feat: lighting system (directional + point light)

- lighting.h/c: Light struct, create_dir, create_point
- light_test.c: Lambert diffuse shader demo
- light_data CB not yet connected (needs fix)

CMakeLists.txt

@@ -24,6 +24,7 @@ set(ENGINE_SOURCES
     Engine/Rendering/mesh.c
     Engine/Rendering/texture.c
     Engine/Rendering/camera.c
+    Engine/Rendering/lighting.c
     Engine/Scene/scene_graph.c
     Engine/ECS/world.c
     Engine/Input/input.c
@@ -70,3 +71,7 @@ set_target_properties(ly_interpreter PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE
 add_executable(scene_test WIN32 Demo/game_test.c)
 target_link_libraries(scene_test Engine d3d11 dxgi d3dcompiler ole32 oleaut32 uuid gdi32 user32 kernel32 winmm)
 set_target_properties(scene_test PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/build ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/build)
+
+add_executable(light_test WIN32 Demo/light_test.c)
+target_link_libraries(light_test Engine d3d11 dxgi d3dcompiler ole32 oleaut32 uuid gdi32 user32 kernel32 winmm)
+set_target_properties(light_test PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/build ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/build)