Codechange: Use null pointer literal instead of the NULL macro

5 files changed, 91 insertions, 91 deletions

diff --git a/src/video/allegro_v.cpp b/src/video/allegro_v.cpp
index c21f88d67..47dd92e1e 100644
--- a/src/video/allegro_v.cpp
+++ b/src/video/allegro_v.cpp
@@ -140,7 +140,7 @@ static void GetVideoModes()
 	set_gfx_mode(_fullscreen ? GFX_AUTODETECT_FULLSCREEN : GFX_AUTODETECT_WINDOWED, 640, 480, 0, 0);
 
 	GFX_MODE_LIST *mode_list = get_gfx_mode_list(gfx_driver->id);
-	if (mode_list == NULL) {
+	if (mode_list == nullptr) {
 		memcpy(_resolutions, default_resolutions, sizeof(default_resolutions));
 		_num_resolutions = lengthof(default_resolutions);
 		return;
@@ -243,7 +243,7 @@ static bool CreateMainSurface(uint w, uint h)
 bool VideoDriver_Allegro::ClaimMousePointer()
 {
 	select_mouse_cursor(MOUSE_CURSOR_NONE);
-	show_mouse(NULL);
+	show_mouse(nullptr);
 	disable_hardware_cursor();
 	return true;
 }
@@ -424,7 +424,7 @@ int _allegro_instance_count = 0;
 
 const char *VideoDriver_Allegro::Start(const char * const *parm)
 {
-	if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, NULL)) {
+	if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, nullptr)) {
 		DEBUG(driver, 0, "allegro: install_allegro failed '%s'", allegro_error);
 		return "Failed to set up Allegro";
 	}
@@ -437,8 +437,8 @@ const char *VideoDriver_Allegro::Start(const char * const *parm)
 #if defined _DEBUG
 /* Allegro replaces SEGV/ABRT signals meaning that the debugger will never
  * be triggered, so rereplace the signals and make the debugger useful. */
-	signal(SIGABRT, NULL);
-	signal(SIGSEGV, NULL);
+	signal(SIGABRT, nullptr);
+	signal(SIGSEGV, nullptr);
 #endif
 
 	GetVideoModes();
@@ -448,7 +448,7 @@ const char *VideoDriver_Allegro::Start(const char * const *parm)
 	MarkWholeScreenDirty();
 	set_close_button_callback(HandleExitGameRequest);
 
-	return NULL;
+	return nullptr;
 }
 
 void VideoDriver_Allegro::Stop()
@@ -463,7 +463,7 @@ static uint32 GetTime()
 {
 	struct timeval tim;
 
-	gettimeofday(&tim, NULL);
+	gettimeofday(&tim, nullptr);
 	return tim.tv_usec / 1000 + tim.tv_sec * 1000;
 }
 #else
diff --git a/src/video/dedicated_v.cpp b/src/video/dedicated_v.cpp
index 5af900080..8d767ce4d 100644
--- a/src/video/dedicated_v.cpp
+++ b/src/video/dedicated_v.cpp
@@ -87,7 +87,7 @@ static void WINAPI CheckForConsoleInput()
 	DWORD nb;
 	HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);
 	for (;;) {
-		ReadFile(hStdin, _win_console_thread_buffer, lengthof(_win_console_thread_buffer), &nb, NULL);
+		ReadFile(hStdin, _win_console_thread_buffer, lengthof(_win_console_thread_buffer), &nb, nullptr);
 		if (nb >= lengthof(_win_console_thread_buffer)) nb = lengthof(_win_console_thread_buffer) - 1;
 		_win_console_thread_buffer[nb] = '\0';
 
@@ -102,12 +102,12 @@ static void CreateWindowsConsoleThread()
 {
 	DWORD dwThreadId;
 	/* Create event to signal when console input is ready */
-	_hInputReady = CreateEvent(NULL, false, false, NULL);
-	_hWaitForInputHandling = CreateEvent(NULL, false, false, NULL);
-	if (_hInputReady == NULL || _hWaitForInputHandling == NULL) usererror("Cannot create console event!");
+	_hInputReady = CreateEvent(nullptr, false, false, nullptr);
+	_hWaitForInputHandling = CreateEvent(nullptr, false, false, nullptr);
+	if (_hInputReady == nullptr || _hWaitForInputHandling == nullptr) usererror("Cannot create console event!");
 
-	_hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)CheckForConsoleInput, NULL, 0, &dwThreadId);
-	if (_hThread == NULL) usererror("Cannot create console thread!");
+	_hThread = CreateThread(nullptr, 0, (LPTHREAD_START_ROUTINE)CheckForConsoleInput, nullptr, 0, &dwThreadId);
+	if (_hThread == nullptr) usererror("Cannot create console thread!");
 
 	DEBUG(driver, 2, "Windows console thread started");
 }
@@ -130,7 +130,7 @@ static void *_dedicated_video_mem;
 /* Whether a fork has been done. */
 bool _dedicated_forks;
 
-extern bool SafeLoad(const char *filename, SaveLoadOperation fop, DetailedFileType dft, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = NULL);
+extern bool SafeLoad(const char *filename, SaveLoadOperation fop, DetailedFileType dft, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = nullptr);
 
 static FVideoDriver_Dedicated iFVideoDriver_Dedicated;
 
@@ -138,7 +138,7 @@ static FVideoDriver_Dedicated iFVideoDriver_Dedicated;
 const char *VideoDriver_Dedicated::Start(const char * const *parm)
 {
 	int bpp = BlitterFactory::GetCurrentBlitter()->GetScreenDepth();
-	_dedicated_video_mem = (bpp == 0) ? NULL : MallocT<byte>(_cur_resolution.width * _cur_resolution.height * (bpp / 8));
+	_dedicated_video_mem = (bpp == 0) ? nullptr : MallocT<byte>(_cur_resolution.width * _cur_resolution.height * (bpp / 8));
 
 	_screen.width  = _screen.pitch = _cur_resolution.width;
 	_screen.height = _cur_resolution.height;
@@ -164,7 +164,7 @@ const char *VideoDriver_Dedicated::Start(const char * const *parm)
 #endif
 
 	DEBUG(driver, 1, "Loading dedicated server");
-	return NULL;
+	return nullptr;
 }
 
 void VideoDriver_Dedicated::Stop()
@@ -192,14 +192,14 @@ static bool InputWaiting()
 	FD_SET(STDIN, &readfds);
 
 	/* don't care about writefds and exceptfds: */
-	return select(STDIN + 1, &readfds, NULL, NULL, &tv) > 0;
+	return select(STDIN + 1, &readfds, nullptr, nullptr, &tv) > 0;
 }
 
 static uint32 GetTime()
 {
 	struct timeval tim;
 
-	gettimeofday(&tim, NULL);
+	gettimeofday(&tim, nullptr);
 	return tim.tv_usec / 1000 + tim.tv_sec * 1000;
 }
 
@@ -226,7 +226,7 @@ static void DedicatedHandleKeyInput()
 	if (_exit_game) return;
 
 #if defined(UNIX) || defined(__OS2__)
-	if (fgets(input_line, lengthof(input_line), stdin) == NULL) return;
+	if (fgets(input_line, lengthof(input_line), stdin) == nullptr) return;
 #else
 	/* Handle console input, and signal console thread, it can accept input again */
 	assert_compile(lengthof(_win_console_thread_buffer) <= lengthof(input_line));
diff --git a/src/video/null_v.cpp b/src/video/null_v.cpp
index 5037814e5..4ee2d05ce 100644
--- a/src/video/null_v.cpp
+++ b/src/video/null_v.cpp
@@ -29,13 +29,13 @@ const char *VideoDriver_Null::Start(const char * const *parm)
 	this->ticks = GetDriverParamInt(parm, "ticks", 1000);
 	_screen.width  = _screen.pitch = _cur_resolution.width;
 	_screen.height = _cur_resolution.height;
-	_screen.dst_ptr = NULL;
+	_screen.dst_ptr = nullptr;
 	ScreenSizeChanged();
 
 	/* Do not render, nor blit */
 	DEBUG(misc, 1, "Forcing blitter 'null'...");
 	BlitterFactory::SelectBlitter("null");
-	return NULL;
+	return nullptr;
 }
 
 void VideoDriver_Null::Stop() { }
diff --git a/src/video/sdl_v.cpp b/src/video/sdl_v.cpp
index 5e3fb4552..2f6184e85 100644
--- a/src/video/sdl_v.cpp
+++ b/src/video/sdl_v.cpp
@@ -39,9 +39,9 @@ static bool _all_modes;
 /** Whether the drawing is/may be done in a separate thread. */
 static bool _draw_threaded;
 /** Mutex to keep the access to the shared memory controlled. */
-static std::recursive_mutex *_draw_mutex = NULL;
+static std::recursive_mutex *_draw_mutex = nullptr;
 /** Signal to draw the next frame. */
-static std::condition_variable_any *_draw_signal = NULL;
+static std::condition_variable_any *_draw_signal = nullptr;
 /** Should we keep continue drawing? */
 static volatile bool _draw_continue;
 static Palette _local_palette;
@@ -111,7 +111,7 @@ static void UpdatePalette(bool init = false)
 		 * best mapping of shadow palette colors to real palette
 		 * colors from scratch.
 		 */
-		SDL_BlitSurface(_sdl_screen, NULL, _sdl_realscreen, NULL);
+		SDL_BlitSurface(_sdl_screen, nullptr, _sdl_realscreen, nullptr);
 		SDL_UpdateRect(_sdl_realscreen, 0, 0, 0, 0);
 	}
 }
@@ -158,7 +158,7 @@ static void DrawSurfaceToScreen()
 	_num_dirty_rects = 0;
 	if (n > MAX_DIRTY_RECTS) {
 		if (_sdl_screen != _sdl_realscreen) {
-			SDL_BlitSurface(_sdl_screen, NULL, _sdl_realscreen, NULL);
+			SDL_BlitSurface(_sdl_screen, nullptr, _sdl_realscreen, nullptr);
 		}
 		SDL_UpdateRect(_sdl_realscreen, 0, 0, 0, 0);
 	} else {
@@ -204,10 +204,10 @@ static const Dimension _default_resolutions[] = {
 
 static void GetVideoModes()
 {
-	SDL_Rect **modes = SDL_ListModes(NULL, SDL_SWSURFACE | SDL_FULLSCREEN);
-	if (modes == NULL) usererror("sdl: no modes available");
+	SDL_Rect **modes = SDL_ListModes(nullptr, SDL_SWSURFACE | SDL_FULLSCREEN);
+	if (modes == nullptr) usererror("sdl: no modes available");
 
-	_all_modes = (SDL_ListModes(NULL, SDL_SWSURFACE | (_fullscreen ? SDL_FULLSCREEN : 0)) == (void*)-1);
+	_all_modes = (SDL_ListModes(nullptr, SDL_SWSURFACE | (_fullscreen ? SDL_FULLSCREEN : 0)) == (void*)-1);
 	if (modes == (void*)-1) {
 		int n = 0;
 		for (uint i = 0; i < lengthof(_default_resolutions); i++) {
@@ -278,15 +278,15 @@ bool VideoDriver_SDL::CreateMainSurface(uint w, uint h)
 	if (bpp == 0) usererror("Can't use a blitter that blits 0 bpp for normal visuals");
 
 	char icon_path[MAX_PATH];
-	if (FioFindFullPath(icon_path, lastof(icon_path), BASESET_DIR, "openttd.32.bmp") != NULL) {
+	if (FioFindFullPath(icon_path, lastof(icon_path), BASESET_DIR, "openttd.32.bmp") != nullptr) {
 		/* Give the application an icon */
 		icon = SDL_LoadBMP(icon_path);
-		if (icon != NULL) {
+		if (icon != nullptr) {
 			/* Get the colourkey, which will be magenta */
 			uint32 rgbmap = SDL_MapRGB(icon->format, 255, 0, 255);
 
 			SDL_SetColorKey(icon, SDL_SRCCOLORKEY, rgbmap);
-			SDL_WM_SetIcon(icon, NULL);
+			SDL_WM_SetIcon(icon, nullptr);
 			SDL_FreeSurface(icon);
 		}
 	}
@@ -322,9 +322,9 @@ bool VideoDriver_SDL::CreateMainSurface(uint w, uint h)
 	if (want_hwpalette) DEBUG(driver, 1, "SDL: requesting hardware palette");
 
 	/* Free any previously allocated shadow surface */
-	if (_sdl_screen != NULL && _sdl_screen != _sdl_realscreen) SDL_FreeSurface(_sdl_screen);
+	if (_sdl_screen != nullptr && _sdl_screen != _sdl_realscreen) SDL_FreeSurface(_sdl_screen);
 
-	if (_sdl_realscreen != NULL) {
+	if (_sdl_realscreen != nullptr) {
 		if (_requested_hwpalette != want_hwpalette) {
 			/* SDL (at least the X11 driver), reuses the
 			 * same window and palette settings when the bpp
@@ -349,7 +349,7 @@ bool VideoDriver_SDL::CreateMainSurface(uint w, uint h)
 
 	/* DO NOT CHANGE TO HWSURFACE, IT DOES NOT WORK */
 	newscreen = SDL_SetVideoMode(w, h, bpp, SDL_SWSURFACE | (want_hwpalette ? SDL_HWPALETTE : 0) | (_fullscreen ? SDL_FULLSCREEN : SDL_RESIZABLE));
-	if (newscreen == NULL) {
+	if (newscreen == nullptr) {
 		DEBUG(driver, 0, "SDL: Couldn't allocate a window to draw on");
 		return false;
 	}
@@ -376,7 +376,7 @@ bool VideoDriver_SDL::CreateMainSurface(uint w, uint h)
 		 */
 		DEBUG(driver, 1, "SDL: using shadow surface");
 		newscreen = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, bpp, 0, 0, 0, 0);
-		if (newscreen == NULL) {
+		if (newscreen == nullptr) {
 			DEBUG(driver, 0, "SDL: Couldn't allocate a shadow surface to draw on");
 			return false;
 		}
@@ -637,9 +637,9 @@ const char *VideoDriver_SDL::Start(const char * const *parm)
 	MarkWholeScreenDirty();
 	SetupKeyboard();
 
-	_draw_threaded = GetDriverParam(parm, "no_threads") == NULL && GetDriverParam(parm, "no_thread") == NULL;
+	_draw_threaded = GetDriverParam(parm, "no_threads") == nullptr && GetDriverParam(parm, "no_thread") == nullptr;
 
-	return NULL;
+	return nullptr;
 }
 
 void VideoDriver_SDL::SetupKeyboard()
@@ -673,7 +673,7 @@ void VideoDriver_SDL::MainLoop()
 		/* Initialise the mutex first, because that's the thing we *need*
 		 * directly in the newly created thread. */
 		_draw_mutex = new std::recursive_mutex();
-		if (_draw_mutex == NULL) {
+		if (_draw_mutex == nullptr) {
 			_draw_threaded = false;
 		} else {
 			draw_lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
@@ -688,8 +688,8 @@ void VideoDriver_SDL::MainLoop()
 				draw_lock.release();
 				delete _draw_mutex;
 				delete _draw_signal;
-				_draw_mutex = NULL;
-				_draw_signal = NULL;
+				_draw_mutex = nullptr;
+				_draw_signal = nullptr;
 			} else {
 				/* Wait till the draw mutex has started itself. */
 				_draw_signal->wait(*_draw_mutex);
@@ -757,26 +757,26 @@ void VideoDriver_SDL::MainLoop()
 
 			/* The gameloop is the part that can run asynchronously. The rest
 			 * except sleeping can't. */
-			if (_draw_mutex != NULL) draw_lock.unlock();
+			if (_draw_mutex != nullptr) draw_lock.unlock();
 
 			GameLoop();
 
-			if (_draw_mutex != NULL) draw_lock.lock();
+			if (_draw_mutex != nullptr) draw_lock.lock();
 
 			UpdateWindows();
 			_local_palette = _cur_palette;
 		} else {
 			/* Release the thread while sleeping */
-			if (_draw_mutex != NULL) draw_lock.unlock();
+			if (_draw_mutex != nullptr) draw_lock.unlock();
 			CSleep(1);
-			if (_draw_mutex != NULL) draw_lock.lock();
+			if (_draw_mutex != nullptr) draw_lock.lock();
 
 			NetworkDrawChatMessage();
 			DrawMouseCursor();
 		}
 
 		/* End of the critical part. */
-		if (_draw_mutex != NULL && !HasModalProgress()) {
+		if (_draw_mutex != nullptr && !HasModalProgress()) {
 			_draw_signal->notify_one();
 		} else {
 			/* Oh, we didn't have threads, then just draw unthreaded */
@@ -785,7 +785,7 @@ void VideoDriver_SDL::MainLoop()
 		}
 	}
 
-	if (_draw_mutex != NULL) {
+	if (_draw_mutex != nullptr) {
 		_draw_continue = false;
 		/* Sending signal if there is no thread blocked
 		 * is very valid and results in noop */
@@ -797,15 +797,15 @@ void VideoDriver_SDL::MainLoop()
 		delete _draw_mutex;
 		delete _draw_signal;
 
-		_draw_mutex = NULL;
-		_draw_signal = NULL;
+		_draw_mutex = nullptr;
+		_draw_signal = nullptr;
 	}
 }
 
 bool VideoDriver_SDL::ChangeResolution(int w, int h)
 {
 	std::unique_lock<std::recursive_mutex> lock;
-	if (_draw_mutex != NULL) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
+	if (_draw_mutex != nullptr) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
 
 	return CreateMainSurface(w, h);
 }
@@ -813,7 +813,7 @@ bool VideoDriver_SDL::ChangeResolution(int w, int h)
 bool VideoDriver_SDL::ToggleFullscreen(bool fullscreen)
 {
 	std::unique_lock<std::recursive_mutex> lock;
-	if (_draw_mutex != NULL) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
+	if (_draw_mutex != nullptr) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
 
 	_fullscreen = fullscreen;
 	GetVideoModes(); // get the list of available video modes
@@ -834,12 +834,12 @@ bool VideoDriver_SDL::AfterBlitterChange()
 
 void VideoDriver_SDL::AcquireBlitterLock()
 {
-	if (_draw_mutex != NULL) _draw_mutex->lock();
+	if (_draw_mutex != nullptr) _draw_mutex->lock();
 }
 
 void VideoDriver_SDL::ReleaseBlitterLock()
 {
-	if (_draw_mutex != NULL) _draw_mutex->unlock();
+	if (_draw_mutex != nullptr) _draw_mutex->unlock();
 }
 
 #endif /* WITH_SDL */
diff --git a/src/video/win32_v.cpp b/src/video/win32_v.cpp
index 382c0d8fc..7eea4782a 100644
--- a/src/video/win32_v.cpp
+++ b/src/video/win32_v.cpp
@@ -42,7 +42,7 @@
 #endif
 
 typedef BOOL (WINAPI *PFNTRACKMOUSEEVENT)(LPTRACKMOUSEEVENT lpEventTrack);
-static PFNTRACKMOUSEEVENT _pTrackMouseEvent = NULL;
+static PFNTRACKMOUSEEVENT _pTrackMouseEvent = nullptr;
 
 static struct {
 	HWND main_wnd;
@@ -68,9 +68,9 @@ DWORD _imm_props;
 /** Whether the drawing is/may be done in a separate thread. */
 static bool _draw_threaded;
 /** Mutex to keep the access to the shared memory controlled. */
-static std::recursive_mutex *_draw_mutex = NULL;
+static std::recursive_mutex *_draw_mutex = nullptr;
 /** Signal to draw the next frame. */
-static std::condition_variable_any *_draw_signal = NULL;
+static std::condition_variable_any *_draw_signal = nullptr;
 /** Should we keep continue drawing? */
 static volatile bool _draw_continue;
 /** Local copy of the palette for use in the drawing thread. */
@@ -91,7 +91,7 @@ static void MakePalette()
 
 	}
 	_wnd.gdi_palette = CreatePalette(pal);
-	if (_wnd.gdi_palette == NULL) usererror("CreatePalette failed!\n");
+	if (_wnd.gdi_palette == nullptr) usererror("CreatePalette failed!\n");
 
 	_cur_palette.first_dirty = 0;
 	_cur_palette.count_dirty = 256;
@@ -309,7 +309,7 @@ bool VideoDriver_Win32::MakeWindow(bool full_screen)
 		}
 	} else if (_wnd.fullscreen) {
 		/* restore display? */
-		ChangeDisplaySettings(NULL, 0);
+		ChangeDisplaySettings(nullptr, 0);
 		/* restore the resolution */
 		_wnd.width = _bck_resolution.width;
 		_wnd.height = _bck_resolution.height;
@@ -336,7 +336,7 @@ bool VideoDriver_Win32::MakeWindow(bool full_screen)
 		w = r.right - r.left;
 		h = r.bottom - r.top;
 
-		if (_wnd.main_wnd != NULL) {
+		if (_wnd.main_wnd != nullptr) {
 			if (!_window_maximize) SetWindowPos(_wnd.main_wnd, 0, 0, 0, w, h, SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOZORDER | SWP_NOMOVE);
 		} else {
 			int x = (GetSystemMetrics(SM_CXSCREEN) - w) / 2;
@@ -345,8 +345,8 @@ bool VideoDriver_Win32::MakeWindow(bool full_screen)
 			char window_title[64];
 			seprintf(window_title, lastof(window_title), "OpenTTD %s", _openttd_revision);
 
-			_wnd.main_wnd = CreateWindow(_T("OTTD"), MB_TO_WIDE(window_title), style, x, y, w, h, 0, 0, GetModuleHandle(NULL), 0);
-			if (_wnd.main_wnd == NULL) usererror("CreateWindow failed");
+			_wnd.main_wnd = CreateWindow(_T("OTTD"), MB_TO_WIDE(window_title), style, x, y, w, h, 0, 0, GetModuleHandle(nullptr), 0);
+			if (_wnd.main_wnd == nullptr) usererror("CreateWindow failed");
 			ShowWindow(_wnd.main_wnd, showstyle);
 		}
 	}
@@ -559,14 +559,14 @@ static LRESULT HandleIMEComposition(HWND hwnd, WPARAM wParam, LPARAM lParam)
 	if (hIMC != NULL) {
 		if (lParam & GCS_RESULTSTR) {
 			/* Read result string from the IME. */
-			LONG len = ImmGetCompositionString(hIMC, GCS_RESULTSTR, NULL, 0); // Length is always in bytes, even in UNICODE build.
+			LONG len = ImmGetCompositionString(hIMC, GCS_RESULTSTR, nullptr, 0); // Length is always in bytes, even in UNICODE build.
 			TCHAR *str = (TCHAR *)_alloca(len + sizeof(TCHAR));
 			len = ImmGetCompositionString(hIMC, GCS_RESULTSTR, str, len);
 			str[len / sizeof(TCHAR)] = '\0';
 
 			/* Transmit text to windowing system. */
 			if (len > 0) {
-				HandleTextInput(NULL, true); // Clear marked string.
+				HandleTextInput(nullptr, true); // Clear marked string.
 				HandleTextInput(FS2OTTD(str));
 			}
 			SetCompositionPos(hwnd);
@@ -577,7 +577,7 @@ static LRESULT HandleIMEComposition(HWND hwnd, WPARAM wParam, LPARAM lParam)
 
 		if ((lParam & GCS_COMPSTR) && DrawIMECompositionString()) {
 			/* Read composition string from the IME. */
-			LONG len = ImmGetCompositionString(hIMC, GCS_COMPSTR, NULL, 0); // Length is always in bytes, even in UNICODE build.
+			LONG len = ImmGetCompositionString(hIMC, GCS_COMPSTR, nullptr, 0); // Length is always in bytes, even in UNICODE build.
 			TCHAR *str = (TCHAR *)_alloca(len + sizeof(TCHAR));
 			len = ImmGetCompositionString(hIMC, GCS_COMPSTR, str, len);
 			str[len / sizeof(TCHAR)] = '\0';
@@ -587,7 +587,7 @@ static LRESULT HandleIMEComposition(HWND hwnd, WPARAM wParam, LPARAM lParam)
 				convert_from_fs(str, utf8_buf, lengthof(utf8_buf));
 
 				/* Convert caret position from bytes in the input string to a position in the UTF-8 encoded string. */
-				LONG caret_bytes = ImmGetCompositionString(hIMC, GCS_CURSORPOS, NULL, 0);
+				LONG caret_bytes = ImmGetCompositionString(hIMC, GCS_CURSORPOS, nullptr, 0);
 				const char *caret = utf8_buf;
 				for (const TCHAR *c = str; *c != '\0' && *caret != '\0' && caret_bytes > 0; c++, caret_bytes--) {
 					/* Skip DBCS lead bytes or leading surrogates. */
@@ -604,7 +604,7 @@ static LRESULT HandleIMEComposition(HWND hwnd, WPARAM wParam, LPARAM lParam)
 
 				HandleTextInput(utf8_buf, true, caret);
 			} else {
-				HandleTextInput(NULL, true);
+				HandleTextInput(nullptr, true);
 			}
 
 			lParam &= ~(GCS_COMPSTR | GCS_COMPATTR | GCS_COMPCLAUSE | GCS_CURSORPOS | GCS_DELTASTART);
@@ -622,7 +622,7 @@ static void CancelIMEComposition(HWND hwnd)
 	if (hIMC != NULL) ImmNotifyIME(hIMC, NI_COMPOSITIONSTR, CPS_CANCEL, 0);
 	ImmReleaseContext(hwnd, hIMC);
 	/* Clear any marked string from the current edit box. */
-	HandleTextInput(NULL, true);
+	HandleTextInput(nullptr, true);
 }
 
 static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
@@ -647,14 +647,14 @@ static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lP
 			break;
 
 		case WM_PAINT:
-			if (!in_sizemove && _draw_mutex != NULL && !HasModalProgress()) {
+			if (!in_sizemove && _draw_mutex != nullptr && !HasModalProgress()) {
 				/* Get the union of the old update rect and the new update rect. */
 				RECT r;
 				GetUpdateRect(hwnd, &r, FALSE);
 				UnionRect(&_wnd.update_rect, &_wnd.update_rect, &r);
 
 				/* Mark the window as updated, otherwise Windows would send more WM_PAINT messages. */
-				ValidateRect(hwnd, NULL);
+				ValidateRect(hwnd, nullptr);
 				_draw_signal->notify_one();
 			} else {
 				PAINTSTRUCT ps;
@@ -676,7 +676,7 @@ static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lP
 
 			SelectPalette(hDC, hOldPalette, TRUE);
 			ReleaseDC(hwnd, hDC);
-			if (nChanged != 0) InvalidateRect(hwnd, NULL, FALSE);
+			if (nChanged != 0) InvalidateRect(hwnd, nullptr, FALSE);
 			return 0;
 		}
 
@@ -730,7 +730,7 @@ static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lP
 			 * tracking the mouse for exiting the window */
 			if (!_cursor.in_window) {
 				_cursor.in_window = true;
-				if (_pTrackMouseEvent != NULL) {
+				if (_pTrackMouseEvent != nullptr) {
 					TRACKMOUSEEVENT tme;
 					tme.cbSize = sizeof(tme);
 					tme.dwFlags = TME_LEAVE;
@@ -783,7 +783,7 @@ static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lP
 
 		case WM_IME_ENDCOMPOSITION:
 			/* Clear any pending composition string. */
-			HandleTextInput(NULL, true);
+			HandleTextInput(nullptr, true);
 			if (DrawIMECompositionString()) return 0;
 			break;
 
@@ -831,7 +831,7 @@ static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lP
 
 			/* Silently drop all messages handled by WM_CHAR. */
 			MSG msg;
-			if (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
+			if (PeekMessage(&msg, nullptr, 0, 0, PM_NOREMOVE)) {
 				if ((msg.message == WM_CHAR || msg.message == WM_DEADCHAR) && GB(lParam, 16, 8) == GB(msg.lParam, 16, 8)) {
 					return 0;
 				}
@@ -993,7 +993,7 @@ static LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lP
 				} else if (!active && !minimized) {
 					/* Minimise the window and restore desktop */
 					ShowWindow(hwnd, SW_MINIMIZE);
-					ChangeDisplaySettings(NULL, 0);
+					ChangeDisplaySettings(nullptr, 0);
 				}
 			}
 			break;
@@ -1008,7 +1008,7 @@ static void RegisterWndClass()
 	static bool registered = false;
 
 	if (!registered) {
-		HINSTANCE hinst = GetModuleHandle(NULL);
+		HINSTANCE hinst = GetModuleHandle(nullptr);
 		WNDCLASS wnd = {
 			CS_OWNDC,
 			WndProcGdi,
@@ -1016,7 +1016,7 @@ static void RegisterWndClass()
 			0,
 			hinst,
 			LoadIcon(hinst, MAKEINTRESOURCE(100)),
-			LoadCursor(NULL, IDC_ARROW),
+			LoadCursor(nullptr, IDC_ARROW),
 			0,
 			0,
 			_T("OTTD")
@@ -1057,8 +1057,8 @@ static bool AllocateDibSection(int w, int h, bool force)
 	if (_wnd.dib_sect) DeleteObject(_wnd.dib_sect);
 
 	dc = GetDC(0);
-	_wnd.dib_sect = CreateDIBSection(dc, bi, DIB_RGB_COLORS, (VOID**)&_wnd.buffer_bits, NULL, 0);
-	if (_wnd.dib_sect == NULL) usererror("CreateDIBSection failed");
+	_wnd.dib_sect = CreateDIBSection(dc, bi, DIB_RGB_COLORS, (VOID**)&_wnd.buffer_bits, nullptr, 0);
+	if (_wnd.dib_sect == nullptr) usererror("CreateDIBSection failed");
 	ReleaseDC(0, dc);
 
 	_screen.width = w;
@@ -1095,7 +1095,7 @@ static void FindResolutions()
 	/* XXX - EnumDisplaySettingsW crashes with unicows.dll on Windows95
 	 * Doesn't really matter since we don't pass a string anyways, but still
 	 * a letdown */
-	for (i = 0; EnumDisplaySettingsA(NULL, i, &dm) != 0; i++) {
+	for (i = 0; EnumDisplaySettingsA(nullptr, i, &dm) != 0; i++) {
 		if (dm.dmBitsPerPel == bpp &&
 				dm.dmPelsWidth >= 640 && dm.dmPelsHeight >= 480) {
 			uint j;
@@ -1149,9 +1149,9 @@ const char *VideoDriver_Win32::Start(const char * const *parm)
 
 	MarkWholeScreenDirty();
 
-	_draw_threaded = GetDriverParam(parm, "no_threads") == NULL && GetDriverParam(parm, "no_thread") == NULL && std::thread::hardware_concurrency() > 1;
+	_draw_threaded = GetDriverParam(parm, "no_threads") == nullptr && GetDriverParam(parm, "no_thread") == nullptr && std::thread::hardware_concurrency() > 1;
 
-	return NULL;
+	return nullptr;
 }
 
 void VideoDriver_Win32::Stop()
@@ -1160,7 +1160,7 @@ void VideoDriver_Win32::Stop()
 	DeleteObject(_wnd.dib_sect);
 	DestroyWindow(_wnd.main_wnd);
 
-	if (_wnd.fullscreen) ChangeDisplaySettings(NULL, 0);
+	if (_wnd.fullscreen) ChangeDisplaySettings(nullptr, 0);
 	MyShowCursor(true);
 }
 
@@ -1176,7 +1176,7 @@ static void CheckPaletteAnim()
 	if (_cur_palette.count_dirty == 0) return;
 
 	_local_palette = _cur_palette;
-	InvalidateRect(_wnd.main_wnd, NULL, FALSE);
+	InvalidateRect(_wnd.main_wnd, nullptr, FALSE);
 }
 
 void VideoDriver_Win32::MainLoop()
@@ -1211,8 +1211,8 @@ void VideoDriver_Win32::MainLoop()
 				draw_lock.release();
 				delete _draw_mutex;
 				delete _draw_signal;
-				_draw_mutex = NULL;
-				_draw_signal = NULL;
+				_draw_mutex = nullptr;
+				_draw_signal = nullptr;
 			} else {
 				DEBUG(driver, 1, "Threaded drawing enabled");
 				/* Wait till the draw thread has started itself. */
@@ -1227,7 +1227,7 @@ void VideoDriver_Win32::MainLoop()
 	for (;;) {
 		uint32 prev_cur_ticks = cur_ticks; // to check for wrapping
 
-		while (PeekMessage(&mesg, NULL, 0, 0, PM_REMOVE)) {
+		while (PeekMessage(&mesg, nullptr, 0, 0, PM_REMOVE)) {
 			InteractiveRandom(); // randomness
 			/* Convert key messages to char messages if we want text input. */
 			if (EditBoxInGlobalFocus()) TranslateMessage(&mesg);
@@ -1310,14 +1310,14 @@ void VideoDriver_Win32::MainLoop()
 		delete _draw_mutex;
 		delete _draw_signal;
 
-		_draw_mutex = NULL;
+		_draw_mutex = nullptr;
 	}
 }
 
 bool VideoDriver_Win32::ChangeResolution(int w, int h)
 {
 	std::unique_lock<std::recursive_mutex> lock;
-	if (_draw_mutex != NULL) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
+	if (_draw_mutex != nullptr) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
 
 	if (_window_maximize) ShowWindow(_wnd.main_wnd, SW_SHOWNORMAL);
 
@@ -1330,7 +1330,7 @@ bool VideoDriver_Win32::ChangeResolution(int w, int h)
 bool VideoDriver_Win32::ToggleFullscreen(bool full_screen)
 {
 	std::unique_lock<std::recursive_mutex> lock;
-	if (_draw_mutex != NULL) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
+	if (_draw_mutex != nullptr) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
 
 	return this->MakeWindow(full_screen);
 }
@@ -1342,18 +1342,18 @@ bool VideoDriver_Win32::AfterBlitterChange()
 
 void VideoDriver_Win32::AcquireBlitterLock()
 {
-	if (_draw_mutex != NULL) _draw_mutex->lock();
+	if (_draw_mutex != nullptr) _draw_mutex->lock();
 }
 
 void VideoDriver_Win32::ReleaseBlitterLock()
 {
-	if (_draw_mutex != NULL) _draw_mutex->unlock();
+	if (_draw_mutex != nullptr) _draw_mutex->unlock();
 }
 
 void VideoDriver_Win32::EditBoxLostFocus()
 {
 	std::unique_lock<std::recursive_mutex> lock;
-	if (_draw_mutex != NULL) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
+	if (_draw_mutex != nullptr) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
 
 	CancelIMEComposition(_wnd.main_wnd);
 	SetCompositionPos(_wnd.main_wnd);