1 files changed, 102 insertions, 0 deletions
diff --git a/src/libnoiseforjava/module/Spheres.java b/src/libnoiseforjava/module/Spheres.java
new file mode 100644
index 0000000..03b580f
--- /dev/null
+++ b/src/libnoiseforjava/module/Spheres.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2003, 2004 Jason Bevins (original libnoise code)
+ * Copyright  2010 Thomas J. Hodge (java port of libnoise)
+ * 
+ * This file is part of libnoiseforjava.
+ * 
+ * libnoiseforjava is a Java port of the C++ library libnoise, which may be found at 
+ * http://libnoise.sourceforge.net/.  libnoise was developed by Jason Bevins, who may be 
+ * contacted at [email protected] (for great email, take off every 'zig').
+ * Porting to Java was done by Thomas Hodge, who may be contacted at
+ * [email protected] (remove every 'zag').
+ * 
+ * libnoiseforjava is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ * 
+ * libnoiseforjava is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along with
+ * libnoiseforjava.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+package libnoiseforjava.module;
+
+public class Spheres extends ModuleBase
+{
+
+   /// Noise module that outputs concentric spheres.
+   ///
+   /// This noise module outputs concentric spheres centered on the origin
+   /// like the concentric rings of an onion.
+   ///
+   /// The first sphere has a radius of 1.0.  Each subsequent sphere has a
+   /// radius that is 1.0 unit larger than the previous sphere.
+   ///
+   /// The output value from this noise module is determined by the distance
+   /// between the input value and the the nearest spherical surface.  The
+   /// input values that are located on a spherical surface are given the
+   /// output value 1.0 and the input values that are equidistant from two
+   /// spherical surfaces are given the output value -1.0.
+   ///
+   /// An application can change the frequency of the concentric spheres.
+   /// Increasing the frequency reduces the distances between spheres.  To
+   /// specify the frequency, call the setFrequency() method.
+   ///
+   /// This noise module, modified with some low-frequency, low-power
+   /// turbulence, is useful for generating agate-like textures.
+   ///
+   /// This noise module does not require any source modules.
+
+   /// Default frequency value for the Spheres noise module.
+   static final double DEFAULT_SPHERES_FREQUENCY = 1.0;
+
+   /// Frequency of the concentric spheres.
+   double frequency;
+
+
+   public Spheres ()
+   {
+      super(0);
+      frequency = DEFAULT_SPHERES_FREQUENCY;
+   }
+
+   public double getValue (double x, double y, double z)
+   {
+      x *= frequency;
+      y *= frequency;
+      z *= frequency;
+
+      double distFromCenter = Math.sqrt (x * x + y * y + z * z);
+      double distFromSmallerSphere = distFromCenter - Math.floor (distFromCenter);
+      double distFromLargerSphere = 1.0 - distFromSmallerSphere;
+      double nearestDist = Math.min(distFromSmallerSphere, distFromLargerSphere);
+      return 1.0 - (nearestDist * 4.0); // Puts it in the -1.0 to +1.0 range.
+   }
+
+   /// Returns the frequency of the concentric spheres.
+   ///
+   /// @returns The frequency of the concentric spheres.
+   ///
+   /// Increasing the frequency increases the density of the concentric
+   /// spheres, reducing the distances between them.
+   public double getFrequency ()
+   {
+      return frequency;
+   }
+
+   /// Sets the frequency of the concentric spheres.
+   ///
+   /// @param frequency The frequency of the concentric spheres.
+   ///
+   /// Increasing the frequency increases the density of the concentric
+   /// spheres, reducing the distances between them.
+   public void setFrequency (double frequency)
+   {
+      this.frequency = frequency;
+   }
+
+}