The two directions returned by this calculation are always the two boundary
conditions. Since we don't do quadrants but octants, the flagged ones are
45° each. e.g. an angle of 35° flags E and NE.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>