From 41cd6c47b23975098cd155517790e018670785e7 Mon Sep 17 00:00:00 2001 From: Kenneth Russel Date: Mon, 15 Jun 2009 23:12:27 +0000 Subject: Copied JOGL_2_SANDBOX r350 on to trunk; JOGL_2_SANDBOX branch is now closed git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/../svn-server-sync/jogl-demos/trunk@352 3298f667-5e0e-4b4a-8ed4-a3559d26a5f4 --- src/demos/util/SystemTime.java | 110 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 src/demos/util/SystemTime.java (limited to 'src/demos/util/SystemTime.java') diff --git a/src/demos/util/SystemTime.java b/src/demos/util/SystemTime.java new file mode 100644 index 0000000..b6a154b --- /dev/null +++ b/src/demos/util/SystemTime.java @@ -0,0 +1,110 @@ +/* + * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * - Redistribution of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistribution 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. + * + * Neither the name of Sun Microsystems, Inc. or the names of + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * This software is provided "AS IS," without a warranty of any kind. ALL + * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, + * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A + * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN + * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR + * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR + * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR + * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR + * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE + * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, + * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF + * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. + * + * You acknowledge that this software is not designed or intended for use + * in the design, construction, operation or maintenance of any nuclear + * facility. + * + * Sun gratefully acknowledges that this software was originally authored + * and developed by Kenneth Bradley Russell and Christopher John Kline. + */ + +package demos.util; + +/** Implementation of {@link demos.util.Time} interface based + on {@link java.lang.System.currentTimeMillis}. Performs smoothing + internally to avoid effects of poor granularity of + currentTimeMillis on Windows platform in particular. */ + +public class SystemTime implements Time { + private static final int DEFAULT_NUM_SMOOTHING_SAMPLES = 10; + private long[] samples = new long[DEFAULT_NUM_SMOOTHING_SAMPLES]; + private int numSmoothingSamples; + private int curSmoothingSample; // Index of current sample to be replaced + private long baseTime = System.currentTimeMillis(); + private boolean hasCurTime; + private double curTime; + private double deltaT; + + /** Sets number of smoothing samples. Defaults to 10. Note that + there may be a discontinuity in the reported time after a call + to this method. */ + public void setNumSmoothingSamples(int num) { + samples = new long[num]; + numSmoothingSamples = 0; + curSmoothingSample = 0; + hasCurTime = false; + } + + /** Returns number of smoothing samples; default is 10. */ + public int getNumSmoothingSamples() { + return samples.length; + } + + /** Rebases this timer. After very long periods of time the + resolution of this timer may decrease; the application can call + this to restore higher resolution. Note that there may be a + discontinuity in the reported time after a call to this + method. */ + public void rebase() { + baseTime = System.currentTimeMillis(); + setNumSmoothingSamples(samples.length); + } + + public void update() { + long tmpTime = System.currentTimeMillis(); + long diffSinceBase = tmpTime - baseTime; + samples[curSmoothingSample] = diffSinceBase; + curSmoothingSample = (curSmoothingSample + 1) % samples.length; + numSmoothingSamples = Math.min(1 + numSmoothingSamples, samples.length); + // Average of samples is current time + double newCurTime = 0.0; + for (int i = 0; i < numSmoothingSamples; i++) { + newCurTime += samples[i]; + } + newCurTime /= (1000.0f * numSmoothingSamples); + double lastTime = curTime; + if (!hasCurTime) { + lastTime = newCurTime; + hasCurTime = true; + } + deltaT = newCurTime - lastTime; + curTime = newCurTime; + } + + public double time() { + return curTime; + } + + public double deltaT() { + return deltaT; + } +} -- cgit v1.2.3