adding third party libs and defining some early API headers

third_party/CMakeLists.txt

@@ -0,0 +1,16 @@
+file(GLOB LUA_SOURCES CONFIGURE_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/lua/*.c)
+list(FILTER LUA_SOURCES EXCLUDE REGEX "/(lua|luac)\\.c$")
+
+add_library(lua STATIC ${LUA_SOURCES})
+target_include_directories(lua SYSTEM PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/lua)
+set_target_properties(lua PROPERTIES C_STANDARD 99 C_EXTENSIONS ON)
+if(UNIX)
+  target_compile_definitions(lua PRIVATE LUA_USE_POSIX)
+  target_link_libraries(lua PUBLIC m)
+endif()
+
+add_library(clay INTERFACE)
+target_include_directories(clay SYSTEM INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/clay)
+
+add_library(stb INTERFACE)
+target_include_directories(stb SYSTEM INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/stb)