import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
 * A bullet to be shot at asteroids.
 * 
 * The Shot moves to the top of the screen and then expires. If it hits an asteroid
 * on the way, it destroys the asteroid, and then expires immediately.
 */
public class Shot  extends Actor
{
    private SpaceShip myShip;
    private static final int damage = 16;

 
    public Shot(SpaceShip myShip)
    {
        this.myShip = myShip;
    }

    /**
     * Act - do whatever the Shot wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        int ypos = getY();
        if (ypos > 0) {
            ypos = ypos - 1;
            setLocation(getX(), ypos);
            Actor rock = getOneIntersectingObject(Asteroid.class);
            if (rock != null) {
                // We've hit an asteroid!
                hitAnAsteroid();
                World myWorld = getWorld();
                getWorld().removeObject(rock);
                ScrollWorld sw = (ScrollWorld)myWorld;
                Counter counter = sw.getCounter();
                counter.addScore();
                getWorld().removeObject(this);
            }
        }
        else {
            // I reached the top of the screen
            getWorld().removeObject(this);
        }
    }
}