HTML5 Canvas实现烟花绽放特效_html5教程技巧-H5教程-PHP中文网

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：

XML/HTML Code 复制内容到剪贴板

nbsp;HTML>
html>
head>
title>Canvas 实现放烟花特效title>
metacharset="utf-8">
metahttp-equiv="X-UA-Compatible"content="IE=edge">
metaname="viewport"content="width=device-width,height=device-height,inital-scale=1.0,maximum-scale=1.0,user-scalable=no">
styletype="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>
divid="bg">
imgid="bgimg"src="http://img.ivsky.com/img/tupian/pre/201508/02/yuzhou_xingkong_yu_yueliang-006.jpg">
div>
scriptsrc="http://cdn.bootcss.com/jquery/2.2.0/jquery.min.js">script>
script>
$(function(){
varFireworks=function(){
varself=this;
// 产生烟花随机数
varrand=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 + w1x2|| x2 + w2x1|| y1 + h1y2|| y2 + h2y1);
};
//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){
varcountdown=self.partCount;
while(countdown--){
varnewParticle= {
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(){
vari=self.particles.length;
while(i--){
varp=self.particles[i];
varradians=p.angle * Math.PI / 180;
varvx=Math.cos(radians) * p.speed;
varvy=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(){
vari=self.particles.length;
while(i--){
varp=self.particles[i];
varcoordRand= (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){
varinverseDensity=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();
varrandrandAlpha= 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){
varnewFirework= {
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(){
vari=self.fireworks.length;
while(i--){
varf=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(){
vari=self.fireworks.length;
self.ctx.globalCompositeOperation='lighter';
while(i--){
varf=self.fireworks[i];
self.ctx.lineWidth= f.lineWidth;
varcoordRand= (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();
}
varfworks=newFireworks();
$('#info-toggle').on('click', function(e){
$('#info-inner').stop(false, true).slideToggle(100);
e.preventDefault();
});
});
script>
canvaswidth="1400"height="449">canvas>
body>
html>