conveyal/modeify

var raf = require('raf')

var body = document.body
var docEl = document.documentElement
var eve

/**
 * Expose `mouse`
 */

var mouse = module.exports = {}

/**
 * Run `updateLoop`
 */

updateloop()

/**
 * Save mouse move event
 */

window.addEventListener('mousemove', function (e) {
  eve = e || window.event
})

/**
 * Run update once per animation frame
 */

function updateloop () {
  raf(updateloop)
  update()
}

/**
 * Update mouse position
 */

function update () {
  if (!eve) return

  if (eve.pageX || eve.pageY) {
    mouse.x = eve.pageX
    mouse.y = eve.pageY
  } else {
    mouse.x = eve.clientX + body.scrollLeft + docEl.scrollLeft
    mouse.y = eve.clientY + body.scrollTop + docEl.scrollTop
  }

  eve = undefined
}