Created by: yishanchuan

前端异常如下：

Uncaught (in promise) TypeError: Cannot read property 'RGBA' of null
    at new t (index.js:1)
    at new t (index.js:1)
    at new t (index.js:1)
    at t.value (index.js:1)
    at t.<anonymous> (index.js:1)
    at u (index.js:1)
    at Generator._invoke (index.js:1)
    at Generator.forEach.t.(:8888/anonymous function) [as next] (https://localhost:8888/gesture.77a0a3b8.js:122:4238)
    at n (index.js:1)
    at s (index.js:1)

定位到代码错误在

进一步查找到，

//gl = canvas.getContext('webgl2') || canvas.getContext('experimental-webgl2');
    gl = canvas.getContext('webgl') || canvas.getContext('experimental-webgl');

我替换为webgl2，也无法解决这个问题