node-haxball/examples/roomConfigs/method2/autoPlay_defensive.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, RoomConfig.prototype);
  RoomConfig.call(this, { // Every roomConfig should have a unique name.
    name: "autoPlay_defensive",
    version: "0.4",
    author: "abc",
    description: `This is an auto-playing bot that follows the ball if it is near enough, otherwise goes back and tries to be just in the midpoint of ball and his team's goal line; and kicks the ball whenever it is nearby without any direction checking. This bot uses real events and controls real players.`,
    allowFlags: AllowFlags.CreateRoom | AllowFlags.JoinRoom // We allow this roomConfig to be activated on both CreateRoom and JoinRoom.
  });

  // parameters are exported so that they can be edited outside this class.
  this.defineVariable({
    name: "minCoordAlignDelta",
    description: "Minimum delta value for coordinate alignment", 
    type: VariableType.Number,
    value: 0.5, 
    range: {
      min: 0,
      max: 10,
      step: 0.5
    }
  });

  this.defineVariable({
    name: "minKickDistance",
    description: "Minimum distance between ball and bot player for the bot player to start kicking the ball", 
    type: VariableType.Number,
    value: 8, 
    range: {
      min: 0,
      max: 15,
      step: 0.5
    }
  });

  this.defineVariable({
    name: "maxDistanceToFollowBallCoeff",
    description: "Coefficient of max distance between ball and player for the bot to follow ball; otherwise it goes back to defense.", 
    type: VariableType.Number,
    value: 0.2, 
    range: {
      min: 0,
      max: 1,
      step: 0.01
    }
  });

  var that = this;
 
  this.onGameTick = function(customData){

    // ensure extrapolation of the room state before calculating stuff.
    room.extrapolate();

    var { state, gameState, gameStateExt } = that.room;
    gameState = gameStateExt || gameState;
    
    var cp = state.players.filter((x)=>(x.id==_room.currentPlayerId))[0];
    // get the original data object of the current player
    var playerDisc = cp.disc;
    if (!playerDisc) // check or else error occurs after changing a player's team to spectators, if the player is not actually in the game, or the game is stopped.
      return;
    var teamId = cp.team.id; //, oppositeTeamId = 2 - cpTeamId;
    var goals = state.stadium.goals, ball = gameState.physicsState.discs[0];

    // get the coordinates of the ball
    var {x, y} = ball?.pos || {};

    // if ball is not reachable, do nothing.
    if (x==null || isNaN(x) || !isFinite(x) || y==null || isNaN(y) || !isFinite(y)) // check 
      return;

    var targetX, targetY, sqrDistBetweenBallAndPlayer = (x-playerDisc.pos.x) * (x-playerDisc.pos.x) + (y-playerDisc.pos.y) * (y-playerDisc.pos.y);
    var maxDistanceToFollowBall = that.maxDistanceToFollowBallCoeff * state.stadium.width;
    var b = false;

    if (sqrDistBetweenBallAndPlayer > ((playerDisc.radius + ball.radius + maxDistanceToFollowBall) * (playerDisc.radius + ball.radius + maxDistanceToFollowBall))){
      var myGoal = goals.filter((g)=>(g.team.id==teamId))[0]; //, opponentGoal = goals[oppositeTeamId - 1];
      if (!myGoal)
        return;
      var MPofMyGoalX = (myGoal.p0.x + myGoal.p1.x) / 2, MPofMyGoalY = (myGoal.p0.y + myGoal.p1.y) / 2;
      targetX = (x + MPofMyGoalX) / 2;
      targetY = (y + MPofMyGoalY) / 2;
    }
    else{
      targetX = x;
      targetY = y;
      b = true;
    }

    // calculate delta difference for both x and y axis.
    var deltaX = targetX - playerDisc.pos.x, deltaY = targetY - playerDisc.pos.y, dirX, dirY, kick;
    if (Math.abs(deltaX) < that.minCoordAlignDelta) // we can omit small delta.
      dirX = 0;
    else 
      dirX = Math.sign(deltaX); // direction is +1 or -1, depending on the delta difference

    if (Math.abs(deltaY) < that.minCoordAlignDelta) // we can omit small delta.
      dirY = 0;
    else
      dirY = Math.sign(deltaY); // direction is +1 or -1, depending on the delta difference

    // kick is true if the distance between ball and player is less than minKickDistance
    kick = (deltaX * deltaX + deltaY * deltaY < (playerDisc.radius + ball.radius + that.minKickDistance) * (playerDisc.radius + ball.radius + that.minKickDistance));

    // apply current keys
    room.setKeyState(Utils.keyState(dirX, dirY, kick));
  };
};