Behold, Nenya, Ring of Water and repository for our media and animation related

goodies, both Java 2D and LWJGL/JME 3D.


git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@1 ed5b42cb-e716-0410-a449-f6a68f950b19

src/java/com/threerings/media/util/TrailingAverage.java

@@ -0,0 +1,81 @@
+//
+// $Id: TrailingAverage.java 4191 2006-06-13 22:42:20Z ray $
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2004 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.media.util;
+
+/**
+ * Used to compute a trailing average of a value.
+ */
+public class TrailingAverage
+{
+    /**
+     * Creates a trailing average instance with the default number of
+     * values used to compute the average (10).
+     */
+    public TrailingAverage ()
+    {
+        this(10);
+    }
+
+    /**
+     * Creates a trailing average instance with the specified number of
+     * values used to compute the average.
+     */
+    public TrailingAverage (int history)
+    {
+        _history = new int[history];
+    }
+
+    /**
+     * Records a new value.
+     */
+    public void record (int value)
+    {
+        _history[_index++%_history.length] = value;
+    }
+
+    /**
+     * Returns the current averaged value.
+     */
+    public int value ()
+    {
+        int end = Math.min(_history.length, _index);
+        int value = 0;
+        for (int ii = 0; ii < end; ii++) {
+            value += _history[ii];
+        }
+        return (end > 0) ? (value/end) : 0;
+    }
+
+    /**
+     * Returns the current trailing average value as a string.
+     */
+    public String toString ()
+    {
+        return Integer.toString(value());
+    }
+
+    /** The history of values. */
+    protected int[] _history;
+
+    /** The index where we will next record a value. */
+    protected int _index;
+}