Lecture Notes on 15 April 2013

class Point
{
  // Attributes
  public double x;
  public double y;

  // Default Constructor
  public Point ()
  {
    x = 0.0;
    y = 0.0;
  }

  // Non-default Constructor
  public Point (double x, double y)
  {
    this.x = x;
    this.y = y;
  }

  // Other methods
  public double dist (Point p)
  {
    return Math.hypot (this.x - p.x, this.y - p.y);
  }

  public String toString ()
  {
    String s = "(" + x + ", " + y + ")";
    return s;
  }
}

class Circle
{
  // Attributes
  private double radius;
  private Point center;

  // Default constructor
  public Circle ()
  {
    radius = 1.0;
    center = new Point ();
  }

  // Non-default constructor
  public Circle (double radius, double x, double y)
  {
    this.radius = radius;
    this.center = new Point (x, y);
  }

  // Accessors
  public double getRadius ()
  {
    return this.radius;
  }

  public Point getCenter ()
  {
    return this.center;
  }

  // Mutators
  public void setRadius (double radius)
  {
    this.radius = radius;
  }

  public void setCenter (double x, double y)
  {
    this.center.x = x;
    this.center.y = y;
    // this.center = new Point (x, y);
  }

  // Other methods
  public double circumference ()
  {
    return 2.0 * Math.PI * radius;
  }

  public double area ()
  {
    return Math.PI * radius * radius;
  }

  public boolean isInside (Circle c)
  {
    return (this.radius > (this.center.dist (c.getCenter()) + c.getRadius()));
  }

  public boolean doesOverlap (Circle c)
  {
    return (this.center.dist (c.getCenter()) <= (this.radius + c.getRadius()));
  }

  public String toString ()
  {
    String s = "Radius: " + radius + "  Center: " + center;
    return s;
  }
}
public class Geometry
{
  public static void main (String[] args)
  {
    // Create a default Point object
    Point pointA = new Point ();
    System.out.println (pointA);

    // Create a non-default Point object
    Point pointB = new Point (3.0, 4.0);
    System.out.println (pointB);

    // Get distance between the two points
    System.out.println (pointA.dist(pointB));

    // Create Circle objects
    Circle circleA = new Circle ();  // default circle
    System.out.println (circleA);

    Circle circleB = new Circle (2.4, 1, 3);  // non default circle
    System.out.println (circleB);

    System.out.println (circleA.circumference());
    System.out.println (circleB.area());

    if (circleA.doesOverlap (circleB))
      System.out.println ("CircleA overlaps CircleB");
    else
      System.out.println ("CircleA does not overlaps CircleB");
  }
}