MantisBT - Zandronum
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0003418Zandronum[All Projects] Bugpublic2018-05-02 13:192020-05-02 07:24
needs testingopen 
MicrosoftWindows 10Build 16299
0003418: (3.1 alpha) Stuttering ingame
While ingame connecting to a 3.1 server (or single player) the game seems to stutter alot. It does not seem to matter which mods are in use or if you are just playing vanilla doom
Load a game in single player or connect to a 3.1 server with any mod (or no mods at all) to notice this.
It's normal on 3.0 and runs smooth

I have not been able to check other OS's but it seems that both machines I have tested on (my machine and Michaelis) both run the same windows 10 build but different hardware specs. See the attached dxdiag text files for these.
No tags attached.
related to 0003334needs testing Leonard Tickrate discrepancies between clients/servers 
related to 0001633needs testing Leonard [Linux x86_64] Multiplayer game completely broken 
txt DxDiagMichaelis.txt (79,130) 2018-05-02 13:19
txt DxDiagMiFU.txt (95,969) 2018-05-02 13:19
txt DxDiagSean.txt (41,679) 2018-05-02 14:48
Issue History
2018-05-02 13:19mifuNew Issue
2018-05-02 13:19mifuFile Added: DxDiagMichaelis.txt
2018-05-02 13:19mifuFile Added: DxDiagMiFU.txt
2018-05-02 13:29mifuNote Added: 0019182
2018-05-02 13:30mifuNote Edited: 0019182bug_revision_view_page.php?bugnote_id=19182#r11501
2018-05-02 14:45AOSPNote Added: 0019183
2018-05-02 14:48AOSPFile Added: DxDiagSean.txt
2018-05-02 14:48AOSPNote Edited: 0019183bug_revision_view_page.php?bugnote_id=19183#r11503
2018-05-02 14:51AOSPNote Added: 0019184
2018-05-02 16:04LeonardNote Added: 0019188
2018-05-02 16:04LeonardAssigned To => Leonard
2018-05-02 16:04LeonardStatusnew => assigned
2018-05-02 16:04LeonardProduct Version3.0 => 3.1-beta
2018-05-02 16:04LeonardTarget Version => 3.1
2018-05-02 16:05LeonardRelationship addedrelated to 0003334
2018-05-07 09:44LeonardNote Added: 0019214
2018-05-07 09:44LeonardStatusassigned => needs testing
2018-05-07 09:44LeonardRelationship addedrelated to 0001633
2018-06-06 05:34EnsaladaDeTomateNote Added: 0019268
2018-06-06 05:43EnsaladaDeTomateNote Edited: 0019268bug_revision_view_page.php?bugnote_id=19268#r11570
2018-06-17 19:04Torr SamahoNote Added: 0019270
2018-06-18 21:54EnsaladaDeTomateNote Added: 0019275
2018-06-18 21:56EnsaladaDeTomateNote Edited: 0019275bug_revision_view_page.php?bugnote_id=19275#r11572
2018-08-22 13:45mifuNote Added: 0019382
2018-08-25 21:35unknownnaNote Added: 0019398
2018-09-10 11:28unknownnaNote Edited: 0019398bug_revision_view_page.php?bugnote_id=19398#r11773
2020-05-02 07:24mifuNote Added: 0021305

2018-05-02 13:29   
(edited on: 2018-05-02 13:30)
Forgot to mention, it also happens in software.

EDIT: Just had someone with windows XP test this on 3.1 and it happens there too

2018-05-02 14:45   
(edited on: 2018-05-02 14:48)
I don't appear to have any noticable stuttering. Testing on straight up doom2 map01, it's as smooth as 3.0.

OS: Windows 7 Enterprise N (SP1)
CPU: i5-4460
RAM: 16GB DDR3-1600
GPU: Radeon RX 580 (8GB; Radeon Software Adrenalin Edition 18.4.1)

edit: attached DxDiagSean.txt

2018-05-02 14:51   
Now that I've said I don't get struttering, I get stuttering. It's like my FPS is halved. Very weird...
2018-05-02 16:04   
I have a working fix, turns out the polled timer on windows (that is being used since 0003334) gives incorrect values for "TicStart" and "TicNext" making the "I_GetTimeFrac" function return wrong values.
I replaced the calculation for TicStart and TicNext and basically ended up with what GZDoom does after the timer refactor which made everything smooth again.
I guess we'll have to discuss how to fix this in a dev meeting.
2018-05-07 09:44   
The fix was pulled for windows but some testing is in order on Linux.
2018-06-06 05:34   
(edited on: 2018-06-06 05:43)
Tested on Zandronum 3.1-alpha-180520-0650 online and offline

The suttering is still there, but is not as severe as before.

To prove that the suttering is not completely gone, i had to do this:

In console, bind "Turn180" to any key

Spam such key and you will notice your screen suttering.

(This doesnt happen in 3.0 and lower versions of zandronum)

Edit1: The suttering is even worse if you try to move while spamming turn180

Torr Samaho   
2018-06-17 19:04   
Does this mean that you only get stuttering when using turn180?
2018-06-18 21:54   
(edited on: 2018-06-18 21:56)
Its hard to tell, sometimes i might get a very small, almost unnoticeable suttering while playing randomly, but as i stated above, spamming turn180 while moving reproduces such suttering a lot often.

Answering your question, no, i dont get suttering by only using turn180.

2018-08-22 13:45   
Sorry for late reply but the latest alpha seems to have fixed the issue for me!

Dont know about the others yet but ill see if i can round them up for some testing :)
2018-08-25 21:35   
(edited on: 2018-09-10 11:28)
I too seem to get the visual stuttering in 3.1-alpha 180520-0650 when using turn180 with cl_capfps 0. It seems to be a GZDoom issue, as it also happens in GZDoom 3.5.0.


Made a bug report on the ZDoom forums: [^]

2020-05-02 07:24   
Adding another note to advised i played some online with the latest 3.1 alpha and I do not get any stuttering