nalgebra/src/geometry/scale_construction.rs
2021-10-19 16:18:25 +02:00

124 lines
3.7 KiB
Rust

#[cfg(feature = "arbitrary")]
use crate::base::storage::Owned;
#[cfg(feature = "arbitrary")]
use quickcheck::{Arbitrary, Gen};
use num::One;
#[cfg(feature = "rand-no-std")]
use rand::{
distributions::{Distribution, Standard},
Rng,
};
use simba::scalar::{ClosedMul, SupersetOf};
use crate::base::{SVector, Scalar};
use crate::geometry::Scale;
impl<T: Scalar, const D: usize> Scale<T, D> {
/// Creates a new identity scale.
///
/// # Example
/// ```
/// # use nalgebra::{Point2, Point3, Scale2, Scale3};
/// let t = Scale2::identity();
/// let p = Point2::new(1.0, 2.0);
/// assert_eq!(t * p, p);
///
/// // Works in all dimensions.
/// let t = Scale3::identity();
/// let p = Point3::new(1.0, 2.0, 3.0);
/// assert_eq!(t * p, p);
/// ```
#[inline]
pub fn identity() -> Scale<T, D>
where
T: One,
{
Scale::from(SVector::from_element(T::one()))
}
/// Cast the components of `self` to another type.
///
/// # Example
/// ```
/// # use nalgebra::Scale2;
/// let tra = Scale2::new(1.0f64, 2.0);
/// let tra2 = tra.cast::<f32>();
/// assert_eq!(tra2, Scale2::new(1.0f32, 2.0));
/// ```
pub fn cast<To: Scalar>(self) -> Scale<To, D>
where
Scale<To, D>: SupersetOf<Self>,
{
crate::convert(self)
}
}
impl<T: Scalar + One + ClosedMul, const D: usize> One for Scale<T, D> {
#[inline]
fn one() -> Self {
Self::identity()
}
}
#[cfg(feature = "rand-no-std")]
impl<T: Scalar, const D: usize> Distribution<Scale<T, D>> for Standard
where
Standard: Distribution<T>,
{
/// Generate an arbitrary random variate for testing purposes.
#[inline]
fn sample<G: Rng + ?Sized>(&self, rng: &mut G) -> Scale<T, D> {
Scale::from(rng.gen::<SVector<T, D>>())
}
}
#[cfg(feature = "arbitrary")]
impl<T: Scalar + Arbitrary + Send, const D: usize> Arbitrary for Scale<T, D>
where
Owned<T, crate::Const<D>>: Send,
{
#[inline]
fn arbitrary(rng: &mut Gen) -> Self {
let v: SVector<T, D> = Arbitrary::arbitrary(rng);
Self::from(v)
}
}
/*
*
* Small Scale construction from components.
*
*/
macro_rules! componentwise_constructors_impl(
($($doc: expr; $D: expr, $($args: ident:$irow: expr),*);* $(;)*) => {$(
impl<T> Scale<T, $D>
{
#[doc = "Initializes this Scale from its components."]
#[doc = "# Example\n```"]
#[doc = $doc]
#[doc = "```"]
#[inline]
pub const fn new($($args: T),*) -> Self {
Self { vector: SVector::<T, $D>::new($($args),*) }
}
}
)*}
);
componentwise_constructors_impl!(
"# use nalgebra::Scale1;\nlet t = Scale1::new(1.0);\nassert!(t.vector.x == 1.0);";
1, x:0;
"# use nalgebra::Scale2;\nlet t = Scale2::new(1.0, 2.0);\nassert!(t.vector.x == 1.0 && t.vector.y == 2.0);";
2, x:0, y:1;
"# use nalgebra::Scale3;\nlet t = Scale3::new(1.0, 2.0, 3.0);\nassert!(t.vector.x == 1.0 && t.vector.y == 2.0 && t.vector.z == 3.0);";
3, x:0, y:1, z:2;
"# use nalgebra::Scale4;\nlet t = Scale4::new(1.0, 2.0, 3.0, 4.0);\nassert!(t.vector.x == 1.0 && t.vector.y == 2.0 && t.vector.z == 3.0 && t.vector.w == 4.0);";
4, x:0, y:1, z:2, w:3;
"# use nalgebra::Scale5;\nlet t = Scale5::new(1.0, 2.0, 3.0, 4.0, 5.0);\nassert!(t.vector.x == 1.0 && t.vector.y == 2.0 && t.vector.z == 3.0 && t.vector.w == 4.0 && t.vector.a == 5.0);";
5, x:0, y:1, z:2, w:3, a:4;
"# use nalgebra::Scale6;\nlet t = Scale6::new(1.0, 2.0, 3.0, 4.0, 5.0, 6.0);\nassert!(t.vector.x == 1.0 && t.vector.y == 2.0 && t.vector.z == 3.0 && t.vector.w == 4.0 && t.vector.a == 5.0 && t.vector.b == 6.0);";
6, x:0, y:1, z:2, w:3, a:4, b:5;
);