Minutes Monday Plasma hangout

[Fredrik Höglund]

On Wednesday 19 February 2014, David Edmundson wrote:
> On Mon, Feb 17, 2014 at 1:26 PM, Sebastian Kügler <sebas at kde.org> wrote:
> > Plasma Meeting February, 17th, 2014
> >
> > Present: Alex Fiestas, David Edmundson, Giorgos Tsiapaliokas, Marco Martin,
> > Martin Grässlin, Martin Klapetek, Jens Reuterberg, Antonis Tsiapaliokas,
> > Sebastian Kügler, Vishesh Handa,
> >
> >
> > Alex:
> > - finished wallet work (it's secure now!)
> > - works on kdeinit now (benchmarking and profiling to make it lighter)
> > - researches overlap with systemd, where can we use systemd?
> >
> > David:
> > - started notes plasmoid (davidedmundson/notes)
> > - debugging proxymodel, fixed problem
> > - fixed toolbox problems
> > - various improvements in tooltip
> > - other bugfixes
> > - profiling: looking at memory consumption of Plasma
> 
> I had a look at the code for QSGTexture, it does indeed store a cache
> of the texture as a QImage. .
> 
> Right now we do two paints SVG->QPixmap (the cache) and
> QPixmap->QImage (via QQuickPaintedItem).
> 
> This second paint is very problematic for 3 reasons:
> 1) it's another paint!
> 2) we store the image twice
> 3) we are no longer implicitly sharing the same image when we do a
> paint across images as opposed to copying a QImage.
> 
> I have just managed to make Plasma::SvgItem provide QSGNodes rather
> than inheriting from QQuickPaintedItem.
> 
> This is half way there, the next step is to port most of
> Plasma::Theme/Plasma::SVG to use QImage instead of QPixmap throughout
> (including the cache) so that we can avoid the deep copies and the
> secondary QPainting. This will mean breaking the public API(!), but it
> will be totally worth it.

It's worth noting that QPixmap::toImage() is essentially free with
the raster graphics system, as long as nothing causes the image
to detach.

Fredrik