Summer of Code idea: improve khtml zoom function

[Eva Brucherseifer]

Hi Fela,

I didn't read your email before today, I hope its not too late.

Am Freitag, 5. Mai 2006 16:59 schrieb Luciano Montanaro:
> On Friday 05 May 2006 16:25, Fela Winkelmolen wrote:
> > > > ...
> > > >
> > > >
> > > > The idea is to make the renderer be able to zoom in three different
> > > > ways: - fast zooming (ugly), possibly using the zooming code that
> > > > should already be somewhere to zoom images where the size is
> > > > specified in the html code, using fast zooming algorithms to scale
> > > > the images - smooth zooming (slow), using some other, more
> > > > sophisticated image zooming code (I saw showFoto scales images
> > > > nicely, for example) - zoom text only (fastest).
> > >
> > > I don't think this is needed. KHTML already uses smooth scaling for the
> > > images anyways.
> >
> > Yes? I've checked and showFoto scales the images much more nicely that
> > khtml (unless it has changed since v3.5.2). But I think it uses a slower
> > algorithm.
>
> I thought you were interested in implementing simpler scaling.
>
> Well, if I remember correctly, KHTML uses Qt smooth scaling - that is, it
> does not simply decimate pixels. There may be space for improvement,
> obviously, but it's always a compromise between speed and quality...
>
> I have checked the KDE4 tree just now, and the KHTML image handling has
> changed quite a bit from KDE 3.5. I don't know if it needs further work.

As part of my image scaling patch (see attached) patch I switched to Qt's 
smooth scaling function, as it indeed improves quality a lot. This patch 
still needs more testing and maybe some tweaks here and there. In my qt2 
versions the buttons sizing (esp height) is not perfect sometimes, but it 
also might be a Qt2 problem.

Note, that there are some other new patches in kdenox (the embedded version), 
which might be useful for konqueror. E.g. we implemented deferred loading of 
images. This means, that first all html and script code is loaded and after 
that image loading starts. This way you can see the content almost at once, 
also on embedded platforms and then you get all the images. The patch name is 
khtml_load_images_delayed_3.5.patch

A fix that is only half applied so far is findNext.patc

The directories to check are kdenox/konq-embed/kdesrc/khtml/patches. Some 
other patch directories in the kdesrc subdir also contain stuff, but khtml 
certainly has the most adaptions. All patches are against 3.5.1.

Cheers,
eva

>
> In bocca al lupo,
> Luciano

-- 
Eva Brucherseifer
General Manager

basysKom GmbH
Robert-Bosch-Str. 7 | 64293 Darmstadt | Germany
Tel: +49 6151 3969-961 | Fax: -736 | Mobile: +49 170 5533642
eva.brucherseifer at basyskom.de | www.basyskom.de
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