nalgebra_glm/ext/
quaternion_trigonometric.rs

1use na::{Unit, UnitQuaternion};
2
3use crate::aliases::{Qua, TVec3};
4use crate::RealNumber;
5
6/// The rotation angle of this quaternion assumed to be normalized.
7pub fn quat_angle<T: RealNumber>(x: &Qua<T>) -> T {
8    UnitQuaternion::from_quaternion(*x).angle()
9}
10
11/// Creates a quaternion from an axis and an angle.
12pub fn quat_angle_axis<T: RealNumber>(angle: T, axis: &TVec3<T>) -> Qua<T> {
13    UnitQuaternion::from_axis_angle(&Unit::new_normalize(*axis), angle).into_inner()
14}
15
16/// The rotation axis of a quaternion assumed to be normalized.
17pub fn quat_axis<T: RealNumber>(x: &Qua<T>) -> TVec3<T> {
18    if let Some(a) = UnitQuaternion::from_quaternion(*x).axis() {
19        a.into_inner()
20    } else {
21        TVec3::zeros()
22    }
23}