JavaScript：游戏中代码的解释HexGl：opts。，hud，startDelay

Question

为了更好地理解javascript（我只是在学习），我开始查看各种在线游戏的代码。在这个游戏（HexGl）中，有一个startDelay，countDownDelay，opts。和hud。我似乎无法弄清楚他们的意思。我非常感谢有关这些变量以及它们如何使游戏受益的任何反馈！

游戏代码： https://github.com/BKcore/HexGL

这是一个来自Gameplay.js的片段：

bkcore.hexgl.Gameplay = function(opts)
{
  var self = this;
  this.startDelay = opts.hud == null ? 0 : 1000;
  this.countDownDelay = opts.hud == null ? 1000 : 1500;

  this.active = false;
  this.timer = new bkcore.Timer();
  this.modes = {
    'timeattack':null,
    'survival':null,
    'replay':null
};
  this.mode = opts.mode == undefined || !(opts.mode in this.modes) ?     "timeattack" : opts.mode;
  this.step = 0;

  this.hud = opts.hud;
  this.shipControls = opts.shipControls;
  this.cameraControls = opts.cameraControls;
  this.track = opts.track;
  this.analyser = opts.analyser;
  this.pixelRatio = opts.pixelRatio;

  this.previousCheckPoint = -1;

  this.results = {
    FINISH: 1,
    DESTROYED: 2,
    WRONGWAY: 3,
    REPLAY: 4,
    NONE: -1
};
  this.result = this.results.NONE;

  this.lap = 1;
  this.lapTimes = [];
  this.lapTimeElapsed = 0;
  this.maxLaps = 3;
  this.score = null;
  this.finishTime = null;
  this.onFinish = opts.onFinish == undefined ? function()  {console.log("FINISH");} : opts.onFinish;

  this.raceData = null;

  this.modes.timeattack = function()