利用jquery判断点是否在椭圆内

提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

源码例子下载：

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>画椭圆</title>
<style>
.title{text-align:center;}
.wrapper{margin: 0 auto;width: 500px; margin: 0 auto;border: 1px solid #000000;}
.content{position: relative;height: 500px;}
.dot{position: absolute;width:1px;height: 1px;overflow: hidden;font-size:0;line-height: 0; background: #333;}
</style>
</head>
<body>
<h1 class="title">画一个椭圆并判断点击是否在椭圆内</h1>
<div class="wrapper">
<div class="content" id="content">
</div></div>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js"></script>
<script>
//*********定义加载模块方法 start **************//
(function (window, undefined) {
if (window.define) {
return
}
function isFunction(obj) {
return Object.prototype.toString.call(obj) === "[object Function]"
} var MM = {};
var initModuleName = "initRun"; function require(name) {
if (!MM[name]) {
throw new Error("Module " + name + " is not defined.")
}
var module = MM[name];
if (module.inited === false) {
runModule(name)
}
return module.ret
} function runModule(name) {
var exports = {};
var module = MM[name];
if (isFunction(MM[name].factory)) {
var ret = MM[name].factory.apply(undefined, [require, exports, undefined]);
module.ret = ret === undefined ? exports : ret
} else {
module.ret = MM[name].factory
}
module.inited = true
} function define(name, deps, factory) {
if (MM[name]) {
throw new Error("Module " + name + " has been defined already.")
}
if (isFunction(deps)) {
factory = deps
}
MM[name] = {factory:factory, inited:false};
if (name === initModuleName) {
runModule(name)
}
} window.define = define
})(window);
//*********定义加载模块方法 end **************// /**
* @author ruby
* @despretion 画椭圆并判断点击是否在椭圆内
* @return
*/
(function(){
/**
* @dec 可以进行缓存的节点
* @type {Object}
*/
var $dom = {
content : $('#content')
}
/**
* @despretion定义画椭圆函数
*/
define('mode/drawEliplse',function(require){
var ElipObj ={
draw : function(el,a,b){
var dotHtmlArr = [],//储存画点的 html元素
leftStyle , rightStyle; //左右的样式值
var widthEl = el && el[0].offsetWidth ,
heightEl = el && el[0].offsetHeight; for(var i = 0; i < 360;i++){
leftStyle = (a*Math.sin(i) + (widthEl-2)/2) + "px";
rightStyle = (b*Math.cos(i) + (heightEl-2)/2) + "px"; dotHtmlArr.push('<div class="dot" style="left:' +
leftStyle+';top:'+rightStyle+'"></div>');
} el.html(dotHtmlArr.join("")); }
,
/**
* @desc 判断点击是否在椭圆内算法在椭圆内点左边点带入后值小于1
* @param a 椭圆长
* @param b 椭圆宽
* @param x 鼠标x坐标
* @param y 鼠标y坐标
* @parm true 在椭圆内 false 不在椭圆内
*/
prove : function(a,b,x,y){
return Math.pow((x/a),2) + Math.pow((y/b),2) < 1 ? true : false;
}
}
return ElipObj;
});
/**
* @desc需要进行绑定的事件
*/
define('view/bindFun',function(require){
var drawMode = require("mode/drawEliplse"); $dom.content.bind('click',function(e){
if (e.pageX || e.pageY) {
var x = e.pageX,
y = e.pageY;
} else {
var x = e.clientX + document.body.scrollLeft - document.body.clientLeft,
y = e.clientY + document.body.scrollTop - document.body.clientTop;
} var offsetX = $(this).offset().left,
offsetY = $(this).offset().top; //鼠标所在点位置相对与中心点
x = x - offsetX - ($(this)[0].offsetWidth -2)/2;
y = y - offsetY - ($(this)[0].offsetHeight -2)/2; if( drawMode.prove(100,80,x,y) ){
alert("点击在椭圆内");
} }); });
/**
* @desc 模块启动函数
*/
define('initRun',function(require){
var drawMode = require("mode/drawEliplse"); drawMode.draw($dom.content,100,80);
require("view/bindFun"); }) })()
</script>
</body>
</html>