<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>加速度-行星</title>
    <link rel="stylesheet" href="style/pub.css">
    <style>
        canvas {
            border: 1px solid #000;
            display: block;
            background-color: #000;
        }
    </style>
</head>

<body>
    <canvas width="800" height="600"></canvas>
    <script src="util/utils.js"></script>
    <script src="class/ship.js"></script>
    <script>
        (function () {
            var canvas =