Add a missing file that defines the `Unit` type.

This commit is contained in:
Sébastien Crozet 2016-08-16 12:47:11 +02:00
parent c4728a33d4
commit 05a0c12c4a
1 changed files with 78 additions and 0 deletions

78
src/structs/unit.rs Normal file
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use traits::geometry::Norm;
/// A wrapper that ensures the undelying algebraic entity has a unit norm.
#[repr(C)]
#[derive(Eq, PartialEq, RustcEncodable, RustcDecodable, Clone, Hash, Debug, Copy)]
pub struct Unit<T> {
v: T
}
impl<T: Norm> Unit<T> {
/// Normalize the given value and return it wrapped on a `Unit` structure.
#[inline]
pub fn new(v: &T) -> Self {
Unit { v: v.normalize() }
}
/// Attempts to normalize the given value and return it wrapped on a `Unit` structure.
///
/// Returns `None` if the norm was smaller or equal to `min_norm`.
#[inline]
pub fn try_new(v: &T, min_norm: T::NormType) -> Option<Self> {
v.try_normalize(min_norm).map(|v| Unit { v: v })
}
/// Normalize the given value and return it wrapped on a `Unit` structure and its norm.
#[inline]
pub fn new_and_get(mut v: T) -> (Self, T::NormType) {
let n = v.normalize_mut();
(Unit { v: v }, n)
}
/// Normalize the given value and return it wrapped on a `Unit` structure and its norm.
///
/// Returns `None` if the norm was smaller or equal to `min_norm`.
#[inline]
pub fn try_new_and_get(mut v: T, min_norm: T::NormType) -> Option<(Self, T::NormType)> {
if let Some(n) = v.try_normalize_mut(min_norm) {
Some((Unit { v: v }, n))
}
else {
None
}
}
/// Normalizes this value again. This is useful when repeated computations
/// might cause a drift in the norm because of float inaccuracies.
///
/// Returns the norm beform re-normalization (should be close to `1.0`).
#[inline]
pub fn renormalize(&mut self) -> T::NormType {
self.v.normalize_mut()
}
}
impl<T> Unit<T> {
/// Wraps the given value, assuming it is already normalized.
///
/// This function is not safe because `v` is not verified to be actually normalized.
#[inline]
pub fn from_unit_value_unchecked(v: T) -> Self {
Unit { v: v }
}
/// Retrieves the underlying value.
#[inline]
pub fn unwrap(self) -> T {
self.v
}
}
impl<T> AsRef<T> for Unit<T> {
#[inline]
fn as_ref(&self) -> &T {
&self.v
}
}