Windows only problems

[VectorWolf]

Compilation Problems

• CMake can't properly locate SDL2. Tested workarounds don't help. Currently it has to be done manually which is lots of needless work.
• Visual Studio demands a _tmain entry point although a plain main should theoretically suffice.
• The Visual Studio compiler complains a lot and needs many additional includes where normally forward declarations suffice.
• The gcc specific CXX_FLAGS specified in CMake obviously make the Visual Studio compiler choke.
• There are probably some wrong project properties set by Cmake, but concrete errors couldn't be isolated yet.

Performance Problems

• Every 1 - 2 seconds the window noticeably jumps/stutters for one frame. (Works properly in Wine)
• When/After dragging the window the textures of the objectlayer/all actors suddenly disappear. Also sound doesn't play anymore. (Works properly in Wine)

[VectorWolf]

All but the performance problems were solved:

• CMake now uses more platform independent find_package calls
• The windows dependencies are now pack in another repo linked as a submodule
• The issue with the main function is solved via a preprocessor directive
• The issues with the msvc compiler were solved by using gcc/g++ via mingw-w64