node-haxball/examples/plugins/CMD_modifyPlayerInput.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, "CMD_modifyPlayerInput", true, { // "modifyPlayerInput" 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 lets players modify other players' input key events.
    Key input value can be calculated as ([kick]*16+[right]*8+[left]*4+[up]*2+[down]*1) where [kick], [right], [left], [up], [down] are all 0(not pressed) or 1(pressed).
    Available commands: 
    - !input [id] [value]: Set the key input value for the player whose playerId=[id] as [value]. 0<=value<=31.`,
    allowFlags: AllowFlags.CreateRoom // We allow this plugin to be activated on CreateRoom only.
  });

  var staticInputs, permissionCtx, permissionIds = {}, that = this;

  this.initialize = function(){
    staticInputs = {};
    permissionCtx = that.room.librariesMap.permissions?.createContext("modifyPlayerInput");
    if (permissionCtx)
      permissionIds = {
        input: permissionCtx.addPermission("input")
      };
    that.room.librariesMap.commands?.add({
      name: "input",
      parameters: [{
        name: "playerId",
        type: VariableType.Integer,
        range: {
          min: 0
        }
      }, {
        name: "value",
        type: VariableType.Integer,
        range: {
          min: -1,
          max: 31,
        }
      }],
      minParameterCount: 2,
      helpText: "Lets you change a player's input. '-1' resets to default.",
      callback: ({playerId, value}, byId) => {
        if (!that.room.getPlayer(playerId))
          return;
        if (byId!=0 && !permissionCtx?.checkPlayerPermission(byId, permissionIds.input)){
          that.room.librariesMap.commands?.announcePermissionDenied(byId);
          return;
        }
        staticInputs[playerId] = value<0 ? null : value;  // store a static input value for this player
      }
    });
  };

  this.finalize = function(){
    that.room.librariesMap.commands?.remove("input");
    that.room.librariesMap.permissions?.removeContext(permissionCtx);
    staticInputs = null;
    permissionCtx = null;
    permissionIds = null;
  };

  this.onOperationReceived = function(type, msg, globalFrameNo, clientFrameNo, customData){
    var playerId = msg.byId;
    switch (type){
      case OperationType.SendInput: { // this event runs only when player presses/releases a key
        var input = staticInputs[playerId]; // get a static input value for the player who sent this event.
        if (input != null) // if it exists,
          msg.input = input; // set the event's input value to it.
        break;
      }
    }
    return true;
  };

  this.onPlayerLeave = function(playerObj, reason, isBanned, byId, customData){
    // get player's id
    var id = playerObj.id;

    // free extra memory allocated
    delete staticInputs[id];
  };
};