https://developers.weixin.qq.com/miniprogram/dev/component/canvas.html

类似于2d情况下的官方示例代码如下，但在webgl情况下却没有相关示例该如何设置分辨率，能否告知该如何设置？谢谢

        const canvas = res[0].node
        const ctx = canvas.getContext('2d')        
        const dpr = wx.getSystemInfoSync().pixelRatio
        canvas.width = res[0].width * dpr
        canvas.height = res[0].height * dpr
        ctx.scale(dpr, dpr)