// Daniel Shiffman

// http://natureofcode.com

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// Simple Recursion

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function setup() {

  createCanvas(640, 240);

}

​

function draw() {

  background(255);

  drawCircles(width / 2, height / 2, width / 2);

  noLoop();

}

​

// Very simple function that draws one circle

// and recursively calls itself

function drawCircles(x, y, r) {

  stroke(0);

  strokeWeight(2);

  circle(x, y, r * 2);

  // Exit condition, stop when radius is too small

  if (r > 4) {

    r *= 0.75;

    // Call the function inside the function! (recursion!)

    drawCircles(x, y, r);

  }

}

​