to help with detecting "not changed" event when taking
Undo/Redo snapshot or synchronizing with the back-end.
Converted layer height profile and supports / seam painted areas
to the same timestamp controlled structure.
1) Fixed a wrong offset when extracting infill lines from the octree.
2) Added a variant for testing triangle in a bounding sphere
when buildind the octree. Currently not used as the box test
is more tight.
3) "Bridging infill" regions are now triangulated and used to densify
the octree as well to support the bridging infill correctly.
1) Octree is built directly from the triangle mesh by checking
overlap of a triangle with an octree cell. This shall produce
a tighter octree with less dense cells.
2) The same method is used for both the adaptive / support cubic infill,
where for the support cubic infill the non-overhang triangles are
ignored.
The AABB tree is no more used.
3) Optimized extraction of continuous infill lines in O(1) instead of O(n^2)
1) All slicer's exceptions are now derived from Slic3r::Exception.
2) New exceptions are defined for slicing errors.
3) Exceptions are propagated to the Plater to show.
It remains to modify the slicing back-end to throw the new SlicingError
exceptions instead of std::runtime_error and to show the other exceptions
by a message dialog instead of a notification.
The offset curve extractor is already quite usable,
though singular cases are still not covered yet
when the offset curve intersects or nearly intersects
a Voronoi vertex.
Removal of the PRINTF_ZU "%zu" Visual Studio printf compatibility macro.
Fixes of a contours self intersection test for collinear segments.
SVG exporter now exports white background, so that the GNOME Eye viewer is usable.
