WIP: extend nglib api

[dyollb]

This is work in progress. I am still in the process of testing the api. The api changes are backwards compatible, i.e. new arguments are optional. Please feel free to comment, or give suggestions.

new features:

• expose domain index
• expose mesh optimization parameters
• expose "STL mesh doctor" parameters
• expose 2D geometries / 2D meshing
• export meshes to VTK file format (2D/3D, including domain index)
• options to make netgen quiet (send messages to null stream)

todo:

• expose bc index
• ... ?

[ChrLackner]

The api is quite old and I think it would be better/easier to just build against the C++ code. Is there a reason why you do not want that? Best Christopher

[dyollb]

@ChrLackner Do you mean I should directly link against ngcore, and directly use all the classes from the different parts of netgen, or would you use the nginterfaces.h interface instead? I don't think it supports all I need from nglib.h either.

I have for a long time been using the nglib interface with local modifications and wanted instead move those local changes to the main branch.

[ChrLackner]

Yes I would suggest linking against the c++ libraries. If you want you can write me at [email protected] and we can work out a stable interface that supports what you need, but we would like to not expand the nglib api. It provides a very small and stable api, but since we do not test, improve and maintain it (or at least as less as possible) we want to keep it small. If we expand it we would need to keep it up to date (which we do not really have the resources for) Best Christopher