Function robust_geo::sign_det_x_y_x2y2z2_plus_2x_det_x_y_z

pub fn sign_det_x_y_x2y2z2_plus_2x_det_x_y_z(
    a: Vector3<f64>, 
    b: Vector3<f64>, 
    c: Vector3<f64>, 
    d: Vector3<f64>, 
    u: f64, 
    i: Vector3<f64>, 
    j: Vector3<f64>, 
    k: Vector3<f64>, 
    l: Vector3<f64>
) -> f64

Computes the following sum of determinants

│ a.x   a.y   a.x^2 + a.y^2 + a.z^2   1 │     │ i.x   i.y   i.z   1 │
│ b.x   b.y   b.x^2 + b.y^2 + b.z^2   1 │ + 2u│ j.x   j.y   j.z   1 │
│ c.x   c.y   c.x^2 + c.y^2 + c.z^2   1 │     │ k.x   k.y   k.z   1 │
│ d.x   d.y   d.x^2 + d.y^2 + d.z^2   1 │     │ l.x   l.y   l.z   1 │

and returns a number with the same sign as the sum, or 0 if the sum is 0