let pathCanvas;

let doublePendulum;

​

function setup() {

  createCanvas(800, 800)

  pathCanvas = createGraphics(width, height)

  pathCanvas.colorMode(HSB, 1, 1, 1, 1)

  cx = width / 2

  cy = height * 0.4

  pathCanvas.translate(cx, cy)

  pathCanvas.background(0.5)

  doublePendulum = new DoublePendulum({g: 1})

}

​

function draw() {

  clear()

  imageMode(CORNER)

  image(pathCanvas, 0, 0, width, height)

  translate(cx, cy)

  doublePendulum.next()

  doublePendulum.draw()

  // pathCanvas.noStroke()

  pathCanvas.fill(1, 1, 1)

  pathCanvas.line(doublePendulum.x2, doublePendulum.y2, doublePendulum.x3, doublePendulum.y3)

}