node-haxball/examples/libraries/ticker.js

The most powerful and lightweight API that allows you to develop your original Haxball(www.haxball.com) host, client, and standalone applications both on node.js and browser environments and also includes every possible hack and functionality that you can

module.exports = function(API){
  const { Library, VariableType } = API;

  Object.setPrototypeOf(this, Library.prototype);
  Library.call(this, "ticker", {
    version: 0.1,
    author: "Dfg & abc",
    description: "A library to manage tick tasks in a single interval easily",
  });

  this.defineVariable({
    name: "tickRate",
    description: "The interval value in milliseconds", 
    type: VariableType.Integer,
    value: 10,
    range: {
      min: 0,
      max: Infinity,
      step: 1
    }
  });

  var that = this, tick = 0, tasks = null, interval = null;

  function Task(task, startTick, endTick=null, step=1, condition=()=>true){
    this.task = task;
    this.lastTick = startTick;
    this.endTick = endTick;
    this.step = step;
    this.condition = condition;
  }

  function startTicker(){
    if (interval)
      return;
    interval = setInterval(()=>{
      let toRemove = [];
      for (let i=0;i<tasks.length;i++){
        let task = tasks[i];
        if ((tick>=task.lastTick) && (task.endTick==null || tick<=task.endTick) && task.condition()){
          do{
            task.task();
            task.lastTick+=task.step;
          } while(tick>=task.lastTick && (task.endTick==null || tick<=task.endTick) && task.condition());
        }
        else if (tick>=task.endTick)
          toRemove.push(i);
      }
      for(let i=toRemove.length-1;i>=0;i--){
        let tR = toRemove[i];
        removeTickTaskByIndex(tR);
      }
      tick++;
    }, that.tickRate);
  }

  function stopTicker(){
    if (!interval)
      return;
    clearInterval(interval);
    interval = null;
  }

  function addTickTask(task){
    tasks.push(task);
    startTicker();
  }

  function runAfterTicks(func, tCount){
    addTickTask(new Task(func, tick+tCount, tick+tCount, 1));
  }

  function removeTickTaskByIndex(index){
    tasks.splice(index,1);
    if (tasks.length===0)
      stopTicker();
  }

  function removeTickTask(fn){
    var i = tasks.indexOf(fn);
    if (i>=0)
      removeTickTaskByIndex(i);
  }

  this.initialize = function(){
    tasks = [];
    tick = 0;
  };

  this.finalize = function(){
    stopTicker();
    tasks = null;
  };

  this.onVariableValueChange = function(addonObject, variableName, oldValue, newValue){
    if (addonObject==that && variableName=="tickRate" && interval!=null) {
      stopTicker();
      startTicker();
    }
  };

  Object.assign(this, {
    Task,
    runAfterTicks,
    start: startTicker,
    stop: stopTicker,
    addTask: addTickTask,
    removeTask: removeTickTask,
    currentTicks: ()=>tick
  });
};