Polylines

Polylines are linear (order 2) curves and are parameterized as such. That is, a polyline with three points is parameterized from 0 to 2, where the line between the first point and the second point is 0 to 1, and the line between the second point and the third point is 1 to 2. See the heading "Curves, loops, and knot vectors" on page 79 for information on linear curves and curve order.

	TPolyline	AddBefore	GetPoints	RemovePoint
		Append	GetNumberOfPoints	ReverseDirection
		DragPosition	IsRectilinear	SetPoint
		GetPoint	NearestParametric	SetPoints

The following code creates and draws the star polyline shown in the margin. With a polyline, the first point and the last point do not close.

  TGPolyline aPolylineGeometry;
  aPolylineGeometry.Append( TGPoint( 70, 40 ) );
  aPolylineGeometry.Append( TGPoint( 50, 80 ) );
  aPolylineGeometry.Append( TGPoint( 10, 90 ) );
  aPolylineGeometry.Append( TGPoint( 45, 110 ) );
  aPolylineGeometry.Append( TGPoint( 25, 155 ) );
  aPolylineGeometry.Append( TGPoint( 70, 130 ) );
  aPolylineGeometry.Append( TGPoint( 115, 155 ) );
  aPolylineGeometry.Append( TGPoint( 95, 110 ) );
  aPolylineGeometry.Append( TGPoint( 130, 90 ) );
  aPolylineGeometry.Append( TGPoint( 90, 80 ) );
  
  TGrafBundle* aBundle = new TGrafBundle( TFrameBundle( TRGBColor( 0, 0, 0), 5.0 ) );
  TPolyline aPolyline( aPolylineGeometry, aBundle );
  aPolyline.Draw( thePort );