| // Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // Multi-language Perlin noise benchmark. |
| // See https://github.com/nsf/pnoise for timings and alternative implementations. |
| |
| #![feature(rand, core)] |
| |
| use std::f32::consts::PI; |
| use std::__rand::{Rng, thread_rng}; |
| |
| #[derive(Copy, Clone)] |
| struct Vec2 { |
| x: f32, |
| y: f32, |
| } |
| |
| fn lerp(a: f32, b: f32, v: f32) -> f32 { a * (1.0 - v) + b * v } |
| |
| fn smooth(v: f32) -> f32 { v * v * (3.0 - 2.0 * v) } |
| |
| fn random_gradient<R: Rng>(r: &mut R) -> Vec2 { |
| let v = PI * 2.0 * r.gen::<f32>(); |
| Vec2 { x: v.cos(), y: v.sin() } |
| } |
| |
| fn gradient(orig: Vec2, grad: Vec2, p: Vec2) -> f32 { |
| (p.x - orig.x) * grad.x + (p.y - orig.y) * grad.y |
| } |
| |
| struct Noise2DContext { |
| rgradients: [Vec2; 256], |
| permutations: [i32; 256], |
| } |
| |
| impl Noise2DContext { |
| fn new() -> Noise2DContext { |
| let mut rng = thread_rng(); |
| |
| let mut rgradients = [Vec2 { x: 0.0, y: 0.0 }; 256]; |
| for x in &mut rgradients[..] { |
| *x = random_gradient(&mut rng); |
| } |
| |
| let mut permutations = [0; 256]; |
| for (i, x) in permutations.iter_mut().enumerate() { |
| *x = i as i32; |
| } |
| rng.shuffle(&mut permutations); |
| |
| Noise2DContext { rgradients: rgradients, permutations: permutations } |
| } |
| |
| fn get_gradient(&self, x: i32, y: i32) -> Vec2 { |
| let idx = self.permutations[(x & 255) as usize] + |
| self.permutations[(y & 255) as usize]; |
| self.rgradients[(idx & 255) as usize] |
| } |
| |
| fn get_gradients(&self, x: f32, y: f32) -> ([Vec2; 4], [Vec2; 4]) { |
| let x0f = x.floor(); |
| let y0f = y.floor(); |
| let x1f = x0f + 1.0; |
| let y1f = y0f + 1.0; |
| |
| let x0 = x0f as i32; |
| let y0 = y0f as i32; |
| let x1 = x0 + 1; |
| let y1 = y0 + 1; |
| |
| ([self.get_gradient(x0, y0), self.get_gradient(x1, y0), |
| self.get_gradient(x0, y1), self.get_gradient(x1, y1)], |
| [Vec2 { x: x0f, y: y0f }, Vec2 { x: x1f, y: y0f }, |
| Vec2 { x: x0f, y: y1f }, Vec2 { x: x1f, y: y1f }]) |
| } |
| |
| fn get(&self, x: f32, y: f32) -> f32 { |
| let p = Vec2 {x: x, y: y}; |
| let (gradients, origins) = self.get_gradients(x, y); |
| |
| let v0 = gradient(origins[0], gradients[0], p); |
| let v1 = gradient(origins[1], gradients[1], p); |
| let v2 = gradient(origins[2], gradients[2], p); |
| let v3 = gradient(origins[3], gradients[3], p); |
| |
| let fx = smooth(x - origins[0].x); |
| let vx0 = lerp(v0, v1, fx); |
| let vx1 = lerp(v2, v3, fx); |
| let fy = smooth(y - origins[0].y); |
| |
| lerp(vx0, vx1, fy) |
| } |
| } |
| |
| fn main() { |
| let symbols = [' ', '░', '▒', '▓', '█', '█']; |
| let mut pixels = Box::new([0f32; 256*256]); |
| let n2d = Box::new(Noise2DContext::new()); |
| |
| for _ in 0..100 { |
| for y in 0..256 { |
| for x in 0..256 { |
| let v = n2d.get(x as f32 * 0.1, y as f32 * 0.1); |
| pixels[y*256+x] = v * 0.5 + 0.5; |
| } |
| } |
| } |
| |
| for y in 0..256 { |
| for x in 0..256 { |
| let idx = (pixels[y*256+x] / 0.2) as usize; |
| print!("{}", symbols[idx]); |
| } |
| print!("\n"); |
| } |
| } |