node-haxball/examples/plugins/shake.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, "shake", true, {
    version: "0.1",
    author: "abc",
    description: `This plugin shakes your player in the direction that is always perpendicular to your current moving direction. Only players that use extrapolation will see the effects.`,
    allowFlags: AllowFlags.CreateRoom | AllowFlags.JoinRoom
  });

  var coeff = -1, dir = {
    x: 0, 
    y: 0
  };

  this.onGameTick = function(){
    var p = this.room.currentPlayer;
    if (!p.disc)
      return;
    var {x, y} = dir;
    if (x==0 && y==0){
      coeff = -1;
      return;
    }
    var {dirX, dirY, kick} = Utils.reverseKeyState(p.input);
    this.room.setKeyState(Utils.keyState(x-coeff*dirY, y+coeff*dirX, kick));
    coeff = -coeff;
  };

  this.onKeyDown = function({code}){
    switch(code){
      case "KeyA":
      case "ArrowLeft":
        if (dir.x==1)
          dir.x = 0;
        else
          dir.x = -1;
        break;
      case "KeyD":
      case "ArrowRight":
        if (dir.x==-1)
          dir.x = 0;
        else
          dir.x = 1;
        break;
      case "KeyW":
      case "ArrowUp":
        if (dir.y==1)
          dir.y = 0;
        else
          dir.y = -1;
        break;
      case "KeyS":
      case "ArrowDown":
        if (dir.y==-1)
          dir.y = 0;
        else
          dir.y = 1;
        break;
    }
  };

  this.onKeyUp = function({code}){
    switch(code){
      case "KeyA":
      case "ArrowLeft":
        if (dir.x==0)
          dir.x = 1;
        else
          dir.x = 0;
        break;
      case "KeyD":
      case "ArrowRight":
        if (dir.x==0)
          dir.x = -1;
        else
          dir.x = 0;
        break;
      case "KeyW":
      case "ArrowUp":
        if (dir.y==0)
          dir.y = 1;
        else
          dir.y = 0;
        break;
      case "KeyS":
      case "ArrowDown":
        if (dir.y==0)
          dir.y = -1;
        else
          dir.y = 0;
        break;
    }
  };
}