--- ray/src/rt/t_func.c	1994/01/12 16:46:54	2.3
+++ ray/src/rt/t_func.c	2012/06/09 07:16:47	2.9
@@ -1,18 +1,15 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: t_func.c,v 2.9 2012/06/09 07:16:47 greg Exp $";
 #endif
-
 /*
  *  t_func.c - routine for procedural textures.
- *
- *     4/8/86
  */
 
-#include  "ray.h"
+#include "copyright.h"
 
+#include  "ray.h"
 #include  "func.h"
+#include  "rtotypes.h"
 
 /*
  *	A procedural texture perturbs the surface normal
@@ -31,9 +28,11 @@ static char SCCSid[] = "$SunId$ LBL";
  */
 
 
-t_func(m, r)			/* compute texture for ray */
-register OBJREC  *m;
-register RAY  *r;
+extern int
+t_func(			/* compute texture for ray */
+	register OBJREC  *m,
+	register RAY  *r
+)
 {
 	FVECT  disp;
 	double  d;
@@ -47,19 +46,18 @@ register RAY  *r;
 	errno = 0;
 	for (i = 0; i < 3; i++) {
 		disp[i] = evalue(mf->ep[i]);
-		if (errno) {
+		if (errno == EDOM || errno == ERANGE) {
 			objerror(m, WARNING, "compute error");
 			return(0);
 		}
 	}
-	if (mf->f != &unitxf)
-		multv3(disp, disp, mf->f->xfm);
+	if (mf->fxp != &unitxf)
+		multv3(disp, disp, mf->fxp->xfm);
 	if (r->rox != NULL) {
 		multv3(disp, disp, r->rox->f.xfm);
-		d = 1.0 / (mf->f->sca * r->rox->f.sca);
+		d = 1.0 / (mf->fxp->sca * r->rox->f.sca);
 	} else
-		d = 1.0 / mf->f->sca;
-	for (i = 0; i < 3; i++)
-		r->pert[i] += disp[i] * d;
+		d = 1.0 / mf->fxp->sca;
+	VSUM(r->pert, r->pert, disp, d);
 	return(0);
 }