[cairo] Progressive slowness

[Jeff Muizelaar]

On Thu, Oct 11, 2007 at 11:11:05PM -0400, Jeff Muizelaar wrote:
> On Thu, Oct 11, 2007 at 05:12:06PM -0400, Jeff Muizelaar wrote:
> > On Thu, Oct 11, 2007 at 05:08:37PM -0400, Jeff Muizelaar wrote:
> > > On Thu, Oct 11, 2007 at 10:02:44PM +0200, Nicolas Rougier wrote:
> > > > 
> > > > Hi all,
> > > > 
> > > > I've been using cairo to do a very simple application in python: moving
> > > > and zooming a box in a window. The app (see below) is ok but when I zoom
> > > > in, the app is getting very slow and speed up again when I zoom out. I
> > > > guess I did something wrong but I cannot find it. The only reason I see
> > > > for the progressive slowness would be that I'm drawing part of the box
> > > > far beyond the visible surface (when it's zoomed in) but I thought the
> > > > clipping what responsible for handling such cases. Any idea ?
> > > > 
> > > 
> > > Looks like a rasterization problem. fbRaserizeEdges is spending a lot
> > > of time in the kernel page faulting, which is a little weird.
> > 
> > Maybe the big edges are causing a problem... I'm using cairo 1.2.6
> > here, which, ircc is before we did any clipping of the edges. It
> > wouldn't surprise me if this was fixed in git. If it isn't fixed, then
> > the problem becomes more interesting.
> 
> I don't see any slowness when using a newer version of cairo on a r200.
> Does moving to a more recent version of cairo fix the problem for you?

Also interesting, when I zoom way in, the location of things sometimes
gets swapped. I don't know what would cause this. Perhaps a precision
problem...

-Jeff