SS:EE Mouse deceleration (acceleration)? [SOLVED]

[68a935027a6dbWild Penguin]

Hi,

There's this minor annoyance in System Shock: Enhanced edition (the new-ish source port). I believe others have it too - I can find some threads which are describing a similar problem but no solutions (at gog.com and steam forums).

The thing is, there is weird mouse acceleration, or in this case more precisely deceleration going on: the game filters out all very slow mouse movements.

This makes precise movements difficult when in freelook mode or small cursor movements difficult while in interaction (non-freelook) mode. I get best results if I set mouse smoothing "on" and set mouse sensitivity to lower and my mouse DPI/sensitivity (outside SS:EE) to a very high value, to work around the issue; this makes the non-interactive part of the speed-curve smaller, and smooths out movement if using the mouse near the threshold / limit, but does not remove it. In other words: that is a workaround, and certainly not optimal!

I believe this is a limitation of the engine (being a DOS game with originally no mouselook), but it could certainly be some kind of bug on my system. Judging from other threads, I believe it is the former ... I believe people just turn on smoothing and live with the issue or don't even notice it, if they've used to mouse acceleration in games.

One thing that needs to be mentioned at this point, is that I'm running on wine / Linux. Tried with a fresh wineprefix and WINEARCH=win32, just to make sure it is not some weird bug caused by a stale config, but the behavior seems same.

Any ideas how to improve this? Similar experiences?

[68a935027a900Kolya]

I don't know about this issue, but I think setting software mouse sensitivity low and hardware sensitivity high is generally a good idea for precise mouse movement.
Just an idea: Have you tried playing around with the system mouse settings (if that exists in wine). Windows screenshot for reference. The setting "Enhance pointer precision" accelerates the cursor across large distances and might play a role in this.

[2019-01-22 21_37_14-Window.png expired]

[68a935027aba2Wild Penguin]

Hi Kolya,

There are of course mouse sensitivity settings on the host OS (Linux; probably via xinput, I use Plasma which has nice GUI for acceleration). Wine does not have any input related settings of it's own. It is kind of a slave in this regards, and has few settings related to input, and those would not make much sense; I believe it's libraries just receives mouse cursor / mouse movement data, clicks etc..

I'm certain it is just SS:EE that has this behavior. No other application or game (in Wine or native) has this. I've played some games which have (well known) forced acceleration issues (both wine and native), but that is usually experienced when the mouse speed is high(er). None have this severe "deceleration / filtering at slow speed" issue, and I've never heard about that. That's why I find this a bit odd.

I noticed I did have some acceleration enabled at the OS level (I  though I had disabled it). I disabled it (it's better that way in all FPSes, only DEs might benefit from acceleration and it's even questionable then IMO). That does make it even more smoother in SS:EE and it is very much playable now. I can forget the issue while playing, so I'm kind of cool it with now (but it is still there if I go "looking for it").

Don't you have this issue? It is really easy to reproduce: move mouse slowly (very slowly, say 1cm every 5 seconds, even slower if you can) and the cursor should move very little if at all (even if you continue indefinitely). Move the same amount faster, and the cursor begins moving properly (or Goggles ... is it Goggles? ... is turning - doesn't matter which mode you are in).

By varying the speed, you will find a threshold speed, when the mouse will be "jerky". It is difficult to reproduce if your settings (sensitivity, smoothing) already work around the issue, since the "dead zone of speed" will be very small then (but: there should be no dead zone!).  The sensitivity settings in SS:EE seem to affect the mouse input after this threshold is reached, AFAICT. If you can not reproduce this, but want to make sure you don't have it, reduce sensitivity in Windows temporarily. If you can not reproduce this - well, then, it must be just me / wine then!

[68a935027b078Wild Penguin]

Ok, helping myself, I figured out how to get good mouse responsiveness. I'll describe the solution here in case someone is in the same boat. The sensitivity works very oddly on my system and it is difficult to describe but I'll try EDIT: in this post I mean the settings in SS:EE only. System settings work as expected.

EDIT: Nope! Stroke trough most of my post. Seems that the "imaginary box" where mouse cursor is semi-confined is there at every startup, is removed randomly and comes back randomly. SS:EE sensitivity settings have nothing to do with it. It is probably some kind of weird focus issue. ALT+TAB:ing does not fix it, except sometimes (?). Very weird and inconsistent indeed - and could definitely be a wine bug! If I notice what triggers it and how to fix it, I will update this thread. Luckily, if it starts behaving correctly, seems it will stay that way until the game is restarted (which is good).

[FINAL EDIT]
Ok, it is a focus issue. Possibly Plasma/KDE misbehaving but with just this SS:EE (never had anything like this before). The good thing I noticed how to consistently get the mouse to behave; press and hold TABALT while ALT+TAB:n (don't release TABALT); this causes a Plasma window list being displayed (even if SS:EE was the only window, the list is still displayed). Hold TABALT and cycle back to SS:EE (and then release TABALT). Click once - and now mouse behaves correctly!

If I raise the game window (or just start it), mouse is kind of captured into the game, but in this "movable box". ALT+TAB:n away (or using another virtual desktop, which I use a lot) and coming back will not fix it - except if done in the above manner, i.e. kind of ALT-TAB:n but never giving focus to another application.

I still feel that this "movable box" is such a peculiar symptom, that it mandates an explanatory cat video to demonstrate the effect to be posted. https://www.reddit.com/r/aww/comments/aii4d2/nyoom/

This one also demonstrates being freed from the "movable box": https://www.youtube.com/watch?v=RTwlE7xgyDk
[/FINAL EDIT]


It seems there are two phaces of sensitivity. If sensitivity value is in the tens (not sure about the limit) there is only a single phase. But if it is increased enough (>50 or something) this "tho-phase" -phenomen comes into play. There is a very small range of movement which will work for small movements only (a small box around whatever is the the center of the box). After reaching the limit of this imaginary box, the mouse stops ... unless it is moved fast enough, which will move this "imaginary box".

Also,  the actual sensitivity value is not linear; it increases until this tipping point (not sure where it is actually) is reached, and this is where this "imaginary box" comes into play. This also causes an experienced overall decrease in sensitivity, although the value has been increased.

It is possible this is some kind of calculation error in the code (possibly caused by wine) which has to do with mouse acceleration - or the game / sensitivity is just buggy.

TL;DR: Sensitivity setting is buggy on my system. In case you have the same problem, set sensitivity to a very low value in SS:EE (say, 1 or 5) and then slowly (in 1-2 increments) increase it until it behaves.  There are two phases in the values, where the mouse input behaves totally differently!