I want to be able to do what you see in the image, but with a single wall. The player should be able to walk on either side of the same object. That is, the same wall is below the hero when I go down from it, and it's above the hero if I come from above it.
It's like two depths in the same wall, so its not just a matter of drawing it before or after. I could cut the object in two, but that would be the easy (and maybe computationally expensive) solution. How should I do this?