$(function(){
var isFirstLoadImg = true;
var bgImg = ["img/hoge.jpg", "img/huga.jpg", "img/piyo.jpg"];
var index = Math.floor(Math.random() * bgImg.length);
loadImg(index);
function loadImg(i) {
var image = new Image();
image.onload = function(){
if (isFirstLoadImg) {
isFirstLoadImg = false;
$("#bg").css("background-image","url(\"" + bgImg[i] + "\")");
$("#bg").fadeIn(1000);
setIndex();
loadImg(index);
}
};
image.src = bg[i];
}
function setIndex() {
var index_current = index;
while (index == index_current) {
index = Math.floor(Math.random() * bgImg.length);
}
}
function changeBg(i) {
$("#bg").fadeOut(1000, function(){
$("#bg").css("background-image","url(\"" + bgImg[i] + "\")");
});
$("#bg").fadeIn(1000);
}
setInterval(function(){
changeBg(index);
setIndex();
loadImg(index);
}, 60000);
});