#region Copyright & License Information
/*
 * Copyright 2007,2009,2010 Chris Forbes, Robert Pepperell, Matthew Bowra-Dean, Paul Chote, Alli Witheford.
 * This file is part of OpenRA.
 * 
 *  OpenRA is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  OpenRA is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with OpenRA.  If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System.Runtime.InteropServices;

namespace OpenRa.Support
{
	public class Stopwatch
	{
		[DllImport("kernel32.dll")]
		static extern bool QueryPerformanceCounter(out long value);
		[DllImport("kernel32.dll")]
		static extern bool QueryPerformanceFrequency(out long frequency);

		long freq, start;

		public Stopwatch()
		{
			QueryPerformanceFrequency(out freq);
			QueryPerformanceCounter(out start);
		}

		public double ElapsedTime()
		{
			long current;
			QueryPerformanceCounter(out current);

			return (current - start) / (double)freq;
		}

		public void Reset()
		{
			QueryPerformanceCounter(out start);
		}
	}
}