Sounds to me like a job for beziers...
You'll find a little VB application after my signature.
--
Bob Powell [MVP]
Visual C#, System.Drawing
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Imports System.Drawing.Drawing2D
Public Class Form1
Inherits System.Windows.Forms.Form
#Region " Windows Form Designer generated code "
Public Sub New()
MyBase.New()
'This call is required by the Windows Form Designer.
InitializeComponent()
'Add any initialization after the InitializeComponent() call
End Sub
'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub
'Required by the Windows Form Designer
Private components As System.ComponentModel.IContainer
'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
Friend WithEvents NumericUpDown1 As System.Windows.Forms.NumericUpDown
Friend WithEvents Label1 As System.Windows.Forms.Label
Friend WithEvents Label2 As System.Windows.Forms.Label
Friend WithEvents NumericUpDown2 As System.Windows.Forms.NumericUpDown
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.NumericUpDown1 = New System.Windows.Forms.NumericUpDown
Me.Label1 = New System.Windows.Forms.Label
Me.Label2 = New System.Windows.Forms.Label
Me.NumericUpDown2 = New System.Windows.Forms.NumericUpDown
CType(Me.NumericUpDown1,
System.ComponentModel.ISupportInitialize).BeginIni t()
CType(Me.NumericUpDown2,
System.ComponentModel.ISupportInitialize).BeginIni t()
Me.SuspendLayout()
'
'NumericUpDown1
'
Me.NumericUpDown1.Location = New System.Drawing.Point(72, 16)
Me.NumericUpDown1.Maximum = New Decimal(New Integer() {10, 0, 0, 0})
Me.NumericUpDown1.Minimum = New Decimal(New Integer() {1, 0, 0, 0})
Me.NumericUpDown1.Name = "NumericUpDown1"
Me.NumericUpDown1.Size = New System.Drawing.Size(72, 20)
Me.NumericUpDown1.TabIndex = 0
Me.NumericUpDown1.Value = New Decimal(New Integer() {3, 0, 0, 0})
'
'Label1
'
Me.Label1.Location = New System.Drawing.Point(8, 16)
Me.Label1.Name = "Label1"
Me.Label1.Size = New System.Drawing.Size(40, 23)
Me.Label1.TabIndex = 1
Me.Label1.Text = "Lines"
'
'Label2
'
Me.Label2.Location = New System.Drawing.Point(8, 48)
Me.Label2.Name = "Label2"
Me.Label2.Size = New System.Drawing.Size(56, 23)
Me.Label2.TabIndex = 2
Me.Label2.Text = "Degrees"
'
'NumericUpDown2
'
Me.NumericUpDown2.Location = New System.Drawing.Point(72, 48)
Me.NumericUpDown2.Maximum = New Decimal(New Integer() {90, 0, 0, 0})
Me.NumericUpDown2.Minimum = New Decimal(New Integer() {1, 0, 0, 0})
Me.NumericUpDown2.Name = "NumericUpDown2"
Me.NumericUpDown2.Size = New System.Drawing.Size(72, 20)
Me.NumericUpDown2.TabIndex = 0
Me.NumericUpDown2.Value = New Decimal(New Integer() {1, 0, 0, 0})
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(448, 382)
Me.Controls.Add(Me.Label2)
Me.Controls.Add(Me.Label1)
Me.Controls.Add(Me.NumericUpDown1)
Me.Controls.Add(Me.NumericUpDown2)
Me.Name = "Form1"
Me.Text = "Form1"
CType(Me.NumericUpDown1, System.ComponentModel.ISupportInitialize).EndInit( )
CType(Me.NumericUpDown2, System.ComponentModel.ISupportInitialize).EndInit( )
Me.ResumeLayout(False)
End Sub
#End Region
Protected Overrides Sub OnMouseMove(ByVal e As
System.Windows.Forms.MouseEventArgs)
mouse = New Point(e.X, e.Y)
Invalidate()
End Sub
Dim mouse As Point
Protected Overrides Sub OnPaint(ByVal e As
System.Windows.Forms.PaintEventArgs)
Dim n As Integer
Dim absoluteangle As Single = 0
For n = 0 To Me.NumericUpDown1.Value - 1
Dim rotationangle As Single
If (n Mod 2 = 0) Then
rotationangle = absoluteangle
Else
rotationangle = -absoluteangle
End If
Dim firstPoint As PointF = New PointF(Me.ClientRectangle.Width / 2, 20)
Dim lastpoint As PointF = New PointF(mouse.X, mouse.Y)
Dim vector As PointF = New PointF(lastpoint.X - firstPoint.X, lastpoint.Y -
firstPoint.Y)
'get the hypotenuse...
Dim hypot As Single = CSng(Math.Sqrt((vector.X * vector.X) + (vector.Y *
vector.Y)))
'create a point at the center of the hypotenuse...
Dim center As New PointF(firstPoint.X + (vector.X / 2), firstPoint.Y +
(vector.Y / 2))
'Create bezier control points
Dim cp1 As PointF() = New PointF() {center}
Dim cp2 As PointF() = New PointF() {center}
'rotate one point around the first position...
Dim mx As New Matrix
mx.RotateAt(rotationangle, firstPoint)
mx.TransformPoints(cp1)
'rotate the other point around the last position...
mx = New Matrix
mx.RotateAt(-rotationangle, lastpoint)
mx.TransformPoints(cp2)
'draw a bezier
e.Graphics.DrawBezier(Pens.Black, firstPoint, cp1(0), cp2(0), lastpoint)
absoluteangle += Me.NumericUpDown2.Value
Next
End Sub
End Class
"Carl Gilbert" <cn*@newsgroup.nospam> wrote in message
news:uz*************@TK2MSFTNGP10.phx.gbl...
Hi
I have a math kinda problem where I'm trying to split some lines when two
or more lines connect two shapes. The reason I am doing this is to make
it clear that there are multiple lines connecting the two shapes.
http://www.blackwaterbadgers.co.uk/image1.bmp
Image 1 shows how if you have a line between two shapes, the line is
straight. if you have more than one line, the lines will start
overlapping each other and essentially look like just the one line. What
I have done is to add a pivot to the centre of the line so the lines can
be given a curve as shown in Image 1.
The middle pivot is created when the line is straight so I know its
location. I also know the locations of either end of the line so from
this I can get the angle of the line. I also know the distance by which I
want to offset the middle pivot.
My plan is to run some code (most of this I have written) that looks to
see how many lines are going between the two shapes. If it is one line
then I will leave it alone. If it is more than one line, I want to
separate out the lines.
http://www.blackwaterbadgers.co.uk/image2.bmp
Based on Image 2
I know the location of the two red dots which give me oppA and adjA, from
this I can get the angle x. As I want the middle pivot to move at a right
angle to its origin, I know the angle of y.
hypB is the distance I want to move the pivot from its origin so from this
I can get oppB and adjB.
Based on the middle pivot, I can now use these measurements to offset the
middle pivot.
The only problem is, because I have used Math.Abs to ensure that I now
working with negative numbers, I now need to establish the direction in
which I want to offset the pivot. This isn't too much of a problem but I
am having trouble working out the distance by which to offset the pivot
based on the number of lines.
So my question is, how can I determine the offset direct and length based
on the number of lines?
Ideally, I would like to split the lines evenly so that if I had an odd
number of lines then the middle line would stay straight with the
remaining lines either side. If I have an even number of lines then the
lines would be split evenly.
A colleague suggested going through each line and offsetting each pivot in
the same direction and then moving all the pivots back to a more central
position but I'm sure it would be better to just work out the direction to
move each pivot and by how much.
Does anyone have any idea on how I could achieve this?
Regards, Carl Gilbert
