radians to heading vector

r2v.js

'use strict';

function d2r(d) {
  return d * Math.PI / 180;
}

function r2d(r) {
  return r * 180 / Math.PI;
}

// radians to heading vector
function r2v(r) {
  return {
    x: Math.sin(r),
    y: Math.cos(r)
  };
}

function v2r(v) {
  return Math.atan2(v.x, v.y);
}