--- ray/src/rt/mx_data.c	1999/01/20 14:10:06	2.5
+++ ray/src/rt/mx_data.c	2014/07/08 18:25:00	2.10
@@ -1,20 +1,16 @@
-/* Copyright (c) 1998 Silicon Graphics, Inc. */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ SGI";
+static const char	RCSid[] = "$Id: mx_data.c,v 2.10 2014/07/08 18:25:00 greg Exp $";
 #endif
-
 /*
  *  mx_data.c - routine for stored mixtures.
- *
- *     11/2/88
  */
 
-#include  "ray.h"
+#include "copyright.h"
 
+#include  "ray.h"
 #include  "data.h"
-
 #include  "func.h"
+#include  "rtotypes.h"
 
 /*
  *  A stored mixture is specified:
@@ -45,17 +41,19 @@ static char SCCSid[] = "$SunId$ SGI";
  */
 
 
-mx_data(m, r)			/* interpolate mixture data */
-register OBJREC  *m;
-RAY  *r;
+int
+mx_data(			/* interpolate mixture data */
+	OBJREC  *m,
+	RAY  *r
+)
 {
 	OBJECT	obj;
 	double  coef;
 	double  pt[MAXDIM];
 	DATARRAY  *dp;
 	OBJECT  mod[2];
-	register MFUNC  *mf;
-	register int  i;
+	MFUNC  *mf;
+	int  i;
 
 	if (m->oargs.nsargs < 6)
 		objerror(m, USER, "bad # arguments");
@@ -75,13 +73,13 @@ RAY  *r;
 	errno = 0;
 	for (i = 0; i < dp->nd; i++) {
 		pt[i] = evalue(mf->ep[i]);
-		if (errno)
+		if (errno == EDOM || errno == ERANGE)
 			goto computerr;
 	}
 	coef = datavalue(dp, pt);
 	errno = 0;
 	coef = funvalue(m->oargs.sarg[2], 1, &coef);
-	if (errno)
+	if (errno == EDOM || errno == ERANGE)
 		goto computerr;
 	if (raymixture(r, mod[0], mod[1], coef)) {
 		if (m->omod != OVOID)
@@ -95,17 +93,19 @@ computerr:
 }
 
 
-mx_pdata(m, r)			/* interpolate mixture picture */
-register OBJREC  *m;
-RAY  *r;
+int
+mx_pdata(			/* interpolate mixture picture */
+	OBJREC  *m,
+	RAY  *r
+)
 {
 	OBJECT	obj;
 	double	col[3], coef;
 	double  pt[MAXDIM];
 	DATARRAY  *dp;
 	OBJECT  mod[2];
-	register MFUNC  *mf;
-	register int  i;
+	MFUNC  *mf;
+	int  i;
 
 	if (m->oargs.nsargs < 7)
 		objerror(m, USER, "bad # arguments");
@@ -124,13 +124,13 @@ RAY  *r;
 	errno = 0;
 	pt[1] = evalue(mf->ep[0]);	/* y major ordering */
 	pt[0] = evalue(mf->ep[1]);
-	if (errno)
+	if (errno == EDOM || errno == ERANGE)
 		goto computerr;
 	for (i = 0; i < 3; i++)		/* get pixel from picture */
 		col[i] = datavalue(dp+i, pt);
 	errno = 0;			/* evaluate function on pixel */
 	coef = funvalue(m->oargs.sarg[2], 3, col);
-	if (errno)
+	if (errno == EDOM || errno == ERANGE)
 		goto computerr;
 	if (raymixture(r, mod[0], mod[1], coef)) {
 		if (m->omod != OVOID)