Function ray_vs_line_segment 

pub fn ray_vs_line_segment<T: Float + SignedNumberOps<T> + FloatOps<T>>(
    r0: Vec3<T>,
    rv: Vec3<T>,
    l1: Vec3<T>,
    l2: Vec3<T>,
) -> Option<Vec3<T>>

returns the intersection point if the ray with origin r0 and direction rv intersects the line segment l1-l2