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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
use math::{Point2, Point3, Point4};
use noise_fns::NoiseFn;
#[derive(Clone, Copy, Debug)]
pub struct Checkerboard {
pub size: usize,
_dummy: (),
}
impl Checkerboard {
const DEFAULT_SIZE: usize = 0;
pub fn new() -> Self {
Self {
size: 1 << Self::DEFAULT_SIZE,
_dummy: (),
}
}
pub fn set_size(self, size: usize) -> Self {
Self {
size: 1 << size,
..self
}
}
}
impl Default for Checkerboard {
fn default() -> Self {
Self::new()
}
}
impl NoiseFn<Point2<f64>> for Checkerboard {
fn get(&self, point: Point2<f64>) -> f64 {
calculate_checkerboard(&point, self.size)
}
}
impl NoiseFn<Point3<f64>> for Checkerboard {
fn get(&self, point: Point3<f64>) -> f64 {
calculate_checkerboard(&point, self.size)
}
}
impl NoiseFn<Point4<f64>> for Checkerboard {
fn get(&self, point: Point4<f64>) -> f64 {
calculate_checkerboard(&point, self.size)
}
}
fn calculate_checkerboard(point: &[f64], size: usize) -> f64 {
let result = point
.iter()
.map(|&a| a.floor() as usize)
.fold(0, |a, b| (a & size) ^ (b & size));
if result > 0 {
-1.0
} else {
1.0
}
}