Direct2D (9) : 显示图像

uses Direct2D;



procedure TForm1.FormPaint(Sender: TObject);

var

  cvs: TDirect2DCanvas;

  wic: TWICImage;

  R: TRect;

begin

  wic := TWICImage.Create;

  wic.LoadFromFile('C:\Temp\Test.png');



  cvs := TDirect2DCanvas.Create(Canvas, ClientRect);

  cvs.BeginDraw;



  cvs.Draw(10, 10, wic);



  R := Bounds(wic.Width div 2 + 10, wic.Height div 2 + 10, wic.Width div 2, wic.Height div 2);

  cvs.StretchDraw(R, wic, 192);



  cvs.EndDraw;

  cvs.Free;

  wic.Free;

end;

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效果图：

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用较原始的办法重做上面的例子(通过 wic)：

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uses Direct2D, D2D1, Wincodec, ActiveX;



{从指定文件建立 ID2D1Bitmap 对象的函数}

function GetD2D1Bitmap(RenderTarget: ID2D1RenderTarget; imgPath: string): ID2D1Bitmap;

var

  iWicFactory: IWICImagingFactory;

  iWICDecoder: IWICBitmapDecoder;

  iWICFrameDecode: IWICBitmapFrameDecode;

  iFormatConverter: IWICFormatConverter;

begin

  {获取建立 WIC 的工厂}

  CoCreateInstance(CLSID_WICImagingFactory, nil, CLSCTX_INPROC_SERVER, IID_IWICImagingFactory, iWicFactory);

  {打开并获取解码后的对象}

  iWicFactory.CreateDecoderFromFilename(PWideChar(imgPath), GUID_NULL, GENERIC_READ, WICDecodeMetadataCacheOnLoad, iWICDecoder);

  {获取第一帧}

  iWicDecoder.GetFrame(0, iWICFrameDecode);

  {获取格式转换器}

  iWicFactory.CreateFormatConverter(iFormatConverter);

  {转换到与 D2D 兼容的格式}

  iFormatConverter.Initialize(iWICFrameDecode, GUID_WICPixelFormat32bppPBGRA, WICBitmapDitherTypeNone, nil, 0, WICBitmapPaletteTypeMedianCut);

  {获取 ID2D1Bitmap}

  RenderTarget.CreateBitmapFromWicBitmap(iFormatConverter, nil, Result);

end;



procedure TForm1.FormPaint(Sender: TObject);

var

  cvs: TDirect2DCanvas;

  iBitmap: ID2D1Bitmap;

  fRect: TD2DRectF;

  fSize: TD2DSizeF;

begin

  cvs := TDirect2DCanvas.Create(Canvas, ClientRect);

  iBitmap := GetD2D1Bitmap(cvs.RenderTarget, 'C:\Temp\Test.png');



  iBitmap.GetSize(fSize);

  fRect := D2D1RectF(0, 0, fSize.width, fSize.height);

  cvs.BeginDraw;

  cvs.RenderTarget.SetTransform(TD2DMatrix3x2F.Translation(10, 10));

  cvs.RenderTarget.DrawBitmap(iBitmap, @fRect);



  fRect := D2D1RectF(0, 0, fSize.width/2, fSize.height/2);

  cvs.RenderTarget.SetTransform(TD2DMatrix3x2F.Translation(fRect.right+10, fRect.bottom+10));

  cvs.RenderTarget.DrawBitmap(iBitmap, @fRect, 0.75);



  cvs.EndDraw;

  cvs.Free;

end;

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