QRegion

Boudewijn Rempt boud at valdyas.org
Wed Jun 6 11:11:40 CEST 2007


On Wednesday 06 June 2007, Boudewijn Rempt wrote:
> On Monday 04 June 2007, Boudewijn Rempt wrote:
> > It uses internally some X11 stuff that's meant for optimizing screen
> > updates. Yes, having a class that collects rects, computes the smallest
> > set of the biggests possible rects is an interesting problem.
>
> I did think a bit on a KisRegion class and I fairly sure that I cannot make
> it work.

Apparently it's really a hard problem: Pippin doesn't have a solution either. 
I asked Zack Rusin, and he suggested to use QPainterPath and the Qt4 
tesselator. In Qt 4.4, we'll be able to add and subtract rects from a 
QPainterPath -- and we'll have access to the tesselator. That should make it 
possible to replace QRegion. Whether it'll be faster I don't know, but given 
that it's Zack working on the thing I guess it will.

Of course, we could already try to use QPainterPath together with 
toFillPolygons and then QPolygonF::boundingRect() -- but that doesn't help 
with the layer dirty region marking.

-- 
Boudewijn Rempt 
http://www.valdyas.org/fading/index.cgi
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part.
Url : http://mail.kde.org/pipermail/kimageshop/attachments/20070606/f9db613d/attachment.pgp 


More information about the kimageshop mailing list