created holes for tetrahedralize(::Mesh, ...)

[chakravala]

see issue #17

[codecov-commenter]

Codecov Report

Merging #18 (b4f6630) into master (9b94238) will increase coverage by 7.30%.
The diff coverage is 90.73%.

❗ Current head b4f6630 differs from pull request most recent head 2d96bd0. Consider uploading reports for the commit 2d96bd0 to get more accurate results

@@            Coverage Diff             @@
##           master      #18      +/-   ##
==========================================
+ Coverage   80.19%   87.50%   +7.30%     
==========================================
  Files           4        6       +2     
  Lines         101      368     +267     
==========================================
+ Hits           81      322     +241     
- Misses         20       46      +26     

Impacted Files	Coverage Δ
src/TetGen.jl	100.00% <ø> (ø)
src/rawtetgenio.jl	89.65% <89.65%> (ø)
src/jltetgenio.jl	78.50% <92.85%> (ø)
src/cpptetgenio.jl	94.73% <94.73%> (ø)
src/api.jl	100.00% <100.00%> (+25.00%)	⬆️
src/meshes.jl	100.00% <100.00%> (ø)

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[SimonDanisch]

Thank you!
Do you have some code handy to test this?

[SimonDanisch]

Yeah hard to tell if it works without a test ;) I don't really know tetgen very well... Tagging @j-fu for a review!

[j-fu]

Essentially, this repo contains two APIs for TetGen, one which is based on GeometryBasics.Mesh which AFAIU does not convey all possibilities of TetGen. I added another API (after your PR) which is essentially array based (very much like that for Triangulate.jl). It is not hard for me to provide a hole example for this one, and from there you can see how to make a hole example for the mesh based API.

[SimonDanisch]

GeometryBasics.Mesh which AFAIU does not convey all possibilities of TetGen

Which cases are those?

[j-fu]

Hi, just pushed an example how to serve the TetGen API:

TetGen.jl/examples/examples.jl

Line 49 in b4f6630

function cubewithhole(;vol=1)

One needs to create subregion encircled by facets an put a "holepoint" into it.
See also http://wias-berlin.de/software/tetgen/1.5/doc/manual/manual006.html#ff_poly
and https://juliageometry.github.io/TetGen.jl/stable/#TetGen.RawTetGenIO

[j-fu]

GeometryBasics.Mesh which AFAIU does not convey all possibilities of TetGen

Which cases are those?
May I miss something due to insufficient knowledge how to work with the mesh struct so please correct me on that:
What comes into my mind in addition to holes:

• different cell region markers: instead of a hole point I can place a "region point" and spread its marker (and a maximal volume) to a whole subregion, creating some integer "cell meta" on output, very much like boundary facet markers
• local refinement via callback (but this of course wouldn't go into the Mesh API I think it already now could be used together with it)

[j-fu]

Will add a test example after merge.

[SimonDanisch]

Alright, thanks :)