The mesh triangulation data is stored in CPU memory with the same format
as the triangles GPU index buffer. Because of that we can skip creating a
temporary copied owned by the GPU API. One way to do that is to just
upload the data directly and avoid keeping a reference to it. However, we
can only upload GPU data from the main thread with OpenGL, so instead
reference the data and keep track of whether to free it.
When drawing a mesh with a single material and 1.8 million faces, this
change gives a 12-15% improvement in framerate, from about 32 to 37 FPS.
Part of #116901.
Pull Request: https://projects.blender.org/blender/blender/pulls/122175
A continuation of #116901. This one doesn't have a performance impact
in my testing. It also adds a bit more code compared to main so it isn't
really obviously "better" like the previous refactors. However it does
get us closer to removing the "extractors" callback iteration loop
(`edit_data` is the only other enabled by default), and I'd argue that
the final code is easier to iterate on in the future since it's more
self-contained.
I made an effort to avoid storing restart indices in the index buffers.
Though this requires a bit more calculation on the CPU (particularly
because the hidden gaps in the IBO need to be compressed out), it
reduces overall CPU->GPU traffic and removes the need to strip the
restart indices on Metal.
Pull Request: https://projects.blender.org/blender/blender/pulls/122084
This PR is another step in the refactor described by #116901.
This change applies to the triangle index buffer. The main improvement
is the ability to recognize when the mesh corner triangles index array
can be uploaded directly (when there is a single material and no hidden
faces). In that case the index data should be copied directly to the
GPU rather than to a temporary array owned by the IBO first. Though
that isn't implemented yet since it will be handled by the GPU module
later, the code is now structured to make that change simple from the
data extraction perspective.
Other than that, the main change is to not use the extractor iterator
framework anymore, and to set index data directly instead of using GPU
API functions. Though we're mainly bottlenecked by memory-bandwidth
anyway, it's nice to avoid function call overhead.
We also now avoid creating the array of sorted triangle indices when
there is a single material and no hidden faces. And we don't use
restart indices for the single-material case anymore. For Metal that's
nice because we can avoid `strip_restart_indices`.
I didn't notice significant performance improvements in my test files
beyond a few percent here and there. With a hacked implementation of
the copy-directly-to-the-gpu optimization, I did see more consistent
improvements though.
Pull Request: https://projects.blender.org/blender/blender/pulls/119130
Now that all relevant code is C++, the indirection from the C struct
`GPUVertBuf` to the C++ `blender::gpu::VertBuf` class just adds
complexity and necessitates a wrapper API, making more cleanups like
use of RAII or other C++ types more difficult.
This commit replaces the C wrapper structs with direct use of the
vertex and index buffer base classes. In C++ we can choose which parts
of a class are private, so we don't risk exposing too many
implementation details here.
Pull Request: https://projects.blender.org/blender/blender/pulls/119825
