nalgebra/src/geometry/rotation_specialization.rs
2018-12-29 15:32:09 +01:00

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#[cfg(feature = "arbitrary")]
use base::storage::Owned;
#[cfg(feature = "arbitrary")]
use quickcheck::{Arbitrary, Gen};
use alga::general::Real;
use num::Zero;
use rand::distributions::{Distribution, OpenClosed01, Standard};
use rand::Rng;
use std::ops::Neg;
use base::dimension::{U1, U2, U3};
use base::storage::Storage;
use base::{MatrixN, Unit, Vector, Vector1, Vector3, VectorN};
use geometry::{Rotation2, Rotation3, UnitComplex};
/*
*
* 2D Rotation matrix.
*
*/
impl<N: Real> Rotation2<N> {
/// Builds a 2 dimensional rotation matrix from an angle in radian.
///
/// # Example
///
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use std::f32;
/// # use nalgebra::{Rotation2, Point2};
/// let rot = Rotation2::new(f32::consts::FRAC_PI_2);
///
/// assert_relative_eq!(rot * Point2::new(3.0, 4.0), Point2::new(-4.0, 3.0));
/// ```
pub fn new(angle: N) -> Self {
let (sia, coa) = angle.sin_cos();
Self::from_matrix_unchecked(MatrixN::<N, U2>::new(coa, -sia, sia, coa))
}
/// Builds a 2 dimensional rotation matrix from an angle in radian wrapped in a 1-dimensional vector.
///
///
/// This is generally used in the context of generic programming. Using
/// the `::new(angle)` method instead is more common.
#[inline]
pub fn from_scaled_axis<SB: Storage<N, U1>>(axisangle: Vector<N, U1, SB>) -> Self {
Self::new(axisangle[0])
}
/// The rotation matrix required to align `a` and `b` but with its angle.
///
/// This is the rotation `R` such that `(R * a).angle(b) == 0 && (R * a).dot(b).is_positive()`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Vector2, Rotation2};
/// let a = Vector2::new(1.0, 2.0);
/// let b = Vector2::new(2.0, 1.0);
/// let rot = Rotation2::rotation_between(&a, &b);
/// assert_relative_eq!(rot * a, b);
/// assert_relative_eq!(rot.inverse() * b, a);
/// ```
#[inline]
pub fn rotation_between<SB, SC>(a: &Vector<N, U2, SB>, b: &Vector<N, U2, SC>) -> Self
where
SB: Storage<N, U2>,
SC: Storage<N, U2>,
{
::convert(UnitComplex::rotation_between(a, b).to_rotation_matrix())
}
/// The smallest rotation needed to make `a` and `b` collinear and point toward the same
/// direction, raised to the power `s`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Vector2, Rotation2};
/// let a = Vector2::new(1.0, 2.0);
/// let b = Vector2::new(2.0, 1.0);
/// let rot2 = Rotation2::scaled_rotation_between(&a, &b, 0.2);
/// let rot5 = Rotation2::scaled_rotation_between(&a, &b, 0.5);
/// assert_relative_eq!(rot2 * rot2 * rot2 * rot2 * rot2 * a, b, epsilon = 1.0e-6);
/// assert_relative_eq!(rot5 * rot5 * a, b, epsilon = 1.0e-6);
/// ```
#[inline]
pub fn scaled_rotation_between<SB, SC>(
a: &Vector<N, U2, SB>,
b: &Vector<N, U2, SC>,
s: N,
) -> Self
where
SB: Storage<N, U2>,
SC: Storage<N, U2>,
{
::convert(UnitComplex::scaled_rotation_between(a, b, s).to_rotation_matrix())
}
}
impl<N: Real> Rotation2<N> {
/// The rotation angle.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::Rotation2;
/// let rot = Rotation2::new(1.78);
/// assert_relative_eq!(rot.angle(), 1.78);
/// ```
#[inline]
pub fn angle(&self) -> N {
self.matrix()[(1, 0)].atan2(self.matrix()[(0, 0)])
}
/// The rotation angle needed to make `self` and `other` coincide.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::Rotation2;
/// let rot1 = Rotation2::new(0.1);
/// let rot2 = Rotation2::new(1.7);
/// assert_relative_eq!(rot1.angle_to(&rot2), 1.6);
/// ```
#[inline]
pub fn angle_to(&self, other: &Rotation2<N>) -> N {
self.rotation_to(other).angle()
}
/// The rotation matrix needed to make `self` and `other` coincide.
///
/// The result is such that: `self.rotation_to(other) * self == other`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::Rotation2;
/// let rot1 = Rotation2::new(0.1);
/// let rot2 = Rotation2::new(1.7);
/// let rot_to = rot1.rotation_to(&rot2);
///
/// assert_relative_eq!(rot_to * rot1, rot2);
/// assert_relative_eq!(rot_to.inverse() * rot2, rot1);
/// ```
#[inline]
pub fn rotation_to(&self, other: &Rotation2<N>) -> Rotation2<N> {
other * self.inverse()
}
/// Raise the quaternion to a given floating power, i.e., returns the rotation with the angle
/// of `self` multiplied by `n`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::Rotation2;
/// let rot = Rotation2::new(0.78);
/// let pow = rot.powf(2.0);
/// assert_relative_eq!(pow.angle(), 2.0 * 0.78);
/// ```
#[inline]
pub fn powf(&self, n: N) -> Rotation2<N> {
Self::new(self.angle() * n)
}
/// The rotation angle returned as a 1-dimensional vector.
///
/// This is generally used in the context of generic programming. Using
/// the `.angle()` method instead is more common.
#[inline]
pub fn scaled_axis(&self) -> VectorN<N, U1> {
Vector1::new(self.angle())
}
}
impl<N: Real> Distribution<Rotation2<N>> for Standard
where OpenClosed01: Distribution<N>
{
/// Generate a uniformly distributed random rotation.
#[inline]
fn sample<'a, R: Rng + ?Sized>(&self, rng: &'a mut R) -> Rotation2<N> {
Rotation2::new(rng.sample(OpenClosed01) * N::two_pi())
}
}
#[cfg(feature = "arbitrary")]
impl<N: Real + Arbitrary> Arbitrary for Rotation2<N>
where Owned<N, U2, U2>: Send
{
#[inline]
fn arbitrary<G: Gen>(g: &mut G) -> Self {
Self::new(N::arbitrary(g))
}
}
/*
*
* 3D Rotation matrix.
*
*/
impl<N: Real> Rotation3<N> {
/// Builds a 3 dimensional rotation matrix from an axis and an angle.
///
/// # Arguments
/// * `axisangle` - A vector representing the rotation. Its magnitude is the amount of rotation
/// in radian. Its direction is the axis of rotation.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use std::f32;
/// # use nalgebra::{Rotation3, Point3, Vector3};
/// let axisangle = Vector3::y() * f32::consts::FRAC_PI_2;
/// // Point and vector being transformed in the tests.
/// let pt = Point3::new(4.0, 5.0, 6.0);
/// let vec = Vector3::new(4.0, 5.0, 6.0);
/// let rot = Rotation3::new(axisangle);
///
/// assert_relative_eq!(rot * pt, Point3::new(6.0, 5.0, -4.0), epsilon = 1.0e-6);
/// assert_relative_eq!(rot * vec, Vector3::new(6.0, 5.0, -4.0), epsilon = 1.0e-6);
///
/// // A zero vector yields an identity.
/// assert_eq!(Rotation3::new(Vector3::<f32>::zeros()), Rotation3::identity());
/// ```
pub fn new<SB: Storage<N, U3>>(axisangle: Vector<N, U3, SB>) -> Self {
let axisangle = axisangle.into_owned();
let (axis, angle) = Unit::new_and_get(axisangle);
Self::from_axis_angle(&axis, angle)
}
/// Builds a 3D rotation matrix from an axis scaled by the rotation angle.
///
/// This is the same as `Self::new(axisangle)`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use std::f32;
/// # use nalgebra::{Rotation3, Point3, Vector3};
/// let axisangle = Vector3::y() * f32::consts::FRAC_PI_2;
/// // Point and vector being transformed in the tests.
/// let pt = Point3::new(4.0, 5.0, 6.0);
/// let vec = Vector3::new(4.0, 5.0, 6.0);
/// let rot = Rotation3::new(axisangle);
///
/// assert_relative_eq!(rot * pt, Point3::new(6.0, 5.0, -4.0), epsilon = 1.0e-6);
/// assert_relative_eq!(rot * vec, Vector3::new(6.0, 5.0, -4.0), epsilon = 1.0e-6);
///
/// // A zero vector yields an identity.
/// assert_eq!(Rotation3::from_scaled_axis(Vector3::<f32>::zeros()), Rotation3::identity());
/// ```
pub fn from_scaled_axis<SB: Storage<N, U3>>(axisangle: Vector<N, U3, SB>) -> Self {
Self::new(axisangle)
}
/// Builds a 3D rotation matrix from an axis and a rotation angle.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use std::f32;
/// # use nalgebra::{Rotation3, Point3, Vector3};
/// let axis = Vector3::y_axis();
/// let angle = f32::consts::FRAC_PI_2;
/// // Point and vector being transformed in the tests.
/// let pt = Point3::new(4.0, 5.0, 6.0);
/// let vec = Vector3::new(4.0, 5.0, 6.0);
/// let rot = Rotation3::from_axis_angle(&axis, angle);
///
/// assert_eq!(rot.axis().unwrap(), axis);
/// assert_eq!(rot.angle(), angle);
/// assert_relative_eq!(rot * pt, Point3::new(6.0, 5.0, -4.0), epsilon = 1.0e-6);
/// assert_relative_eq!(rot * vec, Vector3::new(6.0, 5.0, -4.0), epsilon = 1.0e-6);
///
/// // A zero vector yields an identity.
/// assert_eq!(Rotation3::from_scaled_axis(Vector3::<f32>::zeros()), Rotation3::identity());
/// ```
pub fn from_axis_angle<SB>(axis: &Unit<Vector<N, U3, SB>>, angle: N) -> Self
where SB: Storage<N, U3> {
if angle.is_zero() {
Self::identity()
} else {
let ux = axis.as_ref()[0];
let uy = axis.as_ref()[1];
let uz = axis.as_ref()[2];
let sqx = ux * ux;
let sqy = uy * uy;
let sqz = uz * uz;
let (sin, cos) = angle.sin_cos();
let one_m_cos = N::one() - cos;
Self::from_matrix_unchecked(MatrixN::<N, U3>::new(
sqx + (N::one() - sqx) * cos,
ux * uy * one_m_cos - uz * sin,
ux * uz * one_m_cos + uy * sin,
ux * uy * one_m_cos + uz * sin,
sqy + (N::one() - sqy) * cos,
uy * uz * one_m_cos - ux * sin,
ux * uz * one_m_cos - uy * sin,
uy * uz * one_m_cos + ux * sin,
sqz + (N::one() - sqz) * cos,
))
}
}
/// Creates a new rotation from Euler angles.
///
/// The primitive rotations are applied in order: 1 roll 2 pitch 3 yaw.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::Rotation3;
/// let rot = Rotation3::from_euler_angles(0.1, 0.2, 0.3);
/// let euler = rot.euler_angles();
/// assert_relative_eq!(euler.0, 0.1, epsilon = 1.0e-6);
/// assert_relative_eq!(euler.1, 0.2, epsilon = 1.0e-6);
/// assert_relative_eq!(euler.2, 0.3, epsilon = 1.0e-6);
/// ```
pub fn from_euler_angles(roll: N, pitch: N, yaw: N) -> Self {
let (sr, cr) = roll.sin_cos();
let (sp, cp) = pitch.sin_cos();
let (sy, cy) = yaw.sin_cos();
Self::from_matrix_unchecked(MatrixN::<N, U3>::new(
cy * cp,
cy * sp * sr - sy * cr,
cy * sp * cr + sy * sr,
sy * cp,
sy * sp * sr + cy * cr,
sy * sp * cr - cy * sr,
-sp,
cp * sr,
cp * cr,
))
}
/// Creates Euler angles from a rotation.
///
/// The angles are produced in the form (roll, pitch, yaw).
#[deprecated(note = "This is renamed to use `.euler_angles()`.")]
pub fn to_euler_angles(&self) -> (N, N, N) {
self.euler_angles()
}
/// Euler angles corresponding to this rotation from a rotation.
///
/// The angles are produced in the form (roll, pitch, yaw).
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::Rotation3;
/// let rot = Rotation3::from_euler_angles(0.1, 0.2, 0.3);
/// let euler = rot.euler_angles();
/// assert_relative_eq!(euler.0, 0.1, epsilon = 1.0e-6);
/// assert_relative_eq!(euler.1, 0.2, epsilon = 1.0e-6);
/// assert_relative_eq!(euler.2, 0.3, epsilon = 1.0e-6);
/// ```
pub fn euler_angles(&self) -> (N, N, N) {
// Implementation informed by "Computing Euler angles from a rotation matrix", by Gregory G. Slabaugh
// http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.371.6578
if self[(2, 0)].abs() < N::one() {
let yaw = -self[(2, 0)].asin();
let roll = (self[(2, 1)] / yaw.cos()).atan2(self[(2, 2)] / yaw.cos());
let pitch = (self[(1, 0)] / yaw.cos()).atan2(self[(0, 0)] / yaw.cos());
(roll, yaw, pitch)
} else if self[(2, 0)] <= -N::one() {
(self[(0, 1)].atan2(self[(0, 2)]), N::frac_pi_2(), N::zero())
} else {
(
-self[(0, 1)].atan2(-self[(0, 2)]),
-N::frac_pi_2(),
N::zero(),
)
}
}
/// Creates a rotation that corresponds to the local frame of an observer standing at the
/// origin and looking toward `dir`.
///
/// It maps the `z` axis to the direction `dir`.
///
/// # Arguments
/// * dir - The look direction, that is, direction the matrix `z` axis will be aligned with.
/// * up - The vertical direction. The only requirement of this parameter is to not be
/// collinear to `dir`. Non-collinearity is not checked.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use std::f32;
/// # use nalgebra::{Rotation3, Vector3};
/// let dir = Vector3::new(1.0, 2.0, 3.0);
/// let up = Vector3::y();
///
/// let rot = Rotation3::new_observer_frame(&dir, &up);
/// assert_relative_eq!(rot * Vector3::z(), dir.normalize());
/// ```
#[inline]
pub fn new_observer_frame<SB, SC>(dir: &Vector<N, U3, SB>, up: &Vector<N, U3, SC>) -> Self
where
SB: Storage<N, U3>,
SC: Storage<N, U3>,
{
let zaxis = dir.normalize();
let xaxis = up.cross(&zaxis).normalize();
let yaxis = zaxis.cross(&xaxis).normalize();
Self::from_matrix_unchecked(MatrixN::<N, U3>::new(
xaxis.x, yaxis.x, zaxis.x, xaxis.y, yaxis.y, zaxis.y, xaxis.z, yaxis.z, zaxis.z,
))
}
/// Builds a right-handed look-at view matrix without translation.
///
/// It maps the view direction `dir` to the **negative** `z` axis.
/// This conforms to the common notion of right handed look-at matrix from the computer
/// graphics community.
///
/// # Arguments
/// * dir - The direction toward which the camera looks.
/// * up - A vector approximately aligned with required the vertical axis. The only
/// requirement of this parameter is to not be collinear to `dir`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use std::f32;
/// # use nalgebra::{Rotation3, Vector3};
/// let dir = Vector3::new(1.0, 2.0, 3.0);
/// let up = Vector3::y();
///
/// let rot = Rotation3::look_at_rh(&dir, &up);
/// assert_relative_eq!(rot * dir.normalize(), -Vector3::z());
/// ```
#[inline]
pub fn look_at_rh<SB, SC>(dir: &Vector<N, U3, SB>, up: &Vector<N, U3, SC>) -> Self
where
SB: Storage<N, U3>,
SC: Storage<N, U3>,
{
Self::new_observer_frame(&dir.neg(), up).inverse()
}
/// Builds a left-handed look-at view matrix without translation.
///
/// It maps the view direction `dir` to the **positive** `z` axis.
/// This conforms to the common notion of left handed look-at matrix from the computer
/// graphics community.
///
/// # Arguments
/// * dir - The direction toward which the camera looks.
/// * up - A vector approximately aligned with required the vertical axis. The only
/// requirement of this parameter is to not be collinear to `dir`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use std::f32;
/// # use nalgebra::{Rotation3, Vector3};
/// let dir = Vector3::new(1.0, 2.0, 3.0);
/// let up = Vector3::y();
///
/// let rot = Rotation3::look_at_lh(&dir, &up);
/// assert_relative_eq!(rot * dir.normalize(), Vector3::z());
/// ```
#[inline]
pub fn look_at_lh<SB, SC>(dir: &Vector<N, U3, SB>, up: &Vector<N, U3, SC>) -> Self
where
SB: Storage<N, U3>,
SC: Storage<N, U3>,
{
Self::new_observer_frame(dir, up).inverse()
}
/// The rotation matrix required to align `a` and `b` but with its angle.
///
/// This is the rotation `R` such that `(R * a).angle(b) == 0 && (R * a).dot(b).is_positive()`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Vector3, Rotation3};
/// let a = Vector3::new(1.0, 2.0, 3.0);
/// let b = Vector3::new(3.0, 1.0, 2.0);
/// let rot = Rotation3::rotation_between(&a, &b).unwrap();
/// assert_relative_eq!(rot * a, b, epsilon = 1.0e-6);
/// assert_relative_eq!(rot.inverse() * b, a, epsilon = 1.0e-6);
/// ```
#[inline]
pub fn rotation_between<SB, SC>(a: &Vector<N, U3, SB>, b: &Vector<N, U3, SC>) -> Option<Self>
where
SB: Storage<N, U3>,
SC: Storage<N, U3>,
{
Self::scaled_rotation_between(a, b, N::one())
}
/// The smallest rotation needed to make `a` and `b` collinear and point toward the same
/// direction, raised to the power `s`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Vector3, Rotation3};
/// let a = Vector3::new(1.0, 2.0, 3.0);
/// let b = Vector3::new(3.0, 1.0, 2.0);
/// let rot2 = Rotation3::scaled_rotation_between(&a, &b, 0.2).unwrap();
/// let rot5 = Rotation3::scaled_rotation_between(&a, &b, 0.5).unwrap();
/// assert_relative_eq!(rot2 * rot2 * rot2 * rot2 * rot2 * a, b, epsilon = 1.0e-6);
/// assert_relative_eq!(rot5 * rot5 * a, b, epsilon = 1.0e-6);
/// ```
#[inline]
pub fn scaled_rotation_between<SB, SC>(
a: &Vector<N, U3, SB>,
b: &Vector<N, U3, SC>,
n: N,
) -> Option<Self>
where
SB: Storage<N, U3>,
SC: Storage<N, U3>,
{
// FIXME: code duplication with Rotation.
if let (Some(na), Some(nb)) = (a.try_normalize(N::zero()), b.try_normalize(N::zero())) {
let c = na.cross(&nb);
if let Some(axis) = Unit::try_new(c, N::default_epsilon()) {
return Some(Self::from_axis_angle(&axis, na.dot(&nb).acos() * n));
}
// Zero or PI.
if na.dot(&nb) < N::zero() {
// PI
//
// The rotation axis is undefined but the angle not zero. This is not a
// simple rotation.
return None;
}
}
Some(Self::identity())
}
/// The rotation angle in [0; pi].
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Unit, Rotation3, Vector3};
/// let axis = Unit::new_normalize(Vector3::new(1.0, 2.0, 3.0));
/// let rot = Rotation3::from_axis_angle(&axis, 1.78);
/// assert_relative_eq!(rot.angle(), 1.78);
/// ```
#[inline]
pub fn angle(&self) -> N {
((self.matrix()[(0, 0)] + self.matrix()[(1, 1)] + self.matrix()[(2, 2)] - N::one())
/ ::convert(2.0))
.acos()
}
/// The rotation axis. Returns `None` if the rotation angle is zero or PI.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Rotation3, Vector3, Unit};
/// let axis = Unit::new_normalize(Vector3::new(1.0, 2.0, 3.0));
/// let angle = 1.2;
/// let rot = Rotation3::from_axis_angle(&axis, angle);
/// assert_relative_eq!(rot.axis().unwrap(), axis);
///
/// // Case with a zero angle.
/// let rot = Rotation3::from_axis_angle(&axis, 0.0);
/// assert!(rot.axis().is_none());
/// ```
#[inline]
pub fn axis(&self) -> Option<Unit<Vector3<N>>> {
let axis = VectorN::<N, U3>::new(
self.matrix()[(2, 1)] - self.matrix()[(1, 2)],
self.matrix()[(0, 2)] - self.matrix()[(2, 0)],
self.matrix()[(1, 0)] - self.matrix()[(0, 1)],
);
Unit::try_new(axis, N::default_epsilon())
}
/// The rotation axis multiplied by the rotation angle.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Rotation3, Vector3, Unit};
/// let axisangle = Vector3::new(0.1, 0.2, 0.3);
/// let rot = Rotation3::new(axisangle);
/// assert_relative_eq!(rot.scaled_axis(), axisangle, epsilon = 1.0e-6);
/// ```
#[inline]
pub fn scaled_axis(&self) -> Vector3<N> {
if let Some(axis) = self.axis() {
axis.into_inner() * self.angle()
} else {
Vector::zero()
}
}
/// The rotation axis and angle in ]0, pi] of this unit quaternion.
///
/// Returns `None` if the angle is zero.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Rotation3, Vector3, Unit};
/// let axis = Unit::new_normalize(Vector3::new(1.0, 2.0, 3.0));
/// let angle = 1.2;
/// let rot = Rotation3::from_axis_angle(&axis, angle);
/// let axis_angle = rot.axis_angle().unwrap();
/// assert_relative_eq!(axis_angle.0, axis);
/// assert_relative_eq!(axis_angle.1, angle);
///
/// // Case with a zero angle.
/// let rot = Rotation3::from_axis_angle(&axis, 0.0);
/// assert!(rot.axis_angle().is_none());
/// ```
#[inline]
pub fn axis_angle(&self) -> Option<(Unit<Vector3<N>>, N)> {
if let Some(axis) = self.axis() {
Some((axis, self.angle()))
} else {
None
}
}
/// The rotation angle needed to make `self` and `other` coincide.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Rotation3, Vector3};
/// let rot1 = Rotation3::from_axis_angle(&Vector3::y_axis(), 1.0);
/// let rot2 = Rotation3::from_axis_angle(&Vector3::x_axis(), 0.1);
/// assert_relative_eq!(rot1.angle_to(&rot2), 1.0045657, epsilon = 1.0e-6);
/// ```
#[inline]
pub fn angle_to(&self, other: &Rotation3<N>) -> N {
self.rotation_to(other).angle()
}
/// The rotation matrix needed to make `self` and `other` coincide.
///
/// The result is such that: `self.rotation_to(other) * self == other`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Rotation3, Vector3};
/// let rot1 = Rotation3::from_axis_angle(&Vector3::y_axis(), 1.0);
/// let rot2 = Rotation3::from_axis_angle(&Vector3::x_axis(), 0.1);
/// let rot_to = rot1.rotation_to(&rot2);
/// assert_relative_eq!(rot_to * rot1, rot2, epsilon = 1.0e-6);
/// ```
#[inline]
pub fn rotation_to(&self, other: &Rotation3<N>) -> Rotation3<N> {
other * self.inverse()
}
/// Raise the quaternion to a given floating power, i.e., returns the rotation with the same
/// axis as `self` and an angle equal to `self.angle()` multiplied by `n`.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::{Rotation3, Vector3, Unit};
/// let axis = Unit::new_normalize(Vector3::new(1.0, 2.0, 3.0));
/// let angle = 1.2;
/// let rot = Rotation3::from_axis_angle(&axis, angle);
/// let pow = rot.powf(2.0);
/// assert_relative_eq!(pow.axis().unwrap(), axis, epsilon = 1.0e-6);
/// assert_eq!(pow.angle(), 2.4);
/// ```
#[inline]
pub fn powf(&self, n: N) -> Rotation3<N> {
if let Some(axis) = self.axis() {
Self::from_axis_angle(&axis, self.angle() * n)
} else if self.matrix()[(0, 0)] < N::zero() {
let minus_id = MatrixN::<N, U3>::from_diagonal_element(-N::one());
Self::from_matrix_unchecked(minus_id)
} else {
Self::identity()
}
}
}
impl<N: Real> Distribution<Rotation3<N>> for Standard
where OpenClosed01: Distribution<N>
{
/// Generate a uniformly distributed random rotation.
#[inline]
fn sample<'a, R: Rng + ?Sized>(&self, rng: &mut R) -> Rotation3<N> {
// James Arvo.
// Fast random rotation matrices.
// In D. Kirk, editor, Graphics Gems III, pages 117-120. Academic, New York, 1992.
// Compute a random rotation around Z
let theta = N::two_pi() * rng.sample(OpenClosed01);
let (ts, tc) = theta.sin_cos();
let a = MatrixN::<N, U3>::new(
tc,
ts,
N::zero(),
-ts,
tc,
N::zero(),
N::zero(),
N::zero(),
N::one(),
);
// Compute a random rotation *of* Z
let phi = N::two_pi() * rng.sample(OpenClosed01);
let z = rng.sample(OpenClosed01);
let (ps, pc) = phi.sin_cos();
let sqrt_z = z.sqrt();
let v = Vector3::new(pc * sqrt_z, ps * sqrt_z, (N::one() - z).sqrt());
let mut b = v * v.transpose();
b += b;
b -= MatrixN::<N, U3>::identity();
Rotation3::from_matrix_unchecked(b * a)
}
}
#[cfg(feature = "arbitrary")]
impl<N: Real + Arbitrary> Arbitrary for Rotation3<N>
where
Owned<N, U3, U3>: Send,
Owned<N, U3>: Send,
{
#[inline]
fn arbitrary<G: Gen>(g: &mut G) -> Self {
Self::new(VectorN::arbitrary(g))
}
}