wxWidgets painting wxGLCanvas on a wxPanel

Question

I am trying to draw my wxGLCanvas in a panel and fill the area of the panel but the result is shown in the image below. I had the OpenGL cube sample running fine but in that example, the wxGLCanvas is parented to a wxFrame. When I try to parent it to a wxPanel, I get a fraction of the panel displaying my wxGLCanvas.

The red box should fill the panel in the image. Here is the constructor for my window which creates all of the stuff in the image.

wxBEGIN_EVENT_TABLE(MainWindow, wxFrame)
EVT_MENU(wxID_NEW, MainWindow::OnNewWindow)
EVT_MENU(wxID_CLOSE, MainWindow::OnClose)
wxEND_EVENT_TABLE()

MainWindow::MainWindow()
: wxFrame(NULL, wxID_ANY, wxT("OpenGL Project Test"),
wxDefaultPosition,wxDefaultSize)
{
    this->SetSizeHints( wxDefaultSize, wxDefaultSize );

    m_statusBar1 = this->CreateStatusBar( 1, wxST_SIZEGRIP, wxID_ANY );
    m_menubar1 = new wxMenuBar( 0 );
    m_menu1 = new wxMenu();
    m_menubar1->Append( m_menu1, wxT("MyMenu") ); 

    m_menu2 = new wxMenu();
    m_menubar1->Append( m_menu2, wxT("MyMenu") ); 

    m_menu3 = new wxMenu();
    m_menubar1->Append( m_menu3, wxT("MyMenu") ); 

    m_menu4 = new wxMenu();
    m_menubar1->Append( m_menu4, wxT("MyMenu") ); 

    this->SetMenuBar( m_menubar1 );

    m_toolBar4 = this->CreateToolBar( wxTB_HORIZONTAL, wxID_ANY ); 
    m_tool1 = m_toolBar4->AddTool( wxID_ANY, wxT("tool"), wxNullBitmap, wxNullBitmap,   wxITEM_NORMAL,  wxEmptyString, wxEmptyString, NULL ); 

    m_toolBar4->Realize(); 

    wxBoxSizer* bSizer1;
    bSizer1 = new wxBoxSizer( wxHORIZONTAL );

    // ######### Here is where I try to set the panel as a parent of MyGLCanvas ##########
    m_panel2 = new wxPanel( this, wxID_ANY, wxDefaultPosition, wxDefaultSize,          wxFULL_REPAINT_ON_RESIZE );
    bSizer1->Add( m_panel2, 1, wxEXPAND | wxALL, 5 );
    MyGLCanvas * glCanvas = new MyGLCanvas(m_panel2);


    m_ribbonBar2 = new wxRibbonBar( this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxRIBBON_BAR_FLOW_VERTICAL );
    m_ribbonBar2->SetArtProvider(new wxRibbonDefaultArtProvider); 
    m_ribbonPage8 = new wxRibbonPage( m_ribbonBar2, wxID_ANY, wxT("MyRibbonPage") , wxNullBitmap , 0 );
    m_ribbonPage8->SetMinSize( wxSize( 400,400 ) );

    m_ribbonPanel16 = new wxRibbonPanel( m_ribbonPage8, wxID_ANY, wxT("MyRibbonPanel") ,wxBitmap() , wxDefaultPosition, wxDefaultSize, wxRIBBON_PANEL_DEFAULT_STYLE );
    m_ribbonButtonBar7 = new wxRibbonButtonBar( m_ribbonPanel16, wxID_ANY, wxDefaultPosition, wxDefaultSize, 0 );
    m_ribbonButtonBar7->AddButton( wxID_ANY, wxT("MyRibbonButton"), wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonButtonBar7->AddButton( wxID_ANY, wxT("MyRibbonButton"), wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonButtonBar7->AddButton( wxID_ANY, wxT("MyRibbonButton"), wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonButtonBar7->AddButton( wxID_ANY, wxT("MyRibbonButton"), wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonButtonBar7->AddButton( wxID_ANY, wxT("MyRibbonButton"), wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonButtonBar7->AddButton( wxID_ANY, wxT("MyRibbonButton"), wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonPanel17 = new wxRibbonPanel( m_ribbonPage8, wxID_ANY, wxT("MyRibbonPanel") , wxNullBitmap , wxDefaultPosition, wxDefaultSize, wxRIBBON_PANEL_DEFAULT_STYLE );
    m_ribbonToolBar2 = new wxRibbonToolBar( m_ribbonPanel17, wxID_ANY, wxDefaultPosition, wxDefaultSize, 0 );
    m_ribbonToolBar2->AddTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar2->AddTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar2->AddTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar2->AddTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar2->AddTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar2->AddTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar2->AddTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonPanel18 = new wxRibbonPanel( m_ribbonPage8, wxID_ANY, wxT("MyRibbonPanel") , wxNullBitmap , wxDefaultPosition, wxDefaultSize, wxRIBBON_PANEL_DEFAULT_STYLE );
    m_ribbonToolBar3 = new wxRibbonToolBar( m_ribbonPanel18, wxID_ANY, wxDefaultPosition, wxDefaultSize, 0 );
    m_ribbonToolBar3->AddDropdownTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar3->AddHybridTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar3->AddHybridTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar3->AddHybridTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonToolBar3->AddDropdownTool( wxID_ANY, wxArtProvider::GetBitmap(wxART_QUESTION, wxART_OTHER, wxSize(32, 32)), wxEmptyString);
    m_ribbonBar2->Realize();

    bSizer1->Add( m_ribbonBar2, 0, wxALL, 5 );


    this->SetSizer( bSizer1 );
    this->Layout();

    this->Centre( wxBOTH );

    Show();

}

This is the bit thats puzzling me

m_panel2 = new wxPanel( this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxFULL_REPAINT_ON_RESIZE );
bSizer1->Add( m_panel2, 1, wxEXPAND | wxALL, 5 );
MyGLCanvas * glCanvas = new MyGLCanvas(m_panel2);

Answer 1

You never specify how should your glCanvas be laid out -- so it isn't. The simplest solution is to use a sizer for the panel and add the canvas to this sizer with proportion 1 and expand flag.