//  Collision detection test
//
//  Author  Matthew Caryl
//  Created 26.5.97

package Test;

class Bot {
    public int x, y;
    public int r;
    public int dx, dy;
    public boolean collision;
    
    public int ox, oy;
    
    public Bot next, prev;
    public Bucket home;
    
    public boolean outside() {
        return x < home.left || x > home.right || y < home.top || y > home.bottom;
        }
    
    public void add(Bucket H) {
        home = H;
        // add bot beyond dummy head of circular linked list
        next = home.bots.next;
        prev = home.bots;
        home.bots.next.prev = this;
        home.bots.next = this;
        }
    
    public void sub() {
        // remove bot from circular linked list
        next.prev = prev;
        prev.next = next;
        home = null;
        next = null;
        prev = null;
        }
    }

class Bucket {
    public Bucket north;
    public Bucket east;
    public Bucket south;
    public Bucket west;
    
    public int top;
    public int left;
    public int bottom;
    public int right;
    
    public Bot bots;
    }