ArcObjects Library Reference (Geometry)  

IConstructCircularArc.ConstructTangentAndPoint Method

Constructs an arc with one endpoint being p, tangent to s, and connected to s. If atFrom is true, the connection is at s's from point, otherwise at s's to point.

[Visual Basic .NET]
Public Sub ConstructTangentAndPoint ( _
    ByVal s As ISegment, _
    ByVal atFrom As Boolean, _
    ByVal p As IPoint _
)
[C#]
public void ConstructTangentAndPoint (
    ISegment s,
    bool atFrom,
    IPoint p
);
[C++]
HRESULT ConstructTangentAndPoint(
  ISegment* s,
  VARIANT_BOOL atFrom,
  IPoint* p
);
[C++]

Parameters

s 

  s is a parameter of type ISegment

atFrom 
  atFrom is a parameter of type VARIANT_BOOL
p 

  p is a parameter of type IPoint

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Description

Constructs a CircularArc given the Tangent Segment, the desired segment endpoint (the From Point), and the desired To Point.  The Center Point of the constructed CircularArc lies on the Normal to the desired segment endpoint on the same side of the extended tangent as the To Point.  If the To Point lies on the tangent line from the desired segment endpoint, an IsLine CircularArc is constructed.

Remarks

 

ConstructCircularArc Tangent Segment Example

[C#]

        private void ConstructTangentAndPoint()
        {
            IConstructCircularArc constructCircularArc = new CircularArcClass();
            ICircularArc circularArc = constructCircularArc as ICircularArc;

            IPoint fromPoint1 = new PointClass();
            fromPoint1.PutCoords(100, 100);
            IPoint toPoint1 = new PointClass();
            toPoint1.PutCoords(50, 50);
            ILine line1 = new LineClass();
            line1.PutCoords(fromPoint1, toPoint1);

            IPoint point = new PointClass();
            point.PutCoords(100, 75);
            constructCircularArc.ConstructTangentAndPoint(line1 as ISegment, false, point);

            String report = "Length : " + circularArc.Length + "\n" +
                            "Radius : " + circularArc.Radius + "\n" +
                            "Chord Height : " + circularArc.ChordHeight + "\n" +
                            "Central Angle (Rad) : " + circularArc.CentralAngle + "\n" +
                            "From Angle (Rad) : " + circularArc.FromAngle + "\n" +
                            "To Angle (Rad) : " + circularArc.ToAngle + "\n" +
                            "Center Point : " + circularArc.CenterPoint.X + " , " + circularArc.CenterPoint.Y + "\n" +
                            "From Point : " + circularArc.FromPoint.X + " , " + circularArc.FromPoint.Y + "\n" +
                            "To Point : " + circularArc.ToPoint.X + " , " + circularArc.ToPoint.Y;
            System.Windows.Forms.MessageBox.Show(report);
        }
       

[Visual Basic .NET]

    Private Sub ConstructTangentAndPoint()
        Dim pConstructCircularArc As ESRI.ArcGIS.Geometry.IConstructCircularArc
        Dim pCArc As ESRI.ArcGIS.Geometry.ICircularArc
        Dim pToPoint As ESRI.ArcGIS.Geometry.IPoint
        Dim pFromPoint As ESRI.ArcGIS.Geometry.IPoint
        Dim pPoint As ESRI.ArcGIS.Geometry.IPoint
        Dim pLine1 As ESRI.ArcGIS.Geometry.ILine
        pConstructCircularArc = New ESRI.ArcGIS.Geometry.CircularArc
        pCArc = pConstructCircularArc
        pFromPoint = New ESRI.ArcGIS.Geometry.Point
        pToPoint = New ESRI.ArcGIS.Geometry.Point
        pLine1 = New ESRI.ArcGIS.Geometry.Line
        pFromPoint.PutCoords(100, 100)
        pToPoint.PutCoords(100, 400)
        pLine1.PutCoords(pFromPoint, pToPoint)
        pPoint = New ESRI.ArcGIS.Geometry.Point
        pPoint.PutCoords(200, 400)
        pConstructCircularArc.ConstructTangentAndPoint(pLine1, False, pPoint)
        Debug.Print("Length : " & pCArc.Length)
        Debug.Print("Radius : " & pCArc.Radius)
        Debug.Print("Chord Height : " & pCArc.ChordHeight)
        Debug.Print("Central Angle (Rad) : " & pCArc.CentralAngle)
        Debug.Print("From Angle (Rad) : " & pCArc.FromAngle)
        Debug.Print("To Angle (Rad) : " & pCArc.ToAngle)
        Debug.Print("Center Point : " & pCArc.CenterPoint.X & " , " & pCArc.CenterPoint.Y)
        Debug.Print("From Point : " & pCArc.FromPoint.X & " , " & pCArc.FromPoint.Y)
        Debug.Print("To Point : " & pCArc.ToPoint.X & " , " & pCArc.ToPoint.Y)
    End Sub

See Also

IConstructCircularArc Interface | IConstructCircularArc.ConstructTangentRadiusAngle Method | IConstructCircularArc.ConstructTangentRadiusArc Method | IConstructCircularArc.ConstructTangentChordTangent Method | IConstructCircularArc.ConstructTangentRadiusChord Method | IConstructCircularArc.ConstructTangentChordArc Method | IConstructCircularArc.ConstructTangentRadiusTangent Method | IConstructCircularArc.ConstructTangentArcTangent Method | IConstructCircularArc.ConstructTangentAngleChord Method | IConstructCircularArc.ConstructTangentAngleTangent Method | IConstructCircularArc.ConstructTangentAndPoint Method | IConstructCircularArc.ConstructTangentAngleArc Method