Setting OpenGL context in the dtor of a wxGLCanvas derived class

[Luca Cappa]

Hello all,

I developed a wxGLCanvas derived class, which needs to execute some OpenGL  
cleanup when it is destroyed. For this purpose I put this code in the  
destructor of my class. The problem is that I cannot set the OpenGL  
context as the current one if the wxGLCanvas's parent window is not shown:  
in fact, a call to SetCurrent() will trigger an assert at line 549 of the  
file glcanvas.cpp, whose code is shown here below:

void wxGLCanvas::SetCurrent(const wxGLContext& RC) const
{
         // although on MSW it works even if the window is still hidden, it  
doesn't
   	// under wxGTK and documentation mentions that SetCurrent() can only be
   	// called for a shown window, so check it
   	wxASSERT_MSG( GetParent()->IsShown(), _T("can't make hidden GL canvas  
current") );
....

As the comment says, this problem arises only on a wxGTK platform. To  
circumvent the assertion, since I am working on a MSW application, I set  
the GL context using this code instead:

GLCanvasDerivedClass::~GLCanvasDerivedClass ()
{
   getGLContext ()->SetCurrent (*this);
....
}

where getGLContext()'s return type is wxGLContext* .

Since this is more an hack and since it will not work (perhaps, i have not  
tryed it yet) on wxGTK, I am asking if someone could tell me a more  
sensible way to set the OGL context in the window's destructor. Or maybe  
someone could tell me how to organize my clean up differently.

TIA,
Luca