var scene,
    camera,
    renderer,
    container,
    aspect,
    fov,
    plane,
    far,
    mousex,
    mousey,
    windowhalfx,
    windowhalfy,
    geometry,
    starstuff,
    materialoptions,
    stars;

init();
animate();

function init() {
  container = document.createelement(`div`);
  document.getelementbyid('star_video').appendchild(container);
  
  mousex = 0;
  mousey = 0;

  aspect = window.innerwidth / window.innerheight;
  fov = 40;
  plane = 1;
  far = 800;

  windowhalfx = window.innerwidth / 2;
  windowhalfy = window.innerheight / 2;

  camera = new three.perspectivecamera(
    fov,
    aspect,
    plane,
    far
  );

  camera.position.z = far / 2;

  scene = new three.scene({ antialias: true });
  scene.fog = new three.fogexp2(0x1b1b1b, 0.0001);

  starforge();

  renderer = new three.webglrenderer({ antialias: true, alpha: true });
  renderer.setpixelratio((window.devicepixelratio) ? window.devicepixelratio : 1);
  renderer.setsize(window.innerwidth, 685);
  renderer.autoclear = false;
  renderer.setclearcolor(0x000000, 0.0);
  container.appendchild(renderer.domelement);

  document.addeventlistener('mousemove', onmousemove, false);
}

function animate() {
  requestanimationframe(animate);
  render();
}

function render() {
  camera.position.x += (mousex - camera.position.x) * 0.005;
  camera.position.y += (-mousey - camera.position.y) * 0.005;
  camera.lookat(scene.position);
  renderer.render(scene, camera);
}

function starforge() {
  var amount = 45000;
  geometry = new three.spheregeometry(1000, 100, 50);

  materialoptions = {
    color: new three.color(0xffffff),
    size: 1.1,
    transparency: true,
    opacity: 0.6
  };

  starstuff = new three.pointsmaterial(materialoptions);


  for (var i = 0; i < amount; i++) {
    var item = new three.vector3();
    item.x = math.random() * 2000 - 1000;
    item.y = math.random() * 2000 - 1000;
    item.z = math.random() * 2000 - 1000;

    geometry.vertices.push(item);
  }

  stars = new three.pointcloud(geometry, starstuff);
  scene.add(stars);
}

function onmousemove(e) {
  mousex = e.clientx - windowhalfx;
  mousey = e.clienty - windowhalfy;
}