any OpenGL function address

void *GetAnyGLFuncAddress(const char *name)
{
  void *p = (void *)wglGetProcAddress(name);
  if(p == 0 ||
    (p == (void*)0x1) || (p == (void*)0x2) || (p == (void*)0x3) ||
    (p == (void*)-1) )
  {
    HMODULE module = LoadLibraryA("opengl32.dll");
    p = (void *)GetProcAddress(module, name);
  }

  return p;
}