Jeff Pierce writes:
 > I actually wrote it that way intentionally.  Since 225 degrees and -135
 > degrees are equivalent, I went with 225 degrees because it eliminates a
 > problem with the interpolation of rotations in Squeak-Alice.

I compared arcTan: with the behaviour of the C function atan2(y,
x). This one returns values between -Pi and Pi. I found this to be more
consistent than to return values between -Pi/2 and 3*Pi/2. Ok, maybe I
shouldn't have called that a bug, but I think this should be commented
in the method.

Alex.

-- 
------  Alexander  Lazarevic  ------------------------------------------------
-- Otto-von-Guericke-Universitaet      mailto: lazarevi at cs.uni-magdeburg.de --
--   Computational Visualistics    http://www.cs.uni-magdeburg.de/~lazarevi --