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|
use super::*;
use decorum::N64;
/// An angle.
#[derive(Default, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct Angle(N64);
impl Angle {
/// The zero angle.
pub fn zero() -> Self {
Self(N64::from(0.0))
}
/// Create an angle from a number of radians.
pub fn rad(rad: f64) -> Self {
Self::with_unit(rad, AngularUnit::Rad)
}
/// Create an angle from a number of degrees.
pub fn deg(deg: f64) -> Self {
Self::with_unit(deg, AngularUnit::Deg)
}
/// Create an angle from a number of raw units.
pub fn raw(raw: f64) -> Self {
Self(N64::from(raw))
}
/// Convert this to a number of radians.
pub fn to_rad(self) -> f64 {
self.to_unit(AngularUnit::Rad)
}
/// Convert this to a number of degrees.
pub fn to_deg(self) -> f64 {
self.to_unit(AngularUnit::Deg)
}
/// Get the value of this angle in raw units.
pub fn to_raw(self) -> f64 {
self.0.into()
}
/// Create an angle from a value in a unit.
pub fn with_unit(val: f64, unit: AngularUnit) -> Self {
Self(N64::from(val * unit.raw_scale()))
}
/// Get the value of this length in unit.
pub fn to_unit(self, unit: AngularUnit) -> f64 {
self.to_raw() / unit.raw_scale()
}
}
impl Display for Angle {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
// Format with the unit that yields the shortest output, preferring
// degrees when tied.
let unit = [AngularUnit::Deg, AngularUnit::Rad]
.iter()
.copied()
.min_by_key(|&unit| self.to_unit(unit).to_string().len())
.unwrap();
write!(f, "{}{}", self.to_unit(unit), unit)
}
}
impl Debug for Angle {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
let unit = AngularUnit::Deg;
write!(f, "{}{}", self.to_unit(unit), unit)
}
}
impl Neg for Angle {
type Output = Self;
fn neg(self) -> Self {
Self(-self.0)
}
}
impl Add for Angle {
type Output = Self;
fn add(self, other: Self) -> Self {
Self(self.0 + other.0)
}
}
sub_impl!(Angle - Angle -> Angle);
impl Mul<f64> for Angle {
type Output = Self;
fn mul(self, other: f64) -> Self {
Self(self.0 * other)
}
}
impl Mul<Angle> for f64 {
type Output = Angle;
fn mul(self, other: Angle) -> Angle {
other * self
}
}
impl Div<f64> for Angle {
type Output = Self;
fn div(self, other: f64) -> Self {
Self(self.0 / other)
}
}
impl Div for Angle {
type Output = f64;
fn div(self, other: Self) -> f64 {
self.to_raw() / other.to_raw()
}
}
assign_impl!(Angle += Angle);
assign_impl!(Angle -= Angle);
assign_impl!(Angle *= f64);
assign_impl!(Angle /= f64);
impl Sum for Angle {
fn sum<I: Iterator<Item = Angle>>(iter: I) -> Self {
iter.fold(Angle::zero(), Add::add)
}
}
/// Different units of angular measurement.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
pub enum AngularUnit {
/// Radians.
Rad,
/// Degrees.
Deg,
}
impl AngularUnit {
/// How many raw units correspond to a value of `1.0` in this unit.
fn raw_scale(self) -> f64 {
match self {
Self::Rad => 1.0,
Self::Deg => PI / 180.0,
}
}
}
impl Display for AngularUnit {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
f.pad(match self {
Self::Rad => "rad",
Self::Deg => "deg",
})
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_angle_unit_conversion() {
assert!((Angle::rad(2.0 * PI).to_deg() - 360.0) < 1e-4);
assert!((Angle::deg(45.0).to_rad() - 0.7854) < 1e-4);
}
}
|
