import greenfoot.*; 

public class FlappyBird extends Actor
{
    double dy = 0 ;
    double g = 1.3 ;
    double BOOST_SPEED = -15 ;
    public void act() 
    {
        setLocation( getX(),(int)(getY() + dy));
        // jika tombol atas ditekan
        if (Greenfoot.isKeyDown("up") == true) {
            dy = BOOST_SPEED;
        }
        // jika flappy jatuh maka game over
        if (getY() > getWorld().getHeight()) {
            System.out.println("Game Over") ;
            Greenfoot.stop();
        }
        dy= dy + g ;
    }    
}