bool TestLineCircle ( Line3d const & L, Circle const & C )
{
	return Distance2d::Distance2PointLine( C.getCenter(), L ) <= C.getRadiusSquared();
}
bool TestSegCircle ( Segment3d const & S, Circle const & C )
{
	return Distance2d::Distance2PointSeg( C.getCenter(), S ) <= C.getRadiusSquared();
}
bool TestPointCircle ( Vector const & V, Circle const & C )
{
	return Distance2d::Distance2PointPoint( C.getCenter(), V ) <= C.getRadiusSquared();
}