Spring RTS Engine

ZK custom map texture is grainy and according to the comments this is caused by having no mipmap. So the solution is to generate a mipmap for the custom texture and there is a gl.GenerateMipmap callout which I wanted to use:
(actual code)

But this fails: the custom texture is applied but is still grainy. What could be wrong?

• gl.GenerateMipmap needs some GL extension. But I was able to call it - the call would be nil (and error out when called) if I didn't have the extension.
• the "!" denotes Lua textures and is expected by gl.GenerateMipmap so I don't think it's the problem either.
• swapping the order of the two callouts does nothing.

Thanks! Looks like the '!' is already contained in gl.CreateTexture return value.

However after taking this into account the code still does not work.

Look closely at https://springrts.com/wiki/Lua_ConstGL, then at what is (not) passed to glCreateTexture.

Passing this to glCreateTexture works. Thanks a lot!