// Fireworks Effect Javascript
// copyright 3rd April 2005, 13th February 2009
// by Stephen Chapman http://javascript.about.com
// permission to use this Javascript on your web page is granted
// provided that all of the code in this script (including these
// comments) is used without any alteration

var stopafter = 0;
var firestop = []; var fire = []; var stdDOM = document.getElementById; var nsDOM = ((navigator.appName.indexOf('Netscape') != -1) && (parseInt(navigator.appVersion) == 4)); function pageWidth() { return window.innerWidth != null ? window.innerWidth : document.body != null ? document.body.clientWidth : 700; } function pageHeight() { return window.innerHeight != null ? window.innerHeight : document.body != null ? document.body.clientHeight : 500; } function posLeft() { return typeof window.pageXOffset != 'undefined' ? window.pageXOffset : document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft ? document.body.scrollLeft : 0; } function posTop() { return typeof window.pageYOffset != 'undefined' ? window.pageYOffset : document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop ? document.body.scrollTop : 0; } var hD = "0123456789ABCDEF"; function d2h(d) { return hD.substr(d >>> 4, 1) + hD.substr(d & 15, 1); } layernum = 0; piece = function(parent) { this.elem = null; if (nsDOM) { if (parent == null) this.elem = new Layer(1); else { this.elem = new Layer(1, parent.elem); this.style.visibility = "inherit"; } this.parent = parent; this.style = this.elem; } else if (stdDOM) { if (parent == null) this.parent = document.body; else this.parent = parent.elem; this.elem = document.createElement('div'); var xName = "xLayer" + layernum++; this.elem.setAttribute('id', xName); elemc = document.createTextNode('.'); this.elem.appendChild(elemc); this.parent.appendChild(this.elem); this.style = this.elem.style; document.getElementById(xName).style.lineHeight = '3px'; document.getElementById(xName).style.color = '#fff'; document.getElementById(xName).style.position = 'absolute'; } window[this.elem.id] = this; this.ay = .1; this.type = 0; }; piece.prototype.moveTo = function(x, y) { if (nsDOM) this.elem.moveTo(x, y); else { this.style.left = x + "px"; this.style.top = y + "px"; } }; piece.prototype.setC = function(colour) { if (nsDOM) this.elem.bgColor = colour; else this.style.backgroundColor = colour == null ? 'transparent' : colour; }; piece.prototype.fire = function(sx, sy, fw) { var a = Math.random() * Math.PI * 2; switch (fw) { case 1: var s = Math.random() * 2; break; case 2: var s = 2; break; case 3: var s = (Math.PI * 2) - a - Math.random(); break; case 4: var s = a - Math.random(); break; default: var s = Math.random() * 2; if (Math.random() > .6) s = 1.5; } this.dx = s * Math.sin(a); this.dy = s * Math.cos(a) - 2; this.x = sx; this.y = sy; this.moveTo(sx, sy); }; piece.prototype.sCol = function(hex, hex2, cl) { switch (cl) { case 1: this.setC("#" + hex + hex2 + "00"); break; case 2: this.setC("#00" + hex + "00"); break; case 3: this.setC("#00" + hex + hex2); break; case 4: this.setC("#" + hex + "0000"); break; case 5: this.setC("#" + hex + hex + "00"); break; case 6: this.setC("#" + hex + hex + hex); break; case 7: this.setC("#" + hex2 + hex + "00"); break; default: this.setC("#" + hex + hex2 + hex); } }; piece.prototype.animate = function(step, cl) { var colour = (step > 25) ? Math.random() * (380 - (step * 5)) : 255 - (step * 4); var hex = d2h(colour - 112); if (colour < 112) hex = d2h(colour); this.sCol(d2h(colour), hex, cl); this.dy += this.ay; this.x += this.dx; this.y += this.dy; this.moveTo(this.x, this.y); }; fo = function(numst) { this.id = "fo" + fo.count++; this.sp = new Array(); for (i = 0; i < numst; i++) { this.sp[i] = new piece(); if (nsDOM) { this.sp[i].style.clip.top = 0; this.sp[i].style.clip.left = 0; this.sp[i].style.clip.bottom = 3; this.sp[i].style.clip.right = 3; } else this.sp[i].style.clip = "rect(" + 0 + " " + 3 + " " + 3 + " " + 0 + ")"; this.sp[i].style.visibility = "visible"; } this.step = 0; window[this.id] = this; fire.push(this); firestop.push(setInterval("window." + this.id + ".animate()", 15)); }; fo.count = 0; fo.prototype.animate = function() { if (this.step > 55) this.step = 0; if (this.step == 0) { var x = posLeft() + 50 + (Math.random() * (pageWidth() - 200)); var y = posTop() + 50 + (Math.random() * (pageHeight() - 250)); var fw = Math.floor(Math.random() * 5); this.cl = Math.floor(Math.random() * 8); for (i = 0; i < this.sp.length; i++) this.sp[i].fire(x, y, fw); } this.step++; for (i = 0; i < this.sp.length; i++) this.sp[i].animate(this.step, this.cl); };
function stopfire() { for (var i = firestop.length - 1; i >= 0; i--) { clearInterval(firestop[i]); for (var j = fire[i].sp.length - 1; j >= 0; j--) { fire[i].sp[j].style.visibility = "hidden"; } } }
function fireworks() { new fo(50); setTimeout('new fo(50)', 750); if (stopafter > 0) { setTimeout('stopfire()', stopafter * 60000); } } window.onload = fireworks;