/* code from https://funprogramming.org/143-Using-PGraphics-as-layers-in-Processing.html */
PGraphics letters;
PGraphics squares;

void setup() {
  size(500, 500);

  letters = createGraphics(width, height);
  squares = createGraphics(width, height);
}
void draw() {
  background(255);

  letters.fill(#003300);
  letters.beginDraw();
  letters.text(int(random(10)), random(width), random(height));
  letters.endDraw();

  squares.beginDraw();
  squares.fill(#Ff3300);
  squares.rect(random(width), random(height), 40, 40);
  squares.endDraw();

  image(letters, 0, 0);
  image(squares, 0, 0);
}