Animasi Starfield dengan GDI+ VB.net

GDI+ merupakan evolusi dari GDI, yang membuat pengelolaan grafi k  menjadi jauh lebih mudah. Tip kali ini adalah memanfaatkan GDI+ untuk  mem buat animasi starfield.  Langkah-langkah untuk membuatnya adalah:  

1. Buat New Project (Windows Application)  dengan sebuah form baru, dan sebuah picture  box ber nama pbstars. Property yang perlu diubah  adalah BackColor menjadi hitam, Dock menjad  Fill, WaitOnLoad menjadi True. 
   
   
   
   
   
2. Buat sebuah class baru bernama clsStars. Class ini:                                                                                                                                                                                    
   
   Public Class clsStars
   Dim s_direction As Single = 0
   Dim s_angle As Double
   Dim center As Point
   Dim speed As Double = 0.2
   Dim s_accel As Double = 1.1
   Dim s_cd As Integer
   Dim s_x As Integer
   Dim s_y As Integer
   Dim s_pen() As Pen
   Dim s_hold As Double
   Dim s_depth As Integer = 2
   Dim s_count As Integer = 10
   Dim rn As New Random
   Private Structure fShip
   Dim spoint() As Point
   Dim cv As Single
   End Structure
   Private Structure Star
   Dim x As Single
   Dim y As Integer
   Dim z As Integer
   Dim xv As Double
   Dim yv As Double
   End Structure
   Dim Stars() As Star
3. Beberapa subrutin yang dibutuhkan adalah untuk inisialisasi, dan mengatur  gerakan star yang muncul. Public Sub IntializeStar(ByVal depth As Integer, ByVal     
   count As Integer, ByVal x As Integer, ByVal y As Integer)    
   ReDim Stars(count)    
   ReDim s_pen(depth)    
   center = New Point(x / 2, y / 2)    
   s_count = count    
   s_depth = depth    
   s_x = x    
   s_y = y    
   s_cd = Int(255 / s_depth)    
   For x = 0 To s_count Step s_depth    
   For y = 1 To depth    
   Try        
       Stars(x + y).x = rn.Next(0, s_x)    
       Stars(x + y).y = rn.Next(0, s_y)    
       Stars(x + y).z = y    
       StarAngle(x + y)    
       If x = 0 Then s_pen(y) = New Pen(Color.     
   FromArgb(Int(s_cd * y), Int(s_cd * y), Int(s_cd * y)), 2)    
   Catch ex As Exception    
   End Try    
   Next    
   Next    
   End Sub    
   Private Sub SetShip(ByVal Value As Single)    
   s_angle += Value    
   If s_angle > 180 Then s_angle = -180    
   If s_angle < -180 Then s_angle = 180    
   If s_direction < 0 Then    
   s_direction += Value * 2     
    Else   
   s_direction += Value   
   End If   
   If s_direction > 360 Then s_direction = -360   
   End Sub   
   Private Sub StarAngle(ByVal Id As Integer)   
   Dim x As Integer = Stars(Id).x - (center.X)   
   Dim y As Integer = Stars(Id).y - (center.Y)   
   Dim a As Double = Math.Atan2(y, x)   
   Stars(Id).xv = 2 * Math.Cos(a)   
   Stars(Id).yv = 2 * Math.Sin(a)   
   End Sub   
   Public Sub DrawShip(ByVal b As System.Windows.Forms.    
   PaintEventArgs)   
   Dim x As Integer   
   b.Graphics.TranslateTransform(center.X, center.Y)   
   For x = 1 To s_depth   
   SetShip(0.01)   
   b.Graphics.RotateTransform(s_angle, MatrixOrder.    
   Prepend)   
   b.Graphics.DrawPie(s_pen(x), New RectangleF(0, 0,    
   150, 150), s_direction, s_direction)   
   b.Graphics.DrawPie(s_pen(x), New RectangleF(0, 0,    
   150, 150), s_direction, -s_direction)   
   Next   
   End Sub   
   Public Sub DrawStars(ByVal b As System.Windows.Forms.    
   PaintEventArgs)   
   Dim x As Integer   
   b.Graphics.Clear(Color.Black)   
   For x = 1 To UBound(Stars)   
   If Stars(x).y > s_y Or Stars(x).y < 0 Or Stars(x).x    
   > s_x Or Stars(x).x < 0 Then   
   Stars(x).x = rn.Next(0, s_x)   
   Stars(x).y = rn.Next(0, s_y)   
   StarAngle(x)   
   Else   
   Stars(x).x += Stars(x).xv   
   Stars(x).y += Stars(x).yv   
   Stars(x).xv *= s_accel + (0.001 * Stars(x).z)   
   Stars(x).yv *= s_accel + (0.001 * Stars(x).z)   
   End If   
   b.Graphics.DrawLine(s_pen(Stars(x).z),    
   CInt(Stars(x).x - Stars(x).xv), CInt(Stars(x).y - Stars(x).    
   yv), Stars(x).x, Stars(x).y)   
   Next   
   End Sub    
   End Class    
   
4. Event yang perlu dicegat untuk di class Form1 adalah sebagai                                                         Public Class Form1Dim sf As New clsStars
   Dim WithEvents tm As New Timer
   Private Sub Tm_Tick1(ByVal sender As Object, ByVal e
   As System.EventArgs) Handles tm.Tick
   Me.pbStars.Refresh()
   End Sub
   Private Sub Form1_FormClosing(ByVal sender As Object,
   ByVal e As System.Windows.Forms.FormClosingEventArgs)
   Handles Me.FormClosing
   sf = Nothing
   End Sub
   Private Sub Form1_Load(ByVal sender As Object, ByVal
   e As System.EventArgs) Handles Me.Load
   tm.Interval = 15
   tm.Enabled = True
   Init()
   End Sub
   Private Sub Init()
   Dim tf As Font = New Font(“KaiTi”, 100,
   FontStyle.Regular, GraphicsUnit.Pixel)
   sf.IntializeStar(11, 190, Me.Width, Me.Height)
   End Sub
   Private Sub pbStars_Paint(ByVal sender As Object,
   ByVal e As System.Windows.Forms.PaintEventArgs) Handles
   pbStars.Paint
   e.Graphics.SmoothingMode = SmoothingMode.
   AntiAlias
   sf.DrawStars(e)
   sf.DrawShip(e)
   End Sub
   End Class
5. Dijalankan, tampilan yang dida patkan adalah: