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use approx::{AbsDiffEq, RelativeEq, UlpsEq};
use num_complex::Complex;
use std::fmt;
use alga::general::Real;
use base::{Matrix2, Matrix3, Unit, Vector1};
use geometry::Rotation2;
/// A complex number with a norm equal to 1.
pub type UnitComplex<N> = Unit<Complex<N>>;
impl<N: Real> UnitComplex<N> {
/// The rotation angle in `]-pi; pi]` of this unit complex number.
///
/// # Example
/// ```
/// # use nalgebra::UnitComplex;
/// let rot = UnitComplex::new(1.78);
/// assert_eq!(rot.angle(), 1.78);
/// ```
#[inline]
pub fn angle(&self) -> N {
self.im.atan2(self.re)
}
/// The sine of the rotation angle.
///
/// # Example
/// ```
/// # use nalgebra::UnitComplex;
/// let angle = 1.78f32;
/// let rot = UnitComplex::new(angle);
/// assert_eq!(rot.sin_angle(), angle.sin());
/// ```
#[inline]
pub fn sin_angle(&self) -> N {
self.im
}
/// The cosine of the rotation angle.
///
/// # Example
/// ```
/// # use nalgebra::UnitComplex;
/// let angle = 1.78f32;
/// let rot = UnitComplex::new(angle);
/// assert_eq!(rot.cos_angle(),angle.cos());
/// ```
#[inline]
pub fn cos_angle(&self) -> N {
self.re
}
/// 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) -> Vector1<N> {
Vector1::new(self.angle())
}
/// The rotation axis and angle in ]0, pi] of this complex number.
///
/// This is generally used in the context of generic programming. Using
/// the `.angle()` method instead is more common.
/// Returns `None` if the angle is zero.
#[inline]
pub fn axis_angle(&self) -> Option<(Unit<Vector1<N>>, N)> {
let ang = self.angle();
if ang.is_zero() {
None
} else if ang.is_sign_negative() {
Some((Unit::new_unchecked(Vector1::x()), -ang))
} else {
Some((Unit::new_unchecked(-Vector1::<N>::x()), ang))
}
}
/// The underlying complex number.
///
/// Same as `self.as_ref()`.
///
/// # Example
/// ```
/// # extern crate num_complex;
/// # extern crate nalgebra;
/// # use num_complex::Complex;
/// # use nalgebra::UnitComplex;
/// let angle = 1.78f32;
/// let rot = UnitComplex::new(angle);
/// assert_eq!(*rot.complex(), Complex::new(angle.cos(), angle.sin()));
/// ```
#[inline]
pub fn complex(&self) -> &Complex<N> {
self.as_ref()
}
/// Compute the conjugate of this unit complex number.
///
/// # Example
/// ```
/// # use nalgebra::UnitComplex;
/// let rot = UnitComplex::new(1.78);
/// let conj = rot.conjugate();
/// assert_eq!(rot.complex().im, -conj.complex().im);
/// assert_eq!(rot.complex().re, conj.complex().re);
/// ```
#[inline]
pub fn conjugate(&self) -> Self {
UnitComplex::new_unchecked(self.conj())
}
/// Inverts this complex number if it is not zero.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::UnitComplex;
/// let rot = UnitComplex::new(1.2);
/// let inv = rot.inverse();
/// assert_relative_eq!(rot * inv, UnitComplex::identity(), epsilon = 1.0e-6);
/// assert_relative_eq!(inv * rot, UnitComplex::identity(), epsilon = 1.0e-6);
/// ```
#[inline]
pub fn inverse(&self) -> Self {
self.conjugate()
}
/// The rotation angle needed to make `self` and `other` coincide.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::UnitComplex;
/// let rot1 = UnitComplex::new(0.1);
/// let rot2 = UnitComplex::new(1.7);
/// assert_relative_eq!(rot1.angle_to(&rot2), 1.6);
/// ```
#[inline]
pub fn angle_to(&self, other: &Self) -> N {
let delta = self.rotation_to(other);
delta.angle()
}
/// The unit complex number 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::UnitComplex;
/// let rot1 = UnitComplex::new(0.1);
/// let rot2 = UnitComplex::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: &Self) -> Self {
other / self
}
/// Compute in-place the conjugate of this unit complex number.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::UnitComplex;
/// let angle = 1.7;
/// let rot = UnitComplex::new(angle);
/// let mut conj = UnitComplex::new(angle);
/// conj.conjugate_mut();
/// assert_eq!(rot.complex().im, -conj.complex().im);
/// assert_eq!(rot.complex().re, conj.complex().re);
/// ```
#[inline]
pub fn conjugate_mut(&mut self) {
let me = self.as_mut_unchecked();
me.im = -me.im;
}
/// Inverts in-place this unit complex number.
///
/// # Example
/// ```
/// # #[macro_use] extern crate approx;
/// # extern crate nalgebra;
/// # use nalgebra::UnitComplex;
/// let angle = 1.7;
/// let mut rot = UnitComplex::new(angle);
/// rot.inverse_mut();
/// assert_relative_eq!(rot * UnitComplex::new(angle), UnitComplex::identity());
/// assert_relative_eq!(UnitComplex::new(angle) * rot, UnitComplex::identity());
/// ```
#[inline]
pub fn inverse_mut(&mut self) {
self.conjugate_mut()
}
/// Raise this unit complex number to a given floating power.
///
/// This returns the unit complex number that identifies a rotation angle equal to
/// `self.angle() × n`.
///
/// # Example
/// ```
/// # use nalgebra::UnitComplex;
/// let rot = UnitComplex::new(0.78);
/// let pow = rot.powf(2.0);
/// assert_eq!(pow.angle(), 2.0 * 0.78);
/// ```
#[inline]
pub fn powf(&self, n: N) -> Self {
Self::from_angle(self.angle() * n)
}
/// Builds the rotation matrix corresponding to this unit complex number.
///
/// # Example
/// ```
/// # use nalgebra::{UnitComplex, Rotation2};
/// # use std::f32;
/// let rot = UnitComplex::new(f32::consts::FRAC_PI_6);
/// let expected = Rotation2::new(f32::consts::FRAC_PI_6);
/// assert_eq!(rot.to_rotation_matrix(), expected);
/// ```
#[inline]
pub fn to_rotation_matrix(&self) -> Rotation2<N> {
let r = self.re;
let i = self.im;
Rotation2::from_matrix_unchecked(Matrix2::new(r, -i, i, r))
}
/// Converts this unit complex number into its equivalent homogeneous transformation matrix.
///
/// # Example
/// ```
/// # use nalgebra::{UnitComplex, Matrix3};
/// # use std::f32;
/// let rot = UnitComplex::new(f32::consts::FRAC_PI_6);
/// let expected = Matrix3::new(0.8660254, -0.5, 0.0,
/// 0.5, 0.8660254, 0.0,
/// 0.0, 0.0, 1.0);
/// assert_eq!(rot.to_homogeneous(), expected);
/// ```
#[inline]
pub fn to_homogeneous(&self) -> Matrix3<N> {
self.to_rotation_matrix().to_homogeneous()
}
}
impl<N: Real + fmt::Display> fmt::Display for UnitComplex<N> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "UnitComplex angle: {}", self.angle())
}
}
impl<N: Real> AbsDiffEq for UnitComplex<N> {
type Epsilon = N;
#[inline]
fn default_epsilon() -> Self::Epsilon {
N::default_epsilon()
}
#[inline]
fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
self.re.abs_diff_eq(&other.re, epsilon) && self.im.abs_diff_eq(&other.im, epsilon)
}
}
impl<N: Real> RelativeEq for UnitComplex<N> {
#[inline]
fn default_max_relative() -> Self::Epsilon {
N::default_max_relative()
}
#[inline]
fn relative_eq(
&self,
other: &Self,
epsilon: Self::Epsilon,
max_relative: Self::Epsilon,
) -> bool
{
self.re.relative_eq(&other.re, epsilon, max_relative)
&& self.im.relative_eq(&other.im, epsilon, max_relative)
}
}
impl<N: Real> UlpsEq for UnitComplex<N> {
#[inline]
fn default_max_ulps() -> u32 {
N::default_max_ulps()
}
#[inline]
fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
self.re.ulps_eq(&other.re, epsilon, max_ulps)
&& self.im.ulps_eq(&other.im, epsilon, max_ulps)
}
}
impl<N: Real> From<UnitComplex<N>> for Matrix3<N> {
#[inline]
fn from(q: UnitComplex<N>) -> Matrix3<N> {
q.to_homogeneous()
}
}
impl<N: Real> From<UnitComplex<N>> for Matrix2<N> {
#[inline]
fn from(q: UnitComplex<N>) -> Matrix2<N> {
q.to_rotation_matrix().unwrap()
}
}