Opposition to removing old KWin themes?

Thomas L├╝bking thomas.luebking at web.de
Sun Jul 25 20:40:16 BST 2010


Am Sunday 25 July 2010 schrieb nuno pinheiro:
> I have extreme serious doubts that the kwin themes make any visible cpu
> difference,
a) it does (see below, also my first deco attempt like 7 years ago was so much 
inefficient that i know what i'm talking about :)
b) cpu ain't all. there's also gpu invocation and locked X11 (esp. on 
networks)

> calculating a gradient with qt is negligible work load for your
> cpu,
While Qt is pretty efficient on _creating_ gradients, using them is (on X11) 
not  :-(

Qt still* uses the RasterEngine (QImage) to create gradients and then 
XPutImage's them onto the server, what is
a) "slow" as it requires a roundtrip (xsync) for every gradient painting
b) "really slow" (tm) on remote sessions as it requires to pass the Image over 
the network

-> luckily this can be bypassed by caching the gradient, what also implicitly 
fixes the rendering bug on swapping painter engines.

*that's not Qt's fault since many XRenderCreate*Gradient implementations are 
so much f**** broken (and NO - this time it's NOT nvidias blob fault ;-)

> the only kwin theme that is a bit more expensive is Aurorae but I would
> really be surprised if that would be more than negligible.
From what i can say, Aurorae has a serious performance problem on activating 
windows here (peaks, then peaks notably again after a short delay), being a 
pain in the ass with non "click to focus" models and makes it nearby unusable 
on eg. netbooks :(


Cheers,
Thomas

ps:
i started working on an ultra cheap theme, (hopefully) looking a bit fresher 
than winblows 95, and i've a second one in my mind =)




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