this map/mod/wad requires opengl renderer

[drfrag]

Then add the CVAR_NOSET flag instead of a warning (actually there would be no need for setting it manually).

[Graf Zahl]

What about setting vid_renderer to 1 for vid_rendermode 4 and 0 for the rest of them? At the same time allowing it to be set by users, it would be properly updated when rendermode changes again.

No, I absolutely DO NOT WANT this!

Me neither. It's too bad that such misguided checks can only be dealt with after the damage has been done.

Then consider all chances of this problem being getting actually solved properly finished off, at least for me.

Impossible. We can set vid_renderer to 1 by default and deal with those checking for 0 or we can set it to 0 by default and deal with those checking for 1.
There's no other alternatives here. And think we have to preemptively block vid_rendermode entirely for both ACS and ZScript because it poses the same problem if some users just cannot act responsibly.

[Rachael]

Then add the CVAR_NOSET flag instead of a warning (actually there would be no need for setting it manually).

I disagree here, too. A warning is a better solution.

[Rachael]

And think we have to preemptively block vid_rendermode entirely for both ACS and ZScript because it poses the same problem if some users just cannot act responsibly.

I agree with this. I just never knew how to implement it, myself, but we should consider doing a CVAR_NOSCRIPT flag for CVars that strictly deal with user preference, which makes it impossible for scripts to access it.

Things like SSAO, MSAA, FXAA, dither, etc.

[Korell]

This was mentioned on my ModDB page for my fixed version of Pirate Doom! I wasn't able to replicate the issue as my ini file was relatively old and so had the vid_renderer=1 set within it (under the GlobalSettings.Unknown section) so the mod found the expected value even though it was doing nothing for GZDoom, and so I didn't know what the issue was for the users. Thanks to this thread I've now been able to see what the issue was and replicate it, and I'm now about to upload a new version to ModDB as the check was taking place in just two maps. It was literally checking the value of vid_renderer and if it wasn't set to 1 then it was showing some messages on screen on the first map advising the user to change to OpenGL, and then on the second map it would give some more messages before killing the player - very annoying.

[Graf Zahl]

Added the fake CVAR to silence these mods. Making it foolproof is sadly not doable.