API Documentation > CorelDRAW > 2025-v26 > SubPath > IVGSubPath
SubPath.GetCurveSpeedAt method
Gets the Curve's Speed at the current subpath
Syntax:
Function GetCurveSpeedAt(Optional ByVal Offset As Double = 0.5, Optional ByVal OffsetType As cdrSegmentOffsetType = cdrRelativeSegmentOffset) As Double
Parameters:
Name Type Description
Offset
Double
Specifies the offset, in document units, of the point. 5.
OffsetType
Specifies the offset type of the point, and returns cdrSegmentOffsetType.
Remarks:
The GetCurveSpeedAt method returns a value indicating the rate at which the curvature of a subpath changes at a given point. A value close to 0 means that the curvature is steady - for example, in a circle. A value greater than 0 means that the curvature increases - for example, in a spiral. A value of less than 0 value means that the curvature decreases - for example, in an unwinding spiral.
Examples:
The following VBA example shows how the curvature changes in the middle of the first subpath of the selected curve.
Sub Test()
Dim c As Double
Dim sp As SubPath
Set sp = ActiveShape.Curve.Subpaths(1)
c = sp.GetCurveSpeedAt(0.5, cdrRelativeSegmentOffset)
If Abs(c) < 0.01 Then
  MsgBox "Curvature is steady: " & c
Else
  If c > 0 Then

 MsgBox "Curvature is increasing: " & c
  Else

 MsgBox "Curvature is decreasing: " & c
  End If
End If 
End Sub