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.
These bits became obsolete with the new layer system, so we can
simplify some code around them or avoid existing workarounds which
were trying to keep things working for them.
There are still work needed to be done for on_visible_change to
avoid unnecessary updates, but that can also happen later.
Design Documents
----------------
* https://wiki.blender.org/index.php/Dev:2.8/Source/Layers
* https://wiki.blender.org/index.php/Dev:2.8/Source/DataDesignRevised
User Commit Log
---------------
* New Layer and Collection system to replace render layers and viewport layers.
* A layer is a set of collections of objects (and their drawing options) required for specific tasks.
* A collection is a set of objects, equivalent of the old layers in Blender. A collection can be shared across multiple layers.
* All Scenes have a master collection that all other collections are children of.
* New collection "context" tab (in Properties Editor)
* New temporary viewport "collections" panel to control per-collection
visibility
Missing User Features
---------------------
* Collection "Filter"
Option to add objects based on their names
* Collection Manager operators
The existing buttons are placeholders
* Collection Manager drawing
The editor main region is empty
* Collection Override
* Per-Collection engine settings
This will come as a separate commit, as part of the clay-engine branch
Dev Commit Log
--------------
* New DNA file (DNA_layer_types.h) with the new structs
We are replacing Base by a new extended Base while keeping it backward
compatible with some legacy settings (i.e., lay, flag_legacy).
Renamed all Base to BaseLegacy to make it clear the areas of code that
still need to be converted
Note: manual changes were required on - deg_builder_nodes.h, rna_object.c, KX_Light.cpp
* Unittesting for main syncronization requirements
- read, write, add/copy/remove objects, copy scene, collection
link/unlinking, context)
* New Editor: Collection Manager
Based on patch by Julian Eisel
This is extracted from the layer-manager branch. With the following changes:
- Renamed references of layer manager to collections manager
- I doesn't include the editors/space_collections/ draw and util files
- The drawing code itself will be implemented separately by Julian
* Base / Object:
A little note about them. Original Blender code would try to keep them
in sync through the code, juggling flags back and forth. This will now
be handled by Depsgraph, keeping Object and Bases more separated
throughout the non-rendering code.
Scene.base is being cleared in doversion, and the old viewport drawing
code was poorly converted to use the new bases while the new viewport
code doesn't get merged and replace the old one.
Python API Changes
------------------
```
- scene.layers
+ # no longer exists
- scene.objects
+ scene.scene_layers.active.objects
- scene.objects.active
+ scene.render_layers.active.objects.active
- bpy.context.scene.objects.link()
+ bpy.context.scene_collection.objects.link()
- bpy_extras.object_utils.object_data_add(context, obdata, operator=None, use_active_layer=True, name=None)
+ bpy_extras.object_utils.object_data_add(context, obdata, operator=None, name=None)
- bpy.context.object.select
+ bpy.context.object.select = True
+ bpy.context.object.select = False
+ bpy.context.object.select_get()
+ bpy.context.object.select_set(action='SELECT')
+ bpy.context.object.select_set(action='DESELECT')
-AddObjectHelper.layers
+ # no longer exists
```
Things like `BLI_uniquename` had nothing, but really nothing to do in
BLI_path_util files!
Also, got rid of length limitation in `BLI_uniquename_cb`, we can use
alloca here to avoid overhead of malloc while keeping free size (within
reasonable limits of course).
- Remove 'rotate_m2', unlike 'rotate_m4' it created a new matrix
duplicating 'angle_to_mat2' - now used instead.
(better avoid matching functions having different behavior).
- Add 'axis_angle_to_mat4_single',
convenience wrapper for 'axis_angle_to_mat3_single'.
- Replace 'unit_m4(), rotate_m4()' with a single call to 'axis_angle_to_mat4_single'.
