feat: 实现 D3D12SwapChain 交换链类

- 添加 D3D12SwapChain.h 头文件
- 实现 IDXGISwapChain3 封装
- 实现 Initialize、Present、Resize 等方法
- 测试通过

engine/src/RHI/D3D12SwapChain.cpp

@@ -0,0 +1,75 @@
+#include "XCEngine/RHI/D3D12/D3D12SwapChain.h"
+
+namespace XCEngine {
+namespace RHI {
+
+D3D12SwapChain::D3D12SwapChain()
+    : m_windowHandle(nullptr)
+    , m_width(0)
+    , m_height(0)
+    , m_bufferCount(2) {
+}
+
+D3D12SwapChain::~D3D12SwapChain() {
+    Shutdown();
+}
+
+bool D3D12SwapChain::Initialize(IDXGIFactory4* factory, ID3D12CommandQueue* commandQueue, HWND windowHandle, uint32_t width, uint32_t height, uint32_t bufferCount) {
+    DXGI_SWAP_CHAIN_DESC swapChainDesc = {};
+    swapChainDesc.BufferCount = bufferCount;
+    swapChainDesc.BufferDesc.Width = width;
+    swapChainDesc.BufferDesc.Height = height;
+    swapChainDesc.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_DISCARD;
+    swapChainDesc.OutputWindow = windowHandle;
+    swapChainDesc.SampleDesc.Count = 1;
+    swapChainDesc.SampleDesc.Quality = 0;
+    swapChainDesc.Windowed = TRUE;
+
+    IDXGISwapChain* swapChain = nullptr;
+    HRESULT hResult = factory->CreateSwapChain(commandQueue, &swapChainDesc, &swapChain);
+    if (FAILED(hResult)) {
+        return false;
+    }
+
+    hResult = swapChain->QueryInterface(IID_PPV_ARGS(&m_swapChain));
+    if (FAILED(hResult)) {
+        return false;
+    }
+
+    m_commandQueue = commandQueue;
+    m_windowHandle = windowHandle;
+    m_width = width;
+    m_height = height;
+    m_bufferCount = bufferCount;
+
+    return true;
+}
+
+void D3D12SwapChain::Shutdown() {
+    m_swapChain.Reset();
+}
+
+uint32_t D3D12SwapChain::GetCurrentBackBufferIndex() const {
+    return m_swapChain->GetCurrentBackBufferIndex();
+}
+
+ID3D12Resource* D3D12SwapChain::GetBackBuffer(uint32_t index) const {
+    ID3D12Resource* resource = nullptr;
+    m_swapChain->GetBuffer(index, IID_PPV_ARGS(&resource));
+    return resource;
+}
+
+void D3D12SwapChain::Present(uint32_t syncInterval, uint32_t flags) {
+    m_swapChain->Present(syncInterval, flags);
+}
+
+void D3D12SwapChain::Resize(uint32_t width, uint32_t height) {
+    m_swapChain->ResizeBuffers(m_bufferCount, width, height, DXGI_FORMAT_R8G8B8A8_UNORM, 0);
+    m_width = width;
+    m_height = height;
+}
+
+} // namespace RHI
+} // namespace XCEngine