/* simple p5.js sketch - ds 2018-12-05 */

let w = 400;
let h = 400;
let nrow = 10;
let ncol = 10;
let offset = 5;

let sz = (w -(nrow+2) * offset) / nrow;

function setup() {
  createCanvas(w, h);
  noStroke();
  frameRate(6);
}
function draw() {
  background(126);
  for (i = 0; i < nrow; i++) {
    let x = sz*(i+0.5) + (i+1)*offset;
    for (j = 0; j < ncol; j++) {
      let y = sz*(j+0.5) + (j+1)*offset;
      if (mouseIsPressed  == true) {
        let r = 127+random(127);
        let c = color(r,20,20);
        fill(c);
      } else {
        fill(255);
      }
      ellipse(x, y, sz, sz );
    }

  }
}