feat(RHI): 添加 RHIFactory 工厂类

- 新增 RHIFactory 头文件和实现，支持通过 RHIType 或字符串创建设备
- 修复 D3D12Buffer 缺失的 Map/Unmap/SetData 实现
- 添加 RHI 工厂测试用例
- 更新 CMakeLists.txt 添加新文件

engine/src/RHI/D3D12/D3D12Buffer.cpp

@@ -155,5 +155,24 @@ void D3D12Buffer::UpdateData(const void* data, uint64_t size) {
     m_resource->Unmap(0, nullptr);
 }
 
+void* D3D12Buffer::Map() {
+    D3D12_RANGE readRange = { 0, 0 };
+    void* data = nullptr;
+    m_resource->Map(0, &readRange, &data);
+    return data;
+}
+
+void D3D12Buffer::Unmap() {
+    m_resource->Unmap(0, nullptr);
+}
+
+void D3D12Buffer::SetData(const void* data, size_t size, size_t offset) {
+    D3D12_RANGE writeRange = { offset, offset + size };
+    unsigned char* pBuffer = nullptr;
+    m_resource->Map(0, &writeRange, reinterpret_cast<void**>(&pBuffer));
+    memcpy(pBuffer + offset, data, size);
+    m_resource->Unmap(0, nullptr);
+}
+
 } // namespace RHI
 } // namespace XCEngine

engine/src/RHI/RHIFactory.cpp

@@ -0,0 +1,42 @@
+#include "XCEngine/RHI/RHIFactory.h"
+#include "XCEngine/RHI/D3D12/D3D12Device.h"
+
+namespace XCEngine {
+namespace RHI {
+
+RHIDevice* RHIFactory::CreateRHIDevice(RHIType type) {
+    switch (type) {
+        case RHIType::D3D12:
+            return new D3D12Device();
+        case RHIType::OpenGL:
+#ifdef XCENGINE_SUPPORT_OPENGL
+            {
+                #include "XCEngine/RHI/OpenGL/OpenGLDevice.h"
+                return new OpenGLDevice();
+            }
+#else
+            return nullptr;
+#endif
+        case RHIType::Vulkan:
+        case RHIType::Metal:
+        default:
+            return nullptr;
+    }
+}
+
+RHIDevice* RHIFactory::CreateRHIDevice(const std::string& typeName) {
+    if (typeName == "D3D12" || typeName == "d3d12") {
+        return new D3D12Device();
+    } else if (typeName == "OpenGL" || typeName == "opengl" || typeName == "GL") {
+#ifdef XCENGINE_SUPPORT_OPENGL
+        #include "XCEngine/RHI/OpenGL/OpenGLDevice.h"
+        return new OpenGLDevice();
+#else
+        return nullptr;
+#endif
+    }
+    return nullptr;
+}
+
+} // namespace RHI
+} // namespace XCEngine