Well, guess why I was postponing this for so long, because there are way
too many combinations, then there's too many ways each variant can go
wrong, one has to document and test everything REAL GOOd and even then
it likely doesn't contain all variants people may want.
The shader requires the input data to be laid out in a rather specific
way, and there will be a dedicated MeshTools utility for it in the
following commits. For independence though, the shader tests use a
custom helper.
The initial implementation has certain corner cases which will be
eventually resolved. For now they are pinned down with repro cases in
the test. But apart from that, it's pretty much usable in practice.
Remaining join styles (round and miter-clip) as well as stipple support
will eventually follow as well.