​

var segmentCount = 360;

var radius = 300;

​

function setup() {

  createCanvas(800, 800);

  noStroke();

}

​

function draw() {

  colorMode(HSB, 360, width, height);

  background (360,0,height);

  var angleStep = 360 / segmentCount;

  beginShape(TRIANGLE_FAN);

  vertex(width / 2, height / 2);

  for (var angle = 0; angle <= 360; angle += angleStep) {

    var vx = width / 2 + cos(radians(angle)) * radius;

    var vy = height / 2 + sin(radians(angle)) * radius;

    vertex(vx, vy);

    fill(angle, mouseX, mouseY);

  }

  endShape();

}

​

function keyPressed() {

  if (key == 's' || key == 'S') saveCanvas();

  switch (key) {

    case '1':

      segmentCount = 360;

      break;

    case '2':

      segmentCount = 45;

      break;

    case '3':

      segmentCount = 24;

      break;

    case '4':

      segmentCount = 12;

      break;

    case '5':

      segmentCount = 6;

      break;

  }

}