canvas实现的红包照片自适应效果-创新互联

效果图

公司主营业务：网站设计制作、成都网站设计、移动网站开发等业务。帮助企业客户真正实现互联网宣传，提高企业的竞争能力。成都创新互联是一支青春激扬、勤奋敬业、活力青春激扬、勤奋敬业、活力澎湃、和谐高效的团队。公司秉承以“开放、自由、严谨、自律”为核心的企业文化，感谢他们对我们的高要求，感谢他们从不同领域给我们带来的挑战，让我们激情的团队有机会用头脑与智慧不断的给客户带来惊喜。成都创新互联推出绥宁免费做网站回馈大家。

html结构(index.html)

 content=" height = device-height,

width = device-width,

initial-scale = 1.0,

minimum-scale = 1.0,

maximum-scale = 1.0,

user-scalable = no

" />

css样式(blur.css)

*{

margin: 0;

padding: 0;

}

#blur-div{

margin: 0 auto;

position: relative;

overflow: hidden;

}

#blur-image{

display: block;

margin: 0 auto;

filter:blur(20px);

-webkit-filter:blur(20px);

-moz-filter:blur(20px);

-ms-filter:blur(20px);

-o-filter:blur(20px);

position: absolute;

left: 0px;

top: 0px;

z-index: 0;

}

#blur-canvas{

display: block;

margin: 0 auto;

position: absolute;

left: 0px;

top: 0px;

z-index: 100;

}

.button{

display: block;

position: absolute;

z-index: 200;

width: 100px;

height: 30px;

color: white;

text-decoration: none;

text-align: center;

line-height: 30px;

border-radius: 5px;

}

#reset-button{

left: 50px;

bottom: 20px;

background-color: #058;

}

#reset-button:hover{

background-color: #047;

}

#show-button{

right: 100px;

bottom: 20px;

background-color: #085;

}

#show-button:hover{

background-color: #074;

}

js脚本(blur.js)

var canvasWidth = window.innerWidth;

var canvasHeight = window.innerHeight;

var canvasObj = document.getElementById("blur-canvas");

var contextObj = canvasObj.getContext("2d");

canvasObj.width = canvasWidth;

canvasObj.height = canvasHeight;

var imageObj = new Image();

var radius = 50;

var clippingRegion = {x:-1,y:-1,r:radius}

var leftMargin = 0,topMargin = 0;

imageObj.src = "20170122161717.png";

imageObj.onload = function(e){

$("#blur-div").css("width",canvasWidth+"px");

$("#blur-div").css("height",canvasHeight+"px");

$("#blur-image").css("width",imageObj.width+"px");

$("#blur-image").css("height",imageObj.height+"px");

leftMargin = (imageObj.width - canvasObj.width) / 2;

topMargin = (imageObj.height - canvasObj.height) / 2;

$("#blur-image").css("top",String(-topMargin)+"px");

$("#blur-image").css("left",String(-leftMargin)+"px");

initCanvas();

}

function initCanvas(){

var theleft = leftMargin < 0 ? -leftMargin:0;

var thetop = topMargin < 0 ? -topMargin:0;

var rx = Math.random()*(canvasObj.width - 2*radius-2*theleft)+radius+theleft;

var ry = Math.random()*(canvasObj.height - 2*radius-2*thetop)+radius+thetop;

clippingRegion = {x:rx,y:ry,r:radius};

drawImage(imageObj,clippingRegion);

}

function drawImage(imageObj,clippingRegion){

contextObj.clearRect(0,0,canvasObj.width,canvasObj.height);

contextObj.save();

setClippingRegion(clippingRegion);

// contextObj.drawImage(imageObj,0,0);

contextObj.drawImage(imageObj,Math.max(leftMargin,0),Math.max(topMargin,0),Math.min(canvasObj.width,imageObj.width),Math.min(canvasObj.height,imageObj.height),leftMargin < 0 ? -leftMargin:0,topMargin < 0 ? -topMargin:0,Math.min(canvasObj.width,imageObj.width),Math.min(canvasObj.height,imageObj.height));

contextObj.restore();

}

function setClippingRegion(clippingRegion){

contextObj.beginPath();

contextObj.arc(clippingRegion.x,clippingRegion.y,clippingRegion.r,0,Math.PI*2,false);

contextObj.clip();

}

function reset(){

initCanvas();

}

function show(){

document.getElementById("reset-button").style.display="none";

var animation = setInterval(function(){

clippingRegion.r += 20;

if (clippingRegion.r > 2*Math.max(canvasObj.width,canvasObj.height)) {

clearInterval(animation);

document.getElementById("reset-button").style.display="block";

}

drawImage(imageObj,clippingRegion);

},30);

}

canvasObj.addEventListener("touchstart",function(e){

e.preventDefault();

});

创新互联www.cdcxhl.cn，专业提供香港、美国云服务器，动态BGP最优骨干路由自动选择，持续稳定高效的网络助力业务部署。公司持有工信部办法的idc、isp许可证， 机房独有T级流量清洗系统配攻击溯源，准确进行流量调度，确保服务器高可用性。佳节活动现已开启，新人活动云服务器买多久送多久。

分享文章：canvas实现的红包照片自适应效果-创新互联
链接分享：http://www.wjwzjz.com/article/diieii.html