Bonsaï.js pie chart

bonsaipiechart.js

var slices = [
  {value: 100, color: "red"},
  {value: 33, color: "green"},
  {value: 41, color: "blue"},
  {value: 103, color: "yellow"},
  {value: 145, color: "orange"},
];

var origin = {x: 200, y: 200},
    radius = 100,
    srtokeWidth = radius / 20;
 
var sum = slices.reduce(function(memo, slice) {
  memo += slice.value;
  return memo;
}, 0);
 
var currentSum = 0;
slices.forEach(function(slice) {
  var path = new Path();
  var percent = slice.value / sum;
  
  path.moveTo(origin.x, origin.y);
  path.arc(
    origin.x, origin.y,
    radius,
    currentSum * Math.PI * 2,
    (percent + currentSum) * Math.PI * 2,
    false
  );
  path.lineTo(origin.x, origin.y);
  
  path.stroke("#222", srtokeWidth).fill(slice.color).addTo(stage);
  
  currentSum += percent;
});