direct2D图片处理

转自：http://blog.csdn.net/augusdi/article/details/9040177

 Using Bitmap Brushes

Direct2D 中的图片处理增加了很多的灵活的特性，现在的Direct2D可以很好的和GUI,GUI+以及Direct3D混合使用，它支持更多的图形格式，更丰富的绘制方法。使用Direct2D绘制的win7程序，显示效果更好，绘制速度更快。 

LRESULT InItD2D(HWND hWnd)
{
    //创建一个Direct2D资源指针
     HRESULT hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &pD2DFactory);
     CoInitialize(NULL);

     hr = CoCreateInstance(
        CLSID_WICImagingFactory,
        NULL,
        CLSCTX_INPROC_SERVER,
        IID_PPV_ARGS(&p_pImageFactory)
        );
     if(SUCCEEDED(hr))
    {
        // Create a DirectWrite factory.
        hr = DWriteCreateFactory(
            DWRITE_FACTORY_TYPE_SHARED,
            __uuidof(p_pDWriteFactory),
            reinterpret_cast<IUnknown **>(&p_pDWriteFactory)
            );
    }

    if (SUCCEEDED(hr))
    {
        // Create a DirectWrite text format object.
        hr = p_pDWriteFactory->CreateTextFormat(
            L"微软雅黑",
            NULL,
            DWRITE_FONT_WEIGHT_DEMI_BOLD,
            DWRITE_FONT_STYLE_NORMAL,
            DWRITE_FONT_STRETCH_ULTRA_EXPANDED,
            24,
            L"MyFont", //locale
            &p_pText
            );
    }

    if (SUCCEEDED(hr))
    {
        // Center the text horizontally and vertically.
        p_pText->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_CENTER);

        p_pText->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_CENTER);
    }
    // Obtain the size of the drawing area.
    GetClientRect(hWnd, &rc);

    // Create a Direct2D render target
    hr = pD2DFactory->CreateHwndRenderTarget(D2D1::RenderTargetProperties(),
                                             D2D1::HwndRenderTargetProperties(hWnd,D2D1::SizeU(rc.right - rc.left, rc.bottom - rc.top)),
                                            &p_pRenderTarget);

    //从资源中载入一张图片
    //LoadResourceBitmap(p_pRenderTarget,   p_pImageFactory,MAKEINTRESOURCE(IDR_JPG1),L"jpg",&p_pBitmap);

    //从硬盘上载入一张图片
    LoadBitmapFromFile(p_pRenderTarget,p_pImageFactory,L"car.jpg",0,0,&p_pBitmap);

    // 设置笔刷
    if (SUCCEEDED(hr))
    {
        p_pRenderTarget->CreateSolidColorBrush(D2D1::ColorF(D2D1::ColorF::Black),&p_pBlackBrush);
        p_pRenderTarget->CreateBitmapBrush(  p_pBitmap ,&p_pBitmapBrush  );
    }

    return hr;
}

其中IWICImagingFactory类提供了一个高效的图形绘制接口

hr = CoCreateInstance(
       CLSID_WICImagingFactory,
       NULL,
       CLSCTX_INPROC_SERVER,
       IID_PPV_ARGS(&p_pImageFactory)
       );

 还有两个函数LoadResourceBitmap()和LoadBitmapFromFile()都是载入图片的函数，这两个函数可以载入我们常见的图片格式，要研究这一块的内容，估计一时半会说不明白，微软现在已经通过类似于控件的方式提供了多种图片的载入方式，目前直接支持的有jpg,bmp,gif,png等。还可以按照自己的解析器来完成自己需要图片格式的读写~ 

VOID Render()
{
    if(!p_pRenderTarget)
        return ;

    static const WCHAR szBitmapBrushText[] = L"图片笔刷";

    // Define the shape of rectangles to be filled with brushes.
    D2D1_RECT_F rcBrushRect = D2D1::RectF(0, 0, 470, 613);

    // Define the area where captions are drawn.
    D2D1_RECT_F rcTextRect = D2D1::RectF(0, 1065, 450, 200);

    p_pRenderTarget->BeginDraw();
    p_pRenderTarget->SetTransform(D2D1::Matrix3x2F::Identity());

    p_pRenderTarget->Clear(D2D1::ColorF(D2D1::ColorF::White));

    // Translate for the bitmap brush.
    p_pRenderTarget-