GUI in Visual Basic

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GUI in Visual Basic

Post by Edmund » Fri Feb 27, 2009 5:47 pm

Hello, I am trying to write a GUI for my engine in Visual Basic 6. Unfortunately I can't get the communication code right.
I managed to load the engine and receive the first couple of lines from the engine. Then I tried to send the "uci" command from the GUI to the Engine but I am not getting any response. Because receiving is working at the beginning I assume that the problem lies within the send code.

I took the main structure from winboard.c and translated it to Visual Basic code. Am I missing anything?

Code: Select all

Public Sub EngineRun()

    Dim start As STARTUPINFO
    Dim L As Long, Result As Long, bSuccess As Long
    Dim Buffer As String
    sa.nLength = Len(sa)
    sa.bInheritHandle = 1&
    sa.lpSecurityDescriptor = 0&
    Result = CreatePipe(hChildStdoutRd, hChildStdoutWr, sa, 1024 * 16)
    Result = DuplicateHandle(GetCurrentProcess(), hChildStdoutRd, _
                 GetCurrentProcess(), hChildStdoutRdDup, 0, _
                 False, DUPLICATE_SAME_ACCESS)
    If Result = 0 Then
        MsgBox "CreatePipe failed Error!"
        Exit Sub
    End If
    CloseHandle hChildStdoutRd
    Result = CreatePipe(hChildStdinRd, hChildStdinWr, sa, 0)

    Result = DuplicateHandle(GetCurrentProcess(), hChildStdinWr, _
                 GetCurrentProcess(), hChildStdinWrDup, 0, _
                 False, DUPLICATE_SAME_ACCESS)
    If Result = 0 Then
        MsgBox "CreatePipe failed Error!"
        Exit Sub
    End If
    CloseHandle hChildStdinWr

    start.cb = Len(start)
    start.dwFlags = STARTF_USESTDHANDLES
    start.hStdInput = hChildStdinRd
    start.hStdOutput = hChildStdoutWr
    start.hStdError = hChildStdoutWr

    Result = CreateProcessA(0&, EnginePath, 0&, 0&, 1&, &H8000000, 0&, 0&, start, proc)
    ProcID = proc.hProcess

    If Result <> 0 Then
        Dim lPeekData As Long
            Call PeekNamedPipe&#40;hChildStdoutRdDup, ByVal 0&, 0&, ByVal 0&, lPeekData, ByVal 0&)
            If lPeekData > 0 Then
                Buffer = Space$&#40;lPeekData&#41;
                bSuccess = readFile&#40;hChildStdoutRdDup, Buffer, Len&#40;Buffer&#41;, L, 0&)
                If bSuccess = 1 Then
                    MsgBox "ReadFile failed!"
                End If
                bSuccess = WaitForSingleObject&#40;proc.hProcess, 0&)
                If bSuccess = 0 Then Exit Do
            End If
        MsgBox "Error while starting process!"
    End If
    TerminateProcess proc.hProcess, 0
    Call CloseHandle&#40;proc.hProcess&#41;
    Call CloseHandle&#40;proc.hThread&#41;
    Call CloseHandle&#40;hReadPipe&#41;
    Call CloseHandle&#40;hWritePipe&#41;

End Sub

Public Sub EngineSend&#40;)
    Dim b&#40;256&#41;
    Dim data As String
    data = "uci" & vbCrLf
    Call CopyMemory&#40;b&#40;0&#41;, data, Len&#40;data&#41;)

    fSuccess = WriteFile&#40;hChildStdinWrDup, b&#40;0&#41;, Len&#40;data&#41;, lBytesWritten, 0&#41;
    'FlushFileBuffers hChildStdinWrDup
End Sub
The additional FlushFileBuffers in the end didn't make any difference.


Re: GUI in Visual Basic

Post by andretaff » Fri Feb 27, 2009 8:56 pm


Maybe you should check the fSucess flag. One thing you can do for testing is changing your engine so everything that is received is sent back. This way you'll see if something at all is coming to the engine.

Just curious: why writing a new GUI?
I have thought about writing a good GUI for Linux, but just because I couldn't find a good one. There was knights, but the project seems dead.

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Bill Rogers
Posts: 3562
Joined: Thu Mar 09, 2006 2:54 am
Location: San Jose, California

Re: GUI in Visual Basic

Post by Bill Rogers » Fri Feb 27, 2009 9:59 pm

A friend in New Zeland or Australis sent me the Winboard code to make my basic program work. I'll send that code to you as soon as I can isolate it from my program.
For your information, I also wrote my own graphics program for a chess program and have a simple code available for it.


Re: GUI in Visual Basic

Post by Tommy » Sat Feb 28, 2009 12:32 am

I'm not sure what is wrong with your code, maybe the vbCrLf you send is causing an issue with the engine trying to interpret the command. Because you are sending a carriage return and a line feed character.

Anyway, here is my code written in FreeBASIC, you can use this for comparison...

Code: Select all

' Pseudo Winboard chess program written by Thomas McBurney August 2005
'The following code is only an example of how to communicate with
'Winboard using a pipe.  

' Declare my functions and subs.  FreeBASIC gets upset if I don't do it.
declare function GetCommand&#40;) as string
declare function SendCommand&#40;byval WBCmd as string&#41; as integer
declare sub Main

' Declare the API functions we will be using for communicating to Winboard
dim KernelLib as integer
dim shared WriteFile as function &#40;BYVAL hFile AS integer, lpBuffer AS ANY, BYVAL nNumberOfBytesToWrite AS integer, lpNumberOfBytesWritten AS integer, lpOverlapped AS ANY&#41; AS integer
dim shared GetStdHandle as function &#40;BYVAL nStdHandle AS integer&#41; AS integer
dim shared ReadFile as function &#40;BYVAL hFile AS integer, lpBuffer AS ANY, BYVAL nNumberOfBytesToRead AS integer, lpNumberOfBytesRead AS integer, lpOverlapped AS ANY&#41; AS integer
dim shared PeekNamedPipe as function &#40;BYVAL hNamedPipe AS integer, lpBuffer AS ANY, BYVAL nBufferSize AS integer, lpBytesRead AS integer, lpTotalBytesAvail AS integer, lpBytesLeftThisMessage AS integer&#41; AS integer

' Link KernelLib to kernel32.dll
KernelLib = dylibload&#40; "KERNEL32" )

' Link the functions to the appropriate Kernel32 library.
WriteFile = dylibsymbol&#40; KernelLib, "WriteFile" )
GetStdHandle = dylibsymbol&#40; KernelLib, "GetStdHandle" )
ReadFile = dylibsymbol&#40; KernelLib, "ReadFile" )
PeekNamedPipe = dylibsymbol&#40; KernelLib, "PeekNamedPipe" )

 DIM shared OutputHandle AS integer
 DIM shared InputHandle AS integer

 OutputHandle = GetStdHandle&#40;STD_OUTPUT_HANDLE&#41;
 InputHandle = GetStdHandle&#40;STD_INPUT_HANDLE&#41;
 call Main

sub Main

dim sWinboardCmd as string
dim sTemp as string

    sWinboardCmd=GetCommand ' Get command from Winboard
    if sWinboardCmd<>"" then
        IF sWinboardCmd="protover 2" THEN
            sTemp="feature myname="+CHR$&#40;34&#41;+"Pseudo chess program written in FreeBASIC"+CHR$&#40;34&#41;
            SendCommand&#40;"feature done=1")
        END IF

        IF sWinboardCmd="quit" THEN EXIT DO ' this will exit the program
        IF sWinboardCmd="e2e4" THEN SendCommand&#40;"move e7e5")
        IF sWinboardCmd="g1f3" THEN SendCommand&#40;"move b8c6")
    END IF
    sleep 10


function GetCommand&#40;) as string

    'This function will retrieve one command at a time from winboard.

    DIM iBytesRead AS integer
    DIM iTotalBytes AS integer
    DIM iAvailBytes AS integer
    DIM iReturnCode AS integer
    DIM sTemp as string

    ' Null character will make sBuff a C style empty string
    sBuff = CHR$&#40;0&#41; 
    ' PeekNamedPipe tells us if there is any data waiting to be retrieved.
     iReturnCode = PeekNamedPipe&#40;InputHandle, BYVAL STRPTR&#40;sBuff&#41;, 1, iBytesRead, iTotalBytes, iAvailBytes&#41;

    ' return empty string when there is no data to be retrieved.
    IF iTotalBytes=0 THEN EXIT function

    ' Retrieve data
        iReturnCode = ReadFile&#40;InputHandle, BYVAL STRPTR&#40;sBuff&#41;, 1, iBytesRead, BYVAL 0&) 
        IF ASC&#40;sBuff&#41;=10 THEN EXIT DO  ' exit on line feed
END function

Function SendCommand&#40;Byval sWBCmd As String&#41; As integer

    Dim iBytesWritten As integer
    Dim iBytes As integer
    Dim iReturnCode As integer
    sWBCmd = sWBCmd + chr$&#40;10&#41; ' add line feed to end of string
    iBytes = Len&#40;sWBCmd&#41;
    iReturnCode = WriteFile&#40;OutputHandle, ByVal sWBCmd, iBytes, lBytesWritten, ByVal 0&)

    SendCommand = 0

End Function

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Re: GUI in Visual Basic

Post by hgm » Sat Feb 28, 2009 7:29 am

You could use the InBetween adapter to get a real-time log of what goes both ways, to see if you have a buffering problem, and where you get stuck.

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Re: GUI in Visual Basic

Post by Edmund » Sat Feb 28, 2009 12:06 pm

Thanks to all!

Changing vbcrlf to vblf solved the problem
andretaff wrote: Just curious: why writing a new GUI?
I just created an own opening book format and now wanted to add engine analysis to the opening book creation program

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