Patch for speeding up the painting of the autobrush

[LukasT.dev@gmail.com]

On Tuesday 02 February 2010 17:16:30 Cyrille Berger wrote:
> On Tuesday 02 February 2010, LukasT.dev at gmail.com wrote:
> > Here are the results:
> > http://lukast.mediablog.sk/i/AutoBrush_70px_rotated-new-randomLines.png
> > http://lukast.mediablog.sk/i/AutoBrush_70px_rotated-old-randomLines.png
> 
> What bother me is that when I draw at 1600%, I can't see a difference
> between valueAt and interpolatedValueAt (of course I do that with small
> mask, could the problem only appear with bigger mask ?).

Can't or can?

> > 
> >  computing the brush mask unrotated and rotate when compositing
> 
> What would be the benefit of that ?

Allows to do mipmapping which would not work with rotation. 
As I said on IRC, mip-mapping does not work for rotation. 
With this we could easily add support for rotation of the gimp brushes.