直播app开发搭建，两种很简单的网页特效实现
一、星空
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>运营系统登录页</title>
<link href="static/css/login.css" rel="stylesheet" type="text/css">
<script type="text/javascript" src="static/lib/jquery/1.9.1/jquery.min.js"></script>
<script src="static/js/verificationNumbers.js" tppabs="static/js/verificationNumbers.js"></script>
<style>
.J_codeimg{z-index:-1;position:absolute;}
</style>
<script>
$(document).ready(function() {
//验证码
createCode();
});
</script>
</head>
<body>
<div id="demo">
</div>
<div> </div>
<canvas id="canvas"></canvas>
</div>
<script>
//宇宙特效
"use strict";
var canvas = document.getElementById('canvas'),
ctx = canvas.getContext('2d'),
w = canvas.width = window.innerWidth,
h = canvas.height = window.innerHeight,
hue = 217,
stars = [],
count = 0,
maxStars = 2500;//星星数量
var canvas2 = document.createElement('canvas'),
ctx2 = canvas2.getContext('2d');
canvas2.width = 100;
canvas2.height = 100;
var half = canvas2.width / 2,
gradient2 = ctx2.createRadialGradient(half, half, 0, half, half, half);
gradient2.addColorStop(0.025, '#CCC');
gradient2.addColorStop(0.1, 'hsl(' + hue + ', 61%, 33%)');
gradient2.addColorStop(0.25, 'hsl(' + hue + ', 64%, 6%)');
gradient2.addColorStop(1, 'transparent');
ctx2.fillStyle = gradient2;
ctx2.beginPath();
ctx2.arc(half, half, half, 0, Math.PI * 2);
ctx2.fill();
// End cache
function random(min, max) {
if (arguments.length < 2) {
max = min;
min = 0;
}
if (min > max) {
var hold = max;
max = min;
min = hold;
}
return Math.floor(Math.random() * (max - min + 1)) + min;
}
function maxOrbit(x, y) {
var max = Math.max(x, y),
diameter = Math.round(Math.sqrt(max * max + max * max));
return diameter / 2;
//星星移动范围，值越大范围越小，
}
var Star = function() {
this.orbitRadius = random(maxOrbit(w, h));
this.radius = random(60, this.orbitRadius) / 18;
//星星大小
this.orbitX = w / 2;
this.orbitY = h / 2;
this.timePassed = random(0, maxStars);
this.speed = random(this.orbitRadius) / 500000;
//星星移动速度
this.alpha = random(2, 10) / 10;
count++;
stars[count] = this;
}
Star.prototype.draw = function() {
var x = Math.sin(this.timePassed) * this.orbitRadius + this.orbitX,
y = Math.cos(this.timePassed) * this.orbitRadius + this.orbitY,
twinkle = random(10);
if (twinkle === 1 && this.alpha > 0) {
this.alpha -= 0.05;
} else if (twinkle === 2 && this.alpha < 1) {
this.alpha += 0.05;
}
ctx.globalAlpha = this.alpha;
ctx.drawImage(canvas2, x - this.radius / 2, y - this.radius / 2, this.radius, this.radius);
this.timePassed += this.speed;
}
for (var i = 0; i < maxStars; i++) {
new Star();
}
function animation() {
ctx.globalCompositeOperation = 'source-over';
ctx.globalAlpha = 0.5; //尾巴
ctx.fillStyle = 'hsla(' + hue + ', 64%, 6%, 2)';
ctx.fillRect(0, 0, w, h)
ctx.globalCompositeOperation = 'lighter';
for (var i = 1, l = stars.length; i < l; i++) {
stars[i].draw();
};
window.requestAnimationFrame(animation);
}
animation();
</script>
</body>
</html>
二、点击出现文字 特效
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
(function () {
var a_idx = 0;
window.onclick = function (event) {
var a = new Array("❤富强❤", "❤民主❤", "❤文明❤", "❤和谐❤", "❤自由❤", "❤平等❤", "❤公正❤", "❤法治❤", "❤爱国❤",
"❤敬业❤", "❤诚信❤", "❤友善❤");
var heart = document.createElement("b"); //创建b元素
heart.onselectstart = new Function('event.returnValue=false'); //防止拖动
document.body.appendChild(heart).innerHTML = a[a_idx]; //将b元素添加到页面上
a_idx = (a_idx + 1) % a.length;
heart.style.cssText = "position: fixed;left:-100%;"; //给p元素设置样式
var f = 16, // 字体大小
x = event.clientX - f / 2, // 横坐标
y = event.clientY - f, // 纵坐标
c = randomColor(), // 随机颜色
a = 1, // 透明度
s = 1.2; // 放大缩小
var timer = setInterval(function () { //添加定时器
if (a <= 0) {
document.body.removeChild(heart);
clearInterval(timer);
} else {
heart.style.cssText = "font-size:16px;cursor: default;position: fixed;color:" +
c + ";left:" + x + "px;top:" + y + "px;opacity:" + a + ";transform:scale(" +
s + ");";
y--;
a -= 0.016;
s += 0.002;
}
}, 15)
}
// 随机颜色
function randomColor() {
return "rgb(" + (~~(Math.random() * 255)) + "," + (~~(Math.random() * 255)) + "," + (~~(Math
.random() * 255)) + ")";
}
}());
</script>
</body>
</html>
以上就是直播app开发搭建，两种很简单的网页特效实现， 更多内容欢迎关注之后的文章
标签：function,特效,网页,max,app,random,half,var,Math From： https://www.cnblogs.com/yunbaomengnan/p/16824698.html