feat: 实现D3D12 RHI抽象层，修复PSO创建问题

- 添加RHI接口定义(IRHIDevice, ICommandList, IResource等)
- 实现D3D12Device, D3D12CommandList, D3D12PipelineState等
- 修复RootSignature参数数量(3->4)与HelloEarth一致
- 修复DSV格式设置(Unknown->D24_UNorm_S8_UInt)
- 添加Geometry Shader编译
- 创建XCEngineDemo项目验证RHI功能

CMakeLists.txt

@@ -1,56 +1,10 @@
 cmake_minimum_required(VERSION 3.15)
-project(XCVolumeRenderer VERSION 1.0 LANGUAGES CXX)
+project(XCEngine)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
-set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
 
-set(SOURCES
-    main.cpp
-    BattleFireDirect.cpp
-    StaticMeshComponent.cpp
-    Utils.cpp
-    stbi/stb_image.cpp
-    NanoVDBLoader.cpp
-)
-
-set(HEADERS
-    BattleFireDirect.h
-    StaticMeshComponent.h
-    Utils.h
-    stbi/stb_image.h
-)
-
-add_executable(${PROJECT_NAME} WIN32 ${SOURCES} ${HEADERS})
-
-target_compile_definitions(${PROJECT_NAME} PRIVATE UNICODE _UNICODE)
-target_compile_options(${PROJECT_NAME} PRIVATE /utf-8 /MT)
-
-target_include_directories(${PROJECT_NAME} PRIVATE 
-    ${CMAKE_SOURCE_DIR}
-)
-
-target_link_libraries(${PROJECT_NAME} PRIVATE
-    d3d12.lib
-    dxgi.lib
-    d3dcompiler.lib
-    winmm.lib
-    kernel32.lib
-    user32.lib
-)
-
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    target_compile_definitions(${PROJECT_NAME} PRIVATE _DEBUG)
-else()
-    target_compile_definitions(${PROJECT_NAME} PRIVATE NDEBUG)
-endif()
-
-set_target_properties(${PROJECT_NAME} PROPERTIES
-    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}"
-)
-
-add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
-    COMMAND ${CMAKE_COMMAND} -E copy_directory
-    ${CMAKE_SOURCE_DIR}/Res
-    $<TARGET_FILE_DIR:${PROJECT_NAME}>/Res
-)
+add_subdirectory(engine)
+add_subdirectory(mvs/XCEngineDemo)
+add_subdirectory(mvs/HelloEarth)
+add_subdirectory(test)