> > It is one of those things I never remember - winding rule of
> > truetype and postscript are different, one is even-odd, the other is
> > non-zero. [...]
> You are on the completely wrong track here. What I'm talking about is
> strictly local and not (directly) related to having two different
> contours. For example, to recognize stems and serifs, the contour
> must be the same. In case you are not aware of how the auto-hinter
> collects 'segments' and 'edges', please read
>
https://www.tug.org/TUGboat/tb24-3/lemberg.pdf> which still gives a good overview (inspite of its age and some changed
> details here and there).
Argh, sorry :-).