/*
 *
 * Thing
 *
 */


public class Thing
	{
     	// internal parameters to hold state
	// idea is that each Thing has a position in the 2D plane
	
	private double m_dXPos, m_dYPos;

	//	methods for creating an instance
	Thing ()
	{ this(0, 0); // invoke more general constructor
	}

	Thing (double dxpos, double dypos)
	{ // setup state variables
		m_dXPos = dxpos;
		m_dYPos = dypos;
	}

        // methods for allow other methods to access values of variables

	public double XPos ()
	{return m_dXPos;}

	public double YPos ()
	{return m_dYPos;}


	// methods to update parameters
        public void ChangeXPos (double delta)
	{ m_dXPos = m_dXPos + delta;}


    	public void ChangeYPos (double delta)
	{ m_dYPos = m_dYPos + delta;}

}