// Variance
int w = 240;
int h = 240;

// Set window
void setup() {
  surface.setResizable(true);
  surface.setSize(w, h);
  background(0,0,128);
}

void draw() {
  float bW = w/6;
  float bH = h/6;
  
  // Draw rectangle
  int i, j;
  for(j=1; j<=4; j++) {
    for(i=1; i<=4; i++) {
      rect(i*bW,  j*bH,  bW,  bW);
    }
  }
}