Bug 306847

Summary: Smooth immediate window resizing (Feature Request)
Product: [Plasma] kwin Reporter: Dimitri Nüscheler <dimitri.nuescheler>
Component: effects-window-managementAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED INTENTIONAL    
Severity: wishlist CC: nate
Priority: NOR    
Version First Reported In: 4.9.0   
Target Milestone: ---   
Platform: Ubuntu   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Dimitri Nüscheler 2012-09-15 15:12:04 UTC 
I know 3 window resizing effects:
Immediate: The window content is updated during the action to fit the new resolution
Placeholder: A rectangle lets you preview the new size
Interpolate: The window content is not updated to fit the new resolution. Instead its interpolated to fit the new size.

I would now like to have Immediate & Interpolate combined. The content is interpolated, but the window content in parallel tries to update to the newest resolution. The content is expected to be delayed all the time on faster mouse movements, but with slow movements it might almost catch up, presenting a smoother look and a smoother stop of the action.


Reproducible: Always
Comment 1 Thomas Lübking 2012-09-15 16:44:53 UTC 
Tried several times (thought would be a great idea) - doesn't work.
The reason is that the permanent change between the scaled and updated variant causes "judder" - it's incredibly annoying.

If a client has sth. with slow resize performance it should cover that the best way it can itself (we do so with the preview area of the decoration kcm)

Feel free to try yourself and whenever you think you fond sth. you try it on a window with visually complex content (many buttons or so) where the scaled variant differs from the resized one visually (because part of the content is eg. of static size and moved with the window size) - if it still works, share the algorithm and we'll happily implement it.
Comment 2 Martin Flöser 2012-09-15 17:02:17 UTC 
I expect that resize experience will improve with Wayland. At least all demos I have seen had very smooth resizing (though one must say that these are extremely simple applications).

But I doubt that it is possible to resize a complex scene completely smooth. The rendering overhead is just too large and the texture from pixmap overhead is rather low compared to complex scene rendering (if a browser has to re-layout it cannot be fast)
Comment 3 Dimitri Nüscheler 2012-09-15 21:44:59 UTC 
I can imagine the judder issue can be annoying. I can think of countermeasures, but none of them doesnt introduce more complexity and other problems. Looking forward Tod Wayland, thanks.
Comment 4 Nate Graham 2022-04-26 17:03:04 UTC 
This doesn't seem relevant anymore. Window resizing is indeed hugely improved with Wayland these days.