Direct2D (19) : 圖層之 TD2D1LayerParameters.geometricMask (使用幾何圖形剪裁圖層)

uses Direct2D, D2D1;procedure TForm1.FormPaint(Sender: TObject);var  cvs: TDirect2DCanvas;  iLayer: ID2D1Layer;  rLayerParameters: TD2D1LayerParameters;  wic: TWICImage;  R: TRect;  iEllipse: ID2D1EllipseGeometry;begin  wic := TWICImage.Create;  wic.LoadFromFile('C:\Temp\Test.png');  R := Rect(0, 0, wic.Width, wic.Height);  {幾何圖形}  D2DFactory.CreateEllipseGeometry(D2D1Ellipse(D2D1PointF(wic.Width/2, wic.Height/2), wic.Width/2, wic.Height/2), iEllipse);  cvs := TDirect2DCanvas.Create(Canvas, ClientRect);  cvs.RenderTarget.SetTransform(TD2DMatrix3x2F.Translation((ClientWidth-wic.width)/2, (ClientHeight-wic.height)/2));  cvs.BeginDraw;  cvs.RenderTarget.CreateLayer(nil, iLayer);  rLayerParameters.contentBounds := R;  rLayerParameters.geometricMask := iEllipse; //!  rLayerParameters.maskAntialiasMode := D2D1_ANTIALIAS_MODE_PER_PRIMITIVE;  rLayerParameters.maskTransform := TD2DMatrix3x2F.Identity;  rLayerParameters.opacity := 1.0;//  rLayerParameters.opacityBrush := nil;  rLayerParameters.layerOptions := D2D1_LAYER_OPTIONS_NONE;  cvs.RenderTarget.PushLayer(rLayerParameters, iLayer);  cvs.StretchDraw(R, wic);  cvs.RenderTarget.PopLayer;  cvs.EndDraw;  cvs.Free;  wic.Free;end;procedure TForm1.FormResize(Sender: TObject);begin  Repaint;end;

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