Direct2D (26) : 获取几何图形的边界-白红宇

Direct2D (26) : 获取几何图形的边界

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发布时间：2019-06-14

本文共 1096 字，大约阅读时间需要 3 分钟。

{相关方法}ID2D1Geometry.GetBounds();        //获取边界矩形ID2D1Geometry.GetWidenedBounds(); //获取包含画笔区域的边界矩形

测试代码：

uses Direct2D, D2D1;procedure TForm1.FormPaint(Sender: TObject);var  cvs: TDirect2DCanvas;  iGeometry: ID2D1EllipseGeometry;  R1,R2: TD2DRectF;  iBrush: ID2D1SolidColorBrush;begin  {几何图形}  D2DFactory.CreateEllipseGeometry(D2D1Ellipse(D2D1PointF(ClientWidth/2, ClientHeight/2), ClientWidth/4, ClientHeight/4), iGeometry);  {分别获取两种类型的边界}  iGeometry.GetBounds(TD2DMatrix3x2F.Identity, R1);  iGeometry.GetWidenedBounds(25, nil, TD2DMatrix3x2F.Identity, 0, R2);  cvs := TDirect2DCanvas.Create(Canvas, ClientRect);  cvs.BeginDraw;  cvs.RenderTarget.Clear(D2D1ColorF(clWhite));  {绘制原图形}  cvs.RenderTarget.CreateSolidColorBrush(D2D1ColorF(clRed, 0.75), nil, iBrush);  cvs.RenderTarget.FillGeometry(iGeometry, iBrush);  {绘制边界}  iBrush.SetOpacity(1);  cvs.RenderTarget.DrawRectangle(R1, iBrush);  cvs.RenderTarget.DrawRectangle(R2, iBrush);  cvs.EndDraw;  cvs.Free;end;procedure TForm1.FormResize(Sender: TObject);begin  Repaint;end;

效果图：