Blender Git Loki

Change boolean blenlib interface to be purely C++.

Change bmesh_boolean.c into a C++ file and start using PolyMesh interface.

Also, use BLI_math_mpq.hh everywhere instead of gmpxx.h.

Fix problem after master merge with Optional -> optional migration.

On Mac, there's an error re using the value() member of std::optional.
Working around it for now.

Merge branch 'master' into newboolean

Dissolving triangulation edges and verts passes first test.

First test with dissolve of triangulation edges is passing.

Still lots to do. And this includes a horribly inefficient way
of finding which edges are dissolvable -- to be fixed later.

Merge branch 'master' into newboolean

Continued work on getting triangulation edges removed from output.

Merge branch 'master' into newboolean

Start of PolyMesh interface for boolean.

Also refactored delaunay to put the 2d mesh representation into
an externally visible CDTArrangement class. Not sure yet whether
I will use this; if I end up not using it, will move that part of
the header back into the implementation file.

Fixed bug for some binary boolean ops. Fixed a memory leak.

Now the basic binary booleans work from the tool (not the modifier).
Still to do: (1) coplanar and non-connected-component cases;
(2) dissolve triangulation lines and new verts due only to them;
(3) properly transfer mesh attributes from old to new;
(4) hook up to modifier;
(5) attention to and tuning of performance.

Made binary version of boolean and hooked up to Boolean tool.

Union seems to work. Other ops are flaky because I haven't
quite got the winding number propagation right yet.

More boolean tests pass.

Fixed bug re confusion of how to sort triangles around an edge.
Fixed bug in first tettet test (inconsistent normals in input).

Proper implementation of finding ambient cell.

Also fixed bug in boolean test where passed wrong output
to the obj writer.

First real boolean union output test works.

Quient some warnings on Linux.

After merge from master, updated for changes to BLI.

Mainly namespace changes, BLI -> blender, so I changed my
own namespaces to follow that pattern.
ArrayRef -> Span.
Now can have hash() as member of data structures rather
that having to make a DefaultHash for them.
Fixed a bad assumption about Arrays of bool being initialized to false.

Merge branch 'master' into newboolean

Format previous commit.

A lot of progress towards working boolean library function.

The code to partition space into cells is mostly done.
The code to propagate winding numbers and flag cells according to the
boolean function is mostly done.
Only final extraction code is left, and a few other things.