public void update(GameContainer gc, int delta) throws SlickException {
		quadtree.clear();
		for (Shape shape : collisionObjects)
			quadtree.insert(shape);

		player.update(gc, delta);
		viewport.update(player);

		List<Shape> collidableShapes = Lists.newArrayList();
		for (int i = 0; i < collisionObjects.size(); i++) {
			collidableShapes.clear();
			quadtree.retrieve(collidableShapes, collisionObjects.get(i));

			for (int k = 0; k < collidableShapes.size(); k++) {
				if (player.getCollisionShape().intersects(collidableShapes.get(k)) && !player.getCollisionShape().equals(collidableShapes.get(k))) {
					System.out.println("PLAYER COLLISION!");
				}
			}
		}
	}