老师，关于旋转有点不懂，谢谢

来源：4-3 Canvas图形变换之旋转和缩放

qq_慕移动3101913

2020-02-28 15:41:49

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>canvasL</title>
    <style>
        canvas {
            background-color: lightblue;
        }
    </style>
</head>

<body>
    <canvas id="canvas" width="600px" height="600px">您的浏览器不支持</canvas>
    <script>
        // 获取元素
        var canvas = document.getElementById('canvas');
        var ctx = canvas.getContext('2d');

    //rotate 旋转变换
      ctx.rotate(Math.PI/6);
      ctx.moveTo(200,200);
      ctx.lineTo(400,400);
      ctx.lineWidth = 5;
      ctx.strokeStyle = "#F00";
      ctx.stroke();

    </script>
</body>

</html>

未进行旋转时：