noise-functions 0.8.5

A collection of fast and lightweight noise functions.
Documentation 
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
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160

use core::{cell::Cell, f32};
use std::{boxed::Box, thread_local};

use crate::{Constant, Noise, NoiseFn, OpenSimplex2, Perlin, Sample};

#[test]
fn translate() {
    const OFFSET: f32 = 10.0;

    thread_local! {
        static X: Cell<f32> = const { Cell::new(f32::NAN) };
        static Y: Cell<f32> = const { Cell::new(f32::NAN) };
        static Z: Cell<f32> = const { Cell::new(f32::NAN) };
        static W: Cell<f32> = const { Cell::new(f32::NAN) };
    }

    fn reset() {
        X.set(f32::NAN);
        Y.set(f32::NAN);
        Z.set(f32::NAN);
        W.set(f32::NAN);
    }

    fn assert(dim: usize) {
        for (i, value) in [&X, &Y, &Z, &W].into_iter().enumerate().take(dim) {
            assert_eq!(value.get(), OFFSET + (i + 1) as f32);
        }
    }

    fn noise2([x, y]: [f32; 2]) -> f32 {
        X.set(x);
        Y.set(y);
        x + y
    }

    fn noise3([x, y, z]: [f32; 3]) -> f32 {
        X.set(x);
        Y.set(y);
        Z.set(z);
        x + y + z
    }

    fn noise4([x, y, z, w]: [f32; 4]) -> f32 {
        X.set(x);
        Y.set(y);
        Z.set(z);
        W.set(w);
        x + y + z + w
    }

    reset();
    NoiseFn(noise2).translate_xy(1.0, 2.0).sample2([OFFSET; 2]);
    assert(2);

    reset();
    NoiseFn(noise3).translate_xyz(1.0, 2.0, 3.0).sample3([OFFSET; 3]);
    assert(3);

    reset();
    NoiseFn(noise4).translate_xyzw(1.0, 2.0, 3.0, 4.0).sample4([OFFSET; 4]);
    assert(4);
}

#[test]
fn translate_doesnt_crash() {
    Sample::<0>::sample_with_seed(&Constant(0.0).translate_x(0.0), [0.0; 0], 0);
    Sample::<0>::sample_with_seed(&Constant(0.0).translate_xy(0.0, 0.0), [0.0; 0], 0);
    Sample::<0>::sample_with_seed(&Constant(0.0).translate_xyz(0.0, 0.0, 0.0), [0.0; 0], 0);
    Sample::<0>::sample_with_seed(&Constant(0.0).translate_xyzw(0.0, 0.0, 0.0, 0.0), [0.0; 0], 0);

    Sample::<1>::sample_with_seed(&Constant(0.0).translate_x(0.0), [0.0; 1], 0);
    Sample::<1>::sample_with_seed(&Constant(0.0).translate_xy(0.0, 0.0), [0.0; 1], 0);
    Sample::<1>::sample_with_seed(&Constant(0.0).translate_xyz(0.0, 0.0, 0.0), [0.0; 1], 0);
    Sample::<1>::sample_with_seed(&Constant(0.0).translate_xyzw(0.0, 0.0, 0.0, 0.0), [0.0; 1], 0);

    Sample::<2>::sample_with_seed(&Constant(0.0).translate_x(0.0), [0.0; 2], 0);
    Sample::<2>::sample_with_seed(&Constant(0.0).translate_xy(0.0, 0.0), [0.0; 2], 0);
    Sample::<2>::sample_with_seed(&Constant(0.0).translate_xyz(0.0, 0.0, 0.0), [0.0; 2], 0);
    Sample::<2>::sample_with_seed(&Constant(0.0).translate_xyzw(0.0, 0.0, 0.0, 0.0), [0.0; 2], 0);

    Sample::<3>::sample_with_seed(&Constant(0.0).translate_x(0.0), [0.0; 3], 0);
    Sample::<3>::sample_with_seed(&Constant(0.0).translate_xy(0.0, 0.0), [0.0; 3], 0);
    Sample::<3>::sample_with_seed(&Constant(0.0).translate_xyz(0.0, 0.0, 0.0), [0.0; 3], 0);
    Sample::<3>::sample_with_seed(&Constant(0.0).translate_xyzw(0.0, 0.0, 0.0, 0.0), [0.0; 3], 0);

    Sample::<4>::sample_with_seed(&Constant(0.0).translate_x(0.0), [0.0; 4], 0);
    Sample::<4>::sample_with_seed(&Constant(0.0).translate_xy(0.0, 0.0), [0.0; 4], 0);
    Sample::<4>::sample_with_seed(&Constant(0.0).translate_xyz(0.0, 0.0, 0.0), [0.0; 4], 0);
    Sample::<4>::sample_with_seed(&Constant(0.0).translate_xyzw(0.0, 0.0, 0.0, 0.0), [0.0; 4], 0);
}

/// This test is meant to run under Miri to check for UB
#[test]
#[cfg(feature = "nightly-simd")]
fn sound_when_out_of_bounds() {
    _ = crate::ValueCubic.sample3a(std::simd::f32x4::splat(f32::INFINITY));
    _ = crate::ValueCubic.sample3a(std::simd::f32x4::splat(i32::MAX as f32 * 10.0));
}

#[test]
fn clamp() {
    assert_eq!(Constant(0.0).clamp(1.0, 2.0).sample2([0.0; 2]), 1.0);
    assert_eq!(Constant(1.5).clamp(1.0, 2.0).sample2([0.0; 2]), 1.5);
    assert_eq!(Constant(3.0).clamp(1.0, 2.0).sample2([0.0; 2]), 2.0);
    assert!(Constant(f32::NAN).clamp(1.0, 2.0).sample2([0.0; 2]).is_nan());

    // these would panic if we used `f32::clamp`, but our clamp must not panic
    Constant(0.0).clamp(2.0, 1.0).sample2([0.0; 2]);
    assert_eq!(Constant(0.0).clamp(f32::NAN, f32::NAN).sample2([0.0; 2]), 0.0);
}

#[test]
fn modifiers_manual_ridged() {
    let base = OpenSimplex2;
    let a = base.ridged();
    let b = base.abs().mul(-2.0).add(1.0);
    assert_eq(a, b);
}

fn assert_eq<A, B>(a: A, b: B)
where
    A: Sample<2>,
    B: Sample<2>,
{
    assert_approx_eq(0.0, a, b);
}

fn assert_approx_eq<A, B>(epsilon: f32, a: A, b: B)
where
    A: Sample<2>,
    B: Sample<2>,
{
    let mut max_error = 0.0f32;

    for x in 0..100 {
        for y in 0..100 {
            let x = x as f32 * 1.34900342;
            let y = y as f32 * 0.93124235;
            let p = [x, y];
            let av = a.sample2(p);
            let bv = b.sample2(p);
            max_error = max_error.max((av - bv).abs());
        }
    }

    std::println!("max error: {max_error}");

    if max_error > epsilon {
        panic!("error too big!");
    }
}

#[test]
fn test_trait_object_noise() {
    let perlin_dyn: &dyn Sample<2> = &Perlin;
    let _value = (&perlin_dyn).sample2([1.0, 2.0]);

    let perlin_box_dyn: Box<dyn Sample<2>> = Box::new(Perlin);
    let _value = perlin_box_dyn.sample2([1.0, 2.0]);
}