/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          https://www.mrpt.org/                            |
   |                                                                           |
   | Copyright (c) 2005-2021, Individual contributors, see AUTHORS file        |
   | See: https://www.mrpt.org/Authors - All rights reserved.                  |
   | Released under BSD License. See details in https://www.mrpt.org/License   |
   +---------------------------------------------------------------------------+ */

#include <GL/freeglut.h>
#include "freeglut_internal.h"

#if TARGET_HOST_WINCE
#include <aygshell.h>
#pragma comment( lib, "Aygshell.lib" )

static wchar_t* fghWstrFromStr(const char* str)
{
    int i,len=strlen(str);
    wchar_t* wstr = (wchar_t*)malloc(2*len+2);
    for(i=0; i<len; i++)
        wstr[i] = str[i];
    wstr[len] = 0;
    return wstr;
}


#endif /* TARGET_HOST_WINCE */

/*
 * TODO BEFORE THE STABLE RELEASE:
 *
 *  fgChooseVisual()        -- OK, but what about glutInitDisplayString()?
 *  fgSetupPixelFormat      -- ignores the display mode settings
 *  fgOpenWindow()          -- check the Win32 version, -iconic handling!
 *  fgCloseWindow()         -- check the Win32 version
 *  glutCreateWindow()      -- Check when default position and size is {-1,-1}
 *  glutCreateSubWindow()   -- Check when default position and size is {-1,-1}
 *  glutDestroyWindow()     -- check the Win32 version
 *  glutSetWindow()         -- check the Win32 version
 *  glutGetWindow()         -- OK
 *  glutSetWindowTitle()    -- check the Win32 version
 *  glutSetIconTitle()      -- check the Win32 version
 *  glutShowWindow()        -- check the Win32 version
 *  glutHideWindow()        -- check the Win32 version
 *  glutIconifyWindow()     -- check the Win32 version
 *  glutReshapeWindow()     -- check the Win32 version
 *  glutPositionWindow()    -- check the Win32 version
 *  glutPushWindow()        -- check the Win32 version
 *  glutPopWindow()         -- check the Win32 version
 */

/* -- PRIVATE FUNCTIONS ---------------------------------------------------- */

/*
 * Chooses a visual basing on the current display mode settings
 */
#if TARGET_HOST_UNIX_X11

XVisualInfo* fgChooseVisual( void )
{
#define BUFFER_SIZES 6
    int bufferSize[BUFFER_SIZES] = { 16, 12, 8, 4, 2, 1 };
    GLboolean wantIndexedMode = GL_FALSE;
    int attributes[ 32 ];
    int where = 0;

    /* First we have to process the display mode settings... */
/*
 * XXX Why is there a semi-colon in this #define?  The code
 * XXX that uses the macro seems to always add more semicolons...
 */
#define ATTRIB(a) attributes[where++]=a;
#define ATTRIB_VAL(a,v) {ATTRIB(a); ATTRIB(v);}

    if( fgState.DisplayMode & GLUT_INDEX )
    {
        ATTRIB_VAL( GLX_BUFFER_SIZE, 8 );
        wantIndexedMode = GL_TRUE;
    }
    else
    {
        ATTRIB( GLX_RGBA );
        ATTRIB_VAL( GLX_RED_SIZE,   1 );
        ATTRIB_VAL( GLX_GREEN_SIZE, 1 );
        ATTRIB_VAL( GLX_BLUE_SIZE,  1 );
        if( fgState.DisplayMode & GLUT_ALPHA )
            ATTRIB_VAL( GLX_ALPHA_SIZE, 1 );
    }

    if( fgState.DisplayMode & GLUT_DOUBLE )
        ATTRIB( GLX_DOUBLEBUFFER );

    if( fgState.DisplayMode & GLUT_STEREO )
        ATTRIB( GLX_STEREO );

    if( fgState.DisplayMode & GLUT_DEPTH )
        ATTRIB_VAL( GLX_DEPTH_SIZE, 1 );

    if( fgState.DisplayMode & GLUT_STENCIL )
        ATTRIB_VAL( GLX_STENCIL_SIZE, 1 );

    if( fgState.DisplayMode & GLUT_ACCUM )
    {
        ATTRIB_VAL( GLX_ACCUM_RED_SIZE,   1 );
        ATTRIB_VAL( GLX_ACCUM_GREEN_SIZE, 1 );
        ATTRIB_VAL( GLX_ACCUM_BLUE_SIZE,  1 );
        if( fgState.DisplayMode & GLUT_ALPHA )
            ATTRIB_VAL( GLX_ACCUM_ALPHA_SIZE, 1 );
    }

    if( fgState.DisplayMode & GLUT_AUX1 )
        ATTRIB_VAL( GLX_AUX_BUFFERS, 1 );
    if( fgState.DisplayMode & GLUT_AUX2 )
        ATTRIB_VAL( GLX_AUX_BUFFERS, 2 );
    if( fgState.DisplayMode & GLUT_AUX3 )
        ATTRIB_VAL( GLX_AUX_BUFFERS, 3 );
    if( fgState.DisplayMode & GLUT_AUX4 )
        ATTRIB_VAL( GLX_AUX_BUFFERS, 4 );


    /* Push a null at the end of the list */
    ATTRIB( None );

    if( ! wantIndexedMode )
        return glXChooseVisual( fgDisplay.Display, fgDisplay.Screen,
                                attributes );
    else
    {
        XVisualInfo* visualInfo;
        int i;

        /*
         * In indexed mode, we need to check how many bits of depth can we
         * achieve.  We do this by trying each possibility from the list
         * given in the {bufferSize} array.  If we match, we return to caller.
         */
        for( i=0; i<BUFFER_SIZES; i++ )
        {
            attributes[ 1 ] = bufferSize[ i ];
            visualInfo = glXChooseVisual( fgDisplay.Display, fgDisplay.Screen,
                                          attributes );
            if( visualInfo != NULL )
                return visualInfo;
        }
        return NULL;
    }
}
#endif

/*
 * Setup the pixel format for a Win32 window
 */
#if TARGET_HOST_WIN32
GLboolean fgSetupPixelFormat( SFG_Window* window, GLboolean checkOnly,
                              unsigned char layer_type )
{
#if TARGET_HOST_WINCE
    return GL_TRUE;
#else
    PIXELFORMATDESCRIPTOR* ppfd, pfd;
    int flags, pixelformat;

    freeglut_return_val_if_fail( window != NULL, 0 );
    flags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
    if( fgState.DisplayMode & GLUT_DOUBLE )
        flags |= PFD_DOUBLEBUFFER;

#if defined(_MSC_VER)
// MODIFIED FOR MRPT
// JLBC 
//#pragma message( "fgSetupPixelFormat(): there is still some work to do here!" )
#endif

    /* Specify which pixel format do we opt for... */
    pfd.nSize           = sizeof(PIXELFORMATDESCRIPTOR);
    pfd.nVersion        = 1;
    pfd.dwFlags         = flags;
    pfd.iPixelType      = PFD_TYPE_RGBA;
    pfd.cColorBits      = 24;
    pfd.cRedBits        = 0;
    pfd.cRedShift       = 0;
    pfd.cGreenBits      = 0;
    pfd.cGreenShift     = 0;
    pfd.cBlueBits       = 0;
    pfd.cBlueShift      = 0;
    pfd.cAlphaBits      = 0;
    pfd.cAlphaShift     = 0;
    pfd.cAccumBits      = 0;
    pfd.cAccumRedBits   = 0;
    pfd.cAccumGreenBits = 0;
    pfd.cAccumBlueBits  = 0;
    pfd.cAccumAlphaBits = 0;
#if 0
    pfd.cDepthBits      = 32;
    pfd.cStencilBits    = 0;
#else
    pfd.cDepthBits      = 24;
    pfd.cStencilBits    = 8;
#endif
    if( fgState.DisplayMode & GLUT_AUX4 )
        pfd.cAuxBuffers = 4;
    else if( fgState.DisplayMode & GLUT_AUX3 )
        pfd.cAuxBuffers = 3;
    else if( fgState.DisplayMode & GLUT_AUX2 )
        pfd.cAuxBuffers = 2;
    else if( fgState.DisplayMode & GLUT_AUX1 )
        pfd.cAuxBuffers = 1;
    else
        pfd.cAuxBuffers = 0;

    pfd.iLayerType      = layer_type;
    pfd.bReserved       = 0;
    pfd.dwLayerMask     = 0;
    pfd.dwVisibleMask   = 0;
    pfd.dwDamageMask    = 0;

    pfd.cColorBits = (BYTE) GetDeviceCaps( window->Window.Device, BITSPIXEL );
    ppfd = &pfd;

    pixelformat = ChoosePixelFormat( window->Window.Device, ppfd );
    if( pixelformat == 0 )
        return GL_FALSE;

    if( checkOnly )
        return GL_TRUE;
    return SetPixelFormat( window->Window.Device, pixelformat, ppfd );
#endif /* TARGET_HOST_WINCE */
}
#endif

/*
 * Sets the OpenGL context and the fgStructure "Current Window" pointer to
 * the window structure passed in.
 */
void fgSetWindow ( SFG_Window *window )
{
#if TARGET_HOST_UNIX_X11
    if ( window )
        glXMakeCurrent(
            fgDisplay.Display,
            window->Window.Handle,
            window->Window.Context
        );
#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE
    if( fgStructure.CurrentWindow )
        ReleaseDC( fgStructure.CurrentWindow->Window.Handle,
                   fgStructure.CurrentWindow->Window.Device );

    if ( window )
    {
        window->Window.Device = GetDC( window->Window.Handle );
        wglMakeCurrent(
            window->Window.Device,
            window->Window.Context
        );
    }
#endif
    fgStructure.CurrentWindow = window;
}


/*
 * Opens a window. Requires a SFG_Window object created and attached
 * to the freeglut structure. OpenGL context is created here.
 */
void fgOpenWindow( SFG_Window* window, const char* title,
                   int x, int y, int w, int h,
                   GLboolean gameMode, GLboolean isSubWindow )
{
#if TARGET_HOST_UNIX_X11
    XSetWindowAttributes winAttr;
    XTextProperty textProperty;
    XSizeHints sizeHints;
    XWMHints wmHints;
    unsigned long mask;
    unsigned int current_DisplayMode = fgState.DisplayMode ;

    /* Save the display mode if we are creating a menu window */
    if( window->IsMenu && ( ! fgStructure.MenuContext ) )
        fgState.DisplayMode = GLUT_DOUBLE | GLUT_RGB ;

    window->Window.VisualInfo = fgChooseVisual( );

    if( window->IsMenu && ( ! fgStructure.MenuContext ) )
        fgState.DisplayMode = current_DisplayMode ;

    if( ! window->Window.VisualInfo )
    {
        /*
         * The "fgChooseVisual" returned a null meaning that the visual
         * context is not available.
         * Try a couple of variations to see if they will work.
         */
        if( !( fgState.DisplayMode & GLUT_DOUBLE ) )
        {
            fgState.DisplayMode |= GLUT_DOUBLE ;
            window->Window.VisualInfo = fgChooseVisual( );
            fgState.DisplayMode &= ~GLUT_DOUBLE;
        }

        /*
         * GLUT also checks for multi-sampling, but I don't see that
         * anywhere else in FREEGLUT so I won't bother with it for the moment.
         */
    }

    FREEGLUT_INTERNAL_ERROR_EXIT( window->Window.VisualInfo != NULL,
                                  "Visual with necessary capabilities not found", "fgOpenWindow" );

    /*
     * XXX HINT: the masks should be updated when adding/removing callbacks.
     * XXX       This might speed up message processing. Is that true?
     * XXX
     * XXX A: Not appreciably, but it WILL make it easier to debug.
     * XXX    Try tracing old GLUT and try tracing freeglut.  Old GLUT
     * XXX    turns off events that it doesn't need and is a whole lot
     * XXX    more pleasant to trace.  (Think mouse-motion!  Tons of
     * XXX    ``bonus'' GUI events stream in.)
     */
    winAttr.event_mask        =
        StructureNotifyMask | SubstructureNotifyMask | ExposureMask |
        ButtonPressMask | ButtonReleaseMask | KeyPressMask | KeyReleaseMask |
        VisibilityChangeMask | EnterWindowMask | LeaveWindowMask |
        PointerMotionMask | ButtonMotionMask;
    winAttr.background_pixmap = None;
    winAttr.background_pixel  = 0;
    winAttr.border_pixel      = 0;

    winAttr.colormap = XCreateColormap(
        fgDisplay.Display, fgDisplay.RootWindow,
        window->Window.VisualInfo->visual, AllocNone
    );

    mask = CWBackPixmap | CWBorderPixel | CWColormap | CWEventMask;

    if( window->IsMenu || ( gameMode == GL_TRUE ) )
    {
        winAttr.override_redirect = True;
        mask |= CWOverrideRedirect;
    }

    window->Window.Handle = XCreateWindow(
        fgDisplay.Display,
        window->Parent == NULL ? fgDisplay.RootWindow :
        window->Parent->Window.Handle,
        x, y, w, h, 0,
        window->Window.VisualInfo->depth, InputOutput,
        window->Window.VisualInfo->visual, mask,
        &winAttr
    );

    /*
     * The GLX context creation, possibly trying the direct context rendering
     *  or else use the current context if the user has so specified
     */
    if( window->IsMenu )
    {
        /*
         * If there isn't already an OpenGL rendering context for menu
         * windows, make one
         */
        if( !fgStructure.MenuContext )
        {
            fgStructure.MenuContext =
                (SFG_MenuContext *)malloc( sizeof(SFG_MenuContext) );
            fgStructure.MenuContext->VisualInfo = window->Window.VisualInfo;
            fgStructure.MenuContext->Context = glXCreateContext(
                fgDisplay.Display, fgStructure.MenuContext->VisualInfo,
                NULL, ( fgState.DirectContext != GLUT_FORCE_INDIRECT_CONTEXT )
            );
        }

        /* window->Window.Context = fgStructure.MenuContext->Context; */
        window->Window.Context = glXCreateContext(
            fgDisplay.Display, window->Window.VisualInfo,
            NULL, ( fgState.DirectContext != GLUT_FORCE_INDIRECT_CONTEXT )
        );
    }
    else if( fgState.UseCurrentContext )
    {
        window->Window.Context = glXGetCurrentContext( );

        if( ! window->Window.Context )
            window->Window.Context = glXCreateContext(
                fgDisplay.Display, window->Window.VisualInfo,
                NULL, ( fgState.DirectContext != GLUT_FORCE_INDIRECT_CONTEXT )
            );
    }
    else
        window->Window.Context = glXCreateContext(
            fgDisplay.Display, window->Window.VisualInfo,
            NULL, ( fgState.DirectContext != GLUT_FORCE_INDIRECT_CONTEXT )
        );

#if !defined( __FreeBSD__ ) && !defined( __NetBSD__ )
    if(  !glXIsDirect( fgDisplay.Display, window->Window.Context ) )
    {
      if( fgState.DirectContext == GLUT_FORCE_DIRECT_CONTEXT )
        fgError( "Unable to force direct context rendering for window '%s'",
                 title );
      else if( fgState.DirectContext == GLUT_TRY_DIRECT_CONTEXT )
        fgWarning( "Unable to create direct context rendering for window '%s'\nThis may hurt performance.",
                 title );
    }
#endif

    /*
     * XXX Assume the new window is visible by default
     * XXX Is this a  safe assumption?
     */
    window->State.Visible = GL_TRUE;

    sizeHints.flags = 0;
    if ( fgState.Position.Use )
        sizeHints.flags |= USPosition;
    if ( fgState.Size.Use )
        sizeHints.flags |= USSize;

    /*
     * Fill in the size hints values now (the x, y, width and height
     * settings are obsolete, are there any more WMs that support them?)
     * Unless the X servers actually stop supporting these, we should
     * continue to fill them in.  It is *not* our place to tell the user
     * that they should replace a window manager that they like, and which
     * works, just because *we* think that it's not "modern" enough.
     */
    sizeHints.x      = x;
    sizeHints.y      = y;
    sizeHints.width  = w;
    sizeHints.height = h;

    wmHints.flags = StateHint;
    wmHints.initial_state = fgState.ForceIconic ? IconicState : NormalState;
    /* Prepare the window and iconified window names... */
    XStringListToTextProperty( (char **) &title, 1, &textProperty );

    XSetWMProperties(
        fgDisplay.Display,
        window->Window.Handle,
        &textProperty,
        &textProperty,
        0,
        0,
        &sizeHints,
        &wmHints,
        NULL
    );
    XFree( textProperty.value );

    XSetWMProtocols( fgDisplay.Display, window->Window.Handle,
                     &fgDisplay.DeleteWindow, 1 );

    glXMakeCurrent(
        fgDisplay.Display,
        window->Window.Handle,
        window->Window.Context
    );

    XMapWindow( fgDisplay.Display, window->Window.Handle );

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    WNDCLASS wc;
    DWORD flags;
    DWORD exFlags = 0;
    ATOM atom;

    /* Grab the window class we have registered on glutInit(): */
    atom = GetClassInfo( fgDisplay.Instance, _T("FREEGLUT"), &wc );
    FREEGLUT_INTERNAL_ERROR_EXIT ( atom, "Window Class Info Not Found",
                                   "fgOpenWindow" );

    if( gameMode )
    {
        FREEGLUT_INTERNAL_ERROR_EXIT ( window->Parent == NULL,
                                       "Game mode being invoked on a subwindow",
                                       "fgOpenWindow" );

        /*
         * Set the window creation flags appropriately to make the window
         * entirely visible:
         */
        flags = WS_POPUP | WS_CLIPSIBLINGS | WS_CLIPCHILDREN | WS_VISIBLE;
    }
    else
    {
#if !TARGET_HOST_WINCE
        if ( ( ! isSubWindow ) && ( ! window->IsMenu ) )
        {
            /*
             * Update the window dimensions, taking account of window
             * decorations.  "freeglut" is to create the window with the
             * outside of its border at (x,y) and with dimensions (w,h).
             */
            w += (GetSystemMetrics( SM_CXSIZEFRAME ) )*2;
            h += (GetSystemMetrics( SM_CYSIZEFRAME ) )*2 +
                GetSystemMetrics( SM_CYCAPTION );
        }
#endif /* TARGET_HOST_WINCE */

        if( ! fgState.Position.Use )
        {
            x = CW_USEDEFAULT;
            y = CW_USEDEFAULT;
        }
        if( ! fgState.Size.Use )
        {
            w = CW_USEDEFAULT;
            h = CW_USEDEFAULT;
        }

        /*
         * There's a small difference between creating the top, child and
         * game mode windows
         */
        flags = WS_CLIPSIBLINGS | WS_CLIPCHILDREN | WS_VISIBLE;

        if ( window->IsMenu )
        {
            flags |= WS_POPUP;
            exFlags |= WS_EX_TOOLWINDOW;
        }
#if !TARGET_HOST_WINCE
        else if( window->Parent == NULL )
            flags |= WS_OVERLAPPEDWINDOW;
#endif
        else
            flags |= WS_CHILD;
    }

#if TARGET_HOST_WINCE
    {
        wchar_t* wstr = fghWstrFromStr(title);

        window->Window.Handle = CreateWindow(
            _T("FREEGLUT"),
            wstr,
            WS_VISIBLE | WS_POPUP,
            0,0, 240,320,
            NULL,
            NULL,
            fgDisplay.Instance,
            (LPVOID) window
        );

        free(wstr);

        SHFullScreen(window->Window.Handle, SHFS_HIDESTARTICON);
        SHFullScreen(window->Window.Handle, SHFS_HIDESIPBUTTON);
        SHFullScreen(window->Window.Handle, SHFS_HIDETASKBAR);
        MoveWindow(window->Window.Handle, 0, 0, 240, 320, TRUE);
        ShowWindow(window->Window.Handle, SW_SHOW);
        UpdateWindow(window->Window.Handle);
    }
#else
    window->Window.Handle = CreateWindowExA(
        exFlags,
        "FREEGLUT",
        title,
        flags,
        x, y, w, h,
        (HWND) window->Parent == NULL ? NULL : window->Parent->Window.Handle,
        (HMENU) NULL,
        fgDisplay.Instance,
        (LPVOID) window
    );
#endif /* TARGET_HOST_WINCE */

    if( !( window->Window.Handle ) )
        fgError( "Failed to create a window (%s)!", title );

#if TARGET_HOST_WINCE
    ShowWindow( window->Window.Handle, SW_SHOW );
#else
    ShowWindow( window->Window.Handle,
                fgState.ForceIconic ? SW_SHOWMINIMIZED : SW_SHOW );
#endif /* TARGET_HOST_WINCE */

    UpdateWindow( window->Window.Handle );
    ShowCursor( TRUE );  /* XXX Old comments say "hide cursor"! */

#endif

    fgSetWindow( window );

    window->Window.DoubleBuffered =
        ( fgState.DisplayMode & GLUT_DOUBLE ) ? 1 : 0;

    if ( ! window->Window.DoubleBuffered )
    {
        glDrawBuffer ( GL_FRONT );
        glReadBuffer ( GL_FRONT );
    }
}

/*
 * Closes a window, destroying the frame and OpenGL context
 */
void fgCloseWindow( SFG_Window* window )
{
#if TARGET_HOST_UNIX_X11

    glXDestroyContext( fgDisplay.Display, window->Window.Context );
    XDestroyWindow( fgDisplay.Display, window->Window.Handle );
    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    /* Make sure we don't close a window with current context active */
    if( fgStructure.CurrentWindow == window )
        wglMakeCurrent( NULL, NULL );

    /*
     * Step through the list of windows.  If the rendering context
     * is not being used by another window, then we delete it.
     */
    {
        int used = FALSE ;
        SFG_Window *iter ;

        for( iter = (SFG_Window *)fgStructure.Windows.First;
             iter;
             iter = (SFG_Window *)iter->Node.Next )
        {
            if( ( iter->Window.Context == window->Window.Context ) &&
                ( iter != window ) )
                used = TRUE;
        }

        if( ! used )
            wglDeleteContext( window->Window.Context );
    }

    DestroyWindow( window->Window.Handle );
#endif
}


/* -- INTERFACE FUNCTIONS -------------------------------------------------- */

/*
 * Creates a new top-level freeglut window
 */
int FGAPIENTRY glutCreateWindow( const char* title )
{
    /* XXX GLUT does not exit; it simply calls "glutInit" quietly if the
     * XXX application has not already done so.  The "freeglut" community
     * XXX decided not to go this route (freeglut-developer e-mail from
     * XXX Steve Baker, 12/16/04, 4:22 PM CST, "Re: [Freeglut-developer]
     * XXX Desired 'freeglut' behaviour when there is no current window"
     */
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutCreateWindow" );

    return fgCreateWindow( NULL, title, fgState.Position.X, fgState.Position.Y,
                           fgState.Size.X, fgState.Size.Y, GL_FALSE,
                           GL_FALSE )->ID;
}

/*
 * This function creates a sub window.
 */
int FGAPIENTRY glutCreateSubWindow( int parentID, int x, int y, int w, int h )
{
    int ret = 0;
    SFG_Window* window = NULL;
    SFG_Window* parent = NULL;

    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutCreateSubWindow" );
    parent = fgWindowByID( parentID );
    freeglut_return_val_if_fail( parent != NULL, 0 );
    if ( x < 0 )
    {
        x = parent->State.Width + x ;
        if ( w >= 0 ) x -= w ;
    }

    if ( w < 0 ) w = parent->State.Width - x + w ;
    if ( w < 0 )
    {
        x += w ;
        w = -w ;
    }

    if ( y < 0 )
    {
        y = parent->State.Height + y ;
        if ( h >= 0 ) y -= h ;
    }

    if ( h < 0 ) h = parent->State.Height - y + h ;
    if ( h < 0 )
    {
        y += h ;
        h = -h ;
    }

    window = fgCreateWindow( parent, "", x, y, w, h, GL_FALSE, GL_FALSE );
    ret = window->ID;

    return ret;
}

/*
 * Destroys a window and all of its subwindows
 */
void FGAPIENTRY glutDestroyWindow( int windowID )
{
    SFG_Window* window;
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutDestroyWindow" );
    window = fgWindowByID( windowID );
    freeglut_return_if_fail( window != NULL );
    {
        fgExecutionState ExecState = fgState.ExecState;
        fgAddToWindowDestroyList( window );
        fgState.ExecState = ExecState;
    }
}

/*
 * This function selects the current window
 */
void FGAPIENTRY glutSetWindow( int ID )
{
    SFG_Window* window = NULL;

    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSetWindow" );
    if( fgStructure.CurrentWindow != NULL )
        if( fgStructure.CurrentWindow->ID == ID )
            return;

    window = fgWindowByID( ID );
    if( window == NULL )
    {
        fgWarning( "glutSetWindow(): window ID %d not found!", ID );
        return;
    }

    fgSetWindow( window );
}

/*
 * This function returns the ID number of the current window, 0 if none exists
 */
int FGAPIENTRY glutGetWindow( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutGetWindow" );
    if( fgStructure.CurrentWindow == NULL )
        return 0;
    return fgStructure.CurrentWindow->ID;
}

/*
 * This function makes the current window visible
 */
void FGAPIENTRY glutShowWindow( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutShowWindow" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutShowWindow" );

#if TARGET_HOST_UNIX_X11

    XMapWindow( fgDisplay.Display, fgStructure.CurrentWindow->Window.Handle );
    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    ShowWindow( fgStructure.CurrentWindow->Window.Handle, SW_SHOW );

#endif

    fgStructure.CurrentWindow->State.Redisplay = GL_TRUE;
}

/*
 * This function hides the current window
 */
void FGAPIENTRY glutHideWindow( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutHideWindow" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutHideWindow" );

#if TARGET_HOST_UNIX_X11

    if( fgStructure.CurrentWindow->Parent == NULL )
        XWithdrawWindow( fgDisplay.Display,
                         fgStructure.CurrentWindow->Window.Handle,
                         fgDisplay.Screen );
    else
        XUnmapWindow( fgDisplay.Display,
                      fgStructure.CurrentWindow->Window.Handle );
    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    ShowWindow( fgStructure.CurrentWindow->Window.Handle, SW_HIDE );

#endif

    fgStructure.CurrentWindow->State.Redisplay = GL_FALSE;
}

/*
 * Iconify the current window (top-level windows only)
 */
void FGAPIENTRY glutIconifyWindow( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutIconifyWindow" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutIconifyWindow" );

    fgStructure.CurrentWindow->State.Visible   = GL_FALSE;
#if TARGET_HOST_UNIX_X11

    XIconifyWindow( fgDisplay.Display, fgStructure.CurrentWindow->Window.Handle,
                    fgDisplay.Screen );
    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    ShowWindow( fgStructure.CurrentWindow->Window.Handle, SW_MINIMIZE );

#endif

    fgStructure.CurrentWindow->State.Redisplay = GL_FALSE;
}

/*
 * Set the current window's title
 */
void FGAPIENTRY glutSetWindowTitle( const char* title )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSetWindowTitle" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutSetWindowTitle" );
    if( ! fgStructure.CurrentWindow->Parent )
    {
#if TARGET_HOST_UNIX_X11

        XTextProperty text;

        text.value = (unsigned char *) title;
        text.encoding = XA_STRING;
        text.format = 8;
        text.nitems = strlen( title );

        XSetWMName(
            fgDisplay.Display,
            fgStructure.CurrentWindow->Window.Handle,
            &text
        );

        XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */

#elif TARGET_HOST_WIN32

        SetWindowTextA( fgStructure.CurrentWindow->Window.Handle, title );

#elif TARGET_HOST_WINCE
        {
            wchar_t* wstr = fghWstrFromStr(title);

            SetWindowText( fgStructure.CurrentWindow->Window.Handle, wstr );

            free(wstr);
        }
#endif
    }
}

/*
 * Set the current window's iconified title
 */
void FGAPIENTRY glutSetIconTitle( const char* title )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSetIconTitle" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutSetIconTitle" );

    if( ! fgStructure.CurrentWindow->Parent )
    {
#if TARGET_HOST_UNIX_X11

        XTextProperty text;

        text.value = (unsigned char *) title;
        text.encoding = XA_STRING;
        text.format = 8;
        text.nitems = strlen( title );

        XSetWMIconName(
            fgDisplay.Display,
            fgStructure.CurrentWindow->Window.Handle,
            &text
        );

        XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */

#elif TARGET_HOST_WIN32

        SetWindowTextA( fgStructure.CurrentWindow->Window.Handle, title );

#elif TARGET_HOST_WINCE
        {
            wchar_t* wstr = fghWstrFromStr(title);

            SetWindowText( fgStructure.CurrentWindow->Window.Handle, wstr );

            free(wstr);
        }
#endif
    }
}

/*
 * Change the current window's size
 */
void FGAPIENTRY glutReshapeWindow( int width, int height )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutReshapeWindow" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutReshapeWindow" );

    fgStructure.CurrentWindow->State.NeedToResize = GL_TRUE;
    fgStructure.CurrentWindow->State.Width  = width ;
    fgStructure.CurrentWindow->State.Height = height;
}

/*
 * Change the current window's position
 */
void FGAPIENTRY glutPositionWindow( int x, int y )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutPositionWindow" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutPositionWindow" );

#if TARGET_HOST_UNIX_X11

    XMoveWindow( fgDisplay.Display, fgStructure.CurrentWindow->Window.Handle,
                 x, y );
    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    {
        RECT winRect;

        /* "GetWindowRect" returns the pixel coordinates of the outside of the window */
        GetWindowRect( fgStructure.CurrentWindow->Window.Handle, &winRect );
        MoveWindow(
            fgStructure.CurrentWindow->Window.Handle,
            x,
            y,
            winRect.right - winRect.left,
            winRect.bottom - winRect.top,
            TRUE
        );
    }

#endif
}

/*
 * Lowers the current window (by Z order change)
 */
void FGAPIENTRY glutPushWindow( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutPushWindow" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutPushWindow" );

#if TARGET_HOST_UNIX_X11

    XLowerWindow( fgDisplay.Display, fgStructure.CurrentWindow->Window.Handle );

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    SetWindowPos(
        fgStructure.CurrentWindow->Window.Handle,
        HWND_BOTTOM,
        0, 0, 0, 0,
        SWP_NOSIZE | SWP_NOMOVE
    );

#endif
}

/*
 * Raises the current window (by Z order change)
 */
void FGAPIENTRY glutPopWindow( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutPopWindow" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutPopWindow" );

#if TARGET_HOST_UNIX_X11

    XRaiseWindow( fgDisplay.Display, fgStructure.CurrentWindow->Window.Handle );

#elif TARGET_HOST_WIN32 || TARGET_HOST_WINCE

    SetWindowPos(
        fgStructure.CurrentWindow->Window.Handle,
        HWND_TOP,
        0, 0, 0, 0,
        SWP_NOSIZE | SWP_NOMOVE
    );

#endif
}

/*
 * Resize the current window so that it fits the whole screen
 */
void FGAPIENTRY glutFullScreen( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutFullScreen" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutFullScreen" );

    {
#if TARGET_HOST_UNIX_X11
        int x, y;
        Window w;

        XMoveResizeWindow(
            fgDisplay.Display,
            fgStructure.CurrentWindow->Window.Handle,
            0, 0,
            fgDisplay.ScreenWidth,
            fgDisplay.ScreenHeight
        );

        XFlush( fgDisplay.Display ); /* This is needed */

        XTranslateCoordinates(
            fgDisplay.Display,
            fgStructure.CurrentWindow->Window.Handle,
            fgDisplay.RootWindow,
            0, 0, &x, &y, &w
        );

        if (x || y)
        {
            XMoveWindow(
                fgDisplay.Display,
                fgStructure.CurrentWindow->Window.Handle,
                -x, -y
            );
            XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
        }
#elif TARGET_HOST_WIN32
        RECT rect;

        /* For fullscreen mode, force the top-left corner to 0,0
         * and adjust the window rectangle so that the client area
         * covers the whole screen.
         */

        rect.left   = 0;
        rect.top    = 0;
        rect.right  = fgDisplay.ScreenWidth;
        rect.bottom = fgDisplay.ScreenHeight;

        AdjustWindowRect ( &rect, WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS |
                                  WS_CLIPCHILDREN, FALSE );

        /*
         * SWP_NOACTIVATE     Do not activate the window
         * SWP_NOOWNERZORDER  Do not change position in z-order
         * SWP_NOSENDCHANGING Supress WM_WINDOWPOSCHANGING message
         * SWP_NOZORDER       Retains the current Z order (ignore 2nd param)
         */

        SetWindowPos( fgStructure.CurrentWindow->Window.Handle,
                      HWND_TOP,
                      rect.left,
                      rect.top,
                      rect.right  - rect.left,
                      rect.bottom - rect.top,
                      SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOSENDCHANGING |
                      SWP_NOZORDER
                    );
#endif
    }
}

/*
 * A.Donev: Set and retrieve the window's user data
 */
void* FGAPIENTRY glutGetWindowData( void )
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutGetWindowData" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutGetWindowData" );
    return fgStructure.CurrentWindow->UserData;
}

void FGAPIENTRY glutSetWindowData(void* data)
{
    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSetWindowData" );
    FREEGLUT_EXIT_IF_NO_WINDOW ( "glutSetWindowData" );
    fgStructure.CurrentWindow->UserData = data;
}

/*** END OF FILE ***/
