Preload Images

preload.js

this.addEventListener("DOMContentLoaded", preloadImages, true);
 
var loadedImages = 0;
var imageArray = new Array("path-to-image", "path-to-image");
 
function preloadImages(e)
{
for (var i=0; i<imageArray.length; i++) {
var tempImage = new Image();
tempImage.addEventListener("load", trackProgress, true);
tempImage.src = imageArray[i];
}
}
 
function trackProgress() {
loadedImages++;
 
if (loadedImages == imageArray.length) {
imagesLoaded();
}
}
 
function imagesLoaded() {
// do something
}