Client.glide_size gets out of sync from mob.glide_size when both are 0 and a tick is missed.

ID:2024478
 
Jan 25 2016, 1:30 pm (Edited on Jan 25 2016, 2:23 pm)
BYOND Version:509
Operating System:Windows 7 Ultimate 64-bit
Web Browser:Chrome 47.0.2526.111
Applies to:Dream Seeker
Status: Open
Issue hasn't been assigned a status value.
Descriptive Problem Summary:
If you set both client.glide_size and mob.glide_size to 0, and move the mob in a variable rate, (say between 4 and 4-world.tick_lag ds (lag compensation, forgiving up to 1 world.tick_lag of delay from when they could move again to when we get a move command from them)) the client will start to fall behind the mob, catch up, repeat and basically jitter the moment byond misses a tick from overrun. a few seconds later they sync again.

It seems to happen if you manually set glide_size too, but its less noticeable, harder to trigger or pinpoint and only on fractional glide sizes.

It seems client.glide_size doesn't have issues if a tick is missed, but mob.glide_size does.

Right now all of /tg/station's code sets glide_size to 8px, I'm hoping to refactor movement code to get rid of that so we can toy around with more fps rates.

Ideally, there should be a way to just have the client follow it's eye mob's gliding, so they don't get out of sync, kinda like SYNC_STEPS but for the client. I figured this is what client.glide_size 0 does, or at least, should do.
Apr 2 2016, 7:08 pm
Bumpping, it seems to happen regardless of the steps i outlined

and it happens mainly when switching from south to west as movement direction
Apr 2 2016, 7:21 pm
Happening here too.
Apr 23 2016, 6:54 pm
Bump
Apr 23 2016, 7:32 pm
I'll put this high on my look-at list. If you have any suggestions for ways I can easily force a missed tick, that'd help.
Apr 23 2016, 8:33 pm (Edited on Apr 27 2016, 11:03 pm)
In response to Lummox JR
Lummox JR wrote:
If you have any suggestions for ways I can easily force a missed tick, that'd help.

world
    New()
        spawn(0)
            tick_miss()

proc
    tick_miss()
        while(world.tick_usage < 210);
        spawn(rand(1,10))
            .()


That being said, I modified my sight check test case to showcase it: https://tgstation13.org/msoshit/sightcheck.zip

Just move around in the box changing directions until it happens
Mar 6 2018, 1:20 pm
Bumpty bump