I think I can fix this one, but I wanted to understand something better:
When generating Postscript for fillets, I sometimes get an arc that goes
the wrong way; instead of smoothly joining the segments, it goes the
long way around and forms a large semicircle.
In looking at the code, I see that it doesn't pay attention to the order
of the angles (start and stop angles). This seems to be OK for imaging
on the screen, but Postscript requires an arc to go counterclockwise.
I think I can fix this by ensuring that end angle > start angle in
the PS arc command, but I wonder if that creates a new problem.