75 lines
2.6 KiB
Rust
75 lines
2.6 KiB
Rust
extern crate alga;
|
|
extern crate nalgebra as na;
|
|
|
|
use alga::linear::FiniteDimInnerSpace;
|
|
use na::allocator::Allocator;
|
|
use na::dimension::Dim;
|
|
use na::{DefaultAllocator, RealField, Unit, Vector2, Vector3, VectorN};
|
|
|
|
/// Reflects a vector wrt. the hyperplane with normal `plane_normal`.
|
|
fn reflect_wrt_hyperplane_with_algebraic_genericity<V>(plane_normal: &Unit<V>, vector: &V) -> V
|
|
where V: FiniteDimInnerSpace + Copy {
|
|
let n = plane_normal.as_ref(); // Get the underlying vector of type `V`.
|
|
*vector - *n * (n.dot(vector) * na::convert(2.0))
|
|
}
|
|
|
|
/// Reflects a vector wrt. the hyperplane with normal `plane_normal`.
|
|
fn reflect_wrt_hyperplane_with_dimensional_genericity<N: RealField, D: Dim>(
|
|
plane_normal: &Unit<VectorN<N, D>>,
|
|
vector: &VectorN<N, D>,
|
|
) -> VectorN<N, D>
|
|
where
|
|
N: RealField,
|
|
D: Dim,
|
|
DefaultAllocator: Allocator<N, D>,
|
|
{
|
|
let n = plane_normal.as_ref(); // Get the underlying V.
|
|
vector - n * (n.dot(vector) * na::convert(2.0))
|
|
}
|
|
|
|
/// Reflects a 2D vector wrt. the 2D line with normal `plane_normal`.
|
|
fn reflect_wrt_hyperplane2<N>(plane_normal: &Unit<Vector2<N>>, vector: &Vector2<N>) -> Vector2<N>
|
|
where N: RealField {
|
|
let n = plane_normal.as_ref(); // Get the underlying Vector2
|
|
vector - n * (n.dot(vector) * na::convert(2.0))
|
|
}
|
|
|
|
/// Reflects a 3D vector wrt. the 3D plane with normal `plane_normal`.
|
|
/// /!\ This is an exact replicate of `reflect_wrt_hyperplane2, but for 3D.
|
|
fn reflect_wrt_hyperplane3<N>(plane_normal: &Unit<Vector3<N>>, vector: &Vector3<N>) -> Vector3<N>
|
|
where N: RealField {
|
|
let n = plane_normal.as_ref(); // Get the underlying Vector3
|
|
vector - n * (n.dot(vector) * na::convert(2.0))
|
|
}
|
|
|
|
fn main() {
|
|
let plane2 = Vector2::y_axis(); // 2D plane normal.
|
|
let plane3 = Vector3::y_axis(); // 3D plane normal.
|
|
|
|
let v2 = Vector2::new(1.0, 2.0); // 2D vector to be reflected.
|
|
let v3 = Vector3::new(1.0, 2.0, 3.0); // 3D vector to be reflected.
|
|
|
|
// We can call the same function for 2D and 3D.
|
|
assert_eq!(
|
|
reflect_wrt_hyperplane_with_algebraic_genericity(&plane2, &v2).y,
|
|
-2.0
|
|
);
|
|
assert_eq!(
|
|
reflect_wrt_hyperplane_with_algebraic_genericity(&plane3, &v3).y,
|
|
-2.0
|
|
);
|
|
|
|
assert_eq!(
|
|
reflect_wrt_hyperplane_with_dimensional_genericity(&plane2, &v2).y,
|
|
-2.0
|
|
);
|
|
assert_eq!(
|
|
reflect_wrt_hyperplane_with_dimensional_genericity(&plane3, &v3).y,
|
|
-2.0
|
|
);
|
|
|
|
// Call each specific implementation depending on the dimension.
|
|
assert_eq!(reflect_wrt_hyperplane2(&plane2, &v2).y, -2.0);
|
|
assert_eq!(reflect_wrt_hyperplane3(&plane3, &v3).y, -2.0);
|
|
}
|