Pong/index.js

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);

app.get('/', function(req, res){
  res.sendFile(__dirname + '/index.html');
});

var sockets = [];
var gameState = 0;
var width, height;
var startinterval;

/** Game-Config **/
var cube_width = 50,
    cube_height = 200,
    speed = 7;

/** ########## **/
/** CONNECTION **/
/** ########## **/
io.on('connection', function(socket){
  var id = sockets.length + 1;
  if(sockets.length == 1)
    if(sockets[0].id == 2) id = 1;
  var clientkey = sockets.push(new Client(id, socket)) - 1;
  console.log('Client connected. ID=' + id);

  /** ######### **/
  /** HANDSHAKE **/
  /** ######### **/
  socket.emit('handshake', id, gameState, cube_width, cube_height, speed, function(w, h){ // Callback function for 1st Client to set screen size //
    sockets[clientkey].width = w;
    sockets[clientkey].height = h;
    if(sockets.length > 1 && gameState == 0) setUp(socket);
  });

if(gameState > 0) socket.emit('size', width, height);
  /** #### **/
  /** Ping **/
  /** ### **/
  socket.on('appping', function(fn){
    fn(Date.now());
  });

  /** #### **/
  /** Ballshoot **/
  /** ### **/
  socket.on('ballshoot', function(y){
    socket.broadcast.emit('shootball', y);
  });

  /** ################ **/
  /** Paddel V-Change **/
  /** ############## **/
  socket.on('vchange', function(pos, val, y){
    socket.broadcast.emit('changeV', pos, val, y);
  });

  /** ########## **/
  /** DISCONNECT **/
  /** ########## **/
  socket.on('disconnect', function(){
    var index;
    sockets.forEach(function(sock, ind){
      if (sock.socket == socket){
          index = ind;
          return;
      }
    });
    var oldid = sockets[index].id;
    sockets.splice(index, 1);
    console.log('Client disconnected. ID=' + (oldid+1));
    if(sockets.length == 1){
      sockets[0].socket.emit('test', 'player_left'); //TODO win-event
      console.log('Only one Player left. Sending win-event');
      // Debug Restart:
      gameState = 0;
      clearInterval(startinterval);
      broadcastGameState(socket);
      return;
    }
    else if(sockets.length == 0){
      console.log('All Players left. Reseting lobby...');
      gameState = 0;
      id = 0;
      return;
    }

    var key = 0;
    if(sockets[0].id == 1 || sockets[0].id == 2) key = 1;
    switch(oldid){
      case 1 : sockets[key].id = 1; sockets[key].socket.emit('handshake', 1); console.log('New Player 1 selected.'); setUp(); break;
      case 2 : sockets[key].id = 2; sockets[key].socket.emit('handshake', 2); console.log('New Player 2 selected.'); setUp(); break;
      default : console.log('Spectator left. Nothing need to select new Players.'); break;

    }
  });
});


http.listen(3000, function(){
  console.log('listening on *:3000');
});

function setUp(socket){
  gameState = 1;
  broadcastGameState(socket);
  console.log('Starting SetUp...');
  /** Select smalest screensize and set for all clients **/
  sockets.forEach(function(sock){
    broadcastGameState(socket);
    if(sock.id == 1)
      sockets.forEach(function(sock2){
        if(sock2.id == 2){
          if(sock.width < sock2.width)
            width = sock.width;
          else
            width = sock2.width;
          if(sock.height < sock2.height)
            height = sock.height;
          else
            height = sock2.height;
          }
      });
  });
  socket.emit('size', width, height);
  socket.broadcast.emit('size', width, height);
  var i = 5;
  startinterval = setInterval(function(){
    i--;
    socket.emit('countdown', i);
    socket.broadcast.emit('countdown', i);
    if(i == 0){
      clearInterval(startinterval);
      gameState = 2;
      broadcastGameState(socket);
      socket.emit('start');
      socket.broadcast.emit('start');
    }
  }, 1000);
}

function broadcastGameState(socket){
  socket.emit('gamestate', gameState);
  socket.broadcast.emit('gamestate', gameState);
}

function Client(id, socket){
  this.id = id;
  this.socket = socket;
  this.width = 0;
  this.height = 0;
}