Slow flood fill with QPainter canvas

[LukasT.dev@gmail.com]

On Friday 05 March 2010 18:06:00 Dmitry Kazakov wrote:
> > the flood fill is still slow even we optimzed the filling algorithm.
> > Here is callgrind log of running krita with QPainter canvas
> > http://valdyas.org/~lukast/projection-floodfill.tar.gz<http://valdyas.org
> > /%7Elukast/projection-floodfill.tar.gz>
> > 
> > It seems like projection or pyramids are slow or something. The flood
> > fill is
> > also slow for OpenGL canvas. I will do the valgrinding.
> > 
> > Dmitry, can you check it out?
> 
> I looked at it briefly. It seems like a plenty of time is spent to
> KisPainter::bitBlt. New data manager api should fix this. But as for the
> KisImagePyramid, i think it should be disabled for the release, as without
> threading it is not much efficient.

I did the valgrinding  of the OpenGL and QPainter canvas again so that I can 
compare and we discovered there a lot of time is spent by converting to LAB 
colorspace. So we can't do much about it probably. I discussed to change the 
difference method for pixels per colorspace but the best way to do the 
difference is to do it in LAB. I don't know if we can do something about 
speeding up our flood fill.