use approx::{AbsDiffEq, RelativeEq, UlpsEq};
use num::{One, Zero};
use std::fmt;
use std::hash;
#[cfg(feature = "serde-serialize-no-std")]
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use crate::base::allocator::Allocator;
use crate::base::dimension::{DimNameAdd, DimNameSum, U1};
use crate::base::storage::Owned;
use crate::base::{Const, DefaultAllocator, OMatrix, OVector, SVector, Scalar};
use crate::ClosedDiv;
use crate::ClosedMul;
use crate::geometry::Point;
/// A scale which supports non-uniform scaling.
#[repr(C)]
#[cfg_attr(
feature = "rkyv-serialize-no-std",
derive(rkyv::Archive, rkyv::Serialize, rkyv::Deserialize),
archive(
as = "Scale<T::Archived, D>",
bound(archive = "
T: rkyv::Archive,
SVector<T, D>: rkyv::Archive<Archived = SVector<T::Archived, D>>
")
)
)]
#[cfg_attr(feature = "rkyv-serialize", derive(bytecheck::CheckBytes))]
#[cfg_attr(feature = "cuda", derive(cust_core::DeviceCopy))]
#[derive(Copy, Clone)]
pub struct Scale<T, const D: usize> {
/// The scale coordinates, i.e., how much is multiplied to a point's coordinates when it is
/// scaled.
pub vector: SVector<T, D>,
}
impl<T: fmt::Debug, const D: usize> fmt::Debug for Scale<T, D> {
fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
self.vector.as_slice().fmt(formatter)
}
}
impl<T: Scalar + hash::Hash, const D: usize> hash::Hash for Scale<T, D>
where
Owned<T, Const<D>>: hash::Hash,
{
fn hash<H: hash::Hasher>(&self, state: &mut H) {
self.vector.hash(state)
}
}
#[cfg(feature = "bytemuck")]
unsafe impl<T, const D: usize> bytemuck::Zeroable for Scale<T, D>
where
T: Scalar + bytemuck::Zeroable,
SVector<T, D>: bytemuck::Zeroable,
{
}
#[cfg(feature = "bytemuck")]
unsafe impl<T, const D: usize> bytemuck::Pod for Scale<T, D>
where
T: Scalar + bytemuck::Pod,
SVector<T, D>: bytemuck::Pod,
{
}
#[cfg(feature = "serde-serialize-no-std")]
impl<T: Scalar, const D: usize> Serialize for Scale<T, D>
where
Owned<T, Const<D>>: Serialize,
{
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
self.vector.serialize(serializer)
}
}
#[cfg(feature = "serde-serialize-no-std")]
impl<'a, T: Scalar, const D: usize> Deserialize<'a> for Scale<T, D>
where
Owned<T, Const<D>>: Deserialize<'a>,
{
fn deserialize<Des>(deserializer: Des) -> Result<Self, Des::Error>
where
Des: Deserializer<'a>,
{
let matrix = SVector::<T, D>::deserialize(deserializer)?;
Ok(Scale::from(matrix))
}
}
impl<T: Scalar, const D: usize> Scale<T, D> {
/// Inverts `self`.
///
/// # Example
/// ```
/// # use nalgebra::{Scale2, Scale3};
/// let t = Scale3::new(1.0, 2.0, 3.0);
/// assert_eq!(t * t.try_inverse().unwrap(), Scale3::identity());
/// assert_eq!(t.try_inverse().unwrap() * t, Scale3::identity());
///
/// // Work in all dimensions.
/// let t = Scale2::new(1.0, 2.0);
/// assert_eq!(t * t.try_inverse().unwrap(), Scale2::identity());
/// assert_eq!(t.try_inverse().unwrap() * t, Scale2::identity());
///
/// // Returns None if any coordinate is 0.
/// let t = Scale2::new(0.0, 2.0);
/// assert_eq!(t.try_inverse(), None);
/// ```
#[inline]
#[must_use = "Did you mean to use try_inverse_mut()?"]
pub fn try_inverse(&self) -> Option<Scale<T, D>>
where
T: ClosedDiv + One + Zero,
{
for i in 0..D {
if self.vector[i] == T::zero() {
return None;
}
}
return Some(self.vector.map(|e| T::one() / e).into());
}
/// Inverts `self`.
///
/// # Example
/// ```
/// # use nalgebra::{Scale2, Scale3};
///
/// unsafe {
/// let t = Scale3::new(1.0, 2.0, 3.0);
/// assert_eq!(t * t.inverse_unchecked(), Scale3::identity());
/// assert_eq!(t.inverse_unchecked() * t, Scale3::identity());
///
/// // Work in all dimensions.
/// let t = Scale2::new(1.0, 2.0);
/// assert_eq!(t * t.inverse_unchecked(), Scale2::identity());
/// assert_eq!(t.inverse_unchecked() * t, Scale2::identity());
/// }
/// ```
#[inline]
#[must_use]
pub unsafe fn inverse_unchecked(&self) -> Scale<T, D>
where
T: ClosedDiv + One,
{
return self.vector.map(|e| T::one() / e).into();
}
/// Inverts `self`.
///
/// # Example
/// ```
/// # use nalgebra::{Scale2, Scale3};
/// let t = Scale3::new(1.0, 2.0, 3.0);
/// assert_eq!(t * t.pseudo_inverse(), Scale3::identity());
/// assert_eq!(t.pseudo_inverse() * t, Scale3::identity());
///
/// // Work in all dimensions.
/// let t = Scale2::new(1.0, 2.0);
/// assert_eq!(t * t.pseudo_inverse(), Scale2::identity());
/// assert_eq!(t.pseudo_inverse() * t, Scale2::identity());
///
/// // Inverts only non-zero coordinates.
/// let t = Scale2::new(0.0, 2.0);
/// assert_eq!(t * t.pseudo_inverse(), Scale2::new(0.0, 1.0));
/// assert_eq!(t.pseudo_inverse() * t, Scale2::new(0.0, 1.0));
/// ```
#[inline]
#[must_use]
pub fn pseudo_inverse(&self) -> Scale<T, D>
where
T: ClosedDiv + One + Zero,
{
return self
.vector
.map(|e| {
if e != T::zero() {
T::one() / e
} else {
T::zero()
}
})
.into();
}
/// Converts this Scale into its equivalent homogeneous transformation matrix.
///
/// # Example
/// ```
/// # use nalgebra::{Scale2, Scale3, Matrix3, Matrix4};
/// let t = Scale3::new(10.0, 20.0, 30.0);
/// let expected = Matrix4::new(10.0, 0.0, 0.0, 0.0,
/// 0.0, 20.0, 0.0, 0.0,
/// 0.0, 0.0, 30.0, 0.0,
/// 0.0, 0.0, 0.0, 1.0);
/// assert_eq!(t.to_homogeneous(), expected);
///
/// let t = Scale2::new(10.0, 20.0);
/// let expected = Matrix3::new(10.0, 0.0, 0.0,
/// 0.0, 20.0, 0.0,
/// 0.0, 0.0, 1.0);
/// assert_eq!(t.to_homogeneous(), expected);
/// ```
#[inline]
#[must_use]
pub fn to_homogeneous(&self) -> OMatrix<T, DimNameSum<Const<D>, U1>, DimNameSum<Const<D>, U1>>
where
T: Zero + One + Clone,
Const<D>: DimNameAdd<U1>,
DefaultAllocator: Allocator<T, DimNameSum<Const<D>, U1>, DimNameSum<Const<D>, U1>>
+ Allocator<T, DimNameSum<Const<D>, U1>, U1>,
{
// TODO: use self.vector.push() instead. We can’t right now because
// that would require the DimAdd bound (but here we use DimNameAdd).
// This should be fixable once Rust gets a more complete support of
// const-generics.
let mut v = OVector::from_element(T::one());
for i in 0..D {
v[i] = self.vector[i].clone();
}
return OMatrix::from_diagonal(&v);
}
/// Inverts `self` in-place.
///
/// # Example
/// ```
/// # use nalgebra::{Scale2, Scale3};
/// let t = Scale3::new(1.0, 2.0, 3.0);
/// let mut inv_t = Scale3::new(1.0, 2.0, 3.0);
/// assert!(inv_t.try_inverse_mut());
/// assert_eq!(t * inv_t, Scale3::identity());
/// assert_eq!(inv_t * t, Scale3::identity());
///
/// // Work in all dimensions.
/// let t = Scale2::new(1.0, 2.0);
/// let mut inv_t = Scale2::new(1.0, 2.0);
/// assert!(inv_t.try_inverse_mut());
/// assert_eq!(t * inv_t, Scale2::identity());
/// assert_eq!(inv_t * t, Scale2::identity());
///
/// // Does not perform any operation if a coordinate is 0.
/// let mut t = Scale2::new(0.0, 2.0);
/// assert!(!t.try_inverse_mut());
/// ```
#[inline]
pub fn try_inverse_mut(&mut self) -> bool
where
T: ClosedDiv + One + Zero,
{
if let Some(v) = self.try_inverse() {
self.vector = v.vector;
true
} else {
false
}
}
}
impl<T: Scalar + ClosedMul, const D: usize> Scale<T, D> {
/// Translate the given point.
///
/// This is the same as the multiplication `self * pt`.
///
/// # Example
/// ```
/// # use nalgebra::{Scale3, Point3};
/// let t = Scale3::new(1.0, 2.0, 3.0);
/// let transformed_point = t.transform_point(&Point3::new(4.0, 5.0, 6.0));
/// assert_eq!(transformed_point, Point3::new(4.0, 10.0, 18.0));
/// ```
#[inline]
#[must_use]
pub fn transform_point(&self, pt: &Point<T, D>) -> Point<T, D> {
self * pt
}
}
impl<T: Scalar + ClosedDiv + ClosedMul + One + Zero, const D: usize> Scale<T, D> {
/// Translate the given point by the inverse of this Scale.
///
/// # Example
/// ```
/// # use nalgebra::{Scale3, Point3};
/// let t = Scale3::new(1.0, 2.0, 3.0);
/// let transformed_point = t.try_inverse_transform_point(&Point3::new(4.0, 6.0, 6.0)).unwrap();
/// assert_eq!(transformed_point, Point3::new(4.0, 3.0, 2.0));
///
/// // Returns None if the inverse doesn't exist.
/// let t = Scale3::new(1.0, 0.0, 3.0);
/// let transformed_point = t.try_inverse_transform_point(&Point3::new(4.0, 6.0, 6.0));
/// assert_eq!(transformed_point, None);
/// ```
#[inline]
#[must_use]
pub fn try_inverse_transform_point(&self, pt: &Point<T, D>) -> Option<Point<T, D>> {
self.try_inverse().map(|s| s * pt)
}
}
impl<T: Scalar + Eq, const D: usize> Eq for Scale<T, D> {}
impl<T: Scalar + PartialEq, const D: usize> PartialEq for Scale<T, D> {
#[inline]
fn eq(&self, right: &Scale<T, D>) -> bool {
self.vector == right.vector
}
}
impl<T: Scalar + AbsDiffEq, const D: usize> AbsDiffEq for Scale<T, D>
where
T::Epsilon: Clone,
{
type Epsilon = T::Epsilon;
#[inline]
fn default_epsilon() -> Self::Epsilon {
T::default_epsilon()
}
#[inline]
fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
self.vector.abs_diff_eq(&other.vector, epsilon)
}
}
impl<T: Scalar + RelativeEq, const D: usize> RelativeEq for Scale<T, D>
where
T::Epsilon: Clone,
{
#[inline]
fn default_max_relative() -> Self::Epsilon {
T::default_max_relative()
}
#[inline]
fn relative_eq(
&self,
other: &Self,
epsilon: Self::Epsilon,
max_relative: Self::Epsilon,
) -> bool {
self.vector
.relative_eq(&other.vector, epsilon, max_relative)
}
}
impl<T: Scalar + UlpsEq, const D: usize> UlpsEq for Scale<T, D>
where
T::Epsilon: Clone,
{
#[inline]
fn default_max_ulps() -> u32 {
T::default_max_ulps()
}
#[inline]
fn ulps_eq(&self, other: &Self, epsilon: Self::Epsilon, max_ulps: u32) -> bool {
self.vector.ulps_eq(&other.vector, epsilon, max_ulps)
}
}
/*
*
* Display
*
*/
impl<T: Scalar + fmt::Display, const D: usize> fmt::Display for Scale<T, D> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let precision = f.precision().unwrap_or(3);
writeln!(f, "Scale {{")?;
write!(f, "{:.*}", precision, self.vector)?;
writeln!(f, "}}")
}
}