[Kde-games-devel] Fwd: Re: SVG Rendering speed

[Aaron J. Seigo]

On Saturday 29 September 2007, Ian Wadham wrote:
> Andreas and Aaron's responses to these problems seem a bit
> Microsoftish, if you do not mind me saying so, i.e. get the next version
> of software, buy more hardware.  I am on my third Linux/KDE box

Ian, this really is a problem with x.org. the X11 protocol is ok, but the 
x.org implementation of various things are sorely lacking in many places; 
e.g. XRender is virtually hardware un-acceleratable in modern terms; this is 
a "broken by design" sort of thing. there are many such areas in x.org. 

the lack of composition based window management has been another long standing 
one that is finally getting resolved.

i don't see how saying "this sotware written by someone else is broken by 
design" is Microsoftish in the least. expose event annoyances have been there 
since KDE1 in various forms. the issue is that unless the content of the 
window itself changes, then no repaints should be requested from the window; 
exposes should be handled in the windowing system by a simple blitting of the 
already-rendered pixmap in memory.

then you can get silky smooth rendering.

there are, of course, some times we can fix things. e.g. an issue has been 
Qt's use of child windows for widgets. many (most?) of the X people said (and 
some probably continue to suggest) that this is the Right Way. Trolltech 
recently changed this and now only has one native window (the toplevel 
widget) unless otherwise requested. this results in some pretty amazing 
fluidity improvements, particularly on resize events (since we can now 
properly synchronize/minimize the painting).

the other issues you raise (SVG parsing efficiency, QPainter speed, etc) are 
independant issues. which is why i specifically replied to the part about 
windows repainting in your email. you even noted it could be an issue rooted 
in X; i was simply affirming that that is likely the case for that particular 
set of visual artifacts =)

-- 
Aaron J. Seigo
humru othro a kohnu se
GPG Fingerprint: 8B8B 2209 0C6F 7C47 B1EA  EE75 D6B7 2EB1 A7F1 DB43

KDE core developer sponsored by Trolltech
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