rust-simd-noise

Super fast SIMD noise library for Rust. Currently in beta. PRs welcome!

Features

• SSE2, SSE41, and AVX2 instruction sets, along with non SIMD fallback
• AVX2 version also leverages FMA3
• Runtime detection picks the best available instruction set
• Simplex noise, fractal brownian motion, and turbulence
• 2d and 3d

Benchmarks

Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz Single Threaded

2D 1000x1000 FBM Noise, 3 Octaves

• scalar_2d ... bench: 74,207,703 ns/iter (+/- 2,184,952)
• sse2_2d ... bench: 23,863,725 ns/iter (+/- 746,331)
• sse41_2d ... bench: 22,440,765 ns/iter (+/- 995,336)
• avx2_2d ... bench: 12,022,253 ns/iter (+/- 508,793)

3D 100x100x100 FBM Noise, 3 Octaves

• scalar_3d ... bench: 102,543,499 ns/iter (+/- 3,310,472)
• sse2_3d ... bench: 39,991,825 ns/iter (+/- 1,043,332)
• sse41_3d ... bench: 38,852,436 ns/iter (+/- 1,350,831)
• avx2_3d ... bench: 23,231,237 ns/iter (+/- 777,420)

Todo

• AVX512 support
• ARM NEON support
• Voroni, Cell, and other noise types

Usage Notes

By default the Rust compiler will not target AVX2 and SSE41 instructions even if your machine supports them, you have to specify the target-cpu in RUSTFLAGS when building your project. For example you can add this to your .cargo/config file

[build]
rustflags = ["-C","target-cpu=native"]

Get a block of noise with runtime SIMD detection

The library will, at runtime, pick the fastest available options between SSE2, SSE41, and AVX2

use simdnoise::*;

// A struct to set up noise parameters
let fractal_settings = simdnoise::FractalSettings {
      freq: 0.04,
      lacunarity: 0.5,
      gain: 2.0,
      octaves: 3,
      noise_type: simdnoise::NoiseType::FBM,
}; 

// Get a block of 2d 800x600 noise, with no scaling of resulting values
// min and max values are returned so you can apply your own scaling
let (an_f32_vec,min,max) = simdnoise::get_2d_noise(0.0, 800, 0.0, 600, fractal_settings);

// Get a block of 200x200x200 3d noise
let (an_f32_vec,min,max) = simdnoise::get_3d_noise(0.0, 200, 0.0, 200,0.0, 200, fractal_settings);

// Get a block of noise scaled between -1 and 1
let an_f32_vec = simdnoise::get_2d_scaled_noise(0.0, 800, 0.0, 600, fractal_settings,-1.0,1.0);

Call noise functions directly

Sometimes you need something other than a block, like the points on the surface of a sphere. Sometimes you may want to use SSE41 even with AVX2 is available

// get a block of 100x100 sse41 noise, skip runtime detection
let (noise,min,max) = simdnoise::sse41::get_2d_noise(0.0,100,0.0,100,fractal_settings);

// send your own SIMD x,y values to the noise functions directly
unsafe {
  // sse2 simplex noise
  let x = _mm_set1_ps(5.0);
  let y = _mm_set1_ps(10.0);
  let f : __m128 = simdnoise::sse2::simplex_2d(x,y);
  
  // avx2 turbulence
  let x = _mm256_set1_ps(5.0);
  let y = _mm256_set1_ps(10.0);
  let freq = _mm_256_set1_ps(1.0);
  let lacunarity = _mm256_set1_ps(0.5);
  let gain = _mm256_set1_ps(2.0);
  let octaves = 3;
  let f_turbulence : __m256 = simdnoise::avx2::turbulence_2d(x,y,freq,lacunarity,gain,octaves);
    
}