public void update() {
		input.update();
		if (input != null) {
			if (input.up) {screen.changeOffset(0, -1);
			System.out.println("up");}
			if (input.down) {screen.changeOffset(0, 1);
			System.out.println("down");}
			if (input.left) {screen.changeOffset(-1, 0);
			System.out.println("left");}
			if (input.right) {screen.changeOffset(1, 0);
			System.out.println("right");}
		}
	}