UnreviewedradiusUnreviewedradiusBottom corner radius in user units.
UnreviewedextendHow far the head's top edge extends past the base box, in user units. A radius above 1 spends the excess here, elongating the head into an oval.
UnreviewedextendHow far the head's bottom edge extends past the base box.
Top corner radius in user units. At
HEAD_SIZE / 2the top is a semicircle; equal toradiusBottomat that value the head is a circle.