1//  MIT License. © Inigo Quilez, Munrocket
2//  noise2() is any noise here: Value, Perlin, Simplex, Worley
3//
4#define_import_path bevy_water::noise::fbm
5
6#import bevy_water::noise::vnoise::vnoise2d
7
8fn fbm(v2: vec2<f32>) -> f32 {
9  let m2 = mat2x2<f32>(vec2<f32>(0.8, 0.6), vec2<f32>(-0.6, 0.8));
10  var p = v2;
11  var f = 0.5000 * vnoise2d(p); p = m2 * p * 2.02;
12  f = f + 0.2500 * vnoise2d(p); p = m2 * p * 2.03;
13  f = f + 0.1250 * vnoise2d(p); p = m2 * p * 2.01;
14  f = f + 0.0625 * vnoise2d(p);
15  return f / 0.9375;
16}
17
18fn fbm_half(v2: vec2<f32>) -> f32 {
19  let m2 = mat2x2<f32>(vec2<f32>(0.8, 0.6), vec2<f32>(-0.6, 0.8));
20  var p = v2;
21  var f = 0.5000 * vnoise2d(p); p = m2 * p * 2.02;
22  f = f + 0.2500 * vnoise2d(p);
23  return f / 0.9375;
24}