forked from M-Labs/nalgebra
23 lines
684 B
Rust
23 lines
684 B
Rust
use na::{Real, Unit, UnitQuaternion};
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use aliases::{Qua, TVec3};
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/// The rotation angle of this quaternion assumed to be normalized.
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pub fn quat_angle<N: Real>(x: &Qua<N>) -> N {
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UnitQuaternion::from_quaternion(*x).angle()
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}
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/// Creates a quaternion from an axis and an angle.
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pub fn quat_angle_axis<N: Real>(angle: N, axis: &TVec3<N>) -> Qua<N> {
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UnitQuaternion::from_axis_angle(&Unit::new_normalize(*axis), angle).unwrap()
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}
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/// The rotation axis of a quaternion assumed to be normalized.
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pub fn quat_axis<N: Real>(x: &Qua<N>) -> TVec3<N> {
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if let Some(a) = UnitQuaternion::from_quaternion(*x).axis() {
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a.unwrap()
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} else {
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TVec3::zeros()
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}
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}
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