添加雪花效果
(function(){
var app = app || {};
var Browser = $.browser;
if ($.browser.msie && $.browser.version <= 8) return;
var a = function () {
function r(a) {
return a * Math.random()
}
function s() {
return document.createElement("canvas")
}
function t() {
var a;
for (var d = 0; d < m; d++) a = d < m * .6 ? 0 : d < m * .8 ? 1 : d < m * .9 ? 2 : d < m * .98 ? 3 : 4, o[d] = [r(b), r(c), a]
}
function u() {
var a, d, e, f;
p += .01, d = Math.sin(p);
for (a = 0; a < m; a++) {
f = o[a], e = Math.sin(4 * p + a), f[1] += f[2] / 2 + (2 + e), f[0] += 6 * (d + e / 2) / (10 / f[2]), f[1] > c && (f[1] = -n, f[0] = r(b));
if (f[0] > b || f[0] < -n) d > 0 ? f[0] = -n : f[0] = b;
o[a] = f
}
}
function v() {
var a;
k.fillStyle = l, k.clearRect(0, 0, b, c), k.beginPath();
for (a = 0; a < m; a++) k.drawImage(i[o[a][2]], o[a][0], o[a][1]);
k.fill(), u()
}
function w(a) {
b = window.innerWidth,
c = window.innerHeight,
j !== undefined && (j.width = b, j.height = c, m = b * c / 6e3, l = k.createLinearGradient(0, 0, 0, c), t())
}
function x() {
//window.addEvent("resize", a.resizeHandler, !1),
$(window).resize(function(){
a.resizeHandler();
});
j = document.createElement("canvas"),
j.style.position = "fixed",
j.style.top = "0px",
j.style.left = "0px",
j.style.zIndex = 5e3,
j.style.pointerEvents = "none",
j.id = "canvas_snow",
document.body.appendChild(j),
k = j.getContext("2d"),
k.strokeStyle = "none",
d = s(), e = s(), f = s(), g = s(), h = s(), i = [d, e, f, g, h],
y({
canvas: d,
width: n * .4,
height: n * .4,
color: "#FFF",
soft: .05
}), y({
canvas: e,
width: n * .5,
height: n * .5,
color: "#FFF",
soft: .05
}), y({
canvas: f,
width: n * .6,
height: n * .6,
color: "#FFF",
soft: .3
}), y({
canvas: g,
width: n * .8,
height: n * .8,
color: "#FFF",
soft: .2
}), y({
canvas: h,
width: n,
height: n,
color: "#FFF",
soft: .05
}), w(null), app.snowTimer = setInterval(function () {
q(a.draw)
}, 50)
}
function y(a) {
var b, c, d, e, f, g, h, i, j;
d = a.width || 30, e = a.height || 30, f = d / 2, g = e / 2, i = a.color || "#FFF", h = a.soft || 0, b = a.canvas, b.width = d, b.height = d, c = b.getContext("2d"), c.clearRect(0, 0, d, e), j = c.createRadialGradient(f, g, 0, f, g, f), j.addColorStop(0, i), j.addColorStop(.1, i), j.addColorStop(.85, z(i, h)), j.addColorStop(1, z(i, 0)), c.fillStyle = j, c.fillRect(0, 0, d, e)
}
function z(a, b) {
var c, d, e;
return a = a.replace(/^s*#|s*$/g, ""), a.length === 3 && (a = a.replace(/([0-9a-fA-F])/g, "$1$1")), d = parseInt(a.substr(2, 2), 16), e = parseInt(a.substr(4, 2), 16), c = parseInt(a.substr(0, 2), 16), "rgba(" + c + ", " + d + ", " + e + ", " + b + ")"
}
var b, c, d, e, f, g, h, i = [],
j, k, l, m, n = 20,
o = [],
p = 0,
q = function () {
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
function (a) {
window.setTimeout(a, 62.5)
}
}();
return {
init: x,
draw: v,
resizeHandler: w
}
}();
(a.init(),setTimeout(function () {
clearTimeout(app.snowTimer), $("#canvas_snow").remove()
}, 120000));
})();
