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
Fixes for clamp-omp, fewer shared variables, fix some cases of threads writing
to the same memory location. Issue found by Jens Verwiebe, who reports 30%
speedup with 16 core CPU, when using this with a recent clang-omp version.
This mainly touches extern libraries and few debug-only places in intern.
Some summary:
- External libraries are not strict at all about missing declarations,
so we can rather safely remove such warning together with other strict
flags.
- Bullet has some static functions which are not used.
Those were commented out.
- Carve now has some unused debug-only functions commented out as well.
While we're on the way of getting rid of Carve, it makes sense to make
things a bit cleaner for the time being.
- In LZMA we have some parts disabled which gives some set but unused
variables which is rather correct.
- Elbeem had quite some variables set and never used because their usage
is inside of debug-only code which is commented out.
Note about patching upstream libraries: surely one might say that we
have to make local patchset against this, but own experience says it
only gives extra work trying to merge such tweaks to a new upstream
version and usually it's just faster to re-apply such fixes again after
bundling new upstream library.
While SCons building system was serving us really good for ages it's no longer
having much attention by the developers and started to become quite a difficult
task to maintain.
What's even worse -- there started to be quite serious divergence between SCons
and CMake which was only accumulating over the releases now. The fact that none
of the active developers are really using SCons and that our main studio is also
using CMake spotting bugs in the SCons builds became quite a difficult task and
we aren't always spotting them in time.
Meanwhile CMake became really mature building system which is available on every
platform we support and arguably it's also easier and more robust to use.
This commit includes:
- Removal of actual SCons building system
- Removal of SCons git submodule
- Removal of documentation which is stored in the sources and covers SCons
- Tweaks to the buildbot master to stop using SCons submodule
(this change requires deploying to the server)
- Tweaks to the install dependencies script to skip installing or mentioning
SCons building system
- Tweaks to various helper scripts to avoid mention of SCons folders/files
as well
Reviewers: mont29, dingto, dfelinto, lukastoenne, lukasstockner97, brecht, Severin, merwin, aligorith, psy-fi, campbellbarton, juicyfruit
Reviewed By: campbellbarton, juicyfruit
Differential Revision: https://developer.blender.org/D1680
Changes for VC2013
Now, I can build Blender with VC2013 with Cycles, Collada, OpenExr,OpenImageIO disabled. Also, you need VC2008 sp1 installed to make old libs compatible.
Global OpenMP threads override is not a good idea because this would affect
all possible OpenMP blocks running at the same time as simulation.
And that was actually a big on restoring number of threads: code needed to
store current number of threads, not maximal one.
Also fix:
- Fluid simulation was always lagging 1 frame behind: E.g. the 250th frame in blender showed 249th frame of the fluid simulation.
Change:
- Animated enabled/disabled property only gets counted as "on" if value >= 1
Note that this bugfix should solve many problems with timings of animated fluid sim properties.
Remark: I think that "!(nbored & CFBnd)" would be correct but it introduced other bugs so, I just quiet compiler warnings leaving the running system untouched.
Note: Supporting obstacles which can be enabled/disabled as animated propoerty is not likely to happen. So I marked this as "Won't fix"/TODO.
I also reverted last commit on this bug because it didn't work and disabled the property from UI to avoid confusion.
