Polygon magic!

[David Feuer]

I haven't written the code yet, but I have, conceptually at least,
completely solved the problem of unfilled rounded polygons in both
PostScript and SVG.  The key is to use the outline as a clipping path,
and create path that coincides with it everywhere except perhaps at
the corners which is stroked.  The outline is redrawn (or whatever)
and the region between the paths is filled.  This gives an overall
thickness parameter, and two parameters for each vertex: outer radius,
inner radius, and line thickness.  If necessary, it should even be
possible to make the different edges have different thicknesses.

David