The Issue
=======
For a long time now MinGW has been unsupported and unmaintained and at this point,
it looks like something that we should just leave behind and move on.
Why Remove
==========
One of the big motivations for MinGW back in the day is that it was free compared to MSVC which was licensed based.
However, now that this is no longer true we have basically stopped updating the need CMake files.
Along with the CMake files, there are several patches to the extern libs needed to make this work. For example, see:
https://developer.blender.org/diffusion/B/browse/master/extern/carve/patches/mingw_w64.patch
If we wanted to keep MinGW then we would need to make more custom patches to the external libs and
this is not something our platform maintainers are willing to do.
For example, here is the patches needed to build python: https://github.com/Alexpux/MINGW-packages/tree/master/mingw-w64-python3
Fixes T51301
Differential Revision: https://developer.blender.org/D2648
TexFace complicates the now more popular shading pipeline by having
per-face images, see: T51382 for details.
To keep the ability to select a per-material edit-image
(used with UV-mapping workflow), the material now stores an image
which will be set when changing images in edit-mode.
This is used as a bake-target when not using Cycles too.
We have callbacks for that, they also do some checks and help ensure things are done
correctly. Only place where this is assumed not true is blenloader (since here we
may affect refcount of library IDs as well...).
This is mandatory for incoming custom normal imports from io scripts, because
often geometry here is corrupted, so we need to call mesh.validate() to clean it up.
Issue is, we cannot set custom normals before geometry is clean, so we need to store
temporary plain loop normals in a CD_NORMAL layer, validate, and then set custom normals.
So we need a way to prevent 'temp' lnors to be freed by validate.
- add missing headers from cmake (own omission)
- quiet rna_test.c unused define warnings.
- minor style edits
- spelling corrections and ignore all uppercase words with spell checking script.
