Currently object bounds (`object.runtime.bb`) are lazily initialized
when accessed. This access happens from arbitrary threads, and
is unprotected by a mutex. This can cause access to stale data at
best, and crashes at worst. Eager calculation is meant to keep this
working, but it's fragile.
Since e8f4010611, geometry bounds are cached in the geometry
itself, which makes this object-level cache redundant. So, it's clearer
to build the `BoundBox` from those cached bounds and return it by
value, without interacting with the object's cached bounding box.
The code change is is mostly a move from `const BoundBox *` to
`std::optional<BoundBox>`. This is only one step of a larger change
described in #96968. Followup steps would include switching to
a simpler and smaller `Bounds` type, removing redundant object-
level access, and eventually removing `object.runtime.bb`.
Access of bounds from the object for mesh, curves, and point cloud
objects should now be thread-safe. Other object types still lazily
initialize the object `BoundBox` cache since they don't have
a data-level cache.
Pull Request: https://projects.blender.org/blender/blender/pulls/113465
Using ClangBuildAnalyzer on the whole Blender build, it was pointing
out that BLI_math.h is the heaviest "header hub" (i.e. non tiny file
that is included a lot).
However, there's very little (actually zero) source files in Blender
that need "all the math" (base, colors, vectors, matrices,
quaternions, intersection, interpolation, statistics, solvers and
time). A common use case is source files needing just vectors, or
just vectors & matrices, or just colors etc. Actually, 181 files
were including the whole math thing without needing it at all.
This change removes BLI_math.h completely, and instead in all the
places that need it, includes BLI_math_vector.h or BLI_math_color.h
and so on.
Change from that:
- BLI_math_color.h was included 1399 times -> now 408 (took 114.0sec
to parse -> now 36.3sec)
- BLI_simd.h 1403 -> 418 (109.7sec -> 34.9sec).
Full rebuild of Blender (Apple M1, Xcode, RelWithDebInfo) is not
affected much (342sec -> 334sec). Most of benefit would be when
someone's changing BLI_simd.h or BLI_math_color.h or similar files,
that now there's 3x fewer files result in a recompile.
Pull Request #110944
