node-haxball/examples/plugins/replayRecorder.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 { OperationType, VariableType, ConnectionState, AllowFlags, Direction, CollisionFlags, CameraFollow, BackgroundType, GamePlayState, BanEntryType, Callback, Utils, Room, Replay, Query, Library, RoomConfig, Plugin, Renderer, Errors, Language, EventFactory, Impl } = API;

  Object.setPrototypeOf(this, Plugin.prototype);
  Plugin.call(this, "replayRecorder", true, { // "replayRecorder" is plugin's name, "true" means "activated just after initialization". Every plugin should have a unique name.
    version: "0.1",
    author: "abc",
    description: `This plugin allows the host to record replays.`,
    allowFlags: AllowFlags.CreateRoom // We allow this plugin to be activated on CreateRoom only.
  });
  
  this.defineVariable({
    name: "fileName",
    type: VariableType.String,
    value: "replay.hbr2",
    range: {
      min: 1,
      max: Infinity
    },
    description: "Name of the replay file to be saved."
  });

  this.defineVariable({
    name: "toggleRecording",
    type: VariableType.Void,
    value: ()=>{
      if (replay)
        endRecording(that.room.currentFrameNo);
      else
        startRecording(that.room.currentFrameNo);
    },
    description: "Starts or stops recording the replay file."
  });

  var that = this, replay = null, startFrameNo = -1;

  function startRecording(frameNo){
    if (replay)
      return;
    replay = new Replay.ReplayData();
    replay.roomData = that.room.state.copy();
    startFrameNo = frameNo;
  }

  function endRecording(frameNo){
    if (!replay)
      return;
    replay.totalFrames = frameNo-startFrameNo;
    replay.events.forEach((e)=>{
      e.frameNo -= startFrameNo;
    });
    var a = document.createElement("a");
    a.href = URL.createObjectURL(new Blob([Replay.writeAll(replay)], {
      type: "application/octet-stream"
    }));
    a.download = that.fileName;
    a.click();
    replay = null;
  }

  this.onOperationReceived = function(type, msg, globalFrameNo){
    if (!replay)
      return true;
    msg.frameNo = globalFrameNo;
    replay.events.push(msg);
    return true;
  }
};