Using Programming Languages other than VBA

Sub Example_ControlPoints()
   ' This example creates a Spline object in model space, reads the control points
   ' of the Spline and then modifies the control points of the Spline.

	Dim splineObj As AcadSpline
	Dim startTan(0 To 2) As Double, endTan(0 To 2) As Double
	Dim fitPoints(0 To 8) As Double
	Dim UserMessage As String
	Dim ControlPoints As Variant
	Dim iCount As Long, iPoint As Integer

	' Define the Spline object
	startTan(0) = 0.5: startTan(1) = 0.5: startTan(2) = 0
	endTan(0) = 0.5: endTan(1) = 0.5: endTan(2) = 0
	fitPoints(0) = 0: fitPoints(1) = 0: fitPoints(2) = 0
	fitPoints(3) = 5:   fitPoints(4) = 5: fitPoints(5) = 0
	fitPoints(6) = 10: fitPoints(7) = 0: fitPoints(8) = 0

	' Create new Spline object
	Set splineObj = ThisDrawing.ModelSpace.AddSpline(fitPoints, startTan, endTan)
	ThisDrawing.Application.ZoomAll

	' Display control points for this Spline
	GoSub DISPLAYPOINTS

	' Modify control points for this Spline
	ControlPoints(0) = 3
	splineObj.ControlPoints = ControlPoints
	ThisDrawing.Application.ZoomAll
	
	' Display new control points for this Spline
	GoSub DISPLAYPOINTS
	
	Exit Sub

DISPLAYPOINTS:
	ControlPoints = splineObj.ControlPoints

	' Display in groups of three
	UserMessage = ""
	iPoint = 0
	For iCount = 0 To UBound(ControlPoints) Step 3
		iPoint = iPoint + 1
		UserMessage = UserMessage & iPoint & ")" & vbTab
		UserMessage = UserMessage & ControlPoints(iCount)
		UserMessage = UserMessage & ", " & ControlPoints(iCount + 1)
		UserMessage = UserMessage & ", " & ControlPoints(iCount + 2)
		UserMessage = UserMessage & vbCrLf
	Next

	MsgBox "The " & splineObj.NumberOfControlPoints & " Spline control points are: " & vbCrLf & vbCrLf & UserMessage

	Return
End Sub