Using Programming Languages other than VBA

Sub Example_StartTangent()
	' This example creates a spline. It then queries the current setting for
	' the StartTangent, and then changes the StartTangent to a new value.

	' Create the spline
	Dim splineObj As AcadSpline
	Dim startTan(0 To 2) As Double
	Dim endTan(0 To 2) As Double
	Dim fitPoints(0 To 8) As Double
	Dim msg As String

	startTan(0) = 0.5: startTan(1) = 0.5: startTan(2) = 0
	endTan(0) = 0.5: endTan(1) = 0.5: endTan(2) = 0
	fitPoints(0) = 1: fitPoints(1) = 1: fitPoints(2) = 0
	fitPoints(3) = 5: fitPoints(4) = 5: fitPoints(5) = 0
	fitPoints(6) = 10: fitPoints(7) = 0: fitPoints(8) = 0
	Set splineObj = ThisDrawing.ModelSpace.AddSpline(fitPoints, startTan, endTan)

	ThisDrawing.Regen True
	GoSub GETPOINTS
	MsgBox "The StartTangent for the spline is  " & msg, vbInformation, "StartTangent Example"

	Dim newTan(0 To 2) As Double
	newTan(0) = 1.5: newTan(1) = 0.707: newTan(2) = 2

	' Change the start tangent of Spline to (1.5, 0.707, 2)
	splineObj.EndTangent = newTan

	ThisDrawing.Regen True
	GoSub GETPOINTS
	MsgBox "The StartTangent has been changed to " & msg, vbInformation, "StartTangent Example"

	Exit Sub

GETPOINTS:
	Dim count As Integer
	msg = ""
	' Get the coordinates from the start tangent
	For count = 0 To 2
		msg = msg & Format(splineObj.StartTangent(count), "0.###") & ", "
	Next
	msg = VBA.Left(msg, Len(msg) - 2)
	Return
End Sub