7becc38a3c introduced new text rendering.
In the refactoring the vertex buffer was replaced by a more shallow
storage buffer. However the refactoring removed one optimization that
the vulkan backend uses, namely the actual amount of bytes that is being
used by the draw call. This resulted in overly large data transfers.
For example in the text editor the texts are rendered one glyph at a
time. But the storage buffer would always upload the data for 1024
glyphs.
This PR allows the usage size of a storage buffer to be set to ensure
that the data transfers are limited.
The implementation wasn't added to OpenGL as it draws incorrectly.
Issue detected during the research of !146956 That PR will implement
better data streaming inside the Vulkan backend and also requires
to know the actual usage size of the buffer to detect what data can
be grouped together.
Pull Request: https://projects.blender.org/blender/blender/pulls/146958
a0370d2fe3