<!DOCTYPE html>
<html dir="ltr" lang="zh-CN">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width" />
<title>点击夜空欣赏烟花</title> <script type="text/javascript" src="http://app.46465.com/html5/qw/jquery.min.js"></script><script type="text/javascript">var dataForWeixin = {appId: "gh_ff79a97cd7f3",TLImg: "http://app.46465.com/html5/yh/logo.jpg",url: "http://app.46465.com/html5/yh/",title: "经典寂寞的烟花欣赏，如果觉得好看请您分享到微信里",desc: "分享到微信，发送给朋友或朋友圈，才能体现你的无私的爱！"};var onBridgeReady = function(){WeixinJSBridge.on('menu:share:appmessage', function(argv){var infos = $("#infos").text(); WeixinJSBridge.invoke('sendAppMessage', {"appid": dataForWeixin.appId,"img_url": dataForWeixin.TLImg,"img_width": "120","img_height": "120","link": dataForWeixin.url + '?f=wx_hy_bb',"title": infos + dataForWeixin.title,"desc": dataForWeixin.desc });setTimeout(function () {location.href = "http://app.46465.com/html5/yh/";}, 1500); });WeixinJSBridge.on('menu:share:timeline', function(argv){var infos = $("#infos").text(); WeixinJSBridge.invoke('shareTimeline', {"appid": dataForWeixin.appId,"img_url":dataForWeixin.TLImg,"img_width": "120","img_height": "120","link": dataForWeixin.url + '?f=wx_pyq_bb',"title": infos + dataForWeixin.title,"desc": dataForWeixin.desc});setTimeout(function () {location.href = "http://app.46465.com/html5/yh/";}, 1500); });};if(document.addEventListener){document.addEventListener('WeixinJSBridgeReady', onBridgeReady, false);}else if(document.attachEvent){document.attachEvent('WeixinJSBridgeReady', onBridgeReady);document.attachEvent('onWeixinJSBridgeReady', onBridgeReady);} </script>
<style>
/* basic styles for black background and crosshair cursor */
body {background: #000;margin: 0;
}canvas {cursor: crosshair;display: block;
}
.STYLE1 {color: #333333}
</style>
</head>
<div style="text-align:center;clear:both"></div>
<canvas id="canvas"><span class="STYLE1">Open IE effect more perfect </span></canvas>
<script>
// when animating on canvas, it is best to use requestAnimationFrame instead of setTimeout or setInterval
// not supported in all browsers though and sometimes needs a prefix, so we need a shim
window.requestAnimFrame = ( function() {return window.requestAnimationFrame ||window.webkitRequestAnimationFrame ||window.mozRequestAnimationFrame ||function( callback ) {window.setTimeout( callback, 1000 / 60 );};
})();// now we will setup our basic variables for the demo
var canvas = document.getElementById( 'canvas' ),ctx = canvas.getContext( '2d' ),// full screen dimensionscw = window.innerWidth,ch = window.innerHeight,// firework collectionfireworks = [],// particle collectionparticles = [],// starting huehue = 120,// when launching fireworks with a click, too many get launched at once without a limiter, one launch per 5 loop tickslimiterTotal = 5,limiterTick = 0,// this will time the auto launches of fireworks, one launch per 80 loop tickstimerTotal = 80,timerTick = 0,mousedown = false,// mouse x coordinate,mx,// mouse y coordinatemy;// set canvas dimensions
canvas.width = cw;
canvas.height = ch;// now we are going to setup our function placeholders for the entire demo// get a random number within a range
function random( min, max ) {return Math.random() * ( max - min ) + min;
}// calculate the distance between two points
function calculateDistance( p1x, p1y, p2x, p2y ) {var xDistance = p1x - p2x,yDistance = p1y - p2y;return Math.sqrt( Math.pow( xDistance, 2 ) + Math.pow( yDistance, 2 ) );
}// create firework
function Firework( sx, sy, tx, ty ) {// actual coordinatesthis.x = sx;this.y = sy;// starting coordinatesthis.sx = sx;this.sy = sy;// target coordinatesthis.tx = tx;this.ty = ty;// distance from starting point to targetthis.distanceToTarget = calculateDistance( sx, sy, tx, ty );this.distanceTraveled = 0;// track the past coordinates of each firework to create a trail effect, increase the coordinate count to create more prominent trailsthis.coordinates = [];this.coordinateCount = 3;// populate initial coordinate collection with the current coordinateswhile( this.coordinateCount-- ) {this.coordinates.push( [ this.x, this.y ] );}this.angle = Math.atan2( ty - sy, tx - sx );this.speed = 2;this.acceleration = 1.05;this.brightness = random( 50, 70 );// circle target indicator radiusthis.targetRadius = 1;
}// update firework
Firework.prototype.update = function( index ) {// remove last item in coordinates arraythis.coordinates.pop();// add current coordinates to the start of the arraythis.coordinates.unshift( [ this.x, this.y ] );// cycle the circle target indicator radiusif( this.targetRadius < 8 ) {this.targetRadius += 0.3;} else {this.targetRadius = 1;}// speed up the fireworkthis.speed *= this.acceleration;// get the current velocities based on angle and speedvar vx = Math.cos( this.angle ) * this.speed,vy = Math.sin( this.angle ) * this.speed;// how far will the firework have traveled with velocities applied?this.distanceTraveled = calculateDistance( this.sx, this.sy, this.x + vx, this.y + vy );// if the distance traveled, including velocities, is greater than the initial distance to the target, then the target has been reachedif( this.distanceTraveled >= this.distanceToTarget ) {createParticles( this.tx, this.ty );// remove the firework, use the index passed into the update function to determine which to removefireworks.splice( index, 1 );} else {// target not reached, keep travelingthis.x += vx;this.y += vy;}
}// draw firework
Firework.prototype.draw = function() {ctx.beginPath();// move to the last tracked coordinate in the set, then draw a line to the current x and yctx.moveTo( this.coordinates[ this.coordinates.length - 1][ 0 ], this.coordinates[ this.coordinates.length - 1][ 1 ] );ctx.lineTo( this.x, this.y );ctx.strokeStyle = 'hsl(' + hue + ', 100%, ' + this.brightness + '%)';ctx.stroke();ctx.beginPath();// draw the target for this firework with a pulsing circlectx.arc( this.tx, this.ty, this.targetRadius, 0, Math.PI * 2 );ctx.stroke();
}// create particle
function Particle( x, y ) {this.x = x;this.y = y;// track the past coordinates of each particle to create a trail effect, increase the coordinate count to create more prominent trailsthis.coordinates = [];this.coordinateCount = 5;while( this.coordinateCount-- ) {this.coordinates.push( [ this.x, this.y ] );}// set a random angle in all possible directions, in radiansthis.angle = random( 0, Math.PI * 2 );this.speed = random( 1, 10 );// friction will slow the particle downthis.friction = 0.95;// gravity will be applied and pull the particle downthis.gravity = 1;// set the hue to a random number +-20 of the overall hue variablethis.hue = random( hue - 20, hue + 20 );this.brightness = random( 50, 80 );this.alpha = 1;// set how fast the particle fades outthis.decay = random( 0.015, 0.03 );
}// update particle
Particle.prototype.update = function( index ) {// remove last item in coordinates arraythis.coordinates.pop();// add current coordinates to the start of the arraythis.coordinates.unshift( [ this.x, this.y ] );// slow down the particlethis.speed *= this.friction;// apply velocitythis.x += Math.cos( this.angle ) * this.speed;this.y += Math.sin( this.angle ) * this.speed + this.gravity;// fade out the particlethis.alpha -= this.decay;// remove the particle once the alpha is low enough, based on the passed in indexif( this.alpha <= this.decay ) {particles.splice( index, 1 );}
}// draw particle
Particle.prototype.draw = function() {ctx. beginPath();// move to the last tracked coordinates in the set, then draw a line to the current x and yctx.moveTo( this.coordinates[ this.coordinates.length - 1 ][ 0 ], this.coordinates[ this.coordinates.length - 1 ][ 1 ] );ctx.lineTo( this.x, this.y );ctx.strokeStyle = 'hsla(' + this.hue + ', 100%, ' + this.brightness + '%, ' + this.alpha + ')';ctx.stroke();
}// create particle group/explosion
function createParticles( x, y ) {// increase the particle count for a bigger explosion, beware of the canvas performance hit with the increased particles thoughvar particleCount = 30;while( particleCount-- ) {particles.push( new Particle( x, y ) );}
}// main demo loop
function loop() {// this function will run endlessly with requestAnimationFramerequestAnimFrame( loop );// increase the hue to get different colored fireworks over timehue += 0.5;// normally, clearRect() would be used to clear the canvas// we want to create a trailing effect though// setting the composite operation to destination-out will allow us to clear the canvas at a specific opacity, rather than wiping it entirelyctx.globalCompositeOperation = 'destination-out';// decrease the alpha property to create more prominent trailsctx.fillStyle = 'rgba(0, 0, 0, 0.5)';ctx.fillRect( 0, 0, cw, ch );// change the composite operation back to our main mode// lighter creates bright highlight points as the fireworks and particles overlap each otherctx.globalCompositeOperation = 'lighter';// loop over each firework, draw it, update itvar i = fireworks.length;while( i-- ) {fireworks[ i ].draw();fireworks[ i ].update( i );}// loop over each particle, draw it, update itvar i = particles.length;while( i-- ) {particles[ i ].draw();particles[ i ].update( i );}// launch fireworks automatically to random coordinates, when the mouse isn't downif( timerTick >= timerTotal ) {if( !mousedown ) {// start the firework at the bottom middle of the screen, then set the random target coordinates, the random y coordinates will be set within the range of the top half of the screenfireworks.push( new Firework( cw / 2, ch, random( 0, cw ), random( 0, ch / 2 ) ) );timerTick = 0;}} else {timerTick++;}// limit the rate at which fireworks get launched when mouse is downif( limiterTick >= limiterTotal ) {if( mousedown ) {// start the firework at the bottom middle of the screen, then set the current mouse coordinates as the targetfireworks.push( new Firework( cw / 2, ch, mx, my ) );limiterTick = 0;}} else {limiterTick++;}
}// mouse event bindings
// update the mouse coordinates on mousemove
canvas.addEventListener( 'mousemove', function( e ) {mx = e.pageX - canvas.offsetLeft;my = e.pageY - canvas.offsetTop;
});// toggle mousedown state and prevent canvas from being selected
canvas.addEventListener( 'mousedown', function( e ) {e.preventDefault();mousedown = true;
});canvas.addEventListener( 'mouseup', function( e ) {e.preventDefault();mousedown = false;
});// once the window loads, we are ready for some fireworks!
window.onload = loop;
</script>
<audio autoplay="autoplay">
<source src="http://www.sypeiyin.cn/Uploads/zh/News/2012071516257FJR.mp3" type="audio/mpeg">
</audio>
<img src="yanhua.jpg" width="380" height="120">
<img src="http://img.tongji.linezing.com/3455448/tongji.gif" />项目地址：https://download.csdn.net/download/Highning0007/88481855
![【C++】STL容器——探究不同 [ 迭代器 ] 种类＆在STL中的使用方式（15）](https://img-blog.csdnimg.cn/2a05d2bd2f7647228151b2630a568bb8.png)
![【蓝桥每日一题]-前缀和与差分（保姆级教程 篇3）#涂国旗 #重新排序](https://img-blog.csdnimg.cn/a9fe4a31c8dd48ae948fd7ea4ebf4c01.png)
