HTML5 Canvas实现烟花绽放的特效
导读：收集整理的这篇文章主要介绍了HTML5 Canvas实现烟花绽放的特效，觉得挺不错的，现在分享给大家，也给大家做个参考。这是一个款绚丽的HTML5 canvas动画，它将模拟的是我们生活中烟花绽放的动画特效，效果非常逼真，下面我们来简单分析...
收集整理的这篇文章主要介绍了HTML5 Canvas实现烟花绽放的特效，觉得挺不错的，现在分享给大家，也给大家做个参考。这是一个款绚丽的HTML5 canvas动画，它将模拟的是我们生活中烟花绽放的动画特效，效果非常逼真，下面我们来简单分析一下实现这款HTML5烟花特效的过程及代码，感兴趣的小伙伴们可以参考一下本文为大家带来了一款，免费而又安全环保的HTML5 Canvas实现的放烟花特效。
效果如下：
代码如下：
!DOCTYPE HTML>
html>
head>
tITle>
Canvas 实现放烟花特效/title>
meta charset="utf-8">
meta http-equiv="X-UA-Compatible" content="IE=Edge">
meta name="viewport" content="width=device-width,height=device-height,inital-scale=1.0,maximum-scale=1.0,user-scalable=no">
style type="text/css">
html,body{
height:100%;
margin:0;
padding:0}
ul,li{
text-indent:0;
text-decoration:none;
margin:0;
padding:0}
img{
border:0}
body{
background-color:#000;
color:#999;
font:100%/18px helvetica, arial, sans-serif}
canvas{
cursor:crosshair;
display:block;
left:0;
position:absolute;
top:0;
z-index:20}
#header img{
width:100%;
height:20%;
}
#bg img{
width:100%;
height:80%;
}
#header,#bg{
position:fixed;
left:0;
right:0;
z-index:10}
#header{
top:0}
#bg{
position:fixed;
z-index:1;
bottom:0}
audio{
position:fixed;
display:none;
bottom:0;
left:0;
right:0;
width:100%;
z-index:5}
/style>
/head>
body>
p id="bg">
img id="bgimg" src="http://img.ivsky.COM/img/tupian/PRe/201508/02/yuzhou_xingkong_yu_yueliang-006.jpg">
/p>
script src="http://cdn.bootcss.com/jquery/2.2.0/jquery.min.js">
/script>
script>
$(function(){
VAR Fireworks = function(){
var self = this;
// 产生烟花随机数 var rand = function(rMi, rMa){
//按位取反运算符 return ~~((Math.random()*(rMa-rMi+1))+rMi);
}
,hittest = function(x1, y1, w1, h1, x2, y2, w2, h2){
return !(x1 + w1 x2 || x2 + w2 x1 || y1 + h1 y2 || y2 + h2 y1);
}
;
//请求动画帧 window.requestAnimFrame=function(){
return window.requestAnimationFrame ||window.webkitRequestAnimationFrame ||window.mozRequestAnimationFrame ||window.oRequestAnimationFrame ||window.msRequestAnimationFrame ||function(callback){
window.setTimeout(callback,1000/60);
}
}
();
self.init = function(){
self.canvas = document.createElement('canvas');
//canvas 全屏 selfself.canvas.width = self.cw = $(window).innerWidth();
selfself.canvas.height = self.ch = $(window).innerHeight();
self.particles = [];
self.partCount = 150;
self.fireworks = [];
selfself.mx = self.cw/2;
selfself.my = self.ch/2;
self.currentHue = 30;
self.partSpeed = 5;
self.partSpeedVariance = 10;
self.partWind = 50;
self.partFriction = 5;
self.partGravity = 1;
self.hueMin = 0;
self.hueMax = 360;
self.fworkSpeed = 4;
self.fworkAccel = 10;
self.hueVariance = 30;
self.flickerDensity = 25;
self.showShockwave = true;
self.showTarget = false;
self.clearAlpha = 25;
$(document.body).append(self.canvas);
selfself.ctx = self.canvas.getContext('2d');
self.ctx.lineCap = 'round';
self.ctx.lineJoin = 'round';
self.lineWidth = 1;
self.bindEvents();
self.canvasLoop();
self.canvas.onselectstart = function() {
return false;
}
;
}
;
// 创建粒子 self.createParticles = function(x,y, hue){
var countdown = self.partCount;
while(countdown--){
var newParticle = {
x: x, y: y, coordLast: [ {
x: x, y: y}
, {
x: x, y: y}
, {
x: x, y: y}
], angle: rand(0, 360), speed: rand(((self.partSpeed - self.partSpeedVariance) = 0) ? 1 : self.partSpeed - self.partSpeedVariance, (self.partSpeed + self.partSpeedVariance)), friction: 1 - self.partFriction/100, gravity: self.partGravity/2, hue: rand(hue-self.hueVariance, hue+self.hueVariance), brightness: rand(50, 80), alpha: rand(40,100)/100, decay: rand(10, 50)/1000, wind: (rand(0, self.partWind) - (self.partWind/2))/25, lineWidth: self.lineWidth }
;
self.particles.push(newParticle);
}
}
;
// 更新粒子 self.updateParticles = function(){
var i = self.particles.length;
while(i--){
var p = self.particles[i];
var radians = p.angle * Math.PI / 180;
var vx = Math.cos(radians) * p.speed;
var vy = Math.sin(radians) * p.speed;
p.speed *= p.friction;
p.coordLast[2].x = p.coordLast[1].x;
p.coordLast[2].y = p.coordLast[1].y;
p.coordLast[1].x = p.coordLast[0].x;
p.coordLast[1].y = p.coordLast[0].y;
p.coordLast[0].x = p.x;
p.coordLast[0].y = p.y;
p.x += vx;
p.y += vy;
p.y += p.gravity;
p.angle += p.wind;
p.alpha -= p.decay;
if(!hitTest(0,0,self.cw,self.ch,p.x-p.radius, p.y-p.radius, p.radius*2, p.radius*2) || p.alpha .05){
self.particles.splice(i, 1);
}
}
;
}
;
// 绘制粒子 self.drawParticles = function(){
var i = self.particles.length;
while(i--){
var p = self.particles[i];
var coordRand = (rand(1,3)-1);
self.ctx.beginPath();
self.ctx.moveTo(Math.round(p.coordLast[coordRand].x), Math.round(p.coordLast[coordRand].y));
self.ctx.lineto(Math.round(p.x), Math.round(p.y));
self.ctx.closePath();
self.ctx.strokeStyle = 'hsla('+p.hue+', 100%, '+p.brightness+'%, '+p.alpha+')';
self.ctx.stroke();
if(self.flickerDensity >
0){
var inverseDensity = 50 - self.flickerDensity;
if(rand(0, inverseDensity) === inverseDensity){
self.ctx.beginPath();
self.ctx.arc(Math.round(p.x), Math.round(p.y), rand(p.lineWidth,p.lineWidth+3)/2, 0, Math.PI*2, false) self.ctx.closePath();
var randrandAlpha = rand(50,100)/100;
self.ctx.fillStyle = 'hsla('+p.hue+', 100%, '+p.brightness+'%, '+randAlpha+')';
self.ctx.fill();
}
}
}
;
}
;
// 创建烟花 self.createFireworks = function(startX, startY, targetX, targetY){
var newFirework = {
x: startX, y: startY, startX: startX, startY: startY, hitX: false, hitY: false, coordLast: [ {
x: startX, y: startY}
, {
x: startX, y: startY}
, {
x: startX, y: startY}
], targetX: targetX, targetY: targetY, speed: self.fworkSpeed, angle: Math.atan2(targetY - startY, targetX - startX), shockwaveAngle: Math.atan2(targetY - startY, targetX - startX)+(90*(Math.PI/180)), acceleration: self.fworkAccel/100, hue: self.currentHue, brightness: rand(50, 80), alpha: rand(50,100)/100, lineWidth: self.lineWidth }
;
self.fireworks.push(newFirework);
}
;
// 更新烟花 self.updateFireworks = function(){
var i = self.fireworks.length;
while(i--){
var f = self.fireworks[i];
self.ctx.lineWidth = f.lineWidth;
vx = Math.cos(f.angle) * f.speed, vy = Math.sin(f.angle) * f.speed;
f.speed *= 1 + f.acceleration;
f.coordLast[2].x = f.coordLast[1].x;
f.coordLast[2].y = f.coordLast[1].y;
f.coordLast[1].x = f.coordLast[0].x;
f.coordLast[1].y = f.coordLast[0].y;
f.coordLast[0].x = f.x;
f.coordLast[0].y = f.y;
if(f.startX >
= f.targetX){
if(f.x + vx = f.targetX){
ff.x = f.targetX;
f.hitX = true;
}
else {
f.x += vx;
}
}
else {
if(f.x + vx >
= f.targetX){
ff.x = f.targetX;
f.hitX = true;
}
else {
f.x += vx;
}
}
if(f.startY >
= f.targetY){
if(f.y + vy = f.targetY){
ff.y = f.targetY;
f.hitY = true;
}
else {
f.y += vy;
}
}
else {
if(f.y + vy >
= f.targetY){
ff.y = f.targetY;
f.hitY = true;
}
else {
f.y += vy;
}
}
if(f.hitX &
&
f.hitY){
self.createParticles(f.targetX, f.targetY, f.hue);
self.fireworks.splice(i, 1);
}
}
;
}
;
// 绘制烟花 self.drawFireworks = function(){
var i = self.fireworks.length;
self.ctx.globalCompositeoperation = 'lighter';
while(i--){
var f = self.fireworks[i];
self.ctx.lineWidth = f.lineWidth;
var coordRand = (rand(1,3)-1);
self.ctx.beginPath();
self.ctx.moveTo(Math.round(f.coordLast[coordRand].x), Math.round(f.coordLast[coordRand].y));
self.ctx.lineTo(Math.round(f.x), Math.round(f.y));
self.ctx.closePath();
self.ctx.strokeStyle = 'hsla('+f.hue+', 100%, '+f.brightness+'%, '+f.alpha+')';
self.ctx.stroke();
if(self.showTarget){
self.ctx.save();
self.ctx.beginPath();
self.ctx.arc(Math.round(f.targetX), Math.round(f.targetY), rand(1,8), 0, Math.PI*2, false) self.ctx.closePath();
self.ctx.lineWidth = 1;
self.ctx.stroke();
self.ctx.reStore();
}
if(self.showShockwave){
self.ctx.save();
self.ctx.translate(Math.round(f.x), Math.round(f.y));
self.ctx.rotate(f.shockwaveAngle);
self.ctx.beginPath();
self.ctx.arc(0, 0, 1*(f.speed/5), 0, Math.PI, true);
self.ctx.strokeStyle = 'hsla('+f.hue+', 100%, '+f.brightness+'%, '+rand(25, 60)/100+')';
self.ctx.lineWidth = f.lineWidth;
self.ctx.stroke();
self.ctx.restore();
}
}
;
}
;
// 绑定事件 self.bindEvents = function(){
$(window).on('resize', function(){
clearTimeout(self.timeout);
self.timeout = setTimeout(function() {
selfself.canvas.width = self.cw = $(window).innerWidth();
selfself.canvas.height = self.ch = $(window).innerHeight();
self.ctx.lineCap = 'round';
self.ctx.lineJoin = 'round';
}
, 100);
}
);
$(self.canvas).on('mousedown', function(e){
self.mx = e.pageX - self.canvas.offsetLeft;
self.my = e.pageY - self.canvas.offsetTop;
self.currentHue = rand(self.hueMin, self.hueMax);
self.createFireworks(self.cw/2, self.ch, self.mx, self.my);
$(self.canvas).on('mouSEMove.fireworks', function(e){
self.mx = e.pageX - self.canvas.offsetLeft;
self.my = e.pageY - self.canvas.offsetTop;
self.currentHue = rand(self.hueMin, self.hueMax);
self.createFireworks(self.cw/2, self.ch, self.mx, self.my);
}
);
}
);
$(self.canvas).on('mouseup', function(e){
$(self.canvas).off('mousemove.fireworks');
}
);
}
;
self.clear = function(){
self.particles = [];
self.fireworks = [];
self.ctx.clearRect(0, 0, self.cw, self.ch);
}
;
self.canvasLoop = function(){
requestAnimFrame(self.canvasLoop, self.canvas);
self.ctx.globalCompositeOperation = 'destination-out';
self.ctx.fillStyle = 'rgba(0,0,0,'+self.clearAlpha/100+')';
self.ctx.fillRect(0,0,self.cw,self.ch);
self.updateFireworks();
self.updateParticles();
self.drawFireworks();
self.drawParticles();
}
;
self.init();
}
var fworks = new Fireworks();
$('#info-toggle').on('click', function(e){
$('#info-inner').stop(false, true).slideToggle(100);
e.preventDefault();
}
);
}
);
/script>
canvas width="1400" height="449">
/canvas>
/body>
/html>
是不是被HTML5强大的效果惊呆了，一饱眼福了吧。
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以上就是HTML5 Canvas实现烟花绽放的特效的详细内容，更多请关注其它相关文章！
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