[UDMF] LineDef Flags to Show as Over/Under on the AutoMap

[NeuralStunner]

Similar to the Secret and Never Show flags, I would like to be able to flag lines as floor/ceiling differences. This has a few different uses:

- For 3D floors, one could simply flag the outer lines of the destination sector, rather than needing to make a 1 unit floor or ceiling difference in order to show things like bridges or tables on the map.
- It could be used to draw static arrows or other marks on the map, without needing make them dark like impassable lines.
- It could be used to mark the borders between different floors that are the same height, where usually the lines between would be invisible.

I imagine precedence would be:
1. Never Show
2. Secret
3. Floor Difference
4. Ceiling Difference

(For 3 and 4, I'm going by in-game behavior: Lines with both floor and ceiling height changes show the color for floor difference.)

[Xaser]

This sounds really damn useful, especially with 3D floors.

[Gez]

I've been wanting to add a new color for 3D floor boundaries for a while now...

[randi]

So why don't you do that, then?

[Gez]

Maybe because I'm doing other stuff.

[Gez]

I've been wanting to add a new color for 3D floor boundaries for a while now...

For what it's worth, this is now in the 3dfloors2 branch.

[Graf Zahl]

I don't see any flags there.