Code:
/*
DHTML Snowstorm! OO-style Jascript-based Snow effect
----------------------------------------------------
Initializes after body onload() by default (via addEventHandler() call at bottom.)
To customize properties, edit below or override configuration after this script
has run (but before body.onload), eg. snowStorm.snowStick = false;
*/
var snowStorm = null;
function SnowStorm() {
// --- PROPERTIES ---
this.flakesMax = 128; // Limit total amount of snow made (falling + sticking)
this.flakesMaxActive = 64; // Limit amount of snow falling at once (less = lower CPU use)
this.animationInterval = 33; // Theoretical "miliseconds per frame" measurement. 20 = fast + smooth, but high CPU use. 50 = more conservative, but slower
this.flakeBottom = null; // Integer for Y axis snow limit, 0 or null for "full-screen" snow effect
this.targetElement = null; // element which snow will be appended to (document body if null/undefined) - can be an element ID string, or a DOM node reference
this.followMouse = true; // Snow will change movement with the user's mouse
this.snowColor = '#fff'; // Don't eat (or use?) yellow snow.
this.snowCharacter = '•'; // • = bullet, · is square on some systems etc.
this.snowStick = true; // Whether or not snow should "stick" at the bottom. When off, will never collect.
this.useMeltEffect = true; // When recycling fallen snow (or rarely, when falling), have it "melt" and fade out if browser supports it
this.useTwinkleEffect = false; // Allow snow to randomly "flicker" in and out of view while falling
this.usePositionFixed = false; // true = snow not affected by window scroll. may increase CPU load, disabled by default - if enabled, used only where supported
// --- less-used bits ---
this.flakeLeftOffset = 0; // amount to subtract from edges of container
this.flakeRightOffset = 0; // amount to subtract from edges of container
this.flakeWidth = 8; // max pixel width for snow element
this.flakeHeight = 8; // max pixel height for snow element
this.vMaxX = 5; // Maximum X velocity range for snow
this.vMaxY = 4; // Maximum Y velocity range
this.zIndex = 0; // CSS stacking order applied to each snowflake
// --- End of user section ---
// jslint global declarations
/*global window, document, navigator, clearInterval, setInterval */
var addEvent = (typeof(window.attachEvent)=='undefined'?function(o,evtName,evtHandler) {
return o.addEventListener(evtName,evtHandler,false);
}:function(o,evtName,evtHandler) {
return o.attachEvent('on'+evtName,evtHandler);
});
var removeEvent = (typeof(window.attachEvent)=='undefined'?function(o,evtName,evtHandler) {
return o.removeEventListener(evtName,evtHandler,false);
}:function(o,evtName,evtHandler) {
return o.detachEvent('on'+evtName,evtHandler);
});
function rnd(n,min) {
if (isNaN(min)) {
min = 0;
}
return (Math.random()*n)+min;
}
function plusMinus(n) {
return (parseInt(rnd(2),10)==1?n*-1:n);
}
var s = this;
var storm = this;
this.timers = [];
this.flakes = [];
this.disabled = false;
this.active = false;
var isIE = navigator.userAgent.match(/msie/i);
var isIE6 = navigator.userAgent.match(/msie 6/i);
var isOldIE = (isIE && (isIE6 || navigator.userAgent.match(/msie 5/i)));
var isWin9X = navigator.appVersion.match(/windows 98/i);
var isiPhone = navigator.userAgent.match(/iphone/i);
var isBackCompatIE = (isIE && documen*****mpatMode == 'BackCompat');
var noFixed = ((isBackCompatIE || isIE6 || isiPhone)?true:false);
var screenX = null;
var screenX2 = null;
var screenY = null;
var scrollY = null;
var vRndX = null;
var vRndY = null;
var windOffset = 1;
var windMultiplier = 2;
var flakeTypes = 6;
var fixedForEverything = false;
var opacitySupported = (function(){