Updated game structure

CMakeLists.txt

@@ -22,14 +22,16 @@ find_package(SDL3_ttf CONFIG REQUIRED)
 
 add_executable(tetris
     src/main.cpp
-    src/Game.cpp
-    src/Scores.cpp
-    src/Starfield.cpp
-    src/Starfield3D.cpp
-    src/Font.cpp
-    src/Audio.cpp
-    src/LineEffect.cpp
-    src/SoundEffect.cpp
+    src/gameplay/Game.cpp
+    src/core/GravityManager.cpp
+    src/core/StateManager.cpp
+    src/persistence/Scores.cpp
+    src/graphics/Starfield.cpp
+    src/graphics/Starfield3D.cpp
+    src/graphics/Font.cpp
+    src/audio/Audio.cpp
+    src/gameplay/LineEffect.cpp
+    src/audio/SoundEffect.cpp
     # State implementations (new)
     src/states/LoadingState.cpp
     src/states/MenuState.cpp
@@ -73,4 +75,30 @@ if (WIN32)
 endif()
 
 # Include production build configuration
-include(cmake/ProductionBuild.cmake)
+include(cmake/ProductionBuild.cmake)
+
+# Enable CTest so `add_test` registers tests for `ctest`
+enable_testing()
+
+# Unit tests (simple runner)
+find_package(Catch2 CONFIG REQUIRED)
+add_executable(tetris_tests
+    tests/GravityTests.cpp
+    src/core/GravityManager.cpp
+)
+target_include_directories(tetris_tests PRIVATE ${CMAKE_SOURCE_DIR}/src)
+target_link_libraries(tetris_tests PRIVATE Catch2::Catch2WithMain)
+add_test(NAME GravityTests COMMAND tetris_tests)
+
+if(EXISTS "${CMAKE_SOURCE_DIR}/vcpkg_installed/x64-windows/include")
+    target_include_directories(tetris_tests PRIVATE "${CMAKE_SOURCE_DIR}/vcpkg_installed/x64-windows/include")
+endif()
+
+# Add new src subfolders to include path so old #includes continue to work
+target_include_directories(tetris PRIVATE
+    ${CMAKE_SOURCE_DIR}/src
+    ${CMAKE_SOURCE_DIR}/src/audio
+    ${CMAKE_SOURCE_DIR}/src/gameplay
+    ${CMAKE_SOURCE_DIR}/src/graphics
+    ${CMAKE_SOURCE_DIR}/src/persistence
+)