DeltaTimeUtil.java

package com.javamarcher.util;

public class DeltaTimeUtil {
	private static final double NANO_TO_SECOND = 1.0 / 1000000000;
	
	private double deltaTime = 0.0;
	private long last;
	private final long timeAtStart;
	
	public DeltaTimeUtil() {
		last = System.nanoTime();
		timeAtStart = last;
	}
	
	public void calculateDeltaTime() {
		deltaTime = (-last + (last = System.nanoTime())) * NANO_TO_SECOND;
	}
	
	public double getDeltaTime() {
		return deltaTime;
	}
	
	/**
	 * Time since startup. 
	 */
	public double getGlobalTime() {
		final long currentTime = System.nanoTime();
		return (currentTime - timeAtStart) * NANO_TO_SECOND;
	}
}