#include <d2d1.h>
#include <d2d1helper.h>

// 初始化 Direct2D 和相关资源
HRESULT InitializeD2D(HWND hwnd, ID2D1Factory** ppFactory, ID2D1HwndRenderTarget** ppRenderTarget)
{
    // 创建 Direct2D 工厂
    HRESULT hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, ppFactory);
    if (SUCCEEDED(hr)) {
        RECT rc;
        GetClientRect(hwnd, &rc);

        // 创建 Direct2D 渲染目标
        hr = (*ppFactory)->CreateHwndRenderTarget(
            D2D1::RenderTargetProperties(),
            D2D1::HwndRenderTargetProperties(hwnd, D2D1::SizeU(rc.right - rc.left, rc.bottom - rc.top)),
            ppRenderTarget
        );
    }

    return hr;
}

// 绘制椭圆形
void DrawEllipse(ID2D1HwndRenderTarget* pRenderTarget)
{
    // 开始绘制
    pRenderTarget->BeginDraw();

    // 清空背景色
    pRenderTarget->Clear(D2D1::ColorF(D2D1::ColorF::White));

    // 创建椭圆形
    D2D1_ELLIPSE ellipse = D2D1::Ellipse(D2D1::Point2F(200.0f, 200.0f), 100.0f, 50.0f);

    // 设置椭圆形的笔刷颜色
    pRenderTarget->CreateSolidColorBrush(D2D1::ColorF(D2D1::ColorF::Blue), NULL, &pBrush);

    // 绘制椭圆形
    pRenderTarget->DrawEllipse(ellipse, pBrush);

    // 结束绘制
    pRenderTarget->EndDraw();
}

// 释放资源
void Cleanup(ID2D1Factory* pFactory, ID2D1HwndRenderTarget* pRenderTarget)
{
    if (pRenderTarget != NULL) {
        pRenderTarget->Release();
    }
    if (pFactory != NULL) {
        pFactory->Release();
    }
}

// 主窗口过程
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static ID2D1Factory* pFactory = NULL;
    static ID2D1HwndRenderTarget* pRenderTarget = NULL;

    switch (message) {
    case WM_CREATE:
        if (FAILED(InitializeD2D(hwnd, &pFactory, &pRenderTarget))) {
            return -1;  // 创建失败，结束窗口
        }
        return 0;

    case WM_PAINT:
        DrawEllipse(pRenderTarget);
        ValidateRect(hwnd, NULL);
        return 0;

    case WM_DESTROY:
        Cleanup(pFactory, pRenderTarget);
        PostQuitMessage(0);
        return 0;
    }

    return DefWindowProc(hwnd, message, wParam, lParam);
}

int main()
{
    // 窗口创建和消息循环代码...

    return 0;
}