src/msw/display.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        display.cpp
   3 // Purpose:     MSW Implementation of wxDisplay class
   4 // Author:      Royce Mitchell III
   5 // Modified by: VZ (resolutions enumeration/change support, DirectDraw, ...)
   6 // Created:     06/21/02
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) wxWidgets team
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ===========================================================================
  13 // declarations
  14 // ===========================================================================
  15
  16 // ---------------------------------------------------------------------------
  17 // headers
  18 // ---------------------------------------------------------------------------
  19
  20 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  21     #pragma implementation "display.h"
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #ifdef __BORLANDC__
  28     #pragma hdrstop
  29 #endif
  30
  31 #if wxUSE_DISPLAY
  32
  33 #ifndef WX_PRECOMP
  34    #include "wx/app.h"
  35    #include "wx/dynarray.h"
  36    #include "wx/frame.h"
  37 #endif
  38
  39 #include "wx/dynload.h"
  40
  41 #include "wx/display.h"
  42
  43 // the following define is necessary to access the multi-monitor function
  44 // declarations in a manner safe to use w/ Windows 95
  45 #define COMPILE_MULTIMON_STUBS
  46
  47 // if you don't have multimon.h you can download the file from:
  48 //
  49 //  http://www.microsoft.com/msj/0697/monitor/monitortextfigs.htm#fig4
  50 //
  51
  52 #ifdef _MSC_VER
  53     // as (m)any standard header(s), this one doesn't compile without warnings
  54     // with VC++ 6 <sigh>
  55     #pragma warning(disable:4706)
  56 #endif
  57
  58 #include <multimon.h>
  59
  60 #ifdef _MSC_VER
  61     #pragma warning(default:4706)
  62 #endif
  63
  64 #include <ddraw.h>
  65
  66 // we don't want to link with ddraw.lib which contains the real
  67 // IID_IDirectDraw2 definition
  68 const GUID wxIID_IDirectDraw2 =
  69     { 0xB3A6F3E0, 0x2B43, 0x11CF, { 0xA2,0xDE,0x00,0xAA,0x00,0xB9,0x33,0x56 } };
  70
  71 // ----------------------------------------------------------------------------
  72 // macros
  73 // ----------------------------------------------------------------------------
  74
  75 #ifdef _UNICODE
  76     #define WINFUNC(x)  _T(#x) L"W"
  77 #else
  78     #define WINFUNC(x) #x "A"
  79 #endif
  80
  81 // ----------------------------------------------------------------------------
  82 // typedefs for dynamically loaded Windows functions
  83 // ----------------------------------------------------------------------------
  84
  85 typedef LONG (WINAPI *ChangeDisplaySettingsEx_t)(LPCTSTR lpszDeviceName,
  86                                                  LPDEVMODE lpDevMode,
  87                                                  HWND hwnd,
  88                                                  DWORD dwFlags,
  89                                                  LPVOID lParam);
  90
  91 typedef BOOL (PASCAL *DDEnumExCallback_t)(GUID *pGuid,
  92                                           LPTSTR driverDescription,
  93                                           LPTSTR driverName,
  94                                           LPVOID lpContext,
  95                                           HMONITOR hmon);
  96
  97 typedef HRESULT (WINAPI *DirectDrawEnumerateEx_t)(DDEnumExCallback_t lpCallback,
  98                                                   LPVOID lpContext,
  99                                                   DWORD dwFlags);
 100
 101 typedef HRESULT (WINAPI *DirectDrawCreate_t)(GUID *lpGUID,
 102                                              LPDIRECTDRAW *lplpDD,
 103                                              IUnknown *pUnkOuter);
 104
 105 // ----------------------------------------------------------------------------
 106 // private classes
 107 // ----------------------------------------------------------------------------
 108
 109 class wxDisplayInfo
 110 {
 111 public:
 112     // handle of this monitor used by MonitorXXX() functions, never NULL
 113     HMONITOR m_hmon;
 114
 115     // IDirectDraw object used to control this display, may be NULL
 116     IDirectDraw2 *m_pDD2;
 117
 118     // DirectDraw GUID for this display, only valid when using DirectDraw
 119     GUID m_guid;
 120
 121     // the entire area of this monitor in virtual screen coordinates
 122     wxRect m_rect;
 123
 124     // the display device name for this monitor, empty initially and retrieved
 125     // on demand by DoGetName()
 126     wxString m_devName;
 127
 128     wxDisplayInfo() { m_hmon = NULL; m_pDD2 = NULL; }
 129     ~wxDisplayInfo() { if ( m_pDD2 ) m_pDD2->Release(); }
 130 };
 131
 132 WX_DECLARE_OBJARRAY(wxDisplayInfo, wxDisplayInfoArray);
 133 #include "wx/arrimpl.cpp"
 134 WX_DEFINE_OBJARRAY(wxDisplayInfoArray);
 135
 136 // this module is used to cleanup gs_displays array
 137 class wxDisplayModule : public wxModule
 138 {
 139 public:
 140     virtual bool OnInit() { return true; }
 141     virtual void OnExit();
 142
 143     DECLARE_DYNAMIC_CLASS(wxDisplayModule)
 144 };
 145
 146 IMPLEMENT_DYNAMIC_CLASS(wxDisplayModule, wxModule)
 147
 148 // ----------------------------------------------------------------------------
 149 // globals
 150 // ----------------------------------------------------------------------------
 151
 152 // do we use DirectX?
 153 static bool gs_useDirectX = false;
 154
 155 // dynamically resolved DirectDrawCreate()
 156 static DirectDrawCreate_t gs_DirectDrawCreate = NULL;
 157
 158 // this is not really MT-unsafe as wxDisplay is only going to be used from the
 159 // main thread, i.e. we consider that it's a GUI class and so don't protect it
 160 static wxDisplayInfoArray *gs_displays = NULL;
 161
 162 // ===========================================================================
 163 // implementation
 164 // ===========================================================================
 165
 166 // ----------------------------------------------------------------------------
 167 // callbacks for monitor/modes enumeration stuff
 168 // ----------------------------------------------------------------------------
 169
 170 static BOOL CALLBACK wxmswMonitorEnumProc (
 171   HMONITOR hMonitor,        // handle to display monitor
 172   HDC WXUNUSED(hdcMonitor), // handle to monitor-appropriate device context
 173   LPRECT lprcMonitor,       // pointer to monitor intersection rectangle
 174   LPARAM WXUNUSED(dwData)   // data passed from EnumDisplayMonitors (unused)
 175 )
 176 {
 177     wxDisplayInfo *info = new wxDisplayInfo();
 178
 179     // we need hMonitor to be able to map display id to it which is needed for
 180     // MonitorXXX() functions, in particular MonitorFromPoint()
 181     info->m_hmon = hMonitor;
 182
 183     // we also store the display geometry
 184     info->m_rect.SetX ( lprcMonitor->left );
 185     info->m_rect.SetY ( lprcMonitor->top );
 186     info->m_rect.SetWidth ( lprcMonitor->right - lprcMonitor->left );
 187     info->m_rect.SetHeight ( lprcMonitor->bottom - lprcMonitor->top );
 188
 189     // now add this monitor to the array
 190     gs_displays->Add(info);
 191
 192     // continue the enumeration
 193     return true;
 194 }
 195
 196 BOOL PASCAL
 197 wxDDEnumExCallback(GUID *pGuid,
 198                    LPTSTR WXUNUSED(driverDescription),
 199                    LPTSTR driverName,
 200                    LPVOID WXUNUSED(lpContext),
 201                    HMONITOR hmon)
 202 {
 203     if ( pGuid )
 204     {
 205         wxDisplayInfo *info = new wxDisplayInfo();
 206
 207         info->m_hmon = hmon;
 208         info->m_guid = *pGuid;
 209         info->m_devName = driverName;
 210
 211         gs_displays->Add(info);
 212     }
 213     //else: we're called for the primary monitor, skip it
 214
 215     // continue the enumeration
 216     return true;
 217 }
 218
 219 HRESULT WINAPI wxDDEnumModesCallback(LPDDSURFACEDESC lpDDSurfaceDesc,
 220                                      LPVOID lpContext)
 221 {
 222     // we need at least the mode size
 223     static const DWORD FLAGS_REQUIRED = DDSD_HEIGHT | DDSD_WIDTH;
 224     if ( (lpDDSurfaceDesc->dwFlags & FLAGS_REQUIRED) == FLAGS_REQUIRED )
 225     {
 226         wxArrayVideoModes * const modes = (wxArrayVideoModes *)lpContext;
 227
 228         modes->Add(wxVideoMode(lpDDSurfaceDesc->dwWidth,
 229                                lpDDSurfaceDesc->dwHeight,
 230                                lpDDSurfaceDesc->ddpfPixelFormat.dwRGBBitCount,
 231                                lpDDSurfaceDesc->dwRefreshRate));
 232     }
 233
 234     // continue the enumeration
 235     return DDENUMRET_OK;
 236 }
 237
 238 // ----------------------------------------------------------------------------
 239 // local functions
 240 // ----------------------------------------------------------------------------
 241
 242 // initialize gs_displays using DirectX functions
 243 static bool DoInitDirectX()
 244 {
 245     // suppress the errors if ddraw.dll is not found
 246     wxLog::EnableLogging(false);
 247
 248     wxDynamicLibrary dllDX(_T("ddraw.dll"));
 249
 250     wxLog::EnableLogging(true);
 251
 252     if ( !dllDX.IsLoaded() )
 253         return false;
 254
 255     DirectDrawEnumerateEx_t pDDEnumEx = (DirectDrawEnumerateEx_t)
 256         dllDX.GetSymbol(WINFUNC(DirectDrawEnumerateEx));
 257     if ( !pDDEnumEx )
 258         return false;
 259
 260     // we'll also need DirectDrawCreate() later, resolve it right now
 261     gs_DirectDrawCreate = (DirectDrawCreate_t)
 262         dllDX.GetSymbol(_T("DirectDrawCreate"));
 263     if ( !gs_DirectDrawCreate )
 264         return false;
 265
 266     if ( (*pDDEnumEx)(wxDDEnumExCallback,
 267                       NULL,
 268                       DDENUM_ATTACHEDSECONDARYDEVICES) != DD_OK )
 269     {
 270         return false;
 271     }
 272
 273     // ok, it seems like we're going to use DirectDraw and so we're going to
 274     // need ddraw.dll all the time, don't unload it
 275     dllDX.Detach();
 276
 277     return true;
 278 }
 279
 280 // initialize gs_displays using the standard Windows functions
 281 static void DoInitStdWindows()
 282 {
 283     // enumerate all displays
 284     if ( !::EnumDisplayMonitors(NULL, NULL, wxmswMonitorEnumProc, 0) )
 285     {
 286         wxLogLastError(wxT("EnumDisplayMonitors"));
 287
 288         // TODO: still create at least one (valid) entry in gs_displays for the
 289         //       primary display!
 290     }
 291 }
 292
 293 // this function must be called before accessing gs_displays array as it
 294 // creates and initializes it
 295 static void InitDisplays()
 296 {
 297     if ( gs_displays )
 298         return;
 299
 300     gs_displays = new wxDisplayInfoArray();
 301
 302     if ( !gs_useDirectX || !DoInitDirectX() )
 303     {
 304         // either we were told not to try to use DirectX or fall back to std
 305         // functions if DirectX method failed
 306         gs_useDirectX = false;
 307
 308         DoInitStdWindows();
 309     }
 310 }
 311
 312 // convert a DEVMODE to our wxVideoMode
 313 wxVideoMode ConvertToVideoMode(const DEVMODE& dm)
 314 {
 315     // note that dmDisplayFrequency may be 0 or 1 meaning "standard one" and
 316     // although 0 is ok for us we don't want to return modes with 1hz refresh
 317     return wxVideoMode(dm.dmPelsWidth,
 318                        dm.dmPelsHeight,
 319                        dm.dmBitsPerPel,
 320                        dm.dmDisplayFrequency > 1 ? dm.dmDisplayFrequency : 0);
 321 }
 322
 323 // emulation of ChangeDisplaySettingsEx() for Win95
 324 LONG WINAPI ChangeDisplaySettingsExForWin95(LPCTSTR WXUNUSED(lpszDeviceName),
 325                                             LPDEVMODE lpDevMode,
 326                                             HWND WXUNUSED(hwnd),
 327                                             DWORD dwFlags,
 328                                             LPVOID WXUNUSED(lParam))
 329 {
 330     return ::ChangeDisplaySettings(lpDevMode, dwFlags);
 331 }
 332
 333 // ----------------------------------------------------------------------------
 334 // wxDisplayModule
 335 // ----------------------------------------------------------------------------
 336
 337 void wxDisplayModule::OnExit()
 338 {
 339     delete gs_displays;
 340 }
 341
 342 // ---------------------------------------------------------------------------
 343 // wxDisplay
 344 // ---------------------------------------------------------------------------
 345
 346 /* static */
 347 void wxDisplay::UseDirectX(bool useDX)
 348 {
 349     wxCHECK_RET( !gs_displays, _T("it is too late to call UseDirectX") );
 350
 351     gs_useDirectX = useDX;
 352 }
 353
 354 // helper of GetFromPoint() and GetFromWindow()
 355 static int DisplayFromHMONITOR(HMONITOR hmon)
 356 {
 357     if ( hmon )
 358     {
 359         const size_t count = wxDisplay::GetCount();
 360
 361         for ( size_t n = 0; n < count; n++ )
 362         {
 363             if ( hmon == (*gs_displays)[n].m_hmon )
 364                 return n;
 365         }
 366     }
 367
 368     return wxNOT_FOUND;
 369 }
 370
 371 /* static */
 372 size_t wxDisplayBase::GetCount()
 373 {
 374     InitDisplays();
 375
 376     // I'm not sure if they really always return the same thing and if this is
 377     // not true I'd like to know in which situation does it happen
 378     wxASSERT_MSG( gs_displays->GetCount() == (size_t)::GetSystemMetrics(SM_CMONITORS),
 379                     _T("So how many displays does this system have?") );
 380
 381     return gs_displays->GetCount();
 382 }
 383
 384 /* static */
 385 int wxDisplayBase::GetFromPoint ( const wxPoint& pt )
 386 {
 387     POINT pt2;
 388     pt2.x = pt.x;
 389     pt2.y = pt.y;
 390
 391     return DisplayFromHMONITOR(::MonitorFromPoint(pt2, MONITOR_DEFAULTTONULL));
 392 }
 393
 394 /* static */
 395 int wxDisplayBase::GetFromWindow(wxWindow *window)
 396 {
 397     return DisplayFromHMONITOR
 398            (
 399             ::MonitorFromWindow(GetHwndOf(window), MONITOR_DEFAULTTONULL)
 400            );
 401 }
 402
 403 // ----------------------------------------------------------------------------
 404 // wxDisplay ctor/dtor
 405 // ----------------------------------------------------------------------------
 406
 407 wxDisplay::wxDisplay ( size_t n )
 408          : wxDisplayBase ( n )
 409 {
 410     // if we do this in ctor we won't have to call it from all the member
 411     // functions
 412     InitDisplays();
 413
 414     if ( gs_useDirectX )
 415     {
 416         wxDisplayInfo& dpyInfo = (*gs_displays)[n];
 417
 418         LPDIRECTDRAW2& pDD2 = dpyInfo.m_pDD2;
 419         if ( !pDD2 )
 420         {
 421             if ( !gs_DirectDrawCreate )
 422             {
 423                 // what to do??
 424                 return;
 425             }
 426
 427             IDirectDraw *pDD;
 428             HRESULT hr = (*gs_DirectDrawCreate)(&dpyInfo.m_guid, &pDD, NULL);
 429
 430             if ( FAILED(hr) || !pDD )
 431             {
 432                 // what to do??
 433                 wxLogApiError(_T("DirectDrawCreate"), hr);
 434             }
 435             else // got IDirectDraw, we want IDirectDraw2
 436             {
 437                 hr = pDD->QueryInterface(wxIID_IDirectDraw2, (void **)&pDD2);
 438                 if ( FAILED(hr) || !pDD2 )
 439                 {
 440                     wxLogApiError(_T("IDirectDraw::QueryInterface(IDD2)"), hr);
 441                 }
 442
 443                 pDD->Release();
 444             }
 445         }
 446         //else: DirectDraw object corresponding to our display already exists
 447
 448         // increment its ref count to account for Release() in dtor
 449         //
 450         // NB: pDD2 will be only really Release()d when gs_displays is
 451         //     destroyed which is ok as we don't want to recreate DD objects
 452         //     all the time
 453         pDD2->AddRef();
 454     }
 455 }
 456
 457 wxDisplay::~wxDisplay()
 458 {
 459     wxDisplayInfo& dpyInfo = (*gs_displays)[m_index];
 460
 461     LPDIRECTDRAW2& pDD2 = dpyInfo.m_pDD2;
 462     if ( pDD2 )
 463     {
 464         pDD2->Release();
 465     }
 466 }
 467
 468 // ----------------------------------------------------------------------------
 469 // wxDisplay simple accessors
 470 // ----------------------------------------------------------------------------
 471
 472 bool wxDisplay::IsOk() const
 473 {
 474     return m_index < GetCount() &&
 475                 (!gs_useDirectX || (*gs_displays)[m_index].m_pDD2);
 476 }
 477
 478 wxRect wxDisplay::GetGeometry() const
 479 {
 480     wxDisplayInfo& dpyInfo = (*gs_displays)[m_index];
 481     wxRect& rect = dpyInfo.m_rect;
 482     if ( !rect.width )
 483     {
 484         MONITORINFO monInfo;
 485         wxZeroMemory(monInfo);
 486         monInfo.cbSize = sizeof(monInfo);
 487
 488         if ( !::GetMonitorInfo(dpyInfo.m_hmon, &monInfo) )
 489         {
 490             wxLogLastError(_T("GetMonitorInfo"));
 491         }
 492         else
 493         {
 494             wxCopyRECTToRect(monInfo.rcMonitor, rect);
 495         }
 496     }
 497
 498     return rect;
 499 }
 500
 501 wxString wxDisplay::GetName() const
 502 {
 503     wxDisplayInfo& dpyInfo = (*gs_displays)[m_index];
 504     if ( dpyInfo.m_devName.empty() )
 505     {
 506         MONITORINFOEX monInfo;
 507         wxZeroMemory(monInfo);
 508         monInfo.cbSize = sizeof(monInfo);
 509
 510         // NB: Cast from MONITORINFOEX* to MONITORINFO* is done because
 511         //     Mingw headers - unlike the ones from Microsoft's Platform SDK -
 512         //     don't derive the former from the latter in C++ mode and so
 513         //     the pointer's type is not converted implicitly.
 514         if ( !::GetMonitorInfo(dpyInfo.m_hmon, (LPMONITORINFO)&monInfo) )
 515         {
 516             wxLogLastError(_T("GetMonitorInfo"));
 517         }
 518         else
 519         {
 520             dpyInfo.m_devName = monInfo.szDevice;
 521         }
 522     }
 523
 524     return dpyInfo.m_devName;
 525 }
 526
 527 wxString wxDisplay::GetNameForEnumSettings() const
 528 {
 529     int major, minor;
 530     const bool isWin95 = wxGetOsVersion(&major, &minor) == wxWIN95 &&
 531                             major == 4 && minor == 0;
 532
 533     // the first parameter of EnumDisplaySettings() must be NULL under Win95
 534     // according to MSDN but GetMonitorInfo() stub in multimon.h still returns
 535     // something even in this case, so we have to correct this manually
 536     wxString name;
 537     if ( !isWin95 )
 538         name = GetName();
 539
 540     return name;
 541 }
 542
 543 // ----------------------------------------------------------------------------
 544 // video modes enumeration
 545 // ----------------------------------------------------------------------------
 546
 547 wxArrayVideoModes
 548 wxDisplay::DoGetModesDirectX(const wxVideoMode& WXUNUSED(modeMatch)) const
 549 {
 550     wxArrayVideoModes modes;
 551
 552     IDirectDraw2 *pDD = (*gs_displays)[m_index].m_pDD2;
 553
 554     if ( pDD )
 555     {
 556         HRESULT hr = pDD->EnumDisplayModes
 557                           (
 558                             DDEDM_REFRESHRATES,
 559                             NULL,   // all modes (TODO: use modeMatch!)
 560                             &modes,   // callback parameter
 561                             wxDDEnumModesCallback
 562                           );
 563
 564         if ( FAILED(hr) )
 565         {
 566             wxLogApiError(_T("IDirectDraw::EnumDisplayModes"), hr);
 567         }
 568     }
 569
 570     return modes;
 571 }
 572
 573 wxArrayVideoModes
 574 wxDisplay::DoGetModesWindows(const wxVideoMode& modeMatch) const
 575 {
 576     wxArrayVideoModes modes;
 577
 578     const wxString name = GetNameForEnumSettings();
 579
 580     const wxChar * const deviceName = name.empty() ? NULL : name.c_str();
 581
 582     DEVMODE dm;
 583     for ( int iModeNum = 0;
 584           ::EnumDisplaySettings(deviceName, iModeNum, &dm);
 585           iModeNum++ )
 586     {
 587         const wxVideoMode mode = ConvertToVideoMode(dm);
 588         if ( mode.Matches(modeMatch) )
 589         {
 590             modes.Add(mode);
 591         }
 592     }
 593
 594     return modes;
 595 }
 596
 597 wxArrayVideoModes wxDisplay::GetModes(const wxVideoMode& modeMatch) const
 598 {
 599     return gs_useDirectX ? DoGetModesDirectX(modeMatch)
 600                          : DoGetModesWindows(modeMatch);
 601 }
 602
 603 wxVideoMode wxDisplay::GetCurrentMode() const
 604 {
 605     wxVideoMode mode;
 606
 607     const wxString name = GetNameForEnumSettings();
 608
 609     DEVMODE dm;
 610     if ( !::EnumDisplaySettings(name.empty() ? NULL : name.c_str(),
 611                                 ENUM_CURRENT_SETTINGS,
 612                                 &dm) )
 613     {
 614         wxLogLastError(_T("EnumDisplaySettings(ENUM_CURRENT_SETTINGS)"));
 615     }
 616     else
 617     {
 618         mode = ConvertToVideoMode(dm);
 619     }
 620
 621     return mode;
 622 }
 623
 624 // ----------------------------------------------------------------------------
 625 // video mode switching
 626 // ----------------------------------------------------------------------------
 627
 628 bool wxDisplay::DoChangeModeDirectX(const wxVideoMode& mode)
 629 {
 630     IDirectDraw2 *pDD = (*gs_displays)[m_index].m_pDD2;
 631     if ( !pDD )
 632         return false;
 633
 634     wxWindow *winTop = wxTheApp->GetTopWindow();
 635     wxCHECK_MSG( winTop, false, _T("top level window required for DirectX") );
 636
 637     HRESULT hr = pDD->SetCooperativeLevel
 638                       (
 639                         GetHwndOf(winTop),
 640                         DDSCL_EXCLUSIVE | DDSCL_FULLSCREEN
 641                       );
 642     if ( FAILED(hr) )
 643     {
 644         wxLogApiError(_T("IDirectDraw::SetCooperativeLevel"), hr);
 645
 646         return false;
 647     }
 648
 649     hr = pDD->SetDisplayMode(mode.w, mode.h, mode.bpp, mode.refresh, 0);
 650     if ( FAILED(hr) )
 651     {
 652         wxLogApiError(_T("IDirectDraw::SetDisplayMode"), hr);
 653
 654         return false;
 655     }
 656
 657
 658     return true;
 659 }
 660
 661 bool wxDisplay::DoChangeModeWindows(const wxVideoMode& mode)
 662 {
 663     // prepare ChangeDisplaySettingsEx() parameters
 664     DEVMODE dm,
 665            *pDevMode;
 666     int flags;
 667
 668     if ( mode == wxDefaultVideoMode )
 669     {
 670         // reset the video mode to default
 671         pDevMode = NULL;
 672         flags = 0;
 673     }
 674     else // change to the given mode
 675     {
 676         wxCHECK_MSG( mode.w && mode.h, false,
 677                         _T("at least the width and height must be specified") );
 678
 679         wxZeroMemory(dm);
 680         dm.dmSize = sizeof(dm);
 681         dm.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT;
 682         dm.dmPelsWidth = mode.w;
 683         dm.dmPelsHeight = mode.h;
 684
 685         if ( mode.bpp )
 686         {
 687             dm.dmFields |= DM_BITSPERPEL;
 688             dm.dmBitsPerPel = mode.bpp;
 689         }
 690
 691         if ( mode.refresh )
 692         {
 693             dm.dmFields |= DM_DISPLAYFREQUENCY;
 694             dm.dmDisplayFrequency = mode.refresh;
 695         }
 696
 697         pDevMode = &dm;
 698
 699         flags = CDS_FULLSCREEN;
 700     }
 701
 702
 703     // get pointer to the function dynamically
 704     //
 705     // we're only called from the main thread, so it's ok to use static
 706     // variable
 707     static ChangeDisplaySettingsEx_t pfnChangeDisplaySettingsEx = NULL;
 708     if ( !pfnChangeDisplaySettingsEx )
 709     {
 710         wxDynamicLibrary dllUser32(_T("user32.dll"));
 711         if ( dllUser32.IsLoaded() )
 712         {
 713             pfnChangeDisplaySettingsEx = (ChangeDisplaySettingsEx_t)
 714                 dllUser32.GetSymbol(WINFUNC(ChangeDisplaySettingsEx));
 715         }
 716         //else: huh, no user32.dll??
 717
 718         if ( !pfnChangeDisplaySettingsEx )
 719         {
 720             // we must be under Win95 and so there is no multiple monitors
 721             // support anyhow
 722             pfnChangeDisplaySettingsEx = ChangeDisplaySettingsExForWin95;
 723         }
 724     }
 725
 726     // do change the mode
 727     switch ( pfnChangeDisplaySettingsEx
 728              (
 729                 GetName(),      // display name
 730                 pDevMode,       // dev mode or NULL to reset
 731                 NULL,           // reserved
 732                 flags,
 733                 NULL            // pointer to video parameters (not used)
 734              ) )
 735     {
 736         case DISP_CHANGE_SUCCESSFUL:
 737             // ok
 738             {
 739                 // If we have a top-level, full-screen frame, emulate
 740                 // the DirectX behavior and resize it.  This makes this
 741                 // API quite a bit easier to use.
 742                 wxWindow *winTop = wxTheApp->GetTopWindow();
 743                 wxFrame *frameTop = wxDynamicCast(winTop, wxFrame);
 744                 if (frameTop && frameTop->IsFullScreen())
 745                 {
 746                     wxVideoMode current = GetCurrentMode();
 747                     frameTop->SetClientSize(current.w, current.h);
 748                 }
 749             }
 750             return true;
 751
 752         case DISP_CHANGE_BADMODE:
 753             // don't complain about this, this is the only "expected" error
 754             break;
 755
 756         default:
 757             wxFAIL_MSG( _T("unexpected ChangeDisplaySettingsEx() return value") );
 758     }
 759
 760     return false;
 761 }
 762
 763 bool wxDisplay::ChangeMode(const wxVideoMode& mode)
 764 {
 765     return gs_useDirectX ? DoChangeModeDirectX(mode)
 766                          : DoChangeModeWindows(mode);
 767 }
 768
 769 #endif // wxUSE_DISPLAY
 770