]> git.saurik.com Git - wxWidgets.git/blobdiff - src/gtk/glcanvas.cpp
Implement simple Drop, doesn't work under wxMSW (?)
[wxWidgets.git] / src / gtk / glcanvas.cpp
index d1ace2efe170cdbddb70e0d0e2502c3c5fd5fad2..c8b805cc007fcb2a079fbf427402d2adb0ab26f3 100644 (file)
@@ -1,6 +1,6 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        gtk/glcanvas.cpp
-// Purpose:     wxGLCanvas, for using OpenGL/Mesa with wxWindows and GTK
+// Name:        src/gtk/glcanvas.cpp
+// Purpose:     wxGLCanvas, for using OpenGL/Mesa with wxWidgets and GTK
 // Author:      Robert Roebling
 // Modified by:
 // Created:     17/08/98
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#ifdef __GNUG__
-#pragma implementation "glcanvas.h"
-#endif
-
-#include "wx/setup.h"
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
 
 #if wxUSE_GLCANVAS
 
 #include "wx/glcanvas.h"
 
-#include "wx/frame.h"
-#include "wx/colour.h"
-#include "wx/module.h"
-#include "wx/app.h"
-
-extern "C"
-{
-#include "gtk/gtk.h"
-#include "gdk/gdk.h"
-#include "gdk/gdkx.h"
-}
-
-#include "wx/gtk/win_gtk.h"
+#ifndef WX_PRECOMP
+    #include "wx/app.h"
+    #include "wx/frame.h"
+    #include "wx/colour.h"
+    #include "wx/module.h"
+#endif // WX_PRECOMP
 
-// DLL options compatibility check:
-#include "wx/build.h"
-WX_CHECK_BUILD_OPTIONS("wxGL")
+#include <gtk/gtk.h>
+#include <gdk/gdkx.h>
 
-//---------------------------------------------------------------------------
-// global data
-//---------------------------------------------------------------------------
-
-XVisualInfo *g_vi = (XVisualInfo*) NULL;
+#if WXWIN_COMPATIBILITY_2_8
 
 //-----------------------------------------------------------------------------
-// idle system
+// "realize" from m_wxwindow: used to create m_glContext implicitly
 //-----------------------------------------------------------------------------
 
-extern void wxapp_install_idle_handler();
-extern bool g_isIdle;
-
-//---------------------------------------------------------------------------
-// wxGLContext
-//---------------------------------------------------------------------------
-
-IMPLEMENT_CLASS(wxGLContext,wxObject)
-
-wxGLContext::wxGLContext( bool WXUNUSED(isRGB), wxWindow *win, const wxPalette& WXUNUSED(palette) )
-{
-    m_window = win;
-    m_widget = win->m_wxwindow;
-
-    wxGLCanvas *gc = (wxGLCanvas*) win;
-    XVisualInfo *vi = (XVisualInfo *) gc->m_vi;
-
-    wxCHECK_RET( vi, _T("invalid visual for OpenGl") );
-
-    m_glContext = glXCreateContext( GDK_DISPLAY(), vi, None, GL_TRUE );
-
-    wxCHECK_RET( m_glContext, _T("Couldn't create OpenGl context") );
-}
-
-wxGLContext::wxGLContext(
-               bool WXUNUSED(isRGB), wxWindow *win,
-               const wxPalette& WXUNUSED(palette),
-               const wxGLContext *other        /* for sharing display lists */
-)
-{
-    m_window = win;
-    m_widget = win->m_wxwindow;
-
-    wxGLCanvas *gc = (wxGLCanvas*) win;
-    XVisualInfo *vi = (XVisualInfo *) gc->m_vi;
-
-    wxCHECK_RET( vi, _T("invalid visual for OpenGl") );
-
-    m_glContext = glXCreateContext( GDK_DISPLAY(), vi,
-                                    other ? other->m_glContext : None,
-                                    GL_TRUE );
-
-    if ( !m_glContext )
-    {
-        wxFAIL_MSG( _T("Couldn't create OpenGl context") );
-    }
-}
-
-wxGLContext::~wxGLContext()
-{
-    if (!m_glContext) return;
-
-    if (m_glContext == glXGetCurrentContext())
-    {
-        glXMakeCurrent( GDK_DISPLAY(), None, NULL);
-    }
-
-    glXDestroyContext( GDK_DISPLAY(), m_glContext );
-}
-
-void wxGLContext::SwapBuffers()
-{
-    if (m_glContext)
-    {
-        GdkWindow *window = GTK_PIZZA(m_widget)->bin_window;
-        glXSwapBuffers( GDK_DISPLAY(), GDK_WINDOW_XWINDOW( window ) );
-    }
-}
-
-void wxGLContext::SetCurrent()
-{
-    if (m_glContext)
-    {
-        GdkWindow *window = GTK_PIZZA(m_widget)->bin_window;
-        glXMakeCurrent( GDK_DISPLAY(), GDK_WINDOW_XWINDOW(window), m_glContext );
-    }
-}
-
-void wxGLContext::SetColour(const wxChar *colour)
-{
-    float r = 0.0;
-    float g = 0.0;
-    float b = 0.0;
-    wxColour *col = wxTheColourDatabase->FindColour(colour);
-    if (col)
-    {
-        r = (float)(col->Red()/256.0);
-        g = (float)(col->Green()/256.0);
-        b = (float)(col->Blue()/256.0);
-        glColor3f( r, g, b);
-    }
-}
-
-void wxGLContext::SetupPixelFormat()
+extern "C" {
+static void
+gtk_glwindow_realized_callback( GtkWidget *WXUNUSED(widget), wxGLCanvas *win )
 {
+    win->GTKInitImplicitContext();
 }
-
-void wxGLContext::SetupPalette( const wxPalette& WXUNUSED(palette) )
-{
 }
 
-wxPalette wxGLContext::CreateDefaultPalette()
-{
-    return wxNullPalette;
-}
-
-//-----------------------------------------------------------------------------
-// "realize" from m_wxwindow
-//-----------------------------------------------------------------------------
-
-static gint
-gtk_glwindow_realized_callback( GtkWidget * WXUNUSED(widget), wxGLCanvas *win )
-{
-    wxGLContext *share= win->m_sharedContext;
-    if (share==NULL && win->m_sharedContextOf) share=win->m_sharedContextOf->GetContext();
-
-    win->m_glContext = new wxGLContext( TRUE, win, wxNullPalette, share );
-
-    return FALSE;
-}
+#endif // WXWIN_COMPATIBILITY_2_8
 
 //-----------------------------------------------------------------------------
 // "map" from m_wxwindow
 //-----------------------------------------------------------------------------
 
-static gint
+extern "C" {
+static void
 gtk_glwindow_map_callback( GtkWidget * WXUNUSED(widget), wxGLCanvas *win )
 {
-    if (win->m_glContext/* && win->m_exposed*/)
-    {
-        wxPaintEvent event( win->GetId() );
-        event.SetEventObject( win );
-        win->GetEventHandler()->ProcessEvent( event );
-
-        win->m_exposed = FALSE;
-        win->GetUpdateRegion().Clear();
-    }
+    wxPaintEvent event( win->GetId() );
+    event.SetEventObject( win );
+    win->HandleWindowEvent( event );
 
-    return FALSE;
+    win->m_exposed = false;
+    win->GetUpdateRegion().Clear();
+}
 }
 
 //-----------------------------------------------------------------------------
 // "expose_event" of m_wxwindow
 //-----------------------------------------------------------------------------
 
-static void
+extern "C" {
+static gboolean
 gtk_glwindow_expose_callback( GtkWidget *WXUNUSED(widget), GdkEventExpose *gdk_event, wxGLCanvas *win )
 {
-    if (g_isIdle)
-        wxapp_install_idle_handler();
-
-    win->m_exposed = TRUE;
+    win->m_exposed = true;
 
     win->GetUpdateRegion().Union( gdk_event->area.x,
                                   gdk_event->area.y,
                                   gdk_event->area.width,
                                   gdk_event->area.height );
+    return false;
 }
-
-//-----------------------------------------------------------------------------
-// "draw" of m_wxwindow
-//-----------------------------------------------------------------------------
-
-#ifndef __WXGTK20__
-static void
-gtk_glwindow_draw_callback( GtkWidget *WXUNUSED(widget), GdkRectangle *rect, wxGLCanvas *win )
-{
-    if (g_isIdle)
-        wxapp_install_idle_handler();
-
-    win->m_exposed = TRUE;
-
-    win->GetUpdateRegion().Union( rect->x, rect->y,
-                                  rect->width, rect->height );
 }
-#endif
 
 //-----------------------------------------------------------------------------
 // "size_allocate" of m_wxwindow
 //-----------------------------------------------------------------------------
 
+extern "C" {
 static void
-gtk_glcanvas_size_callback( GtkWidget *WXUNUSED(widget), GtkAllocation* alloc, wxGLCanvas *win )
+gtk_glcanvas_size_callback(GtkWidget *WXUNUSED(widget),
+                           GtkAllocation * WXUNUSED(alloc),
+                           wxGLCanvas *win)
 {
-    if (g_isIdle)
-        wxapp_install_idle_handler();
-
     if (!win->m_hasVMT)
         return;
 
     wxSizeEvent event( wxSize(win->m_width,win->m_height), win->GetId() );
     event.SetEventObject( win );
-    win->GetEventHandler()->ProcessEvent( event );
+    win->HandleWindowEvent( event );
+}
+}
+
+//-----------------------------------------------------------------------------
+// emission hook for "parent-set"
+//-----------------------------------------------------------------------------
+
+extern "C" {
+static gboolean
+parent_set_hook(GSignalInvocationHint*, guint, const GValue* param_values, void* data)
+{
+    wxGLCanvas* win = (wxGLCanvas*)data;
+    if (g_value_peek_pointer(&param_values[0]) == win->m_wxwindow)
+    {
+        const XVisualInfo* xvi = win->GetXVisualInfo();
+        GdkVisual* visual = gtk_widget_get_visual(win->m_wxwindow);
+        if (GDK_VISUAL_XVISUAL(visual)->visualid != xvi->visualid)
+        {
+            GdkScreen* screen = gtk_widget_get_screen(win->m_wxwindow);
+            visual = gdk_x11_screen_lookup_visual(screen, xvi->visualid);
+            GdkColormap* colormap = gdk_colormap_new(visual, false);
+            gtk_widget_set_colormap(win->m_wxwindow, colormap);
+            g_object_unref(colormap);
+        }
+        // remove hook
+        return false;
+    }
+    return true;
+}
 }
 
 //---------------------------------------------------------------------------
@@ -248,256 +130,156 @@ gtk_glcanvas_size_callback( GtkWidget *WXUNUSED(widget), GtkAllocation* alloc, w
 
 IMPLEMENT_CLASS(wxGLCanvas, wxWindow)
 
-BEGIN_EVENT_TABLE(wxGLCanvas, wxWindow)
-    EVT_SIZE(wxGLCanvas::OnSize)
-END_EVENT_TABLE()
-
-wxGLCanvas::wxGLCanvas( wxWindow *parent, wxWindowID id,
-                        const wxPoint& pos, const wxSize& size,
-                        long style, const wxString& name,
-                        int *attribList,
-                        const wxPalette& palette )
+wxGLCanvas::wxGLCanvas(wxWindow *parent,
+                       wxWindowID id,
+                       const int *attribList,
+                       const wxPoint& pos,
+                       const wxSize& size,
+                       long style,
+                       const wxString& name,
+                       const wxPalette& palette)
+#if WXWIN_COMPATIBILITY_2_8
+    : m_createImplicitContext(false)
+#endif
 {
-    Create( parent, NULL, NULL, id, pos, size, style, name, attribList, palette );
+    Create(parent, id, pos, size, style, name, attribList, palette);
 }
 
-wxGLCanvas::wxGLCanvas( wxWindow *parent,
-                        const wxGLContext *shared,
-                        wxWindowID id,
-                        const wxPoint& pos, const wxSize& size,
-                        long style, const wxString& name,
-                        int *attribList,
-                        const wxPalette& palette )
+#if WXWIN_COMPATIBILITY_2_8
+
+wxGLCanvas::wxGLCanvas(wxWindow *parent,
+                       wxWindowID id,
+                       const wxPoint& pos,
+                       const wxSize& size,
+                       long style,
+                       const wxString& name,
+                       const int *attribList,
+                       const wxPalette& palette)
+    : m_createImplicitContext(true)
 {
-    Create( parent, shared, NULL, id, pos, size, style, name, attribList, palette );
-}
+    m_sharedContext = NULL;
+    m_sharedContextOf = NULL;
 
-wxGLCanvas::wxGLCanvas( wxWindow *parent,
-                        const wxGLCanvas *shared,
-                        wxWindowID id,
-                        const wxPoint& pos, const wxSize& size,
-                        long style, const wxString& name,
-                        int *attribList,
-                        const wxPalette& palette )
-{
-    Create( parent, NULL, shared, id, pos, size, style, name, attribList, palette );
+    Create(parent, id, pos, size, style, name, attribList, palette);
 }
 
-bool wxGLCanvas::Create( wxWindow *parent,
-                         const wxGLContext *shared,
-                         const wxGLCanvas *shared_context_of,
-                         wxWindowID id,
-                         const wxPoint& pos, const wxSize& size,
-                         long style, const wxString& name,
-                         int *attribList,
-                         const wxPalette& palette)
+wxGLCanvas::wxGLCanvas(wxWindow *parent,
+                       const wxGLContext *shared,
+                       wxWindowID id,
+                       const wxPoint& pos,
+                       const wxSize& size,
+                       long style,
+                       const wxString& name,
+                       const int *attribList,
+                       const wxPalette& palette)
+    : m_createImplicitContext(true)
 {
-    m_sharedContext = (wxGLContext*)shared;  // const_cast
-    m_sharedContextOf = (wxGLCanvas*)shared_context_of;  // const_cast
-    m_glContext = (wxGLContext*) NULL;
-
-    m_exposed = FALSE;
-    m_noExpose = TRUE;
-    m_nativeSizeEvent = TRUE;
-
-    XVisualInfo *vi = NULL;
-    if (wxTheApp->m_glVisualInfo != NULL)
-    {
-        vi = (XVisualInfo *) wxTheApp->m_glVisualInfo;
-        m_canFreeVi = FALSE; // owned by wxTheApp - don't free upon destruction
-    }
-    else
-    {
-        vi = (XVisualInfo *) ChooseGLVisual(attribList);
-        m_canFreeVi = TRUE;
-    }
-    m_vi = vi;  // save for later use
-
-    wxCHECK_MSG( m_vi, FALSE, _T("required visual couldn't be found") );
-
-    GdkVisual *visual = gdkx_visual_get( vi->visualid );
-    GdkColormap *colormap = gdk_colormap_new( gdkx_visual_get(vi->visualid), TRUE );
+    m_sharedContext = const_cast<wxGLContext *>(shared);
 
-    gtk_widget_push_colormap( colormap );
-    gtk_widget_push_visual( visual );
+    Create(parent, id, pos, size, style, name, attribList, palette);
+}
 
-    wxWindow::Create( parent, id, pos, size, style, name );
+wxGLCanvas::wxGLCanvas(wxWindow *parent,
+                       const wxGLCanvas *shared,
+                       wxWindowID id,
+                       const wxPoint& pos, const wxSize& size,
+                       long style, const wxString& name,
+                       const int *attribList,
+                       const wxPalette& palette )
+    : m_createImplicitContext(true)
+{
+    m_sharedContext = NULL;
+    m_sharedContextOf = const_cast<wxGLCanvas *>(shared);
 
-    m_glWidget = m_wxwindow;
+    Create(parent, id, pos, size, style, name, attribList, palette);
+}
 
-#ifdef __WXGTK20__
-    gtk_widget_set_double_buffered( m_glWidget, FALSE );
-#endif
+#endif // WXWIN_COMPATIBILITY_2_8
 
-    gtk_pizza_set_clear( GTK_PIZZA(m_wxwindow), FALSE );
+bool wxGLCanvas::Create(wxWindow *parent,
+                        wxWindowID id,
+                        const wxPoint& pos,
+                        const wxSize& size,
+                        long style,
+                        const wxString& name,
+                        const int *attribList,
+                        const wxPalette& WXUNUSED_UNLESS_DEBUG(palette))
+{
+    wxASSERT_MSG( !palette.IsOk(), _T("palettes not supported") );
 
-    gtk_signal_connect( GTK_OBJECT(m_wxwindow), "realize",
-                            GTK_SIGNAL_FUNC(gtk_glwindow_realized_callback), (gpointer) this );
+    m_exposed = false;
+    m_noExpose = true;
+    m_nativeSizeEvent = true;
 
-    gtk_signal_connect( GTK_OBJECT(m_wxwindow), "map",
-                            GTK_SIGNAL_FUNC(gtk_glwindow_map_callback), (gpointer) this );
+    if ( !InitVisual(attribList) )
+        return false;
 
-    gtk_signal_connect( GTK_OBJECT(m_wxwindow), "expose_event",
-        GTK_SIGNAL_FUNC(gtk_glwindow_expose_callback), (gpointer)this );
+    // watch for the "parent-set" signal on m_wxwindow so we can set colormap
+    // before m_wxwindow is realized (which will occur before
+    // wxWindow::Create() returns if parent is already visible)
+    unsigned sig_id = g_signal_lookup("parent-set", GTK_TYPE_WIDGET);
+    g_signal_add_emission_hook(sig_id, 0, parent_set_hook, this, NULL);
 
-#ifndef __WXGTK20__
-    gtk_signal_connect( GTK_OBJECT(m_wxwindow), "draw",
-        GTK_SIGNAL_FUNC(gtk_glwindow_draw_callback), (gpointer)this );
-#endif
+    wxWindow::Create( parent, id, pos, size, style, name );
 
-    gtk_signal_connect( GTK_OBJECT(m_widget), "size_allocate",
-        GTK_SIGNAL_FUNC(gtk_glcanvas_size_callback), (gpointer)this );
+    gtk_widget_set_double_buffered(m_wxwindow, false);
 
-    gtk_widget_pop_visual();
-    gtk_widget_pop_colormap();
+#if WXWIN_COMPATIBILITY_2_8
+    g_signal_connect(m_wxwindow, "realize",       G_CALLBACK(gtk_glwindow_realized_callback), this);
+#endif // WXWIN_COMPATIBILITY_2_8
+    g_signal_connect(m_wxwindow, "map",           G_CALLBACK(gtk_glwindow_map_callback),      this);
+    g_signal_connect(m_wxwindow, "expose_event",  G_CALLBACK(gtk_glwindow_expose_callback),   this);
+    g_signal_connect(m_widget,   "size_allocate", G_CALLBACK(gtk_glcanvas_size_callback),     this);
 
+#if WXWIN_COMPATIBILITY_2_8
+    // if our parent window is already visible, we had been realized before we
+    // connected to the "realize" signal and hence our m_glContext hasn't been
+    // initialized yet and we have to do it now
     if (GTK_WIDGET_REALIZED(m_wxwindow))
         gtk_glwindow_realized_callback( m_wxwindow, this );
+#endif // WXWIN_COMPATIBILITY_2_8
 
     if (GTK_WIDGET_MAPPED(m_wxwindow))
         gtk_glwindow_map_callback( m_wxwindow, this );
 
-    return TRUE;
+    return true;
 }
 
-wxGLCanvas::~wxGLCanvas()
+Window wxGLCanvas::GetXWindow() const
 {
-    XVisualInfo *vi = (XVisualInfo *) m_vi;
-
-    if (vi && m_canFreeVi) XFree( vi );
-    if (m_glContext) delete m_glContext;
-}
-
-void* wxGLCanvas::ChooseGLVisual(int *attribList)
-{
-    int data[512];
-    if (!attribList)
-    {
-        // default settings if attriblist = 0
-        data[0] = GLX_RGBA;
-        data[1] = GLX_DOUBLEBUFFER;
-        data[2] = GLX_DEPTH_SIZE;   data[3] = 1;
-        data[4] = GLX_RED_SIZE;     data[5] = 1;
-        data[6] = GLX_GREEN_SIZE;   data[7] = 1;
-        data[8] = GLX_BLUE_SIZE;    data[9] = 1;
-        data[10] = GLX_ALPHA_SIZE;  data[11] = 0;
-        data[12] = None;
-
-        attribList = (int*) data;
-    }
-    else
-    {
-      int arg=0, p=0;
-
-      while( (attribList[arg]!=0) && (p<510) )
-      {
-        switch( attribList[arg++] )
-        {
-          case WX_GL_RGBA: data[p++] = GLX_RGBA; break;
-          case WX_GL_BUFFER_SIZE:
-            data[p++]=GLX_BUFFER_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_LEVEL:
-            data[p++]=GLX_LEVEL; data[p++]=attribList[arg++]; break;
-          case WX_GL_DOUBLEBUFFER: data[p++] = GLX_DOUBLEBUFFER; break;
-          case WX_GL_STEREO: data[p++] = GLX_STEREO; break;
-          case WX_GL_AUX_BUFFERS:
-            data[p++]=GLX_AUX_BUFFERS; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_RED:
-            data[p++]=GLX_RED_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_GREEN:
-            data[p++]=GLX_GREEN_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_BLUE:
-            data[p++]=GLX_BLUE_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_ALPHA:
-            data[p++]=GLX_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_DEPTH_SIZE:
-            data[p++]=GLX_DEPTH_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_STENCIL_SIZE:
-            data[p++]=GLX_STENCIL_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_ACCUM_RED:
-            data[p++]=GLX_ACCUM_RED_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_ACCUM_GREEN:
-            data[p++]=GLX_ACCUM_GREEN_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_ACCUM_BLUE:
-            data[p++]=GLX_ACCUM_BLUE_SIZE; data[p++]=attribList[arg++]; break;
-          case WX_GL_MIN_ACCUM_ALPHA:
-            data[p++]=GLX_ACCUM_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
-          default:
-            break;
-        }
-      }
-      data[p] = 0;
-
-      attribList = (int*) data;
-    }
-
-
-    Display *dpy = GDK_DISPLAY();
-
-    return glXChooseVisual( dpy, DefaultScreen(dpy), attribList );
-}
-
-void wxGLCanvas::SwapBuffers()
-{
-    if (m_glContext)
-        m_glContext->SwapBuffers();
-}
-
-void wxGLCanvas::OnSize(wxSizeEvent& WXUNUSED(event))
-{
-}
-
-void wxGLCanvas::SetCurrent()
-{
-    if (m_glContext)
-        m_glContext->SetCurrent();
-}
-
-void wxGLCanvas::SetColour( const wxChar *colour )
-{
-    if (m_glContext)
-        m_glContext->SetColour( colour );
+    GdkWindow *window = m_wxwindow->window;
+    return window ? GDK_WINDOW_XWINDOW(window) : 0;
 }
 
 void wxGLCanvas::OnInternalIdle()
 {
-    if (m_glContext && m_exposed)
+    if (m_exposed)
     {
         wxPaintEvent event( GetId() );
         event.SetEventObject( this );
-        GetEventHandler()->ProcessEvent( event );
+        HandleWindowEvent( event );
 
-        m_exposed = FALSE;
+        m_exposed = false;
         GetUpdateRegion().Clear();
     }
 
     wxWindow::OnInternalIdle();
 }
 
+#if WXWIN_COMPATIBILITY_2_8
 
-
-//---------------------------------------------------------------------------
-// wxGLApp
-//---------------------------------------------------------------------------
-
-IMPLEMENT_CLASS(wxGLApp, wxApp)
-
-wxGLApp::~wxGLApp()
-{
-    if (m_glVisualInfo)
-        XFree(m_glVisualInfo);
-}
-
-bool wxGLApp::InitGLVisual(int *attribList)
+void wxGLCanvas::GTKInitImplicitContext()
 {
-    if (m_glVisualInfo)
-        XFree(m_glVisualInfo);
-
-    m_glVisualInfo = wxGLCanvas::ChooseGLVisual(attribList);
+    if ( !m_glContext && m_createImplicitContext )
+    {
+        wxGLContext *share = m_sharedContext;
+        if ( !share && m_sharedContextOf )
+            share = m_sharedContextOf->m_glContext;
 
-    return m_glVisualInfo != NULL;
+        m_glContext = new wxGLContext(this, share);
+    }
 }
 
-#endif
-    // wxUSE_GLCANVAS
+#endif // WXWIN_COMPATIBILITY_2_8
 
+#endif // wxUSE_GLCANVAS