--- ray/src/rt/func.c	1991/05/24 13:52:10	1.15
+++ ray/src/rt/func.c	1991/08/08 13:08:01	1.21
@@ -15,6 +15,9 @@ static char SCCSid[] = "$SunId$ LBL";
 #include  "otypes.h"
 
 
+#define  INITFILE	"rayinit.cal"
+#define  DEFVNAME	"FILE_LOADED`"
+
 XF  unitxf = {			/* identity transform */
 	1.0, 0.0, 0.0, 0.0,
 	0.0, 1.0, 0.0, 0.0,
@@ -33,24 +36,11 @@ OBJREC  *m;
 register RAY  *r;
 XF  *bx;
 {
-	extern double  l_arg();
 	extern long  eclock;
-	static char  *initfile = "rayinit.cal";
-					/* initialize if first call */
-	if (initfile != NULL) {
-		loadfunc(initfile);
-		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("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);
-		scompile("Kx=$22;Ky=$23;Kz=$24;", NULL, 0);
-		funset("arg", 1, '=', l_arg);
-		setnoisefuncs();
-		initfile = NULL;
-	}
+	static long  lastrno = -1;
+					/* check to see if already set */
+	if (m == fobj && r->rno == lastrno)
+		return(0);
 	fobj = m;
 	fray = r;
 	if (r->rox != NULL)
@@ -61,7 +51,9 @@ XF  *bx;
 			copystruct(&funcxf, &r->rox->b);
 	else
 		copystruct(&funcxf, bx);
+	lastrno = r->rno;
 	eclock++;		/* notify expression evaluator */
+	return(1);
 }
 
 
@@ -91,8 +83,7 @@ RAY  *r;
 		}
 		m->os = (char *)mxf;
 	}
-	setmap(m, r, mxf);
-	return;
+	return(setmap(m, r, mxf));
 memerr:
 	error(SYSTEM, "out of memory in setfunc");
 }
@@ -132,6 +123,55 @@ l_arg()				/* return nth real argument */
 
 
 double
+l_erf()				/* error function */
+{
+	extern double  erf();
+
+	return(erf(argument(1)));
+}
+
+
+double
+l_erfc()			/* cumulative error function */
+{
+	extern double  erfc();
+
+	return(erfc(argument(1)));
+}
+
+
+funcfile(fname)			/* set context, load file if necessary */
+char  *fname;
+{
+	extern char  *setcontext();
+	static char  initfile[] = INITFILE;
+
+	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("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);
+		scompile("Kx=$22;Ky=$23;Kz=$24;", NULL, 0);
+		funset("arg", 1, '=', l_arg);
+		funset("erf", 1, ':', l_erf);
+		funset("erfc", 1, ':', l_erfc);
+		setnoisefuncs();
+		loadfunc(initfile);
+		initfile[0] = '\0';
+	}
+	setcontext(fname);
+	if (!vardefined(DEFVNAME)) {
+		loadfunc(fname);
+		varset(DEFVNAME, ':', 1.0);
+	}
+}
+
+
+double
 chanvalue(n)			/* return channel n to calcomp */
 register int  n;
 {
@@ -170,8 +210,10 @@ register int  n;
 		return(sum * funcxf.sca);
 
 	}
-	if (n == 10)			/* dot product */
-		return(fray->rod);
+	if (n == 10)			/* dot product (range [-1,1]) */
+		return(	fray->rod <= -1.0 ? -1.0 :
+			fray->rod >= 1.0 ? 1.0 :
+			fray->rod );
 
 	if (n == 11)			/* scale */
 		return(funcxf.sca);