Direct2D (4) : DrawGeometry() 与 FillGeometry()
原始的 Direct2D 只提供了几种简单图形(直线、矩形、圆角矩形、椭圆)的绘制与填充,更多集合图形或路径的描绘要使用 DrawGeometry() 和 FillGeometry()。
既然能绘制更复杂的图形,当然也能绘制基本图形,先试下使用 DrawGeometry()、FillGeometry() 实现矩形、圆角矩形和椭圆。
方法的参数是 ID2D1Geometry 接口,ID2D1RectangleGeometry、ID2D1RoundedRectangleGeometry、ID2D1EllipseGeometry 都是它的子接口。
ID2D1Factory 提供了实现这三个接口的方法,从 D2DFactory() 可获取 ID2D1Factory 接口。
测试代码:
uses Direct2D, D2D1; procedure TForm1.FormPaint(Sender: TObject); var cvs: TDirect2DCanvas; fPt: TD2DPoint2f; fLeft,fTop: Single; iEllipse: ID2D1EllipseGeometry; iRectangle: ID2D1RectangleGeometry; iRoundedRectangle: ID2D1RoundedRectangleGeometry; iFactory: ID2D1Factory; begin fPt := D2D1PointF(ClientWidth / 2, ClientHeight / 2); fLeft := ClientWidth / 4; fTop := ClientHeight / 4; iFactory := D2DFactory(); iFactory.CreateRectangleGeometry(D2D1RectF(fLeft, fTop, fLeft*3, fTop*3), iRectangle); iFactory.CreateRoundedRectangleGeometry(D2D1RoundedRect(D2D1RectF(fLeft, fTop, fLeft*3, fTop*3), 32, 32), iRoundedRectangle); iFactory.CreateEllipseGeometry(D2D1Ellipse(fPt, fLeft, fTop), iEllipse); cvs := TDirect2DCanvas.Create(Canvas, ClientRect); cvs.BeginDraw; cvs.Pen.Color := clRed; cvs.Brush.Color := clBlack; cvs.FillGeometry(iRectangle); cvs.Brush.Color := clGreen; cvs.FillGeometry(iRoundedRectangle); cvs.Brush.Color := clBlue; cvs.FillGeometry(iEllipse); cvs.DrawGeometry(iRectangle); cvs.DrawGeometry(iRoundedRectangle); cvs.DrawGeometry(iEllipse); cvs.EndDraw; cvs.Free; end; procedure TForm1.FormResize(Sender: TObject); begin Repaint; end;
posted on 2011-03-31 17:42 万一 阅读(2918) 评论(0) 编辑 收藏