smooth painting (was: Re: Filters "dialog" in 2.0)

[Cyrille Berger]

On Wednesday 20 June 2007, Boudewijn Rempt wrote:
> > All brush strokes were cubic bezier splines. This also meant one could
> > change a stroke hours after it had been placed and it could be rendered
> > at any resolution. I'd rip code from Inscape. Their path reconstruction
> > while freehand drawing is one of the best I've seen and that include
> > commercial packages.
>
> That would be something for Cyrille to look at; I know he's been working on
> that kind of code for our freehand tool this very week.

Yes and the problem I have met to get a better result is that currently the 
stroke is rendered on the final canvas without the possibility to know the 
full path. So a few possibility are available :
- delay the drawing until the next point is available and hope the user won't 
notice (and paint with a null tangent when the cursor don't move for more 
than a second)
- keep the bezier curve (using for instance Emanuele's last year google soc), 
but the main problem is then performance when rendering the curve ( maybe 
some optimization can be done by just rerendering part of the curve thought)
- the worse is to try to guess the next move of the user (which is what we do 
currently :) ) but that's still give good enought results

-- 
Cyrille Berger