-SRCREC  *s;
-int  n;
+mir_proj(		/* compute a mirror's projection */
+	MAT4  pm,
+	OBJREC  *o,
+	SRCREC  *s,
+	int  n
+)
 {
+	double	corr = 1.;
 	FVECT  nv, sc;
-	double  od;
-	register int  i, j;
+	double  od, offs;
+	int  i;
 				/* get surface normal and offset */
-	od = getplaneq(nv, o);
-				/* check for extreme point for behind */
+	offs = od = getplaneq(nv, o);
+	if (s->sflags & SDISTANT)
+		offs = 0.;
+				/* check for extreme point behind */
+	if (s->sflags & SCIR) {
+		if (s->sflags & (SFLAT|SDISTANT))
+			corr = 1.12837917;	/* correct setflatss() */
+		else
+			corr = 1.0/0.7236;	/* correct sphsetsrc() */
+	}
 	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];
+		if (DOT(nv, s->ss[i]) > offs)
+			VSUM(sc, sc, s->ss[i], corr);
 		else
-			for (j = 0; j < 3; j++)
-				sc[j] -= s->ss[i][j];
-	if (DOT(sc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY))
+			VSUM(sc, sc, s->ss[i], -corr);
+	if (DOT(sc, nv) <= offs+FTINY)
 		return(0);
 				/* everything OK -- compute projection */
 	mirrorproj(pm, nv, od);
@@ -182,13 +141,14 @@ int  n;
 }
 
 
-static int
-mirrorproj(m, nv, offs)		/* get mirror projection for surface */
-register MAT4  m;
-FVECT  nv;
-double  offs;
+static void
+mirrorproj(		/* get mirror projection for surface */
+	MAT4  m,
+	FVECT  nv,
+	double  offs
+)
 {
-	register int  i, j;
+	int  i, j;
 					/* assign matrix */
 	setident4(m);
 	for (j = 0; j < 3; j++) {