​

function setup() {

  createCanvas(800, 800);

}

​

​

function draw() {

  background(mouseY/2);

  var cols = width / grid;

  var rows = height / grid;

  for (var x = 1; x < cols; x++) {

    for (var y = 1; y < rows; y++){

      var ellipse_x = x * grid;

      var ellipse_y = y * grid;

      ellipse(ellipse_x, ellipse_y, grid, grid);

        fill(20, 50, 230);

    }

  }

}