var d

var cx

var cy

​

var points

var connectPoints

​

var slider

var showCircle

var showTrace

var showShape

var showDriver

var speed

​

let paper

​

function preload(){

  paper = loadImage("background.jpg")

}

​

function setup() {

​

  var canvas = createCanvas(windowWidth, windowHeight - 100)

  canvas.parent("canvas")

​

  slider = createSlider(2, 30, 2)

  slider.parent("slider")

​

  showCircle = createCheckbox("Show Circle:", false)

  showCircle.parent("showCircle")

​

  showTrace = createCheckbox("Show Traces:", false)

  showTrace.parent("showTrace")

​

  showShape = createCheckbox("Connect Points:", false)

  showShape.parent("connectPoints")

  showDriver = createCheckbox("Show Driver Point:", false)

  showDriver.parent("showDriver")

​

  speed = createSlider(0, 0.1, 0.05, 0.001)

  speed.parent("speed")

​

  d = 0.95 * min(height,width)

  cx = width / 2

  cy = height / 2

}

​

function draw() {

  translate(cx, cy)

  //background(200, 144, 111)

  background(paper)

​

  points = slider.value()

  connectPoints = showShape.checked()

​

  if(showDriver.checked())

    traceDriver()

  if (showCircle.checked())

    drawCircle()

​

  if (connectPoints)

    beginShape()

​

  if (showTrace.checked())

    drawTrack()

​

  for (var i = 0; i < points; i++) {

    var t = i * PI / points

    var r = d / 2 * cos(angle - t)

    drawPoint(r, t)

  }

​

  if (connectPoints) {

    strokeWeight(1)

    noFill()

    stroke(255, 0, 0)

    endShape(CLOSE)

  }

  angle -= speed.value()

}

​

function drawPoint(r, t) {

  stroke(255, 255, 0)

  strokeWeight(10)

  var x = r * cos(t)

  var y = r * sin(t)

  point(x, y)

  if (connectPoints) {

    vertex(x, y)

  }

}

​

function drawTrack() {

  stroke(0, 0, 255)

  strokeWeight(1)

  for (var i = 0; i < points; i++) {

    var t = i * PI / points

    var x = d / 2 * cos(t)

    var y = d / 2 * sin(t)

    line(x, y, -x, -y)

  }

}

​

function drawCircle() {

  stroke(0)

  strokeWeight(1)

  noFill()

  ellipse(0, 0, d, d)

}

​

function traceDriver(){

  stroke(0,0,255)

  strokeWeight(10)

  point(d/2*cos(angle), d/2*sin(angle))

}