javascript - html5/javascript 游戏在 ie8 中运行缓慢

Question

我们用 html/javascript 制作了一个游戏。不幸的是，这个项目有很多 secret ，所以我不能透露太多代码。

然而本质是它在所有浏览器上都运行得非常好，除了ie。通过使用 <meta http-equiv="X-UA-Compatible" content="IE=9">标签;现在唯一的问题是 ie8，游戏需要与之兼容。我知道它几乎没有集成 html5，但游戏确实可以运行，只是速度非常慢。

请记住，ie9 和 ie10 在使用该标记之前也非常慢。该游戏在某种意义上是先进的或任何东西。所以我想知道是否有人知道什么会导致此类问题？

我将尝试在此处放置一些经过混淆的代码，请记住这不是完整的代码，只是主循环:

    // Global constants:
var PLAYGROUND_WIDTH    = 1000;
var PLAYGROUND_HEIGHT    = 1000;
var REFRESH_RATE        = 30;

//Constants for the gameplay
var smallStarSpeed        = 1; //pixels per frame

var mediumStarSpeed       = 3; //pixels per frame

var bigStarSpeed          = 5; //pixels per frame

var percent = 1;

// --------------------------------------------------------------------
// --                      the main declaration:                     --
// --------------------------------------------------------------------

$(function(){
//Calculate playground width and height:
PLAYGROUND_WIDTH = $(window).width() - 20;
PLAYGROUND_HEIGHT = $(window).height() - 20;

//Calculate Layour for responsive Design.
//Calculate Area:


// Animations declaration: 
// The background:    

var DM = new DeckManager;
var IM = new ImageManager;

IM.Create("Image1");


//DEBUG: Loading images for demo, this should be done using the image manager in the actual game.
var background1 = new $.gameQuery.Animation({
    imageURL: "http://gamequeryjs.com/demos/3/background1.png"});
var background2 = new $.gameQuery.Animation({
    imageURL: "http://gamequeryjs.com/demos/3/background2.png"}); 
var background3 = new $.gameQuery.Animation({
    imageURL: "http://gamequeryjs.com/demos/3/background3.png"});
var background4 = new $.gameQuery.Animation({
    imageURL: "http://gamequeryjs.com/demos/3/background4.png"});
var background5 = new $.gameQuery.Animation({
    imageURL: "http://gamequeryjs.com/demos/3/background5.png"});
var background6 = new $.gameQuery.Animation({
    imageURL: "http://gamequeryjs.com/demos/3/background6.png"});



    var Face = new Array();
    IM.Load("image2");
    IM.Load("image3");
    IM.Load("image4");
            IM.Load("image5");


            var resizeTimer;

//Event to handle resizing
//This event should fire under any circimstance, except when safari is NOT maximized, and windows resolution is changed (WTF?)
$(window).resize(function () 
{
    clearTimeout(resizeTimer);
    resizeTimer = setTimeout(Resized, 100);
});

//Actual Resizing Event
function Resized() 
{
    //Your function goes here


    //Calculate playground width and height:
    PLAYGROUND_WIDTH = $(window).width() - 20;
    PLAYGROUND_HEIGHT = $(window).height() - 20;

    //Calculate Layout for responsive Design.
};


// Initialize the game:
$("#playground").playground({
    height: PLAYGROUND_HEIGHT, 
    width: PLAYGROUND_WIDTH, 
    keyTracker: true,
    mouseTracker: true});

// Initialize the background
$.playground()
    .addGroup("background", {width: PLAYGROUND_WIDTH, 
                             height: PLAYGROUND_HEIGHT})
    .addSprite("background1", {animation: background1, 
                               width: PLAYGROUND_WIDTH, 
                               height: PLAYGROUND_HEIGHT})  
    .addSprite("background2", {animation: background2,
                               width: PLAYGROUND_WIDTH, 
                               height: PLAYGROUND_HEIGHT, 
                               posx: PLAYGROUND_WIDTH})
    .addSprite("background3", {animation: background3, 
                               width: PLAYGROUND_WIDTH, 
                               height: PLAYGROUND_HEIGHT})
    .addSprite("background4", {animation: background4, 
                               width: PLAYGROUND_WIDTH, 
                               height: PLAYGROUND_HEIGHT, 
                               posx: PLAYGROUND_WIDTH})
    .addSprite("background5", {animation: background5, 
                               width: PLAYGROUND_WIDTH, 
                               height: PLAYGROUND_HEIGHT})
    .addSprite("background6", {animation: background6, 
                               width: PLAYGROUND_WIDTH, 
                               height: PLAYGROUND_HEIGHT, 
                               posx: PLAYGROUND_WIDTH})
    $("#background").addSound(bgmusic);
//Setup obects so they can be reached randomly
var Vals = new Array();
var Vals2 = new Array();
var Turned = 0;
var TurnedMax = 2;

//This will ensure that two cards of each are added to the deck
//This function will be handled by the imagemanager at later stages.
for (var i = 0; i < NumberOfCards; ++i)
{
    Vals[i] = Math.floor(i/2);
}

Vals2[0]=3;

DM.Create(Vals, Vals2, NumberOfCards, 1);

//Generate the actual object

    $.playground()
    .addGroup("object", {width: PLAYGROUND_WIDTH, 
                             height: PLAYGROUND_HEIGHT})

for (var i = 0; i < NumberOfCards+1; ++i)
{
    //Generate unique ID for the card
    var name = "object"+i;

    val = DM.Pushobject();

    //Add the actual card to the playground, we spawn them in a responsive awy based on the resolution of the game.
    $("#object").addSprite(name, {animation: IM.GetBack(), width: 208, height: 303, posx: (i%(Math.ceil(noc*Ratio))) *SpaceX + SpaceX - 104 + LastYOff * (  i>=  (NumberOfCards + NumberOfCardsBonus) - ((NumberOfCards + NumberOfCardsBonus)%(Math.ceil(noc*Ratio))) ) , posy: Math.floor( i / (Math.ceil(noc*Ratio))  ) * SpaceY + SpaceY - 152 });//

    //Add a class to the object, this, does nothing except make us able to search for objects with the same class later in the code.
    $("#"+name).addClass("object");

    //Create the actual class for the object, this will add logic to the object.
    $("#"+name)[0].Cards = new Cards($("#"+name));
    $("#"+name)[0].Cards.Create(val, IM.GetImage(val), IM.GetImage(3), IM.GetBack(), DM.LastBonus(), Scale);


    //Add a mousedown event for the card, this mousedown will be run in the main
    //environment rather than the class environment to make sure that we have access
    //to all the data we need access to.
    $("#"+name).mousedown(function(e)
    {
        var Ready = 0;
        $(".object").each(function()
        {
            if (this.object.visible && (this.object.Turning==true || this.object.FlippedV==true))
            {
                Ready++;
            }
        });
        //Find all the objects with the tag/class card.
        $(".object").each(function()
        {
            //Check if the mouse clicked the object, if it's still part of the game, and if it has not been flipped.
            if (e.clickedobject
            && Ready<TurnedMax)
            {
                //Run the clicked event for the card, this will start events etc.
                this.object.Clicked();
                //Increase the turned counter, if we have turned the correct amount of objectto be compared
                //then compare them.
                if (this.Cards.Bonus == false)
                {
                    Turned++;
                    if (Turned==TurnedMax)
                    {
                        //We have turned the amount of object needed
                        //Find out which value the first object has, and use this as a base to compare if cards match.
                        //Also instantiate a counter for the amount of cards actually matching.
                        //It's done this way if you want a variable number of object needed for a match.
                        var Correct = this.object.value;
                        var CorrectAmount = 0;
                        $(".object").each(function()
                        {
                            //For each card, if they are flipped, are not going into hiding/deletion, and has the
                            //Correct value, increase the counter for the number of objects matching.
                            if (this.object.Flipped == true && this.object.Hiding==0 && this.object.value == Correct)
                                CorrectAmount++;

                        });

                        //If we have a correct match
                        if (CorrectAmount==TurnedMax)
                        {
                            $(".object").each(function()
                            {
                                //Foreach object that is flipped and not in hiding, delete them (aka. yay, you got a match).
                                if (this.object.Flipped==true && this.object.Hiding==0)
                                    this.object.SetVisible(false);
                            });
                        }

                        $(".object").each(function()
                        {
                            //Foreach objectthat was not in hiding and was not part of the match, unflip them again.
                            if (this.object.Flipped==true && this.object.Hiding==0)
                            this.object.Hide();
                        });

                        Turned=0;
                    }
                }
            }
        });
    });


}

// this sets the id of the loading bar (NOT USED YET):
$.loadCallback(function(percent){
        $("#loadingBar").width(400*percent);
  });
//initialize the start button
$("#startbutton").click(function(){
    $.playground().startGame(function(){
        $("#welcomeScreen").remove();
    });
})


//This is for the background animation (DEBUG)
$("#playground").registerCallback(function(){

$("#background1").x(($("#background1").x() + smallStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);
$("#background2").x(($("#background2").x() + smallStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);

$("#background3").x(($("#background3").x() + mediumStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);
$("#background4").x(($("#background4").x() + mediumStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);

$("#background5").x(($("#background5").x() + bigStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);
$("#background6").x(($("#background6").x() + bigStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);


//Basic Game Engine!!

$(".object").each(function()
{
    //For each card, perform their step event.
    this.object.Step();
});

}, REFRESH_RATE);
});

Answer 1

你说你正在使用 <meta http-equiv="X-UA-Compatible" content="IE=9"> .

这根本不可能有任何帮助。

在 IE9 或 IE8 中完全没有效果。

它将在 IE10 和 IE11 中产生影响，但这种影响将把浏览器拉低到向后兼容模式，这基本上意味着你告诉 IE10 和更高版本关闭它们的一些新功能并且伪装成 IE9。

那真的毫无意义；事实上，它可能弊大于利，因此我建议完全删除该行代码。

如果你必须有一个 X-UA-Compatible标志，唯一合理的值是 IE=edge .这将强制所有 IE 版本使用它们可用的最佳模式。在大多数情况下，这是默认设置，但在默认设置为其他内容的少数情况下，它可能会有所帮助。

但您在这里提示的真正问题是性能，我可以明确地告诉您，这与 X-UA-Compatible 完全无关。 flag -- 正如我所说，您设置它的方式无论如何都不会对 IE8 产生任何影响，所以它不是让事情变慢的原因。

最终，您对 IE8 的问题可能会归结为一个简单的事实，即它只是一个比更新版本慢得多的浏览器多。您可能根本无法让 IE8 的性能足以达到您想要的效果。

IE9 和 IE10 要好得多，所以您应该能够通过一些调整从它们获得合理的性能，所以您最好的希望可能是进行一些性能调整。

性能测试的最佳选择是升级到 IE11，它具有比 IE10 好得多的开发工具，包括一些非常好的用于分析网站性能的工具。

性能调整本身就是一个大话题(超出了本回答的范围)，但最终目标是找出导致最大瓶颈的原因，并解决这些问题。在大多数情况下，通常只有一两个主要问题阻碍了一切，处理它们通常足以改变现状。

所以我的建议是:下载 IE11 并尝试新开发工具中的新性能测试功能。希望这足以让您入门，但如果您仍然找不到问题，请尝试提出一个更具体的问题，了解为什么您的代码的特定部分很慢。

我建议的另一件事是尝试减少对 jQuery 等库的使用。

jQuery 非常有用，但它确实会影响性能。尽可能尝试切换到 native Javascript。

如果您做不到，请尝试减少调用同一电话的次数。例如:

$("#background1").x(($("#background1").x() + smallStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);

这调用了 $("#background1")两次。改为这样做:

var $bg1 = $("#background1");
$bg1.x(($bg1.x() + smallStarSpeed +PLAYGROUND_WIDTH) % (2 * PLAYGROUND_WIDTH) - PLAYGROUND_WIDTH);

更好的是，如果你能用 document.getElementByTagName 做到这一点而不是 jQuery，您将为自己节省更多的性能。

我还注意到您在该代码中重复了一些计算。显然，如果您可以整理一下以减少重复，也会有所帮助。

我希望这能给你一些思考的方向。