Writing a Platform and GUI Toolkit Independent OpenGL Class

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <gtk/gtk.h>

#include "callbacks.h"
#include "interface.h"
#include "support.h"

#include <GLView.h>

static CGLView *pGLView = NULL;

void
UpdateDrawingArea (GtkWidget * widget)
{
  GtkWidget *drw = lookup_widget (GTK_WIDGET (widget), "drawingarea1");
  gdk_window_invalidate_rect (GTK_WIDGET (drw)->window,
			      &GTK_WIDGET (drw)->allocation, FALSE);
}

void
on_new1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_open1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_save1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_save_as1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_quit1_activate (GtkMenuItem * menuitem, gpointer user_data)
{
  if (pGLView)
    {
      delete pGLView;
      pGLView = NULL;
    }
  gtk_main_quit ();
}


void
on_cut1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_copy1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_paste1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_delete1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}


void
on_about1_activate (GtkMenuItem * menuitem, gpointer user_data)
{

}

#ifdef WIN32
#include <gdk/gdkwin32.h>
#else
#include <gdk/gdkx.h>
#endif
void
on_drawingarea1_realize (GtkWidget * widget, gpointer user_data)
{

  // Unset Double Buffering on DrawingArea to 
  // eliminate flickering of glview
  GTK_WIDGET_UNSET_FLAGS (widget, GTK_DOUBLE_BUFFERED);
  pGLView = new CGLView ();
  if (pGLView)
    {
      GdkWindow *gdkwin = GTK_WIDGET (widget)->window;
	  
#ifdef WIN32
	  glong hWnd;
      hWnd = (glong) gdk_win32_drawable_get_handle (gdkwin);	// get HWND
	  pGLView->SetWindow ((HWND) hWnd);
#else
	  Display* pDisplay = gdk_x11_drawable_get_xdisplay(gdkwin);
	  Window window = (Window) gdk_x11_drawable_get_xid(gdkwin);
	  pGLView->SetWindow (pDisplay, window);
#endif

     
      pGLView->SetupGLContext (TRUE);
      gint w, h;
      gtk_widget_get_size_request (widget, &w, &h);
      pGLView->Resize (w, h);
    }
}


gboolean
on_drawingarea1_configure_event (GtkWidget * widget,
				 GdkEventConfigure * event,
				 gpointer user_data)
{
  if (pGLView)
    {
      pGLView->Resize (event->width, event->height);
    }
  return FALSE;
}


gboolean
on_drawingarea1_expose_event (GtkWidget * widget,
			      GdkEventExpose * event, gpointer user_data)
{
  if (pGLView)
    {
      pGLView->RenderScene ();
      UpdateDrawingArea (GTK_WIDGET (widget));
    }
  return FALSE;
}

void
on_MainWindow_realize (GtkWidget * widget, gpointer user_data)
{
  gtk_widget_set_size_request (widget, 800, 600);
}