bullet help

The spaceship class is where you are creating and adding a new bullet object into the world; you should probably set its rotation there also. Moving only two pixels per act will allow only about 16 different angles to move in. This would make an average of 22 to 23 degrees between adjacent angles. If you do not wish to increase the speed, you might consider using double values to track the location of the bullet for smoother movement.

after creating the thing to shoot Bullet b = new Bullet(); b.setRotation(angle you want);

The angle you want is the angle of the Spaceship (if your spaceship with a rotation of zero faces right). If you are creating the bullet in the class of the spaceship, you get the rotation of the spaceship with the 'getRotation' method.

if the object creating the bullet is the space ship you gota make a method in ur spaceShip calss like public void fireBullet() { Bullet b = new Bullet();//makes the bullet b.setRotation(getRotation());//sets the rotation of the bullet to be the same as the ship's getWorld().addObject(b, getX(), getY()); }

I have another question I used atWorldEdge in my bullet class so it would disappear when it hit the world edge. but this comes up java.lang.IllegalStateException: Actor not in world. An attempt was made to use the actor's location while it is not in the world. Either it has not yet been inserted, or it has been removed. at greenfoot.Actor.failIfNotInWorld(Actor.java:663) at greenfoot.Actor.getX(Actor.java:157) at Bullet.atWorldEdge(Bullet.java:53) at Bullet.act(Bullet.java:20) at greenfoot.core.Simulation.ac

that means you are trying to do something with the bullet after it has been removed. just put return; after removing the bullet and it should be fine; if that does not work then put a if statement in front of all ur code to check to see if bullet is in world like this act() { if(getWorld() != null)//is in a world { * ur code } }

here is all of the code import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo) /** * Write a description of class Bullet here. * * @author (your name) * @version (a version number or a date) */ public class Bullet extends Actor { /** * Act - do whatever the Bullet wants to do. This method is called whenever * the 'Act' or 'Run' button gets pressed in the environment. */ public void act() { move(5); if(getWorld() != null) { } shotasteriod(); if ( atWorldEdge() ) { getWorld().removeObject(this); } } /** * destroy's asteroid and bullet. */ public void shotasteriod() { Actor asteroid = getOneObjectAtOffset(2, 2, asteroid.class); if(asteroid != null) { Greenfoot.playSound("Explosion.mp3"); getWorld().removeObject(asteroid); getWorld().removeObject(this); } } public boolean atWorldEdge() { if(getX() < 10 || getX() > getWorld().getWidth() - 10) return true; if(getY() < 10 || getY() > getWorld().getHeight() - 10) return true; else return false; } }

public void act() { move(5); shotasteriod(); if ( atWorldEdge() ) { getWorld().removeObject(this); return; } } you also don't need the if(getWorld() != null) thing in this case