Ball.java

package PongGame;

import java.awt.Color;
import java.awt.Graphics;

public class Ball {
	
	public static final int SIZE = 16;
	
	private int x, y;
	private int xVel, yVel;
	private int speed = 5;
	
	public Ball() {
		
		reset();
		
	}

	private void reset() {
		
		x = Game.WIDTH/2 - SIZE/2;
		y = Game.HEIGHT/2 - SIZE/2;
		
		xVel = Game.sign(Math.random()*2 -1);
		yVel = Game.sign(Math.random()*2 -1);
		
	}
	
	public void changeXDir() {
		xVel *= -1;
	}
	
	public void changeYDir() {
		yVel *= -1;
	}

	public void draw(Graphics g) {
		
		g.setColor(Color.white);
		g.fillOval(x, y, SIZE, SIZE);
		
	}

	public void update(Paddle paddle1, Paddle paddle2) {
		// ball movement
		x += xVel * speed;
		y += yVel * speed;
		
		// for collisions with upper and lower walls
		if(y >= Game.HEIGHT - SIZE || y<= 0) {
			changeYDir();
		}
		
		// for paddle miss
		if(x >= Game.WIDTH - SIZE) {
			paddle1.addPoint();
			reset();
		}
		if(x <= 0) {
			paddle2.addPoint();
			reset();
		}
	}

	public int getX() {
		return x;
	}

	public int getY() {
		return y;
	}

}