3D floor awareness for CheckSwitchRange

[Gez]

Pull request
Inspiration

In a nutshell: if you put a switch on a 3D floor's side, you'd like it to work like a switch on a regular wall. You can do that by having a switch texture on the upper or lower texture of the holding sector, and using the "use upper/lower texture" flag, as appropriate, on your Sector_Set3dFloor control line.

However, if you also want to have the check switch range effect, you're out of luck, since it'll only look if the player can reach the actual upper or lower texture, not the texture projected on a 3D floor.

Attached is a test map. It allows to verify that it actually works (check the central switch platform for a upper switch effect, and the small green switch 3D floor for the lower switch effect) and that it didn't seem to break other check switch range constructions (there's a small green switch 3D mid texture set that mirrors the lower switch effect, a switch on a middle texture that you can ride a perpetual platform to activate, and a switch on a lower texture below a 3D floor).

[Eevee]

Oh thank goodness. I ran into this recently myself and figured CSR was to blame. Heartily support merging this.

I feel like ZDoom ought to also handle the case where the switch texture actually comes from the control line, but I can't imagine that's a very common setup.