function setup() {
  createCanvas(800, 800);
  noFill();
}
Simple moire effect demonstration by moving, rotating
and scaling a shape of densely packed lines over
a background also consisting of densely packed lines.

MOUSE
mouseX              : overlay rotation or position x
mouseY              : overlay scaling

KEYS
1-2                 : switch draw mode
s                   : save png

CONTRIBUTED BY
[Niels Poldervaart](http://NielsPoldervaart.nl)