mapbox-gl: updating line

<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8' />
    <title></title>
    <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
    <script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.12.0/mapbox-gl.js'></script>
    <link href='https://api.tiles.mapbox.com/mapbox-gl-js/v0.12.0/mapbox-gl.css' rel='stylesheet' />
    <style>
        body { margin:0; padding:0; }
        #map { position:absolute; top:0; bottom:0; width:100%; }
    </style>
</head>
<body>

<div id='map'></div>
<script>
mapboxgl.accessToken = 'pk.eyJ1IjoiZW5qYWxvdCIsImEiOiIzOTJmMjBiZmI2NGQ2ZjAzODhiMzhiOGI2MTI1YTk4YSJ9.sIOXXU3TPp5dLg_L3cUxhQ';
var map = new mapboxgl.Map({
    container: 'map',
    style: 'mapbox://styles/mapbox/streets-v8',
    center: [-122.486052, 37.830348],
    zoom: 15,
    pitch: 50
});

map.on('style.load', function () {
  var points = [
    [-122.48369693756104, 37.83381888486939],
    [-122.48348236083984, 37.83317489144141],
    
  ];
  var morepoints = [
    [-122.48339653015138, 37.83270036637107],
    [-122.48356819152832, 37.832056363179625],
    [-122.48404026031496, 37.83114119107971],
    [-122.48404026031496, 37.83049717427869],
    [-122.48348236083984, 37.829920943955045],
    [-122.48356819152832, 37.82954808664175],
    [-122.48507022857666, 37.82944639795659],
    [-122.48610019683838, 37.82880236636284],
    [-122.48695850372314, 37.82931081282506],
    [-122.48700141906738, 37.83080223556934],
    [-122.48751640319824, 37.83168351665737],
    [-122.48803138732912, 37.832158048267786],
    [-122.48888969421387, 37.83297152392784],
    [-122.48987674713133, 37.83263257682617],
    [-122.49043464660643, 37.832937629287755],
    [-122.49125003814696, 37.832429207817725],
    [-122.49163627624512, 37.832564787218985],
    [-122.49223709106445, 37.83337825839438],
    [-122.49378204345702, 37.83368330777276]
  ];
  
  var data = {
    "type": "Feature",
    "properties": {},
    "geometry": {
        "type": "LineString",
        "coordinates": points
    }
  }
  var source = new mapboxgl.GeoJSONSource({data: data})
  
  map.addSource("route", source);
  
  morepoints.forEach(function(p, i) {
    setTimeout(function() {
      points.push(p);
      source.setData(data)
    }, 1500 + i * 180)
  })
  setTimeout(function() {
    
  }, 1000)

map.addLayer({
    "id": "route",
    "type": "line",
    "source": "route",
    "layout": {
      "line-join": "round",
      "line-cap": "round"
    },
    "paint": {
      "line-color": "#888",
      "line-width": 8
    }
  });
});
  
  var scale = d3.scale.linear()
  .domain([0, 960])
  .range([0, 90])
  var container = map.getCanvasContainer()
  d3.select(container).on("mousemove", function() {
    var mouse = d3.mouse(this);
    console.log(mouse[0], scale(mouse[0]))
    map.setPitch(scale(mouse[0]))
  })
</script>

</body>
</html>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js

https://api.tiles.mapbox.com/mapbox-gl-js/v0.12.0/mapbox-gl.js