<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
body{
overflow: hidden;
}
</style>
<body>
<canvas id="view" width="" height=""></canvas>
</body>
<script type="text/javascript">
//1.初始化获取元素
var canvas = document.getElementById('view');
var ps = canvas.getContext('2d');
//2.获取窗口可视区域宽高
var width = document.documentElement.clientWidth;
var height = document.documentElement.clientHeight;
//3.更新canvas宽高
canvas.width = width;
canvas.height = height;
//4.定义构造函数
function ball(title){
//初始化xy坐标还有半径
this.r = 15;
this.x = this.random(width-this.r);
this.y = this.random(height-this.r);
//初始化颜色
this.color = this.randomColor();
//初始化移动速度
this.speedX = this.random(4);
this.speedY = this.random(6);
//初始化文本
this.title = title || 'Canvas';
}
//5.添加原型方法
ball.prototype = {
random:function(num){
return parseInt(Math.random()*num)+1
},
randomColor:function(){
return 'rgb('+this.random(255)+','+this.random(255)+','+this.random(255)+')'
},
move:function(){
this.x += this.speedX;
this.y += this.speedY;
if(this.x < this.r ){
this.speedX = Math.abs(this.speedX)
}else if(this.x > width-this.r){
this.speedX = -this.speedX
}
if(this.y < this.r ){
this.speedY = Math.abs(this.speedY)
}else if(this.y > height-this.r){
this.speedY = -this.speedY
}
this.render();
},
render:function(){
ps.beginPath();
ps.fillStyle = this.color;
ps.arc(this.x,this.y,this.r,0,2*Math.PI);
ps.fill();
this.fillText();
},
fillText:function(){
ps.font = '16px 微软雅黑';
ps.fillText(this.title,this.x+this.r+2,this.y+this.r/2-2);
}
}
//单独给ball函数添加属性或方法
ball.children = [];
ball.running = 0;
ball.init = function(list){
//拆分成数组
list = list.split(/\s+/);
//遍历数组并创建对应的球
for(var i = 0; i<list.length; i++){
// 将实例化的球添加到children中 并且指定文本
this.children.push(new this(list[i]))// this就是ball
}
}
ball.play = function(){
//如果已运行返回
if(this.running) return;
this.running = 1;
var children = this.children;
setInterval(function(){
ps.clearRect(0,0,width,height);
//遍历子元素执行move方法
for(var i = 0; i<children.length; i++){
//执行move方法
children[i].move();
// 遍历所有子元素挨个比较计算距离
for(var j = 0; j<children.length;j++){
//i==j时不比较 因为是同一个球
if(i!=j){
//计算两个球之间的距离
var left = children[i].x - children[j].x;
var top1 = children[i].y - children[j].y;
//取绝对值
// left = Math.abs(left);
top1 = Math.abs(top1);
//限制距离 在100-200之间可以连线
if(left<0 && left>=-200 && top1<=200){
//从当前球画到 另一个
ps.beginPath();
ps.strokeStyle = children[i].color;
ps.moveTo(children[i].x,children[i].y);
ps.lineTo(children[j].x,children[j].y);
ps.stroke();
}
}
}
}
},30);
}
ball.init('Html Css Javascript Jquery Css Javascript Jquery Css Javascript Jquery Css Javascript Jquery PHP Mysql XML Ajax JSONP Cavnas BigPipe Memached Redis CSS3 HTML5');
ball.play();
//var obj = new ball();
</script>
</html>
