Fast Simplex Noise

> Note: this project has been forked from joshforisha/fast-simplex-noise-js in an effort to bring a land generation plugin to the WebVoxel ecosystem.

A JavaScript implementation of the improved, faster Simplex algorithm outlined in Stefan Gustavson's Simplex noise demystified. Convenience functions have been added as well, in order to avoid needing to scale and handle the raw noise data directly.

Install

``bash
npm install @webvoxel/fast-simplex-noise
`

Example

`js
// Generate 2D noise in a 1024x768 grid, scaled to [0, 255]

const FastSimplexNoise = require('@webvoxel/fast-simplex-noise').default
const noiseGen = new FastSimplexNoise({ frequency: 0.01, max: 255, min: 0, octaves: 8 })

for (let x = 0; x < 1024; x++) for (let y = 0; y < 768; y++) {
grid[x][y] = noiseGen.scaled([x, y])
}
`

$3

You can pass a random number generator as an option (see constructor options below); specifically seedrandom is recommended when seeded values are desired.

`js
const seedrandom = require('seedrandom')

const rng = seedrandom('hello')
const noiseGen = new FastSimplexNoise({ random: rng })
`

API

$3

#### FastSimplexNoise(options?: Options = {})

Options contains:

- amplitude: number – The base amplitude (default: 1.0)
- frequency: number – The base frequency (default: 1.0)
- max: number – The maximum scaled value to return (effective default: 1.0)
- min: number – The minimum scaled value to return (effective default: -1.0)
- octaves: number – Integer; the number of octaves to sum for noise generation (default: 1)
- persistence: number – The persistence of amplitude per octave (default: 0.5)
- random: () => number – A function that generates random values between 0 and 1 (default: Math.random)

$3

#### cylindrical(circumference: number, coords: number[]): number

Get a scaled noise value (using options) for a 2D or 3D point at coords on the surface of a cylinder with circumference.

#### cylindrical2D(circumference: number, x: number, y: number): number

Specific cylindrical() call for a 2D point at (x, y).

#### cylindrical3D(circumference: number, x: number, y: number, z: number): number

Specific cylindrical() call for a 3D point at (x, y, z).

#### raw(coords: number[]): number

Get a noise value [-1, 1] at a 2D, 3D, or 4D point at coords.

#### raw2D(x: number, y: number): number

Specific raw() call for a 2D point at (x, y).

#### raw3D(x: number, y: number, z: number): number

Specific raw() call for a 3D point at (x, y, z).

#### raw4D(x: number, y: number, z: number, w: number): number

Specific raw() call for a 4D point at (x, y, z, w).

#### scaled(coords: number[]): number

Get a scaled noise value (using options) at a 2D, 3D, or 4D point at coords.

#### scaled2D(x: number, y: number): number

Specific scaled() call for a 2D point at (x, y).

#### scaled3D(x: number, y: number, z: number): number

Specific scaled() call for a 3D point at (x, y, z).

#### scaled4D(x: number, y: number, z: number, w: number): number

Specific scaled() call for a 4D point at (x, y, z, w).

#### spherical(circumference: number, point: number[]): number

Get a scaled noise value (using options) at a 2D or 3D point at coords on the surface of a sphere with circumference.

#### spherical2D(circumference: number, x: number, y: number): number

Specific spherical() call for a 2D point at (x, y).

#### spherical3D(circumference: number, x: number, y: number, z: number): number

Specific spherical() call for a 3D point at (x, y, z`).