git ssb

1
var GreatCircle = require('great-circle')
2
3
var pre = document.createElement('pre')
4
var speed = document.createElement('h1')
5
var position = document.createElement('h3')
6
document.body.appendChild(speed)
7
document.body.appendChild(position)
8
document.body.appendChild(pre)
9
10
function flatten (p) {
11
  var o = {}
12
  for(var k in p)
13
    if(p[k] && 'object' === typeof p[k])
14
      o[k] = flatten(p[k])
15
    else
16
      o[k] = p[k]
17
  return o
18
}
19
20
var DEGREE_SYMBOL = '\u00b0'
21
22
23
function decimalTudeToMinutes (tude) {
24
  return ~~tude.toString()+DEGREE_SYMBOL+Math.abs((tude - ~~(tude))*60).toPrecision(4)
25
}
26
27
var positions = []
28
29
pre.textContent = 'waiting for position...'
30
31
function round(r, n) {
32
  var f = Math.pow(10, n)
33
  return Math.round(r*f)/f
34
}
35
36
navigator.geolocation.watchPosition(function (e) {
37
  positions.push(flatten(e))
38
  //keep just one minute's worth of locations.
39
40
  while(positions.length && positions[0].timestamp < Date.now() - 60e3) // one minute
41
    positions.shift()
42
43
  var lat = e.coords.latitude, long = e.coords.longitude
44
  var movement = positions.map(function (_e) {
45
    var _lat = _e.coords.latitude, _long = _e.coords.longitude
46
    var time = e.timestamp - _e.timestamp
47
    return {
48
      distance: GreatCircle.distance(_lat, _long, lat, long, 'NM'),
49
      heading: GreatCircle.bearing(_lat, _long, lat, long),
50
      speed: GreatCircle.distance(_lat, _long, lat, long, 'NM') / (time / (1000*60*60)),
51
      time: (e.timestamp - _e.timestamp)/1000
52
    }
53
  })
54
55
  position.textContent = (
56
    decimalTudeToMinutes(e.coords.latitude)
57
    + ', ' +
58
    decimalTudeToMinutes(e.coords.longitude)
59
  )
60
61
  E = e
62
  var metersPerSecond = e.coords.speed || 0
63
  var metersPerHour = metersPerSecond*3600
64
  var metersPerNauticalMile = 1852.001
65
  var knots = metersPerHour/metersPerNauticalMile
66
  speed.textContent = round(knots, 2)
67
  pre.textContent = JSON.stringify(movement, null, 2)
68
}, function (err) {
69
  pre.textContent = JSON.stringify({error:err.code, message: err.message}, null, 2)
70
}, {
71
  enableHighAccuracy: true,
72
  timeout: 5000,
73
  maximumAge: 0
74
})
75
76