package rebelsky.twodim;

import java.io.PrintWriter;

/**
 * A vector in two space.
 *
 * @author AUTHOR
 * @version VERSION
 */
public class TwoDimVector 
{

// +--------+-------------------------------------------------------
// | Fields |
// +--------+

	double xcoord;
	double ycoord;

// +--------------+-------------------------------------------------
// | Constructors |
// +--------------+

	public TwoDimVector(double x, double y)
	{
		this.xcoord = x;
		this.ycoord = y;
	} // TwoDimVector(double,double)
	
// +----------+-----------------------------------------------------
// | Mutators |
// +----------+


// +-----------+----------------------------------------------------
// | Observers |
// +-----------+

	public double dotProduct(TwoDimVector other)
	{
		return ((this.xcoord*other.xcoord) + (this.ycoord*other.ycoord));
	} // dotProduct

	public double getX()
	{
		return this.xcoord;
	} // getX()
	
	public double getY()
	{
		return this.ycoord;
	} // getY()
	
	public double getAngle()
	{
		return Math.asin(this.ycoord/this.getDistanceFromOrigin());
		// return Math.atan(this.ycoord/this.xcoord);
	} // getAngle()

	public double getDistanceFromOrigin()
	{
		return Math.sqrt(this.xcoord*this.xcoord + this.ycoord*this.ycoord);
	} // getDistanceFromOrigin()
	
	public boolean isLessThan(TwoDimVector other)
	{
		return this.getDistanceFromOrigin() < other.getDistanceFromOrigin();
	} // isLessThan(TwoDimVector)
	
	/**
	 * Return a new vector that is a scaled version of the current vector.
	 */
	public TwoDimVector stretch(double factor)
	{
		return new TwoDimVector(this.xcoord*factor, this.ycoord*factor);
		// Multiply the x coordinate by factor
		// Multiply the y coordinate by factor
		// Shove the two things into a vector and return it
	} // stretch(double)

	public TwoDimVector unitVector()
	{
		double radius = this.getDistanceFromOrigin();
		TwoDimVector result = new TwoDimVector(this.xcoord/radius, this.ycoord/radius);
		return result;
	} // unitVector()
	
	public String toString()
	{
		return "(" + Double.toString(this.xcoord) + "," + Double.toString(this.ycoord) + ")";
	} // toString()
	
	public void printYourself(PrintWriter pen)
	{
		pen.println("xcoordinate: " + this.getX());
		pen.println("ycoordinate: " + this.getY());
		pen.println("theta: " + this.getAngle());
		pen.println("radius: " + this.getDistanceFromOrigin());
	}
} // class TwoDimVector