Problem with mouse firing. (probably math related?)

Newbie & Debugging Questions
#1

In the game i am making i have run into a problem when it comes to using the mouse to fire bullets.
The bullets go in a completely different direction then what i want them to do.
You have probably had people with this problem several times, i have looked trough 3 of the posts on JG, but cant find an answer that helps me in there.

I am doing this in LibGDX.

These are the related methods;

Part of the InputProcessor in Player.java. (mouseMoved because i dont want to click at the moment, for testing.)


	public boolean mouseMoved(int screenX, int screenY) {
		this.mouseX = screenX - position.x / 2;
		this.mouseY = screenY - position.y / 2;
		this.dir = Math.atan2(mouseY, mouseX);	
		shoot();
		return false;
	}

Shoot method in Player.java


public void shoot() {
	bullets.add(new Bullet(new Vector2(position.x, position.y), 350, dir));
	}

Constructor in Bullet.java


	double newX, newY;

	public Bullet(Vector2 position, int SPEED, double dir) {
		this.position = new Vector2(position.x, position.y);
		Math.cos(dir);
		this.newX = SPEED * Math.cos(dir);
		this.newY = SPEED * Math.sin(dir);
		}

Update method in Bullet.java


public void update() {
		position.x += newX * Gdx.graphics.getDeltaTime();
		position.y += newY * Gdx.graphics.getDeltaTime();
	}

I am copying TheChernos way of doing it, and it works when in the game i have created in his tutorial.
These are the related stuff in that code. The difference i can see if where deltatime is added.


private void updateShooting() {
		if (Mouse.getB() == 1) {
			double dx = Mouse.getX() - Game.getWindowWidth() / 2;
			double dy = Mouse.getY() - Game.getWindowHeight() / 2; 
			double dir = Math.atan2(dy, dx);
			shoot(x, y, dir);
			}
	}

/////////////

public Projectile(int x, int y, double dir) {
		xOrigin = x;
		yOrigin = y;
		angle = dir;
		this.x = x;
		this.y = y;
		Math.cos(angle);		
		nx = speed * Math.cos(angle);
		ny = speed * Math.sin(angle);
	}

//////////
public void move() {
		x += nx;
		y += ny;
	}

I also tried looking at ForeignGuyMikes Asteroids tutorial, but couldnt get that to work either.