部分代码可以删除

[tnqiang]

矩阵的加、减操作在渲染中用不到，可以考虑删除；

[emmanuel-deloget]

Hello,

Sorry if I answer in English, and hopefully Google Translate helped me to correctly understand the GH issue here (tanslation cames as "Matrix addition and subtraction operations are not used in rendering, you can consider deleting").

Please keep them, as if they are not present you'll force your users to re-implement them. Matrix substraction/addition may not be used during rendering, yet they may be used by a client application. Since the operation is trivial and the code is quite easy to read/check, it does no harm to keep it.

Best regards,

-- Emmanuel

[skywind3000]

They will be kept.