核心知识点
- requestAnimationFrame
- 统计一秒内的frame次数
- fps → Frames Per Second
示例代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Stat</title>
<style>
.fps-panel {
background: #333;
color: #fff;
text-align: center;
width: 100px;
height: 120px;
line-height: 120px;
}
</style>
</head>
<body>
<div class="fps-panel" id="stat"></div>
<div contenteditable="true" style="overflow:hidden;margin-top:30px; width:400px;height: 200px;border: 1px #333 solid;"/>
<script>
let beignTime;
let framesCount = 0;
let prevTime;
function runTestUI(){
}
function stat() {
beignTime = new Date().getTime();//启动时间
if (!prevTime) {
prevTime = beignTime;
}
//测试渲染的的代码
runTestUI();
framesCount++
if (new Date().getTime() - prevTime > 1000) {
document.getElementById('stat').innerHTML = framesCount;
framesCount = 0;
prevTime = new Date().getTime();
}
window.requestAnimationFrame(stat)
}
window.requestAnimationFrame(stat)
</script>
</body>
</html>
