--- ray/src/rt/m_mist.c	2003/03/10 17:26:26	2.12
+++ ray/src/rt/m_mist.c	2014/07/08 18:25:00	2.18
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id";
+static const char RCSid[] = "$Id: m_mist.c,v 2.18 2014/07/08 18:25:00 greg Exp $";
 #endif
 /*
  * Mist volumetric material.
@@ -7,9 +7,11 @@ static const char RCSid[] = "$Id";
 
 #include "copyright.h"
 
-#include  "ray.h"
+#include <string.h>
 
+#include  "ray.h"
 #include  "source.h"
+#include  "rtotypes.h"
 
 /*
  *  A mist volume is used to specify a region in the scene where a certain
@@ -49,13 +51,18 @@ static const char RCSid[] = "$Id";
 
 #define RELAYDELIM	'>'		/* relay delimiter character */
 
+static int inslist(int  *sl, int  n);
+static int srcmatch(SRCREC  *sp, char  *id);
+static void add2slist(RAY  *r, int  *sl);
 
+
 static int
-inslist(sl, n)		/* return index of source n if it's in list sl */
-register int  *sl;
-register int  n;
+inslist(		/* return index of source n if it's in list sl */
+	int  *sl,
+	int  n
+)
 {
-	register int  i;
+	int  i;
 
 	for (i = sl[0]; i > 0; i--)
 		if (sl[i] == n)
@@ -65,13 +72,14 @@ register int  n;
 
 
 static int
-srcmatch(sp, id)	/* check for an id match on a light source */
-register SRCREC  *sp;
-register char  *id;
+srcmatch(	/* check for an id match on a light source */
+	SRCREC  *sp,
+	char  *id
+)
 {
-	register char  *cp;
+	char  *cp;
 						/* check for relay sources */
-	while ((cp = index(id, RELAYDELIM)) != NULL) {
+	while ((cp = strchr(id, RELAYDELIM)) != NULL) {
 		if (!(sp->sflags & SVIRTUAL) || sp->so == NULL)
 			return(0);
 		if (strncmp(id, sp->so->oname, cp-id) || sp->so->oname[cp-id])
@@ -86,12 +94,13 @@ register char  *id;
 
 
 static void
-add2slist(r, sl)	/* add source list to ray's */
-register RAY  *r;
-register int  *sl;
+add2slist(	/* add source list to ray's */
+	RAY  *r,
+	int  *sl
+)
 {
 	static int  slspare[MAXSLIST+1];	/* in case of emergence */
-	register int  i;
+	int  i;
 
 	if (sl == NULL || sl[0] == 0)		/* nothing to add */
 		return;
@@ -108,16 +117,17 @@ register int  *sl;
 
 
 int
-m_mist(m, r)		/* process a ray entering or leaving some mist */
-OBJREC  *m;
-register RAY  *r;
+m_mist(		/* process a ray entering or leaving some mist */
+	OBJREC  *m,
+	RAY  *r
+)
 {
 	RAY  p;
 	int  *myslist = NULL;
 	int  newslist[MAXSLIST+1];
 	COLOR  mext;
 	double  re, ge, be;
-	register int  i, j;
+	int  i, j;
 					/* check arguments */
 	if (m->oargs.nfargs > 7)
 		objerror(m, USER, "bad arguments");
@@ -155,7 +165,7 @@ register RAY  *r;
 	} else
 		setcolor(mext, 0., 0., 0.);
 						/* start transmitted ray */
-	if (rayorigin(&p, r, TRANS, 1.) < 0)
+	if (rayorigin(&p, TRANS, r, NULL) < 0)
 		return(1);
 	VCOPY(p.rdir, r->rdir);
 	p.slights = newslist;
@@ -175,7 +185,7 @@ register RAY  *r;
 	} else {				/* leaving ray */
 		if (myslist != NULL) {			/* delete from list */
 			for (j = myslist[0]; j > 0; j--)
-				if (i = inslist(p.slights, myslist[j]))
+				if ( (i = inslist(p.slights, myslist[j])) )
 					p.slights[i] = -1;
 			for (i = 0, j = 1; j <= p.slights[0]; j++)
 				if (p.slights[j] != -1)
@@ -212,4 +222,5 @@ register RAY  *r;
 	return(1);
 memerr:
 	error(SYSTEM, "out of memory in m_mist");
+	return 0; /* pro forma return */
 }