[metapost] d\'ej\`a vu or turningnumber, area et caetera

[Taco Hoekwater]

Daniel H. Luecking wrote:
> 
> Did you mean  "area (t1,t2) of p"? (i.e., a <pair> of times rather than
> a <subpath>). 

No, I actually meant a <subpath>  ;-)

Using subpaths is possible because the algorithm does not care about
cyclicity (<= is that a word?)

> While area might be useful, is it really necessary to make it a
> primitive? Jacko's macro works fine by itself.

Primitives can circumvent overflow problems & retain maximum precision
much more easily.

> I've run into turningnumber only in the karta font. The characters
> were coded by giving outline paths, filling the ones with positive
> turning and unfilling the reverse of the ones with negative turning
> (one wishes for an eofill command here). 

karta.mf looks like it originally started out as karta.pfa, so that
makes sense, I guess.

Greetings, Taco