//WBL 17 Jun 2010 Go back to r1.13 (ie non xmas operational version)
//WBL 9 Apr 2007 add cookie
//WBL 3 Mar 2007 add time+name for firefox
//WBL 17 June 2006 point both ie4up and ns6up pfeiffer_local.html r1.114
var CookieName = "animation";
function setCookie(value) {
var today = new Date()
var expires = new Date()
expires.setTime(today.getTime() + 1000*60*60*24*365)
document.cookie = CookieName + "=" + escape(value)
+ "; expires=" + expires.toGMTString()
}
function getCookie(def) {
if (navigator.cookieEnabled == 0) return 0;
var search = CookieName + "="
if (document.cookie.length > 0) { // if there are any cookies
offset = document.cookie.indexOf(search)
if (offset != -1) { // if cookie exists
offset += search.length
// set index of beginning of value
end = document.cookie.indexOf(";", offset)
// set index of end of cookie value
if (end == -1)
end = document.cookie.length
var s = unescape(document.cookie.substring(offset, end))
//alert("cookie is '"+s+"'");
return s;
}
}
return def;
}
//from http://www.assortedstuff.com/webmaster/beyond/jssample/snow/snow.html
//!-- Original: Altan (snow@altan.hr)
//!-- Web Site: http://www.altan.hr/snow
var no = 0; // snow number
var running = true;
var speed = 50; // smaller number moves the snow faster
var snowflake = "http://www.cs.ucl.ac.uk/cgi-bin/staff/W.Langdon/endpop.bat?";
var snowname = "http://www.cs.ucl.ac.uk/cgi-bin/staff/W.Langdon/endnam.bat?1";
var ns4up = (document.layers) ? 1 : 0; // browser sniffer
var ie4up = (document.all) ? 1 : 0;
var ns6up = (document.getElementById&&!document.all) ? 1 : 0;
var dx, xp, yp; // coordinate and position variables
var am, stx, sty; // amplitude and step variables
//--var i, doc_width = 800, doc_height = 600;
var i, doc_width = 800, doc_height = 2600;
if (ns4up||ns6up) {
doc_width = self.innerWidth;
//--doc_height = self.innerHeight;
} else if (ie4up) {
doc_width = document.body.clientWidth;
doc_height = document.body.clientHeight;
}
dx = new Array();
xp = new Array();
yp = new Array();
am = new Array();
stx = new Array();
sty = new Array();
function initialise(number) {
no=number;
for (i = 0; i < no; ++ i) {
dx[i] = 0; // set coordinate variables
xp[i] = Math.random()*(doc_width-50); // set position variables
yp[i] = Math.random()*doc_height;
am[i] = Math.random()*20; // set amplitude variables
stx[i] = 0.02 + Math.random()/10; // set step variables
sty[i] = 0.7 + Math.random(); // set step variables
var h=(ie4up||ns6up)? "http://www.cs.ucl.ac.uk/staff/W.Langdon/pfeiffer_local.html" : "http://www.cs.ucl.ac.uk/staff/W.Langdon/pfeiffer_server.html";
var t=""+
"![](\""+snowflake)
";
if(i==0) t = t + "Newest snowflake ";
if(ns6up) {//IE6 sort of works but looks bad
t= t + "";
}
t = t + "";
if (ns4up) { // set layers
document.write(""+t+"");
} else if (ie4up||ns6up) {
document.write(""+t+"
");
}
}
}//end initialise
//taken from pfeiffer_local.html r1.104
function Xp(i) {
return xp[i] + am[i]*Math.sin(dx[i]);
}
function move() {
var eastwind=(Math.max(0.5,Math.sin(new Date().getTime()/2000))-0.5)*8;
for (i = 0; i < no; ++ i) { // iterate for every dot
yp[i] += sty[i];
if (yp[i] > doc_height-100) {
xp[i] = Math.random()*Math.max(doc_width-am[i]-100,100);
yp[i] = 0;
stx[i] = 0.02 + Math.random()/10;
sty[i] = 0.7 + Math.random();
}
xp[i] -= eastwind;
if(xp[i]<-300) xp[i]=Math.max(doc_width-am[i]-100,100);
dx[i] += stx[i];
}
}//end move
function moveto(I,left,top) {
if (ns4up) {
document.layers["dot"+I].top = top;
document.layers["dot"+I].left = left;
}
else if (ie4up) {
document.all["dot"+I].style.pixelTop = top;
document.all["dot"+I].style.pixelLeft = left;
}
else if (ns6up) {
document.getElementById("dot"+I).style.top = top;
document.getElementById("dot"+I).style.left = left;
}
//document.getElementById("dot"+I).innerHTML = who(I);
}//end moveto
function snow() { // NS4 and IE and NS6 main animation function
doc_width = ns4up? self.innerWidth : (ns6up? window.innerWidth : document.body.clientWidth);
doc_height = ns4up? self.innerHeight:
(ns6up? window.innerHeight+window.pageYOffset :
Math.max(document.body.scrollHeight-500,500));
move(); //all the dots
for (var i = 0; i < no; ++ i) { // iterate for every dot
moveto(i,Xp(i),yp[i]);
}
if(running) {setTimeout("snow()", speed);}
}
function show() {
for (var i = 0; i < no; ++ i) { // iterate for every dot
document.getElementById("dot"+i).style.visibility="visible";
}
}
function hide() {
for (var i = 0; i < no; ++ i) { // iterate for every dot
document.getElementById("dot"+i).style.visibility="hidden";
}
}
function stop() {hide(); setCookie(0); running=false;}
function xxstart() { //IE7.0 name clash with start
show(); setCookie(no); running=true; snow();}