Direct2D (15) : 剪辑

绘制在 RenderTarget.PushAxisAlignedClip() 与 RenderTarget.PopAxisAlignedClip() 之间的内容将被指定的矩形剪辑。

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uses Direct2D, D2D1;



procedure TForm1.FormPaint(Sender: TObject);

var

  cvs: TDirect2DCanvas;

  R,RClip: TRect;

begin

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



  R := ClientRect;

  InflateRect(R, -ClientWidth div 6, -ClientHeight div 6);



  {设置剪辑区域}

  RClip := R;

  InflateRect(RClip, -ClientWidth div 6, 0);



  cvs.BeginDraw;

  cvs.Pen.Color := clGreen;

  cvs.Brush.Color := clGreen;



  cvs.Ellipse(R); //第一个椭圆



  cvs.RenderTarget.PushAxisAlignedClip(RClip, D2D1_ANTIALIAS_MODE_PER_PRIMITIVE); //参数2是抗锯齿的模式

  cvs.Brush.Color := clWhite;

  cvs.Ellipse(R); //第二个椭圆

  cvs.RenderTarget.PopAxisAlignedClip;



  cvs.EndDraw;

  cvs.Free;

end;



procedure TForm1.FormResize(Sender: TObject);

begin

  Repaint;

end;

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效果图：

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