ControlPoints Property (ActiveX)

Specifies the control points of a spline.

Supported platforms: Windows only

Signature

VBA:

object.ControlPoints

object

Type: Spline

The object this property applies to.

Property Value

Read-only: No

Type: Variant (array of doubles)

An array of 3D WCS control points for the spline.

Remarks

You can find out how many control points a spline has by using the NumberOfControlPoints property.

Examples

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

Visual LISP:

(vl-load-com)
(defun c: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.
    (setq acadObj (vlax-get-acad-object))
    (setq doc (vla-get-ActiveDocument acadObj))
    
    ;; Define the Spline object
    (setq startTan (vlax-3d-point 0.5 0.5 0)
          endTan (vlax-3d-point 0.5 0.5 0)
          fitPoints (vlax-make-safearray vlax-vbDouble '(0 . 8)))
    (vlax-safearray-fill fitPoints '(0 0 0
				     5 5 0
				     10 0 0
				    )
    )
    
    ;; Create new Spline object
    (setq modelSpace (vla-get-ModelSpace doc))
    (setq splineObj (vla-AddSpline modelSpace fitPoints startTan endTan))
    (vla-ZoomAll acadObj)
    
    ;; Display control points for this Spline
    (setq ControlPoints (vlax-variant-value (vla-get-ControlPoints splineObj)))
    
    ;; Display in groups of three
    (setq UserMessage ""
          iPoint 0
	  iCount 0)
  
    (while (>= (vlax-safearray-get-u-bound ControlPoints 1) iCount)
        (setq iPoint (1+ iPoint))
        (setq UserMessage (strcat UserMessage (itoa iPoint) ")  "
                                  (rtos (nth iCount (vlax-safearray->list ControlPoints)) 2) ", "
                                  (rtos (nth (+ iCount 1) (vlax-safearray->list ControlPoints)) 2) ", "
                                  (rtos (nth (+ iCount 2) (vlax-safearray->list ControlPoints)) 2) "\n"
		          )
	)

        (setq iCount (+ iCount 3))
    )
    
    (alert (strcat "The " (itoa (vla-get-NumberOfControlPoints splineObj)) " Spline control points are: " "\n\n" UserMessage))
  
    ;; Modify control points for this Spline
    (setq newFitPoint (vlax-3d-point 8 2 0))
  
    (vla-AddFitPoint splineObj 3 newFitPoint)
    (setq ControlPoints (vlax-variant-value (vla-get-ControlPoints splineObj)))
    (vla-ZoomAll acadObj)
        
    ;; Display new control points for this Spline
    (setq UserMessage ""
          iPoint 0
	  iCount 0)
  
    (while (>= (vlax-safearray-get-u-bound ControlPoints 1) iCount)
        (setq iPoint (1+ iPoint))
        (setq UserMessage (strcat UserMessage (itoa iPoint) ")  "
                                  (rtos (nth iCount (vlax-safearray->list ControlPoints)) 2) ", "
                                  (rtos (nth (+ iCount 1) (vlax-safearray->list ControlPoints)) 2) ", "
                                  (rtos (nth (+ iCount 2) (vlax-safearray->list ControlPoints)) 2) "\n"
		          )
	)

        (setq iCount (+ iCount 3))
    )

    (alert (strcat "The " (itoa (vla-get-NumberOfControlPoints splineObj)) " Spline control points are: " "\n\n" UserMessage))
)