Removing incisions from curve paths.

Joe
over 1 year ago

Hello, code ninjas. I was wondering if someone here may have a better approach what I am doing (that sometimes produces errors as well).

Task is getting rid of incisions of an object outline. Basically making the lines smooth from a certain size.

This is my current approach - applying an outside contour, breaking it apart and then applying same size inside contour and thus getting a clean path. But it seems a little inefficient and sometimes produces errors (when small details are too close to one another). May there be some other, more efficient way to do this?

Thanks in advance!

Edit: The sample is a rectangle just for clarity, in reality we are dealing with all sorts of random shapes, so it cannot just be replaced.

Edit 2: Looks like I am using the same method that Shelby came up with here: https://forum.oberonplace.com/showpost.php?p=6874&postcount=3 so chances of there being something better do not seem that great. But, perhaps, something has changed over time. Aiming at 2018 at the moment, but this may justify a later version if it offers something new.

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  • +1 over 1 year ago

    How about examining the curve and identifying the cusp nodes that are the "sharp points" of those incisions? Perhaps by using the angles of the control points of the two segments that involve that node?

    Here's something you could look at:

    Sub test_it()

Dim s As Shape
Dim noderangeThis As New NodeRange

    Set s = ActiveShape
    examine_curve_and_identify_sharp_point_nodes s.Curve, 5, noderangeThis
    noderangeThis.Delete
    
    Refresh
    
End Sub

Function examine_curve_and_identify_sharp_point_nodes(ByVal SourceCurve As Curve, ByVal CPAngleTolerance As Double, ByRef SharpPointNodeRange As NodeRange) As Boolean

Dim nodeThis As Node
Dim lngNodeIndex_subpath_getting As Long
Dim subPathThis As SubPath

    On Error GoTo ErrHandler

    For Each subPathThis In SourceCurve.SubPaths
        If subPathThis.Closed Then
            For lngNodeIndex_subpath_getting = 1 To subPathThis.Nodes.Count
                Set nodeThis = subPathThis.Nodes(lngNodeIndex_subpath_getting)
                If nodeThis.Type = cdrCuspNode Then
                    If nodeThis.Segment.Type = cdrLineSegment And nodeThis.NextSegment.Type = cdrLineSegment Then
                        If AnglesAreClose(nodeThis.Segment.EndingControlPointAngle, nodeThis.NextSegment.StartingControlPointAngle, CPAngleTolerance) Then
                            SharpPointNodeRange.Add nodeThis
                        End If
                    End If
                End If
            Next lngNodeIndex_subpath_getting
        End If
    Next subPathThis
    
ExitFunc:
    Exit Function
    
ErrHandler:
    MsgBox "Error occurred: " & Err.Description & vbCrLf & vbCrLf & "examine_curve_and_identify_sharp_point_nodes()", vbExclamation
    Resume ExitFunc
End Function

Public Function AnglesAreClose(ByRef Angle_A As Double, ByRef Angle_B As Double, ByRef Tolerance As Double) As Boolean

    If Abs(Angle_A - Angle_B) < Tolerance Then
        AnglesAreClose = True
    Else
        If (Angle_A >= 0 And Angle_A <= Tolerance) And (Angle_B <= 360 And Angle_B >= 360 - Tolerance) Then
            If Angle_A + (360 - Angle_B) < Tolerance Then
                AnglesAreClose = True
            End If
        Else
            If (Angle_A <= 360 And Angle_A >= 360 - Tolerance) And (Angle_B >= 0 And Angle_B <= Tolerance) Then
                If (360 - Angle_A) + Angle_B < Tolerance Then
                    AnglesAreClose = True
                End If
            End If
        End If
    End If
End Function

    One demonstration: