package cse1030.test2;

import cse1030.drawing.Point2D;



/**
 * An abstract base class for 2D shapes. Each shape has a rectangular
 * bounding box that fits tightly around the shape. The position of
 * the shape is given by the center point of the bounding box.
 * The position of the shape cannot be changed after the shape is
 * created.
 * 
 * @author CSE1030_F13_14
 *
 */
public abstract class Shape {

  /**
   * The width of the bounding box.
   */
	protected double width;
	
	/**
	 * The height of the bounding box.
	 */
	protected double height;
	
	/**
	 * The position of the center point of the bounding box.
	 */
  protected Point2D position;

	
	/**
	 * Constructs a shape having a bounding box of width
	 * and height equal to zero, and center position (0, 0)
	 */
	protected Shape() {
	  this.position = new Point2D();
	  this.width = 0.;
	  this.height = 0.;
	}
	
	
	/**
	 * Constructs a shape having a bounding box with width <code>w</code>,
	 * height <code>h</code>, and center position <code>p</code>.
	 * 
	 * @param w
	 *            the width of the shape's bounding box
	 * @param h
	 *            the height of the shape's bounding box
	 * @param p
	 *            the position of the center of the bounding box
	 * @throws IllegalArgumentException
	 *             if <code>w < 0</code>
	 * @throws IllegalArgumentException
	 *             if <code>h < 0</code>
	 */
	protected Shape(double w, double h, Point2D p) {
		if (w < 0) {
			throw new IllegalArgumentException("width is less than or equal to 0");
		}
		if (h < 0) {
			throw new IllegalArgumentException("height is less than or equal to 0");
		}
		this.width = w;
		this.height = h;
		this.position = new Point2D(p);
	}
	
	/**
	 * Get the position of the center of the bounding box for the shape.
	 * 
	 * @return the position of the center of the bounding box
	 */
	public final Point2D getPosition() {
		return new Point2D(this.position);
	}
	
	/**
	 * Get the width of the bounding box for the shape.
	 * @return the width of the bounding box for the shape
	 * 
	 */
	public final double getWidth() {
		return this.width;
	}
	
	/**
	 * Get the height of the bounding box for the shape.
   * @return the height of the bounding box for the shape
   * 
	 */
	public final double getHeight() {
		return this.height;
	}
	
	/**
	 * Get the area of the shape. <code>Shape</code> provides a default
	 * implementation that returns the area of the shape's bounding
	 * box. Subclasses should override this method to provide the
	 * area of the actual shape.
	 * 
	 * @return the area of the shape
	 */
	public double getArea() {
		return this.height * this.width;
	}
}