--- ray/src/rt/func.c	1992/02/05 09:23:38	2.5
+++ ray/src/rt/func.c	1993/05/25 10:30:16	2.9
@@ -23,10 +23,10 @@ static char SCCSid[] = "$SunId$ LBL";
 #define  LCALSUF	4
 
 XF  unitxf = {			/* identity transform */
-	1.0, 0.0, 0.0, 0.0,
-	0.0, 1.0, 0.0, 0.0,
-	0.0, 0.0, 1.0, 0.0,
-	0.0, 0.0, 0.0, 1.0,
+	{{1.0, 0.0, 0.0, 0.0},
+	{0.0, 1.0, 0.0, 0.0},
+	{0.0, 0.0, 1.0, 0.0},
+	{0.0, 0.0, 0.0, 1.0}},
 	1.0
 };
 
@@ -54,12 +54,13 @@ int  dofwd;
 					/* check to see if done already */
 	if ((f = (MFUNC *)m->os) != NULL)
 		return(f);
+	fobj = NULL; fray = NULL;
 	if (initfile[0]) {		/* initialize on first call */
 		setcontext("");
 		scompile("Dx=$1;Dy=$2;Dz=$3;", NULL, 0);
 		scompile("Nx=$4;Ny=$5;Nz=$6;", NULL, 0);
 		scompile("Px=$7;Py=$8;Pz=$9;", NULL, 0);
-		scompile("T=$10;Rdot=$11;", NULL, 0);
+		scompile("T=$10;Ts=$25;Rdot=$11;", NULL, 0);
 		scompile("S=$12;Tx=$13;Ty=$14;Tz=$15;", NULL, 0);
 		scompile("Ix=$16;Iy=$17;Iz=$18;", NULL, 0);
 		scompile("Jx=$19;Jy=$20;Jz=$21;", NULL, 0);
@@ -165,7 +166,7 @@ setfunc(m, r)			/* set channels for function call */
 OBJREC  *m;
 register RAY  *r;
 {
-	static long  lastrno = -1;
+	static unsigned long  lastrno = ~0;
 	register MFUNC  *f;
 					/* get function */
 	if ((f = (MFUNC *)m->os) == NULL)
@@ -211,6 +212,9 @@ l_arg()				/* return nth real argument */
 	extern double  argument();
 	register int  n;
 
+	if (fobj == NULL)
+		syntax("arg(n) used in constant expression");
+
 	n = argument(1) + .5;		/* round to integer */
 
 	if (n < 1)
@@ -249,6 +253,9 @@ register int  n;
 	double  sum;
 	register RAY  *r;
 
+	if (fray == NULL)
+		syntax("ray parameter used in constant expression");
+
 	if (--n < 0)
 		goto badchan;
 
@@ -273,14 +280,14 @@ register int  n;
 				fray->rop[2]*funcxf.xfm[2][n-6] +
 					     funcxf.xfm[3][n-6] );
 
-	if (n == 9) {			/* distance */
-
+	if (n == 9) {			/* total distance */
 		sum = fray->rot;
 		for (r = fray->parent; r != NULL; r = r->parent)
 			sum += r->rot;
 		return(sum * funcxf.sca);
 
 	}
+
 	if (n == 10)			/* dot product (range [-1,1]) */
 		return(	fray->rod <= -1.0 ? -1.0 :
 			fray->rod >= 1.0 ? 1.0 :
@@ -300,6 +307,14 @@ register int  n;
 
 	if (n < 24)			/* k unit vector */
 		return(funcxf.xfm[2][n-21] / funcxf.sca);
+
+	if (n == 24) {			/* single ray (shadow) distance */
+		sum = fray->rot;
+		for (r = fray->parent; r != NULL && r->crtype&SHADOW;
+				r = r->parent)
+			sum += r->rot;
+		return(sum * funcxf.sca);
+	}
 badchan:
 	error(USER, "illegal channel number");
 }