[cairo] Finding minimum distance to a stroke or fill

[Ashwin Bharambe]

Hi,

I know that cairo_in_stroke (cairo_in_fill) would answer me if a point
P was inside the stroke (fill), respectively. However, how would I go
about finding the distance of the point in the stroke/fill which is
closest to a certain point P?

Thanks,
Ashwin

PS: Oh, and I would really be happy if somebody answered this one. I
think this is definitely not very elementary. :)