// CSE 142, Autumn 2010, Marty Stepp
// This class defines a new type of objects named Point.
// Each Point object represents one (x, y) location.
// Today's version adds a constructor and encapsulation,
// which means that the fields are private so the client can't mess with them.

import java.awt.*;  // for Graphics

public class Point {
    private int x;    // each Point object has its own copy
    private int y;    // of each of these variables  (fields)
    
    // Constructs a point at the given x/y coordinates.
    // A constructor gets called when client asks for a 'new' object
    // A constructor's duty is to initialize the state of that new object.
    public Point(int initialX, int initialY) {
        x = initialX;
        y = initialY;
    }
    
    // Constructs a point at the origin, (0, 0).
    public Point() {
        // don't need to set them to 0 because they already start out as 0
        // x = 0;
        // y = 0;
    }
    
    // Returns the x-coordinate of the point.
    public int getX() {
        return x;
    }
    
    // Returns the x-coordinate of the point.
    public int getY() {
        return y;    
    }
    
    // Shifts the position of the point by the given x/y amounts.
    public void translate(int dx, int dy) {
        x += dx;
        y += dy;
    }
    
    // Returns the distance between this point and the origin, (0, 0).
    // Example call: p1.distanceFromOrigin()
    public double distanceFromOrigin() {
        return Math.sqrt(x*x + y*y);
    }
    
    // Returns the distance between this point and the given other point.
    // Example call: p1.distance(p2)
    // We pass just 1 point parameter, not 2, because the other point
    //  is "this" point, the implicit parameter, the object you called the method on.
    public double distance(Point other) {
        int dx = other.x - x;
        int dy = other.y - y;
        return Math.sqrt(dx*dx + dy*dy);
    }
    
    // EACH Point object gets its own copy of the method,
    // the method knows which object you called it on,
    // and it can directly access the data (fields) in that object by name.
    // This method draws this point using the given graphics pen.
    public void draw(Graphics g) {
        g.fillOval(x, y, 3, 3);
        g.drawString("(" + x + ", " + y + ")", x, y);
    }

    // This method returns a String representation of this point,
    // such as "(3, -4)", so that Points can be printed.
    public String toString() {
        return "(" + x + ", " + y + ")";
    }
}