[CHANGE] ZDoom Doom in Hexen Format ACS Floor Scrollers are Additive

[thefatwilly]

Describe the bug Oda treats ACS controlled scroller variables as additive, causing players to speed up or slowdown dramatically if traveling on the seam of a scrolling sector.

Build that the bug occurred in 10.1 online 10.2 RC3 offline

To Reproduce Wad provided odascrollertest.zip

Also possible online, see Wanderlust (map29) in WDL2022.wad

Expected behavior Scroller variables are a flat speed increase/decrease in standard zdoom ports.

[rakohus]

Given conversations we had on discord, I'm not sure this is technically a "bug" as it seems to be the vanilla hexen behavior. Whether or not we want to adopt the modern ZDoom behavior, which seems to mitigate this behavior, is probably the question for discussion here

[thefatwilly]

then perhaps this is better off as a toggle cvar so servers can customize which compatibility to adhere to? As Oda does not have full hexen support in the latest stable, players from other doom ports will expect this behavior to act with what they are familiar with.

[bcahue]

Maybe disable the carry adjustment and player-in-sector bonus (for hexen specials) when co_zdoomphys 1?

[bcahue]

The alternative is to match ZDaemon's behavior, where the Hexen specials apply the in-sector speed bonus, but ACS scripts do not.