space-crush/glc/src/angle.rs

use std::cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd};
use std::f64::consts::PI;

use auto_ops::impl_op_ex;
#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};

pub use super::numeric::{Float, Numeric};

/* Angle */

#[derive(Debug, Clone, Copy)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub enum Angle<T> {
    Deg(T),
    Rad(T),
}

impl<T> Angle<T>
where
    T: Numeric,
{
    pub fn into_inner(self) -> T {
        match self {
            Self::Deg(v) => v,
            Self::Rad(v) => v,
        }
    }

    pub fn into_deg(self) -> Self {
        match self {
            Self::Deg(v) => Self::Deg(v),
            Self::Rad(v) => Self::Rad(T::to_degrees(v)),
        }
    }

    pub fn into_rad(self) -> Self {
        match self {
            Self::Deg(v) => Self::Deg(T::to_radians(v)),
            Self::Rad(v) => Self::Rad(v),
        }
    }

    pub fn abs(self) -> Self {
        match self {
            Self::Deg(value) => Self::Deg(value.abs()),
            Self::Rad(value) => Self::Rad(value.abs()),
        }
    }

    fn _neg(self) -> Self {
        match self {
            Self::Deg(value) => Self::Deg(-value),
            Self::Rad(value) => Self::Rad(-value),
        }
    }

    fn _add(self, other: &Self) -> Self {
        match self {
            Self::Deg(value) => Self::Deg(value + other.into_deg().into_inner()),
            Self::Rad(value) => Self::Rad(value + other.into_rad().into_inner()),
        }
    }

    fn _mul(self, other: T) -> Self {
        match self {
            Self::Deg(value) => Self::Deg(value * other),
            Self::Rad(value) => Self::Rad(value * other),
        }
    }
}

impl<T> Angle<T>
where
    T: Float,
{
    pub fn sin(self) -> T {
        T::sin(self.into_rad().into_inner())
    }

    pub fn cos(self) -> T {
        T::cos(self.into_rad().into_inner())
    }

    /// Normalizes the angle to (-pi, pi] / (-180.0, 180.0]
    pub fn normalize(self) -> Self {
        match self {
            Self::Deg(value) => Self::Deg(normalize(value, T::new(-180.0), T::new(180.0))),
            Self::Rad(value) => Self::Rad(normalize(value, T::new(-PI), T::new(PI))),
        }
    }
}

impl_op_ex!(*|a: &f32, b: &Angle<f32>| -> Angle<f32> { b._mul(*a) });
impl_op_ex!(- <T: Numeric> |a: &Angle<T>| -> Angle<T> { a._neg() });
impl_op_ex!(+ <T: Numeric> |a: &Angle<T>, b: &Angle<T>| -> Angle<T> { a._add(b) });
impl_op_ex!(- <T: Numeric> |a: &Angle<T>, b: &Angle<T>| -> Angle<T> { a._add(&b._neg()) });
impl_op_ex!(* <T: Numeric> |a: &Angle<T>, b: &T| -> Angle<T> { a._mul(*b) });
impl_op_ex!(/ <T: Numeric> |a: &Angle<T>, b: &T| -> Angle<T> { a._mul(T::one() / *b) });
impl_op_ex!(+= <T: Numeric> |a: &mut Angle<T>, b: &Angle<T>| { *a = a._add(b); });
impl_op_ex!(-= <T: Numeric> |a: &mut Angle<T>, b: &Angle<T>| { *a = a._add(&b._neg()); });

impl<T, S> PartialEq<Angle<S>> for Angle<T>
where
    T: Numeric + PartialEq<S>,
    S: Numeric,
{
    fn eq(&self, other: &Angle<S>) -> bool {
        match self {
            Self::Deg(v) => v.eq(&other.into_deg().into_inner()),
            Self::Rad(v) => v.eq(&other.into_rad().into_inner()),
        }
    }
}

impl<T> Eq for Angle<T> where T: Numeric + Eq {}

impl<T, S> PartialOrd<Angle<S>> for Angle<T>
where
    T: Numeric + PartialOrd<S>,
    S: Numeric,
{
    fn partial_cmp(&self, other: &Angle<S>) -> Option<Ordering> {
        match self {
            Self::Deg(v) => v.partial_cmp(&other.into_deg().into_inner()),
            Self::Rad(v) => v.partial_cmp(&other.into_rad().into_inner()),
        }
    }
}

impl<T> Ord for Angle<T>
where
    T: Ord + Numeric,
{
    fn cmp(&self, other: &Self) -> Ordering {
        match self {
            Self::Deg(v) => v.cmp(&other.into_deg().into_inner()),
            Self::Rad(v) => v.cmp(&other.into_rad().into_inner()),
        }
    }
}

fn normalize<T>(value: T, min: T, max: T) -> T
where
    T: Float,
{
    let range = max - min;
    let value = value - min;
    let f = (value / range).floor();

    value + min - f * range
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn normalize() {
        assert_eq!(Angle::Deg(-180.0), Angle::Deg(540.0).normalize());
        assert_eq!(Angle::Deg(-180.0), Angle::Deg(180.0).normalize());
        assert_eq!(Angle::Deg(-180.0), Angle::Deg(-180.0).normalize());
        assert_eq!(Angle::Deg(-180.0), Angle::Deg(-540.0).normalize());

        assert_eq!(Angle::Deg(0.0), Angle::Deg(720.0).normalize());
        assert_eq!(Angle::Deg(0.0), Angle::Deg(360.0).normalize());
        assert_eq!(Angle::Deg(0.0), Angle::Deg(-360.0).normalize());
        assert_eq!(Angle::Deg(0.0), Angle::Deg(-720.0).normalize());

        assert_eq!(Angle::Deg(90.0), Angle::Deg(-630.0).normalize());
        assert_eq!(Angle::Deg(90.0), Angle::Deg(-270.0).normalize());
        assert_eq!(Angle::Deg(90.0), Angle::Deg(90.0).normalize());
        assert_eq!(Angle::Deg(90.0), Angle::Deg(450.0).normalize());
        assert_eq!(Angle::Deg(90.0), Angle::Deg(810.0).normalize());

        assert_eq!(Angle::Deg(-90.0), Angle::Deg(-810.0).normalize());
        assert_eq!(Angle::Deg(-90.0), Angle::Deg(-450.0).normalize());
        assert_eq!(Angle::Deg(-90.0), Angle::Deg(-90.0).normalize());
        assert_eq!(Angle::Deg(-90.0), Angle::Deg(270.0).normalize());
        assert_eq!(Angle::Deg(-90.0), Angle::Deg(630.0).normalize());
    }
}