M-Labs
/
nalgebra
3
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Cleaned up exp(), log() and powf() for Quaternion. Also, they’re for Quaternion only as we cannot define them on UnitQuaternion.

This commit is contained in:
Dimitri Sabadie 2016-07-29 17:51:35 +02:00
parent 213cc41f7d
commit 988d9272d2
1 changed files with 14 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
src/structs/quaternion.rs
View File

@ -570,24 +570,24 @@ impl<N: Arbitrary + BaseFloat> Arbitrary for UnitQuaternion<N> {
impl Quaternion<f32> { impl Quaternion<f32> {
/// Compute the exponential of a quaternion. /// Compute the exponential of a quaternion.
/// pub fn exp(&self) -> Self {
/// This function yields a `UnitQuaternion<f32>`. let v = *self.vector();
pub fn exp(&self) -> UnitQuaternion<f32> { let nn = v.norm_squared();
let v = Vector3::new(self.i, self.j, self.k);
let n = v.norm();
let z = v / n * n.sin();
UnitQuaternion::new_with_quaternion(Quaternion::new(n.cos(), z[0], z[1], z[2])) if nn.is_zero() {
::one()
} else {
let n = nn.sqrt();
let nv = v / n * n.sin();
Quaternion::new(n.cos(), nv.x, nv.y, nv.z)
}
} }
}
impl UnitQuaternion<f32> { /// Compute the natural logarithm (a.k.a ln()) of a quaternion.
/// Compute the natural logarithm (a.k.a ln()) of a unit quaternion.
/// ///
/// Becareful, this function yields a `Quaternion<f32>`, losing the unit property. /// Becareful, this function yields a `Quaternion<f32>`, losing the unit property.
pub fn log(&self) -> Quaternion<f32> { pub fn log(&self) -> Self {
let q = self.quaternion(); (Quaternion { w: 0., .. *self }).normalize() * self.w.acos()
(Quaternion { w: 0., .. *q }).normalize() * q.w.acos()
} }
/// Raise the quaternion to a given floating power. /// Raise the quaternion to a given floating power.