let cols; let rows; let size = 10;

let xoff = 0; let yoff = 0;

let inc = 0.1;

​

function setup() {

  createCanvas(400, 400);

  cols = width/size;

  rows = height/size;

  for (let i=0; i<cols; i++){

    noStroke();

    xoff += inc;

    colors[i] = [];

    yoff = 0;

    for (let j=0; j<rows; j++){

      colors[i][j] = noise(xoff, yoff)*255;

      yoff += inc;

    }

  }

}

​

function draw() {

  background(220);

  for (let i=0; i<cols; i++){

    for (let j=0; j<rows; j++){

      fill(colors[i][j]);

      rect(i*size, j*size, size, size);

    }

  }

}