(svn r26538) -Codechange: remove double accounting of the drivers

src/blitter/32bpp_anim.cpp

@@ -482,7 +482,7 @@ void Blitter_32bppAnim::PaletteAnimate(const Palette &palette)
 	}
 
 	/* Make sure the backend redraws the whole screen */
-	_video_driver->MakeDirty(0, 0, _screen.width, _screen.height);
+	VideoDriver::GetInstance()->MakeDirty(0, 0, _screen.width, _screen.height);
 }
 
 Blitter::PaletteAnimation Blitter_32bppAnim::UsePaletteAnimation()

src/bootstrap_gui.cpp

@@ -246,7 +246,7 @@ bool HandleBootstrap()
 	new BootstrapAskForDownloadWindow();
 
 	/* Process the user events. */
-	_video_driver->MainLoop();
+	VideoDriver::GetInstance()->MainLoop();
 
 	/* _exit_game is used to get out of the video driver's main loop.
 	 * In case GM_BOOTSTRAP is still set we did not exit it via the

src/console_gui.cpp

@@ -187,7 +187,7 @@ struct IConsoleWindow : Window
 	~IConsoleWindow()
 	{
 		_iconsole_mode = ICONSOLE_CLOSED;
-		_video_driver->EditBoxLostFocus();
+		VideoDriver::GetInstance()->EditBoxLostFocus();
 	}
 
 	/**
@@ -376,7 +376,7 @@ struct IConsoleWindow : Window
 
 	virtual void OnFocusLost()
 	{
-		_video_driver->EditBoxLostFocus();
+		VideoDriver::GetInstance()->EditBoxLostFocus();
 	}
 };
 

src/crashlog.cpp

@@ -140,14 +140,14 @@ char *CrashLog::LogConfiguration(char *buffer, const char *last) const
 			BaseGraphics::GetUsedSet() == NULL ? "none" : BaseGraphics::GetUsedSet()->name,
 			BaseGraphics::GetUsedSet() == NULL ? UINT32_MAX : BaseGraphics::GetUsedSet()->version,
 			_current_language == NULL ? "none" : _current_language->file,
-			_music_driver == NULL ? "none" : _music_driver->GetName(),
+			MusicDriver::GetInstance() == NULL ? "none" : MusicDriver::GetInstance()->GetName(),
 			BaseMusic::GetUsedSet() == NULL ? "none" : BaseMusic::GetUsedSet()->name,
 			BaseMusic::GetUsedSet() == NULL ? UINT32_MAX : BaseMusic::GetUsedSet()->version,
 			_networking ? (_network_server ? "server" : "client") : "no",
-			_sound_driver == NULL ? "none" : _sound_driver->GetName(),
+			SoundDriver::GetInstance() == NULL ? "none" : SoundDriver::GetInstance()->GetName(),
 			BaseSounds::GetUsedSet() == NULL ? "none" : BaseSounds::GetUsedSet()->name,
 			BaseSounds::GetUsedSet() == NULL ? UINT32_MAX : BaseSounds::GetUsedSet()->version,
-			_video_driver == NULL ? "none" : _video_driver->GetName()
+			VideoDriver::GetInstance() == NULL ? "none" : VideoDriver::GetInstance()->GetName()
 	);
 
 	buffer += seprintf(buffer, last,
@@ -484,7 +484,7 @@ bool CrashLog::MakeCrashLog() const
  */
 /* static */ void CrashLog::AfterCrashLogCleanup()
 {
-	if (_music_driver != NULL) _music_driver->Stop();
+	if (MusicDriver::GetInstance() != NULL) MusicDriver::GetInstance()->Stop();
-	if (_sound_driver != NULL) _sound_driver->Stop();
+	if (SoundDriver::GetInstance() != NULL) SoundDriver::GetInstance()->Stop();
-	if (_video_driver != NULL) _video_driver->Stop();
+	if (VideoDriver::GetInstance() != NULL) VideoDriver::GetInstance()->Stop();
 }

src/driver.cpp

@@ -18,17 +18,14 @@
 
 #include "safeguards.h"
 
-VideoDriver *_video_driver; ///< The currently active video driver.
 char *_ini_videodriver;     ///< The video driver a stored in the configuration file.
 int _num_resolutions;       ///< The number of resolutions.
 Dimension _resolutions[32]; ///< List of resolutions.
 Dimension _cur_resolution;  ///< The current resolution.
 bool _rightclick_emulate;   ///< Whether right clicking is emulated.
 
-SoundDriver *_sound_driver; ///< The currently active sound driver.
 char *_ini_sounddriver;     ///< The sound driver a stored in the configuration file.
 
-MusicDriver *_music_driver; ///< The currently active music driver.
 char *_ini_musicdriver;     ///< The music driver a stored in the configuration file.
 
 char *_ini_blitter;         ///< The blitter as stored in the configuration file.
@@ -88,9 +85,25 @@ int GetDriverParamInt(const char * const *parm, const char *name, int def)
  * @param type the type of driver to select
  * @post Sets the driver so GetCurrentDriver() returns it too.
  */
-Driver *DriverFactoryBase::SelectDriver(const char *name, Driver::Type type)
+void DriverFactoryBase::SelectDriver(const char *name, Driver::Type type)
 {
-	if (GetDrivers().size() == 0) return NULL;
+	if (!DriverFactoryBase::SelectDriverImpl(name, type)) {
+		StrEmpty(name) ?
+			usererror("Failed to autoprobe %s driver", GetDriverTypeName(type)) :
+			usererror("Failed to select requested %s driver '%s'", GetDriverTypeName(type), name);
+	}
+}
+
+/**
+ * Find the requested driver and return its class.
+ * @param name the driver to select.
+ * @param type the type of driver to select
+ * @post Sets the driver so GetCurrentDriver() returns it too.
+ * @return True upon success, otherwise false.
+ */
+bool DriverFactoryBase::SelectDriverImpl(const char *name, Driver::Type type)
+{
+	if (GetDrivers().size() == 0) return false;
 
 	if (StrEmpty(name)) {
 		/* Probe for this driver, but do not fall back to dedicated/null! */
@@ -109,7 +122,7 @@ Driver *DriverFactoryBase::SelectDriver(const char *name, Driver::Type type)
 					DEBUG(driver, 1, "Successfully probed %s driver '%s'", GetDriverTypeName(type), d->name);
 					delete *GetActiveDriver(type);
 					*GetActiveDriver(type) = newd;
-					return newd;
+					return true;
 				}
 
 				DEBUG(driver, 1, "Probing %s driver '%s' failed with error: %s", GetDriverTypeName(type), d->name, err);
@@ -160,7 +173,7 @@ Driver *DriverFactoryBase::SelectDriver(const char *name, Driver::Type type)
 			DEBUG(driver, 1, "Successfully loaded %s driver '%s'", GetDriverTypeName(type), d->name);
 			delete *GetActiveDriver(type);
 			*GetActiveDriver(type) = newd;
-			return newd;
+			return true;
 		}
 		usererror("No such %s driver: %s\n", GetDriverTypeName(type), buffer);
 	}

src/driver.h

@@ -59,6 +59,10 @@ DECLARE_POSTFIX_INCREMENT(Driver::Type)
 /** Base for all driver factories. */
 class DriverFactoryBase {
 private:
+	friend class MusicDriver;
+	friend class SoundDriver;
+	friend class VideoDriver;
+
 	Driver::Type type;       ///< The type of driver.
 	int priority;            ///< The priority of this factory.
 	const char *name;        ///< The name of the drivers of this factory.
@@ -97,6 +101,8 @@ private:
 		return driver_type_name[type];
 	}
 
+	static bool SelectDriverImpl(const char *name, Driver::Type type);
+
 protected:
 	DriverFactoryBase(Driver::Type type, int priority, const char *name, const char *description);
 
@@ -114,7 +120,7 @@ public:
 		}
 	}
 
-	static Driver *SelectDriver(const char *name, Driver::Type type);
+	static void SelectDriver(const char *name, Driver::Type type);
 	static char *GetDriversInfo(char *p, const char *last);
 
 	/**

src/genworld.cpp

@@ -331,7 +331,7 @@ void GenerateWorld(GenWorldMode mode, uint size_x, uint size_y, bool reset_setti
 		_gw.thread = NULL;
 	}
 
-	if (!_video_driver->HasGUI() || !ThreadObject::New(&_GenerateWorld, NULL, &_gw.thread)) {
+	if (!VideoDriver::GetInstance()->HasGUI() || !ThreadObject::New(&_GenerateWorld, NULL, &_gw.thread)) {
 		DEBUG(misc, 1, "Cannot create genworld thread, reverting to single-threaded mode");
 		_gw.threaded = false;
 		_modal_progress_work_mutex->EndCritical();

src/gfx.cpp

@@ -88,7 +88,7 @@ void GfxScroll(int left, int top, int width, int height, int xo, int yo)
 
 	blitter->ScrollBuffer(_screen.dst_ptr, left, top, width, height, xo, yo);
 	/* This part of the screen is now dirty. */
-	_video_driver->MakeDirty(left, top, width, height);
+	VideoDriver::GetInstance()->MakeDirty(left, top, width, height);
 }
 
 
@@ -1186,7 +1186,7 @@ void UndrawMouseCursor()
 		Blitter *blitter = BlitterFactory::GetCurrentBlitter();
 		_cursor.visible = false;
 		blitter->CopyFromBuffer(blitter->MoveTo(_screen.dst_ptr, _cursor.draw_pos.x, _cursor.draw_pos.y), _cursor_backup.GetBuffer(), _cursor.draw_size.x, _cursor.draw_size.y);
-		_video_driver->MakeDirty(_cursor.draw_pos.x, _cursor.draw_pos.y, _cursor.draw_size.x, _cursor.draw_size.y);
+		VideoDriver::GetInstance()->MakeDirty(_cursor.draw_pos.x, _cursor.draw_pos.y, _cursor.draw_size.x, _cursor.draw_size.y);
 	}
 }
 
@@ -1246,7 +1246,7 @@ void DrawMouseCursor()
 	_cur_dpi = &_screen;
 	DrawSprite(_cursor.sprite, _cursor.pal, _cursor.pos.x + _cursor.short_vehicle_offset, _cursor.pos.y);
 
-	_video_driver->MakeDirty(_cursor.draw_pos.x, _cursor.draw_pos.y, _cursor.draw_size.x, _cursor.draw_size.y);
+	VideoDriver::GetInstance()->MakeDirty(_cursor.draw_pos.x, _cursor.draw_pos.y, _cursor.draw_size.x, _cursor.draw_size.y);
 
 	_cursor.visible = true;
 	_cursor.dirty = false;
@@ -1270,7 +1270,7 @@ void RedrawScreenRect(int left, int top, int right, int bottom)
 
 	DrawOverlappedWindowForAll(left, top, right, bottom);
 
-	_video_driver->MakeDirty(left, top, right - left, bottom - top);
+	VideoDriver::GetInstance()->MakeDirty(left, top, right - left, bottom - top);
 }
 
 /**
@@ -1579,12 +1579,12 @@ void SetAnimatedMouseCursor(const AnimCursor *table)
 
 bool ChangeResInGame(int width, int height)
 {
-	return (_screen.width == width && _screen.height == height) || _video_driver->ChangeResolution(width, height);
+	return (_screen.width == width && _screen.height == height) || VideoDriver::GetInstance()->ChangeResolution(width, height);
 }
 
 bool ToggleFullScreen(bool fs)
 {
-	bool result = _video_driver->ToggleFullscreen(fs);
+	bool result = VideoDriver::GetInstance()->ToggleFullscreen(fs);
 	if (_fullscreen != fs && _num_resolutions == 0) {
 		DEBUG(driver, 0, "Could not find a suitable fullscreen resolution");
 	}

src/gfxinit.cpp

@@ -289,9 +289,9 @@ static bool SwitchNewGRFBlitter()
 		break;
 	}
 
-	if (!_video_driver->AfterBlitterChange()) {
+	if (!VideoDriver::GetInstance()->AfterBlitterChange()) {
 		/* Failed to switch blitter, let's hope we can return to the old one. */
-		if (BlitterFactory::SelectBlitter(cur_blitter) == NULL || !_video_driver->AfterBlitterChange()) usererror("Failed to reinitialize video driver. Specify a fixed blitter in the config");
+		if (BlitterFactory::SelectBlitter(cur_blitter) == NULL || !VideoDriver::GetInstance()->AfterBlitterChange()) usererror("Failed to reinitialize video driver. Specify a fixed blitter in the config");
 	}
 
 	return true;

src/music/extmidi.cpp

@@ -37,8 +37,8 @@ static FMusicDriver_ExtMidi iFMusicDriver_ExtMidi;
 
 const char *MusicDriver_ExtMidi::Start(const char * const * parm)
 {
-	if (strcmp(_video_driver->GetName(), "allegro") == 0 ||
+	if (strcmp(VideoDriver::GetInstance()->GetName(), "allegro") == 0 ||
-			strcmp(_sound_driver->GetName(), "allegro") == 0) {
+			strcmp(SoundDriver::GetInstance()->GetName(), "allegro") == 0) {
 		return "the extmidi driver does not work when Allegro is loaded.";
 	}
 

src/music/music_driver.hpp

@@ -39,9 +39,15 @@ public:
 	 * @param vol The new volume.
 	 */
 	virtual void SetVolume(byte vol) = 0;
+
+	/**
+	 * Get the currently active instance of the music driver.
+	 */
+	static MusicDriver *GetInstance() {
+		return static_cast<MusicDriver*>(*DriverFactoryBase::GetActiveDriver(Driver::DT_MUSIC));
+	}
 };
 
-extern MusicDriver *_music_driver;
 extern char *_ini_musicdriver;
 
 #endif /* MUSIC_MUSIC_DRIVER_HPP */

src/music_gui.cpp

@@ -176,7 +176,7 @@ static void SkipToNextSong()
 
 static void MusicVolumeChanged(byte new_vol)
 {
-	_music_driver->SetVolume(new_vol);
+	MusicDriver::GetInstance()->SetVolume(new_vol);
 }
 
 static void DoPlaySong()
@@ -185,13 +185,13 @@ static void DoPlaySong()
 	if (FioFindFullPath(filename, lastof(filename), BASESET_DIR, BaseMusic::GetUsedSet()->files[_music_wnd_cursong - 1].filename) == NULL) {
 		FioFindFullPath(filename, lastof(filename), OLD_GM_DIR, BaseMusic::GetUsedSet()->files[_music_wnd_cursong - 1].filename);
 	}
-	_music_driver->PlaySong(filename);
+	MusicDriver::GetInstance()->PlaySong(filename);
 	SetWindowDirty(WC_MUSIC_WINDOW, 0);
 }
 
 static void DoStopMusic()
 {
-	_music_driver->StopSong();
+	MusicDriver::GetInstance()->StopSong();
 	SetWindowDirty(WC_MUSIC_WINDOW, 0);
 }
 
@@ -273,7 +273,7 @@ void MusicLoop()
 
 	if (!_song_is_active) return;
 
-	if (!_music_driver->IsSongPlaying()) {
+	if (!MusicDriver::GetInstance()->IsSongPlaying()) {
 		if (_game_mode != GM_MENU) {
 			StopMusic();
 			SkipToNextSong();

src/network/network_chat_gui.cpp

@@ -169,7 +169,7 @@ void NetworkUndrawChatMessage()
 		/* Put our 'shot' back to the screen */
 		blitter->CopyFromBuffer(blitter->MoveTo(_screen.dst_ptr, x, y), _chatmessage_backup, width, height);
 		/* And make sure it is updated next time */
-		_video_driver->MakeDirty(x, y, width, height);
+		VideoDriver::GetInstance()->MakeDirty(x, y, width, height);
 
 		_chatmessage_dirty = true;
 	}
@@ -256,7 +256,7 @@ void NetworkDrawChatMessage()
 	}
 
 	/* Make sure the data is updated next flush */
-	_video_driver->MakeDirty(x, y, width, height);
+	VideoDriver::GetInstance()->MakeDirty(x, y, width, height);
 
 	_chatmessage_visible = true;
 	_chatmessage_dirty = false;

src/newgrf_config.cpp

@@ -775,7 +775,7 @@ void ScanNewGRFFiles(NewGRFScanCallback *callback)
 	/* Only then can we really start, especially by marking the whole screen dirty. Get those other windows hidden!. */
 	MarkWholeScreenDirty();
 
-	if (!_video_driver->HasGUI() || !ThreadObject::New(&DoScanNewGRFFiles, callback, NULL)) {
+	if (!VideoDriver::GetInstance()->HasGUI() || !ThreadObject::New(&DoScanNewGRFFiles, callback, NULL)) {
 		_modal_progress_work_mutex->EndCritical();
 		_modal_progress_paint_mutex->EndCritical();
 		DoScanNewGRFFiles(callback);

src/openttd.cpp

@@ -97,7 +97,7 @@ void CDECL usererror(const char *s, ...)
 	va_end(va);
 
 	ShowOSErrorBox(buf, false);
-	if (_video_driver != NULL) _video_driver->Stop();
+	if (VideoDriver::GetInstance() != NULL) VideoDriver::GetInstance()->Stop();
 
 	exit(1);
 }
@@ -343,7 +343,7 @@ static void LoadIntroGame(bool load_newgrfs = true)
 	CheckForMissingGlyphs();
 
 	/* Play main theme */
-	if (_music_driver->IsSongPlaying()) ResetMusic();
+	if (MusicDriver::GetInstance()->IsSongPlaying()) ResetMusic();
 }
 
 void MakeNewgameSettingsLive()
@@ -436,7 +436,7 @@ struct AfterNewGRFScan : NewGRFScanCallback {
 		*save_config_ptr = save_config;
 
 		/* restore saved music volume */
-		_music_driver->SetVolume(_settings_client.music.music_vol);
+		MusicDriver::GetInstance()->SetVolume(_settings_client.music.music_vol);
 
 		if (startyear != INVALID_YEAR) _settings_newgame.game_creation.starting_year = startyear;
 		if (generation_seed != GENERATE_NEW_SEED) _settings_newgame.game_creation.generation_seed = generation_seed;
@@ -775,12 +775,7 @@ int openttd_main(int argc, char *argv[])
 	free(blitter);
 
 	if (videodriver == NULL && _ini_videodriver != NULL) videodriver = stredup(_ini_videodriver);
-	_video_driver = (VideoDriver*)DriverFactoryBase::SelectDriver(videodriver, Driver::DT_VIDEO);
+	DriverFactoryBase::SelectDriver(videodriver, Driver::DT_VIDEO);
-	if (_video_driver == NULL) {
-		StrEmpty(videodriver) ?
-			usererror("Failed to autoprobe video driver") :
-			usererror("Failed to select requested video driver '%s'", videodriver);
-	}
 	free(videodriver);
 
 	InitializeSpriteSorter();
@@ -811,7 +806,7 @@ int openttd_main(int argc, char *argv[])
 		goto exit_bootstrap;
 	}
 
-	_video_driver->ClaimMousePointer();
+	VideoDriver::GetInstance()->ClaimMousePointer();
 
 	/* initialize screenshot formats */
 	InitializeScreenshotFormats();
@@ -843,21 +838,11 @@ int openttd_main(int argc, char *argv[])
 	free(music_set);
 
 	if (sounddriver == NULL && _ini_sounddriver != NULL) sounddriver = stredup(_ini_sounddriver);
-	_sound_driver = (SoundDriver*)DriverFactoryBase::SelectDriver(sounddriver, Driver::DT_SOUND);
+	DriverFactoryBase::SelectDriver(sounddriver, Driver::DT_SOUND);
-	if (_sound_driver == NULL) {
-		StrEmpty(sounddriver) ?
-			usererror("Failed to autoprobe sound driver") :
-			usererror("Failed to select requested sound driver '%s'", sounddriver);
-	}
 	free(sounddriver);
 
 	if (musicdriver == NULL && _ini_musicdriver != NULL) musicdriver = stredup(_ini_musicdriver);
-	_music_driver = (MusicDriver*)DriverFactoryBase::SelectDriver(musicdriver, Driver::DT_MUSIC);
+	DriverFactoryBase::SelectDriver(musicdriver, Driver::DT_MUSIC);
-	if (_music_driver == NULL) {
-		StrEmpty(musicdriver) ?
-			usererror("Failed to autoprobe music driver") :
-			usererror("Failed to select requested music driver '%s'", musicdriver);
-	}
 	free(musicdriver);
 
 	/* Take our initial lock on whatever we might want to do! */
@@ -875,7 +860,7 @@ int openttd_main(int argc, char *argv[])
 	ScanNewGRFFiles(scanner);
 	scanner = NULL;
 
-	_video_driver->MainLoop();
+	VideoDriver::GetInstance()->MainLoop();
 
 	WaitTillSaved();
 
@@ -943,7 +928,7 @@ static void MakeNewGameDone()
 	SettingsDisableElrail(_settings_game.vehicle.disable_elrails);
 
 	/* In a dedicated server, the server does not play */
-	if (!_video_driver->HasGUI()) {
+	if (!VideoDriver::GetInstance()->HasGUI()) {
 		SetLocalCompany(COMPANY_SPECTATOR);
 		if (_settings_client.gui.pause_on_newgame) DoCommandP(0, PM_PAUSED_NORMAL, 1, CMD_PAUSE);
 		IConsoleCmdExec("exec scripts/game_start.scr 0");
@@ -1509,6 +1494,6 @@ void GameLoop()
 
 	InputLoop();
 
-	_sound_driver->MainLoop();
+	SoundDriver::GetInstance()->MainLoop();
 	MusicLoop();
 }

src/os/windows/crashlog_win.cpp

@@ -523,7 +523,7 @@ static LONG WINAPI ExceptionHandler(EXCEPTION_POINTERS *ep)
 	/* Close any possible log files */
 	CloseConsoleLogIfActive();
 
-	if ((_video_driver == NULL || _video_driver->HasGUI()) && _safe_esp != NULL) {
+	if ((VideoDriver::GetInstance() == NULL || VideoDriver::GetInstance()->HasGUI()) && _safe_esp != NULL) {
 #ifdef _M_AMD64
 		ep->ContextRecord->Rip = (DWORD64)ShowCrashlogWindow;
 		ep->ContextRecord->Rsp = (DWORD64)_safe_esp;

src/osk_gui.cpp

@@ -208,7 +208,7 @@ struct OskWindow : public Window {
 
 	virtual void OnFocusLost()
 	{
-		_video_driver->EditBoxLostFocus();
+		VideoDriver::GetInstance()->EditBoxLostFocus();
 		delete this;
 	}
 };

src/sound/sound_driver.hpp

@@ -19,9 +19,15 @@ class SoundDriver : public Driver {
 public:
 	/** Called once every tick */
 	virtual void MainLoop() {}
+
+	/**
+	 * Get the currently active instance of the sound driver.
+	 */
+	static SoundDriver *GetInstance() {
+		return static_cast<SoundDriver*>(*DriverFactoryBase::GetActiveDriver(Driver::DT_SOUND));
+	}
 };
 
-extern SoundDriver *_sound_driver;
 extern char *_ini_sounddriver;
 
 #endif /* SOUND_SOUND_DRIVER_HPP */

src/video/cocoa/cocoa_v.mm

@@ -597,16 +597,16 @@ void CocoaDialog(const char *title, const char *message, const char *buttonLabel
 	_cocoa_video_dialog = true;
 
 	bool wasstarted = _cocoa_video_started;
-	if (_video_driver == NULL) {
+	if (VideoDriver::GetInstance() == NULL) {
 		setupApplication(); // Setup application before showing dialog
-	} else if (!_cocoa_video_started && _video_driver->Start(NULL) != NULL) {
+	} else if (!_cocoa_video_started && VideoDriver::GetInstance()->Start(NULL) != NULL) {
 		fprintf(stderr, "%s: %s\n", title, message);
 		return;
 	}
 
 	NSRunAlertPanel([ NSString stringWithUTF8String:title ], [ NSString stringWithUTF8String:message ], [ NSString stringWithUTF8String:buttonLabel ], nil, nil);
 
-	if (!wasstarted && _video_driver != NULL) _video_driver->Stop();
+	if (!wasstarted && VideoDriver::GetInstance() != NULL) VideoDriver::GetInstance()->Stop();
 
 	_cocoa_video_dialog = false;
 }

src/video/cocoa/event.mm

@@ -287,7 +287,7 @@ static bool QZ_KeyEvent(unsigned short keycode, unsigned short unicode, BOOL dow
 		case QZ_RETURN:
 		case QZ_f:
 			if (down && (_current_mods & NSCommandKeyMask)) {
-				_video_driver->ToggleFullscreen(!_fullscreen);
+				VideoDriver::GetInstance()->ToggleFullscreen(!_fullscreen);
 			}
 			break;
 	}

src/video/sdl_v.cpp

@@ -411,7 +411,7 @@ bool VideoDriver_SDL::CreateMainSurface(uint w, uint h)
 			break;
 
 		case Blitter::PALETTE_ANIMATION_BLITTER:
-			if (_video_driver != NULL) blitter->PaletteAnimate(_local_palette);
+			if (VideoDriver::GetInstance() != NULL) blitter->PaletteAnimate(_local_palette);
 			break;
 
 		default:

src/video/video_driver.hpp

@@ -78,9 +78,15 @@ public:
 	 * An edit box lost the input focus. Abort character compositing if necessary.
 	 */
 	virtual void EditBoxLostFocus() {}
+
+	/**
+	 * Get the currently active instance of the video driver.
+	 */
+	static VideoDriver *GetInstance() {
+		return static_cast<VideoDriver*>(*DriverFactoryBase::GetActiveDriver(Driver::DT_VIDEO));
+	}
 };
 
-extern VideoDriver *_video_driver;
 extern char *_ini_videodriver;
 extern int _num_resolutions;
 extern Dimension _resolutions[32];

src/video/win32_v.cpp

@@ -1002,7 +1002,7 @@ static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lP
 				if (active && minimized) {
 					/* Restore the game window */
 					ShowWindow(hwnd, SW_RESTORE);
-					static_cast<VideoDriver_Win32 *>(_video_driver)->MakeWindow(true);
+					static_cast<VideoDriver_Win32 *>(VideoDriver::GetInstance())->MakeWindow(true);
 				} else if (!active && !minimized) {
 					/* Minimise the window and restore desktop */
 					ShowWindow(hwnd, SW_MINIMIZE);

src/window.cpp

@@ -448,7 +448,7 @@ bool EditBoxInGlobalFocus()
 void Window::UnfocusFocusedWidget()
 {
 	if (this->nested_focus != NULL) {
-		if (this->nested_focus->type == WWT_EDITBOX) _video_driver->EditBoxLostFocus();
+		if (this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxLostFocus();
 
 		/* Repaint the widget that lost focus. A focused edit box may else leave the caret on the screen. */
 		this->nested_focus->SetDirty(this);
@@ -472,7 +472,7 @@ bool Window::SetFocusedWidget(int widget_index)
 
 		/* Repaint the widget that lost focus. A focused edit box may else leave the caret on the screen. */
 		this->nested_focus->SetDirty(this);
-		if (this->nested_focus->type == WWT_EDITBOX) _video_driver->EditBoxLostFocus();
+		if (this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxLostFocus();
 	}
 	this->nested_focus = this->GetWidget<NWidgetCore>(widget_index);
 	return true;
@@ -483,7 +483,7 @@ bool Window::SetFocusedWidget(int widget_index)
  */
 void Window::OnFocusLost()
 {
-	if (this->nested_focus != NULL && this->nested_focus->type == WWT_EDITBOX) _video_driver->EditBoxLostFocus();
+	if (this->nested_focus != NULL && this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxLostFocus();
 }
 
 /**