rewriting and organizing the code

engine/CMakeLists.txt

@@ -0,0 +1,25 @@
+cmake_minimum_required(VERSION 3.20)
+file(GLOB_RECURSE ENGINE_SOURCES "src/*.cpp")
+add_library(engine STATIC ${ENGINE_SOURCES})
+target_include_directories(engine PUBLIC
+        ${CMAKE_CURRENT_SOURCE_DIR}/include
+        ${CMAKE_CURRENT_SOURCE_DIR}/raylib/include
+        
+)
+
+set(ENGINE_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src")
+set(ENGINE_EXPORT_DIR "${CMAKE_CURRENT_SOURCE_DIR}/include")
+file(GLOB_RECURSE HEADER_FILES "${ENGINE_SRC_DIR}/*.h" "${ENGINE_SRC_DIR}/*.hpp")
+foreach(HEADER ${HEADER_FILES})
+    file(RELATIVE_PATH REL_PATH "${ENGINE_SRC_DIR}" "${HEADER}")
+
+    set(DEST "${ENGINE_EXPORT_DIR}/${REL_PATH}")
+
+    get_filename_component(DEST_DIR "${DEST}" DIRECTORY)
+
+    add_custom_command(
+            TARGET engine PRE_BUILD
+            COMMAND ${CMAKE_COMMAND} -E make_directory "${DEST_DIR}"
+            COMMAND ${CMAKE_COMMAND} -E copy_if_different "${HEADER}" "${DEST}"
+    )
+endforeach()