In a 2D platformer, I'd like to implement a ladder. I have collision working between the player and ground tiles. Now I would like to be able to detect when the player walks through a ladder tile (which can be one of three tile indices). When the player is overlapping a ladder and up is being pressed, the climbing state would be set.

Ideally, I'd like to get a callback when this happens. It seems that the `overlap` method from Arcade physics is not available in P2. What is there instead to implement overlap detection?