////////////////////////////////////////////////////////////////////////
// Fireworks-Script (c) 2012, Dominik Scholz / go4u.de Webdesign
////////////////////////////////////////////////////////////////////////
var fireworks = {
///////////////////////////// configuration ////////////////////////////
// random colors
_color: ['#D0D0D0', '#FF0000', '#FFFF00', '#22FF00', '#2040FF', '#00CCFF', '#FF00FF', '#A319D6'],
// gravity factor
_gravity: 0.07,
// air resistance factor
_resistance: 0.975,
// zIndex of particles
_zIndex: 20000,
// maximal age of particles (in msec)
_maxAge: 2000,
// interval of appearing explosions (in msec)
_interval: fireworks_plugin_config.intensity,
// amount of particles per explosion
_particlesPerExplosion: fireworks_plugin_config.particle,
// maximal speed of particle at moment of explosion
_speed: 5,
///////////////////////////// private vars /////////////////////////////
_particles: [],
_bodyWidth: 0,
_bodyHeight: 0,
_count: 0,
_lastInterval: 0,
////////////////////////////// functions ///////////////////////////////
// init fireworks
init: function()
{
this._addEventListener(window, 'resize', function() { return fireworks.resize.apply(fireworks); });
this._addEventListener(window, 'load', function() { return fireworks.start.apply(fireworks); });
},
// add an event listener
_addEventListener: function(el, name, handler)
{
if (el.addEventListener)
el.addEventListener(name, handler, false);
else if (el.attachEvent)
el.attachEvent('on' + name, handler);
},
// start fireworks
start: function()
{
// init window size
this.resize();
// start to move snow
this._lastInterval = this._time();
requestAnimFrame(function() {fireworks._move();});
this._addExplosion();
},
// add a new explosion
_addExplosion: function()
{
var x = Math.floor(Math.random() * this._bodyWidth),
y = Math.floor((Math.random() * .5 + .1) * this._bodyHeight),
dx = Math.random() * 10 - 5,
dy = Math.random() * -2 - 1,
c1 = this._random(this._color),
c2 = this._random(this._color);
for (var i = 0; i < this._particlesPerExplosion; i++)
{
this._createParticle(
x,
y,
dx,
dy,
i / (this._particlesPerExplosion - 1) * 180 * Math.PI,
Math.random() * this._speed,
Math.random() > .5 ? c1 : c2
);
}
window.setTimeout(
function() { return fireworks._addExplosion.apply(fireworks);},
Math.random() * (this._interval[1] - this._interval[0]) + this._interval[0]
);
},
// get current time
_time: function()
{
return +new Date();
},
// return a random array element
_random: function(arr)
{
return arr[
Math.floor(
Math.random() * (arr.length)
)
];
},
// creates a new particle
_createParticle: function(x, y, dx, dy, rot, speed, color)
{
var el = null,
foundEl = false,
p = this._particles;
// look for old particle
for (var i = 0, l = p.length; i < l; i++)
if (p[i].data.age > 1)
{
el = p[i];
foundEl = true;
break;
}
// create span child for particles
if (!foundEl)
{
el = document.createElement('div');
el.className = 'particle';
el.style.position = 'absolute';
el.style.fontSize = '20px';
el.style.zIndex = this._zIndex;
el.style.width = '10px';
el.style.overflow = 'hidden';
el.innerHTML = '&#x25cf;';
}
el.style.left = x + 'px';
el.style.top = y + 'px';
el.style.color = color;
el.data = {
x: x,
y: y,
dx: Math.cos(rot) * speed + dx,
dy: Math.sin(rot) * speed + dy,
color: color,
age: Math.random() * .25
};
if (!foundEl)
{
document.getElementsByTagName('body')[0].appendChild(el);
this._particles.push(el);
}
},
// move existing particles
_move: function()
{
requestAnimFrame(function() {fireworks._move();});
// calculate movement factor
var dif = this._time() - this._lastInterval;
this._lastInterval = this._time();
var delta = dif / 20;
var el,
d,
p = this._particles,
r = Math.pow(this._resistance, delta),
g = this._gravity * delta,
a = dif / this._maxAge;
for (var i = 0, l = p.length; i < l; i++)
{
el = p[i];
d = el.data;
if (d.age > 1)
continue;
d.age += a;
d.dy += g;
d.dx *= r;
d.dy *= r;
d.x += d.dx * delta;
d.y += d.dy * delta;
if (d.x < 0)
{
d.dx *= -1;
d.x = 0;
}
if (d.x > this._bodyWidth)
{
d.dx *= -1;
d.x = this._bodyWidth;
}
if (d.y < 0)
{
d.dy *= -1;
d.y = 0;
}
if (d.y > this._bodyHeight)
{
d.dy *= -1;
d.y = this._bodyHeight;
}
if (d.age > 1)
d.x = d.y = 0;
el.style.left = d.x + 'px';
el.style.top = d.y + 'px';
el.style.color = (Math.random() * .5 + d.age >= 1) ? 'transparent' : d.color;
el.style.fontSize = (1 - d.age) * 5 + 5 + 'px';
}
},
// calculate new positions for all particles
resize: function()
{
// get new width and height
this._bodyWidth = this._getWindowWidth() - 10;
this._bodyHeight = this._getWindowHeight() - 20;
},
// get window width
_getWindowWidth: function()
{
return document.getElementsByTagName('body')[0].offsetWidth;
},
// get window height
_getWindowHeight: function()
{
var h = Math.max(self.innerHeight || 0, window.innerHeight || 0);
if (document.documentElement)
h = Math.max(h, document.documentElement.clientHeight || 0);
if (document.body)
{
h = Math.max(h, document.body.clientHeight || 0);
h = Math.max(h, document.body.scrollHeight || 0);
h = Math.max(h, document.body.offsetHeight || 0);
}
return h;
}
};
// shim layer with setTimeout fallback
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function (cb){
window.setTimeout(cb, 1000 / 60);
};
})();
fireworks.init();