Listing the "Blender Foundation" as copyright holder implied the Blender
Foundation holds copyright to files which may include work from many
developers.
While keeping copyright on headers makes sense for isolated libraries,
Blender's own code may be refactored or moved between files in a way
that makes the per file copyright holders less meaningful.
Copyright references to the "Blender Foundation" have been replaced with
"Blender Authors", with the exception of `./extern/` since these this
contains libraries which are more isolated, any changed to license
headers there can be handled on a case-by-case basis.
Some directories in `./intern/` have also been excluded:
- `./intern/cycles/` it's own `AUTHORS` file is planned.
- `./intern/opensubdiv/`.
An "AUTHORS" file has been added, using the chromium projects authors
file as a template.
Design task: #110784
Ref !110783.
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/
The goal is to solve confusion of the "All rights reserved" for licensing
code under an open-source license.
The phrase "All rights reserved" comes from a historical convention that
required this phrase for the copyright protection to apply. This convention
is no longer relevant.
However, even though the phrase has no meaning in establishing the copyright
it has not lost meaning in terms of licensing.
This change makes it so code under the Blender Foundation copyright does
not use "all rights reserved". This is also how the GPL license itself
states how to apply it to the source code:
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software ...
This change does not change copyright notice in cases when the copyright
is dual (BF and an author), or just an author of the code. It also does
mot change copyright which is inherited from NaN Holding BV as it needs
some further investigation about what is the proper way to handle it.
The goal is to make it easier to track down sources of errors during
the dependency graph builder.
With this change whenever a relation can not be added a trace to the
entity which requested the relation will be printed. For example:
```
Failed to add relation "Copy Location"
Could not find op_from: OperationKey(type: BONE, component name: 'MissingBone', operation code: BONE_DONE)
Trace:
Depth Type Name
----- ---- ----
1 Object Armature.001
2 Pose Channel Bone
3 Constraint Copy Location
```
On an implementation detail traced places where `checkIsBuiltAndTag`
is called, with some additional places to help tracking pose channels,
constraints, and modifiers.
Further improvements in granularity are possible, but that could happen
as a followup development once the core part is proven to work.
An example of such improvement would be to have entries in the trace
which will indicate NLA and drivers building. Currently it might be
a bit confusing to see IDs in the trace referenced from driver.
Even with such limitation the current state of the patch brings a
very valuable information (some information is much better than no
information at all).
Differential Revision: https://developer.blender.org/D15017
