--- ray/src/rt/ambio.c	1992/07/16 12:08:47	2.2
+++ ray/src/rt/ambio.c	2003/02/25 02:47:22	2.5
@@ -1,16 +1,15 @@
-/* Copyright (c) 1992 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: ambio.c,v 2.5 2003/02/25 02:47:22 greg Exp $";
 #endif
-
 /*
  * Read and write portable ambient values
+ *
+ *  Declarations of external symbols in ambient.h
  */
 
-#include <stdio.h>
+#include "copyright.h"
 
-#include "color.h"
+#include "ray.h"
 
 #include "ambient.h"
 
@@ -19,11 +18,13 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #define  getvec(v,fp)	(v)[0]=getflt(fp);(v)[1]=getflt(fp);(v)[2]=getflt(fp)
 
+#define  badflt(x)	((x) < -FHUGE || (x) > FHUGE)
 
-extern double  getflt();
-extern long  getint();
+#define  badvec(v)	(badflt((v)[0]) || badflt((v)[1]) || badflt((v)[2]))
 
 
+
+void
 putambmagic(fp)			/* write out ambient value magic number */
 FILE  *fp;
 {
@@ -31,6 +32,7 @@ FILE  *fp;
 }
 
 
+int
 hasambmagic(fp)			/* read in and check validity of magic # */
 FILE  *fp;
 {
@@ -43,6 +45,7 @@ FILE  *fp;
 }
 
 
+int
 writambval(av, fp)		/* write ambient value to stream */
 register AMBVAL  *av;
 FILE  *fp;
@@ -63,6 +66,32 @@ FILE  *fp;
 }
 
 
+int
+ambvalOK(av)			/* check consistency of ambient value */
+register AMBVAL  *av;
+{
+	double	d;
+
+	if (badvec(av->pos)) return(0);
+	if (badvec(av->dir)) return(0);
+	d = DOT(av->dir,av->dir);
+	if (d < 0.9999 || d > 1.0001) return(0);
+	if (av->lvl < 0 || av->lvl > 100) return(0);
+	if (av->weight <= 0. || av->weight > 1.) return(0);
+	if (av->rad <= 0. || av->rad >= FHUGE) return(0);
+	if (colval(av->val,RED) < 0. ||
+			colval(av->val,RED) > FHUGE ||
+			colval(av->val,GRN) < 0. ||
+			colval(av->val,GRN) > FHUGE ||
+			colval(av->val,BLU) < 0. ||
+			colval(av->val,BLU) > FHUGE) return(0);
+	if (badvec(av->gpos)) return(0);
+	if (badvec(av->gdir)) return(0);
+	return(1);
+}
+
+
+int
 readambval(av, fp)		/* read ambient value from stream */
 register AMBVAL  *av;
 FILE  *fp;
@@ -81,5 +110,5 @@ FILE  *fp;
 	av->rad = getflt(fp);
 	getvec(av->gpos, fp);
 	getvec(av->gdir, fp);
-	return(feof(fp) ? 0 : 1);
+	return(feof(fp) ? 0 : ambvalOK(av));
 }