// Simple recursion example

void setup ()
{
  size(400, 400);
  rectMode(CENTER);
}

void draw (){}

void mousePressed()
{
  drawBoxes(200);
}

// Recursive method: draw rect inside a rect
void drawBoxes(int size)
{
  println("Entering drawBoxes(" + size + ")...");
  if (size >= 50)
  {
    fill(random(256), random(256), random(256));
    rect(200, 200, size, size);
    drawBoxes(size - 50); // recursive call
  }
  println("Leaving drawBoxes(" + size + ")...");
}