[AD] Finding a solution to the Windows problem

[SiegeLord <siegelordex@xxxxxxxxxx>]

So as you guys are aware, Allegro has always had a bit of a Windows 
problem. Unlike all other platforms, there just isn't a standard method 
of building our dependencies or downloading them using a package 
manager. This is a bit of a problem, since despite the rise of mobile 
platforms (which comparatively are a lot easier to support, as both 
build upon Unix environments), Windows is still very popular.

So I want to figure out how we can produce binaries for it. One of the 
main difficulties is that this system must support MSVC, as it's just 
too (undeservedly, imo) popular. This rules out the simple solution of 
using mingw-w64 to cross compile everything from Linux. The mechanism we 
decide upon will probably have to run from Windows (perhaps with a msys 
shell). While it's relatively easy these days to build Allegro with 
mingw, MSVC is an incredible pain still (I tried a few weeks ago and 
gave up after a few hours). Ultimately, MSVC is the reason why we need 
to make these binaries available.

Another requirement is that one day, it'd be nice to have weekly or 
nightly builds. This will require a change in the build system, so this 
is a more of a future improvement type of thing that our chosen option 
hopefully doesn't rule out.

Here are some options I am considering:

- Don't distribute binaries, but instead work with mingw-w64's packagers 
(mingw-w64 only) and Nuget (MSVC only) package managers to provide 
Allegro packages. That only works if the necessary dependency packages 
are available on those platforms, so we might have to take upon 
ourselves to package some of the rarer dependencies (PhysFS and DUMB 
probably fall under this). Also, it's not clear how to deal with nightly 
builds. Lastly, mingw-w64, while being a great mingw distro, is not the 
only one people use... but it's the only one with a package manager 
worth its salt.

- Distribute binaries ourselves. This removes all the issues of 
packaging, but probably requires us to write our own build systems for a 
few of the dependencies (DUMB, libogg, libvorbis, libtheora come to 
mind). I envision adding a CMakeLists.txt to all of them for uniformity 
and MSVC compatibility.

- Figure out some way to make mingw-w64-produced binaries work with 
MSVC. This might be tricky, as we use quite a bit of C++ under 
Windows... but if it can be done, it'd simply things incredibly.

Any other ideas? I know Thomas was thinking of coming up with such a 
system, but as far as I know that never left the planning stage. It 
might be useful to use that hardware, perhaps, for nightly builds. It 
probably doesn't really matter for regular builds (assuming the system 
we come up with is automated enough to just-work on any Windows 
installation).

-SL