https://bionboy.github.io/PerlinPlane/
https://github.com/josephg/noisejs
A speed-improved perlin and simplex noise algorithms for 2D.
Based on example code by Stefan Gustavson (stegu@itn.liu.se). Optimisations by Peter Eastman (peastman@drizzle.stanford.edu). Better rank ordering method by Stefan Gustavson in 2012. Converted to Javascript by Joseph Gentle.
Version 2012-03-09
This code was placed in the public domain by its original author, Stefan Gustavson. You may use it as you see fit, but attribution is appreciated.