Re: [Freetype-devel] Re: GSOC - Distance Fields

[Alexei Podtelezhnikov]

> > As for bezier curves, there is almost always an overflow because
> > while solving polynomials some large numbers are involved.  I even
> > tried using Newton's approximation, but it's too slow and still not
> > as accurate as floating points.

Not a good sign of numerical stability...

> Perhaps you have to subdivide the Bezier curves, using the Bezier
> envelope as a guide?

I thought about it as well: subdivide Bezier curves until the segments
are flat enough. The code can be borrowed from FreeType smooth
renderer stopping short of calculating the coverages.

> Or maybe you can do something similar to
> Behdad's `GLyphy` implementation: He uses circular arcs to approximate
> Bezier curves.

... if it is easy to work with constant curvature, then subdivide
Bezier curves until the segments have fairly constant curvature.