[cairo] Playing with spline decomposition

Carl Worth cworth at cworth.org
Fri Oct 17 13:07:23 PDT 2008

On Tue, 2008-10-14 at 21:56 +0100, Chris Wilson wrote:
> As the spline is immediately feed into the tessellator for
> trapezoidation, even a small reduction can have a dramatic impact on
> performance. (For example, my first foray is just a bisection search for
> the best step length, and achieves a 20% reduction in tessellation -
> about an 8% speed up for the whole benchmark).

Interesting stuff!

>  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?

Thanks, Kalle, for finding the paper. I'll have to give it a read over
the weekend.


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