DOFs numberings displays

[camierjs]

This PR adds DOFs numbering.

The n key now cycles in 2D: NONE → ELEMENTS → EDGES → VERTICES → DOFS.

Should solve #106

Parallel numbering is now by default 'local' to each rank and can be toggled back to 'global' with Alt-n:

(mpirun -n 3 ./ex6p -m ../data/star-mixed.mesh -o 2 -md 200)

[tzanio]

To clarify: "DOF" here means the numbering of the Mesh nodes (as a high-order grid function), right?

[najlkin]

Js seems to be working: https://github.com/GLVis/glvis-js/actions/runs/15313952476 😉 Thanks for the cleanup 👍 I need to take a deeper look...

[najlkin]

I tested that and it works nicely with 2D scalars on conforming meshes, but a few things to do:

• update README
• update Changelog
• the current option could be written to console
• 2D vector grid functions do something strange after pressing N, should be fixed
• example 6 crashes glvis after switching to the second option, should be fixed

[najlkin]

@tzanio , it shows DOFs (in the sense of finite element nodes) for the visualized grid function. In the case of mesh visualization, the nodes of the coloring grid function.

[tzanio]

This is really great, thank you @camierjs !

[najlkin]

Looks good! 🎉

[tzanio]

Thank you so much @camierjs for adding this useful feature and @najlkin for the careful review! I am sure our users will appreciate it 🙏