Javascript ipad safari停止运行内存不足的代码事件(使用1个图像对象进行画布)
(是的,我来自瑞典,所以我的英语可能并不完美;) 我的ipad内存有问题。此代码不会使broser崩溃,但会停止。在某些时候,它永远不会进入Image对象上的任何事件处理程序。我不知道为什么。。?我在论坛上搜索了几天,在谷歌上搜索了一些变通方法。但它们并不真正符合我想要达到的目标(?)。(因为我只有一个图像对象) 我创建的内容如下: 1个用户可见的主画布 我画的其他16幅画布 1个图像对象,用于加载图像 所有图像均为带有alpha的PNG,尺寸为900x373 px。所有画布的尺寸都相同 在另外16幅画布上,画了8幅图像 其目的是能够旋转具有可交换层的对象。 (1角度是一个不同角度的对象,因此当主循环运行时,它看起来像在旋转。)旋转应该由触摸/鼠标控制,但这应该说明我想要实现的目标 我知道这有很多代码要看,而且可能也不是最好的代码,因为我是javascript的新手。不过,它在我的chrome笔记本电脑上运行良好 我读过一些关于持有imageObjects引用的事件的文章,因此它们不会得到GC'd。但这是否意味着我只有一个图像对象? 我还尝试使用jquery语法添加和删除侦听器,但没有成功 如果有人愿意花时间回答这个问题,我们将不胜感激 向奥斯卡致意 变量的初始化:Javascript ipad safari停止运行内存不足的代码事件(使用1个图像对象进行画布),javascript,image,ipad,memory,canvas,Javascript,Image,Ipad,Memory,Canvas,(是的,我来自瑞典,所以我的英语可能并不完美;) 我的ipad内存有问题。此代码不会使broser崩溃,但会停止。在某些时候,它永远不会进入Image对象上的任何事件处理程序。我不知道为什么。。?我在论坛上搜索了几天,在谷歌上搜索了一些变通方法。但它们并不真正符合我想要达到的目标(?)。(因为我只有一个图像对象) 我创建的内容如下: 1个用户可见的主画布 我画的其他16幅画布 1个图像对象,用于加载图像 所有图像均为带有alpha的PNG,尺寸为900x373 px。所有画布的尺寸都相同 在另外
var drawingCanvas = null;
var context = null;
var numAngles = 8;
var angleStep = 32/ numAngles;
var canvasAngles = [];
var loadStatus = {};
var basePath = "assets_900/";
var layerPaths = [];
var layerPathsA = ["black/","v16/","f86/","fA00049/","fA00340/","fTG02/","fTG02/","fTJ02/"];
var layerPathsB = ["red/","v16/","f86/","fA00049/","fA00340/","fTG02/","fTG02/","fTJ02/"];
var layerPathsC = ["black/","v16/","f86/","fR134/","fA00340/","fTG02/","fTG02/","fTJ02/"];
var layerPathsD = ["red/","v16/","f86/","fR134/","fA00340/","fTG02/","fTG02/","fTJ02/"];
var layerPathsArr = [layerPathsA,layerPathsB,layerPathsC,layerPathsD];
layerPathsCounter = 0;
var numLayers = layerPaths.length;
var imageInit = null;
var SW = 900; //1920
var SH = 373; //796
var loopcounter = 0;
画布和其他stuf的首次设置:
layerPaths = layerPathsArr[0];
drawingCanvas = document.getElementById('myDrawing');
context = drawingCanvas.getContext('2d');
for(var i = 0; i < numAngles; i++){
var canvas = document.createElement('canvas');
var canvasContext = canvas.getContext('2d');
canvasContext.createImageData(SW, SH);
canvas.height = SH;
canvas.width = SW;
canvasAngles.push(canvas);
}
这是一个加载图像的循环:
当它加载了8幅图像时,它会在16幅画布中的一幅上绘制它们,然后在可见画布上绘制该画布。然后它加载一个新角度和8个新图像,依此类推
function loadImage(pathIndex,layerIndex,angleIndex){
if(layerIndex < layerPaths.length ){
//logger.log("path :" + pathIndex +" lajr : "+ layerIndex + " angl: " + angleIndex);
imageInit = new Image();
imageInit.onload = function(){
var canvas = canvasAngles[angleIndex];
var canvasContext = canvas.getContext('2d');
canvasContext.drawImage(imageInit,0, 0);
imageInit.onload = null;
imageInit.onerror = null;
imageInit.onabort = null;
imageInit.src = "data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==";
imageInit = null;
delete imageInit;
loadImage(pathIndex,layerIndex+1,angleIndex);
}
imageInit.onerror = function(){
logger.log("Error loading, retrying....");
loadImage(pathIndex,layerIndex,angleIndex);
}
imageInit.onabort = function(){
logger.log("Error loading (aborted)");
}
var path = "";
if(pathIndex < 10){
path = basePath + layerPaths[layerIndex] + "img000"+ pathIndex + ".png";
}else{
path = basePath + layerPaths[layerIndex] + "img00"+ pathIndex + ".png";
}
imageInit.src = path;
}else{
displayAngle(angleIndex);
if(angleIndex > numAngles-2){
logger.log("turns : " + loopcounter++ +" C: " + layerPathsCounter);
clearCanvases();
loadImage(0,0,0);
layerPathsCounter++;
if(layerPathsCounter > layerPathsArr.length-1){
layerPathsCounter = 0;
}
layerPaths = layerPathsArr[layerPathsCounter];
}else{
loadImage(pathIndex+angleStep,0,angleIndex+1);
}
}
}
函数加载图像(路径索引、层索引、角度索引){
if(层索引<层路径长度){
//logger.log(“路径:“+pathIndex+”lajr:“+layerIndex+”angl:”+angleIndex);
imageInit=新图像();
imageInit.onload=函数(){
var canvas=画布角度[angleIndex];
var canvasContext=canvas.getContext('2d');
drawImage(imageInit,0,0);
imageInit.onload=null;
imageInit.onerror=null;
imageInit.onabort=null;
imageInit.src=“data:image/gif;base64,r0lgodlhaqaabaiap///waaach5baeaaaaaaaaaaaaaaaaaaaaaaaaicraaow==”;
imageInit=null;
删除imageInit;
loadImage(路径索引、层索引+1、角度索引);
}
imageInit.onerror=函数(){
logger.log(“加载错误,重试…”);
loadImage(路径索引、层索引、角度索引);
}
imageInit.onabort=函数(){
logger.log(“加载错误(中止)”;
}
var路径=”;
如果(路径索引<10){
路径=基本路径+图层路径[layerIndex]+“img000”+路径索引+“.png”;
}否则{
路径=基本路径+图层路径[layerIndex]+“img00”+路径索引+“.png”;
}
imageInit.src=路径;
}否则{
显示角度(角度索引);
如果(角度索引>numAngles-2){
log(“turns:+loopcounter++++”C:+layerPathsCenter);
透明画布();
loadImage(0,0,0);
LayerPathsCenter++;
如果(图层路径中心>图层路径长度-1){
LayerPathsCenter=0;
}
layerPaths=LayerPathsar[LayerPathsCenter];
}否则{
loadImage(路径索引+角度步长,0,角度索引+1);
}
}
}
以下是几个辅助函数:
function clearCanvases(){
for(var i = 0; i < numAngles; i++){
var canvas = canvasAngles[i];
var canvasContext = canvas.getContext('2d');
canvasContext.clearRect(0,0,drawingCanvas.width, drawingCanvas.height);
}
}
function displayAngle(index){
context.clearRect(0,0,drawingCanvas.width, drawingCanvas.height);
var canvas = canvasAngles[index];
context.drawImage(canvas,0,0);
}
函数clearCanvases(){
对于(变量i=0;i
HTML:
<body >
<canvas id="myDrawing" width="900" height="373">
<p>Your browser doesn't support canvas. (HEHE)</p>
</canvas>
</body>
您的浏览器不支持画布。(呵呵)
一个选项卡中似乎只能加载~6.5 mb的数据。据我所知,没有办法释放这段记忆(?)
这将在ipad上加载约13 500kb的imqages,然后停止
它
<body >
<canvas id="myDrawing" width="900" height="373">
<p>Your browser doesn't support canvas. (HEHE)</p>
</canvas>
</body>