[Kde-graphics-devel] Status update

[Lars Knoll]

On Monday 03 January 2005 18:01, Mosfet wrote:
> I haven't looked at kcanvas or kpainter much, I just got KDE CVS going and
> didn't co kdenonbeta yet. I'll definitely have a look. I mostly just looked
> at the SVG stuff and Karbon. My earlier attempts at MosfetPaint had a
> painter based on the svg icon painter ;-)
>
> The main problem with doing an Arthur backend for images is, as I said, the
> brushes. Pixmapped brushes will suck because they are pixmaps, not images.
> This means they are on the X server in whatever the server depth is. Not
> only does this mean you need to convert the pixmap to an image before using
> them on your own image, (bad performance), but it will be truncated or
> dithered if your display is not truecolor, (ie 16bpp). That is the biggest
> problem IMHO. You can always cache pixmaps as images in your canvas backend
> to increase performance, but if the X server is running at 15 or 16bpp your
> going to lose color resolution. If you guys are old school you'll remember
> XPaint always warning about this ;-)

True. I've forwarded this to the arthur maintainers for consideration. Adding 
image based brushes shouldn't be too difficult.

> You'd want a brush class that has it's own image, not an X pixmap. Fonts
> are another problem, too...

Mostly solved in arthur. You can convert a rendered text string into a path 
that you can then use for drawing on your surface. Currently this only works 
for outline fonts, but we'll add support for bitmap fonts before 4.0.

> As for being directly coupled to something like libart, I don't see much
> problem with that. Libart is really useful. Who wants to recode all those
> AA graphics and path stuff? Not me ;-) As long as it's toolkit independent
> and can handle normal BGRA scanlines, (which it can), I'm happy.

Just as a sidenote: I'm reading this list and trying to forward relevant stuff 
to the arthur maintainers, but if there is stuff you need in arthur for Qt 4, 
it would be great if you could send mail to 
qt4-preview-feedback at trolltech.com.

Cheers,
Lars