Direct2D (22) : 复合几何对象之 ID2D1TransformedGeometry-白红宇

Direct2D (22) : 复合几何对象之 ID2D1TransformedGeometry

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发布时间：2019-06-28

本文共 1290 字，大约阅读时间需要 4 分钟。

复合几何对象包括 ID2D1GeometryGroup 和 ID2D1TransformedGeometry，它们都继承自 ID2D1Geometry。

ID2D1TransformedGeometry 只是包含了 2D 变换的 ID2D1Geometry。

uses Direct2D, D2D1;procedure TForm1.FormPaint(Sender: TObject);var  cvs: TDirect2DCanvas;  iTransformedGeometry: ID2D1TransformedGeometry;  iRectangleGeometry: ID2D1RectangleGeometry;  iGeometry: ID2D1Geometry;  R: TRect;begin  {建立一个矩形的 ID2D1Geometry}  R := Bounds((ClientWidth-100) div 2, (ClientHeight-100) div 2, 100, 100);  D2DFactory.CreateRectangleGeometry(R, iRectangleGeometry);  {建立 ID2D1TransformedGeometry}  D2DFactory.CreateTransformedGeometry(    iRectangleGeometry,    TD2DMatrix3x2F.Rotation(45, ClientWidth/2, ClientHeight/2),    iTransformedGeometry  );  cvs := TDirect2DCanvas.Create(Canvas, ClientRect);  cvs.BeginDraw;  {绘制原始矩形}  cvs.Pen.Color := clGreen;  cvs.Pen.Width := 11;  cvs.DrawGeometry(iRectangleGeometry);  {绘制 ID2D1TransformedGeometry}  cvs.Brush.Color := clGreen;  cvs.FillGeometry(iTransformedGeometry);  {绘制从 ID2D1TransformedGeometry 再次获取的 iGeometry}  cvs.Pen.Color := clWhite;  cvs.Pen.Width := 1;  iTransformedGeometry.GetSourceGeometry(iGeometry);  cvs.DrawGeometry(iGeometry);  cvs.EndDraw;  cvs.Free;end;procedure TForm1.FormResize(Sender: TObject);begin  Repaint;end;

效果图：