// Learning Processing
  // Daniel Shiffman
  // http://www.learningprocessing.com
  
  // Example 13-8: Recursion
  
  void setup() {
    size(200,200);
    smooth();
  }
  
  void draw() {
    background(255);
    stroke(0);
    noFill();
    drawCircle(width/2,height/2,100);
  }
  
  void drawCircle(float x, float y, float radius) {
    ellipse(x, y, radius, radius);
    if(radius > 2) {
      // drawCircle() calls itself twice, creating a branching effect. 
      // For every circle, a smaller circle is drawn to the left and right.
      drawCircle(x + radius/2, y, radius/2);
      drawCircle(x - radius/2, y, radius/2); 
    }
  }