jMonkeyEngine/engine/src/core/com/jme3/system/Timer.java

/*
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package com.jme3.system;

/**
 * <code>Timer</code> is the base class for a high resolution timer. It is
 * created from getTimer("display system")
 *
 * @author Mark Powell
 * @version $Id: Timer.java,v 1.18 2007/03/09 10:19:34 rherlitz Exp $
 */
public abstract class Timer {

    /**
     * Returns the current time in ticks. A tick is an arbitrary measure of time
     * defined by the timer implementation. The number of ticks per second is
     * given by <code>getResolution()</code>. The timer starts at 0 ticks.
     *
     * @return a long value representing the current time
     */
    public abstract long getTime();

    /**
     * Returns the time in seconds. The timer starts
     * at 0.0 seconds.
     *
     * @return the current time in seconds
     */
    public float getTimeInSeconds() {
        return getTime() / (float) getResolution();
    }

    /**
     * Returns the resolution of the timer.
     *
     * @return the number of timer ticks per second
     */
    public abstract long getResolution();

    /**
     * Returns the "calls per second". If this is called every frame, then it
     * will return the "frames per second".
     *
     * @return The "calls per second".
     */
    public abstract float getFrameRate();

    /**
     * Returns the time, in seconds, between the last call and the current one.
     *
     * @return Time between this call and the last one.
     */
    public abstract float getTimePerFrame();

    /**
     * <code>update</code> recalculates the frame rate based on the previous
     * call to update. It is assumed that update is called each frame.
     */
    public abstract void update();

    /**
     * Reset the timer to 0. Clear any tpf history.
     */
    public abstract void reset();
}