public override void ComputeAABB(out AABB aabb, XForm transform)
{
aabb = new AABB();
Vec2 p = transform.Position + Common.Math.Mul(transform.R, _localPosition);
aabb.LowerBound.Set(p.X - _radius, p.Y - _radius);
aabb.UpperBound.Set(p.X + _radius, p.Y + _radius);
}