1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
extern crate nalgebra as na;
use na::allocator::Allocator;
use na::dimension::Dim;
use na::{DefaultAllocator, OVector, RealField, Unit, Vector2, Vector3};
/// Reflects a vector wrt. the hyperplane with normal `plane_normal`.
fn reflect_wrt_hyperplane_with_dimensional_genericity<T: RealField, D: Dim>(
plane_normal: &Unit<OVector<T, D>>,
vector: &OVector<T, D>,
) -> OVector<T, D>
where
T: RealField,
D: Dim,
DefaultAllocator: Allocator<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<T>(plane_normal: &Unit<Vector2<T>>, vector: &Vector2<T>) -> Vector2<T>
where
T: 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<T>(plane_normal: &Unit<Vector3<T>>, vector: &Vector3<T>) -> Vector3<T>
where
T: 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_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);
}
|
