ZDoom

So there are maps where you can jump into say a high shelf of a bookshelf (for example) where you can only fit into if you're crouched, requiring you to be in crouch mode in mid air? In that case perhaps at least not make flying slower when crouched, adding a onground check?

https://github.com/coelckers/gzdoom/blo ... player.txt
in virtual void MovePlayer ()

// When crouching, speed and bobbing have to be reduced
if (CanCrouch() && player.crouchfactor != 1 && player.onground)

I have thought about this, but this cannot be done because +crouch reduces your movement speed no matter where you are or your flying state, and crouch needs to be enabled in the air anyhow. As it is you will just have to use +moveup/down in order to move up or down. I'll leave this open for a day just in case Graf has anything different to say about this, but I don't see any likelihood this is going to change. I'd prefer to see it done differently too but the way we have it now is what we have.

Currently I'm using aliases to combine jump/upmove and down/crouch, to avoid having to deal with multiple buttons, or switching over button function

alias +upjump "+moveup;+jump"
alias -upjump "-moveup;-jump"

alias +downcrouch "+movedown;+crouch"
alias -downcrouch "-movedown;-crouch"

bind a +upjump
bind z +downcrouch

I do a similar alias setup in Hexen 2, which uses the Quake 1 engine.

It would be nice to have moveup and movedown function like in Quake 2 and Quake 3.
In those games:
-if you're on the ground it interprets moveup as jump, otherwise as moveup
-if you're on the ground it interprets movedown as crouch, otherwise as movedown

Currently in GZDoom with my alias system, while flying forward
-and moving up I'm not slowed, as I'm not in crouch mode
-and moving down I'm slowed, as it is in crouch mode

This could be fixed with an onground check for crouch move, but overloading the moveup and movedown functions might be even better.
(jumping while flying doesn't make much since, crouching while flying, maybe, like scrunching your body for a lower drag coefficient or smaller target size)