+bool
+Arc::covers (Duple const & point) const
+{
+ Duple p = window_to_item (point);
+
+ double angle_degs = atan (p.y/p.x) * 2.0 * M_PI;
+ double radius = sqrt (p.x * p.x + p.y * p.y);
+
+ return (angle_degs >= _start_degrees) &&
+ (angle_degs <= (_start_degrees + _arc_degrees)) &&
+ (radius < _radius);
+}