Project file hierarchy

minetest/src folders

cguitfont - Freetype font stuff
json -
jthread
lua - include a Lua 5.1 implementation
script - both C++ to intialise Lua structures, and code to register C++ code as Lua functions. (E.g., script/scripting_mainmenu.cpp seems to be C++ code to invoke Lua fns defined in script/lua_api/l_mainmenu.cpp)
1. lua_api - (i) wrappers for C++ code to use in Lua scripts and via the Lua-C api (e.g., lua_api/l_server.cpp), and (ii) making simple game abstractions (e.g., lua_api/l_inventory.cpp)
2. cpp_api - seems to be C++ similar to and working with those (ii) for lua_api, except they use *the* global L Lua state object