js 抛物线
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2024-03-25 12:46:52
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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
* {
margin: 0;
padding: 0;
}
.box {
width: 0px;
height: 0px;
margin-left: 500px;
margin-top: 500px;
position: relative;
}
.dian {
position: absolute;
width: 4px;
height: 4px;
margin-left: -2px;
margin-top: -2px;
border-radius: 50%;
background-color: red;
}
.row {
position: absolute;
left: 50%;
margin-left: -250px;
width: 500px;
height: 1px;
background-color: green;
}
.col {
position: absolute;
top: 50%;
margin-top: -250px;
width: 1px;
height: 500px;
background-color: green;
}
</style>
</head>
<body>
<div class="box">
<div class="row"></div>
<div class="col"></div>
<div class="dian"></div>
</div>
<script>
var x = -100
setInterval(function () {
x = x + 2;
var y = -x * x / 100 + x / 100 + 30;
var dian = document.querySelector('.dian');
dian.style.left = x + 'px';
dian.style.top = -y + 'px';
}, 10)
</script>
</body>
</html>