1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Multi-language Perlin noise benchmark.
12 // See https://github.com/nsf/pnoise for timings and alternative implementations.
13 // ignore-lexer-test FIXME #15679
15 #![feature(rand, core)]
17 use std::f32::consts::PI;
19 use std::rand::{Rng, StdRng};
27 fn lerp(a: f32, b: f32, v: f32) -> f32 { a * (1.0 - v) + b * v }
29 fn smooth(v: f32) -> f32 { v * v * (3.0 - 2.0 * v) }
31 fn random_gradient<R: Rng>(r: &mut R) -> Vec2 {
32 let v = PI * 2.0 * r.gen::<f32>();
33 Vec2 { x: v.cos(), y: v.sin() }
36 fn gradient(orig: Vec2, grad: Vec2, p: Vec2) -> f32 {
37 (p.x - orig.x) * grad.x + (p.y - orig.y) * grad.y
40 struct Noise2DContext {
41 rgradients: [Vec2; 256],
42 permutations: [i32; 256],
46 fn new() -> Noise2DContext {
47 let mut rng = StdRng::new().unwrap();
49 let mut rgradients = [Vec2 { x: 0.0, y: 0.0 }; 256];
50 for x in &mut rgradients[..] {
51 *x = random_gradient(&mut rng);
54 let mut permutations = [0; 256];
55 for (i, x) in permutations.iter_mut().enumerate() {
58 rng.shuffle(&mut permutations);
60 Noise2DContext { rgradients: rgradients, permutations: permutations }
63 fn get_gradient(&self, x: i32, y: i32) -> Vec2 {
64 let idx = self.permutations[(x & 255) as usize] +
65 self.permutations[(y & 255) as usize];
66 self.rgradients[(idx & 255) as usize]
69 fn get_gradients(&self, x: f32, y: f32) -> ([Vec2; 4], [Vec2; 4]) {
80 ([self.get_gradient(x0, y0), self.get_gradient(x1, y0),
81 self.get_gradient(x0, y1), self.get_gradient(x1, y1)],
82 [Vec2 { x: x0f, y: y0f }, Vec2 { x: x1f, y: y0f },
83 Vec2 { x: x0f, y: y1f }, Vec2 { x: x1f, y: y1f }])
86 fn get(&self, x: f32, y: f32) -> f32 {
87 let p = Vec2 {x: x, y: y};
88 let (gradients, origins) = self.get_gradients(x, y);
90 let v0 = gradient(origins[0], gradients[0], p);
91 let v1 = gradient(origins[1], gradients[1], p);
92 let v2 = gradient(origins[2], gradients[2], p);
93 let v3 = gradient(origins[3], gradients[3], p);
95 let fx = smooth(x - origins[0].x);
96 let vx0 = lerp(v0, v1, fx);
97 let vx1 = lerp(v2, v3, fx);
98 let fy = smooth(y - origins[0].y);
105 let symbols = [' ', '░', '▒', '▓', '█', '█'];
106 let mut pixels = [0f32; 256*256];
107 let n2d = Noise2DContext::new();
112 let v = n2d.get(x as f32 * 0.1, y as f32 * 0.1);
113 pixels[y*256+x] = v * 0.5 + 0.5;
120 let idx = (pixels[y*256+x] / 0.2) as usize;
121 print!("{}", symbols[idx]);