pub(crate) fn distance_sq<T: NumCast>(p: Point<T>, q: Point<T>) -> f64 {
    let p = p.to_f64();
    let q = q.to_f64();
    (p.x - q.x).powf(2.0) + (p.y - q.y).powf(2.0)
}
Returns the square of the Euclidean distance between two points.
src/point.rs