Fire Plague,
When you open op2editor in Visual Studio again, look in the filter (virtual folder) 'source code'. You will find op2editor is included in the project. That is the 'main' file. op2editor.cpp contains the main function for the library, posted below. I compiled this using VS2017 I think about a year ago, so it can be done. It relies on COM to talk with the op2mapper frontend that was written in an older version of Visual Basic.
// DLL Entry Point
extern "C"
BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID /*lpReserved*/)
{
if (dwReason == DLL_PROCESS_ATTACH)
{
g_hInstance = hInstance;
DisableThreadLibraryCalls(hInstance);
}
return TRUE; // ok
}
If you want to compile, post the errors you are getting and I'll see if I can help.
However, we pulled many sections of code out of op2editor and incorporated them into OP2Utility. In the process we removed COM, started using C++11 or newer language features, and removed all dependencies on windows specific libraries. OP2utility can be used on Windows or Linux and compiled against x86 or x64. So I would recommend using OP2Utility for archive access, loading maps, unpacking sprites (this is partially implemented), etc. Not sure what you are trying to accomplish though.
op2editor has remained abandoned because no one in the community is taking the time to update the front-end (requiring experience in Visual Basic) or has a real skillset in COM. Although an update to the op2mapper would be a boon to the community at some point.
Hope that helps.
-Brett