Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Message-ID: <42DE917E.45C144FC@dessent.net> Date: Wed, 20 Jul 2005 11:01:34 -0700 From: Brian Dessent MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: g++ problem when attempting to cast a function pointer in an OpenGL GLU callback References: <1075213EFAF9BA4181A250B072635947F14C8A@AMR-EX6.ds.amrdec.army.mil> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Spam-Report: -5.9/5.0 ---- Start SpamAssassin results * -3.3 ALL_TRUSTED Did not pass through any untrusted hosts * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * 0.0 AWL AWL: From: address is in the auto white-list ---- End SpamAssassin results X-IsSubscribed: yes Reply-To: cygwin@cygwin.com "Day, Michael A AMRDEC/UAH" wrote: > test.cpp:72: error: invalid conversion from `void (*)()' to `void (*)()' Win32 API functions generally use the stdcall calling convention, not the standard C one. Your tcbBegin is not defined this way and this could be what the compiler is trying to tell you, although the error certainly isn't very clear. If you look at glu.h: GLAPI void APIENTRY gluTessCallback (GLUtesselator* tess, GLenum which, _GLUfuncptr CallBackFunc); where _GLUfuncptr is defined as: typedef void (APIENTRY *_GLUfuncptr)(); where APIENTRY expands to "__attribute__ ((__stdcall__))". So you'll need to declare your callback with that attribute or else it will not work. Brian -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/