You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: cylinder.rs
    path of file: ./repos/parry/src/shape
    
    the code of the file until where you have to start completion: //! Support mapping based Cylinder shape.

use crate::math::{Point, Real, Vector};
use crate::shape::SupportMap;
use na;
use num::Zero;

#[cfg(feature = "std")]
use either::Either;

#[cfg(not(feature = "std"))]
use na::RealField; // for .copysign()

#[cfg
    
    fn local_support_point(&self, dir: &Vector<Real>) -> Point<Real> {
        let mut vres = *dir;

        vres[1] = 0.0;

        if vres.normalize_mut().is_zero() {
            vres = na::zero()
        } else {
            vres = vres * self.radius;
        }

        vres[1] = self.half_height.copysign(dir[1]);

        Point::from(vres)
    }