f64/d2/rect.go
func (r Rectangle) Center() Vec {
	return r.Min.Add(r.Max.Div(2))
}
func (r Rectangle) Center() Vec {
	return r.Min.Add(r.Max.Div(2))
}
func ( r Rectangle ) Center ( ) Vec { return r . Min . Add ( r . Max . Div ( 2 ) ) }
// Center returns the center of r.
Center returns the center of r .