--- ray/src/rt/noise3.c	1991/05/24 14:23:33	1.5
+++ ray/src/rt/noise3.c	2003/02/22 02:07:29	2.6
@@ -1,19 +1,71 @@
-/* Copyright (c) 1988 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: noise3.c,v 2.6 2003/02/22 02:07:29 greg Exp $";
 #endif
-
 /*
  *  noise3.c - noise functions for random textures.
  *
  *     Credit for the smooth algorithm goes to Ken Perlin.
  *     (ref. SIGGRAPH Vol 19, No 3, pp 287-96)
+ */
+
+/* ====================================================================
+ * The Radiance Software License, Version 1.0
  *
- *     4/15/86
- *     5/19/88	Added fractal noise function
+ * Copyright (c) 1990 - 2002 The Regents of the University of California,
+ * through Lawrence Berkeley National Laboratory.   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *         notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *           if any, must include the following acknowledgment:
+ *             "This product includes Radiance software
+ *                 (http://radsite.lbl.gov/)
+ *                 developed by the Lawrence Berkeley National Laboratory
+ *               (http://www.lbl.gov/)."
+ *       Alternately, this acknowledgment may appear in the software itself,
+ *       if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
+ *       and "The Regents of the University of California" must
+ *       not be used to endorse or promote products derived from this
+ *       software without prior written permission. For written
+ *       permission, please contact radiance@radsite.lbl.gov.
+ *
+ * 5. Products derived from this software may not be called "Radiance",
+ *       nor may "Radiance" appear in their name, without prior written
+ *       permission of Lawrence Berkeley National Laboratory.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of Lawrence Berkeley National Laboratory.   For more
+ * information on Lawrence Berkeley National Laboratory, please see
+ * <http://www.lbl.gov/>.
  */
 
+#include  <math.h>
 
 #define  A		0
 #define  B		1
@@ -25,21 +77,27 @@ static char SCCSid[] = "$SunId$ LBL";
 #define  rand3c(x,y,z)	frand(89*(x)+97*(y)+101*(z))
 #define  rand3d(x,y,z)	frand(103*(x)+107*(y)+109*(z))
 
-#define  hermite(p0,p1,r0,r1,t)  (	p0*((2.0*t-3.0)*t*t+1.0) + \
-					p1*(-2.0*t+3.0)*t*t + \
-					r0*((t-2.0)*t+1.0)*t + \
-					r1*(t-1.0)*t*t )
+#define  hpoly1(t)	((2.0*t-3.0)*t*t+1.0)
+#define  hpoly2(t)	(-2.0*t+3.0)*t*t
+#define  hpoly3(t)	((t-2.0)*t+1.0)*t
+#define  hpoly4(t)	(t-1.0)*t*t
 
-static char  *noise_name[4] = {"noise3a", "noise3b", "noise3c", "noise3"};
+#define  hermite(p0,p1,r0,r1,t)  (	p0*hpoly1(t) + \
+					p1*hpoly2(t) + \
+					r0*hpoly3(t) + \
+					r1*hpoly4(t) )
+
+static char  noise_name[4][8] = {"noise3x", "noise3y", "noise3z", "noise3"};
 static char  fnoise_name[] = "fnoise3";
 static char  hermite_name[] = "hermite";
 
 double  *noise3(), fnoise3(), argument(), frand();
+static  interpolate();
 
 static long  xlim[3][2];
 static double  xarg[3];
 
-#define  EPSILON	.0001		/* error allowed in fractal */
+#define  EPSILON	.001		/* error allowed in fractal */
 
 #define  frand3(x,y,z)	frand(17*(x)+23*(y)+29*(z))
 
@@ -61,7 +119,8 @@ register char  *nam;
 	while (i--)
 		if (nam == noise_name[i])
 			return(noise3(x)[i]);
-	eputs("Bad call to l_noise3()!\n");
+	eputs(nam);
+	eputs(": called l_noise3!\n");
 	quit(1);
 }
 
@@ -93,7 +152,6 @@ double *
 noise3(xnew)			/* compute the noise function */
 register double  xnew[3];
 {
-	extern double  floor();
 	static double  x[3] = {-100000.0, -100000.0, -100000.0};
 	static double  f[4];
 
@@ -116,7 +174,7 @@ interpolate(f, i, n)
 double  f[4];
 register int  i, n;
 {
-	double  f0[4], f1[4];
+	double  f0[4], f1[4], hp1, hp2;
 
 	if (n == 0) {
 		f[A] = rand3a(xlim[0][i&1],xlim[1][i>>1&1],xlim[2][i>>2]);
@@ -127,10 +185,12 @@ register int  i, n;
 		n--;
 		interpolate(f0, i, n);
 		interpolate(f1, i | 1<<n, n);
-		f[A] = (1.0-xarg[n])*f0[A] + xarg[n]*f1[A];
-		f[B] = (1.0-xarg[n])*f0[B] + xarg[n]*f1[B];
-		f[C] = (1.0-xarg[n])*f0[C] + xarg[n]*f1[C];
-		f[D] = hermite(f0[D], f1[D], f0[n], f1[n], xarg[n]);
+		hp1 = hpoly1(xarg[n]); hp2 = hpoly2(xarg[n]);
+		f[A] = f0[A]*hp1 + f1[A]*hp2;
+		f[B] = f0[B]*hp1 + f1[B]*hp2;
+		f[C] = f0[C]*hp1 + f1[C]*hp2;
+		f[D] = f0[D]*hp1 + f1[D]*hp2 +
+				f0[n]*hpoly3(xarg[n]) + f1[n]*hpoly4(xarg[n]);
 	}
 }
 
@@ -148,7 +208,6 @@ double
 fnoise3(p)			/* compute fractal noise function */
 double  p[3];
 {
-	double  floor();
 	long  t[3], v[3], beg[3];
 	double  fval[8], fc;
 	int  branch;