IntersectWith Method (ActiveX)

Gets the points where one object intersects another object in the drawing.

Supported platforms: Windows only

Signature

VBA:

RetVal = object.IntersectWith(IntersectObject, ExtendOption)

object

Type: All drawing objects (except PViewport and PolygonMesh), AttributeReference

The objects this method applies to.

IntersectObject

Access: Input-only

Type: Object

The object can be one of the supported drawing objects or an AttributeReference.

ExtendOption

Access: Input-only

Type: AcExtendOption enum

This option specifies if none, one or both, of the objects are to be extended in order to attempt an intersection.

• acExtendNone: Does not extend either object.
• acExtendThisEntity: Extends the base object.
• acExtendOtherEntity: Extends the object passed as an argument.
• acExtendBoth: Extends both objects.

Return Value (RetVal)

Type: Variant (array of doubles)

The array of points where one object intersects another object in the drawing.

Remarks

If the two objects do not intersect, no data is returned. You can request the point of intersection that would occur if one or both of the objects were extended to meet the other. For example, in the following illustration, Line1 is the base object from which this method was called and line3 is the object passed as a parameter. If the ExtendOption passed is acExtendThisEntity, point A is returned as the point where line1 would intersect line3 if line1 were extended. If the ExtendOption is acExtendOtherEntity, no data is returned because even if line3 were extended, it would not intersect line1.

If the intersection type is acExtendBothEntities and line2 is passed as the parameter entity, point B is returned. If the ExtendOption is acExtendNone and line2 is the parameter entity, no data is returned.

Examples

VBA:

Sub Example_IntersectWith()
    ' This example creates a line and circle and finds the points at
    ' which they intersect.
    
    ' Create the line
    Dim lineObj As AcadLine
    Dim startPt(0 To 2) As Double
    Dim endPt(0 To 2) As Double
    startPt(0) = 1: startPt(1) = 1: startPt(2) = 0
    endPt(0) = 5: endPt(1) = 5: endPt(2) = 0
    Set lineObj = ThisDrawing.ModelSpace.AddLine(startPt, endPt)
        
    ' Create the circle
    Dim circleObj As AcadCircle
    Dim centerPt(0 To 2) As Double
    Dim radius As Double
    centerPt(0) = 3: centerPt(1) = 3: centerPt(2) = 0
    radius = 1
    Set circleObj = ThisDrawing.ModelSpace.AddCircle(centerPt, radius)
    ZoomAll
      
    ' Find the intersection points between the line and the circle
    Dim intPoints As Variant
    intPoints = lineObj.IntersectWith(circleObj, acExtendNone)
    
    ' Print all the intersection points
    Dim I As Integer, j As Integer, k As Integer
    Dim str As String
    If VarType(intPoints) <> vbEmpty Then
        For I = LBound(intPoints) To UBound(intPoints)
            str = "Intersection Point[" & k & "] is: " & intPoints(j) & "," & intPoints(j + 1) & "," & intPoints(j + 2)
            MsgBox str, , "IntersectWith Example"
            str = ""
            I = I + 2
            j = j + 3
            k = k + 1
        Next
    End If
End Sub

Visual LISP:

(vl-load-com)
(defun c:Example_IntersectWith()
    ;; This example creates a line and circle and finds the points at
    ;; which they intersect.
    (setq acadObj (vlax-get-acad-object))
    (setq doc (vla-get-ActiveDocument acadObj))

    ;; Create the line
    (setq startPt (vlax-3d-point 1 1 0)
          endPt (vlax-3d-point 5 5 0))  

    (setq modelSpace (vla-get-ModelSpace doc))  
    (setq lineObj (vla-AddLine modelSpace startPt endPt))
        
    ;; Create the circle
    (setq centerPt (vlax-3d-point 1 1 0)
          radius 1)
    (setq circleObj (vla-AddCircle modelSpace centerPt radius))
    (vla-ZoomAll acadObj)
      
    ;; Find the intersection points between the line and the circle
    (setq intPoints (vla-IntersectWith lineObj circleObj acExtendNone))
    
    ;; Print all the intersection points
    (setq I 0
          j 0
          k 0)
    (if (/= (type intPoints) vlax-vbEmpty)
        (while (>= (vlax-safearray-get-u-bound (vlax-variant-value intPoints) 1) I)
            (setq tempPoint (vlax-safearray->list (vlax-variant-value intPoints)))
            (setq str (strcat "Intersection Point[" (itoa k) "] is: " (rtos (nth j tempPoint) 2) ","
                                                                      (rtos (nth (1+ j) tempPoint) 2) ","
                                                                      (rtos (nth (+ j 2) tempPoint) 2)))
            (alert str)
            (setq str ""
                  I (+ I 2)
                  j (+ j 3)
                  k (1+ k))
        )
    )
)