Hello. I am making a game that has multiple hostile actors that move toward a player actor. The goal is to maneuver the player in a way that will make the hostiles run into a hole, which will remove the hostile and add to a score. If the hostiles reach the player, the player will die. The problem is that i'm receiving errors after a hostile or player gets removed. The error occurs with the opposite method. So, when player dies, the chasePlayer method throws an error. If a hostile is removed, the killPlayer method throws an error. I'm not sure what functionality to add that will stop these methods from continuing once I reach one of these points. Here is my Hostile code, which is the Super class of my 3 hostiles:
Here is one of my hostile actors, which are subclasses of Hostile:
Here is my Player code:
Here is my World code:
import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
* Write a description of class MyWorld here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Board extends World
{
/**
* Constructor for objects of class MyWorld.
*
*/
public Board()
{
// Create a new world with 600x400 cells with a cell size of 1x1 pixels.
super(1000, 800, 1);
Player tim = new Player();
addObject(tim,400,400);
Red red = new Red(tim);
addObject(red,700,700);
Blue blue = new Blue(tim);
addObject(blue,150,700);
Yellow yellow = new Yellow(tim);
addObject(yellow,150,150);
Hole hole = new Hole();
addObject(hole, 475,400);
}
}
There are two more subclasses of Hostile, which are Yellow and Blue. They have matching code except for the int inside move().
Thanks for any help you can give.
/**
* Write a description of class Hostile here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Hostile extends Actor
{
private Player player;
public Hostile(Player player){
this.player = player;
}
/**
* Act - do whatever the Red wants to do. This method is called whenever
* the 'Act' or 'Run' button gets pressed in the environment.
*/
public void act()
{
}
public void chasePlayer()
{
int deltaX = player.getX() - getX();
int deltaY = player.getY() - getY();
setRotation((int) (180 * Math.atan2(deltaY, deltaX) / Math.PI));
}
public void isAtHole(){
Hole hole = (Hole) getOneIntersectingObject(Hole.class);
if(hole!=null){
Board board = (Board) getWorld();
board.removeObject(this);
}
}
public void killPlayer(){
Player player = (Player) getOneIntersectingObject(Player.class);
if(player!=null){
Board board = (Board) getWorld();
board.removeObject(player);
}
}
}import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
* Write a description of class Red here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Red extends Hostile
{
private Player player;
public Red(Player player){
super(player);
}
/**
* Act - do whatever the Red wants to do. This method is called whenever
* the 'Act' or 'Run' button gets pressed in the environment.
*/
public void act()
{
super.chasePlayer();
move(3);
super.isAtHole();
killPlayer();
}
}import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
/**
* Write a description of class Player here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Player extends Actor
{
public Player(){
}
/**
* Act - do whatever the Player wants to do. This method is called whenever
* the 'Act' or 'Run' button gets pressed in the environment.
*/
public void act()
{
moveKeys();
}
/**
* Check whether a keyboard key has been pressed and react if it has.
*/
private void moveKeys()
{
if (Greenfoot.isKeyDown("up")||Greenfoot.isKeyDown("W"))
{
setLocation(getX(), getY()-8);
}
if (Greenfoot.isKeyDown("down")||Greenfoot.isKeyDown("S"))
{
setLocation(getX(), getY()+8);
}
if (Greenfoot.isKeyDown("right")||Greenfoot.isKeyDown("D"))
{
setLocation(getX()+6, getY());
}
if (Greenfoot.isKeyDown("left")||Greenfoot.isKeyDown("A"))
{
setLocation(getX()-6, getY());
}
}
}
