In the String Art Add-In v1.0 we put together a class called cRegularPolygon which exposes a DrawSectionByBothCornerPoints() method to allow an end-user to draw a polygon section. This method works very well but it’s a bit cumbersome for the end-user to have to calculate the centre and end points of the axes so, for the next installment of the add-in, we’re going to add a new method which will allow them to provide a more convenient set of information to draw the section. Ideally we would have a single method name such as DrawSection() into which the end users could pass different parameter sets but, since VBA doesn’t support overloading, we have to create separate methods with different names. Here’s the full code for this version of the add-in, some release notes and examples.
Edit 11th December: I just noticed that when I submitted the post, WordPress parsed a number of characters in the code so that it would not compile. For example, " had been parsed as ". I’ve fixed it now and while I was doing it I took the opportunity to refactor part of the code so that it’s slightly cleaner to use.
String Art Add-In v1.1 Downloadable Version
This version of the add-in can be downloaded from here. To use the add-in, follow the instructions I gave for the v1.0 release.
String Art Add-In v1.1 Code
Module: mInterface
Option Explicit
'these functions allow outside projects to create instances of
'this project's classes
Public Function CreateRegularPolygon() As cRegularPolygon
Set CreateRegularPolygon = New cRegularPolygon
End Function
Public Function CreatePoint() As cPoint
Set CreatePoint = New cPoint
End Function
Module: mMath
Option Explicit
Public Function Pi() As Double
Pi = 3.14159265358979
End Function
Public Function RadiansInCircle() As Double
RadiansInCircle = 2 * Pi
End Function
Public Function RadiansInSemiCircle() As Double
RadiansInSemiCircle = Pi
End Function
Public Function RadiansInRightAngle() As Double
RadiansInRightAngle = Pi / 2
End Function
Public Function ConvertDegreesToRadians(ByVal dblDegrees As Double) As Double
ConvertDegreesToRadians = dblDegrees / 180 * Pi
End Function
Class Module: cRegularPolygon
-
Instancing: PublicNotCreatable
Option Explicit
'this describes how the points should be joined together
Public Enum RegularPolygonAxisJoinStyle
Cobweb = 0
Matrix = 1
Parabolic = 2
End Enum
'this method lets the user draw a polygon section by providing
'the coordinates of the two corner points
Public Sub DrawSectionByBothCornerPoints( _
ByRef wstTarget As Worksheet, _
ByRef clsCentrePoint As cPoint, _
ByRef clsCornerPoint1 As cPoint, _
ByRef clsCornerPoint2 As cPoint, _
ByVal lngPointsPerAxis As Long, _
ByVal lngAxisJoinStyle As RegularPolygonAxisJoinStyle, _
Optional ByRef varLineColor As Variant)
'quick feasibility check
If PointsInSamePosition(clsCentrePoint, clsCornerPoint1) Or _
PointsInSamePosition(clsCentrePoint, clsCornerPoint2) Or _
PointsInSamePosition(clsCornerPoint1, clsCornerPoint2) Then
Err.Raise 666, "Centre and corner points cannot be in the same position"
End If
'draw the section
DrawAndJoinAxesByStyle wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
clsCornerPoint1:=clsCornerPoint1, _
clsCornerPoint2:=clsCornerPoint2, _
lngPointsPerAxis:=lngPointsPerAxis, _
lngAxisJoinStyle:=lngAxisJoinStyle, _
varLineColor:=varLineColor
End Sub
'this method lets the user draw a polygon section by providing
'theta, the angle between the two axes
'rho, the angle of the first axis (clockwise) from vertical
'and the length of the axes
Public Sub DrawSectionByAxisLength( _
ByRef wstTarget As Worksheet, _
ByRef clsCentrePoint As cPoint, _
ByVal dblTheta As Double, _
ByVal sngAxisLength As Single, _
ByVal lngPointsPerAxis As Long, _
ByVal lngAxisJoinStyle As RegularPolygonAxisJoinStyle, _
Optional ByVal dblRho As Double = 0, _
Optional ByRef varLineColor As Variant)
Dim clsCornerPoint1 As cPoint, clsCornerPoint2 As cPoint
'quick feasibility check
If sngAxisLength <= 0 Then Err.Raise 666, "Axis length must be greater than 0"
'determine end point of axis1
Set clsCornerPoint1 = GetCornerPointFromAngleAndLength( _
clsCentrePoint:=clsCentrePoint, _
dblAngle:=dblRho, _
sngLength:=sngAxisLength)
'determine the end point of axis2
Set clsCornerPoint2 = GetCornerPointFromAngleAndLength( _
clsCentrePoint:=clsCentrePoint, _
dblAngle:=dblRho + dblTheta, _
sngLength:=sngAxisLength)
'draw the section
DrawAndJoinAxesByStyle wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
clsCornerPoint1:=clsCornerPoint1, _
clsCornerPoint2:=clsCornerPoint2, _
lngPointsPerAxis:=lngPointsPerAxis, _
lngAxisJoinStyle:=lngAxisJoinStyle, _
varLineColor:=varLineColor
End Sub
'this method draws the axes
'and delegates the axis join duty
'depending on the join style
Private Sub DrawAndJoinAxesByStyle( _
ByRef wstTarget As Worksheet, _
ByRef clsCentrePoint As cPoint, _
ByRef clsCornerPoint1 As cPoint, _
ByRef clsCornerPoint2 As cPoint, _
ByVal lngPointsPerAxis As Long, _
ByVal lngAxisJoinStyle As RegularPolygonAxisJoinStyle, _
Optional ByRef varLineColor As Variant)
Dim clsAxis1 As cPoints, clsAxis2 As cPoints
'calculate the join points along each axis
Set clsAxis1 = GetLineOfPoints( _
clsStartPoint:=clsCentrePoint, _
clsEndPoint:=clsCornerPoint1, _
lngPointsCount:=lngPointsPerAxis)
Set clsAxis2 = GetLineOfPoints( _
clsStartPoint:=clsCentrePoint, _
clsEndPoint:=clsCornerPoint2, _
lngPointsCount:=lngPointsPerAxis)
'draw the axes
JoinPointToPoint _
wstTarget:=wstTarget, _
clsPoint1:=clsCentrePoint, _
clsPoint2:=clsCornerPoint1, _
varForeColor:=varLineColor
JoinPointToPoint _
wstTarget:=wstTarget, _
clsPoint1:=clsCentrePoint, _
clsPoint2:=clsCornerPoint2, _
varForeColor:=varLineColor
'join the axes
If lngAxisJoinStyle = RegularPolygonAxisJoinStyle.Matrix Then
AxisMatrixJoin _
wstTarget:=wstTarget, _
clsAxis1:=clsAxis1, _
clsAxis2:=clsAxis2, _
varLineColor:=varLineColor
ElseIf lngAxisJoinStyle = RegularPolygonAxisJoinStyle.Parabolic Then
AxisParabolicJoin _
wstTarget:=wstTarget, _
clsAxis1:=clsAxis1, _
clsAxis2:=clsAxis2, _
varLineColor:=varLineColor
ElseIf lngAxisJoinStyle = RegularPolygonAxisJoinStyle.Cobweb Then
AxisCobWebJoin _
wstTarget:=wstTarget, _
clsAxis1:=clsAxis1, _
clsAxis2:=clsAxis2, _
varLineColor:=varLineColor
Else
Err.Raise 666, "Invalid join type"
End If
End Sub
'matrix join will join all points on an axis to all points on another axis
Private Sub AxisMatrixJoin( _
ByRef wstTarget As Worksheet, _
ByRef clsAxis1 As cPoints, _
ByRef clsAxis2 As cPoints, _
Optional ByRef varLineColor As Variant)
Dim clsPoint1 As cPoint, clsPoint2 As cPoint
For Each clsPoint1 In clsAxis1
For Each clsPoint2 In clsAxis2
JoinPointToPoint _
wstTarget:=wstTarget, _
clsPoint1:=clsPoint1, _
clsPoint2:=clsPoint2, _
varForeColor:=varLineColor
Next clsPoint2
Next clsPoint1
End Sub
'parabolic join will join points on an axis by reverse position, starting from the 2nd point
Private Sub AxisParabolicJoin( _
ByRef wstTarget As Worksheet, _
ByRef clsAxis1 As cPoints, _
ByRef clsAxis2 As cPoints, _
Optional ByRef varLineColor As Variant)
Const lngSTART_POINT As Long = 2
Dim p1 As Long
If clsAxis1.Count <> clsAxis2.Count Then
Err.Raise 666, "Can only parabolic join if points counts are equal"
Else
For p1 = lngSTART_POINT To clsAxis1.Count
JoinPointToPoint _
wstTarget:=wstTarget, _
clsPoint1:=clsAxis1(p1), _
clsPoint2:=clsAxis2(clsAxis2.Count - p1 + lngSTART_POINT), _
varForeColor:=varLineColor
Next p1
End If
End Sub
'cobweb join will join points on two axes which have the same position
Private Sub AxisCobWebJoin( _
ByRef wstTarget As Worksheet, _
ByRef clsAxis1 As cPoints, _
ByRef clsAxis2 As cPoints, _
Optional ByRef varLineColor As Variant)
Dim p1 As Long
If clsAxis1.Count <> clsAxis2.Count Then
Err.Raise 666, "Can only cobweb join if points counts are equal"
Else
For p1 = 1 To clsAxis1.Count
JoinPointToPoint _
wstTarget:=wstTarget, _
clsPoint1:=clsAxis1(p1), _
clsPoint2:=clsAxis2(p1), _
varForeColor:=varLineColor
Next p1
End If
End Sub
'this method calculates the positions of
'evenly dispersed points along a line -
'start and end points are included in the point count
Private Function GetLineOfPoints( _
ByRef clsStartPoint As cPoint, _
ByRef clsEndPoint As cPoint, _
ByVal lngPointsCount As Long) As cPoints
Dim sngXDelta As Single, sngYDelta As Single
Dim p As Long
Dim clsPoint As cPoint
'get change in X and Y per point
sngXDelta = (clsEndPoint.X - clsStartPoint.X) / (lngPointsCount - 1)
sngYDelta = (clsEndPoint.Y - clsStartPoint.Y) / (lngPointsCount - 1)
Set GetLineOfPoints = New cPoints
'get the coordinates of the points along the line
For p = 0 To lngPointsCount - 1
Set clsPoint = New cPoint
clsPoint.X = clsStartPoint.X + p * sngXDelta
clsPoint.Y = clsStartPoint.Y + p * sngYDelta
GetLineOfPoints.Add clsPoint
Next p
End Function
'this method draws a line between two points
Private Sub JoinPointToPoint( _
ByRef wstTarget As Worksheet, _
ByRef clsPoint1 As cPoint, _
ByRef clsPoint2 As cPoint, _
Optional ByRef varForeColor As Variant)
Dim shp As Shape
Set shp = wstTarget.Shapes.AddLine _
(BeginX:=clsPoint1.X, _
BeginY:=clsPoint1.Y, _
EndX:=clsPoint2.X, _
EndY:=clsPoint2.Y)
If Not IsMissing(varForeColor) Then
shp.Line.ForeColor.RGB = varForeColor
End If
End Sub
'calculates the corner point coordinates given
'the position of the centrepoint, the angle of the axis
'and the length of the axis
Private Function GetCornerPointFromAngleAndLength( _
ByRef clsCentrePoint As cPoint, _
ByVal dblAngle As Double, _
ByVal sngLength As Single) As cPoint
Set GetCornerPointFromAngleAndLength = New cPoint
GetCornerPointFromAngleAndLength.X = clsCentrePoint.X + sngLength * Sin(dblAngle)
GetCornerPointFromAngleAndLength.Y = clsCentrePoint.Y - sngLength * Cos(dblAngle)
End Function
'determines if two points are in the same position
Private Function PointsInSamePosition( _
ByRef clsPoint1 As cPoint, _
ByRef clsPoint2 As cPoint) As Boolean
If clsPoint1.X = clsPoint2.X Then
PointsInSamePosition = (clsPoint1.Y = clsPoint2.Y)
End If
End Function
Class Module: cPoint
-
Instancing: PublicNotCreatable
Option Explicit
Private psngX As Single
Private psngY As Single
Public Property Let X(ByVal sngValue As Single)
psngX = sngValue
End Property
Public Property Get X() As Single
X = psngX
End Property
Public Property Let Y(ByVal sngValue As Single)
psngY = sngValue
End Property
Public Property Get Y() As Single
Y = psngY
End Property
Class Module: cPoints
-
Instancing: Private
-
See instructions here on how to set the procedure level attributes
Option Explicit
Private pcolPoints As Collection
Public Sub Add(ByRef Point As cPoint)
pcolPoints.Add Point
End Sub
Public Function Count() As Long
Count = pcolPoints.Count
End Function
'be able to loop through the collection with For Each
Public Function NewEnum() As IUnknown
'Attribute NewEnum.VB_UserMemID = -4 has been set in text editor
Set NewEnum = pcolPoints.[_NewEnum]
End Function
'default member of the class
Public Function Item(ByVal lngIndex As Long) As cPoint
'Attribute Value.VB_UserMemId = 0 has been set in text editor
Set Item = pcolPoints(lngIndex)
End Function
Private Sub Class_Initialize()
Set pcolPoints = New Collection
End Sub
Release Notes
DrawSectionByAxisLength
The new DrawSectionByAxisLength() method allows users to draw the section by defining the coordinates of the centre point, the length (r) of the axes, the angle (Theta) between the axes and the angle (Rho) of the first axis clockwise from 12 o’clock. Theta and Rho must be specified in radians, not degrees.
Trigonometry is then used within the class to calculate the axis end point coordinates. The general formulae to calculate the x and y coordinates of the end points are:
EndX = CentreX + r * Sin(Angle)
EndY = CentreY - r * Cos(Angle)
The reason the change in Y is subtracted is because Y coordinates increase from top to bottom on an Excel worksheet.
mMath
The VBA trigonometry functions work with radians rather than degrees. It’s been at least fifteen years since I last did any trigonometry and picturing angles in radians just doesn’t come naturally to me. I know there are 90 degrees in a right-angle, but it’s not instinctive for me to say that there are Pi/2 radians in a right-angle. I’m probably not the only person out there who thinks this way, so I figured that it would be useful to have some methods to help ‘degree orientated’ end-users work in radians.
Examples
I decided to have a go at moving a parabolic polygon section around an Excel sheet and, with a few carefully placed DoEvents commands, the output isn’t too shabby. I never had moving shapes in mind when I built the add-in so the implementation is a little clunky, but nonetheless works. If string art animation proves to be popular then I’ll implement it properly in a future release.
Here’s a section bouncing between two walls:
And here’s a section with a rotating axis:
And, finally, four rotating axes with a bit of colour:
Here’s the code for them:
Option Explicit
Sub Animation1()
Const lngPOINTS_PER_AXIS As Long = 15
Const sngAXIS_LENGTH As Single = 60
Dim clsRegPol As StringArt.cRegularPolygon
Dim clsCentrePoint As StringArt.cPoint
Dim sngStartX As Single, sngStartY As Single
Dim sngLeftWallX As Single, sngRightWallX As Single
Dim dblTheta As Double, dblRho As Double
Dim X As Double
Dim wstTarget As Worksheet
Set wstTarget = Worksheets("Sheet1")
With wstTarget
'clear previous run
.DrawingObjects.Delete
'boundaries
With .Range("A1")
sngLeftWallX = .Left + .Width
End With
sngRightWallX = .Range("F1").Left
'start point coordinates
With .Range("D5")
sngStartX = .Left
sngStartY = .Top
End With
End With
'start in the middle
Set clsCentrePoint = StringArt.CreatePoint
clsCentrePoint.X = sngStartX
clsCentrePoint.Y = sngStartY
'draw our section and group the lines so we can move them together
Set clsRegPol = StringArt.CreateRegularPolygon
dblRho = StringArt.RadiansInRightAngle / 2
dblTheta = StringArt.RadiansInRightAngle
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho
wstTarget.DrawingObjects.Group
'move the shape to the left wall
For X = clsCentrePoint.X * 10 To sngLeftWallX * 10 Step -1
DoEvents
wstTarget.Shapes(1).Left = X / 10
DoEvents
Next X
'collapse the shape
clsCentrePoint.X = sngLeftWallX
For dblTheta = StringArt.RadiansInRightAngle To _
StringArt.RadiansInSemiCircle Step StringArt.Pi / 400
DoEvents
wstTarget.DrawingObjects.Delete
dblRho = (StringArt.Pi - dblTheta) / 2
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho
DoEvents
Next dblTheta
'restore the shape facing the other way
For dblTheta = StringArt.RadiansInSemiCircle To _
StringArt.RadiansInRightAngle Step - StringArt.Pi / 400
DoEvents
wstTarget.DrawingObjects.Delete
clsCentrePoint.X = sngLeftWallX + Sin(StringArt.Pi / 2 - dblTheta / 2) * sngAXIS_LENGTH
dblRho = (3 / 2 * StringArt.Pi) - dblTheta / 2
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho
DoEvents
Next dblTheta
'move the shape to the right wall
wstTarget.DrawingObjects.Group
For X = clsCentrePoint.X * 10 To sngRightWallX * 10
DoEvents
wstTarget.Shapes(1).Left = X / 10 - wstTarget.Shapes(1).Width
DoEvents
Next X
'collapse the shape
clsCentrePoint.X = sngRightWallX
For dblTheta = StringArt.Pi / 2 To StringArt.Pi Step StringArt.Pi / 400
DoEvents
wstTarget.DrawingObjects.Delete
dblRho = (3 / 2 * StringArt.Pi) - dblTheta / 2
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho
DoEvents
Next dblTheta
'restore the shape facing the other way
For dblTheta = StringArt.Pi To StringArt.Pi / 2 Step - StringArt.Pi / 400
DoEvents
wstTarget.DrawingObjects.Delete
clsCentrePoint.X = sngRightWallX - Sin(StringArt.Pi / 2 - dblTheta / 2) * sngAXIS_LENGTH
dblRho = (StringArt.Pi - dblTheta) / 2
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho
DoEvents
Next dblTheta
'move the shape to the start point
wstTarget.DrawingObjects.Group
For X = clsCentrePoint.X * 10 To sngStartX * 10 Step -1
DoEvents
wstTarget.Shapes(1).Left = X / 10
DoEvents
Next X
End Sub
Option Explicit
Sub Animation2()
Const sngAXIS_LENGTH As Single = 80
Const lngPOINTS_PER_AXIS As Long = 10
Const dblRho As Double = 0
Const lngMAX_ROTATIONS As Double = 5
Dim clsCentrePoint As StringArt.cPoint
Dim clsRegPol As StringArt.cRegularPolygon
Dim dblTheta As Double
Dim lngRotation As Long
Dim wstTarget As Worksheet
Set wstTarget = Worksheets("Sheet1")
'centre point coordinates
Set clsCentrePoint = StringArt.CreatePoint
With wstTarget
'clear previous run
.DrawingObjects.Delete
With .Range("C7")
clsCentrePoint.X = .Left
clsCentrePoint.Y = .Top
End With
End With
'draw our polygon and group the lines so we can move them together
Set clsRegPol = StringArt.CreateRegularPolygon
For lngRotation = 1 To lngMAX_ROTATIONS
For dblTheta = 0 To 2 * StringArt.Pi Step StringArt.Pi / 180
DoEvents
wstTarget.DrawingObjects.Delete
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho, _
varLineColor:=CVar(RGB(0, 0, 0))
DoEvents
Next dblTheta
Next lngRotation
End Sub
Option Explicit
Sub Animation3()
Const sngAXIS_LENGTH As Single = 80
Const lngPOINTS_PER_AXIS As Long = 10
Const dblRho As Double = 0
Const lngMAX_ROTATIONS As Double = 5
Dim dblTheta As Double
Dim clsCentrePoint As StringArt.cPoint
Dim clsRegPol As StringArt.cRegularPolygon
Dim lngRotation As Long
Dim varLineColor As Variant
Dim wstTarget As Worksheet
Set wstTarget = Worksheets("Sheet1")
'centre point coordinates
Set clsCentrePoint = StringArt.CreatePoint
With wstTarget
'clear previous run
.DrawingObjects.Delete
With .Range("C7")
clsCentrePoint.X = .Left
clsCentrePoint.Y = .Top
End With
End With
'draw our polygon and group the lines so we can move them together
Set clsRegPol = StringArt.CreateRegularPolygon
varLineColor = CVar(RGB(230, 253, 95))
For lngRotation = 1 To lngMAX_ROTATIONS
For dblTheta = 0 To 2 * StringArt.Pi Step StringArt.Pi / 180
DoEvents
wstTarget.DrawingObjects.Delete
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho, _
varLineColor:=varLineColor
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=-dblTheta, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho, _
varLineColor:=varLineColor
If dblTheta > StringArt.Pi Then
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta - StringArt.Pi, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho, _
varLineColor:=varLineColor
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=-dblTheta + StringArt.Pi, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho, _
varLineColor:=varLineColor
End If
If dblTheta < StringArt.Pi Then
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=dblTheta + StringArt.Pi, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho, _
varLineColor:=varLineColor
clsRegPol.DrawSectionByAxisLength _
wstTarget:=wstTarget, _
clsCentrePoint:=clsCentrePoint, _
dblTheta:=-dblTheta - StringArt.Pi, _
sngAxisLength:=sngAXIS_LENGTH, _
lngPointsPerAxis:=lngPOINTS_PER_AXIS, _
lngAxisJoinStyle:=Parabolic, _
dblRho:=dblRho, _
varLineColor:=varLineColor
End If
DoEvents
Next dblTheta
Next lngRotation
End Sub
