Normalized the spacing around symbols, for the most part. Ho-hum.
[freeglut] / src / freeglut_main.c
index cfda031..360537b 100644 (file)
@@ -29,8 +29,6 @@
 #include "config.h"
 #endif
 
-#define  G_LOG_DOMAIN  "freeglut-main"
-
 #include "../include/GL/freeglut.h"
 #include "freeglut_internal.h"
 
@@ -85,12 +83,28 @@ static void fghRedrawWindowByHandle
 {
     SFG_Window* window = fgWindowByHandle( handle );
     freeglut_return_if_fail( window != NULL );
-    freeglut_return_if_fail( window->Callbacks.Display != NULL );
+
+    /*
+     * XXX Other than clearing the Redisplay flag or not,
+     * XXX we may as well rely on the INVOK_WCB() doing this
+     * XXX pointer-check.
+     * XXX
+     * XXX If we do not invoke the display because the pointer
+     * XXX is not defined (should never happen, really), then
+     * XXX we may enter an infinite busy-loop trying to update
+     * XXX the window.  Similarly, if we skip because the window
+     * XXX is not visible.  However, if the window becomes visible
+     * XXX at a later time, the window should get its callback
+     * XXX invoked.  I would recommend removing the first check,
+     * XXX and making the second check only affect whether the
+     * XXX callback is invoked---but always clear the flag, if
+     * XXX the {window} pointer is defined.
+     */
+    freeglut_return_if_fail( FETCH_WCB( *window, Display ) );
     freeglut_return_if_fail( window->State.Visible == TRUE );
 
-    fgSetWindow( window );
     window->State.Redisplay = FALSE;
-    window->Callbacks.Display();
+    INVOKE_WCB( *window, Display, ( ) );
 }
 
 /*
@@ -105,16 +119,18 @@ static void fghReshapeWindowByHandle
     ( HWND handle, int width, int height )
 #endif
 {
-    SFG_Window *current_window = fgStructure.Window ;
+    SFG_Window *current_window = fgStructure.Window;
 
     SFG_Window* window = fgWindowByHandle( handle );
     freeglut_return_if_fail( window != NULL );
 
-    fgSetWindow( window );
-    if( window->Callbacks.Reshape != NULL )
-        window->Callbacks.Reshape( width, height );
-    else
+    if( !( FETCH_WCB( *window, Reshape ) ) )
+    {
+        fgSetWindow( window );
         glViewport( 0, 0, width, height );
+    }
+    else
+        INVOKE_WCB( *window, Reshape, ( width, height ) );
 
     /*
      * Force a window redraw.  In Windows at least this is only a partial
@@ -123,10 +139,10 @@ static void fghReshapeWindowByHandle
      * But without this we get this bad behaviour whenever we resize the
      * window.
      */
-    window->State.Redisplay = TRUE ;
+    window->State.Redisplay = TRUE;
 
-    if ( window->IsMenu )
-        fgSetWindow ( current_window ) ;
+    if( window->IsMenu )
+        fgSetWindow( current_window );
 }
 
 /*
@@ -135,23 +151,31 @@ static void fghReshapeWindowByHandle
 static void fghcbDisplayWindow( SFG_Window *window, SFG_Enumerator *enumerator )
 {
 #if TARGET_HOST_UNIX_X11
-    if( (window->Callbacks.Display != NULL) &&
-        (window->State.Redisplay == TRUE) &&
-        (window->State.Visible == TRUE) )
+    /*
+     * XXX Do we need/want to check the callback pointer here?
+     * XXX INVOKE_WCB() will check for us.  Arguably, the
+     * XXX Redisplay status flag should be cleared regardless
+     * XXX of any concern but that {window} is a valid pointer
+     * XXX (which this function is assuming anyway).
+     * XXX Especially since old GLUT wouldn't even enter its main
+     * XXX loop if you didn't have a display callback defined...
+     */
+    if( ( FETCH_WCB( *window, Display ) ) &&
+        ( window->State.Redisplay == TRUE ) &&
+        ( window->State.Visible == TRUE ) )
     {
-        SFG_Window *current_window = fgStructure.Window ;
+        SFG_Window *current_window = fgStructure.Window;
 
-        fgSetWindow( window );
         window->State.Redisplay = FALSE;
-        window->Callbacks.Display();
-        fgSetWindow( current_window ) ;
+        INVOKE_WCB( *window, Display, ( ) );
+        fgSetWindow( current_window );
     }
 
 #elif TARGET_HOST_WIN32
 
     if( window->State.NeedToResize )
     {
-        SFG_Window *current_window = fgStructure.Window ;
+        SFG_Window *current_window = fgStructure.Window;
 
         fgSetWindow( window );
 
@@ -162,18 +186,21 @@ static void fghcbDisplayWindow( SFG_Window *window, SFG_Enumerator *enumerator )
         );
 
         window->State.NeedToResize = FALSE;
-        fgSetWindow ( current_window ) ;
+        fgSetWindow ( current_window );
     }
 
-    if( (window->Callbacks.Display != NULL) &&
-        (window->State.Redisplay == TRUE) &&
-        (window->State.Visible == TRUE) )
+    /*
+     * XXX See above comment about the Redisplay flag...
+     */
+    if( ( FETCH_WCB( *window, Display ) ) &&
+        ( window->State.Redisplay == TRUE ) &&
+        ( window->State.Visible == TRUE ) )
     {
-      window->State.Redisplay = FALSE;
+        window->State.Redisplay = FALSE;
 
-      RedrawWindow( 
-        window->Window.Handle, NULL, NULL, 
-        RDW_NOERASE | RDW_INTERNALPAINT | RDW_INVALIDATE | RDW_UPDATENOW
+        RedrawWindow(
+            window->Window.Handle, NULL, NULL, 
+            RDW_NOERASE | RDW_INTERNALPAINT | RDW_INVALIDATE | RDW_UPDATENOW
         );
     }
 
@@ -201,7 +228,7 @@ static void fghDisplayAll( void )
 static void fghcbCheckJoystickPolls( SFG_Window *window,
                                      SFG_Enumerator *enumerator )
 {
-    long int checkTime = fgElapsedTime();
+    long int checkTime = fgElapsedTime( );
 
     if( window->State.JoystickLastPoll + window->State.JoystickPollRate <=
         checkTime )
@@ -231,7 +258,7 @@ static void fghCheckJoystickPolls( void )
  */
 static void fghCheckTimers( void )
 {
-    long checkTime = fgElapsedTime();
+    long checkTime = fgElapsedTime( );
     SFG_Timer *timer, *next;
     SFG_List timedOut;
 
@@ -269,19 +296,31 @@ static void fghCheckTimers( void )
  */
 long fgElapsedTime( void )
 {
+    if (fgState.Time.Set)
+    {
 #if TARGET_HOST_UNIX_X11
-    struct timeval now;
-    long elapsed;
+        struct timeval now;
+        long elapsed;
     
-    gettimeofday( &now, NULL );
+        gettimeofday( &now, NULL );
     
-    elapsed = (now.tv_usec - fgState.Time.Value.tv_usec) / 1000;
-    elapsed += (now.tv_sec - fgState.Time.Value.tv_sec) * 1000;
+       elapsed  = ( now.tv_usec - fgState.Time.Value.tv_usec ) / 1000;
+       elapsed += ( now.tv_sec  - fgState.Time.Value.tv_sec  ) * 1000;
     
-    return( elapsed );
+        return elapsed;
+#elif TARGET_HOST_WIN32
+       return timeGetTime( ) - fgState.Time.Value;
+#endif
+    }
+    else
+    {
+#if TARGET_HOST_UNIX_X11
+        gettimeofday( &fgState.Time.Value, NULL );
 #elif TARGET_HOST_WIN32
-    return (timeGetTime() - fgState.Time.Value);
+        fgState.Time.Value = timeGetTime( );
 #endif
+        fgState.Time.Set = TRUE;
+    }
 }
 
 /*
@@ -293,14 +332,17 @@ void fgError( const char *fmt, ... )
 
     va_start( ap, fmt );
 
-    fprintf( stderr, "freeglut ");
+    fprintf( stderr, "freeglut " );
     if( fgState.ProgramName )
-        fprintf (stderr, "(%s): ", fgState.ProgramName);
+        fprintf( stderr, "(%s): ", fgState.ProgramName );
     vfprintf( stderr, fmt, ap );
     fprintf( stderr, "\n" );
 
     va_end( ap );
 
+    if ( fgState.Initalized )
+        fgDeinitialize( );
+
     exit( 1 );
 }
 
@@ -310,7 +352,7 @@ void fgWarning( const char *fmt, ... )
 
     va_start( ap, fmt );
 
-    fprintf( stderr, "freeglut ");
+    fprintf( stderr, "freeglut " );
     if( fgState.ProgramName )
         fprintf( stderr, "(%s): ", fgState.ProgramName );
     vfprintf( stderr, fmt, ap );
@@ -339,9 +381,9 @@ void fgWarning( const char *fmt, ... )
  * an opaque wall.
  *
  */
-static void fgCheckJoystickCallback( SFG_Window* w, SFG_Enumerator* e)
+static void fgCheckJoystickCallback( SFG_Window* w, SFG_Enumerator* e )
 {
-    if( w->Callbacks.Joystick )
+    if( FETCH_WCB( *w, Joystick ) )
     {
         e->found = TRUE;
         e->data = w;
@@ -356,7 +398,7 @@ static int fgHaveJoystick( void )
     fgEnumWindows( fgCheckJoystickCallback, &enumerator );
     return !!enumerator.data;
 }
-static void fgHavePendingRedisplaysCallback( SFG_Window* w, SFG_Enumerator* e)
+static void fgHavePendingRedisplaysCallback( SFG_Window* w, SFG_Enumerator* e )
 {
     if( w->State.Redisplay )
     {
@@ -365,7 +407,7 @@ static void fgHavePendingRedisplaysCallback( SFG_Window* w, SFG_Enumerator* e)
     }
     fgEnumSubWindows( w, fgHavePendingRedisplaysCallback, e );
 }        
-static int fgHavePendingRedisplays (void)
+static int fgHavePendingRedisplays( void )
 {
     SFG_Enumerator enumerator;
     enumerator.found = FALSE;
@@ -385,14 +427,14 @@ static int fgHaveTimers( void )
  */
 static long fgNextTimer( void )
 {
-    long now = fgElapsedTime();
+    long now = fgElapsedTime( );
     long ret = INT_MAX;
     SFG_Timer *timer;
 
-    for( timer = (SFG_Timer *)fgState.Timers.First;
+    for( timer = ( SFG_Timer * )fgState.Timers.First;
          timer;
-         timer = (SFG_Timer *)timer->Node.Next )
-        ret = MIN( ret, MAX( 0, (timer->TriggerTime) - now ) );
+         timer = ( SFG_Timer * )timer->Node.Next )
+        ret = MIN( ret, MAX( 0, timer->TriggerTime - now ) );
 
     return ret;
 }
@@ -409,28 +451,47 @@ static void fgSleepForEvents( void )
     struct timeval wait;
     long msec;    
     
-    if( fgState.IdleCallback ||
-        fgHavePendingRedisplays() )
+    if( fgState.IdleCallback || fgHavePendingRedisplays( ) )
         return;
     socket = ConnectionNumber( fgDisplay.Display );
     FD_ZERO( &fdset );
     FD_SET( socket, &fdset );
     
-    msec = fgNextTimer();
-    if( fgHaveJoystick() )
+    msec = fgNextTimer( );
+    if( fgHaveJoystick( ) )
         msec = MIN( msec, 10 );
     
-    wait.tv_sec = msec / 1000;
-    wait.tv_usec = (msec % 1000) * 1000;
+    wait.tv_sec  =   msec / 1000;
+    wait.tv_usec = ( msec % 1000 ) * 1000;
     err = select( socket+1, &fdset, NULL, NULL, &wait );
 
     if( -1 == err )
-        printf( "freeglut select() error: %d\n", errno );
+        fgWarning( "freeglut select() error: %d\n", errno );
     
 #elif TARGET_HOST_WIN32
 #endif
 }
 
+#if TARGET_HOST_UNIX_X11
+/*
+ * Returns GLUT modifier mask for an XEvent.
+ */
+int fgGetXModifiers( XEvent *event )
+{
+    int ret = 0;
+
+    if( event->xkey.state & ( ShiftMask | LockMask ) )
+        ret |= GLUT_ACTIVE_SHIFT;
+    if( event->xkey.state & ControlMask )
+        ret |= GLUT_ACTIVE_CTRL;
+    if( event->xkey.state & Mod1Mask )
+        ret |= GLUT_ACTIVE_ALT;
+    
+    return ret;
+}
+#endif
+
+
 /* -- INTERFACE FUNCTIONS -------------------------------------------------- */
 
 /*
@@ -441,7 +502,6 @@ void FGAPIENTRY glutMainLoopEvent( void )
 #if TARGET_HOST_UNIX_X11
     SFG_Window* window;
     XEvent event;
-    int modifiers;
 
     /*
      * This code was repeated constantly, so here it goes into a definition:
@@ -463,14 +523,6 @@ void FGAPIENTRY glutMainLoopEvent( void )
 
         switch( event.type )
         {
-        case DestroyNotify:
-            /*
-             * This is sent to confirm the XDestroyWindow call.
-             * XXX WHY is this commented out?  Should we re-enable it?
-             */
-            /* fgAddToWindowDestroyList ( window, FALSE ); */
-            break;
-
         case ClientMessage:
             /*
              * Destroy the window when the WM_DELETE_WINDOW message arrives
@@ -479,31 +531,11 @@ void FGAPIENTRY glutMainLoopEvent( void )
             {
                 GETWINDOW( xclient ); 
 
-                fgCloseWindow ( window ) ;
+                fgCloseWindow ( window );
                 fgAddToWindowDestroyList ( window, FALSE );
             }
             break;
 
-        case MapNotify:
-        case UnmapNotify:
-            /*
-             * If we never do anything with this, can we just not ask to
-             * get these messages?
-             */
-            break;
-
-        case Expose:
-            /*
-             * We are too dumb to process partial exposes...
-             * XXX Well, we could do it.  However, it seems to only
-             * XXX be potentially useful for single-buffered (since
-             * XXX double-buffered does not respect viewport when we
-             * XXX do a buffer-swap).
-             */
-            if( event.xexpose.count == 0 )
-                fghRedrawWindowByHandle( event.xexpose.window );
-            break;
-
             /*
              * CreateNotify causes a configure-event so that sub-windows are
              * handled compatibly with GLUT.  Otherwise, your sub-windows
@@ -526,6 +558,34 @@ void FGAPIENTRY glutMainLoopEvent( void )
             );
             break;
 
+        case DestroyNotify:
+            /*
+             * This is sent to confirm the XDestroyWindow call.
+             * XXX WHY is this commented out?  Should we re-enable it?
+             */
+            /* fgAddToWindowDestroyList ( window, FALSE ); */
+            break;
+
+        case Expose:
+            /*
+             * We are too dumb to process partial exposes...
+             * XXX Well, we could do it.  However, it seems to only
+             * XXX be potentially useful for single-buffered (since
+             * XXX double-buffered does not respect viewport when we
+             * XXX do a buffer-swap).
+             */
+            if( event.xexpose.count == 0 )
+                fghRedrawWindowByHandle( event.xexpose.window );
+            break;
+
+        case MapNotify:
+        case UnmapNotify:
+            /*
+             * If we never do anything with this, can we just not ask to
+             * get these messages?
+             */
+            break;
+
         case MappingNotify:
             /*
              * Have the client's keyboard knowledge updated (xlib.ps,
@@ -537,7 +597,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
         case VisibilityNotify:
         {
             GETWINDOW( xvisibility ); 
-            if( window->Callbacks.WindowStatus == NULL )
+            if( ! FETCH_WCB( *window, WindowStatus ) )
                 break;
             fgSetWindow( window );
 
@@ -550,17 +610,18 @@ void FGAPIENTRY glutMainLoopEvent( void )
             switch( event.xvisibility.state )
             {
             case VisibilityUnobscured:
-                window->Callbacks.WindowStatus( GLUT_FULLY_RETAINED );
+                INVOKE_WCB( *window, WindowStatus, ( GLUT_FULLY_RETAINED ) );
                 window->State.Visible = TRUE;
                 break;
                 
             case VisibilityPartiallyObscured:
-                window->Callbacks.WindowStatus( GLUT_PARTIALLY_RETAINED );
+                INVOKE_WCB( *window, WindowStatus,
+                            ( GLUT_PARTIALLY_RETAINED ) );
                 window->State.Visible = TRUE;
                 break;
                 
             case VisibilityFullyObscured:
-                window->Callbacks.WindowStatus( GLUT_FULLY_COVERED );
+                INVOKE_WCB( *window, WindowStatus, ( GLUT_FULLY_COVERED ) );
                 window->State.Visible = FALSE;
                 break;
 
@@ -573,28 +634,13 @@ void FGAPIENTRY glutMainLoopEvent( void )
         break;
 
         case EnterNotify:
-        {
-            GETWINDOW( xcrossing );
-            GETMOUSE( xcrossing );
-            if( window->Callbacks.Entry )
-            {
-                fgSetWindow( window ) ;
-                window->Callbacks.Entry( GLUT_ENTERED );
-            }
-        }
-        break;
-
         case LeaveNotify:
-        {
             GETWINDOW( xcrossing );
             GETMOUSE( xcrossing );
-            if( window->Callbacks.Entry )
-            {
-                fgSetWindow( window ) ;
-                window->Callbacks.Entry( GLUT_LEFT );
-            }
-        }
-        break;
+            INVOKE_WCB( *window, Entry, ( ( EnterNotify == event.type ) ?
+                                          GLUT_ENTERED :
+                                          GLUT_LEFT ) );
+            break;
 
         case MotionNotify:
         {
@@ -610,8 +656,8 @@ void FGAPIENTRY glutMainLoopEvent( void )
                     window->ActiveMenu->Window->State.MouseY =
                         event.xmotion.y_root - window->ActiveMenu->Y;
                 }
-                window->ActiveMenu->Window->State.Redisplay = TRUE ;
-                fgSetWindow( window->ActiveMenu->ParentWindow ) ;
+                window->ActiveMenu->Window->State.Redisplay = TRUE;
+                fgSetWindow( window->ActiveMenu->ParentWindow );
 
                 break;
             }
@@ -620,28 +666,14 @@ void FGAPIENTRY glutMainLoopEvent( void )
              * XXX For more than 5 buttons, just check {event.xmotion.state},
              * XXX rather than a host of bit-masks?
              */
-            if( (event.xmotion.state & Button1Mask) ||
-                (event.xmotion.state & Button2Mask) ||
-                (event.xmotion.state & Button3Mask) ||
-                (event.xmotion.state & Button4Mask) ||
-                (event.xmotion.state & Button5Mask) )
-            {
-                /*
-                 * A mouse button was pressed during the movement...
-                 * Is there a motion callback hooked to the window?
-                 */
-                if( window->Callbacks.Motion )
-                {
-                    fgSetWindow ( window ) ;
-                    window->Callbacks.Motion( event.xmotion.x,
-                                              event.xmotion.y );
-                }
-            }
-            else if( window->Callbacks.Passive )
-            {
-                fgSetWindow ( window ) ;
-                window->Callbacks.Passive( event.xmotion.x, event.xmotion.y );
-            }
+#define BUTTON_MASK \
+  ( Button1Mask | Button2Mask | Button3Mask | Button4Mask | Button5Mask )
+            if( event.xmotion.state & BUTTON_MASK )
+                INVOKE_WCB( *window, Motion, ( event.xmotion.x,
+                                               event.xmotion.y ) );
+            else
+                INVOKE_WCB( *window, Passive, ( event.xmotion.x,
+                                                event.xmotion.y ) );
         }
         break;
 
@@ -652,7 +684,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
             int button;
 
             if( event.type == ButtonRelease )
-                pressed = FALSE ;
+                pressed = FALSE;
 
             /*
              * A mouse button has been pressed or released. Traditionally,
@@ -671,6 +703,10 @@ void FGAPIENTRY glutMainLoopEvent( void )
             button = event.xbutton.button - 1;
 
             /*
+             * XXX This comment is replicated in the WIN32 section and
+             * XXX maybe also in the menu code.  Can we move the info
+             * XXX to one central place and *reference* it from here?
+             *
              * Do not execute the application's mouse callback if a menu
              * is hooked to this button.  In that case an appropriate
              * private call should be generated.
@@ -739,7 +775,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
              * No active menu, let's check whether we need to activate one.
              */
             if( ( 0 <= button ) &&
-                ( 2 >= button ) &&
+                ( FREEGLUT_MAX_MENUS > button ) &&
                 ( window->Menu[ button ] ) &&
                 pressed )
             {
@@ -753,87 +789,78 @@ void FGAPIENTRY glutMainLoopEvent( void )
              * Check if there is a mouse or mouse wheel callback hooked to the
              * window
              */
-            if( ( window->Callbacks.Mouse == NULL ) &&
-                ( window->Callbacks.MouseWheel == NULL ) )
+            if( ! FETCH_WCB( *window, Mouse ) &&
+                ! FETCH_WCB( *window, MouseWheel ) )
                 break;
 
-            fgSetWindow( window );
-
-            modifiers = 0;
-            if( event.xbutton.state & ( ShiftMask | LockMask ) )
-                modifiers |= GLUT_ACTIVE_SHIFT;
-            if( event.xbutton.state & ControlMask )
-                modifiers |= GLUT_ACTIVE_CTRL;
-            if( event.xbutton.state & Mod1Mask )
-                modifiers |= GLUT_ACTIVE_ALT;
-            fgStructure.Window->State.Modifiers = modifiers;
+            /*
+             * XXX Why don't we use {window}?  Other code here does...
+             */
+            fgStructure.Window->State.Modifiers = fgGetXModifiers( &event );
 
             /*
              * Finally execute the mouse or mouse wheel callback
              *
              * XXX Use a symbolic constant, *not* "4"!
              */
-            if( ( button < 4 ) || ( !( window->Callbacks.MouseWheel ) ) )
-            {
-                if( window->Callbacks.Mouse )
-                    fgStructure.Window->Callbacks.Mouse(
-                        button,
-                        event.type == ButtonPress ? GLUT_DOWN : GLUT_UP,
-                        event.xbutton.x,
-                        event.xbutton.y
-                    );
-            }
+            if( ( button < 3 ) || ( ! FETCH_WCB( *window, MouseWheel ) ) )
+                INVOKE_WCB( *window, Mouse, ( button,
+                                              pressed ? GLUT_DOWN : GLUT_UP,
+                                              event.xbutton.x,
+                                              event.xbutton.y )
+                );
             else
             {
-                if( ( button >= 4 ) && window->Callbacks.MouseWheel )
-                {
-                    /*
-                     * Map 4 and 5 to wheel zero; EVEN to +1, ODD to -1
-                     *  "  6 and 7 "    "   one; ...
-                     *
-                     * XXX This *should* be behind some variables/macros,
-                     * XXX since the order and numbering isn't certain
-                     * XXX See XFree86 configuration docs (even back in the
-                     * XXX 3.x days, and especially with 4.x).
-                     */
-                    int wheel_number = (button - 4) / 2;
-                    int direction = (button & 1)*2 - 1;
-
-                    if( ButtonPress )
-                        fgStructure.Window->Callbacks.MouseWheel(
-                            wheel_number,
-                            direction,
-                            event.xbutton.x,
-                            event.xbutton.y
-                        );
-                }
+                /*
+                 * Map 4 and 5 to wheel zero; EVEN to +1, ODD to -1
+                 *  "  6 and 7 "    "   one; ...
+                 *
+                 * XXX This *should* be behind some variables/macros,
+                 * XXX since the order and numbering isn't certain
+                 * XXX See XFree86 configuration docs (even back in the
+                 * XXX 3.x days, and especially with 4.x).
+                 *
+                 * XXX Note that {button} has already been decremeted
+                 * XXX in mapping from X button numbering to GLUT.
+                 */
+                int wheel_number = ( button - 3 ) / 2;
+                int direction = -1;
+                if( button % 2 )
+                    direction = 1;
+                
+                if( pressed )
+                    INVOKE_WCB( *window, MouseWheel, ( wheel_number,
+                                                       direction,
+                                                       event.xbutton.x,
+                                                       event.xbutton.y )
+                    );
             }
 
             /*
              * Trash the modifiers state
              */
             fgStructure.Window->State.Modifiers = 0xffffffff;
-            break;
         }
+        break;
 
         case KeyRelease:
         case KeyPress:
         {
-            FGCBkeyboard keyboard_cb;
-            FGCBspecial special_cb;
+            FGCBKeyboard keyboard_cb;
+            FGCBSpecial special_cb;
 
             GETWINDOW( xkey );
             GETMOUSE( xkey );
 
             if( event.type == KeyPress )
             {
-                keyboard_cb = window->Callbacks.Keyboard;
-                special_cb = window->Callbacks.Special;
+                keyboard_cb = FETCH_WCB( *window, Keyboard );
+                special_cb  = FETCH_WCB( *window, Special  );
             }
             else
             {
-                keyboard_cb = window->Callbacks.KeyboardUp;
-                special_cb = window->Callbacks.SpecialUp;
+                keyboard_cb = FETCH_WCB( *window, KeyboardUp );
+                special_cb  = FETCH_WCB( *window, SpecialUp  );
             }
 
             /*
@@ -850,7 +877,8 @@ void FGAPIENTRY glutMainLoopEvent( void )
                  * Check for the ASCII/KeySym codes associated with the event:
                  */
                 len = XLookupString( &event.xkey, asciiCode, sizeof(asciiCode),
-                                     &keySym, &composeStatus );
+                                     &keySym, &composeStatus
+                );
 
                 /*
                  * GLUT API tells us to have two separate callbacks...
@@ -863,25 +891,10 @@ void FGAPIENTRY glutMainLoopEvent( void )
                     if( keyboard_cb )
                     {
                         fgSetWindow( window );
-
-                        /*
-                         * Remember the current modifiers state
-                         */
-                        modifiers = 0;
-                        if( event.xkey.state & ( ShiftMask | LockMask ) )
-                            modifiers |= GLUT_ACTIVE_SHIFT;
-                        if( event.xkey.state & ControlMask )
-                            modifiers |= GLUT_ACTIVE_CTRL;
-                        if( event.xkey.state & Mod1Mask )
-                            modifiers |= GLUT_ACTIVE_ALT;
-                        window->State.Modifiers = modifiers;
-
+                        window->State.Modifiers = fgGetXModifiers( &event );
                         keyboard_cb( asciiCode[ 0 ],
-                                     event.xkey.x, event.xkey.y );
-
-                        /*
-                         * Trash the modifiers state
-                         */
+                                     event.xkey.x, event.xkey.y
+                        );
                         window->State.Modifiers = 0xffffffff;
                     }
                 }
@@ -929,27 +942,11 @@ void FGAPIENTRY glutMainLoopEvent( void )
                      * Execute the callback (if one has been specified),
                      * given that the special code seems to be valid...
                      */
-                    if( special_cb && (special != -1) )
+                    if( special_cb && ( special != -1 ) )
                     {
                         fgSetWindow( window );
-
-                        /*
-                         * Remember the current modifiers state
-                         */
-                        modifiers = 0;
-                        if( event.xkey.state & ( ShiftMask | LockMask ) )
-                            modifiers |= GLUT_ACTIVE_SHIFT;
-                        if( event.xkey.state & ControlMask )
-                            modifiers |= GLUT_ACTIVE_CTRL;
-                        if( event.xkey.state & Mod1Mask )
-                            modifiers |= GLUT_ACTIVE_ALT;
-                        window->State.Modifiers = modifiers;
-
+                        window->State.Modifiers = fgGetXModifiers( &event );
                         special_cb( special, event.xkey.x, event.xkey.y );
-
-                        /*
-                         * Trash the modifiers state
-                         */
                         window->State.Modifiers = 0xffffffff;
                     }
                 }
@@ -957,8 +954,11 @@ void FGAPIENTRY glutMainLoopEvent( void )
         }
         break;
 
+        case ReparentNotify:
+            break; /* XXX Should disable this event */
+
         default:
-            fgWarning ("Unknown X event type: %d", event.type);
+            fgWarning( "Unknown X event type: %d", event.type );
             break;
         }
     }
@@ -970,7 +970,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
     while( PeekMessage( &stMsg, NULL, 0, 0, PM_NOREMOVE ) )
     {
         if( GetMessage( &stMsg, NULL, 0, 0 ) == 0 )
-            fgState.ExecState = GLUT_EXEC_STATE_STOP ;
+            fgState.ExecState = GLUT_EXEC_STATE_STOP;
 
         TranslateMessage( &stMsg );
         DispatchMessage( &stMsg );
@@ -991,7 +991,7 @@ void FGAPIENTRY glutMainLoopEvent( void )
 void FGAPIENTRY glutMainLoop( void )
 {
 #if TARGET_HOST_WIN32
-    SFG_Window *window = (SFG_Window *)fgStructure.Windows.First ;
+    SFG_Window *window = (SFG_Window *)fgStructure.Windows.First;
 #endif
 
     freeglut_assert_ready;
@@ -1008,20 +1008,19 @@ void FGAPIENTRY glutMainLoop( void )
      */
     while( window )
     {
-        if ( window->Callbacks.Visibility )
+        if( FETCH_WCB( *window, Visibility ) )
         {
-            SFG_Window *current_window = fgStructure.Window ;
+            SFG_Window *current_window = fgStructure.Window;
 
-            fgSetWindow( window );
-            window->Callbacks.Visibility ( window->State.Visible ) ;
+            INVOKE_WCB( *window, Visibility, ( window->State.Visible ) );
             fgSetWindow( current_window );
         }
         
-        window = (SFG_Window *)window->Node.Next ;
+        window = (SFG_Window *)window->Node.Next;
     }
 #endif
 
-    fgState.ExecState = GLUT_EXEC_STATE_RUNNING ;
+    fgState.ExecState = GLUT_EXEC_STATE_RUNNING;
     while( fgState.ExecState == GLUT_EXEC_STATE_RUNNING )
     {
         glutMainLoopEvent( );
@@ -1033,12 +1032,12 @@ void FGAPIENTRY glutMainLoop( void )
             if( fgState.IdleCallback )
                 fgState.IdleCallback( );
 
-            fgSleepForEvents();
+            fgSleepForEvents( );
         }
     }
 
     {
-        fgExecutionState execState = fgState.ActionOnWindowClose;
+        fgExecutionState execState = fgState.ExecState;
         
         /*
          * When this loop terminates, destroy the display, state and structure
@@ -1047,7 +1046,7 @@ void FGAPIENTRY glutMainLoop( void )
         fgDeinitialize( );
 
         if( execState == GLUT_ACTION_EXIT )
-            exit( 0 ) ;
+            exit( 0 );
     }
 }
 
@@ -1056,13 +1055,28 @@ void FGAPIENTRY glutMainLoop( void )
  */
 void FGAPIENTRY glutLeaveMainLoop( void )
 {
-    fgState.ExecState = GLUT_EXEC_STATE_STOP ;
+    fgState.ExecState = GLUT_EXEC_STATE_STOP;
+}
+
+
+#if TARGET_HOST_WIN32
+/*
+ * Determine a GLUT modifer mask based on MS-WINDOWS system info.
+ */
+int fgGetWin32Modifiers (void)
+{
+    return
+        ( ( ( GetKeyState( VK_LSHIFT   ) < 0 ) ||
+            ( GetKeyState( VK_RSHIFT   ) < 0 )) ? GLUT_ACTIVE_SHIFT : 0 ) |
+        ( ( ( GetKeyState( VK_LCONTROL ) < 0 ) ||
+            ( GetKeyState( VK_RCONTROL ) < 0 )) ? GLUT_ACTIVE_CTRL  : 0 ) |
+        ( ( ( GetKeyState( VK_LMENU    ) < 0 ) ||
+            ( GetKeyState( VK_RMENU    ) < 0 )) ? GLUT_ACTIVE_ALT   : 0 );
 }
 
 /*
  * The window procedure for handling Win32 events
  */
-#if TARGET_HOST_WIN32
 LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
                                LPARAM lParam )
 {
@@ -1071,7 +1085,7 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
     LONG lRet = 1;
 
     if ( ( window == NULL ) && ( uMsg != WM_CREATE ) )
-      return( DefWindowProc( hWnd, uMsg, wParam, lParam ) );
+      return DefWindowProc( hWnd, uMsg, wParam, lParam );
 
     /* printf ( "Window %3d message <%04x> %12d %12d\n", window?window->ID:0,
              uMsg, wParam, lParam ); */
@@ -1088,24 +1102,25 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         window->Window.Device = GetDC( hWnd );
         if( fgState.BuildingAMenu )
         {
-          unsigned int current_DisplayMode = fgState.DisplayMode;
-          fgState.DisplayMode = GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH;
-          fgSetupPixelFormat( window, FALSE, PFD_MAIN_PLANE );
-          fgState.DisplayMode = current_DisplayMode;
-
-          if( fgStructure.MenuContext )
-              wglMakeCurrent( window->Window.Device,
-                              fgStructure.MenuContext->Context ) ;
-          else
-          {
-              fgStructure.MenuContext =
-                  (SFG_MenuContext *)malloc( sizeof(SFG_MenuContext) );
-              fgStructure.MenuContext->Context =
-                  wglCreateContext( window->Window.Device );
-          }
-
-          /* window->Window.Context = wglGetCurrentContext () ;   */
-          window->Window.Context = wglCreateContext( window->Window.Device );
+            unsigned int current_DisplayMode = fgState.DisplayMode;
+            fgState.DisplayMode = GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH;
+            fgSetupPixelFormat( window, FALSE, PFD_MAIN_PLANE );
+            fgState.DisplayMode = current_DisplayMode;
+
+            if( fgStructure.MenuContext )
+                wglMakeCurrent( window->Window.Device,
+                                fgStructure.MenuContext->Context
+                );
+            else
+            {
+                fgStructure.MenuContext =
+                    (SFG_MenuContext *)malloc( sizeof(SFG_MenuContext) );
+                fgStructure.MenuContext->Context =
+                    wglCreateContext( window->Window.Device );
+            }
+
+            /* window->Window.Context = wglGetCurrentContext( );   */
+            window->Window.Context = wglCreateContext( window->Window.Device );
         }
         else
         {
@@ -1135,17 +1150,16 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         break;
 #if 0
     case WM_SETFOCUS: 
-        printf("WM_SETFOCUS: %p\n", window );
+        printf( "WM_SETFOCUS: %p\n", window );
         lRet = DefWindowProc( hWnd, uMsg, wParam, lParam );
         break;
 
     case WM_ACTIVATE: 
-        if (LOWORD(wParam) != WA_INACTIVE)
+        if( LOWORD( wParam ) != WA_INACTIVE )
         {
             /* glutSetCursor( fgStructure.Window->State.Cursor ); */
             printf("WM_ACTIVATE: glutSetCursor( %p, %d)\n", window,
                    window->State.Cursor );
-
             glutSetCursor( window->State.Cursor );
         }
 
@@ -1157,37 +1171,50 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         /*
          * Windows seems to need reminding to erase the cursor for NONE.
          */
+
+        /*
+         * XXX Is this #if 0 section anything that we need to worry
+         * XXX about?  Can we delete it?  If it will ever be used,
+         * XXX why not re-use some common code with the glutSetCursor()
+         * XXX function (or perhaps invoke glutSetCursor())?
+         */
 #if 0
-        if ((LOWORD(lParam) == HTCLIENT) &&
-            (fgStructure.Window->State.Cursor == GLUT_CURSOR_NONE))
+        if( ( LOWORD( lParam ) == HTCLIENT ) &&
+            ( fgStructure.Window->State.Cursor == GLUT_CURSOR_NONE ) )
           SetCursor( NULL );
 #else
+
         /* Set the cursor AND change it for this window class. */
-#        define MAP_CURSOR(a,b) case a: SetCursor( LoadCursor( NULL, b ) ); \
+#define MAP_CURSOR(a,b)                     \
+    case a:                                 \
+        SetCursor( LoadCursor( NULL, b ) ); \
         break;
+
         /* Nuke the cursor AND change it for this window class. */
-#        define ZAP_CURSOR(a,b) case a: SetCursor( NULL ); \
+#define ZAP_CURSOR(a,b)     \
+    case a:                 \
+        SetCursor( NULL );  \
         break;
 
         if( LOWORD( lParam ) == HTCLIENT )
-          switch( window->State.Cursor )
-          {
-              MAP_CURSOR( GLUT_CURSOR_RIGHT_ARROW, IDC_ARROW     );
-              MAP_CURSOR( GLUT_CURSOR_LEFT_ARROW,  IDC_ARROW     );
-              MAP_CURSOR( GLUT_CURSOR_INFO,        IDC_HELP      );
-              MAP_CURSOR( GLUT_CURSOR_DESTROY,     IDC_CROSS     );
-              MAP_CURSOR( GLUT_CURSOR_HELP,        IDC_HELP           );
-              MAP_CURSOR( GLUT_CURSOR_CYCLE,       IDC_SIZEALL   );
-              MAP_CURSOR( GLUT_CURSOR_SPRAY,       IDC_CROSS     );
-              MAP_CURSOR( GLUT_CURSOR_WAIT,                 IDC_WAIT      );
-              MAP_CURSOR( GLUT_CURSOR_TEXT,        IDC_UPARROW   );
-              MAP_CURSOR( GLUT_CURSOR_CROSSHAIR,   IDC_CROSS     );
-              /* MAP_CURSOR( GLUT_CURSOR_NONE,        IDC_NO                   ); */
-              ZAP_CURSOR( GLUT_CURSOR_NONE,        NULL           );
-
-          default:
-              MAP_CURSOR( GLUT_CURSOR_UP_DOWN,     IDC_ARROW     );
-          }
+            switch( window->State.Cursor )
+            {
+                MAP_CURSOR( GLUT_CURSOR_RIGHT_ARROW, IDC_ARROW     );
+                MAP_CURSOR( GLUT_CURSOR_LEFT_ARROW,  IDC_ARROW     );
+                MAP_CURSOR( GLUT_CURSOR_INFO,        IDC_HELP      );
+                MAP_CURSOR( GLUT_CURSOR_DESTROY,     IDC_CROSS     );
+                MAP_CURSOR( GLUT_CURSOR_HELP,        IDC_HELP      );
+                MAP_CURSOR( GLUT_CURSOR_CYCLE,       IDC_SIZEALL   );
+                MAP_CURSOR( GLUT_CURSOR_SPRAY,       IDC_CROSS     );
+                MAP_CURSOR( GLUT_CURSOR_WAIT,        IDC_WAIT      );
+                MAP_CURSOR( GLUT_CURSOR_TEXT,        IDC_UPARROW   );
+                MAP_CURSOR( GLUT_CURSOR_CROSSHAIR,   IDC_CROSS     );
+                /* MAP_CURSOR( GLUT_CURSOR_NONE,        IDC_NO         ); */
+                ZAP_CURSOR( GLUT_CURSOR_NONE,        NULL          );
+
+            default:
+                MAP_CURSOR( GLUT_CURSOR_UP_DOWN,     IDC_ARROW     );
+            }
 #endif
         else
             lRet = DefWindowProc( hWnd, uMsg, wParam, lParam );
@@ -1199,6 +1226,8 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         break;
 
     case WM_PAINT:
+        /* Turn on the visibility in case it was turned off somehow */
+        window->State.Visible = GL_TRUE;
         BeginPaint( hWnd, &ps );
         fghRedrawWindowByHandle( hWnd );
         EndPaint( hWnd, &ps );
@@ -1210,8 +1239,8 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
          */
         if( fgStructure.Window == window )
         {
-            int used = FALSE ;
-            SFG_Window *iter ;
+            int used = FALSE;
+            SFG_Window *iter;
 
             wglMakeCurrent( NULL, NULL );
             /*
@@ -1235,7 +1264,7 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
          * Put on a linked list of windows to be removed after all the
          * callbacks have returned
          */
-        fgAddToWindowDestroyList( window, FALSE ) ;
+        fgAddToWindowDestroyList( window, FALSE );
         DestroyWindow( hWnd );
         break;
 
@@ -1243,7 +1272,7 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         /*
          * The window already got destroyed, so don't bother with it.
          */
-        return( 0 );
+        return 0;
 
     case WM_MOUSEMOVE:
     {
@@ -1252,44 +1281,21 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         
         if ( window->ActiveMenu )
         {
-            window->State.Redisplay = TRUE ;
-
-            /*
-             * Since the window is a menu, make the parent window current
-             */
-            fgSetWindow ( window->ActiveMenu->ParentWindow ) ;
-
+            window->State.Redisplay = TRUE;
+            fgSetWindow ( window->ActiveMenu->ParentWindow );
             break;
         }
 
-        window->State.Modifiers = 
-            ( ( ( GetKeyState( VK_LSHIFT   ) < 0 ) ||
-                ( GetKeyState( VK_RSHIFT   ) < 0 )) ? GLUT_ACTIVE_SHIFT : 0 ) |
-            ( ( ( GetKeyState( VK_LCONTROL ) < 0 ) ||
-                ( GetKeyState( VK_RCONTROL ) < 0 )) ? GLUT_ACTIVE_CTRL  : 0 ) |
-            ( ( ( GetKeyState( VK_LMENU    ) < 0 ) ||
-                ( GetKeyState( VK_RMENU    ) < 0 )) ? GLUT_ACTIVE_ALT   : 0 );
+        window->State.Modifiers = fgGetWin32Modifiers( );
 
         if( ( wParam & MK_LBUTTON ) ||
             ( wParam & MK_MBUTTON ) ||
             ( wParam & MK_RBUTTON ) )
-        {
-            if( window->Callbacks.Motion )
-            {
-                fgSetWindow( window );
-                window->Callbacks.Motion( window->State.MouseX,
-                                          window->State.MouseY );
-            }
-        }
+            INVOKE_WCB( *window, Motion, ( window->State.MouseX,
+                                           window->State.MouseY ) );
         else
-        {
-            if( window->Callbacks.Passive )
-            {
-                fgSetWindow( window );
-                window->Callbacks.Passive( window->State.MouseX,
-                                           window->State.MouseY );
-            }
-        }
+            INVOKE_WCB( *window, Passive, ( window->State.MouseX,
+                                            window->State.MouseY ) );
 
         window->State.Modifiers = 0xffffffff;
     }
@@ -1308,6 +1314,15 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         window->State.MouseX = LOWORD( lParam );
         window->State.MouseY = HIWORD( lParam );
 
+        /*
+         * XXX Either these multi-statement lines should be broken
+         * XXX in the form:
+         * XXX     pressed = TRUE;
+         * XXX     button = GLUT_LEFT_BUTTON;
+         * XXX     break;
+         * XXX ...or we should use a macro (much as I dislike freeglut's
+         * XXX preponderance of using macros to "compress" code).
+         */
         switch( uMsg )
         {
         case WM_LBUTTONDOWN:
@@ -1336,6 +1351,9 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
             return DefWindowProc( hWnd, uMsg, lParam, wParam );
 
         /*
+         * XXX This comment is duplicated in two other spots.
+         * XXX Can we centralize it?
+         *
          * Do not execute the application's mouse callback if a
          * menu is hooked to this button.
          * In that case an appropriate private call should be generated.
@@ -1355,8 +1373,13 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         /* Window has an active menu, it absorbs any mouse click */
         if( window->ActiveMenu )
         {
-            /* Inside the menu, invoke the callback and deactivate the menu*/
-            if( fgCheckActiveMenu( window, window->ActiveMenu ) == TRUE )
+            /* Outside the menu, deactivate the menu if it's a downclick */
+            if( fgCheckActiveMenu( window, window->ActiveMenu ) != TRUE )
+            {
+                if( pressed == TRUE )
+                    fgDeactivateMenu( window->ActiveMenu->ParentWindow );
+            }
+            else  /* In menu, invoke the callback and deactivate the menu*/
             {
                 /*
                  * Save the current window and menu and set the current
@@ -1376,11 +1399,6 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
                 fgSetWindow( save_window );
                 fgStructure.Menu = save_menu;
             }
-            else  /* Out of menu, deactivate the menu if it's a downclick */
-            {
-                if( pressed == TRUE )
-                    fgDeactivateMenu( window->ActiveMenu->ParentWindow );
-            }
 
             /*
              * Let's make the window redraw as a result of the mouse
@@ -1392,7 +1410,7 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
             break;
         }
 
-        if ( ( window->Menu[ button ] != NULL ) && ( pressed == TRUE ) )
+        if( ( window->Menu[ button ] ) && ( pressed == TRUE ) )
         {
             window->State.Redisplay = TRUE;
             fgSetWindow( window );
@@ -1401,24 +1419,19 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
             break;
         }
 
-        if( window->Callbacks.Mouse == NULL )
+        if( ! FETCH_WCB( *window, Mouse ) )
             break;
 
         fgSetWindow( window );
-
-        fgStructure.Window->State.Modifiers = 
-            ( ( ( GetKeyState( VK_LSHIFT   ) < 0 ) ||
-                ( GetKeyState( VK_RSHIFT   ) < 0 )) ? GLUT_ACTIVE_SHIFT : 0 ) |
-            ( ( ( GetKeyState( VK_LCONTROL ) < 0 ) ||
-                ( GetKeyState( VK_RCONTROL ) < 0 )) ? GLUT_ACTIVE_CTRL  : 0 ) |
-            ( ( ( GetKeyState( VK_LMENU    ) < 0 ) ||
-                ( GetKeyState( VK_RMENU    ) < 0 )) ? GLUT_ACTIVE_ALT   : 0 );
-
-        window->Callbacks.Mouse(
-            button,
-            pressed == TRUE ? GLUT_DOWN : GLUT_UP,
-            window->State.MouseX,
-            window->State.MouseY
+        fgStructure.Window->State.Modifiers = fgGetWin32Modifiers( );
+
+        INVOKE_WCB(
+            *window, Mouse,
+            ( button,
+              pressed == TRUE ? GLUT_DOWN : GLUT_UP,
+              window->State.MouseX,
+              window->State.MouseY
+            )
         );
 
         fgStructure.Window->State.Modifiers = 0xffffffff;
@@ -1428,10 +1441,12 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
     case 0x020a:
         /* Should be WM_MOUSEWHEEL but my compiler doesn't recognize it */
     {
-        int wheel_number = LOWORD( lParam );
-        /* THIS IS SPECULATIVE -- John Fay, 10/2/03 */
-        int ticks = HIWORD( lParam ) / 120;
-        /* Should be WHEEL_DELTA instead of 120 */
+        /*
+         * XXX THIS IS SPECULATIVE -- John Fay, 10/2/03
+         * XXX Should use WHEEL_DELTA instead of 120
+         */
+        int wheel_number = LOWORD( wParam );
+        short ticks = ( short )HIWORD( wParam ) / 120;
         int direction = 1;
 
         if( ticks < 0 )
@@ -1448,26 +1463,21 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         /*        window->State.MouseY = HIWORD( lParam ); */
         /* change "lParam" to other parameter */
 
-        if( ( window->Callbacks.MouseWheel == NULL ) &&
-            ( window->Callbacks.Mouse == NULL ) )
+        if( ! FETCH_WCB( *window, MouseWheel ) &&
+            ! FETCH_WCB( *window, Mouse ) )
             break;
 
         fgSetWindow( window );
-        fgStructure.Window->State.Modifiers = 
-            ( ( ( GetKeyState( VK_LSHIFT   ) < 0 ) ||
-                ( GetKeyState( VK_RSHIFT   ) < 0 )) ? GLUT_ACTIVE_SHIFT : 0 ) |
-            ( ( ( GetKeyState( VK_LCONTROL ) < 0 ) ||
-                ( GetKeyState( VK_RCONTROL ) < 0 )) ? GLUT_ACTIVE_CTRL  : 0 ) |
-            ( ( ( GetKeyState( VK_LMENU    ) < 0 ) ||
-                ( GetKeyState( VK_RMENU    ) < 0 )) ? GLUT_ACTIVE_ALT   : 0 );
+        fgStructure.Window->State.Modifiers = fgGetWin32Modifiers( );
 
         while( ticks-- )
-            if( window->Callbacks.MouseWheel )
-                window->Callbacks.MouseWheel(
-                    wheel_number,
-                    direction,
-                    window->State.MouseX,
-                    window->State.MouseY
+            if( FETCH_WCB( *window, MouseWheel ) )
+                INVOKE_WCB( *window, MouseWheel,
+                            ( wheel_number,
+                              direction,
+                              window->State.MouseX,
+                              window->State.MouseY
+                            )
                 );
             else  /* No mouse wheel, call the mouse button callback twice */
             {
@@ -1476,24 +1486,27 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
                  * XXX buttons.  Sorry.
                  */
                 int button = wheel_number*2 + 4;
-                button += (1 + direction)/2;
-                window->Callbacks.Mouse( button, GLUT_DOWN,
-                                         window->State.MouseX,
-                                         window->State.MouseY ) ;
-                window->Callbacks.Mouse( button, GLUT_UP,
-                                         window->State.MouseX,
-                                         window->State.MouseY ) ;
+                if( direction > 0 )
+                    ++button;
+                INVOKE_WCB( *window, Mouse,
+                            ( button, GLUT_DOWN,
+                              window->State.MouseX, window->State.MouseY )
+                );
+                INVOKE_WCB( *window, Mouse,
+                            ( button, GLUT_UP,
+                              window->State.MouseX, window->State.MouseX )
+                );
             }
 
         fgStructure.Window->State.Modifiers = 0xffffffff;
     }
-    break ;
+    break;
 
     case WM_SYSKEYDOWN:
     case WM_KEYDOWN:
     {
         int keypress = -1;
-        POINT mouse_pos ;
+        POINT mouse_pos;
 
         if( fgState.IgnoreKeyRepeat && (lParam & KF_REPEAT) )
             break;
@@ -1502,13 +1515,7 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
          * Remember the current modifiers state. This is done here in order 
          * to make sure the VK_DELETE keyboard callback is executed properly.
          */
-        window->State.Modifiers = 
-            ( ( ( GetKeyState( VK_LSHIFT   ) < 0 ) ||
-                ( GetKeyState( VK_RSHIFT   ) < 0 )) ? GLUT_ACTIVE_SHIFT : 0 ) |
-            ( ( ( GetKeyState( VK_LCONTROL ) < 0 ) ||
-                ( GetKeyState( VK_RCONTROL ) < 0 )) ? GLUT_ACTIVE_CTRL  : 0 ) |
-            ( ( ( GetKeyState( VK_LMENU    ) < 0 ) ||
-                ( GetKeyState( VK_RMENU    ) < 0 )) ? GLUT_ACTIVE_ALT   : 0 );
+        window->State.Modifiers = fgGetWin32Modifiers( );
 
         GetCursorPos( &mouse_pos );
         ScreenToClient( window->Window.Handle, &mouse_pos );
@@ -1549,20 +1556,16 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
             /*
              * The delete key should be treated as an ASCII keypress:
              */
-            if( window->Callbacks.Keyboard )
-            {
-                fgSetWindow( window );
-                window->Callbacks.Keyboard( 127, window->State.MouseX,
-                                            window->State.MouseY );
-            }
+            INVOKE_WCB( *window, Keyboard,
+                        ( 127, window->State.MouseX, window->State.MouseY )
+            );
         }
 
-        if( ( keypress != -1 ) && window->Callbacks.Special )
-        {
-            fgSetWindow( window );
-            window->Callbacks.Special( keypress, window->State.MouseX,
-                                       window->State.MouseY );
-        }
+        if( keypress != -1 )
+            INVOKE_WCB( *window, Special,
+                        ( keypress,
+                          window->State.MouseX, window->State.MouseY )
+            );
 
         window->State.Modifiers = 0xffffffff;
     }
@@ -1572,19 +1575,13 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
     case WM_KEYUP:
     {
         int keypress = -1;
-        POINT mouse_pos ;
+        POINT mouse_pos;
 
         /*
          * Remember the current modifiers state. This is done here in order 
          * to make sure the VK_DELETE keyboard callback is executed properly.
          */
-        window->State.Modifiers = 
-            ( ( ( GetKeyState( VK_LSHIFT   ) < 0 ) ||
-                ( GetKeyState( VK_RSHIFT   ) < 0 )) ? GLUT_ACTIVE_SHIFT : 0 ) |
-            ( ( ( GetKeyState( VK_LCONTROL ) < 0 ) ||
-                ( GetKeyState( VK_RCONTROL ) < 0 )) ? GLUT_ACTIVE_CTRL  : 0 ) |
-            ( ( ( GetKeyState( VK_LMENU    ) < 0 ) ||
-                ( GetKeyState( VK_RMENU    ) < 0 )) ? GLUT_ACTIVE_ALT   : 0 );
+        window->State.Modifiers = fgGetWin32Modifiers( );
 
         GetCursorPos( &mouse_pos );
         ScreenToClient( window->Window.Handle, &mouse_pos );
@@ -1625,13 +1622,9 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
               /*
                * The delete key should be treated as an ASCII keypress:
                */
-              if( window->Callbacks.KeyboardUp )
-              {
-                  fgSetWindow( window );
-                  window->Callbacks.KeyboardUp( 127, window->State.MouseX,
-                                                window->State.MouseY );
-              }
-              
+              INVOKE_WCB( *window, KeyboardUp,
+                          ( 127, window->State.MouseX, window->State.MouseY )
+              );
               break;
 
         default:
@@ -1644,22 +1637,18 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
             if( ToAscii( wParam, 0, state, code, 0 ) == 1 )
                 wParam=code[ 0 ];
 
-            if( window->Callbacks.KeyboardUp )
-            {
-                fgSetWindow( window );
-                window->Callbacks.KeyboardUp( (char)wParam,
-                                              window->State.MouseX,
-                                              window->State.MouseY );
-            }
+            INVOKE_WCB( *window, KeyboardUp,
+                        ( (char)wParam,
+                          window->State.MouseX, window->State.MouseY )
+            );
         }
         }
 
-        if( (keypress != -1) && window->Callbacks.SpecialUp )
-        {
-            fgSetWindow( window );
-            window->Callbacks.SpecialUp( keypress, window->State.MouseX,
-                                         window->State.MouseY );
-        }
+        if( keypress != -1 )
+            INVOKE_WCB( *window, SpecialUp,
+                        ( keypress,
+                          window->State.MouseX, window->State.MouseY )
+            );
 
         window->State.Modifiers = 0xffffffff;
     }
@@ -1671,19 +1660,19 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         if( fgState.IgnoreKeyRepeat && (lParam & KF_REPEAT) )
             break;
 
-        if( window->Callbacks.Keyboard )
+        /*
+         * XXX INVOKE_WCB() takes care of the callback-pointer check.
+         * XXX We could just uncoditionally find/trash the Modifiers
+         * XXX and get rid of the "if( ... ) {" and "}".  Unconditinal
+         * XXX code is simpler code.  (^&
+         */
+        if( FETCH_WCB( *window, Keyboard ) )
         {
-            fgSetWindow( window );
-            window->State.Modifiers = 
-                ( ( ( GetKeyState( VK_LSHIFT   ) < 0 ) ||
-                    ( GetKeyState( VK_RSHIFT   ) < 0 )) ? GLUT_ACTIVE_SHIFT : 0 ) |
-                ( ( ( GetKeyState( VK_LCONTROL ) < 0 ) ||
-                    ( GetKeyState( VK_RCONTROL ) < 0 )) ? GLUT_ACTIVE_CTRL  : 0 ) |
-                ( ( ( GetKeyState( VK_LMENU    ) < 0 ) ||
-                    ( GetKeyState( VK_RMENU    ) < 0 )) ? GLUT_ACTIVE_ALT   : 0 );
-
-            window->Callbacks.Keyboard( (char)wParam, window->State.MouseX,
-                                        window->State.MouseY );
+            window->State.Modifiers = fgGetWin32Modifiers( );
+            INVOKE_WCB( *window, Keyboard,
+                        ( (char)wParam,
+                          window->State.MouseX, window->State.MouseY )
+            );
             window->State.Modifiers = 0xffffffff;
         }
     }
@@ -1691,12 +1680,7 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
 
     case WM_CAPTURECHANGED:
         /* User has finished resizing the window, force a redraw */
-        if( window->Callbacks.Display )
-        {
-            fgSetWindow( window );
-
-            window->Callbacks.Display( );
-        }
+        INVOKE_WCB( *window, Display, ( ) );
 
         /*lRet = DefWindowProc( hWnd, uMsg, wParam, lParam ) ; */
         break;
@@ -1740,6 +1724,74 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         /* Pass it on to "DefWindowProc" to repaint a standard border */
         break;
 
+    case WM_SYSCOMMAND :  /* 0x0112 */
+        {
+          /*
+           * We have received a system command message.  Try to act on it.
+           * The commands are passed in through the "lParam" parameter:
+           * Clicking on a corner to resize the window gives a "F004" message
+           * but this is not defined in my header file.
+           */
+            switch ( lParam )
+            {
+            case SC_SIZE:
+                break;
+
+            case SC_MOVE:
+                break;
+
+            case SC_MINIMIZE:
+                /* User has clicked on the "-" to minimize the window */
+                /* Turn off the visibility */
+                window->State.Visible = GL_FALSE;
+                break;
+
+            case SC_MAXIMIZE:
+                break;
+
+            case SC_NEXTWINDOW:
+                break;
+
+            case SC_PREVWINDOW:
+                break;
+
+            case SC_CLOSE:
+                /* Followed very closely by a WM_CLOSE message */
+                break;
+
+            case SC_VSCROLL:
+                break;
+
+            case SC_HSCROLL:
+                break;
+
+            case SC_MOUSEMENU:
+                break;
+
+            case SC_KEYMENU:
+                break;
+
+            case SC_ARRANGE:
+                break;
+
+            case SC_RESTORE:
+                break;
+
+            case SC_TASKLIST:
+                break;
+
+            case SC_SCREENSAVE:
+                break;
+
+            case SC_HOTKEY:
+                break;
+            }
+        }
+
+        /* We need to pass the message on to the operating system as well */
+        lRet = DefWindowProc( hWnd, uMsg, wParam, lParam );
+        break;
+
     default:
         /*
          * Handle unhandled messages
@@ -1748,7 +1800,7 @@ LRESULT CALLBACK fgWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam,
         break;
     }
 
-    return lRet ;
+    return lRet;
 }
 #endif