Pong

[GingerNut]

Yes, it's yet another Pong Game.

I'm writing a pong program for a VB course I'm doing. I've got the two paddles moving up and down in a picture box but how do I keep them from disappearing off the screen?

[SLH]

Are you moving the ball using vectors,

X=X+A
Y=Y+B

Or using angles?

X=X+(Sin(Angle)*Speed)
Y=Y+(Cos(Angle)*Speed)

The first is easier (for starting anyway), you'd do something like this (example is for the top paddle (has the lowest y value as the origin is at the top left):
X, Y is the position of the picbox (it's origin is also top left), and a and b are the speed vectors to add to them to create movement.

If Ball.Y < paddle.Y + paddle.Height And Ball.X + Ball.Width > paddle.X And Ball.X < paddle.X + paddle.Width Then
    'Ball hit the paddle, so change it's y direction (a way from the paddle)
    Ball.B = -Abs(Ball.B)
    'Could manipulate the Ball.A value here according to where the ball hit the pad.
End If

Here is the code if you're using the angle & speed method:

If Ball.Y < paddle.Y + paddle.Height And Ball.X + Ball.Width > paddle.X And Ball.X < paddle.X + paddle.Width Then
    Ball.Angle = 90-(Ball.Angle-270)
    'Note: This will be different for all other collisions
End If

[SLH]

For a lot more info, and stuff that will get you the best grade check out this thread:

http://www.vbforums.com/showthread.p...hreadid=163044

[GingerNut]

Thanks, I'll go check it out.

[GingerNut]

I have another little prob not covered by the other thread. I want to play a sound everytime the ball hits the walls. I've used this code:

If BallX < 0 Then
BallX = 0
BallXDir = 1
RtnValue = sndPlaySound(Bounce, SND_ASYNC Or SND_MEMORY)

The sound has been stored here:

Dim Buffer As String
Dim F As Integer
Dim SoundBuffer As String
On Error GoTo NoiseGet_Error
Buffer = Space(1024)
SoundBuffer = ""
F = FreeFile
Open FileName For Binary As F
Do While Not EOF(F)
Get #F, , Buffer
SoundBuffer = SoundBuffer & Buffer
Loop
Close F
StoreSound = Trim(SoundBuffer)
Exit Function
NoiseGet_Error:
SoundBuffer = ""
Exit Function

And in the form load:
Bounce = StoreSound(App.Path + "Bounce.wav")

I think I've declared everything I should:

Private Declare Function sndPlaySound Lib "winmm.dll" Alias "sndPlaySoundA" (ByVal lpszSoundName As String, ByVal uFlags As Long) As Long
Private Const SND_ASYNC = &H1
Private Const SND_SYNC = &H0
Private Const SND_MEMORY = &H4


But the sound won't play. Can you see where I might have gone wrong? Maybe I left something out.

[SLH]

If the ball is changing direction correctly, then the problem is with your sound code, as i havn't used sound before i can't help you

[GingerNut]

OK, Thanks anyway