1 /*
2  * Copyright (c) 2009-2010 jMonkeyEngine
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are
7  * met:
8  *
9  * * Redistributions of source code must retain the above copyright
10  *   notice, this list of conditions and the following disclaimer.
11  *
12  * * Redistributions in binary form must reproduce the above copyright
13  *   notice, this list of conditions and the following disclaimer in the
14  *   documentation and/or other materials provided with the distribution.
15  *
16  * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
17  *   may be used to endorse or promote products derived from this software
18  *   without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 package com.jme3.system;
33 
34 /**
35  * <code>Timer</code> is the base class for a high resolution timer. It is
36  * created from getTimer("display system")
37  *
38  * @author Mark Powell
39  * @version $Id: Timer.java,v 1.18 2007/03/09 10:19:34 rherlitz Exp $
40  */
41 public abstract class Timer {
42 
43     /**
44      * Returns the current time in ticks. A tick is an arbitrary measure of time
45      * defined by the timer implementation. The number of ticks per second is
46      * given by <code>getResolution()</code>. The timer starts at 0 ticks.
47      *
48      * @return a long value representing the current time
49      */
getTime()50     public abstract long getTime();
51 
52     /**
53      * Returns the time in seconds. The timer starts
54      * at 0.0 seconds.
55      *
56      * @return the current time in seconds
57      */
getTimeInSeconds()58     public float getTimeInSeconds() {
59         return getTime() / (float) getResolution();
60     }
61 
62     /**
63      * Returns the resolution of the timer.
64      *
65      * @return the number of timer ticks per second
66      */
getResolution()67     public abstract long getResolution();
68 
69     /**
70      * Returns the "calls per second". If this is called every frame, then it
71      * will return the "frames per second".
72      *
73      * @return The "calls per second".
74      */
getFrameRate()75     public abstract float getFrameRate();
76 
77     /**
78      * Returns the time, in seconds, between the last call and the current one.
79      *
80      * @return Time between this call and the last one.
81      */
getTimePerFrame()82     public abstract float getTimePerFrame();
83 
84     /**
85      * <code>update</code> recalculates the frame rate based on the previous
86      * call to update. It is assumed that update is called each frame.
87      */
update()88     public abstract void update();
89 
90     /**
91      * Reset the timer to 0. Clear any tpf history.
92      */
reset()93     public abstract void reset();
94 }
95