                      display.width()/2-i, display.height()/2+i,
                      display.width()/2+i, display.height()/2+i, WHITE);
     display.display();
+    delay(1);
   }
 }
 

  for (int16_t i=0; i<display.height()/2; i+=2) {
    display.drawRect(i, i, display.width()-2*i, display.height()-2*i, WHITE);
    display.display();
  }
}


    // alternate colors
    display.fillRect(i, i, display.width()-i*2, display.height()-i*2, color%2);
    display.display();
    delay(1);
    color++;
  }
}
