nalgebra/src/geometry/rotation_specialization.rs
2021-06-18 09:45:37 +02:00

987 lines
33 KiB
Rust
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#[cfg(feature = "arbitrary")]
use crate::base::storage::Owned;
#[cfg(feature = "arbitrary")]
use quickcheck::{Arbitrary, Gen};
use num::Zero;
#[cfg(feature = "rand-no-std")]
use rand::{
distributions::{uniform::SampleUniform, Distribution, OpenClosed01, Standard, Uniform},
Rng,
};
use simba::scalar::RealField;
use simba::simd::{SimdBool, SimdRealField};
use std::ops::Neg;
use crate::base::dimension::{U1, U2, U3};
use crate::base::storage::Storage;
use crate::base::{Matrix2, Matrix3, SMatrix, SVector, Unit, Vector, Vector1, Vector2, Vector3};
use crate::geometry::{Rotation2, Rotation3, UnitComplex, UnitQuaternion};
/*
*
* 2D Rotation matrix.
*
*/
/// # Construction from a 2D rotation angle
impl<T: SimdRealField> Rotation2<T> {
/// Builds a 2 dimensional rotation matrix from an angle in radian.
///
/// # Example
///
/// ```
/// # #[macro_use] extern crate approx;
/// # 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: T) -> Self {
let (sia, coa) = angle.simd_sin_cos();
Self::from_matrix_unchecked(Matrix2::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<T, U1>>(axisangle: Vector<T, U1, SB>) -> Self {
Self::new(axisangle[0])
}
}
/// # Construction from an existing 2D matrix or rotations
impl<T: SimdRealField> Rotation2<T> {
/// Builds a rotation from a basis assumed to be orthonormal.
///
/// In order to get a valid unit-quaternion, the input must be an
/// orthonormal basis, i.e., all vectors are normalized, and the are
/// all orthogonal to each other. These invariants are not checked
/// by this method.
pub fn from_basis_unchecked(basis: &[Vector2<T>; 2]) -> Self {
let mat = Matrix2::from_columns(&basis[..]);
Self::from_matrix_unchecked(mat)
}
/// Builds a rotation matrix by extracting the rotation part of the given transformation `m`.
///
/// This is an iterative method. See `.from_matrix_eps` to provide mover
/// convergence parameters and starting solution.
/// This implements "A Robust Method to Extract the Rotational Part of Deformations" by Müller et al.
pub fn from_matrix(m: &Matrix2<T>) -> Self
where
T: RealField,
{
Self::from_matrix_eps(m, T::default_epsilon(), 0, Self::identity())
}
/// Builds a rotation matrix by extracting the rotation part of the given transformation `m`.
///
/// This implements "A Robust Method to Extract the Rotational Part of Deformations" by Müller et al.
///
/// # Parameters
///
/// * `m`: the matrix from which the rotational part is to be extracted.
/// * `eps`: the angular errors tolerated between the current rotation and the optimal one.
/// * `max_iter`: the maximum number of iterations. Loops indefinitely until convergence if set to `0`.
/// * `guess`: an estimate of the solution. Convergence will be significantly faster if an initial solution close
/// to the actual solution is provided. Can be set to `Rotation2::identity()` if no other
/// guesses come to mind.
pub fn from_matrix_eps(m: &Matrix2<T>, eps: T, mut max_iter: usize, guess: Self) -> Self
where
T: RealField,
{
if max_iter == 0 {
max_iter = usize::max_value();
}
let mut rot = guess.into_inner();
for _ in 0..max_iter {
let axis = rot.column(0).perp(&m.column(0)) + rot.column(1).perp(&m.column(1));
let denom = rot.column(0).dot(&m.column(0)) + rot.column(1).dot(&m.column(1));
let angle = axis / (denom.abs() + T::default_epsilon());
if angle.abs() > eps {
rot = Self::new(angle) * rot;
} else {
break;
}
}
Self::from_matrix_unchecked(rot)
}
/// 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;
/// # 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<T, U2, SB>, b: &Vector<T, U2, SC>) -> Self
where
T: RealField,
SB: Storage<T, U2>,
SC: Storage<T, U2>,
{
crate::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;
/// # 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<T, U2, SB>,
b: &Vector<T, U2, SC>,
s: T,
) -> Self
where
T: RealField,
SB: Storage<T, U2>,
SC: Storage<T, U2>,
{
crate::convert(UnitComplex::scaled_rotation_between(a, b, s).to_rotation_matrix())
}
/// 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;
/// # 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]
#[must_use]
pub fn rotation_to(&self, other: &Self) -> Self {
other * self.inverse()
}
/// Ensure this rotation is an orthonormal rotation matrix. This is useful when repeated
/// computations might cause the matrix from progressively not being orthonormal anymore.
#[inline]
pub fn renormalize(&mut self)
where
T: RealField,
{
let mut c = UnitComplex::from(*self);
let _ = c.renormalize();
*self = Self::from_matrix_eps(self.matrix(), T::default_epsilon(), 0, c.into())
}
/// 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;
/// # 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]
#[must_use]
pub fn powf(&self, n: T) -> Self {
Self::new(self.angle() * n)
}
}
/// # 2D angle extraction
impl<T: SimdRealField> Rotation2<T> {
/// The rotation angle.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # use nalgebra::Rotation2;
/// let rot = Rotation2::new(1.78);
/// assert_relative_eq!(rot.angle(), 1.78);
/// ```
#[inline]
#[must_use]
pub fn angle(&self) -> T {
self.matrix()[(1, 0)].simd_atan2(self.matrix()[(0, 0)])
}
/// The rotation angle needed to make `self` and `other` coincide.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # 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]
#[must_use]
pub fn angle_to(&self, other: &Self) -> T {
self.rotation_to(other).angle()
}
/// 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]
#[must_use]
pub fn scaled_axis(&self) -> SVector<T, 1> {
Vector1::new(self.angle())
}
}
#[cfg(feature = "rand-no-std")]
impl<T: SimdRealField> Distribution<Rotation2<T>> for Standard
where
T::Element: SimdRealField,
T: SampleUniform,
{
/// Generate a uniformly distributed random rotation.
#[inline]
fn sample<'a, R: Rng + ?Sized>(&self, rng: &'a mut R) -> Rotation2<T> {
let twopi = Uniform::new(T::zero(), T::simd_two_pi());
Rotation2::new(rng.sample(twopi))
}
}
#[cfg(feature = "arbitrary")]
impl<T: SimdRealField + Arbitrary> Arbitrary for Rotation2<T>
where
T::Element: SimdRealField,
Owned<T, U2, U2>: Send,
{
#[inline]
fn arbitrary(g: &mut Gen) -> Self {
Self::new(T::arbitrary(g))
}
}
/*
*
* 3D Rotation matrix.
*
*/
/// # Construction from a 3D axis and/or angles
impl<T: SimdRealField> Rotation3<T>
where
T::Element: SimdRealField,
{
/// 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;
/// # 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<T, U3>>(axisangle: Vector<T, 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;
/// # 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<T, U3>>(axisangle: Vector<T, U3, SB>) -> Self {
Self::new(axisangle)
}
/// Builds a 3D rotation matrix from an axis and a rotation angle.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # 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<T, U3, SB>>, angle: T) -> Self
where
SB: Storage<T, U3>,
{
angle.simd_ne(T::zero()).if_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.simd_sin_cos();
let one_m_cos = T::one() - cos;
Self::from_matrix_unchecked(SMatrix::<T, 3, 3>::new(
sqx + (T::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 + (T::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 + (T::one() - sqz) * cos,
))
},
Self::identity,
)
}
/// 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;
/// # 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: T, pitch: T, yaw: T) -> Self {
let (sr, cr) = roll.simd_sin_cos();
let (sp, cp) = pitch.simd_sin_cos();
let (sy, cy) = yaw.simd_sin_cos();
Self::from_matrix_unchecked(SMatrix::<T, 3, 3>::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,
))
}
}
/// # Construction from a 3D eye position and target point
impl<T: SimdRealField> Rotation3<T>
where
T::Element: SimdRealField,
{
/// 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;
/// # use std::f32;
/// # use nalgebra::{Rotation3, Vector3};
/// let dir = Vector3::new(1.0, 2.0, 3.0);
/// let up = Vector3::y();
///
/// let rot = Rotation3::face_towards(&dir, &up);
/// assert_relative_eq!(rot * Vector3::z(), dir.normalize());
/// ```
#[inline]
pub fn face_towards<SB, SC>(dir: &Vector<T, U3, SB>, up: &Vector<T, U3, SC>) -> Self
where
SB: Storage<T, U3>,
SC: Storage<T, U3>,
{
let zaxis = dir.normalize();
let xaxis = up.cross(&zaxis).normalize();
let yaxis = zaxis.cross(&xaxis).normalize();
Self::from_matrix_unchecked(SMatrix::<T, 3, 3>::new(
xaxis.x, yaxis.x, zaxis.x, xaxis.y, yaxis.y, zaxis.y, xaxis.z, yaxis.z, zaxis.z,
))
}
/// Deprecated: Use [Rotation3::face_towards] instead.
#[deprecated(note = "renamed to `face_towards`")]
pub fn new_observer_frames<SB, SC>(dir: &Vector<T, U3, SB>, up: &Vector<T, U3, SC>) -> Self
where
SB: Storage<T, U3>,
SC: Storage<T, U3>,
{
Self::face_towards(dir, up)
}
/// 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;
/// # 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<T, U3, SB>, up: &Vector<T, U3, SC>) -> Self
where
SB: Storage<T, U3>,
SC: Storage<T, U3>,
{
Self::face_towards(&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;
/// # 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<T, U3, SB>, up: &Vector<T, U3, SC>) -> Self
where
SB: Storage<T, U3>,
SC: Storage<T, U3>,
{
Self::face_towards(dir, up).inverse()
}
}
/// # Construction from an existing 3D matrix or rotations
impl<T: SimdRealField> Rotation3<T>
where
T::Element: SimdRealField,
{
/// 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;
/// # 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<T, U3, SB>, b: &Vector<T, U3, SC>) -> Option<Self>
where
T: RealField,
SB: Storage<T, U3>,
SC: Storage<T, U3>,
{
Self::scaled_rotation_between(a, b, T::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;
/// # 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<T, U3, SB>,
b: &Vector<T, U3, SC>,
n: T,
) -> Option<Self>
where
T: RealField,
SB: Storage<T, U3>,
SC: Storage<T, U3>,
{
// TODO: code duplication with Rotation.
if let (Some(na), Some(nb)) = (a.try_normalize(T::zero()), b.try_normalize(T::zero())) {
let c = na.cross(&nb);
if let Some(axis) = Unit::try_new(c, T::default_epsilon()) {
return Some(Self::from_axis_angle(&axis, na.dot(&nb).acos() * n));
}
// Zero or PI.
if na.dot(&nb) < T::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 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;
/// # 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]
#[must_use]
pub fn rotation_to(&self, other: &Self) -> Self {
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;
/// # 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]
#[must_use]
pub fn powf(&self, n: T) -> Self
where
T: RealField,
{
if let Some(axis) = self.axis() {
Self::from_axis_angle(&axis, self.angle() * n)
} else if self.matrix()[(0, 0)] < T::zero() {
let minus_id = SMatrix::<T, 3, 3>::from_diagonal_element(-T::one());
Self::from_matrix_unchecked(minus_id)
} else {
Self::identity()
}
}
/// Builds a rotation from a basis assumed to be orthonormal.
///
/// In order to get a valid unit-quaternion, the input must be an
/// orthonormal basis, i.e., all vectors are normalized, and the are
/// all orthogonal to each other. These invariants are not checked
/// by this method.
pub fn from_basis_unchecked(basis: &[Vector3<T>; 3]) -> Self {
let mat = Matrix3::from_columns(&basis[..]);
Self::from_matrix_unchecked(mat)
}
/// Builds a rotation matrix by extracting the rotation part of the given transformation `m`.
///
/// This is an iterative method. See `.from_matrix_eps` to provide mover
/// convergence parameters and starting solution.
/// This implements "A Robust Method to Extract the Rotational Part of Deformations" by Müller et al.
pub fn from_matrix(m: &Matrix3<T>) -> Self
where
T: RealField,
{
Self::from_matrix_eps(m, T::default_epsilon(), 0, Self::identity())
}
/// Builds a rotation matrix by extracting the rotation part of the given transformation `m`.
///
/// This implements "A Robust Method to Extract the Rotational Part of Deformations" by Müller et al.
///
/// # Parameters
///
/// * `m`: the matrix from which the rotational part is to be extracted.
/// * `eps`: the angular errors tolerated between the current rotation and the optimal one.
/// * `max_iter`: the maximum number of iterations. Loops indefinitely until convergence if set to `0`.
/// * `guess`: a guess of the solution. Convergence will be significantly faster if an initial solution close
/// to the actual solution is provided. Can be set to `Rotation3::identity()` if no other
/// guesses come to mind.
pub fn from_matrix_eps(m: &Matrix3<T>, eps: T, mut max_iter: usize, guess: Self) -> Self
where
T: RealField,
{
if max_iter == 0 {
max_iter = usize::max_value();
}
let mut rot = guess.into_inner();
for _ in 0..max_iter {
let axis = rot.column(0).cross(&m.column(0))
+ rot.column(1).cross(&m.column(1))
+ rot.column(2).cross(&m.column(2));
let denom = rot.column(0).dot(&m.column(0))
+ rot.column(1).dot(&m.column(1))
+ rot.column(2).dot(&m.column(2));
let axisangle = axis / (denom.abs() + T::default_epsilon());
if let Some((axis, angle)) = Unit::try_new_and_get(axisangle, eps) {
rot = Rotation3::from_axis_angle(&axis, angle) * rot;
} else {
break;
}
}
Self::from_matrix_unchecked(rot)
}
/// Ensure this rotation is an orthonormal rotation matrix. This is useful when repeated
/// computations might cause the matrix from progressively not being orthonormal anymore.
#[inline]
pub fn renormalize(&mut self)
where
T: RealField,
{
let mut c = UnitQuaternion::from(*self);
let _ = c.renormalize();
*self = Self::from_matrix_eps(self.matrix(), T::default_epsilon(), 0, c.into())
}
}
/// # 3D axis and angle extraction
impl<T: SimdRealField> Rotation3<T> {
/// The rotation angle in [0; pi].
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # 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]
#[must_use]
pub fn angle(&self) -> T {
((self.matrix()[(0, 0)] + self.matrix()[(1, 1)] + self.matrix()[(2, 2)] - T::one())
/ crate::convert(2.0))
.simd_acos()
}
/// The rotation axis. Returns `None` if the rotation angle is zero or PI.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # 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]
#[must_use]
pub fn axis(&self) -> Option<Unit<Vector3<T>>>
where
T: RealField,
{
let axis = SVector::<T, 3>::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, T::default_epsilon())
}
/// The rotation axis multiplied by the rotation angle.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # 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]
#[must_use]
pub fn scaled_axis(&self) -> Vector3<T>
where
T: RealField,
{
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;
/// # 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]
#[must_use]
pub fn axis_angle(&self) -> Option<(Unit<Vector3<T>>, T)>
where
T: RealField,
{
self.axis().map(|axis| (axis, self.angle()))
}
/// The rotation angle needed to make `self` and `other` coincide.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # 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]
#[must_use]
pub fn angle_to(&self, other: &Self) -> T
where
T::Element: SimdRealField,
{
self.rotation_to(other).angle()
}
/// 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) -> (T, T, T)
where
T: RealField,
{
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;
/// # 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);
/// ```
#[must_use]
pub fn euler_angles(&self) -> (T, T, T)
where
T: RealField,
{
// Implementation informed by "Computing Euler angles from a rotation matrix", by Gregory G. Slabaugh
// https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.371.6578
if self[(2, 0)].abs() < T::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)] <= -T::one() {
(self[(0, 1)].atan2(self[(0, 2)]), T::frac_pi_2(), T::zero())
} else {
(
-self[(0, 1)].atan2(-self[(0, 2)]),
-T::frac_pi_2(),
T::zero(),
)
}
}
}
#[cfg(feature = "rand-no-std")]
impl<T: SimdRealField> Distribution<Rotation3<T>> for Standard
where
T::Element: SimdRealField,
OpenClosed01: Distribution<T>,
T: SampleUniform,
{
/// Generate a uniformly distributed random rotation.
#[inline]
fn sample<'a, R: Rng + ?Sized>(&self, rng: &mut R) -> Rotation3<T> {
// 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 twopi = Uniform::new(T::zero(), T::simd_two_pi());
let theta = rng.sample(&twopi);
let (ts, tc) = theta.simd_sin_cos();
let a = SMatrix::<T, 3, 3>::new(
tc,
ts,
T::zero(),
-ts,
tc,
T::zero(),
T::zero(),
T::zero(),
T::one(),
);
// Compute a random rotation *of* Z
let phi = rng.sample(&twopi);
let z = rng.sample(OpenClosed01);
let (ps, pc) = phi.simd_sin_cos();
let sqrt_z = z.simd_sqrt();
let v = Vector3::new(pc * sqrt_z, ps * sqrt_z, (T::one() - z).simd_sqrt());
let mut b = v * v.transpose();
b += b;
b -= SMatrix::<T, 3, 3>::identity();
Rotation3::from_matrix_unchecked(b * a)
}
}
#[cfg(feature = "arbitrary")]
impl<T: SimdRealField + Arbitrary> Arbitrary for Rotation3<T>
where
T::Element: SimdRealField,
Owned<T, U3, U3>: Send,
Owned<T, U3>: Send,
{
#[inline]
fn arbitrary(g: &mut Gen) -> Self {
Self::new(SVector::arbitrary(g))
}
}