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/
This contains the basis of the new overlay engine.
Only a few overlays are ported for proof of concept of the new design.
This new design unifies the selection drawing with the overlay-next engine.
It now becomes responsible of selection in object mode.
For this we create a dedicated shader module that patches the shaders
for selection.
Note that the gizmo selection still uses the occlusion queries and edit-mode
the current selection engine (select_engine.c).
Related task #102179
Related task #102177
Co-authored-by: Clément Foucault <foucault.clem@gmail.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/107734
