Keskustelu: Koodit: VB.NET: Lensflare -imaget algoritmein

Public Class frmFlare
    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 picSurface As System.Windows.Forms.PictureBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.picSurface = New System.Windows.Forms.PictureBox
        Me.SuspendLayout()
        '
        'picSurface
        '
        Me.picSurface.Location = New System.Drawing.Point(0, 0)
        Me.picSurface.Name = "picSurface"
        Me.picSurface.Size = New System.Drawing.Size(376, 320)
        Me.picSurface.TabIndex = 0
        Me.picSurface.TabStop = False
        '
        'frmFlare
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(376, 318)
        Me.Controls.Add(Me.picSurface)
        Me.Name = "frmFlare"
        Me.Text = "LensFlare"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub frmFlare_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ' pääbittikartta
        Dim b As New Bitmap(picSurface.Width, picSurface.Height)
        Dim g As Graphics = Graphics.FromImage(b)
        ' säde
        Dim rad As Double
        ' counttereita
        Dim x, y, i, a As Integer
        ' värit
        Dim c1, c2, c3, c4 As Double
        'taulukko spark emitter kuviota varten
        Dim bi(b.Width, b.Height) As Double

        ' kuvio mapit
        Dim b1 As New Bitmap(111, 111)
        Dim b2 As New Bitmap(111, 111)
        Dim b3 As New Bitmap(111, 111)
        Dim b4 As New Bitmap(111, 111)

        ' partikkelien määrä
        For i = 0 To 100
            Dim angle As Double = Rnd() * 2 * Math.PI
            Dim dx As Double = Math.Cos(angle)
            Dim dy As Double = Math.Sin(angle)
            Dim fx As Double = 50
            Dim fy As Double = 50
            ' trailien pituus
            For a = 0 To 40
                For y = -1 To 1
                    For x = -1 To 1
                        Dim r2 As Double = x * x + y * y
                        ' partikkelin kaava
                        c1 = 1 - r2 / (2 * 2)
                        c1 = c1 * c1
                        c1 = c1 * c1
                        ' Lisätään väri taulukkoon partikkelin väri(blendauksen takia)
                        bi(x + fx, y + fy) += c1 / a
                    Next
                Next
                fx += dx
                fy += dy
            Next
        Next
        ' renderöi spark emitteri
        For x = 1 To 110
            For y = 1 To 110
                If bi(x, y) > 1 Then bi(x, y) = 1
                b1.SetPixel(x, y, Color.FromArgb(bi(x, y) * 255, bi(x, y) * 255, bi(x, y) * 255))
            Next
        Next

        Dim R As Double = Math.Min(b2.Width, b2.Height) / 2
        For x = 1 To 110
            For y = 1 To 110
                Dim dx As Integer = R - x
                Dim dy As Integer = R - y
                rad = Math.Sqrt(dx * dx + dy * dy) / R
                ' (1-r)^2
                c2 = 1 - rad
                c2 = c2 * c2
                c2 *= 1 - pehmennys(1 - 0.01, 1 + 0.01, rad)
                ' r
                c3 = rad
                c3 *= 1 - pehmennys(1 - 0.01, 1 + 0.01, rad)
                ' r^6
                c4 = rad * rad
                c4 = c4 * c4
                c4 = c4 * c4 * c4
                c4 *= 1 - pehmennys(1 - 0.01, 1 + 0.01, rad)

                ' piirretään pikseli
                b2.SetPixel(x, y, Color.FromArgb(c2 * 255, c2 * 255, c2 * 255))
                b3.SetPixel(x, y, Color.FromArgb(c3 * 255, c3 * 255, c3 * 255))
                b4.SetPixel(x, y, Color.FromArgb(c4 * 255, c4 * 255, c4 * 255))
            Next
        Next
        g.DrawImage(b1, 0, 0)
        g.DrawImage(b2, 120, 0)
        g.DrawImage(b3, 240, 0)
        g.DrawImage(b4, 0, 120)
        picSurface.BackgroundImage = b
    End Sub

    ' Kätevä pehmennys funktio
    Function pehmennys(ByVal a, ByVal b, ByVal x)
        If x < a Then Return 0
        If x >= b Then Return 1
        x = (x - a) / (b - a)
        Return (x * x) * (3 - 2 * x)
    End Function
End Class