cp_library_rs/algebraic_structure/
affine2d.rs

1//! 2次元Affine変換
2//!
3//! 2次元平面上の点の回転
4
5#![allow(clippy::needless_range_loop)]
6
7/// # AffineMatrix
8/// アフィン変換（3x3行列）
9#[derive(Debug, Clone, Copy)]
10pub struct AffineMatrix {
11    pub arr: [[isize; 3]; 3],
12}
13
14impl AffineMatrix {
15    pub fn e() -> Self {
16        Self {
17            arr: [[1, 0, 0], [0, 1, 0], [0, 0, 1]],
18        }
19    }
20
21    pub fn rotate90() -> Self {
22        Self {
23            arr: [[0, -1, 0], [1, 0, 0], [0, 0, 1]],
24        }
25    }
26
27    pub fn rotate270() -> Self {
28        Self {
29            arr: [[0, 1, 0], [-1, 0, 0], [0, 0, 1]],
30        }
31    }
32
33    pub fn mirror_x(p: isize) -> Self {
34        Self {
35            arr: [[-1, 0, 2 * p], [0, 1, 0], [0, 0, 1]],
36        }
37    }
38
39    pub fn mirror_y(p: isize) -> Self {
40        Self {
41            arr: [[1, 0, 0], [0, -1, 2 * p], [0, 0, 1]],
42        }
43    }
44
45    pub fn dot(&self, other: &Self) -> Self {
46        let mut arr = [[0, 0, 0], [0, 0, 0], [0, 0, 0]];
47        for i in 0..3 {
48            for j in 0..3 {
49                for k in 0..3 {
50                    arr[i][j] += self.arr[i][k] * other.arr[k][j];
51                }
52            }
53        }
54        Self { arr }
55    }
56
57    pub fn apply(&self, vec: (isize, isize)) -> (isize, isize) {
58        (
59            self.arr[0][0] * vec.0 + self.arr[0][1] * vec.1 + self.arr[0][2],
60            self.arr[1][0] * vec.0 + self.arr[1][1] * vec.1 + self.arr[1][2],
61        )
62    }
63}
cp_library_rs/algebraic_structure/affine2d.rs

cp_library_rs/algebraic_structure/
affine2d.rs
