public void step(float delta) {
		camera.step(delta, girl.getPosition(), 0.05f);
		getWorld().step(delta / 1000, 8, 3);
		girl.step();
		if (Keyboard.isKeyDown(Keyboard.KEY_D)) {
			girl.walkRight();
		}

		if (Keyboard.isKeyDown(Keyboard.KEY_A)) {
			girl.walkLeft();
		}

		if ((Keyboard.isKeyDown(Keyboard.KEY_SPACE) || Keyboard.isKeyDown(Keyboard.KEY_W)) && !girl.isInAir()) {
			girl.jump();
		}
	}