Tweaks and instructions for a workable windows build

[AtheMathmo]

Resolves #12

[sgsellan]

@bathal1 , this is to make the python bindings compilable in windows. Would you mind checking that they are not broken in linux/Mac systems by adding this?

[bathal1]

The dllimport and dllexport flags are Windows-specific, and this PR currently breaks the build on Linux. Please modify your changes to only use these flags on windows using this macro:

#if defined(_MSC_VER)
#  define BOTSCH_EXPORT(__declspec(dllexport))
#else
#  define BOTSCH_EXPORT
#endif

[AtheMathmo]

I've added the macro and tested that the windows build goes through okay. In doing so, I've potentially shown my hand as not-really-a-c++-developer. Feel free to make changes directly or advise me on how to modify the source.

P.S. If you're familiar with windows build systems, any idea how to have cmake produce remesh as a static library instead of dynamic? Right now this needs to be changed manually.

Edit: What I mean is that visual studio seems to want remesh to be a static library; the remeshmesh project seeks a .lib instead of the .dll that is produced. Can you safely change remesh to a static library on the linux build? Or do we need to modify remeshmesh to seek the dynamic library instead?

[bathal1]

Thanks. You can switch to a static library by changing the SHARED keyword in CMakeLists.txt:26 to STATIC. Why do you need to change this?

[AtheMathmo]

As a dynamic library I get the following error when trying to build on windows

I'm not sure if it is environment specific or more general.

[mworchel]

Hi, I've encountered the same issues as @AtheMathmo some months ago and I've been successfully using a static build of the library on Linux and Windows for quite some time.

Now after some quick googling, adding this seems to be the actual fix for building the shared library with CMake >= 3.4:

set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)

EDIT: Also, instead of having a separate install section for each OS, it's probably better to just use the cmake commands:

# Use `Debug` instead of `Release` for debug builds
cmake . -B build -DCMAKE_BUILD_TYPE=Release 
cmake --build build --config Release --parallel