Halts program execution until a specified event occurs. The event isreturned. All pending events not in the specified mask will be ignored andremoved from the queue.****************************************************************************/void _WDAPI WD_haltEvent(    WD_event *evt,    uint mask){    do {                            /* Wait for an event    */        WD_getEvent(evt,EVT_EVERYEVT);        } while (!(evt->what & mask));}/****************************************************************************PARAMETERS:evt     - Place to store eventmask    - Event mask to useRETURNS:True if an event was pending.REMARKS:Retrieves the next pending event defined in 'mask' from the event queue.The event queue is adjusted to reflect the new state after the event hasbeen removed.****************************************************************************/ibool _WDAPI WD_getEvent(    WD_event *evt,    uint mask){    int     evtID,next,prev;    pumpEvents();    if (moveCursor)        moveCursor(mx,my);                  /* Move the mouse cursor    */    evt->what = EVT_NULLEVT;                /* Default to null event    */    if (count) {        for (evtID = head; evtID != -1; evtID = evtq[evtID].next) {            if (evtq[evtID].what & mask)                break;                      /* Found an event           */            }        if (evtID == -1)            return false;                   /* Event was not found      */        next = evtq[evtID].next;        prev = evtq[evtID].prev;        if (prev != -1)            evtq[prev].next = next;        else            head = next;        if (next != -1)            evtq[next].prev = prev;        else            tail = prev;        *evt = evtq[evtID];                 /* Return the event         */        evtq[evtID].next = freeHead;        /* and return to free list  */        freeHead = evtID;        count--;        if (evt->what == EVT_MOUSEMOVE)            oldMove = -1;        if (evt->what == EVT_KEYREPEAT)            oldKey = -1;        }    return evt->what != EVT_NULLEVT;}/****************************************************************************PARAMETERS:evt     - Place to store eventmask    - Event mask to useRETURNS:True if an event is pending.REMARKS:Peeks at the next pending event defined in 'mask' in the event queue. Theevent is not removed from the event queue.****************************************************************************/ibool _WDAPI WD_peekEvent(    WD_event *evt,    uint mask){    int     evtID;    pumpEvents();    if (moveCursor)        moveCursor(mx,my);                  /* Move the mouse cursor    */    evt->what = EVT_NULLEVT;                /* Default to null event    */    if (count) {        for (evtID = head; evtID != -1; evtID = evtq[evtID].next) {            if (evtq[evtID].what & mask)                break;                      /* Found an event           */            }        if (evtID == -1)            return false;                   /* Event was not found      */        *evt = evtq[evtID];                 /* Return the event         */        }    return evt->what != EVT_NULLEVT;}/****************************************************************************PARAMETERS:hwndMain    - Handle to main window_xRes       - X resolution of graphics mode to be used_yRes       - Y resolulion of graphics mode to be usedRETURNS:Handle to the fullscreen event window if (we return hwndMain on Linux)REMARKS:Initiliase the event handling module. Here we install our mouse handlingISR to be called whenever any button's are pressed or released. We alsobuild the free list of events in the event queue.****************************************************************************/WD_HWND _WDAPI WD_startFullScreen(    WD_HWND hwndMain,    int _xRes,    int _yRes){    int             i;    struct termios  conf;    if (!installed) {        Gpm_Connect gpm;        /* Build free list, and initialise global data structures */        for (i = 0; i < EVENTQSIZE; i++)            evtq[i].next = i+1;        evtq[EVENTQSIZE-1].next = -1;       /* Terminate list           */        count = freeHead = 0;        head = tail = -1;        oldMove = -1;        oldKey = -1;        xRes = _xRes;        yRes = _yRes;        /* Open the console device and initialise it for raw mode */        tty_fd = PM_openConsole();        /* Wait until virtual terminal is active and take over control */        wait_vt_active();        take_vt_control();        /* Initialise keyboard handling to raw mode */        if (ioctl(tty_fd, KDGKBMODE, &oldkbmode)) {            printf("WD_startFullScreen: cannot get keyboard mode.\n");            exit(-1);            }        old_flags = fcntl(tty_fd,F_GETFL);        fcntl(tty_fd,F_SETFL,old_flags |= O_NONBLOCK);        tcgetattr(tty_fd, &conf);        old_conf = conf;        conf.c_lflag &= ~(ICANON | ECHO | ECHOE | ECHOK | ECHONL | NOFLSH | ISIG);        conf.c_iflag &= ~(ISTRIP | IGNCR | ICRNL | INLCR | BRKINT | PARMRK | INPCK | IUCLC | IXON | IXOFF);        conf.c_iflag  |= (IGNBRK | IGNPAR);        conf.c_cc[VMIN] = 1;        conf.c_cc[VTIME] = 0;        conf.c_cc[VSUSP] = 0;        tcsetattr(tty_fd, TCSAFLUSH, &conf);        ioctl(tty_fd, KDSKBMODE, K_MEDIUMRAW);        /* Clear the keyboard state information */        memset(key_down, 0, sizeof(key_down));        ioctl(tty_fd,KDSETLED,key_modifiers = 0);        /* Initialize the mouse connection            The user *MUST* run gpm with the  option -R for this to work (or have a MouseSystems mouse)        */        if(Gpm_Open(&gpm,0) > 0){ /* GPM available */            if ((conn = open(GPM_NODE_FIFO,O_RDONLY|O_SYNC)) < 0)                fprintf(stderr,"WD_startFullScreen: Can't open mouse connection.\n");        }else{            fprintf(stderr,"Warning: when not using gpm -R, only MouseSystems mice are currently supported.\n");            if ((conn = open("/dev/mouse",O_RDONLY|O_SYNC)) < 0)                fprintf(stderr,"WD_startFullScreen: Can't open /dev/mouse.\n");        }        Gpm_Close();        /* TODO: Scale the mouse coordinates to the specific resolution */        /* Save the state of the console */        if ((stateBuf = malloc(PM_getConsoleStateSize())) == NULL) {            printf("Out of memory!\n");            exit(-1);            }        PM_saveConsoleState(stateBuf,tty_fd);        initmode = VBE_getVideoMode();        /* Initialize the signal handler for timer events */        signal(SIGALRM, timerHandler);        /* Capture termination signals so we can clean up properly */        signal(SIGTERM, exitHandler);        signal(SIGINT, exitHandler);        signal(SIGQUIT, exitHandler);        atexit(restore_term);        /* Signal that we are installed */        installed = true;        }    return hwndMain;}/****************************************************************************REMARKS:Lets the library know when fullscreen graphics mode has been initialized sothat we can properly scale the mouse driver coordinates.****************************************************************************/void _WDAPI WD_inFullScreen(void){    /* Nothing to do in here */}/****************************************************************************REMARKS:Suspends all of our event handling operations. This is also used tode-install the event handling code.****************************************************************************/void _WDAPI WD_restoreGDI(void){    restore_term();}/****************************************************************************PARAMETERS:ticks   - Number of ticks between timer tick messagesRETURNS:Previous value for the timer tick event spacing.REMARKS:The event module will automatically generate periodic timer tick events foryou, with 'ticks' between each event posting. If you set the value of'ticks' to 0, the timer tick events are turned off.****************************************************************************/int _WDAPI WD_setTimerTick(    int ticks){    int                 old;    struct itimerval    tim;    long                ms = TICKS_TO_USEC(ticks);    getitimer(ITIMER_REAL, &tim);    old = USEC_TO_TICKS(tim.it_value.tv_sec*1000000.0 + tim.it_value.tv_usec);    tim.it_interval.tv_sec  = ms / 1000000;    tim.it_interval.tv_usec = ms % 1000000;    setitimer(ITIMER_REAL, &tim, NULL);    return old;}/****************************************************************************PARAMETERS:saveState   - Address of suspend app callback to registerREMARKS:Registers a user application supplied suspend application callback so thatwe can properly handle virtual terminal switching.****************************************************************************/void _WDAPI WD_setSuspendAppCallback(    int (_ASMAPI *saveState)(int flags)){  suspendAppCallback = saveState;}/****************************************************************************PARAMETERS:x   - New X coordinate to move the mouse cursor toy   - New Y coordinate to move the mouse cursor toREMARKS:Moves to mouse cursor to the specified coordinate.****************************************************************************/void _WDAPI WD_setMousePos(    int x,    int y){    mx = x;    my = y;}/****************************************************************************PARAMETERS:x   - Place to store X coordinate of mouse cursory   - Place to store Y coordinate of mouse cursorREMARKS:Reads the current mouse cursor location int *screen* coordinates.****************************************************************************/void _WDAPI WD_getMousePos(    int *x,    int *y){    *x = mx;    *y = my;}/****************************************************************************PARAMETERS:mcb - Address of mouse callback functionREMARKS:Registers an application supplied mouse callback function that is calledwhenever the mouse cursor moves.****************************************************************************/void _WDAPI WD_setMouseCallback(    void (_ASMAPI *mcb)(int x,int y)){    moveCursor = mcb;}/****************************************************************************PARAMETERS:xRes    - New X resolution of graphics modeyRes    - New Y resolution of graphics modeREMARKS:This is called to inform the event handling code that the screen resolutionhas changed so that the mouse coordinates can be scaled appropriately.****************************************************************************/void _WDAPI WD_changeResolution(    int xRes,    int yRes){    //  Gpm_FitValues(xRes, yRes);  // ??}/****************************************************************************PARAMETERS:scancode    - Scan code to check if a key is downREMARKS:Determines if a particular key is down based on the scan code for the key.****************************************************************************/ibool _WDAPI WD_isKeyDown(    uchar scancode){       return key_down[scancode];}/****************************************************************************REMARKS:Determines if the application needs to run in safe mode. Not necessary foranything but broken Windows 95 display drivers so we return false forLinux.****************************************************************************/int _WDAPI WD_isSafeMode(void){    return false;}