GZDoom compatibility question

Wed Jul 07, 2021 7:15 am

Hello everyone.

I've recently been messing around with some compatibility settings in GZDoom, to see what worked best for me (infinitely tall monsters was always something that pissed me off).
I know GZDoom has different comp. modes like Default, Doom (strict), Boom, etc...

My question is, if I leave it on Default for convenience, would it be able to break some maps?
For example, would playing DOOM.WAD on Default cause some maps to break?
If yes, could someone give a known example of a map that could break if set to Default compat.?

Re: GZDoom compatibility question

Wed Jul 07, 2021 8:54 am

Generally, nothing should be outright broken. GZDoom is smart enough to have a database of known "broken" maps internally, to which it will automatically set the specific compat option to make them work correctly.

Re: GZDoom compatibility question

Wed Jul 07, 2021 9:18 am

I was reading the ZDoom wiki and I came across this:
"1 - Doom; Enables a set of options that should allow nearly all maps made for vanilla Doom to work in ZDoom:"

From my understanding, (or maybe just my level of english), makes it seem like if you don't set it correctly, some maps would not work, that's why I was asking if leaving the default compat. would break something.

Re: GZDoom compatibility question

Wed Jul 07, 2021 10:17 am

It'd frankly be safer to leave it at Default until you see something that is very obviously broken. Ideally, there should never be a reason to mess with the compat flags yourself.

Re: GZDoom compatibility question

Wed Jul 07, 2021 11:50 am

The only reason why maps would not work in GZDoom is if they exploit some of Doom's weird bugs and when those are fixed the map breaks.

But that's where the built-in database of broken maps comes in handy to automagically resolve the problems.

If you set the option to Doom, the risk is high that when you later play a map that's not for vanilla Doom, you'll break something because the map was designed for Boom or ZDoom or whatever else and it actually expected some of the slight behavior changes from vanilla. For example, a very common issue is people not being able to open doors, because there's another line in front of the door with a special action on it, and in vanilla Doom this blocks the "use" attempt because it stops at the first line with a special action, even if it's not a <use> action.

See, the deal is that the database is there to set the options that are needed. But it doesn't unset the options that are unneeded. It would be far too much work to check every map for options that specifically need to be unset, especially given that new options may appear from time to time if needed.

Re: GZDoom compatibility question

Wed Jul 07, 2021 12:05 pm

Gez wrote:The only reason why maps would not work in GZDoom is if they exploit some of Doom's weird bugs and when those are fixed the map breaks.

But that's where the built-in database of broken maps comes in handy to automagically resolve the problems.

If you set the option to Doom, the risk is high that when you later play a map that's not for vanilla Doom, you'll break something because the map was designed for Boom or ZDoom or whatever else and it actually expected some of the slight behavior changes from vanilla. For example, a very common issue is people not being able to open doors, because there's another line in front of the door with a special action on it, and in vanilla Doom this blocks the "use" attempt because it stops at the first line with a special action, even if it's not a <use> action.

See, the deal is that the database is there to set the options that are needed. But it doesn't unset the options that are unneeded. It would be far too much work to check every map for options that specifically need to be unset, especially given that new options may appear from time to time if needed.


Okay, this makes sense. I'll just leave the compatibility mode Default then.
Thanks everyone for the information.