del-geo 0.1.5

2D/3D geometry utility coddes
Documentation 
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use num_traits::AsPrimitive;

pub fn nearest_to_origin<T, const X: usize>(
    p0: &nalgebra::base::SVector<T,X>, // start
    p1: &nalgebra::base::SVector<T,X>) -> nalgebra::base::SVector<T,X>
    where T: nalgebra::RealField + 'static + Copy,
          f64: num_traits::AsPrimitive<T>
{
    let d = p1 - p0;
    let a: T = d.dot(&d);
    if a < 1.0e-20_f64.as_() {
        return (p0 + p1) * 0.5_f64.as_();
    }
    let b = d.dot(&p0);
    let mut r0: T = -b / a;
    if r0 < 0_f64.as_() { r0 = 0_f64.as_(); }
    if r0 > 1_f64.as_() { r0 = 1_f64.as_(); }
    return  p0.scale(1_f64.as_() - r0) + p1.scale(r0);
}


pub fn distance_to_point<T, const X: usize>(
    po_c: &nalgebra::base::SVector<T,X>,
    po_s: &nalgebra::base::SVector<T,X>,
    po_e: &nalgebra::base::SVector<T,X>) -> T
    where T: nalgebra::RealField + 'static + Copy,
          f64: num_traits::AsPrimitive<T>
{
    return crate::edge::nearest_to_origin(&(po_s - po_c), &(po_e - po_c)).norm();
}