WordPress实现雪花飘落效果的四种代码与插件方案

<script type="text/javascript" language="javascript">
(function() {
function k(a, b, c) {
if (a.addEventListener) a.addEventListener(b, c, false);
else a.attachEvent && a.attachEvent("on" + b, c)
}
function g(a) {
if (typeof window.onload != "function") window.onload = a;
else {
var b = window.onload;
window.onload = function() {
b();
a()
}
}
}
function h() {
var a = {};
for (type in {
Top: "",
Left: ""
}) {
var b = type == "Top" ? "Y": "X";
if (typeof window["page" + b + "Offset"] != "undefined")
a[type.toLowerCase()] = window["page" + b + "Offset"];
else {
b = document.documentElement.clientHeight ? document.documentElement: document.body;
a[type.toLowerCase()] = b["scroll" + type]
}
}
return a
}
function l() {
var a = document.body,
b;
if (window.innerHeight) b = window.innerHeight;
else if (a.parentElement.clientHeight) b = a.parentElement.clientHeight;
else if (a && a.clientHeight) b = a.clientHeight;
return b
}
function i(a) {
this.parent = document.body;
this.createEl(this.parent, a);
this.size = Math.random() * 5 + 5;
this.el.style.width = Math.round(this.size) + "px";
this.el.style.height = Math.round(this.size) + "px";
this.maxLeft = document.body.offsetWidth - this.size;
this.maxTop = document.body.offsetHeight - this.size;
this.left = Math.random() * this.maxLeft;
this.top = h().top + 1;
this.angle = 1.4 + 0.2 * Math.random();
this.minAngle = 1.4;
this.maxAngle = 1.6;
this.angleDelta = 0.01 * Math.random();
this.speed = 2 + Math.random()
}
var j = false;
g(function() {
j = true
});
var f = true;
window.createSnow = function(a, b) {
if (j) {
var c = [],
m = setInterval(function() {
f && b > c.length && Math.random()
< b * 0.0025 && c.push(new i(a)); ! f && !c.length && clearInterval(m);
for (var e = h().top, n = l(), d = c.length - 1; d >= 0; d--)
if (c[d]) if (c[d].top < e || c[d].top + c[d].size + 1 > e + n) {
c[d].remove();
c[d] = null;
c.splice(d, 1)
} else {
c[d].move();
c[d].draw()
}
},
40);
k(window, "scroll",
function() {
for (var e = c.length - 1; e >= 0; e--) c[e].draw()
})
} else g(function() {
createSnow(a, b)
})
};
window.removeSnow = function() {
f = false
};
i.prototype = {
createEl: function(a, b) {
this.el = document.createElement("img");
this.el.setAttribute
("src", b + "雪花图片的绝对链接地址");
this.el.style.position = "absolute";
this.el.style.display = "block";
this.el.style.zIndex = "99999";
this.parent.appendChild(this.el)
},
move: function() {
if (this.angle < this.minAngle || this.angle > this.maxAngle)
this.angleDelta = -this.angleDelta;
this.angle += this.angleDelta;
this.left += this.speed * Math.cos(this.angle * Math.PI);
this.top -= this.speed * Math.sin(this.angle * Math.PI);
if (this.left < 0) this.left = this.maxLeft;
else if (this.left > this.maxLeft) this.left = 0
},
draw: function() {
this.el.style.top = Math.round(this.top) + "px";
this.el.style.left = Math.round(this.left) + "px"
},
remove: function() {
this.parent.removeChild(this.el);
this.parent = this.el = null
}
}
})();
createSnow("", 40);
</script>

 <html>
<head>
<script>
function start(){
var array=new Array();
var canvas=document.getElementById("mycanvas");
var context=canvas.getContext("2d");
for(var i=0;i<50;i++){
var Showsnow=new showsnow();
array.push(Showsnow);
}
time=setInterval(function (){
context.clearRect(0,0,canvas.width,canvas.height);
for(var i=0;i<array.length;i++){
array[i].move();
array[i].draw(context);
}
},500);
}
function showsnow(){
var y=parseInt(Math.random()*50)*10;
var x=parseInt(Math.random()*80)*10;
this.draw=function(context){
context.font="50px Calibri";
context.fillText("*",x,y);
}
this.move=function(){
y+=20;
if(y>600){
y=0;
}
}
}
</script>
</head>
<body>
<input type="button" value="start" onclick="start()" />
<br/>
<canvas id="mycanvas" height="600px" width="600px" style="border: 3px solid blue"></canvas>
</body>
</html>

function letItSnow(){
	var snowBox=document.getElementById("snowBox");
	var iArray=new Array();
	createSnow(snowBox,iArray);

}
function fallDown(temObj,iArray){
	var speed=2;
	var top=parseInt(temObj.style.top);
	if(top>510){//当到超过高度时候就删了它，减轻浏览器压力
		for(var i=0;i<iArray.length;i++){
			if(temObj==iArray[i]){
				iArray.splice(i,1);
				var snowBox=document.getElementById("snowBox");
				snowBox.removeChild(temObj);
				return false;
			}
		}
	}
	temObj.style.top=top+speed+"px";
	var wind=windBlow(temObj,top);
	temObj.style.left=parseInt(temObj.style.left)+wind*2+"px";
}
function windBlow(temObj,top){
	if(parseInt(Math.random())%2==1)
	return Math.sin(top/16);
	else return Math.cos(top/16);
}
function createSnow(snowBox,iArray){
	var temObj=document.createElement("i");
	var temText=document.createTextNode("*");
	temObj.appendChild(temText);
	temObj.style.left=parseInt(Math.random()*window.screen.width)+"px";
	temObj.style.top="0px";
	var temNum=parseInt(Math.random()*200);
	temObj.style.color="#"+temNum.toString(16)+temNum.toString(16)+temNum.toString(16);
	iArray.push(temObj);
	snowBox.appendChild(temObj);
	var temNum=0;
	while(temNum<10){
		temNum=parseInt(Math.random()*15);
	}
	temObj.style.fontSize=temNum+"px";

	var time=0;
	while(time<40){
		time=parseInt(Math.random()*50);
	}
	temObj.timer=setInterval(function(){
		fallDown(temObj,iArray);								
	},time);
	var snowInterval=0;
	while(snowInterval<500){
		snowInterval=parseInt(Math.random()*1000);
	}
	var createTimer=setTimeout(function(){
		createSnow(snowBox,iArray);	
		clearTimeout(createTimer);
	},snowInterval);
}