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

[Ian Wadham]

On Sat, 29 Sep 2007 07:39 pm, Andreas Pakulat wrote:
> On 28.09.07 23:30:56, Aaron J. Seigo wrote:
> > On Friday 28 September 2007, Ian Wadham wrote:
> > > I do notice a big hole appearing when the initial dialog box closes,
> > > even though you can grab the dialog box and move it around rapidly
> > > without any loss of graphics quality.  And it seems to take far too
> > > long for KGameCanvas/QPainter/QWidget/X (even) to repaint over it, even
> > > though the whole main window has been loaded, rendered and painted.
> >
> > if i understand what you are saying here, this is why we really need
> > composited window managers. without them, there really is no good
> > solution to this problem.
>
> Which in turn means getting new graphics cards to everybody ;) Which is
> not a good solution either. I really wonder why KDE4 rendering is so
> much slower than KDE3 rendering for the same games.
>
This thread seems to have been split in two, some with Fwd: in the Subject
and some not.  Andreas, did you see my post on 26 Sept, at 22:51 UTC?
http://lists.kde.org/?l=kde-games-devel&m=119084712800081&w=2

The main reason KDE4 Games graphics are slower is because we are
using SVG, but in return you get a much nicer look.  The SVG overhead has
two parts, loading the SVG file and rendering it into QPixmaps.  When you
start a game, change themes or resize the playing area, those loading and
rendering overheads cut in.  I wish QSvgRenderer could be faster.  OTOH
you only pay that overhead a lot if you keep re-sizing and chopping and
changing themes.  I believe most players will not do that often, once the
novelty has worn off ...

Personally, I think the overhead is well worth paying, judging by the
response I received to some "before and after" slides I presented at a
local Linux users' group early in September.  Most of this group are die-hard
Gnome supporters and rather anti-KDE, but there were audible gasps from
the audience when our new graphics appeared on the screen.  Make no
mistake, guys, we are on a winner here! ... :-D :-D

However, there still seem to be some slownesses in the *painting* of
the QPixmaps, whether you use QGraphicsView, KGameCanvas or
hand-coded QPainter to compose and update a picture as each game
progresses in its play ...

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
and none of them have fully supported the on-board graphics ...

Indeed it appears that acquiring a current-generation laptop that is
fully supported by Linux is quite a black art ...  Nevertheless, I have
promised myself a new laptop for Christmas and have located a
guy in the Silicon Valley area who can help direct the research I
need to do to avoid getting my fingers burnt a fourth time ...  Maybe
the solution will be to buy a Dell box with Linux pre-installed, but
they are not available in Australia yet.

I know this is not the fault of Linux and KDE, when Intel and the
graphics card manufacturers keep changing the hardware so fast,
but Linux and KDE feel the effects worst.  And besides, I would like to
feel that people in Africa and India can enjoy our games, even if they
do not have the latest and greatest machines.

Gloomily, Ian W.