[cairo] Paths as paths

[Jost Boekemeier]

On Mon, 2005-03-07 at 22:44, Carl Worth wrote:
> On Mon, 7 Mar 2005 21:21:31 +0100 (CET), Jost Boekemeier wrote:
> > > > try to detect paths that will produce problems with stroking
> > > > algorithms that convert curve => polygon before stroking and emit
> > 
> > I fail to see how this could be decided within cairo.
> well). Then the stroke outline is computed by copying from either the
> polygonal path or the pen as appropriate at various points depending
> on how the path slope changes. The theory backing up this process is
> the convolution of polygonal tracings as described by Guibas et
> al.[*].

Thank you very much for the explanation.  

But my point was to go one step further and let the backend decide if it
wants to use the original strokes or the paths -- instead of hard-coding
the decision inside of cairo (i.e. always send paths if we suspect that
the backend may do it wrong). 


> > What about fast zooming (without re-tesselating
> > everything) or what about path animations?   How
> > should we communicate these information to the
> > backend?
> 
> If we need to change anything in this area, we're going to wait until
> the profile data tell us it is necessary. For now, when I look at
> profiles, I'm seeing tessellation down below 1% of total rendering
> time, (though we still have a fair amount of rasterization and
> compositing optimization left to do, of course).

I meant sending both information to the backend, the rendered trapezoids
and the original path data attached. 


Jost