Returning the pointer to the null byte when the character isn't found
is useful when handling null terminated strings that contain newlines.
This means the return value is never null and the line span always ends
at the resulting value.
When the loose edge and vertex status are cached in the source mesh and
the combination of selection domain and mode don't add loose elements,
copy the cache status to avoid recomputation. In a test with a 1 million
face grid:
- All: 23 -> 30 FPS
- Only faces: 22 -> 23.5 FPS
- Only edges and faces: 24 -> 27 FPS
Also remove unnecessary includes and fix a build error introduced in
the last commit to this area from an inconsistent forward declaration.
Replace the implementation of the separate and delete geometry nodes
for meshes. The new code makes more use of the `IndexMask` class, which
was recently optimized. The main goal is to make more of the work scale
with the size of the result mesh rather than the input. For example,
instead of keeping a map from input to output elements, the maps used
to copy attributes go from output to input elements.
The new implementation is generally 2-4x faster, depending on the mode
and the number of elements selected. The new code is also able to skip
more work when nothing is removed.
This also allows using more existing attribute interpolation code,
allowing the overall removal of over 300 lines. Some of the attribute
utilities from a similar change for curves (f63cfd8e28) are
reused directly.
The indices of the result changes, so the test file needs to be updated.
Pull Request: https://projects.blender.org/blender/blender/pulls/108435
IndexMask::complement() is often used in geometry processing
algorithms when a selection needs to be inverted, mostly just in
curves code so far.
Instead of reusing `from_predicate` and lookup in the source mask,
scan the mask once, inserting segments between the original indices.
Theoretically this improves the performance from O(N*log(N)) to O(N).
But with the small constant offset of the former, the improvement is
generally just 3-4 times faster. However in some cases like empty
and full masks, the new code takes constant time.
Pull Request: https://projects.blender.org/blender/blender/pulls/108331
A lot of files were missing copyright field in the header and
the Blender Foundation contributed to them in a sense of bug
fixing and general maintenance.
This change makes it explicit that those files are at least
partially copyrighted by the Blender Foundation.
Note that this does not make it so the Blender Foundation is
the only holder of the copyright in those files, and developers
who do not have a signed contract with the foundation still
hold the copyright as well.
Another aspect of this change is using SPDX format for the
header. We already used it for the license specification,
and now we state it for the copyright as well, following the
FAQ:
https://reuse.software/faq/
Avoid BLI_path_slash_rfind for accessing file-names as NULL is returned
when the path has no slashes, use BLI_path_basename instead.
Also remove 2 cases where BLI_path_basename was inlined.
When the new name was clipped to make room for the number,
the string was clipped by the number size (including the null byte).
Store the length in `numlen` instead of the size (including null byte).
The mask was sliced, but the original mask was used from before the
slicing, causing an unsliced mask to be used with the new offsets.
This caused a crash in the hair styles demo file.
Windows file associations using ProgID, needed because of the launcher.
This fixes "pin to taskbar" and Recent Documents lists, allow per-
version jump lists and an "Open with" list with multiple versions.
Pull Request: https://projects.blender.org/blender/blender/pulls/107013
Goals of this refactor:
* Reduce memory consumption of `IndexMask`. The old `IndexMask` uses an
`int64_t` for each index which is more than necessary in pretty much all
practical cases currently. Using `int32_t` might still become limiting
in the future in case we use this to index e.g. byte buffers larger than
a few gigabytes. We also don't want to template `IndexMask`, because
that would cause a split in the "ecosystem", or everything would have to
be implemented twice or templated.
* Allow for more multi-threading. The old `IndexMask` contains a single
array. This is generally good but has the problem that it is hard to fill
from multiple-threads when the final size is not known from the beginning.
This is commonly the case when e.g. converting an array of bool to an
index mask. Currently, this kind of code only runs on a single thread.
* Allow for efficient set operations like join, intersect and difference.
It should be possible to multi-thread those operations.
* It should be possible to iterate over an `IndexMask` very efficiently.
The most important part of that is to avoid all memory access when iterating
over continuous ranges. For some core nodes (e.g. math nodes), we generate
optimized code for the cases of irregular index masks and simple index ranges.
To achieve these goals, a few compromises had to made:
* Slicing of the mask (at specific indices) and random element access is
`O(log #indices)` now, but with a low constant factor. It should be possible
to split a mask into n approximately equally sized parts in `O(n)` though,
making the time per split `O(1)`.
* Using range-based for loops does not work well when iterating over a nested
data structure like the new `IndexMask`. Therefor, `foreach_*` functions with
callbacks have to be used. To avoid extra code complexity at the call site,
the `foreach_*` methods support multi-threading out of the box.
The new data structure splits an `IndexMask` into an arbitrary number of ordered
`IndexMaskSegment`. Each segment can contain at most `2^14 = 16384` indices. The
indices within a segment are stored as `int16_t`. Each segment has an additional
`int64_t` offset which allows storing arbitrary `int64_t` indices. This approach
has the main benefits that segments can be processed/constructed individually on
multiple threads without a serial bottleneck. Also it reduces the memory
requirements significantly.
For more details see comments in `BLI_index_mask.hh`.
I did a few tests to verify that the data structure generally improves
performance and does not cause regressions:
* Our field evaluation benchmarks take about as much as before. This is to be
expected because we already made sure that e.g. add node evaluation is
vectorized. The important thing here is to check that changes to the way we
iterate over the indices still allows for auto-vectorization.
* Memory usage by a mask is about 1/4 of what it was before in the average case.
That's mainly caused by the switch from `int64_t` to `int16_t` for indices.
In the worst case, the memory requirements can be larger when there are many
indices that are very far away. However, when they are far away from each other,
that indicates that there aren't many indices in total. In common cases, memory
usage can be way lower than 1/4 of before, because sub-ranges use static memory.
* For some more specific numbers I benchmarked `IndexMask::from_bools` in
`index_mask_from_selection` on 10.000.000 elements at various probabilities for
`true` at every index:
```
Probability Old New
0 4.6 ms 0.8 ms
0.001 5.1 ms 1.3 ms
0.2 8.4 ms 1.8 ms
0.5 15.3 ms 3.0 ms
0.8 20.1 ms 3.0 ms
0.999 25.1 ms 1.7 ms
1 13.5 ms 1.1 ms
```
Pull Request: https://projects.blender.org/blender/blender/pulls/104629
Combine the newer less efficient C++ implementations and the older
less convenient C functions. The maps now contain one large array of
indices, split into groups by a separate array of offset indices.
Though performance of creating the maps is relatively unchanged, the
new implementation uses 4 bytes less per source element than the C
maps, and 20 bytes less than the newer C++ functions (which also
had more overhead with larger N-gons). The usage syntax is simpler
than the C functions as well.
The reduced memory usage is helpful for when these maps are cached
in the near future. It will also allow sharing the offsets between
maps for different domains like vertex to corner and vertex to face.
A simple `GroupedSpan` class is introduced to make accessing the
topology maps much simpler. It combines offset indices and a separate
span, splitting it into chunks in an efficient way.
Pull Request: https://projects.blender.org/blender/blender/pulls/107861
Covers the macro ARRAY_SIZE() and STRNCPY.
The problem this change is aimed to solve it to provide cross-platform
compiler-independent safe way pf ensuring that the functions are used
correctly.
The type safety was only ensured for GCC and only for C. The C++
language and Clang compiler would not have detected issues of passing
bare pointer to neither of those macros.
Now the STRNCPY() will only accept a bounded array as the destination
argument, on any compiler.
The ARRAY_SIZE as well, but there are a bit more complications to it
in terms of transparency of the change.
In one place the ARRAY_SIZE was used on float3 type. This worked in the
old code because the type implements subscript operator, and the type
consists of 3 floats. One would argue this is somewhat hidden/implicit
behavior, which better be avoided. So an in-lined value of 3 is used now
there.
Another place is the ARRAY_SIZE used to define a bounded array of the
size which matches bounded array which is a member of a struct. While
the ARRAY_SIZE provides proper size in this case, the compiler does not
believe that the value is known at compile time and errors out with a
message that construction of variable-size arrays is not supported.
Solved by converting the field to std::array<> and adding dedicated
utility to get size of std::array at compile time. There might be a
better way of achieving the same result, or maybe the approach is
fine and just need to find a better place for such utility.
Surely, more macro from the BLI_string.h can be covered with the C++
inlined functions, but need to start somewhere.
There are also quite some changes to ensure the C linkage is not
enforced by code which includes the headers.
Pull Request: https://projects.blender.org/blender/blender/pulls/108041
This is necessary for correctness of the code to avoid duplicate symbols.
In practice, this wasn't necessary yet, because usually we pass lambdas
into these functions which cause every instantiation to have a different
signature.
Alignment here means that the size of the range passed into callback
is a multiple of the alignment value (which has to be a power of two).
This can help with performance when loops in the callback are are
unrolled and/or vectorized. Otherwise, it can potentially reduce
performance by splitting work into more unequally sized chunks.
For example, chunk sizes might be 4 and 8 instead of 6 and 6 when
alignment is 4.
