Mirrors don't work after indexbuffer merge

[Marisa the Magician]

Just loaded Kinsie's test map and turned around. The mirror isn't rendering anymore in OpenGL.

[Xane123]

I'm going to assume this is also what broke reflective surfaces in my game as well! Now instead of reflecting, the surface just turns transparent and you can see the sky and lower sectors through it!

Broken mirror and reflective plane rendering

(Also, broken mirror visible in screenshot. Hope this is fixed sometime.)

[_mental_]

Fixed in 0187b0a.

[Xane123]

Thanks, _mental_. It's strange how updates to GZDoom break random things but I guess that's why they're development builds.

[Rachael]

No, it's not strange at all.

The part of the code that this affects was completely wiped out and rewritten. Bugs are going to happen in such a scenario because there's no possible way anyone (not even Graf, who likely knows more than anyone else about the code base right now) can account for every possible use scenario in one go.

Don't forget: GZDoom is a very complex piece of software.

[Graf Zahl]

Even so, I think for mirrors the fix needs to be reviewed. It cannot use the map section info of the current viewpoint. It has to use the map section of the original viewpoint. A mirrored viewpoint can lie in an entirely different section and still produce empty content as a result.

Will check when I get back home later.

[_mental_]

Yes, you are right. To make it work the same as before UpdateCurrentMapSection() calls need to be moved at the begging of DrawContents() functions I think, here and here.

[Graf Zahl]

For a plane mirror it's not really relevant because the x/y will be the same. Only for a wall mirror this is an issue.

[_mental_]

OK, I hope it's finally fixed in f06ee10.