[cairo] Playing with spline decomposition

Chris Wilson chris at chris-wilson.co.uk
Fri Oct 17 13:28:40 PDT 2008

On Fri, 2008-10-17 at 13:07 -0700, Carl Worth wrote:
> On Tue, 2008-10-14 at 21:56 +0100, Chris Wilson wrote:
> >  The second aspect sounds
> > even more promising as it suggests that we can entirely avoid using the
> > pen whilst stroking curve segments, and generate more accurate results
> > with even fewer points.
> What are the expected savings from this part? The whole of "using the
> pen" is a linear-time walk of the flattened path with additions to
> compute points. Oh, and some slope comparisons as the path turns---is
> that what you're hoping so save here?

This is just speculation based on the few percent in the profiles spent
recomputing the convex hull at the beginning of each stroke and in
performing the linear search. But having written the
spline-decomposition test case, I can now see the importance of using
the pen as opposed to simply using the offset curves.

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