triangle_3d_area2

math_utils::geometry::primitive

Function triangle_3d_area2 

Source 
pub fn triangle_3d_area2<S>(a: &Point3<S>, b: &Point3<S>, c: &Point3<S>) -> S
where
    S: OrderedField + Sqrt,
Expand description

Square area of three points in 3D space.

Uses a numerically stable Heron’s formula: https://en.wikipedia.org/wiki/Heron%27s_formula#Numerical_stability

assert_relative_eq!(
  3.0/4.0,
  triangle_3d_area2 (
    &[-1.0,  0.0,  0.0].into(),
    &[ 0.0,  0.0,  1.0].into(),
    &[ 0.0,  1.0,  0.0].into())
);

If the area squared is zero then the points are colinear:

assert_eq!(
  0.0,
  triangle_3d_area2 (
    &[-1.0, -1.0, -1.0].into(),
    &[ 0.0,  0.0,  0.0].into(),
    &[ 1.0,  1.0,  1.0].into())
);