[metapost] Problem with quartercircle

[Taco Hoekwater]

Pétiard François wrote:
> Why the second quartercircle isn't cut after z1 ?

The point z1 is not *on* the path qd, but only coincident with it.

Do it like this:

   z1=point(xpart (qd intersectiontimes((0,0)--(4cm,4cm)))) of qd;

Cheers, Taco