I'm working on an nft-art-generator app, the app generate multiple and differnte html canvas (as image).
Each canvas is a combination of 3 images, in other words, 3 images should be drawn in each canvas and after drawing on canvas i download it.
The Problem is that when i check the downloaded canvas, i get the same canvas. To be more precise I get the last generated canvas has been downloaded multiple time, it's like all canvas generated before are gone.
I think that happened because something in my code is running asynchronously.
Here is my React.js Code
const generateCollection = async()=>{
//In this exemple i want to generate 2 canvas only!!
for(var k = 1; k <= 2; k++){
drawLayer(data, k)
}
}
const drawLayer = (data, index)=>{
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d')
let sources = {};
//Get some random images url
const objURLs = getImagesURLs(data, index);
objURLs.forEach((url,i)=>{
const key = `image${i+1}`;
Object.assign(sources, {[key]: url})
})
loadImages(sources, function(images) {
objURLs.forEach((url,i)=>{
if (Boolean(url)) {
context.drawImage(images[`image${i+1}`], 0, 0, 230, 230)
}
})
});
setTimeout(()=> download(canvas.current, index), 1000);
}
const loadImages = (sources, callback)=> {
var images = {};
var loadedImages = 0;
var numImages = 0;
// get num of sources
for(var src in sources) {
numImages++;
}
for(var src in sources) {
images[src] = new Image();
images[src].onload = function() {
if(++loadedImages >= numImages) {
console.log("!! ", images )
callback(images);
}
};
images[src].src = sources[src];
}
}
const download = (canvas, index)=>{
console.log("Download: ", canvas)
var url = canvas.toDataURL("image/png");
var link = document.createElement('a');
link.download = `img_${index}.png`;
link.href = url;
link.click();
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<canvas
id="myCanvas"
ref={canvas}
width={230}
height={230}
/>
<Button onClick={()=>generateCollection()} ><Button>
Here is a live demo code based on
https://jsfiddle.net/vprdhomf/1/
I will appreciate any help, or suggestion!!
To lift from question comment:
Loading images is asynchronous, so callback is called asynchronously.
If all canvas combinations (of different sets of multiple images) have been completed in less than a second, the setTimeout call to download only sees the canvas in its final state. To resolve this you can either
Wait for each download to be initiated before creating the next download, or
Use multiple canvas elements, or perhaps
Store data URLs in an array for each canvas combination for downloading later.
If the images are loaded across domains, and the server doesn't allow cross domain requests, canvas.toDataURL throws a security exception. Fixing the fiddle using the URLs provided in it became impossible because of this.
Related
My ultimate goal is that I'm trying to convert an animated SMIL SVG into an APNG file. I have found no easy way to do this, and so I'm doing something a roundabout: I've written a node.js + express.js app that hosts a simple backend to get svg images on my local filesystem, and I've written a vue.js app that will go and pull those images and render them on a google chrome browser. I then play the SVG and try to capture rendered "frames", and save those frames as static png files (about 30 static PNG files for each second of SVG animation). I then plan to take those static png files & convert them over to a single animated png / apng file using another program. The part that I'm stuck on: actually trying to capture a rasterized "frame" of the svg.
Here's a snippet of code from my vue.js app which requests an SVG file, and renders it to a div, and then it tries to call a function takeSnap().
const file = await RequestsService.getFile(i);
const div = document.getElementById("svgContainer");
div.innerHTML = file.svg;
const { width, height } = div.children[0].getBBox();
console.debug(`width: ${width}, height: ${height}`);
const svg = div.children[0];
await svg.pauseAnimations();
let time = 0.0;
const interval = 1.0 / numFrames; // interval in seconds.
let count = 0;
while (time < file.duration) {
console.log(`time=${time}`);
await svg.setCurrentTime(time);
await this.takeSnap(svg, width, height);
time += interval;
console.debug(`file: ${file.fileName}_${count}`);
}
await svg.setCurrentTime(file.duration);
await this.takeSnap(svg, width, height);
I haven't been able to make a proper implementation of takeSnap(). I know that there are a slew of tools such as Canvg or HTML2png that go and directly render a webpage from the DOM. I've tried many different libraries, but none of them seem to be able to correctly render the frame of the SVG that chrome is correctly rendering. I don't blame the libraries: going from animated SVG XML file to actually rasterized pixels is a very difficult problem I think. But Chrome can do it, and what I'm wondering is... can I capture the browser engine output of chrome somehow?
Is there a way that I can get the rasterized pixel data produced by the blink browser engine in chrome & then save that rasterized pixel data into a png file? I know that I'll lose the transparency data of the SVG, but that's okay, I'll work around that later.
OK, this got a bit complicated. The script can now take SMIL animations with both <animate> and <animateTransform>. Essentially I take a snap shot of the SVG using Window.getComputedStyle() (for <animate> elements) and the matrix value using SVGAnimatedString.animVal (for <animateTransform> elements). A copy of the SVG is turned into a data URL and inserted into a <canvas>. From here it is exported as a PNG image.
In this example I use a data URL in the fetch function, but this can be replaced by a URL. The script has been tested with the SVG that OP provided.
var svgcontainer, svg, canvas, ctx, output, interval;
var num = 101;
const nsResolver = prefix => {
var ns = {
'svg': 'http://www.w3.org/2000/svg',
'xlink': 'http://www.w3.org/1999/xlink'
};
return ns[prefix] || null;
};
const takeSnap = function() {
// get all animateTransform elements
let animateXPath = document.evaluate('//svg:*[svg:animateTransform]', svg, nsResolver, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
// store all animateTransform animVal.matrix in a dataset attribute
Object.keys([...Array(animateXPath.snapshotLength)]).forEach(i => {
let node = animateXPath.snapshotItem(i);
let mStr = [...node.transform.animVal].map(animVal => {
let m = animVal.matrix;
return `matrix(${m.a} ${m.b} ${m.c} ${m.d} ${m.e} ${m.f})`;
}).join(' ');
node.dataset.transform = mStr;
});
// get all animate elements
animateXPath = document.evaluate('//svg:animate', svg, nsResolver, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
// store all animate properties in a dataset attribute on the target for the animation
Object.keys([...Array(animateXPath.snapshotLength)]).forEach(i => {
let node = animateXPath.snapshotItem(i);
let propName = node.getAttribute('attributeName');
let target = node.targetElement;
let computedVal = getComputedStyle(target)[propName];
target.dataset[propName] = computedVal;
});
// create a copy of the SVG DOM
let parser = new DOMParser();
let svgcopy = parser.parseFromString(svg.outerHTML, "application/xml");
// find all elements with a dataset attribute
animateXPath = svgcopy.evaluate('//svg:*[#*[starts-with(name(), "data")]]', svgcopy, nsResolver, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
// copy the animated property to a style or attribute on the same element
Object.keys([...Array(animateXPath.snapshotLength)]).forEach(i => {
let node = animateXPath.snapshotItem(i);
// for each data-
for (key in node.dataset) {
if (key == 'transform') {
node.setAttribute(key, node.dataset[key]);
} else {
node.style[key] = node.dataset[key];
}
}
});
// find all animate and animateTransform elements from the copy document
animateXPath = svgcopy.evaluate('//svg:*[starts-with(name(), "animate")]', svgcopy, nsResolver, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
// remove all animate and animateTransform elements from the copy document
Object.keys([...Array(animateXPath.snapshotLength)]).forEach(i => {
let node = animateXPath.snapshotItem(i);
node.remove();
});
// create a File object
let file = new File([svgcopy.rootElement.outerHTML], 'svg.svg', {
type: "image/svg+xml"
});
// and a reader
let reader = new FileReader();
reader.addEventListener('load', e => {
/* create a new image assign the result of the filereader
to the image src */
let img = new Image();
// wait got load
img.addEventListener('load', e => {
// update canvas with new image
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.fillStyle = 'white';
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.drawImage(e.target, 0, 0);
// create PNG image based on canvas
let img = new Image();
img.src = canvas.toDataURL("image/png");
output.append(img);
//let a = document.createElement('A');
//a.textContent = `Image-${num}`;
//a.href = canvas.toDataURL("image/png");
//a.download = `Image-${num}`;
//num++;
//output.append(a);
});
img.src = e.target.result;
});
// read the file as a data URL
reader.readAsDataURL(file);
};
document.addEventListener('DOMContentLoaded', e => {
svgcontainer = document.getElementById('svgcontainer');
canvas = document.getElementById('canvas');
output = document.getElementById('output');
ctx = canvas.getContext('2d');
fetch('data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4KPHN2ZyB3aWR0aD0iMjAwIiBoZWlnaHQ9IjIwMCIgdmVyc2lvbj0iMS4xIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAxMCAxMCI+CiAgPHJlY3QgeD0iMCIgeT0iMCIgd2lkdGg9IjQiIGhlaWdodD0iNCIgZmlsbD0ibmF2eSI+CiAgICA8YW5pbWF0ZSBhdHRyaWJ1dGVOYW1lPSJmaWxsIiBkdXI9IjNzIiBrZXlUaW1lcz0iMDsuMTsuMjsxIiB2YWx1ZXM9Im5hdnk7bGlnaHRibHVlO2JsdWU7bmF2eSIvPgogICAgPGFuaW1hdGVUcmFuc2Zvcm0gYWRkaXRpdmU9InN1bSIgYXR0cmlidXRlTmFtZT0idHJhbnNmb3JtIiBkdXI9IjNzIiBrZXlUaW1lcz0iMDsuNTsxIiB0eXBlPSJ0cmFuc2xhdGUiIHZhbHVlcz0iMCwwOzIsMjs0LDYiLz4KICAgIDxhbmltYXRlVHJhbnNmb3JtIGFkZGl0aXZlPSJzdW0iIGF0dHJpYnV0ZU5hbWU9InRyYW5zZm9ybSIgZHVyPSIzcyIga2V5VGltZXM9IjA7LjU7MSIgdHlwZT0icm90YXRlIiB2YWx1ZXM9IjAsMiwyOzMwLDIsMjstMTAsMiwyOyIvPgogIDwvcmVjdD4KPC9zdmc+CgoK').then(res => res.text()).then(text => {
let parser = new DOMParser();
let svgdoc = parser.parseFromString(text, "application/xml");
canvas.width = svgdoc.rootElement.getAttribute('width');
canvas.height = svgdoc.rootElement.getAttribute('height');
svgcontainer.innerHTML = svgdoc.rootElement.outerHTML;
svg = svgcontainer.querySelector('svg');
// set interval
interval = setInterval(takeSnap, 50);
// get all
let animateXPath = document.evaluate('//svg:*[starts-with(name(), "animate")]', svg, nsResolver, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
let animationArr = Object.keys([...Array(animateXPath.snapshotLength)]).map(i => {
let node = animateXPath.snapshotItem(i);
return new Promise((resolve, reject) => {
node.addEventListener('endEvent', e => {
resolve();
});
});
});
Promise.all(animationArr).then(value => {
clearInterval(interval);
});
});
});
<div style="display:flex">
<div id="svgcontainer"></div>
<canvas id="canvas" width="200" height="200"></canvas>
</div>
<p>Exported PNGs:</p>
<div id="output"></div>
I am storing base64 encoded images, and at the moment I can only create one code (i'm attempting to create two, but it appears the second is being overwritten). I don't get the over-arching concept of canvas drawing, so I believe that is the root of my issue when trying to solve this problem.
current behavior: It stores the same DataUrl in local storage twice. It does log the correct info. the favicon-green is getting stored, just not red
How do I encode multiple base64 images with canvas?
html:
<head>
...
<link id="favicon" rel="icon" src="/assets/favicon-red-16x16.ico.png">
</head>
<body>
...
<!-- hidden images to store -->
<img id="favicon-green" rel="icon" src="/assets/favicon-green-16x16.ico.png" width="16" height="16" />
<img id="favicon-red" rel="icon" src="/assets/favicon-red-16x16.ico.png" width="16" height="16" />
...
</body>
js:
// cache images
function storeImages() {
// my sorry attempt to create two canvas elements for two image encodings
var canvasGreen = document.createElement('canvas');
var canvasRed = document.createElement('canvas');
// painting both images
var ctxGreen = canvasGreen.getContext('2d');
var ctxRed = canvasRed.getContext('2d');
// getting both images from DOM
var favGreen = document.getElementById('favicon-green');
var favRed = document.getElementById('favicon-red');
// checking if images are already stored
var base64Green = localStorage.getItem('greenFavicon');
var base64Red = localStorage.getItem('redFavicon');
console.log('storing...')
if (base64Green == null && window.navigator.onLine || base64Red == null && window.navigator.onLine) {
ctxGreen.drawImage(favGreen, 0, 0);
ctxRed.drawImage(favRed, 0, 0);
// getting images (the DataUrl is currently the same for both)
base64Green = canvasGreen.toDataURL();
base64Red = canvasRed.toDataURL();
localStorage.setItem('greenFavicon', base64Green);
localStorage.setItem('redFavicon', base64Red);
console.log("are they equal : ", base64Green == base64Red); // returns true
}
}
storeImages();
I don't see anything particularly wrong with your code. If the code isn't a direct copy and paste, I would look through it with a fine-tooth come to make sure you don't switch any red and green around.
There shouldn't be any surprising mechanisms when it comes to converting canvases to data URLs.
Here is a quick example of two:
const a = document.createElement('canvas');
const b = document.createElement('canvas');
const aCtx = a.getContext('2d');
const bCtx = b.getContext('2d');
aCtx.fillStyle = '#000';
aCtx.fillRect(0, 0, a.width, a.height);
const aUrl = a.toDataURL();
const bUrl = b.toDataURL();
console.log(aUrl == bUrl, aUrl, bUrl);
console.log('First difference index:', Array.prototype.findIndex.call(aUrl, (aChar, index) => aChar !== bUrl[index]));
Notice that they are different. However, notice that they also start out very similar, and you have to go quite a ways over to start seeing differences (in my example, character 70). I would double-check that they are actually the same (by comparing them like I did). It could be it just looks the same.
Another thing you might do, which is more of a code style thing, but could also help with accidentally green and red mixups, is make a function to save just one, then call it twice.
const saveImage = (imageId, key) => {
if (localStorage.getItem(key)) {
return; // already saved
}
const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
const image = document.getElementById(imageId);
ctx.drawImage(image, 0, 0);
if (window.navigator.onLine) {
localStorage.setItem(key, canvas.toDataURL());
}
}
saveImage('favicon-green', 'greenFavicon');
saveImage('favicon-red', 'redFavicon');
Not only does that clean up your code and keep it DRY, but it also helps avoid accidental mix-ups between red and green in your function.
After some comments back and forth, I realized another possibility is you are trying to draw the images to the canvas before the images are loaded. This will cause it to draw blank images, but otherwise act like it is working fine.
You can quickly test this by console logging this:
console.log(image.width === 0);
after setting the image variable. If the value is true, then the image isn't loaded yet (before loading, images will have a width and height of 0). You need to make sure to wait until the image is loaded before trying to save it.
The best way to do this is with an addEventListener():
document.getElementById('favicon-green').addEventListener('load', () => {
saveImage('favicon-green', 'greenFavicon');
});
There is one more catch with this, in that if the image is somehow already loaded by the time that code runs, it'll never trigger. You need to look at the width of the image as well. Here is a function that does this all for you, and returns a Promise so you know it's done:
const saveImage = (imageId, key) => new Promise(resolve => {
if (localStorage.getItem(key)) {
return resolve(); // already saved
}
const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
const image = document.getElementById(imageId);
const onImageLoaded = () => {
ctx.drawImage(image, 0, 0);
if (window.navigator.onLine) {
localStorage.setItem(key, canvas.toDataURL());
}
resolve();
}
if (image.width > 0) {
onImageLoaded();
} else {
image.addEventListener('load', onImageLoaded);
}
});
saveImage('favicon-green', 'greenFavicon').then(() => console.log('saved'));
Long story short in another portion of the program I make canvases, convert them to DataURLs, then pass them over to the following portion to use as the icon image of the buttons. Whenever I set this.icon = "/path/to/image.jpg", it pulls it correctly, but since these images are not on disk, I am unsure how to
arrowHandler: function (arrow) {
var list = [];
var library = Ext.getCmp("library");
var buttons = Ext.getCmp("numbered").menu.buttons; //where the dataURLs are pushed in another portion of the program
function btn(num) {
var image = new Image;
image.src = buttons[num].dataURL;
this.xtype = "button";
this.height = 50;
this.width = 50;
this.icon = image; //where putting an actual path works correctly, but this code doesn't
this.num = num;
this.handler = function (btn) {
btn.up("button").menu.Style = this.num;
btn.up("button").fireEvent("selected", this.num);
};
}
for (var i = 0; i <= 0; i++)
library.items.items.push(new btn(i));
},
I am aware the loop is only going thru index 0 - it's like that purposefully for testing.
SOLUTION
The selected correct answer did provide the right way to set the icon with a DataURI, but it wasn't the fix to my issue. Turns out instead of doing
library.items.items.push(new btn(i));
I needed to be doing
library.add(new btn(i));
The error I kept encountering with pushing was "c.render() is not a function". I mention that solely to make it hopefully searchable for anyone else who encounters that error.
Should be the same as data uri, you'll have to convert it first.
https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toDataURL
var dataURL = canvas.toDataURL();
Here is a button fiddle:
https://fiddle.sencha.com/#view/editor&fiddle/1og6
This question already has answers here:
Tainted Canvas, due to CORS and SVG?
(2 answers)
Closed 4 years ago.
I have a directive in angular JS that allows exporting SVGs to a PNG. This works fine in other browsers, but in IE I get a security error.
I have tried all sorts of things, but it just doesn't seem to work.
I read somewhere that if I base64 encode it, then that would work, but it doesn't.
The code I have for drawing the SVG on the canvas is this:
// Private function for drawing our images
var drawImage = function (canvas, ctx, svgContainer) {
// Defer our promise
var deferred = $q.defer();
// Remove hidden layers
removeHidden(angular.element(clone));
// Create our data
var clone = angular.element(svgContainer[0].cloneNode(true)),
child = clone.children()[0];
// Remove hidden layers
removeHidden(angular.element(clone));
var s = new XMLSerializer(),
t = s.serializeToString(child),
base64 = 'data:image/svg+xml;base64,' + window.btoa(t);
console.log(base64);
var img = new Image();
// When the image has loaded
img.onload = function () {
// Create our dimensions
var viewBox = child.getAttribute('viewBox').split(' ');
console.log(viewBox);
var dimensions = {
width: viewBox[2],
height: viewBox[3]
};
console.log(img.width);
// Get our location
getNextLocation(canvas.width, canvas.height, dimensions);
// Draw our image using the context
ctx.drawImage(img, 0, 0, dimensions.width / 2, dimensions.height, location.x, location.y, location.width, location.height);
// Resolve our promise
deferred.resolve(location);
};
// Set the URL of the image
img.src = base64;
// Return our promise
return deferred.promise;
};
Before this I was creating a blob but that also caused the security error.
My main bit of code, is this bit here:
// Public function to generate the image
self.generateImage = function (onSuccess) {
// Reset our location
location = null;
counter = 0;
// Get our SVG
var target = document.getElementById(self.options.targets.containerId),
svgContainers = angular.element(target.getElementsByClassName(self.options.targets.svgContainerClassName)),
itemCount = svgContainers.length;
// Get our context
var canvas = document.getElementById('canvas'),
ctx = canvas.getContext('2d');
// Set our canvas height and width
setCanvasDimensions(canvas, itemCount);
// Create our array of promises
var promises = [];
// Draw our header and footer
drawHeader(canvas, ctx);
//// For each container
//for (var i = 0; i < itemCount; i++) {
// // Get our elements
// var svgContainer = svgContainers[i];
// // Draw our image and push our promise to the array
// promises.push(draw(canvas, ctx, svgContainer));
//}
promises.push(draw(canvas, ctx, svgContainers[0]));
// Finally add our footer to our promises array
promises.push(drawFooter(canvas, ctx));
// When all promises have resolve
$q.all(promises).then(function () {
console.log('all promises completed');
// Get our URL as a base64 string
var dataURL = canvas.toDataURL("image/png");
console.log('we have the image');
// Create our model
var model = {
teamName: self.options.team.name,
sport: self.options.team.sport,
data: dataURL
};
// Create our preview
self.create(model).then(function (response) {
console.log('saved to the database');
// Invoke our success callback
onSuccess(response);
});
})
};
As you can see I loop through each svg container and draw the SVG for each one. I have commented that out in this bit of code and just draw the first image.
The console.log directive after canvas.toDateURL never get's invoked and I get a security error.
The SVG is inline. From what I have read the issue might be due to the xlns declaration, but removing it still gives me the issue:
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
viewBox="0 0 259.5 131" enable-background="new 0 0 259.5 131" xml:space="preserve">
Does anyone know how I can solve this issue?
You need to set
img.crossOrigin= 'anonymous';
before
img.src=...
However, to make this work, you will also need to have
access-control-allow-origin: *
set in the response header of your image.
to try the solution, you can use 'http://fabricjs.com/assets/printio.png'(which has the proper header set) for example
Im trying to load in jpeg images, frame by frame to create an sequence animation of jpeg images. I'm attempting to load them in a recursive loop using javascript. I need to load images in linearly to achieve progressive playback of the animation. (start playback before all frames are loaded) I get a Stack overflow at line: 0 error from IE due to the natural recursion of the function. (My real code loads in over 60+ frames)
Here is a basic example of how I'm doing this:
var paths = ['image1.jpg', 'image2.jpg', 'image3.jpg']; //real code has 60+ frames
var images = [];
var load_index = 0;
var load = function(){
var img = new Image();
img.onload = function(){
if(load_index<=paths.length){
load_index++;
load();
}else{
alert('done loading');
}
}
img.src = paths[load_index];
images.push(img);
}
It seems I can avoid this error by using a setTimeout with an interval of 1 when calling the next step of the load. This seems to let IE "breathe" before loading the next image, but decreases the speed at which the images load dramatically.
Any one know how to avoid this stack overflow error?
http://cappuccino.org/discuss/2010/03/01/internet-explorer-global-variables-and-stack-overflows/
The above link suggests that wrapping the function to remove it from the window object will help avoid stack overflow errors. But I then see strangeness with it only getting about 15 frames through the sequence and just dies.
Put simply, don't use a recursive function for this situation, there isn't any need:
var paths = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
var images = [];
var loads = [];
/// all complete function, probably should be renamed to something with a
/// unique namespace unless you are working within your own function scope.
var done = function(){
alert('all loaded');
}
var loaded = function(e,t){
/// fallbacks for old IE
e = e||Event; t = e.target||e.srcElement;
/// keep a list of the loaded images, you can delete this later if wanted
loads.push( t.src );
if ( loads.length >= paths.length ) {
done();
}
}
var load = function(){
var i, l = paths.length, img;
for( i=0; i<l; i++ ){
images.push(img = new Image());
img.onload = loaded;
img.src = paths[i];
}
}
In fact, as you are finding, the method you are using currently is quite intensive. Instead, the above version doesn't create a new function for each onload listener (saves memory) and will trigger off as many concurrent loads as your browser will allow (rather than waiting for each image load).
(the above has been manually typed and not tested, as of yet)
update
Ah, then it makes more sense as to why you are doing things this way :) In that case then your first approach using the setTimeout would probably be the best solution (you should be able to use a timeout of 0). There is still room for rearranging things to see if you can avoid that though. The following may get around the problem...
var paths = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
var images = []; /// will contain the image objects
var loads = []; /// will contain loaded paths
var buffer = []; /// temporary buffer
var done = function(){ alert('all loaded'); }
var loaded = function(e,t){
e = e||Event; t = e.target||e.srcElement; loads.push( t.src );
/// you can do your "timing/start animation" calculation here...
/// check to see if we are complete
if ( loads.length >= paths.length ) { done(); }
/// if not fire off the next image load
else { next(); }
}
var next = function(){
/// current will be the next image
var current = buffer.shift();
/// set the load going for the current image
if ( current ) { current.img.src = current.path; }
}
var load = function(){
var i, l = paths.length, img;
for( i=0; i<l; i++ ){
img = new Image();
img.onload = loaded;
/// build up a list of images and paths to load
buffer.push({ img: img, path: paths[i] });
}
/// set everything going
next();
}
If the above doesn't do it, another way of getting around the issue would be to step through your list of paths, one at a time, and append a string of image markup (that would render off-screen) to the DOM with it's own onload="next()" handler... next() would be responsible for inserting the next image. By doing this it would hand off the triggering of the load and the subsequent load event to outside of your code, and should get around stacking calls.