tumult/lib/util/4d.js

A Javascript noise library

'use strict'

class Vec4 {
  constructor (x, y, z, t) {
    this.x = x
    this.y = y
    this.z = z
    this.t = t
  }

  dot (x, y, z, t) {
    return this.x * x + this.y * y + this.z * z + this.t * t
  }
}

const g4 = [
  new Vec4(0, 1, 1, 1), new Vec4(0, 1, 1, -1), new Vec4(0, 1, -1, 1), new Vec4(0, 1, -1, -1),
  new Vec4(0, -1, 1, 1), new Vec4(0, -1, 1, -1), new Vec4(0, -1, -1, 1), new Vec4(0, -1, -1, -1),
  new Vec4(1, 0, 1, 1), new Vec4(1, 0, 1, -1), new Vec4(1, 0, -1, 1), new Vec4(1, 0, -1, -1),
  new Vec4(-1, 0, 1, 1), new Vec4(-1, 0, 1, -1), new Vec4(-1, 0, -1, 1), new Vec4(-1, 0, -1, -1),
  new Vec4(1, 1, 0, 1), new Vec4(1, 1, 0, -1), new Vec4(1, -1, 0, 1), new Vec4(1, -1, 0, -1),
  new Vec4(-1, 1, 0, 1), new Vec4(-1, 1, 0, -1), new Vec4(-1, -1, 0, 1), new Vec4(-1, -1, 0, -1),
  new Vec4(1, 1, 1, 0), new Vec4(1, 1, -1, 0), new Vec4(1, -1, 1, 0), new Vec4(1, -1, -1, 0),
  new Vec4(-1, 1, 1, 0), new Vec4(-1, 1, -1, 0), new Vec4(-1, -1, 1, 0), new Vec4(-1, -1, -1, 0)
]

function grad4 (p, x, y, z, t) {
  const hash = p[x + p[y + p[z + p[t]]]] % g4.length
  return g4[hash]
}

module.exports = {
  grad4
}