Home > Web Front-end > JS Tutorial > Simple fireworks special effects code implemented in JavaScript_javascript skills

Simple fireworks special effects code implemented in JavaScript_javascript skills

WBOY
Release: 2016-05-16 15:35:57
Original
2554 people have browsed it

The example in this article describes the simple fireworks special effects code implemented in JavaScript. Share it with everyone for your reference, the details are as follows:

This is a JavaScript firework special effect. Put it on your webpage during the Chinese New Year to wish everyone a happy Year of the Ox. Isn’t it great?

The screenshot of the running effect is as follows:

The online demo address is as follows:

http://demo.jb51.net/js/2015/js-yh-explode-style-demo/

The specific code is as follows:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>礼花特效</title>
<style type="text/css">
 html,body{background:#000; height:100%; margin:0px; padding:0px;color:#FFF;}
 .ball{color:#FF0000; position:absolute; font-size:16px;}
 .star{color:#FF0000; position:absolute; font-size:4px;}
</style>
<script type="text/javascript">
function Fireworks(sky, loop){
 this.sky = sky;
 this.skyWidth = document.body.clientWidth || document.documentElement.clientWidth;
 this.skyHeight= document.body.clientHeight || document.documentElement.clientHeight;
 this.x = this.y = 0;
 this.step = 20;
 this.delay = 30;
 this.stars = [];
 this.r = 10;
 this.step2 = 7;
 this.radius = 90;
 this.angle = 45;
 this.num = 16;
 this.loop = loop;
 this.degree = 2;
 this.t = 0;
 this.delt = 0;
 this.max = 30;
 this.cur = 1;
 this.points = null;
}
Fireworks.prototype = {
 init : function(){
  this.x = parseInt(this.skyWidth/1.3 * Math.random()) + this.skyWidth / 8;
  this.y = this.skyHeight;
  this._y = parseInt((this.skyHeight / 4) * Math.random()) + this.skyHeight / 5;
 },
 setOpacity : function(obj, p){
  if(p > 85){
   var opacity = 100 - (p - 85) * 4;
   if(document.all){
    obj.style.filter = "alpha(opacity=" + opacity + ")"; 
   }else{
    obj.style.MozOpacity = opacity / 100;
   }
  }
 },
 getNextPoint : function(degree, coeff, t){
  var tt = 1.0 - t;
  for(var rr = 1; rr <= degree; rr++){
   for(var i=0; i <= degree-rr; i++){
    coeff[i] = tt * coeff[i] + t * coeff[i+1];
   }
  }
  return coeff[0];
 },
 showBall : function(){
  this.ball = document.createElement("div");
  this.ball.innerHTML = "●";
  this.ball.className = "ball";
  this.ball.style.left = this.x + "px";
  this.ball.style.top = this.y + "px";
  this.sky.appendChild(this.ball);
 },
 moveBall : function(){
  var self = this;
  if(this.y > this._y){
   var p = parseInt((this.skyHeight - this.y) / (this.skyHeight - this._y)*10);
   this.y -= (this.step - p * 1.6);
   this.ball.style.fontSize = 16 - p + "px";
   this.ball.style.top = this.y + "px";
   setTimeout(function(){self.moveBall();}, this.delay);
  }else{
   this.fire();
  }
 },
 hideBall : function(){
  this.sky.removeChild(this.ball);
  this.ball = null;
 },
 showStars : function(){
  var colors = ['#FF0000','#FF00FF','#00FF00','#00FFFF','#FFFF00','#FF0000','#FF00FF','#00FF00','#00FFFF','#FFFF00'];
  var n = cs = parseInt(Math.random() * colors.length / 2);
  var cc = parseInt(Math.random() * colors.length / 2);
  var colorMode = parseInt(Math.random() * 2);
  var star = Math.round(Math.random()) == 1 &#63; "★" : "☆";
  this.r = 10;
  this.radius = Math.round(Math.random() * 30) + 60;
  this.num = Math.round(Math.random() * 5 + 5) * 2;
  this.angle = 180 / this.num * 2;
  for(var i=1; i<=this.num; i++){
   this.stars[i] = document.createElement("div");
   this.stars[i].innerHTML = star;
   this.stars[i].className = "star";
   if(colorMode == 1){
    this.stars[i].style.color = colors[n];
    if(++n > cs + cc)
     n = cs;
   }else{
    this.stars[i].style.color = colors[parseInt(Math.random() * colors.length)];
   }
   this.sky.appendChild(this.stars[i]);
  }
 },
 moveStars : function(){
  var self = this;
  if(this.r < this.radius){
   var p = this.step2 - parseInt(this.r / this.radius * 5);
   p = p < 1 &#63; 1 : p;
   this.r += p;
   p = parseInt(this.r / this.radius * 100);
   for(var i=1; i<=this.num; i++){
    this.stars[i].style.left = this.x - Math.round(this.r * Math.sin(Math.PI - (Math.PI / 180 * this.angle * i))) + "px";
    this.stars[i].style.top = this.y - Math.round(this.r * Math.cos(Math.PI - (Math.PI / 180 * this.angle * i))) + "px";
    this.stars[i].style.fontSize = 4 + p/10 + "px";
    this.setOpacity(this.stars[i], p);
   }
   setTimeout(function(){self.moveStars();}, this.delay);
  }else{
   setTimeout(function(){self.hideStars();}, 200 * Math.random());
  }
 },
 initBezier : function(){
  var coeff_x = [];
   var coeff_y = [];
  this.points = [];
  this.t = 0;
  this.delt = 1.0 / this.max;
  this.cur = 1;
  var a = parseInt(Math.random() * 5) * 90;
  coeff_x[0] = this.x;
  coeff_y[0] = this.y;
  for(var i=1; i<=this.num; i++){
   coeff_x[1] = this.x + Math.sin(Math.PI - (Math.PI / 180 * this.angle * i)) * this.radius/2;
   coeff_y[1] = this.y + Math.cos(Math.PI - (Math.PI / 180 * this.angle * i)) * this.radius/2;
   coeff_x[2] = this.x + Math.sin(Math.PI - (Math.PI / 180 * (a-this.angle * i))) * this.radius;
   coeff_y[2] = this.y + Math.cos(Math.PI - (Math.PI / 180 * (a-this.angle * i))) * this.radius;
   this.points[(i-1)*2] = coeff_x.slice(0);
   this.points[(i-1)*2+1] = coeff_y.slice(0);
  }
 },
 moveStars2 : function(){
  var self = this;
  if(this.cur < this.max){
   this.t += this.delt;
   this.cur++;
   p = parseInt(this.cur / this.max * 100);
   for(var i=1; i<=this.num; i++){
    this.stars[i].style.left = this.getNextPoint(this.degree, this.points[(i-1)*2], this.t) + "px";
    this.stars[i].style.top = this.getNextPoint(this.degree, this.points[(i-1)*2+1], this.t) + "px";
    this.stars[i].style.fontSize = 4 + p/10 + "px";
    this.setOpacity(this.stars[i], p);
   }
   setTimeout(function(){self.moveStars2();}, this.delay);
  }else{
   setTimeout(function(){self.hideStars();}, 200 * Math.random());
  }
 },
 hideStars : function(){
  for(var i=1; i<=this.num; i++){
   this.sky.removeChild(this.stars[i]);
   this.stars[i] = null;
   if(this.points != null){
    delete this.points[(i-1)*2];
    delete this.points[(i-1)*2+1];
   }
  }
  if(this.points){
   delete this.points;
  }
  this.points = null;
  if(this.loop){
   this.play();
  }
 },
 fire : function(){
  this.hideBall();
  this.showStars();
  var effect = parseInt(Math.random() * 2) + 1;
  switch(effect){
   case 1:
    this.moveStars();
    break;
   case 2:
    this.initBezier();
    this.moveStars2();
    break;
  }
 },
 play : function(){
  this.init();
  this.showBall();
  this.moveBall();
 }
};
window.onload = function(){
 for(var i=0; i<5; i++)
  new Fireworks(document.body, true).play();
};
</script>
</head>
<body>
</body>
</html>
Copy after login

I hope this article will be helpful to everyone in JavaScript programming.

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template