Mac/Linux builds don't support -fvisibility=hidden

[wayne-arnold-adsk]

the use of PTEXAPI could be expanded to include both Mac and Linux builds with use of:

__attribute__ ((visibility("default")))

#if defined(_WIN32) || defined(_WINDOWS) || defined(_MSC_VER)
# ifndef PTEXAPI
#  ifndef PTEX_STATIC
#    ifdef PTEX_EXPORTS
#       define PTEXAPI __declspec(dllexport)
#    else
#       define PTEXAPI __declspec(dllimport)
#    endif
#  else
#    define PTEXAPI
#  endif
# endif
#else
#  ifndef PTEXAPI
#    define PTEXAPI  __attribute__ ((visibility("default")))
#  endif
#  ifndef DOXYGEN
#    define PTEX_USE_STDSTRING
#  endif
#endif

[davvid]

CMake has a built-in way to generate export headers:

https://cmake.org/cmake/help/latest/module/GenerateExportHeader.html

Building upon that feature seems like a good way to go. 👍 thanks Wayne, this would be good to do.

[davvid]

Thanks Wayne, I think we have this working in https://github.com/wdas/ptex/pull/57

Could you please try out my visibilty branch from git://github.com/davvid/ptex.git and let me know if that looks good to you?

Thanks for the sug!

[wayne-arnold-adsk]

in reviewing the current code for Mac/Linux one would normally use the same

define PTEXAPI attribute ((visibility("default")))

for both cases, when defined PTEX_EXPORTS or not. else this can lead to different visibility warnings for different compile units