Function tri_aspect_ratio

splashsurf_lib/src/mesh.rs:98–120

Computes the aspect ratio of the given triangle The aspect ratio is computed as the inverse of the "stretch ratio" `S` given by ```txt S = sqrt(12) * (r_in / l_max) ``` where `r_in` is the radius of the in-circle and `l_max` is the longest edge of the triangle. See e.g.: .

(
    a: &Vector3<RIn>,
    b: &Vector3<RIn>,
    c: &Vector3<RIn>,
)

/// where `r_in` is the radius of the in-circle and `l_max` is the longest edge of the triangle.
/// See e.g.: <https://www.engmorph.com/2d-element-aspect-ratio-diff-simula>.
pub fn tri_aspect_ratio<RIn: Real, RComp: Real>(
    a: &Vector3<RIn>,
    b: &Vector3<RIn>,
    c: &Vector3<RIn>,
) -> RComp {
    let two = RComp::from_i32(2).unwrap();
    let sqrt_twelve = RComp::from_i32(12).unwrap().sqrt();

    let a = a.convert::<RComp>();
    let b = b.convert::<RComp>();
    let c = c.convert::<RComp>();

    let l0 = (a - b).norm();
    let l1 = (b - c).norm();
    let l2 = (c - a).norm();
    let s = (l0 + l1 + l2) / two;

    let area: RComp = tri_area(&a, &b, &c);
    let r_in = area / s;
    let l_max = l0.max(l1.max(l2));

    l_max / (sqrt_twelve * r_in)
}

/// Utility functions for triangles meshes
pub trait TriMesh3dExt<R: Real> {