Messages make oolite jump/lose time/something like that

[Diziet Sma]

Can one of the Linux players please check and report back so that we can determine whether it is a problem of the eSpeak integration in Oolite in general or something Windows specific?

Very low-spec (CPU-wise) 10 year old Linux system here.

Any number of events (a missile launch, a ship appearing on scanner, etc) in Oolite can, but doesn't always, cause very momentary (and I do stress momentary) glitching in my game. Akin, perhaps, to an eye-blink. Certainly, it's only the briefest hesitation.. not what I'd call "lag". These are not long enough to cause me problems of the kind described by Richard in his original post. I turned on spoken speech and found it too sometimes caused the same extremely brief glitching, but again, not enough to cause me the slightest problems in combat or scooping.

I'd like to see reports from someone with a more powerful machine, but from what I've seen, I'm inclined to think it isn't affecting Linux.

[richard.a.p.smith]

This does raise an interesting thought..

Should the F2 Options settings be recorded in the log? Might it make diagnosing certain problems easier?

On this particular point about spoken messages, if it helps, the on/off setting is recorded in the save file as far as I can tell. I couldn't work out why the spoken messages kept coming back after I'd switched them off; it was reloading a save file from before the time when I changed the setting that did it and only saving after changing made the problem go away. Rich.

[Diziet Sma]

Yes.. that's pretty much my only niggle about Oolite.. there are a few Options settings that I think ought to be set "universal" (gamma for instance) but are instead saved on an individual game-save basis.

[Diziet Sma]

To be honest, I would think that spoken messages would not really be such an issue. Certainly more processing is required for them, but the actual messages get spoken in a different game thread each time so I never considered it a potential source of problems. Definitely something we need to look at.

Turns out this was originally reported in another thread almost a year ago.. In relation to which, Wildeblood has come up with a potential area of investigation to track down the problem.. (re-posting here for convenience) If he's correct, my test above was invalid, as it was performed with a joystick. Will need to re-test Linux using the keyboard.

I eventually decided that the effect I was seeing was Oolite becoming unresponsive to the keyboard while console messages were written. If I'm pitching or yawing with the keyboard (hereinafter "slewing"), the slewing stops or slows for a fraction of a second as the message appears, then the orientation jumps to where it would have been if the slewing hadn't slowed down. This gives a noticeable stutter in the slewing. I guessed it was something to do with Oolite's buffering of key presses being interrupted and resuming.

[richard.a.p.smith]

To be honest, I would think that spoken messages would not really be such an issue. Certainly more processing is required for them, but the actual messages get spoken in a different game thread each time so I never considered it a potential source of problems. Definitely something we need to look at.

Turns out this was originally reported in another thread almost a year ago.. In relation to which, Wildeblood has come up with a potential area of investigation to track down the problem.. (re-posting here for convenience) If he's correct, my test above was invalid, as it was performed with a joystick. Will need to re-test Linux using the keyboard.

I eventually decided that the effect I was seeing was Oolite becoming unresponsive to the keyboard while console messages were written. If I'm pitching or yawing with the keyboard (hereinafter "slewing"), the slewing stops or slows for a fraction of a second as the message appears, then the orientation jumps to where it would have been if the slewing hadn't slowed down. This gives a noticeable stutter in the slewing. I guessed it was something to do with Oolite's buffering of key presses being interrupted and resuming.

Hello. There's a bit of confusion here. I started the older thread but it didn't come to anything at the time. I forgot about that post when starting this one but remembered it along the way and checked it. I also remembered Wildeblood had seen the problem so sent a PM with the solution I found and that prompted his response which you've quoted, the problem described is precisely the one I found and got around by disabling spoken messages, his description seems better than mine and suggests how Oolite is dealing with holding a given key down but the problem itself is the lag from the console message. So it's all the same thing. Good example of a reason not to post more than once on a given topic but I didn't remember the post until too late. Rich.

[Diziet Sma]

Mostly I was including that post in this current thread because it suggests a possible area of investigation as to how to fix things so that spoken messages don't cause lag, as ought to be the case..

[cim]

Not exactly. If spoken messages cause lag, then the area to fix is probably the spoken messages routine. The key stutter Wildeblood described is expected behaviour in case of lag.

Oolite simulates the frames based on the length of game time taken for that frame, which it tries to correspond to real time if possible. So if you're pressing "right", at 60FPS you'll roll 1/60 of your roll rate each frame. If there's then something happens which causes a significant delay in the simulation, the next frame is 0.25 seconds long in game time (and at least that long in real life, too), so you roll 1/4 of your roll rate in that frame. So you end up where you "should" be afterwards, but it looks like a pause and a jump as you watch it because the "video illusion" gets broken temporarily.

Anything that causes a delay will have that visible symptom, but it's a symptom, not a cause.

[Cody]

I should say that the lag I've been experiencing seems unrelated to key presses or messages (as far as I can tell, anyway).

[Diziet Sma]

Oolite simulates the frames based on the length of game time taken for that frame, which it tries to correspond to real time if possible. So if you're pressing "right", at 60FPS you'll roll 1/60 of your roll rate each frame. If there's then something happens which causes a significant delay in the simulation, the next frame is 0.25 seconds long in game time (and at least that long in real life, too), so you roll 1/4 of your roll rate in that frame. So you end up where you "should" be afterwards, but it looks like a pause and a jump as you watch it because the "video illusion" gets broken temporarily.

Anything that causes a delay will have that visible symptom, but it's a symptom, not a cause.

Ok.. many thanks for the clarification.. just a wild guess on my part that turned out to be wrong.. (again)

[cim]

Ok.. many thanks for the clarification.. just a wild guess on my part that turned out to be wrong.. (again)

Well, keep 'em coming. Plenty of times I've been following up a wild guess and fixed a bug as a result, just not the bug that caused the guess.

[Cody]

Well, keep 'em coming.

A dumb pilot can't resist such an invitation: would the display refresh rate have any bearing on lag?
If I was to switch my display's refresh rate from 75 to 60 - could the lag become less apparent?

[cim]

Well, keep 'em coming.

A dumb pilot can't resist such an invitation: would the display refresh rate have any bearing on lag?
If I was to switch my display's refresh rate from 75 to 60 - could the lag become less apparent?

Not completely impossible, though it would require a very particular combination of circumstances. If anything I'd expect it to make things very marginally worse most of the time, but give it a try anyway.

Can one of the Linux players please check and report back so that we can determine whether it is a problem of the eSpeak integration in Oolite in general or something Windows specific?

Doesn't seem to be a problem on my Linux system. (~5 years old)

[Smivs]

Can one of the Linux players please check and report back so that we can determine whether it is a problem of the eSpeak integration in Oolite in general or something Windows specific?

Doesn't seem to be a problem on my Linux system. (~5 years old)

Just checked here as well - no obvious change when spoken messages are 'on'.

[Wildeblood]

Would now be a good time to suggest making the javascript oolite.gameSettings.speechOn read/write?

[JensAyton]

Would now be a good time to suggest making the javascript oolite.gameSettings.speechOn read/write?

No.