VB.Net Tutorial/2D Graphics/Curve

Draw Closed Curve

Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
public class DrawClosedCurve
   public Shared Sub Main
        Application.Run(New FillModesForm)
   End Sub
End class

Public Class FillModesForm
    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.ruponentModel.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.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        components = New System.ruponentModel.Container()
        Me.Text = "FillModesForm"
    End Sub
#End Region
    Private Sub FillModesForm_Paint(ByVal sender As Object, ByVal e As PaintEventArgs) Handles MyBase.Paint
        Dim g As Graphics = e.Graphics
        Dim x As Integer = 0
        Dim y As Integer = 0
        Dim width As Integer = Me.ClientRectangle.Width / 2
        Dim height As Integer = Me.ClientRectangle.Height
        Dim fillBrush As Brush = Brushes.Gray
        Dim pen As Pen = New Pen(Color.Red, 4)
        Dim pointPen As Pen = New Pen(Color.Black, 3)
        pointPen.StartCap = pointPen.EndCap = LineCap.SquareAnchor
        Dim points As PointF() = New PointF() {New PointF(x + 25, y + height - 25), New PointF(x + width - 25, y + height - 25), New PointF(x + 25, height / 2), New PointF(x + width - 25, y + 25), New PointF(x + 25, y + 25), New PointF(x + width - 25, height / 2)}
        g.DrawClosedCurve(pen, points)

    End Sub
End Class

Draw curve

Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
public class DrawCurve
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class
public class Form1
  Inherits System.Windows.Forms.Form
  Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
        Dim a As Graphics =  e.Graphics
        Dim mypen As Pen
        Dim mypoints(21) As PointF
        Dim i As Integer
        mypen = New Pen(System.Drawing.Color.Red, 3)
        For i = 0 To 9
            mypoints(i).X = 10 * i
            mypoints(i).Y = i * i * 3
        Next
        For i = 10 To 20
            mypoints(i).X = 10 * i
            mypoints(i).Y = (200 + i * i) / 15
        Next
        a = Me.CreateGraphics
        a.Clear(Me.BackColor)
        a.DrawCurve(mypen, mypoints)
        a.Dispose()
        mypen.Dispose()
  End Sub
  Public Sub New()
    MyBase.New()
    Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
    Me.ClientSize = New System.Drawing.Size(292, 273)
    Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
  End Sub
End Class

Draw curve with Tension setting

Imports System.Collections
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
public class DrawCurveTension
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class
Public Class Form1
    Private BendPoints As New Generic.List(Of Point)
    Private Sub Form1_MouseClick(ByVal sender As Object,ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseClick
        BendPoints.Add(New Point(e.X, e.Y))
        Me.Refresh()
    End Sub
    Private Sub Form1_Paint(ByVal sender As Object, _
          ByVal e As System.Windows.Forms.PaintEventArgs) _
          Handles Me.Paint
        Dim tension As Single
        Dim canvas As Graphics
        Dim scanPoint As Point
        Const PointSize As Integer = 2
        tension = TensionLevel.Value / TensionLevel.Maximum
        LabelTension.Text = "Tension:  " & tension.ToString
        canvas = e.Graphics
        For Each scanPoint In BendPoints
            canvas.FillEllipse(Brushes.Red,scanPoint.X - PointSize,scanPoint.Y - PointSize,PointSize * 2, PointSize * 2)
        Next scanPoint
        If (BendPoints.Count > 1) Then
            canvas.DrawCurve(Pens.Black, BendPoints.ToArray, tension)
        End If
    End Sub
    Private Sub TensionLevel_ValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) _
          Handles TensionLevel.ValueChanged
        Me.Refresh()
    End Sub
    Private Sub ActReset_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles ActReset.Click
        BendPoints.Clear()
        Me.Refresh()
    End Sub
End Class

<Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _
Partial Class Form1
    Inherits System.Windows.Forms.Form
    "Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing AndAlso components IsNot Nothing Then
            components.Dispose()
        End If
        MyBase.Dispose(disposing)
    End Sub
    "Required by the Windows Form Designer
    Private components As System.ruponentModel.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.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.LabelTension = New System.Windows.Forms.Label
        Me.TensionLevel = New System.Windows.Forms.TrackBar
        Me.ActReset = New System.Windows.Forms.Button
        CType(Me.TensionLevel, System.ruponentModel.ISupportInitialize).BeginInit()
        Me.SuspendLayout()
        "
        "LabelTension
        "
        Me.LabelTension.AutoSize = True
        Me.LabelTension.Location = New System.Drawing.Point(24, 32)
        Me.LabelTension.Name = "LabelTension"
        Me.LabelTension.Size = New System.Drawing.Size(66, 13)
        Me.LabelTension.TabIndex = 0
        Me.LabelTension.Text = "Tension: 0.0"
        "
        "TensionLevel
        "
        Me.TensionLevel.Location = New System.Drawing.Point(136, 24)
        Me.TensionLevel.Name = "TensionLevel"
        Me.TensionLevel.Size = New System.Drawing.Size(224, 45)
        Me.TensionLevel.TabIndex = 1
        "
        "ActReset
        "
        Me.ActReset.Location = New System.Drawing.Point(392, 24)
        Me.ActReset.Name = "ActReset"
        Me.ActReset.Size = New System.Drawing.Size(75, 23)
        Me.ActReset.TabIndex = 2
        Me.ActReset.Text = "Reset"
        Me.ActReset.UseVisualStyleBackColor = True
        "
        "Form1
        "
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(547, 264)
        Me.Controls.Add(Me.ActReset)
        Me.Controls.Add(Me.TensionLevel)
        Me.Controls.Add(Me.LabelTension)
        Me.Name = "Form1"
        Me.Text = "Drawing Cardinal Splines"
        CType(Me.TensionLevel, System.ruponentModel.ISupportInitialize).EndInit()
        Me.ResumeLayout(False)
        Me.PerformLayout()
    End Sub
    Friend WithEvents LabelTension As System.Windows.Forms.Label
    Friend WithEvents TensionLevel As System.Windows.Forms.TrackBar
    Friend WithEvents ActReset As System.Windows.Forms.Button
End Class

Draw Sin curve

Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports System.Math
public class DrawCurveSin
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class
public class Form1
  Inherits System.Windows.Forms.Form
  Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
        Dim a As Graphics =  e.Graphics
        Dim mypen As Pen
        Dim mypoints() As PointF
        Dim i As Integer
        Dim mycount As Integer
        mypen = New Pen(System.Drawing.Color.Red, 3)
        mycount = Me.Width / 10
        ReDim mypoints(mycount)
        For i = 1 To mycount
            mypoints(i).X = i * 10
            mypoints(i).Y = -1 * (Sin(i)) ^ 2 * Me.Height
        Next
        a = Me.CreateGraphics
        a.Clear(Me.BackColor)
        a.ScaleTransform(1, -1)
        a.DrawCurve(mypen, mypoints)
        a.Dispose()
        mypen.Dispose()
  End Sub
  Public Sub New()
    MyBase.New()
    Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
    Me.ClientSize = New System.Drawing.Size(292, 273)
    Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
  End Sub
End Class

Fill Closed Curve

Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
public class FillClosedCurve
   public Shared Sub Main
        Application.Run(New FillModesForm)
   End Sub
End class

Public Class FillModesForm
    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.ruponentModel.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.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        components = New System.ruponentModel.Container()
        Me.Text = "FillModesForm"
    End Sub
#End Region
    Private Sub FillModesForm_Paint(ByVal sender As Object, ByVal e As PaintEventArgs) Handles MyBase.Paint
        Dim g As Graphics = e.Graphics
        Dim x As Integer = 0
        Dim y As Integer = 0
        Dim width As Integer = Me.ClientRectangle.Width / 2
        Dim height As Integer = Me.ClientRectangle.Height
        Dim fillBrush As Brush = Brushes.Gray
        Dim pen As Pen = New Pen(Color.Red, 4)
        Dim pointPen As Pen = New Pen(Color.Black, 3)
        pointPen.StartCap = pointPen.EndCap = LineCap.SquareAnchor
        Dim points As PointF() = New PointF() {New PointF(x + 25, y + height - 25), New PointF(x + width - 25, y + height - 25), New PointF(x + 25, height / 2), New PointF(x + width - 25, y + 25), New PointF(x + 25, y + 25), New PointF(x + width - 25, height / 2)}
        g.DrawClosedCurve(pen, points)
        Dim fill As FillMode = FillMode.Winding
        g.FillClosedCurve(fillBrush, points, fill)
    End Sub
End Class