select case CdiGetProgMode()
  case CDI_2D_MODE
    i_ret%=CdiMenuEntry(IDM_DRAW_LINE_LINE_SET, term%, menu_hit%)

  case CDI_3D_MODE
    i_ret%=CdiMenuEntry(IDM_DRAW3_LINE, term%, menu_hit%)

end select

sub GetMidPoint()

  dim object1 as CDI_OSL_OBJECT
  dim line_buffer as CDI_LINESET_BUFFER
  dim vertex_id1 as integer
  dim vertex_id2 as integer
  dim null_ptr as long
  dim pnt0 as CDI_DDD_POINT
  dim pnt1 as CDI_DDD_POINT
  dim pnt2 as CDI_DDD_POINT
  dim center as CDI_DDD_POINT
  dim snapmode as integer
  dim l_osl as long
  dim op as integer

  l_osl&=CdiCreateLocalOsl(CDI_OBJECT_COLOR, 0&, CDI_REDRAW_OSL)
  snapmode%=CdiGetSnapMode()
  i_ret=CdiSetSnapMode(CDI_NOSNAP)
  i_ret=CdiSelectbyPoint(l_osl&,"Select line segment for center point",CDI_OBJECT_SELECTION,CDI_FALSE,CDI_TRUE,pnt0(0),CDI_SEL2D_LINESETS)
  if i_ret=CDI_ABORT or i_ret=CDI_ERROR then
    i_ret=CdiSetSnapMode(snapmode%)
    i_ret=CdiFreeLocalOsl(l_osl&)
    exit sub
  end if

  i_ret=CdiOslItem(l_osl, 0, object1)
  i_ret=CdiSelectLineSegment(object1.sid, pnt0, vertex_id1, vertex_id2)
  i_ret=CdiObjInfo(object1.sid, line_buffer)
  i_ret=CdiObjInfoxy(pnt1, op, vertex_id1-1, line_buffer)
  i_ret=CdiObjInfoxy(pnt2, op, vertex_id2-1, line_buffer)
  call CdiLineCenter(pnt1, pnt2, center)
  call CdiCoordInput(center, CDI_ABS_UNITS)
  i_ret=CdiSetSnapMode(snapmode)
  i_ret=CdiFreeLocalOsl(l_osl)

end sub

sub LineLength()

  Dim line_buffer As CDI_LINESET_BUFFER
  Dim pnt1 as CDI_DDD_POINT
  Dim object1 as CDI_OSL_OBJECT

  i_ret%=CdiSelectbyPoint(0&, "Select line to find total length", CDI_OBJECT_SELECTION, CDI_FALSE, CDI_TRUE, pnt0, CDI_SEL2D_ALL)
  i_ret%=CdiOslItem(0&, 0, object1.sid)
  i_ret%=CdiObjInfo(object1.sid, line_buffer)
  length&=0
  i_ret%=CdiObjInfoxy(pnt1, op%, 0, line_buffer)

  for vertex%=1 to line_buffer.number_of_elements
    i_ret%=CdiObjInfoxy(pnt2, op%, vertex%, line_buffer)
    distance&=0
    call CdiWorldDist(pnt1, pnt2, distance&)
    pnt1=pnt2
    length&=length&+distance&
  next vertex%

  'convert from database units to current units
  dim dist as string * 30
  call CdiDbutoString(length&, dist)
  msg$="length = "+dist
  msgbox msg$,0

end sub

sub GetArea()

  Dim line_buffer As CDI_LINESET_BUFFER
  Dim pnt1 as CDI_DDD_POINT
  Dim object1 as CDI_OSL_OBJECT

  i_ret%=CdiSelectbyPoint(0&, "Select line to find area", CDI_OBJECT_SELECTION, CDI_FALSE, CDI_TRUE, pnt0, CDI_SEL2D_ALL)
  i_ret%=CdiOslItem(0&, 0, object1.sid)
  i_ret%=CdiObjInfo(object1.sid, line_buffer)

  ReDim xp(lvertex) As Long
  ReDim yp(lvertex) As Long
  For vertex%=0 To line_buffer.number_of_elements
    i_ret%=CdiObjInfoxy(pnt1, op%, vertex%, line_buffer)
    xp(vertex%)=pnt1.x
    yp(vertex%)=pnt1.y
  Next vertex%
  area#=0#
  Call CdiArea(xp(0), yp(0), line_buffer.number_of_elements, area#)

  'convert from database units to current units
  'factor for square feet
  carea=144
  msg$="area = "+area#/carea/CdiPntsPerUnit^2
  msgbox msg$,0

end sub

sub AddVertex()

  Dim line_buffer As CDI_LINESET_BUFFER
  Dim pnt0 as CDI_DDD_POINT
  Dim pnt1 as CDI_DDD_POINT
  Dim object1 as CDI_OSL_OBJECT

  i_ret%=CdiSelectbyPoint(0&, "Select line to add vertex", CDI_OBJECT_SELECTION, CDI_FALSE, CDI_TRUE, pnt0, CDI_SEL2D_ALL)
  i_ret%=CdiOslItem(0&, 0, object1.sid)
  i_ret%=CdiObjInfo(object1.sid, line_buffer)
  i_ret%=CdiGetPoint("Select new vertex point",pnt1)
  i_ret%=CdiVertexAdd(object1.sid ,line_buffer.number_of_elements, pnt1, op%, CDI_ABS_UNITS, CDI_OBJECT_COLOR, new_segid&)

end sub