let height = 500

let margin = 50

​

let numRows = 4

let numCols = 4

​

let squareLength = (width -2 * margin) / numCols

let maxShift = squareLength / 2

​

function setup() {

  createCanvas(400, 400);

  frameRate(1);

}

​

function draw() {

  fill('white');

  stroke('blue');

  for (let row = 0; row < numRows; row += 1) {

    for (let num = 0; num < 10; num++) {

      drawRow(row);

    }

  }

}

​

​

function drawRow(row) {

  for (let column = 0; column < numCols; column += 1) {

    let x = margin + column*squareLength + random(maxShift);

    let y = margin + row*squareLength + random(maxShift);

    if (random(20) < 10) {

      maxShift = maxShift;

    } else {

      maxShift = maxShift * -1;

    }

    textSize(72);

    text("&", x, y);

    //rect(x,y, squareLength, squareLength);

  }

}