Конвертировать Paper.js в чистый JS код

var canvas = document.querySelector("#canvas"), 
  context = canvas.getContext("2d"), 
  target = { 
    x: 0.0, 
    y: 0.0 
  }, 
  mouse = { 
    x: 0.0, 
    y: 0.0 
  }, 
  chain = null; 
 
canvas.width = window.innerWidth; 
canvas.height = window.innerHeight; 
var Segment = function(size, head, tail) { 
  this.size = size; 
  this.head = head || { 
    x: 0.0, 
    y: 0.0 
  }; 
  this.tail = tail || { 
    x: this.head.x + size, 
    y: this.head.y + size 
  }; 
 
  this.update = function() { 
    var dx = this.head.x - this.tail.x, 
      dy = this.head.y - this.tail.y, 
      dist = Math.sqrt(dx * dx + dy * dy), 
      force = 0.5 - this.size / dist * 0.5, 
      strength = 0.998; 
    force *= 0.99; 
    var fx = force * dx, 
      fy = force * dy; 
    this.tail.x += fx * strength * 2.0; 
    this.tail.y += fy * strength * 2.0; 
    this.head.x -= fx * (1.0 - strength) * 2.0; 
    this.head.y -= fy * (1.0 - strength) * 2.0; 
  }; 
}; 
var Chain = function(size, interval) { 
  this.links = new Array(size); 
  this.update = function(target) { 
    var link = this.links[0]; 
    link.head.x = target.x; 
    link.head.y = target.y; 
    for (var i = 0, n = this.links.length; i < n; ++i) { 
      link = this.links[i]; 
      link.update(); 
    } 
  }; 
  var point = { 
    x: 0, 
    y: 0 
  }; 
  for (var i = 0, n = this.links.length; i < n; ++i) { 
    link = this.links[i] = new Segment(interval, point); 
    link.head.x = Math.random() * 500; 
    link.head.y = Math.random() * 500; 
    link.tail.x = Math.random() * 500; 
    link.tail.y = Math.random() * 500; 
    point = link.tail; 
  } 
}; 
 
function update() { 
  target.x += (mouse.x - target.x) * 0.1; 
  target.y += (mouse.y - target.y) * 0.1; 
  chain.update(target); 
} 
 
function draw() { 
  canvas.width = canvas.width, 
    link = chain.links[0], 
    p1 = link.head, 
    p2 = link.tail; 
 
  context.beginPath(); 
  context.moveTo(p1.x, p1.y); 
  context.strokeStyle = "red"; 
  context.lineWidth = 3; 
  context.lineJoin = "round"; 
  context.lineCap = "round"; 
 
  for (var i = 0, n = chain.links.length; i < n; ++i) { 
    link = chain.links[i]; 
    p1 = link.head; 
    p2 = link.tail; 
    context.lineTo(p1.x, p1.y); 
    context.lineTo(p2.x, p2.y); 
  } 
 
  context.stroke(); 
} 
 
function init() { 
  chain = new Chain(100, 2); 
 
  setInterval(function() { 
    update(); 
    draw(); 
  }, 5); 
} 
 
canvas.onmousemove = function(e) { 
  mouse.x = e.pageX; 
  mouse.y = e.pageY; 
}; 
 
function resize() { 
  canvas.width = document.body.clientWidth; 
  canvas.height = document.body.clientHeight; 
} 
 
window.onresize = resize; 
 
init();

* { 
  margin: 0; 
  padding: 0; 
} 
 
html, 
body { 
  overflow: hidden; 
  cursor: none; 
} 
 
canvas { 
  border: 1px solid; 
}

<canvas id="canvas"></canvas>