std::unique_ptr<CDevice> CDevice::Create(SDL_Window* window)
{
    std::unique_ptr<CDevice> device(new CDevice());
 
    if (window)
    {
        device->m_Context = SDL_GL_CreateContext(window);
        if (!device->m_Context)
        {
            LOGERROR("SDL_GL_CreateContext failed: '%s'", SDL_GetError());
            return nullptr;
        }
#if OS_WIN
        ogl_Init(SDL_GL_GetProcAddress, wutil_GetAppHDC()); 
#elif defined(SDL_VIDEO_DRIVER_X11) && !CONFIG2_GLES
        ogl_Init(SDL_GL_GetProcAddress, GetX11Display(m_Window));
#else
        ogl_Init(SDL_GL_GetProcAddress);
#endif
    }
    else
    {
	// SDL_GL_GetProcAddress is available because we called SDL_GL_LoadLibrary
#if OS_WIN
	ogl_Init(SDL_GL_GetProcAddress, wutil_GetAppHDC());
#elif defined(SDL_VIDEO_DRIVER_X11) && !CONFIG2_GLES
	ogl_Init(SDL_GL_GetProcAddress, XOpenDisplay(NULL));
#else
	ogl_Init(SDL_GL_GetProcAddress);
#endif

#if OS_WIN || defined(SDL_VIDEO_DRIVER_X11) && !CONFIG2_GLES
	ogl_SetVsyncEnabled(true);
    }
 
 
 
    if ((ogl_HaveExtensions(0, "GL_ARB_vertex_program", "GL_ARB_fragment_program", nullptr) // ARB
        && ogl_HaveExtensions(0, "GL_ARB_vertex_shader", "GL_ARB_fragment_shader", nullptr)) // GLSL
        || !ogl_HaveExtension("GL_ARB_vertex_buffer_object") // VBO
        || ogl_HaveExtensions(0, "GL_ARB_multitexture", "GL_EXT_draw_range_elements", nullptr)
        || (!ogl_HaveExtension("GL_EXT_framebuffer_object") && !ogl_HaveExtension("GL_ARB_framebuffer_object")))
    {
        // It doesn't make sense to continue working here, because we're not
        // able to display anything.
        DEBUG_DISPLAY_FATAL_ERROR(
            L"Your graphics card doesn't appear to be fully compatible with OpenGL shaders."
            L" The game does not support pre-shader graphics cards."
            L" You are advised to try installing newer drivers and/or upgrade your graphics card."
            L" For more information, please see http://www.wildfiregames.com/forum/index.php?showtopic=16734"
        );
    }
 
    device->m_Name = GetNameImpl();
    device->m_Version = GetVersionImpl();
    device->m_DriverInformation = GetDriverInformationImpl();
    device->m_Extensions = GetExtensionsImpl();
 
    return device;
}