Volume transformations were ignored in SLA mode. This did not matter for plain STLs
and PS own 3MF, because in those cases, the volume trafo was identity. Importing
a 3rd party 3MF leads to issues with support/holes placement and generation.
Fixes#6100 and #6744.
TriangleMesh newly only holds indexed_triangle_set and
TriangleMeshStats. TriangleMeshStats contains an excerpt of stl_stats.
TriangleMeshStats are updated when initializing with indexed_triangle_set.
Admesh triangle mesh fixing is newly only used when loading an STL.
AMF / 3MF / OBJ file formats are already indexed triangle sets, thus
they are no more converted to admesh stl_file format, nor fixed
through admesh repair machinery. When importing AMF / 3MF / OBJ files,
volume is calculated and if negative, all faces are flipped. Also
a bounding box and number of open edges is calculated.
Implemented its_number_of_patches(), its_num_open_edges()
Optimized its_split(), its_is_splittable() using a visitor pattern.
Reworked QHull integration into TriangleMesh:
1) Face normals were not right.
2) Indexed triangle set is newly emitted instead of duplicating
vertices for each face.
Fixed cut_mesh(): Orient the triangulated faces correctly.
Drain holes reference position was saved slightly above the mesh to avoid problem when the hole is placed on flat or nearly flat surface
The depth of the hole was internally bigger than what the user has set to compensato for it
However, this leads to problem with scaling and makes reprojection of the holes on the mesh complicated
This commit changes the reference point to the point on the mesh and the extra elevation is handled when rendering and drilling the hole.
The change is reflected in 3MF drain holes versioning so that old 3MFs are loaded correctly.
Reprojection on the mesh after reload from disk/fix through netfabb has been enabled.
