void setup () {
  noLoop();
  size (500, 500);
}
void mondrian (int x0, int y0, int x1, int y1, int level) {
  int d = int(random(x0, x1));
  int f =  int(random (y0, y1 ));

  if (level == 0) {
    return;
  } else {

    rectMode (CORNERS);

    fill( random (0, 255), random (0, 255), random (0, 255));
    rect (x0, y0, d, f);

    fill( random (0, 255), random (0, 255), random (0, 255));
    rect (d, y0, x1, f);

     fill( random (0, 255), random (0, 255), random (0, 255));
    rect (x0, f, d, y1);

     fill( random (0, 255), random (0, 255), random (0, 255));
    rect (d, f, x1, y1);

    mondrian(x0, y0, d, f, level-1);//topleft rectangle
    mondrian(d, y0, x1, f, level-1);//topright rectangle
    mondrian(x0, f, d, y1, level-1);//bottomleft rectangle
    mondrian (d, f, x1, y1, level-1);//bottomright rectangle
  }
}

void draw () {

  int level=3; // number of times the mondrian will recur
  int x0 = 0;
  int y0 = 0;
  int x1 = width;
  int y1 = height;

  mondrian(x0, y0, x1, y1, level);
}