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,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 */
32package 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 */
41public 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     */
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     */
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     */
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     */
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     */
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     */
88    public abstract void update();
89
90    /**
91     * Reset the timer to 0. Clear any tpf history.
92     */
93    public abstract void reset();
94}
95