参考错误文档未定义节点js MMORPG

Question

我正在使用NodeJS和MongoDB编写在线多人游戏。我有文件app.js，index.html，entity.js和inventory.js。每次我开始运行我的服务器时都会收到错误引用错误：文档未定义，它引用了库存中的refreshRender（）以及我在实体中使用它的位置，所以这显然是这个函数的错误，但我无法弄清楚是什么。

app.js：

var mongojs = require("mongojs");

require('./entity');
require('./client/inventory');

//Connect to database
var db = mongojs('localhost:27017/myGame', ['users','progress']);
var express = require('express');
var app = express();
var serv = require('http').Server(app);

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

serv.listen(8080);
console.log("Server started.");

var SOCKET_LIST = {};


var isValidPassword = function(data,callBack){
    db.users.find({username:data.username,password:data.password}, function(err,res){
        if(res.length > 0)
            callBack(true);
        else
            callBack(false);
    })
};


//Test to see if username already exists]
var isUsernameTaken = function(data,callBack){
    db.users.find({username:data.username}, function(err,res){
        if(res.length > 0)
callBack(true);
        else
            callBack(false);
    })
};

//Add user
var addUser = function(data,callBack){
    db.users.insert({username:data.username,password:data.password}, function(err){
        callBack();
    })
};

var io = require('socket.io')(serv,{});
io.sockets.on('connection', function(socket){
    socket.id = Math.random();
    SOCKET_LIST[socket.id] = socket;

    socket.on('logIn',function(data){
        isValidPassword(data,function(res){
            if(res){
                Player.onConnect(socket, data.username);
                socket.emit('signInResponse',{success:true});
            } else {
                socket.emit('signInResponse',{success:false});
            }
        });
    });
    socket.on('signUp',function(data){
        isUsernameTaken(data,function(res){
            if(res){
                socket.emit('signUpResponse',{success:false});
            } else {
                addUser(data,function(){
                    socket.emit('signUpResponse',{success:true});
                });
            }
        });
    });

    socket.on('disconnect',function(){
        delete SOCKET_LIST[socket.id];
        Player.onDisconnect(socket);
    });

});

setInterval(function(){
    var packs = Entity.getFrameData();
    for(var i in SOCKET_LIST){
        var socket = SOCKET_LIST[i];
        socket.emit('init',packs.initPack);
        socket.emit('update',packs.updatePack);
        socket.emit('remove',packs.removePack);
    }

},1000/25);

的index.html：

<div id="signDiv">
    Username: <input id="signDiv-username" type="text"></input><br>
    Password: <input id="signDiv-password" type="password"></input>
    <button id="signDiv-logIn">Log in</button>
    <button id="signDiv-signUp">Sign up</button>
</div>


<div id="gameDiv" style="display:none;">
    <div id="game" style="position:absolute;width:500px;height:500px">
        <canvas id="ctx" width="500" height="500" style="position:absolute;border:1px solid #000000;"></canvas>
        <canvas id="ctx-ui" width="500" height="500" style="position:absolute;border:1px solid #000000;"></canvas>

        <div id="ui" style="position:absolute;width:500px;height:500px;">
            <button onclick="changeMap()" style="position:absolute;bottom:0px;left:0px">
                Change Map
            </button>

        </div>

    </div>

    <div id="belowGame" style="margin-top:520px">
        <div id="chat-text" style="width:500px;height:100px;overflow-y:scroll">
            <div>Hello!</div>
        </div>
        <div id="inventory"></div>

        <form id="chat-form">
            <input id="chat-input" type="text" style="width:500px"></input>
        </form>
    </div>
</div>

<script src="https://cdn.socket.io/socket.io-1.4.5.js"></script>
<script src="/client/inventory.js"></script>
<script>
var WIDTH = 500;
var HEIGHT = 500;
var socket = io();

    //log in and sign up for game
    var signDiv = document.getElementById('signDiv');
    var signDivUsername = document.getElementById('signDiv-username');
    var signDivLogIn = document.getElementById('signDiv-logIn');
    var signDivSignUp = document.getElementById('signDiv-signUp');
    var signDivPassword = document.getElementById('signDiv-password');

    signDivLogIn.onclick = function(){
      socket.emit('logIn', {username:signDivUsername.value, password:signDivPassword.value});
    };

    signDivSignUp.onclick = function(){
    socket.emit('signUp', {username:signDivUsername.value, password:signDivPassword.value});
    };

    socket.on('signInResponse', function(data){
       if(data.success){
           signDiv.style.display = 'none';
           gameDiv.style.display = 'inline-block';
       } else
           alert("Log in unsuccessful")
    });

    socket.on('signUpResponse', function(data){
        if(data.success){
            alert("Sing up successful")
        } else
            alert("Sign up unsuccessful")
    });

    //Game chat, get elements
    var chatText = document.getElementById('chat-text');
    var chatInput = document.getElementById('chat-input');
    var chatForm = document.getElementById('chat-form');

    //Socket on for chat
    socket.on('addToChat', function(data){
        chatText.innerHTML += '<div>' + data + '</div>';
    });

chatForm.onsubmit = function(e){
        e.preventDefault();
        if(chatInput.value[0] === '/')
            socket.emit('evalServer',chatInput.value.slice(1));
        else if (chatInput.value[0] === '@'){
            //@username,message
            socket.emit('sendPrivToServer', {
                username:chatInput.value.slice(1, chatInput.value.indexOf(',')),
                message:chatInput.value.slice(chatInput.value.indexOf(',')+1)
            })
        }
         else
             socket.emit('sendMsgToServer',chatInput.value);
        chatInput.value = '';
    };

//UI
        var changeMap = function(){
    socket.emit('changeMap');
    };

        var inventory = new Inventory(socket, false);
        socket.on('updateInventory', function(items){
           inventory.items = items;
           inventory.refreshRender();
        });

    //Game

    //Game images
    var Img = {};
    Img.player = new Image();
    Img.player.src = '/client/image/player.png';
    Img.bullet = new Image();
    Img.bullet.src = '/client/image/bullet.png';
    Img.map = {};
    Img.map['default'] = new Image();
    Img.map['default'].src = '/client/image/map.png';
    Img.map['second'] = new Image();
    Img.map['second'].src = '/client/image/rocks.png';

    var ctx = document.getElementById("ctx").getContext("2d");
    var ctxUi = document.getElementById("ctx-ui").getContext("2d");
    ctxUi.font = '30px Arial';

    var Player = function(initPack){
        var self = {};
        self.id = initPack.id;
        self.number = initPack.number;
        self.x = initPack.x;
        self.y = initPack.y;
        self.hp = initPack.hp;
        self.hpMax = initPack.hpMax;
        self.sheild = initPack.sheild;
        self.sheildMax = initPack.sheildMax;
        self.score = initPack.score;
        self.map = initPack.map;

        self.draw = function() {
            if(Player.list[selfId].map !== self.map)
                return;
            var x = self.x - Player.list[selfId].x + WIDTH/2;
            var y = self.y - Player.list[selfId].y + HEIGHT/2;

            var hpWidth = 30 * self.hp/self.hpMax;
            ctx.fillStyle = 'green';
            ctx.fillRect(x - hpWidth/2, y - 40, hpWidth, 4);

            var sheildWidth = 30 * self.sheild/self.sheildMax;
            ctx.fillStyle = 'purple';
            ctx.fillRect(x - sheildWidth/2, y - 40, sheildWidth, 4);

            var width = Img.player.width; //may need to be smaller
            var height = Img.player.height;

            ctx.drawImage(Img.player,
            0,0,Img.player.width,Img.player.height,
            x-width/2,y-height/2,width,height);

            //ctx.fillText(self.score, self.x, self.y-60);
        };

        Player.list[self.id] = self;
        return self;
    };
    Player.list= {};

    var Bullet = function(initPack){
        var self = {};
        self.id = initPack.id;
        self.x = initPack.x;
        self.y = initPack.y;
        self.map = initPack.map;

        self.draw = function () {
            if(Player.list[selfId].map !== self.map)
                return;
            var width = Img.bullet.width/2;
            var height = Img.bullet.height/2;

            var x = self.x - Player.list[selfId].x + WIDTH/2;
            var y = self.y - Player.list[selfId].y + HEIGHT/2;

            ctx.drawImage(Img.bullet,
            0,0,Img.bullet.width,Img.bullet.height,
            x-width/2,y-height/2,width,height);
        };

        Bullet.list[self.id] = self;
        return self;
    };
Bullet.list = {};

var selfId = null;

    //Initialisation package
socket.on('init', function(data){
    if(data.selfId)
        selfId = data.selfId;
   for(var i = 0 ; i < data.player.length; i++){
       new Player(data.player[i]);
   }
   for(var i = 0 ; i < data.bullet.length; i ++){
       new Bullet(data.bullet[i])
   }
});

    //Update package
socket.on('update', function(data){
    for(var i = 0 ; i < data.player.length; i++){
        var pack = data.player[i];
        var p = Player.list[pack.id];
        if(p){
            if(pack.x !== undefined)
                p.x = pack.x;
            if(pack.y !== undefined)
                p.y = pack.y;
            if(pack.hp !== undefined)
                p.hp = pack.hp;
            if(pack.score !== undefined)
                p.score = pack.score;
            if(pack.sheild !== undefined)
                p.sheild = pack.sheild;
            if(pack.map !== undefined)
                p.map = pack.map;
        }
    }
    for(var i = 0 ; i < data.bullet.length; i++){
        var pack = data.bullet[i];
        var b = Bullet.list[data.bullet[i].id];
        if(b){
            if(pack.x !== undefined)
                b.x = pack.x;
            if(pack.y !== undefined)
                b.y = pack.y;
        }
    }
});

    //Remove package
    socket.on('remove',function(data){
        for(var i = 0 ; i < data.player.length; i++){
            delete Player.list[data.player[i]];
        }
        for(var i = 0 ; i < data.bullet.length; i++){
            delete Bullet.list[data.bullet[i]];
        }
    });

    setInterval(function(){
        if(!selfId)
            return;
        ctx.clearRect(0,0,500,500);
        drawMap();
        drawScore();
        for(var i in Player.list)
            Player.list[i].draw();
        for(var i in Bullet.list)
            Bullet.list[i].draw();
    },40);

    var drawMap = function () {
        var player = Player.list[selfId];
        var x = player.x;
        var y = player.y;
      ctx.drawImage(Img.map[player.map],x,y);
    };

    var drawScore = function () {
        if(lastScore === Player.list[selfId].score)
            return;
        lastScore = Player.list[selfId].score;
        ctxUi.clearRect(0,0,500,500);
        ctxUi.fillStyle = 'red';
        ctxUi.fillText(Player.list[selfId].score,0,40);
    };
    var lastScore = null;

    document.onkeydown = function(event){
        if(event.keyCode === 68)    //d
            socket.emit('keyPress',{inputId:'right',state:true});
        else if(event.keyCode === 83)   //s
            socket.emit('keyPress',{inputId:'down',state:true});
        else if(event.keyCode === 65) //a
            socket.emit('keyPress',{inputId:'left',state:true});
        else if(event.keyCode === 87) // w
            socket.emit('keyPress',{inputId:'up',state:true});

    };
    document.onkeyup = function(event){
        if(event.keyCode === 68)    //d
            socket.emit('keyPress',{inputId:'right',state:false});
        else if(event.keyCode === 83)   //s
            socket.emit('keyPress',{inputId:'down',state:false});
        else if(event.keyCode === 65) //a
            socket.emit('keyPress',{inputId:'left',state:false});
        else if(event.keyCode === 87) // w
            socket.emit('keyPress',{inputId:'up',state:false});
    };

    document.onmousedown = function(event){
        socket.emit('keyPress', {inputId:'shoot', state:true});
    };
    document.onmouseup = function (event){
        socket.emit('keyPress', {inputId:'shoot', state:false});
    };
    document.onmousemove = function(event){
      var x = -250 + event.clientX - 8;
      var y = -250 + event.clientY -8;
      var angle = Math.atan2(y,x)/Math.PI*180;
      socket.emit('keyPress', {inputId:'mouseAngle', state:angle});
    };

    document.oncontextmenu = function(event){
      event.preventDefault();
    };

</script>

inventory.js：

Inventory = function(items, socket, server){
    var self = {
        items:items, //{id:"itemId",amount:1}
        socket:socket,
        server:server
    }

    self.refreshRender = function(){
        //server
        if(self.server){
            self.socket.emit('updateInventory',self.items);
            return;
        }

        self.addItem = function(id,amount){
        for(var i = 0 ; i < self.items.length; i++){
            if(self.items[i].id === id){
                self.items[i].amount += amount;
                self.refreshRender();
                return;
            }
        }
        self.items.push({id:id,amount:amount});
        self.refreshRender();
    }
    self.removeItem = function(id,amount){
        for(var i = 0 ; i < self.items.length; i++){
            if(self.items[i].id === id){
                self.items[i].amount -= amount;
                if(self.items[i].amount <= 0)
                    self.items.splice(i,1);
                self.refreshRender();
                return;
            }
        }
    }
    self.hasItem = function(id,amount){
        for(var i = 0 ; i < self.items.length; i++){
            if(self.items[i].id === id){
                return self.items[i].amount >= amount;
            }
        }
        return false;
    }

        var inventory = document.getElementById("inventory");
        inventory.innerHTML = "";
        var addBtn = function(data) {
            let item = Item.list[data.id];
            let button = document.createElement('button');
            button.onclick = function(){
                self.socket.emit("useItem", item.id);
            }
            button.innerText = item.name + " x" + data.amount;
            inventory.appendChild(button);
        }
        for(var i = 0 ; i < self.items.length; i++){
            addBtn(self.items[i]);
        }
        if(self.server){}
        self.socket.on("useItem", function(itemId){
            if (!self.hasItem(itemId, 1)){
                console.log("You dont have the item");
                return;
            }
            let item = Item.list[itemId];
            item.event(Player.list[self.socket.id]);
        })
    }

    return self;
}


Item = function(id,name,event){
    var self = {
        id:id,
        name:name,
        event:event,
    }
    Item.list[self.id] = self;
    return self;
}
Item.list = {};

Item("potion","Potion",function(player){
    player.sheild = 10;
    player.inventory.removeItem("potion",1);
});

Item("newGun", "New Gun", function(player){
    player.inventory.removeItem("newGun", 1);
    player.inventory.addItem("newAttack", 1);
})

Item("newAttack","New Attack",function(player){
    for(var i = 0; i < 360; i++)
        player.shootBullet(i);
});

entity.js：

var initPack = {player:[],bullet:[]};
var removePack = {player:[],bullet:[]};

Entity = function(param){
    var self = {
        x:250,
        y:250,
        spdX:0,
        spdY:0,
        id:"",
        map:'default'
    };
    if(param){
        if(param.x)
            self.x = param.x;
        if(param.y)
            self.y = param.y;
        if(param.map)
            self.map = param.map;
        if(param.id)
            self.id = param.id;
    }
    self.update = function(){
        self.updatePosition();
    };
    self.updatePosition = function(){
        self.x += self.spdX;
        self.y += self.spdY;
    };
    self.getDistance = function(pt){
        return Math.sqrt(Math.pow(self.x-pt.x,2) + Math.pow(self.y-pt.y,2));
    };
    return self;
};

Entity.getFrameData = function () {
    var pack = {
        initPack:{
            player:initPack.player,
            bullet:initPack.bullet
        },
        removePack:{
            player:removePack.player,
            bullet:removePack.bullet
        },
        updatePack:{
            player:Player.update(),
            bullet:Bullet.update(),
        }
    };
    initPack.player = [];
    initPack.bullet = [];
    removePack.player = [];
    removePack.bullet = [];
    return pack;
};

 Player = function(param){
    var self = Entity(param);
    self.number = "" + Math.floor(10 * Math.random());
    self.username = param.username;
    self.pressingRight = false;
    self.pressingLeft = false;
    self.pressingUp = false;
    self.pressingDown = false;
    self.pressingShoot = false;
    self.mouseAngle = 0;
    self.maxSpd = 10;
    self.hp = 100;
    self.hpMax = 100;
    self.sheild = 0;
    self.sheildMax = 100;
    self.score = 0;
    self.inventory = new Inventory(param.socket, true);

    var super_update = self.update;
    self.update = function(){
        self.updateSpd();
        super_update();

        if(self.pressingShoot){
            self.shootBullet(self.mouseAngle);
        }
    };

    self.shootBullet = function(angle){
        if(Math.random() <0.1)
            self.inventory.addItem("potion",1);
        Bullet({
            parent:self.id,
            angle:angle,
            x:self.x,
            y:self.y,
            map:self.map
        })
    };

    self.updateSpd = function(){
        if(self.pressingRight)
            self.spdX = self.maxSpd;
        else if(self.pressingLeft)
            self.spdX = -self.maxSpd;
        else
            self.spdX = 0;

        if(self.pressingUp)
            self.spdY = -self.maxSpd;
        else if(self.pressingDown)
            self.spdY = self.maxSpd;
        else
            self.spdY = 0;
    };

    self.getInitPack = function(){
        return{
            id:self.id,
            x:self.x,
            y:self.y,
            number:self.number,
            hp:self.hp,
            hpMax:self.hpMax,
            shield:self.sheild,
            shieldMax:self.sheildMax,
            score:self.score,
            map:self.map
        }
    };

    self.getUpdatePack = function(){
        return{
            id:self.id,
            x:self.x,
            y:self.y,
            hp:self.hp,
            shield:self.sheild,
            score:self.score,
            map:self.map
        }
    };

    Player.list[self.id] = self;

    initPack.player.push(self.getInitPack());
    return self;
};
Player.list = {};
Player.onConnect = function(socket,username){
    var map = 'default';
    if(Math.random() < 0.2)
        map = 'second';
    var player = Player({
        username:username,
        id:socket.id,
        map:map,
        socket:socket
    });
    player.inventory.self.refreshRender();

    socket.on('keyPress',function(data){
        if(data.inputId === 'left')
            player.pressingLeft = data.state;
        else if(data.inputId === 'right')
            player.pressingRight = data.state;
        else if(data.inputId === 'up')
            player.pressingUp = data.state;
        else if(data.inputId === 'down')
            player.pressingDown = data.state;
        else if(data.inputId === 'shoot')
            player.pressingShoot = data.state;
        else if(data.inputId === 'mouseAngle')
            player.mouseAngle = data.state;
    });

    socket.on('changeMap',function(data){
        if(player.map === 'default')
            player.map = 'second';
        else
            player.map = 'default';
    });

    socket.on('sendMsgToServer', function(data){
        for(var i in SOCKET_LIST){
            SOCKET_LIST[i].emit('addToChat', player.username + ": " + data);
        }
    });

    socket.on('sendPrivToServer', function(data){
        var recipientSocket = null;
        for(var i in Player.list)
            if(Player.list[i].username === data.username)
                recipientSocket = SOCKET_LIST[i];
        if(recipientSocket === null){
            socket.emit('addToChat', 'Player not online');
        } else {
            recipientSocket.emit('addToChat', 'From ' + player.username + ': ' + data.message);
            socket.emit('addToChat', 'To ' + data.username + ': ' + data.message);
        }
    });

    socket.emit('init', {
        selfId:socket.id,
        player:Player.getAllInitPack(),
        bullet:Bullet.getAllInitPack()
    })
};

Player.getAllInitPack = function () {
    var players = [];
    for(var i in Player.list)
        players.push(Player.list[i].getInitPack());
    return players;
};

Player.onDisconnect = function(socket){
    delete Player.list[socket.id];
    removePack.player.push(socket.id);
};
Player.update = function(){
    var pack = [];
    for(var i in Player.list){
        var player = Player.list[i];
        player.update();
        pack.push(player.getUpdatePack());
    }
    return pack;
};

Bullet = function(param){
    var self = Entity(param);
    self.id = Math.random();
    self.angle = param.angle;
    self.spdX = Math.cos(param.angle/180*Math.PI) * 10;
    self.spdY = Math.sin(param.angle/180*Math.PI) * 10;
    self.parent = param.parent;
    self.timer = 0;
    self.toRemove = false;
    var super_update = self.update;
    self.update = function(){
        if(self.timer++ > 100)
            self.toRemove = true;
        super_update();

        for(var i in Player.list){
            var p = Player.list[i];
            if(self.map === p.map && self.getDistance(p) < 32 && self.parent !== p.id) {
                if (p.sheild > 0) {
                    p.sheild -= 1
                } else {
                    p.hp -= 1;

                    if (p.hp <= 0) {
                        var shooter = Player.list[self.parent];
                        if (shooter) {
                            shooter.score += 1;
                            p.hp = p.hpMax;
                            p.x = Math.random() * 500;
                            p.y = Math.random() * 500;
                        }
                    }
                    self.toRemove = true;
                }
            }
        }
    };

    self.getInitPack = function(){
        return{
            id:self.id,
            x:self.x,
            y:self.y,
            map:self.map
        }
    };

    self.getUpdatePack = function(){
        return{
            id:self.id,
            x:self.x,
            y:self.y,
        }
    };

    Bullet.list[self.id] = self;
    initPack.bullet.push(self.getInitPack());
    return self;
};
Bullet.list = {};

Bullet.update = function(){
    var pack = [];
    for(var i in Bullet.list) {
        var bullet = Bullet.list[i];
        bullet.update();
        if (bullet.toRemove){
            delete Bullet.list[i];
            removePack.bullet.push(bullet.id);
        }else
            pack.push(bullet.getUpdatePack());
    }
    return pack;
};

Bullet.getAllInitPack = function () {
    var bullets = [];
    for(var i in Bullet.list)
        bullets.push(Bullet.list[i].getInitPack());
    return bullets;
};