direct2d图像刚性弯曲代码

以下是使用 Direct2D 实现图像刚性弯曲的示例代码：

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

#pragma comment(lib, "d2d1.lib")
#pragma comment(lib, "windowscodecs.lib")

// 定义图像刚性变换的矩阵
D2D1_MATRIX_3X2_F g_transformMatrix = D2D1::Matrix3x2F(1, 0, 0, 0, 1, 0);

// 定义 Direct2D 绘图对象
ID2D1Factory* g_pD2DFactory = nullptr;
ID2D1HwndRenderTarget* g_pRenderTarget = nullptr;
ID2D1Bitmap* g_pBitmap = nullptr;
ID2D1BitmapBrush* g_pBitmapBrush = nullptr;

// 定义窗口大小
const int g_width = 800;
const int g_height = 600;

// 加载位图文件
HRESULT LoadBitmapFromFile(ID2D1RenderTarget* pRenderTarget, IWICImagingFactory* pIWICFactory, LPCWSTR uri, UINT destinationWidth, UINT destinationHeight, ID2D1Bitmap** ppBitmap)
{
    HRESULT hr = S_OK;

    // 创建 WIC 图像解码器
    IWICBitmapDecoder* pDecoder = nullptr;
    hr = pIWICFactory->CreateDecoderFromFilename(uri, nullptr, GENERIC_READ, WICDecodeMetadataCacheOnLoad, &pDecoder);
    if (SUCCEEDED(hr))
    {
        // 读取位图帧
        IWICBitmapFrameDecode* pSource = nullptr;
        hr = pDecoder->GetFrame(0, &pSource);
        if (SUCCEEDED(hr))
        {
            // 缩放位图
            IWICBitmapScaler* pScaler = nullptr;
            hr = pIWICFactory->CreateBitmapScaler(&pScaler);
            if (SUCCEEDED(hr))
            {
                UINT originalWidth = 0;
                UINT originalHeight = 0;
                hr = pSource->GetSize(&originalWidth, &originalHeight);
                if (SUCCEEDED(hr))
                {
                    FLOAT scaleX = static_cast<FLOAT>(destinationWidth) / originalWidth;
                    FLOAT scaleY = static_cast<FLOAT>(destinationHeight) / originalHeight;

                    WICPixelFormatGUID pixelFormat;
                    hr = pSource->GetPixelFormat(&pixelFormat);
                    if (SUCCEEDED(hr))
                    {
                        if (scaleX != 1.0f || scaleY != 1.0f)
                        {
                            pScaler->Initialize(pSource, static_cast<UINT>(destinationWidth), static_cast<UINT>(destinationHeight), WICBitmapInterpolationModeCubic);
                            pRenderTarget->CreateBitmapFromWicBitmap(pScaler, nullptr, ppBitmap);
                        }
                        else
                        {
                            pRenderTarget->CreateBitmapFromWicBitmap(pSource, nullptr, ppBitmap);
                        }
                    }
                }
                pScaler->Release();
            }
            pSource->Release();
        }
        pDecoder->Release();
    }
    return hr;
}

// 初始化 Direct2D
HRESULT InitializeDirect2D(HWND hWnd)
{
    HRESULT hr = S_OK;

    // 创建 Direct2D 工厂
    hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &g_pD2DFactory);
    if (SUCCEEDED(hr))
    {
        // 获取窗口大小
        RECT rc;
        GetClientRect(hWnd, &rc);
        D2D1_SIZE_U size = D2D1::SizeU(rc.right - rc.left, rc.bottom - rc.top);

        // 创建 Direct2D 渲染目标
        hr = g_pD2DFactory->CreateHwndRenderTarget(D2D1::RenderTargetProperties(), D2D1::HwndRenderTargetProperties(hWnd, size), &g_pRenderTarget);
        if (SUCCEEDED(hr))
        {
            // 加载位图文件
            IWICImagingFactory* pIWICFactory = nullptr;
            hr = CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pIWICFactory));
            if (SUCCEEDED(hr))
            {
                hr = LoadBitmapFromFile(g_pRenderTarget, pIWICFactory, L"test.jpg", g_width, g_height, &g_pBitmap);
                if (SUCCEEDED(hr))
                {
                    // 创建位图画刷
                    hr = g_pRenderTarget->CreateBitmapBrush(g_pBitmap, &g_pBitmapBrush);
                    if (SUCCEEDED(hr))
                    {
                        // 设置画刷的平铺模式为重复
                        g_pBitmapBrush->SetExtendModeX(D2D1_EXTEND_MODE_WRAP);
                        g_pBitmapBrush->SetExtendModeY(D2D1_EXTEND_MODE_WRAP);
                    }
                }
                pIWICFactory->Release();
            }
        }
    }
    return hr;
}

// 渲染场景
void RenderScene()
{
    // 开始渲染
    g_pRenderTarget->BeginDraw();

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

    // 应用刚性变换矩阵
    g_pRenderTarget->SetTransform(g_transformMatrix);

    // 绘制位图
    g_pRenderTarget->FillRectangle(D2D1::RectF(0, 0, g_width, g_height), g_pBitmapBrush);

    // 结束渲染
    g_pRenderTarget->EndDraw();
}

// 释放资源
void ReleaseResources()
{
    SafeRelease(&g_pD2DFactory);
    SafeRelease(&g_pRenderTarget);
    SafeRelease(&g_pBitmap);
    SafeRelease(&g_pBitmapBrush);
}

// 处理窗口消息
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_CREATE:
        // 初始化 Direct2D
        if (FAILED(InitializeDirect2D(hWnd)))
        {
            MessageBox(hWnd, L"初始化 Direct2D 失败", L"错误", MB_OK | MB_ICONERROR);
            return -1;
        }
        break;
    case WM_PAINT:
        // 渲染场景
        RenderScene();
        ValidateRect(hWnd, NULL);
        break;
    case WM_SIZE:
        // 重新创建渲染目标
        ReleaseResources();
        if (FAILED(InitializeDirect2D(hWnd)))
        {
            MessageBox(hWnd, L"初始化 Direct2D 失败", L"错误", MB_OK | MB_ICONERROR);
            return -1;
        }
        break;
    case WM_DESTROY:
        // 释放资源
        ReleaseResources();
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// WinMain 函数
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // 注册窗口类
    WNDCLASSEX wcex = { sizeof(WNDCLASSEX) };
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.hInstance = hInstance;
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.lpszClassName = L"Direct2DApp";
    RegisterClassEx(&wcex);

    // 创建窗口
    HWND hWnd = CreateWindow(L"Direct2DApp", L"Direct2D App", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, g_width, g_height, NULL, NULL, hInstance, NULL);
    if (!hWnd)
    {
        return FALSE;
    }

    // 显示窗口
    ShowWindow(hWnd, nCmdShow);

    // 消息循环
    MSG msg = {};
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return (int)msg.wParam;
}

在上面的示例代码中，`g_transformMatrix` 变量表示图像的刚性变换矩阵，可以使用 `D2D1::Matrix3x2F` 函数来创建。在 `RenderScene` 函数中，可以使用 `g_pRenderTarget->SetTransform` 函数来应用刚性变换矩阵。