--- ray/src/rt/rvmain.c	2023/01/24 21:54:49	2.18
+++ ray/src/rt/rvmain.c	2024/01/18 00:28:54	2.21
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: rvmain.c,v 2.18 2023/01/24 21:54:49 greg Exp $";
+static const char	RCSid[] = "$Id: rvmain.c,v 2.21 2024/01/18 00:28:54 greg Exp $";
 #endif
 /*
  *  rvmain.c - main for rview interactive viewer
@@ -191,6 +191,10 @@ main(int argc, char *argv[])
 			goto badopt;
 		}
 	}
+					/* set/check spectral sampling */
+	if (setspectrsamp(CNDX, WLPART) <= 0)
+		error(USER, "unsupported spectral sampling");
+
 	err = setview(&ourview);	/* set viewing parameters */
 	if (err != NULL)
 		error(USER, err);
@@ -257,7 +261,7 @@ badopt:
 
 void
 wputs(				/* warning output function */
-	char	*s
+	const char	*s
 )
 {
 	int  lasterrno = errno;
@@ -268,7 +272,7 @@ wputs(				/* warning output function */
 
 void
 eputs(				/* put string to stderr */
-	char  *s
+	const char  *s
 )
 {
 	static int  midline = 0;