Thing sprites with unintended vertical rendering shift

[printz]

I'm mentioning as an example the Strife WaterDrip actors, doomednum 53, who hang from ceiling. Under GZDoom they're shifted upwards, so I can only see their tips protruding from inside the ceiling, which look like lousy 2x2 squares instead of actual drops.

[Gez]

There's no sprite clipping adjustment for things that are on the ceiling.

I've made some quick copypasta of the floor clipping adjustment code to make it adjust the ceiling clipping as well, and this actor was then displayed in its full glory. This is based on this patch, though. I'm posting it more for reference than for direct inclusion because I'm not sure I handled the 3D floor case correctly.

[Graf Zahl]

The reason I never handled this case is that it's much more likely to cause problems than the floor case.

[Gez]

What kind of problems?

[Graf Zahl]

Sprites jumping up and down, badly positioned sprites and such.

[Gez]

I imagine this would mostly be a potential concern for moving actors. So maybe these problems could be avoided by a velocity check?