Help needed, C -> PB translation

[Rav Singh]

Hi,

I'm not a C expert, I need help translating the following OpenGL statement (from Microsoft's gl.h) to PowerBasic :-

	typedef void (APIENTRY * PFNGLARRAYELEMENTEXTPROC) (GLint i);

Thanks,

- Rav.



[This message has been edited by Rav Singh (edited December 30, 2004).]

[Uwe Heyer]

Hi Rav,

typedef void (APIENTRY * PFNGLARRAYELEMENTEXTPROC) (GLint i);

this is the declaration of a typed variable for function calls.

void APIENTRY GlArrayElementText(Glint i);
SUB SDECL name of a func (BYVAL integer i)

with variable PFNGLARRAYELEMENTEXTPROC you can only call functions declared as above

In PB you would code something like (copy&paste from help)

DECLARE SUB MySubCall(Param1%, Param2%)
DIM PtrMySubCall AS DWORD
PtrMySubCall= CODEPTR(MySubCall)
CALL DWORD PtrMySubCall USING MySubCall(x1%, x2%)

Ahoj
-Uwe


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[Rav Singh]

Hi Uwe ,I think I understand what's it's trying to do, thanks for your help.

- Rav.

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[Uwe Heyer]

Hi Rav,

here some sample code that I use for detecting that my app run as Terminal-Server-Session
(below is far off completed :-)

sample show how C++ call pfnVar(..)
PB: CALL DWORD ptr USING DeclaredFunc(..)

API WTSOpenServer is only on WTS computers available, so I can't use static binding to those API calls

// declaration in sample.h
typedef HANDLE (WINAPI * API_WTSOPENSERVER) (LPTSTR pszServerName);

// code in sample.cpp
// we need some variables
HINSTANCE hWtsApi32;
API_WTSOPENSERVER pfnWTSOpenServer; // see declaration
HANDLE hServer;

// LoadLibrary
hWtsApi32 = LoadLibrary(TEXT("WTSAPI32.DLL"));
// Get Address of API Function
pfnWTSOpenServer = (API_WTSOPENSERVER) GetProcAddress(hWtsApi32, TEXT("WTSOpenServerA"));
// call it
hServer = pfnWTSOpenServer(pszComputerName); // see declaration

I think you got the idea when you see such code and how to translate it to PowerBasic

Ahoj
-Uwe

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[This message has been edited by Uwe Heyer (edited December 31, 2004).]