学步园

 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)<br /> {</p> <p> //创建一个Direct2D资源指针</p> <p> HRESULT hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &pD2DFactory);</p> <p> CoInitialize(NULL);</p> <p> hr = CoCreateInstance(<br /> CLSID_WICImagingFactory,<br /> NULL,<br /> CLSCTX_INPROC_SERVER,<br /> IID_PPV_ARGS(&p_pImageFactory)<br /> );</p> <p> if(SUCCEEDED(hr))<br /> {<br /> // Create a DirectWrite factory.<br /> hr = DWriteCreateFactory(<br /> DWRITE_FACTORY_TYPE_SHARED,<br /> __uuidof(p_pDWriteFactory),<br /> reinterpret_cast<IUnknown **>(&p_pDWriteFactory)<br /> );<br /> }</p> <p> if (SUCCEEDED(hr))<br /> {<br /> // Create a DirectWrite text format object.<br /> hr = p_pDWriteFactory->CreateTextFormat(<br /> L"微软雅黑",<br /> NULL,<br /> DWRITE_FONT_WEIGHT_DEMI_BOLD,<br /> DWRITE_FONT_STYLE_NORMAL,<br /> DWRITE_FONT_STRETCH_ULTRA_EXPANDED,<br /> 24,<br /> L"MyFont", //locale<br /> &p_pText<br /> );<br /> }</p> <p> if (SUCCEEDED(hr))<br /> {<br /> // Center the text horizontally and vertically.<br /> p_pText->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_CENTER);</p> <p> p_pText->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_CENTER);</p> <p> }<br /> // Obtain the size of the drawing area.<br /> GetClientRect(hWnd, &rc);</p> <p> // Create a Direct2D render target<br /> hr = pD2DFactory->CreateHwndRenderTarget(D2D1::RenderTargetProperties(),<br /> D2D1::HwndRenderTargetProperties(hWnd,D2D1::SizeU(rc.right - rc.left, rc.bottom - rc.top)),<br /> &p_pRenderTarget);</p> <p> //从资源中载入一张图片<br /> //LoadResourceBitmap(p_pRenderTarget, p_pImageFactory,MAKEINTRESOURCE(IDR_JPG1),L"jpg",&p_pBitmap);</p> <p> //从硬盘上载入一张图片<br /> LoadBitmapFromFile(p_pRenderTarget,p_pImageFactory,L"car.jpg",0,0,&p_pBitmap);</p> <p> // 设置笔刷<br /> if (SUCCEEDED(hr))<br /> {<br /> p_pRenderTarget->CreateSolidColorBrush(D2D1::ColorF(D2D1::ColorF::Black),&p_pBlackBrush);<br /> p_pRenderTarget->CreateBitmapBrush( p_pBitmap ,&p_pBitmapBrush );<br /> }</p> <p> return hr;<br /> }

其中IWICImagingFactory类提供了一个高效的图形绘制接口

hr = CoCreateInstance(<br /> CLSID_WICImagingFactory,<br /> NULL,<br /> CLSCTX_INPROC_SERVER,<br /> IID_PPV_ARGS(&p_pImageFactory)<br /> );

 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 Rander()<br /> {</p> <p> if(!p_pRenderTarget)<br /> return ;</p> <p> static const WCHAR szBitmapBrushText[] = L"图片笔刷";</p> <p> // Define the shape of rectangles to be filled with brushes.<br /> D2D1_RECT_F rcBrushRect = D2D1::RectF(0, 0, 470, 613);</p> <p> // Define the area where captions are drawn.<br /> D2D1_RECT_F rcTextRect = D2D1::RectF(0, 1065, 450, 200);</p> <p> p_pRenderTarget->BeginDraw();<br /> p_pRenderTarget->SetTransform(D2D1::Matrix3x2F::Identity());</p> <p> p_pRenderTarget->Clear(D2D1::ColorF(D2D1::ColorF::White));</p> <p> // Translate for the bitmap brush.<br /> p_pRenderTarget->SetTransform(D2D1::Matrix3x2F::Translation(D2D1::SizeF(150, 50)));</p> <p> // Draw a caption.</p> <p> //Demonstrate a bitmap brush.<br /> p_pRenderTarget->FillRectangle(&rcBrushRect, p_pBitmapBrush);<br /> p_pRenderTarget->DrawRectangle(&rcBrushRect, p_pBlackBrush, 1, NULL);<br /> p_pRenderTarget->DrawText(<br /> szBitmapBrushText,<br /> ARRAYSIZE(szBitmapBrushText) - 1,<br /> p_pText,<br /> &rcTextRect,<br /> p_pBlackBrush<br /> );<br /> p_pRenderTarget->EndDraw();</p> <p>}