Finish lecture 82: Implement the World class

Signed-off-by: Daniel Henry <iamdanhenry@gmail.com>

CMakeLists.txt

@@ -8,6 +8,20 @@ set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFf)
 
+include(FetchContent)
+set(SFML_LIB_NAME SFML)
+
+FetchContent_Declare(
+	${SFML_LIB_NAME}
+	GIT_REPOSITORY https://github.com/SFML/SFML.git
+	GIT_TAG 2.6.0
+	GIT_SHALLOW FALSE
+)
+
+FetchContent_MakeAvailable(${SFML_LIB_NAME})
+
+set(LIGHT_YEARS_ENGINE_TARGET_NAME LightYearsEngine)
 set(LIGHT_YEARS_GAME_TARGET_NAME LightYearsGame)
 
-add_subdirectory(LightYears)
+add_subdirectory(LightYearsEngine)
+add_subdirectory(LightYearsGame)