Setup CI for major supported platforms

[nbraud]

• Linux
• Windows
• macOS
• FreeBSD

Additional things to do:

• Matrix build SDL1/2
• Matrix build Clang vs. GCC
• Matrix build with/without GLM

[nbraud]

@jbeich Would you have any advise on getting Aquaria to build on FreeBSD?
I've look at the patches you put in the ports tree but didn't see anything obviously related; I assume the CMake config is wrong and somehow avoids looking at /usr/local/include for headers, and presumably /usr/local/lib to for libs)

[jbeich]

From FreeBSD CI log:

In file included from BBGE/Core.cpp:47:
/usr/local/include/SDL2/SDL_syswm.h:66:10: fatal error: 'X11/Xlib.h' file not found
#include <X11/Xlib.h>
         ^~~~~~~~~~~~

FindSDL2.cmake in Aquaria doesn't take into account SDL2 can have dependencies of its own e.g.,

$ pkg-config sdl2 --cflags
-I/usr/local/include/SDL2 -I/usr/local/include ...

FindSDL2.cmake in voxel-engine uses pkg-config but discards -I/usr/local/include in order to export singular SDL2_INCLUDE_DIR. :(

Downstream is not affected because it forces system libraries. -DAQUARIA_INTERNAL_PNG=OFF and -DAQUARIA_INTERNAL_FTGL=OFF do add -I/usr/local/include.

[nbraud]

@jbeich Thanks a lot for the tips! FreeBSD builds in CI are now green 💜

I'll have a look at building with Ninja and see whether that speed things up and such

[nbraud]

FWIW, TravisCI supports (undocumented) FreeBSD (only 12.1 atm) nowadays

Thanks, that's useful to know!

I'm not advocating to abandon CirrusCI

Yeah, the usability/reduced-magic advantages are definitely a big part of why I went with Cirrus, though it helps that it's AFAIK the only provider which supports all platforms Aquaria runs on, out of the box.