Pong question

[mpie]

I'm trying to program pong in vb.net but I can't get the ball on the screen. I use the solidbrush method to draw a ball and the timer event with refresh. I know it has something to do with the paint event but I don't know the exact code. I've got something like this :

    Private dirUp As Boolean
   Private dirLeft As Boolean
   Private ballHeight As Integer = 10
   Private ballWidth As Integer = 10
   Private ballColor As New SolidBrush(Color.DarkKhaki)
   Private ballX As Integer
   Private ballY As Integer
   Private maxHeight As Integer
   Private maxWidth As Integer

   Sub Tekenbal(ByVal e As System.Windows.Forms.DrawItemEventArgs)

       Me.CreateGraphics.SmoothingMode = Drawing.Drawing2D.SmoothingMode.AntiAlias
       Me.CreateGraphics.SmoothingMode = Drawing.Drawing2D.SmoothingMode.HighSpeed

       e.Graphics.FillEllipse(ballColor, 10, 10, 10, 10)
   End Sub

   Sub Beweegbal()
       If dirUp = True Then
           ballY = ballY - 10
       Else
           ballY = ballY + 10
       End If

       If dirLeft = True Then
           ballX = ballX - 10
       ElseIf Not dirLeft Then
           ballX = ballX + 10
       End If

       If ballHeight + ballY >= maxHeight Then
           dirUp = True 'Weer naar boven
       Else
           dirUp = False
       End If

       If ballWidth + ballX >= maxWidth Then
           dirLeft = True 'Naar links
       Else
           dirLeft = False
       End If

       If ballY <= 0 Then
           dirUp = True 'Naar beneden
       End If

       If ballX <= 0 Then
           dirLeft = True 'Naar rechts
       End If
   End Sub

   Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
       Me.Refresh()
       Tekenbal(e) 'It says System.Windows.Forms.PaintEventArgs cannot be converted to System.Windows.Forms.DrawItemEventArgs
   End Sub

   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
       maxWidth = Me.Width
       maxHeight = Me.Height - 30
   End Sub

   Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
       Tekenbal(e) 'It says System.Windows.Forms.PaintEventArgs cannot be converted to System.Windows.Forms.DrawItemEventArgs
       Beweegbal()
   End Sub

[mutant]

Make your Tekenbal sub accept PaintEventArgs, not draw item event args. Dont use Me.CreateGraphics.smoothingmode. Use e.Graphics.SmoothingMode, after you pass in the paint event args from Paint event. Also in your timer, you try to pass in e, which I dont see you declaring anywhere in that sub, but you dont need this, Me.Refresh will call your paint event which contains the same thing.

[mpie]

Make your Tekenbal sub accept PaintEventArgs, not draw item event args. Dont use Me.CreateGraphics.smoothingmode. Use e.Graphics.SmoothingMode, after you pass in the paint event args from Paint event. Also in your timer, you try to pass in e, which I dont see you declaring anywhere in that sub, but you dont need this, Me.Refresh will call your paint event which contains the same thing.

Thank you very much I can see the ball now :)

[mpie]

I think something went wrong because the ball isn't moving.

[mutant]

Is that dirUp or dirLeft is supposed to do?

 

Use the KeyDown event on your form to capture keys, then check what key was pressed like this:

If e.KeyCode = Keys.Left Then 'for example if you want
'to check if left arrow was pressed.

And you also have to change the coordinates of your ellipse, right now you are drawing in the same place all the time, (10,10). Make those two values a variable, and increase it or decrease it when someone presses a button and then refresh your form.

[mpie]

Is that dirUp or dirLeft is supposed to do?

 

Use the KeyDown event on your form to capture keys, then check what key was pressed like this:

If e.KeyCode = Keys.Left Then 'for example if you want
'to check if left arrow was pressed.

And you also have to change the coordinates of your ellipse, right now you are drawing in the same place all the time, (10,10). Make those two values a variable, and increase it or decrease it when someone presses a button and then refresh your form.

The ball is now moving. The dirUp and dirLeft is to check if the ball hits the wall.

My source is now :

Private dirUp As Boolean
   Private dirLeft As Boolean
   Private ballHeight As Integer = 10
   Private ballWidth As Integer = 10
   Private ballColor As New SolidBrush(Color.MediumSlateBlue)
   Private ballXpositie As Integer = 20
   Private ballYpositie As Integer = 20
   Private maxHeight As Integer
   Private maxWidth As Integer

   Sub Tekenbal(ByVal e As System.Windows.Forms.PaintEventArgs)
       e.Graphics.SmoothingMode = Drawing.Drawing2D.SmoothingMode.AntiAlias
       e.Graphics.SmoothingMode = Drawing.Drawing2D.SmoothingMode.HighSpeed
       e.Graphics.FillEllipse(ballColor, ballXpositie, ballYpositie, ballHeight, ballWidth)
   End Sub

   Sub Beweegbal()

       If dirUp = True Then
           ballYpositie -= 10
       Else
           ballYpositie += 10
       End If

       If dirLeft = True Then
           ballXpositie -= 10
       Else
           ballXpositie += 10
       End If

       If ballHeight + ballYpositie >= maxHeight Then
           dirUp = True 'going up
       Else
           dirUp = False
       End If

       If ballWidth + ballXpositie >= maxWidth Then
           dirLeft = True 'going left
       Else
           dirLeft = False
       End If

       If ballYpositie <= 0 Then
           dirUp = False 'going down
       Else
           dirUp = True
       End If

       If ballXpositie <= 0 Then
           dirLeft = False 'going right
       Else
           dirLeft = True
       End If
   End Sub

   Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
       Me.Refresh()
   End Sub

   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
       maxWidth = Me.Width
       maxHeight = Me.Height - 30
   End Sub

   Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
       Tekenbal(e)
       Beweegbal()
   End Sub

The ball keeps bouncing up/left and down/right without hitting the wall. And when I change the true and false with each other the ball went straight through the wall. :eek: I'm getting frustrated here.

[mpie]

Nevermind I've fixed it allready :)

[BooGhost]

It hurts to see this kinda code.

 

consider:

 

' Assume user capable of creating Ball and Wall objects

private theBall as Ball

private theWall as Wall

 

 

' Timer event painting removed for clarity.. moving on to direction setting.

 

If (theBall.X <= theWall.Left) OR (theWall.Right <= theBall.X) then

theBall.XDirection = theBall.XDirection * -1

End If

 

If (theBall.Y <= theWall.Top) OR (theWall.Bottom <= theBall.Y) Then

theball.YDirection = theBall.YDirection * -1

End If

[hog]

Also consider :

 

Getting a copy of .NET Game Programming With DirectX 9.0

 

It starts off by covering stuff you are doing not prior to getting stuck into how to use DirectX.

 

I've said it before and I'll say it again.....it's a bloody good book:)

[mpie]

Also consider :

 

Getting a copy of .NET Game Programming With DirectX 9.0

 

It starts off by covering stuff you are doing not prior to getting stuck into how to use DirectX.

 

I've said it before and I'll say it again.....it's a bloody good book:)

Thanx I'll look for it at our bookstore