createCanvas(400, 400);

  background(0);

  rectMode(RADIUS)

  half = width / 2

  colours = [ 

              [255,0,0],

              [0,255,0],

              [0,0,255],

              [255,255,0],

              [0,255,255],

              [255,0,255],

              [255,255,255],

              [128,128,128],

              [0,0,0],

              [0,0,0]

            ];

}

​

function squareCircle(radius) {

  return sqrt(sq(radius) / 2);

}

​

function draw() {

  drawStim(width, 0)

}

​

function drawStim(circleDia, cycle) {

  fill(colours[cycle % 10]) // circle

  print(cycle)

  if (cycle % 2 == 0) {

    circle(half, half, circleDia)

  }

  else {

    rect(half, half, squareCircle(circleDia / 2))

    circleDia = squareCircle(circleDia)

​

  }

  if (cycle < 8) {

    cycle = cycle + 1

    drawStim(circleDia, cycle)

  }

​

}