HOPKINS: Remove g_PTRNUL

15 files changed, 168 insertions, 177 deletions

diff --git a/engines/hopkins/anim.cpp b/engines/hopkins/anim.cpp
index 37eb4adc73..24b4c4e5d6 100644
--- a/engines/hopkins/anim.cpp
+++ b/engines/hopkins/anim.cpp
@@ -531,7 +531,7 @@ void AnimationManager::searchAnim(const byte *data, int animIndex, int bufSize)
 						innerLoopCond = true;
 					if (bufSize < curBufferPos) {
 						_animBqe[animIndex]._enabledFl = false;
-						_animBqe[animIndex]._data = g_PTRNUL;
+						_animBqe[animIndex]._data = NULL;
 						return;
 					}
 					++curBufferPos;
@@ -817,12 +817,12 @@ void AnimationManager::playSequence2(const Common::String &file, uint32 rate1, u
 
 void AnimationManager::initAnimBqe() {
 	for (int idx = 0; idx < 35; ++idx) {
-		_animBqe[idx]._data = g_PTRNUL;
+		_animBqe[idx]._data = NULL;
 		_animBqe[idx]._enabledFl = false;
 	}
 
 	for (int idx = 0; idx < 8; ++idx) {
-		Bank[idx]._data = g_PTRNUL;
+		Bank[idx]._data = NULL;
 		Bank[idx]._loadedFl = false;
 		Bank[idx]._filename = "";
 		Bank[idx]._fileHeader = 0;
diff --git a/engines/hopkins/computer.cpp b/engines/hopkins/computer.cpp
index fea8ba9b58..09ce5080b8 100644
--- a/engines/hopkins/computer.cpp
+++ b/engines/hopkins/computer.cpp
@@ -44,9 +44,9 @@ ComputerManager::ComputerManager(HopkinsEngine *vm) {
 		memset(_menuText[i]._line, 0, 90);
 	}
 	Common::fill(&_inputBuf[0], &_inputBuf[200], '\0');
-	_breakoutSpr = g_PTRNUL;
+	_breakoutSpr = NULL;
 	_textColor = 0;
-	_breakoutLevel = (int16 *)g_PTRNUL;
+	_breakoutLevel = (int16 *)NULL;
 	_breakoutBrickNbr = 0;
 	_breakoutScore = 0;
 	_breakoutLives = 0;
@@ -536,9 +536,9 @@ void ComputerManager::displayGamesSubMenu() {
 
 	_vm->_globals->_speed = 1;
 	_vm->_eventsManager->changeMouseCursor(0);
-	_breakoutSpr = g_PTRNUL;
+	_breakoutSpr = NULL;
 	_vm->_eventsManager->_breakoutFl = true;
-	_breakoutLevel = (int16 *)g_PTRNUL;
+	_breakoutLevel = (int16 *)NULL;
 	_breakoutBrickNbr = 0;
 	_breakoutScore = 0;
 	_breakoutLives = 5;
diff --git a/engines/hopkins/dialogs.cpp b/engines/hopkins/dialogs.cpp
index d756f0db6f..caffed67eb 100644
--- a/engines/hopkins/dialogs.cpp
+++ b/engines/hopkins/dialogs.cpp
@@ -44,9 +44,9 @@ DialogsManager::DialogsManager(HopkinsEngine *vm) {
 	_removeInventFl = false;
 	_inventX = _inventY = 0;
 	_inventWidth = _inventHeight = 0;
-	_inventWin1 = g_PTRNUL;
-	_inventBuf2 = g_PTRNUL;
-	_inventoryIcons = g_PTRNUL;
+	_inventWin1 = NULL;
+	_inventBuf2 = NULL;
+	_inventoryIcons = NULL;
 }
 
 DialogsManager::~DialogsManager() {
@@ -56,8 +56,8 @@ DialogsManager::~DialogsManager() {
 }
 
 void DialogsManager::clearAll() {
-	_inventWin1 = g_PTRNUL;
-	_inventBuf2 = g_PTRNUL;
+	_inventWin1 = NULL;
+	_inventBuf2 = NULL;
 }
 
 void DialogsManager::loadIcons() {
@@ -341,7 +341,7 @@ void DialogsManager::showInventory() {
 		_vm->_eventsManager->getMouseY();
 		_vm->_eventsManager->refreshScreenAndEvents();
 	}
-	_inventWin1 = g_PTRNUL;
+	_inventWin1 = NULL;
 
 	bool loopFl;
 	do {
diff --git a/engines/hopkins/events.cpp b/engines/hopkins/events.cpp
index 8ff91ea02a..21578b02a0 100644
--- a/engines/hopkins/events.cpp
+++ b/engines/hopkins/events.cpp
@@ -44,14 +44,14 @@ EventsManager::EventsManager(HopkinsEngine *vm) {
 	_mouseSpriteId = 0;
 	_curMouseButton = 0;
 	_mouseButton = 0;
-	_mouseCursor = g_PTRNUL;
+	_mouseCursor = NULL;
 	_gameCounter = 0;
 	_rateCounter = 0;
 	_escKeyFl = false;
 	_gameKey = KEY_NONE;
 	_mouseCursorId = 0;
 	_oldIconId = 0;
-	_objectBuf = g_PTRNUL;
+	_objectBuf = NULL;
 
 	Common::fill(&_keyState[0], &_keyState[256], false);
 	_priorCounterTime = 0;
diff --git a/engines/hopkins/files.cpp b/engines/hopkins/files.cpp
index 3f7c4e48dd..2390ebbdf8 100644
--- a/engines/hopkins/files.cpp
+++ b/engines/hopkins/files.cpp
@@ -239,7 +239,7 @@ byte *FileManager::searchCat(const Common::String &file, CatMode mode, bool &fil
 		f.seek(_catalogPos);
 
 		byte *catData = _vm->_globals->allocMemory(_catalogSize);
-		if (catData == g_PTRNUL)
+		if (catData == NULL)
 			error("CHARGE_FICHIER");
 
 		readStream(f, catData, _catalogSize);
diff --git a/engines/hopkins/font.cpp b/engines/hopkins/font.cpp
index e25c11d70e..3277ebb8c2 100644
--- a/engines/hopkins/font.cpp
+++ b/engines/hopkins/font.cpp
@@ -59,7 +59,7 @@ void FontManager::loadZoneText() {
 }
 
 void FontManager::clearAll() {
-	_font = g_PTRNUL;
+	_font = NULL;
 	_fontFixedHeight = 0;
 	_fontFixedWidth = 0;
 
@@ -82,8 +82,8 @@ void FontManager::clearAll() {
 	for (int idx = 0; idx < 4048; idx++)
 		_index[idx] = 0;
 
-	_tempText = g_PTRNUL;
-	_zoneText = g_PTRNUL;
+	_tempText = NULL;
+	_zoneText = NULL;
 
 	_boxWidth = 240;
 }
@@ -214,7 +214,7 @@ void FontManager::box(int idx, int messageId, const Common::String &filename, in
 			f.seek(_index[messageId]);
 
 			_tempText = _vm->_globals->allocMemory(2058);
-			if (_tempText == g_PTRNUL)
+			if (_tempText == NULL)
 				error("Error allocating text");
 
 			Common::fill(&_tempText[0], &_tempText[2058], 0);
@@ -358,7 +358,7 @@ void FontManager::box(int idx, int messageId, const Common::String &filename, in
 		if (textType == 1 || textType == 3 || textType == 5 || textType == 6) {
 			int size = saveHeight * saveWidth;
 			byte *ptrd = _vm->_globals->allocMemory(size);
-			if (ptrd == g_PTRNUL)
+			if (ptrd == NULL)
 				error("Cutting a block for text box (%d)", size);
 
 			_vm->_graphicsManager->copySurfaceRect(_vm->_graphicsManager->_frontBuffer, ptrd, posX, posY, saveWidth, saveHeight);
@@ -389,7 +389,7 @@ void FontManager::box(int idx, int messageId, const Common::String &filename, in
 			_text[idx]._textBlock = _vm->_globals->freeMemory(_text[idx]._textBlock);
 			int blockSize = blockHeight * blockWidth;
 			byte *ptre = _vm->_globals->allocMemory(blockSize + 20);
-			if (ptre == g_PTRNUL)
+			if (ptre == NULL)
 				error("Cutting a block for text box (%d)", blockSize);
 
 			_text[idx]._textBlock = ptre;
diff --git a/engines/hopkins/globals.cpp b/engines/hopkins/globals.cpp
index c9bd925cae..c6dbb2d372 100644
--- a/engines/hopkins/globals.cpp
+++ b/engines/hopkins/globals.cpp
@@ -32,10 +32,6 @@
 
 namespace Hopkins {
 
-// Global null pointer. This is needed by the engine to recognise NULL pointers, since
-// there are places that differentiate between it and a 0 'error' value
-byte *g_PTRNUL;
-
 // Default data for the Hopkins array
 
 const int HOPKINS_PERSO_0[] = {
@@ -65,10 +61,6 @@ const int HOPKINS_PERSO_2[] = {
 Globals::Globals(HopkinsEngine *vm) {
 	_vm = vm;
 
-	// Set up the special g_PTRNUL variable
-	g_PTRNUL = (byte *)malloc(16);
-	strcpy((char *)g_PTRNUL, "POINTERNULL");
-
 	// Initialize array properties
 	for (int i = 0; i < 500; ++i)
 		_spriteSize[i] = 0;
@@ -113,11 +105,11 @@ Globals::Globals(HopkinsEngine *vm) {
 	_oceanDirection = DIR_NONE;
 
 	// Initialize pointers
-	_levelSpriteBuf = g_PTRNUL;
-	_saveData = (Savegame *)g_PTRNUL;
-	_answerBuffer = g_PTRNUL;
-	_characterSpriteBuf = g_PTRNUL;
-	_optionDialogSpr = g_PTRNUL;
+	_levelSpriteBuf = NULL;
+	_saveData = (Savegame *)NULL;
+	_answerBuffer = NULL;
+	_characterSpriteBuf = NULL;
+	_optionDialogSpr = NULL;
 
 	// Reset flags
 	_censorshipFl = false;
@@ -136,7 +128,7 @@ Globals::~Globals() {
 	freeMemory((byte *)_saveData);
 	freeMemory(_answerBuffer);
 	freeMemory(_characterSpriteBuf);
-	free(g_PTRNUL);
+	free(NULL);
 }
 
 void Globals::setConfig() {
@@ -178,9 +170,9 @@ void Globals::setConfig() {
 void Globals::clearAll() {
 	_vm->_fontManager->clearAll();
 	_vm->_dialogsManager->clearAll();
-	_answerBuffer = g_PTRNUL;
-	_levelSpriteBuf = g_PTRNUL;
-	_saveData = (Savegame *)g_PTRNUL;
+	_answerBuffer = NULL;
+	_levelSpriteBuf = NULL;
+	_saveData = (Savegame *)NULL;
 	_vm->_objectsManager->_curObjectIndex = 0;
 
 	_vm->_linesManager->clearAll();
@@ -210,14 +202,14 @@ void Globals::loadCharacterData() {
 byte *Globals::allocMemory(int count) {
 	byte *result = (byte *)malloc(count);
 	if (!result)
-		result = g_PTRNUL;
+		result = NULL;
 	return result;
 }
 
 byte *Globals::freeMemory(byte *p) {
-	if (p != g_PTRNUL)
+	if (p != NULL)
 		free(p);
-	return g_PTRNUL;
+	return NULL;
 }
 
 } // End of namespace Hopkins
diff --git a/engines/hopkins/globals.h b/engines/hopkins/globals.h
index 71bc3f0ab4..62cc5bb9e0 100644
--- a/engines/hopkins/globals.h
+++ b/engines/hopkins/globals.h
@@ -220,9 +220,6 @@ public:
 	int _curRoomNum;
 };
 
-// Global null pointer
-extern byte *g_PTRNUL;
-
 } // End of namespace Hopkins
 
 #endif /* HOPKINS_GLOBALS_H */
diff --git a/engines/hopkins/graphics.cpp b/engines/hopkins/graphics.cpp
index a903462ecb..7a965146e7 100644
--- a/engines/hopkins/graphics.cpp
+++ b/engines/hopkins/graphics.cpp
@@ -42,17 +42,17 @@ GraphicsManager::GraphicsManager(HopkinsEngine *vm) {
 	_initGraphicsFl = false;
 	_screenWidth = _screenHeight = 0;
 	_screenLineSize = 0;
-	PAL_PIXELS = g_PTRNUL;
+	PAL_PIXELS = NULL;
 	_lineNbr = 0;
 	_videoPtr = NULL;
 	_scrollOffset = 0;
 	_scrollPosX = 0;
 	_largeScreenFl = false;
 	_oldScrollPosX = 0;
-	_backBuffer = g_PTRNUL;
-	_frontBuffer = g_PTRNUL;
-	_screenBuffer = g_PTRNUL;
-	_backupScreen = g_PTRNUL;
+	_backBuffer = NULL;
+	_frontBuffer = NULL;
+	_screenBuffer = NULL;
+	_backupScreen = NULL;
 	_showDirtyRects = false;
 
 	_lineNbr2 = 0;
@@ -1840,7 +1840,7 @@ void GraphicsManager::drawVerticalLine(byte *surface, int xp, int yp, int height
  */
 void GraphicsManager::backupScreen() {
 	// Allocate a new data block for the screen, if necessary
-	if (_vm->_graphicsManager->_backupScreen == g_PTRNUL)
+	if (_vm->_graphicsManager->_backupScreen == NULL)
 		_vm->_graphicsManager->_backupScreen = _vm->_globals->allocMemory(SCREEN_WIDTH * 2 * SCREEN_HEIGHT);
 
 	// Backup the screen
@@ -1852,13 +1852,13 @@ void GraphicsManager::backupScreen() {
  * Restore a previously backed up screen
  */
 void GraphicsManager::restoreScreen() {
-	assert(_vm->_graphicsManager->_backupScreen != g_PTRNUL);
+	assert(_vm->_graphicsManager->_backupScreen != NULL);
 
 	// Restore the screen and free the buffer
 	Common::copy(_vm->_graphicsManager->_backupScreen, _vm->_graphicsManager->_backupScreen +
 		SCREEN_WIDTH * 2 * SCREEN_HEIGHT, _vm->_graphicsManager->_backBuffer);
 	_vm->_globals->freeMemory(_vm->_graphicsManager->_backupScreen);
-	_backupScreen = g_PTRNUL;
+	_backupScreen = NULL;
 }
 
 } // End of namespace Hopkins
diff --git a/engines/hopkins/hopkins.cpp b/engines/hopkins/hopkins.cpp
index 66e01b0f9c..e60efdcc25 100644
--- a/engines/hopkins/hopkins.cpp
+++ b/engines/hopkins/hopkins.cpp
@@ -1193,7 +1193,7 @@ bool HopkinsEngine::runFull() {
 			_objectsManager->_forestFl = true;
 			Common::String im = Common::String::format("IM%d", _globals->_exitId);
 			_soundManager->playSound(13);
-			if (_objectsManager->_forestSprite == g_PTRNUL) {
+			if (_objectsManager->_forestSprite == NULL) {
 				_objectsManager->_forestSprite = _objectsManager->loadSprite("HOPDEG.SPR");
 				_soundManager->loadSample(1, "SOUND41.WAV");
 			}
@@ -2097,7 +2097,7 @@ void HopkinsEngine::playEnding() {
 	_globals->_cityMapEnabledFl = false;
 	_globals->_eventMode = EVENTMODE_IGNORE;
 	_soundManager->playSound(26);
-	_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_linesManager->_route = (RouteItem *)NULL;
 	_globals->_freezeCharacterFl = true;
 	_globals->_exitId = 0;
 	_soundManager->loadSample(1, "SOUND90.WAV");
@@ -2830,7 +2830,7 @@ void HopkinsEngine::handleOceanMaze(int16 curExitId, Common::String backgroundFi
 	_graphicsManager->SETCOLOR3(251, 100, 100, 100);
 	_graphicsManager->SETCOLOR3(254, 0, 0, 0);
 	_objectsManager->animateSprite(0);
-	_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_linesManager->_route = (RouteItem *)NULL;
 	_eventsManager->mouseOn();
 	_eventsManager->changeMouseCursor(4);
 
diff --git a/engines/hopkins/lines.cpp b/engines/hopkins/lines.cpp
index d74bc8f3a0..16a0a9c029 100644
--- a/engines/hopkins/lines.cpp
+++ b/engines/hopkins/lines.cpp
@@ -67,13 +67,13 @@ LinesManager::LinesManager(HopkinsEngine *vm) {
 	_lastLine = 0;
 	_maxLineIdx = 0;
 	_pathFindingMaxDepth = 0;
-	_testRoute0 = (RouteItem *)g_PTRNUL;
-	_testRoute1 = (RouteItem *)g_PTRNUL;
-	_testRoute2 = (RouteItem *)g_PTRNUL;
-	_lineBuf = (int16 *)g_PTRNUL;
-	_route = (RouteItem *)g_PTRNUL;
+	_testRoute0 = (RouteItem *)NULL;
+	_testRoute1 = (RouteItem *)NULL;
+	_testRoute2 = (RouteItem *)NULL;
+	_lineBuf = (int16 *)NULL;
+	_route = (RouteItem *)NULL;
 	_currentSegmentId = 0;
-	_largeBuf = g_PTRNUL;
+	_largeBuf = NULL;
 	_zoneSkipCount = 0;
 	_hotspotTextColor = 0;
 	_forceHideText = false;
@@ -89,11 +89,11 @@ LinesManager::LinesManager(HopkinsEngine *vm) {
 
 LinesManager::~LinesManager() {
 	_vm->_globals->freeMemory(_largeBuf);
-	if (_testRoute0 != (RouteItem *)g_PTRNUL)
+	if (_testRoute0 != (RouteItem *)NULL)
 		delete[] _testRoute0;
-	if (_testRoute1 != (RouteItem *)g_PTRNUL)
+	if (_testRoute1 != (RouteItem *)NULL)
 		delete[] _testRoute1;
-	if (_testRoute2 != (RouteItem *)g_PTRNUL)
+	if (_testRoute2 != (RouteItem *)NULL)
 		delete[] _testRoute2;
 }
 
@@ -220,7 +220,7 @@ void LinesManager::addZoneLine(int idx, int fromX, int fromY, int destX, int des
 			maxDist += distX;
 
 		zoneData = (int16 *)_vm->_globals->allocMemory(2 * sizeof(int16) * maxDist + (4 * sizeof(int16)));
-		assert(zoneData != (int16 *)g_PTRNUL);
+		assert(zoneData != (int16 *)NULL);
 
 		_zoneLine[idx]._zoneData = zoneData;
 
@@ -265,7 +265,7 @@ void LinesManager::addLine(int lineIdx, Directions direction, int fromX, int fro
 		maxDist = distX;
 
 	byte *zoneData = _vm->_globals->allocMemory(4 * maxDist + 8);
-	assert (zoneData != g_PTRNUL);
+	assert (zoneData != NULL);
 
 	Common::fill(zoneData, zoneData + 4 * maxDist + 8, 0);
 	_lineItem[lineIdx]._lineData = (int16 *)zoneData;
@@ -379,7 +379,7 @@ bool LinesManager::checkCollisionLine(int xp, int yp, int *foundDataIdx, int *fo
 	for (int curLineIdx = startLineIdx; curLineIdx <= endLineIdx; curLineIdx++) {
 		lineData = _lineItem[curLineIdx]._lineData;
 
-		if (lineData == (int16 *)g_PTRNUL)
+		if (lineData == (int16 *)NULL)
 			continue;
 
 		bool collisionFl = true;
@@ -443,6 +443,8 @@ void LinesManager::initRoute() {
 			error("ERROR - LAST LINE NOT FOUND");
 
 		int16 *nextLineData = _lineItem[lineIdx + 1]._lineData;
+		if (!nextLineData)
+			break;
 		if (nextLineData[0] != curLineX && nextLineData[1] != curLineY)
 			break;
 		++lineIdx;
@@ -791,14 +793,14 @@ int LinesManager::computeRouteIdx(int lineIdx, int dataIdx, int fromX, int fromY
 		int endLineIdx = 2 * _lineItem[startLineIdx - 1]._lineDataEndIdx;
 
 		int16 *lineData = _lineItem[startLineIdx - 1]._lineData;
-		if (lineData == (int16 *)g_PTRNUL)
+		if (lineData == (int16 *)NULL)
 			break;
 		while (lineData[endLineIdx - 2] != lineX || lineY != lineData[endLineIdx - 1]) {
 			--curLineIdx;
 			if (_lastLine - 1 != curLineIdx) {
 				endLineIdx = 2 * _lineItem[curLineIdx]._lineDataEndIdx;
 				lineData = _lineItem[curLineIdx]._lineData;
-				if (lineData != (int16 *)g_PTRNUL)
+				if (lineData != (int16 *)NULL)
 					continue;
 			}
 			loopCond = true;
@@ -822,7 +824,7 @@ int LinesManager::computeRouteIdx(int lineIdx, int dataIdx, int fromX, int fromY
 		int curLineIdx = endLineIdx + 1;
 		int nextLineDataEndIdx = 2 * _lineItem[curLineIdx]._lineDataEndIdx;
 		int16 *lineData = _lineItem[curLineIdx]._lineData;
-		if (lineData == (int16 *)g_PTRNUL)
+		if (lineData == (int16 *)NULL)
 			break;
 		for (;;) {
 			curLineDataEndIdx = nextLineDataEndIdx;
@@ -833,7 +835,7 @@ int LinesManager::computeRouteIdx(int lineIdx, int dataIdx, int fromX, int fromY
 			if (curLineIdx != _linesNumb + 1) {
 				nextLineDataEndIdx = 2 * _lineItem[curLineIdx]._lineDataEndIdx;
 				lineData = _lineItem[curLineIdx]._lineData;
-				if (lineData != (int16 *)g_PTRNUL)
+				if (lineData != (int16 *)NULL)
 					continue;
 			}
 			loopCond = true;
@@ -893,7 +895,7 @@ int LinesManager::computeRouteIdx(int lineIdx, int dataIdx, int fromX, int fromY
 	int minLineY = 0;
 	for (int i = startLineIdx; i <= endLineIdx; ++i) {
 		int16 *lineData = _lineItem[i]._lineData;
-		if (lineData == (int16 *)g_PTRNUL)
+		if (lineData == (int16 *)NULL)
 			error("error in genial routine");
 		if (i == startLineIdx) {
 			minLineY = MIN(lineData[1], lineData[2 * _lineItem[i]._lineDataEndIdx - 1]);
@@ -1094,13 +1096,13 @@ RouteItem *LinesManager::findRoute(int fromX, int fromY, int destX, int destY) {
 	if (!_vm->_globals->_checkDistanceFl) {
 		if (abs(fromX - _oldRouteFromX) <= 4 && abs(fromY - _oldRouteFromY) <= 4 &&
 		    abs(_oldRouteDestX - destX) <= 4 && abs(_oldRouteDestY - clipDestY) <= 4)
-			return (RouteItem *)g_PTRNUL;
+			return (RouteItem *)NULL;
 
 		if (abs(fromX - destX) <= 4 && abs(fromY - clipDestY) <= 4)
-			return (RouteItem *)g_PTRNUL;
+			return (RouteItem *)NULL;
 
 		if (_oldZoneNum > 0 && _vm->_objectsManager->_zoneNum > 0 && _oldZoneNum == _vm->_objectsManager->_zoneNum)
-			return (RouteItem *)g_PTRNUL;
+			return (RouteItem *)NULL;
 	}
 	_vm->_globals->_checkDistanceFl = false;
 	_oldZoneNum = _vm->_objectsManager->_zoneNum;
@@ -1120,7 +1122,7 @@ RouteItem *LinesManager::findRoute(int fromX, int fromY, int destX, int destY) {
 		clipDestY = _vm->_globals->_characterMaxPosY;
 
 	if (abs(fromX - clipDestX) <= 3 && abs(fromY - clipDestY) <= 3)
-		return (RouteItem *)g_PTRNUL;
+		return (RouteItem *)NULL;
 
 	for (int i = 0; i <= 8; ++i) {
 		collLineIdxArr[i] = -1;
@@ -1199,7 +1201,7 @@ RouteItem *LinesManager::findRoute(int fromX, int fromY, int destX, int destY) {
 	if (collLineIdxArr[DIR_LEFT] < 0)
 		deltaArr[DIR_LEFT] = INVALID_LINE_VALUE;
 	if (collLineIdxArr[DIR_UP] == -1 && collLineIdxArr[DIR_RIGHT] == -1 && collLineIdxArr[DIR_DOWN] == -1 && collLineIdxArr[DIR_LEFT] == -1)
-		return (RouteItem *)g_PTRNUL;
+		return (RouteItem *)NULL;
 
 	if (collLineIdxArr[DIR_DOWN] != -1 && deltaArr[DIR_UP] >= deltaArr[DIR_DOWN] && deltaArr[DIR_RIGHT] >= deltaArr[DIR_DOWN] && deltaArr[DIR_LEFT] >= deltaArr[DIR_DOWN]) {
 		curLineIdx = collLineIdxArr[DIR_DOWN];
@@ -2155,7 +2157,7 @@ RouteItem *LinesManager::cityMapCarRoute(int x1, int y1, int x2, int y2) {
 		_bestRoute[superRouteIdx].invalidate();
 		result = &_bestRoute[0];
 	} else {
-		result = (RouteItem *)g_PTRNUL;
+		result = (RouteItem *)NULL;
 	}
 	return result;
 }
@@ -2645,7 +2647,7 @@ int LinesManager::checkCollision(int xp, int yp) {
 		do {
 			LigneZoneItem *curZoneLine = &_zoneLine[curZoneLineIdx];
 			int16 *dataP = curZoneLine->_zoneData;
-			if (dataP != (int16 *)g_PTRNUL) {
+			if (dataP != (int16 *)NULL) {
 				int count = curZoneLine->_count;
 				int startX = dataP[0];
 				int startY = dataP[1];
@@ -2691,7 +2693,7 @@ void LinesManager::initSquareZones() {
 
 	for (int idx = 0; idx < MAX_LINES; ++idx) {
 		int16 *dataP = _zoneLine[idx]._zoneData;
-		if (dataP == (int16 *)g_PTRNUL)
+		if (dataP == (int16 *)NULL)
 			continue;
 
 		SquareZoneItem *curZone = &_squareZone[_zoneLine[idx]._bobZoneIdx];
@@ -2725,22 +2727,22 @@ void LinesManager::clearAll() {
 		_zone[idx]._spriteIndex = 0;
 	}
 
-	_testRoute0 = (RouteItem *)g_PTRNUL;
-	_testRoute1 = (RouteItem *)g_PTRNUL;
-	_testRoute2 = (RouteItem *)g_PTRNUL;
-	_lineBuf = (int16 *)g_PTRNUL;
-	_route = (RouteItem *)g_PTRNUL;
+	_testRoute0 = (RouteItem *)NULL;
+	_testRoute1 = (RouteItem *)NULL;
+	_testRoute2 = (RouteItem *)NULL;
+	_lineBuf = (int16 *)NULL;
+	_route = (RouteItem *)NULL;
 
 	for (int idx = 0; idx < MAX_LINES; ++idx) {
 		_lineItem[idx]._lineDataEndIdx = 0;
 		_lineItem[idx]._direction = DIR_NONE;
 		_lineItem[idx]._directionRouteInc = DIR_NONE;
 		_lineItem[idx]._directionRouteDec = DIR_NONE;
-		_lineItem[idx]._lineData = (int16 *)g_PTRNUL;
+		_lineItem[idx]._lineData = (int16 *)NULL;
 
 		_zoneLine[idx]._count = 0;
 		_zoneLine[idx]._bobZoneIdx = 0;
-		_zoneLine[idx]._zoneData = (int16 *)g_PTRNUL;
+		_zoneLine[idx]._zoneData = (int16 *)NULL;
 	}
 
 	for (int idx = 0; idx < 100; ++idx)
@@ -2750,11 +2752,11 @@ void LinesManager::clearAll() {
 	_testRoute1 = new RouteItem[8334];
 	_testRoute2 = new RouteItem[8334];
 	if (!_testRoute0)
-		_testRoute0 = (RouteItem*)g_PTRNUL;
+		_testRoute0 = (RouteItem*)NULL;
 	if (!_testRoute1)
-		_testRoute1 = (RouteItem*)g_PTRNUL;
+		_testRoute1 = (RouteItem*)NULL;
 	if (!_testRoute2)
-		_testRoute2 = (RouteItem*)g_PTRNUL;
+		_testRoute2 = (RouteItem*)NULL;
 	
 	_largeBuf = _vm->_globals->allocMemory(10000);
 	_lineBuf = (int16 *)(_largeBuf);
@@ -2780,7 +2782,7 @@ void LinesManager::resetLines() {
 	for (int idx = 0; idx < MAX_LINES; ++idx) {
 		removeLine(idx);
 		_lineItem[idx]._lineDataEndIdx = 0;
-		_lineItem[idx]._lineData = (int16 *)g_PTRNUL;
+		_lineItem[idx]._lineData = (int16 *)NULL;
 	}
 }
 
@@ -2845,7 +2847,7 @@ void LinesManager::checkZone() {
 	if (_zoneSkipCount <= 1)
 		return;
 
-	if (_vm->_globals->_freezeCharacterFl || (_route == (RouteItem *)g_PTRNUL) || _zoneSkipCount > 4) {
+	if (_vm->_globals->_freezeCharacterFl || (_route == (RouteItem *)NULL) || _zoneSkipCount > 4) {
 		_zoneSkipCount = 0;
 		int zoneId;
 		if (_oldMouseX != mouseX || _oldMouseY != oldMouseY) {
diff --git a/engines/hopkins/menu.cpp b/engines/hopkins/menu.cpp
index 6a5cbd2421..8a4c9c466c 100644
--- a/engines/hopkins/menu.cpp
+++ b/engines/hopkins/menu.cpp
@@ -44,7 +44,7 @@ MenuManager::MenuManager(HopkinsEngine *vm) {
 }
 
 int MenuManager::menu() {
-	byte *spriteData = g_PTRNUL;
+	byte *spriteData = NULL;
 	MenuSelection menuIndex;
 	Common::Point mousePos;
 	signed int result;
diff --git a/engines/hopkins/objects.cpp b/engines/hopkins/objects.cpp
index 6e6d539ea2..5b9c84fe24 100644
--- a/engines/hopkins/objects.cpp
+++ b/engines/hopkins/objects.cpp
@@ -60,7 +60,7 @@ ObjectsManager::ObjectsManager(HopkinsEngine *vm) {
 		Common::fill((byte *)&_hidingItem[i], (byte *)&_hidingItem[i] + sizeof(HidingItem), 0);
 
 	for (int i = 0; i < 6; ++i)
-		_hidingItemData[i] = g_PTRNUL;
+		_hidingItemData[i] = NULL;
 
 	for (int i = 0; i < 6; ++i)
 		Common::fill((byte *)&Liste[i], (byte *)&Liste[i] + sizeof(ListeItem), 0);
@@ -78,10 +78,10 @@ ObjectsManager::ObjectsManager(HopkinsEngine *vm) {
 	_oldInventoryPosX = _oldInventoryPosY = 0;
 	_oldCharacterPosX = _oldCharacterPosY = 0;
 	_eraseVisibleCounter = 0;
-	_saveLoadSprite = g_PTRNUL;
-	_saveLoadSprite2 = g_PTRNUL;
-	_spritePtr = g_PTRNUL;
-	_oldSpriteData = g_PTRNUL;
+	_saveLoadSprite = NULL;
+	_saveLoadSprite2 = NULL;
+	_spritePtr = NULL;
+	_oldSpriteData = NULL;
 	_saveLoadFl = false;
 	_visibleFl = false;
 	_zoneNum = 0;
@@ -101,10 +101,10 @@ ObjectsManager::ObjectsManager(HopkinsEngine *vm) {
 	_curObjectIndex = 0;
 	_forestFl = false;
 	_mapCarPosX = _mapCarPosY = 0;
-	_forestSprite = g_PTRNUL;
-	_gestureBuf = g_PTRNUL;
+	_forestSprite = NULL;
+	_gestureBuf = NULL;
 	_curGestureFile = 0;
-	_headSprites = g_PTRNUL;
+	_headSprites = NULL;
 	_homeRateCounter = 0;
 	_lastDirection = DIR_NONE;
 	_oldDirection = DIR_NONE;
@@ -112,7 +112,7 @@ ObjectsManager::ObjectsManager(HopkinsEngine *vm) {
 	_objectWidth = _objectHeight = 0;
 	_hidingActiveFl = false;
 	_curObjectFileNum = 0;
-	_objectDataBuf = g_PTRNUL;
+	_objectDataBuf = NULL;
 	_charactersEnabledFl = false;
 	_refreshBobMode10Fl = false;
 }
@@ -170,7 +170,7 @@ void ObjectsManager::resetHidingItems() {
 
 	for (int idx = 0; idx <= 20; ++idx) {
 		HidingItem *hid = &_hidingItem[idx];
-		hid->_spriteData = g_PTRNUL;
+		hid->_spriteData = NULL;
 		hid->_x = 0;
 		hid->_y = 0;
 		hid->_spriteIndex = 0;
@@ -193,7 +193,7 @@ void ObjectsManager::changeObject(int objIndex) {
 }
 
 byte *ObjectsManager::loadObjectFromFile(int objIndex, bool mode) {
-	byte *dataP = g_PTRNUL;
+	byte *dataP = NULL;
 	int objectFileNum = _objectAuthIcons[objIndex]._objectFileNum;
 	int idx = _objectAuthIcons[objIndex]._idx;
 
@@ -201,7 +201,7 @@ byte *ObjectsManager::loadObjectFromFile(int objIndex, bool mode) {
 		++idx;
 
 	if (objectFileNum != _curObjectFileNum) {
-		if (_objectDataBuf != g_PTRNUL)
+		if (_objectDataBuf != NULL)
 			removeObjectDataBuf();
 		if (objectFileNum == 1) {
 			_objectDataBuf = loadSprite("OBJET1.SPR");
@@ -219,7 +219,7 @@ byte *ObjectsManager::loadObjectFromFile(int objIndex, bool mode) {
 		dataP = _vm->_eventsManager->_objectBuf;
 	} else { 
 		dataP = _vm->_globals->allocMemory(height * width);
-		if (dataP == g_PTRNUL)
+		if (dataP == NULL)
 			error("CAPTURE_OBJET");
 
 		capture_mem_sprite(_objectDataBuf, dataP, idx);
@@ -572,7 +572,7 @@ void ObjectsManager::resetBob(int idx) {
 	ListeItem &item = Liste2[idx];
 
 	bob._bobMode = 0;
-	bob._spriteData = g_PTRNUL;
+	bob._spriteData = NULL;
 	bob._xp = 0;
 	bob._yp = 0;
 	bob._frameIndex = 0;
@@ -580,7 +580,7 @@ void ObjectsManager::resetBob(int idx) {
 	bob._moveChange1 = 0;
 	bob._moveChange2 = 0;
 	bob._disabledAnimationFl = false;
-	bob._animData = g_PTRNUL;
+	bob._animData = NULL;
 	bob._bobMode10 = false;
 	bob._bobModeChange = 0;
 	bob._modeChangeCtr = 0;
@@ -1000,7 +1000,7 @@ void ObjectsManager::displayBobAnim() {
 			continue;
 
 		_bob[idx]._bobMode10 = false;
-		if (_bob[idx]._animData == g_PTRNUL || _bob[idx]._disabledAnimationFl || _bob[idx]._modeChangeCtr == 0 || _bob[idx]._modeChangeCtr < -1) {
+		if (_bob[idx]._animData == NULL || _bob[idx]._disabledAnimationFl || _bob[idx]._modeChangeCtr == 0 || _bob[idx]._modeChangeCtr < -1) {
 			if (_bob[idx]._bobModeChange == 1 || _bob[idx]._bobModeChange == 2)
 				_bob[idx]._bobMode10 = true;
 			continue;
@@ -1155,14 +1155,14 @@ void ObjectsManager::displayVBob() {
 			vbob->_surface = _vm->_globals->freeMemory(vbob->_surface);
 
 			vbob->_displayMode = 0;
-			vbob->_spriteData = g_PTRNUL;
+			vbob->_spriteData = NULL;
 			vbob->_xp = 0;
 			vbob->_yp = 0;
 			vbob->_oldX = 0;
 			vbob->_oldY = 0;
 			vbob->_frameIndex = 0;
 			vbob->_oldFrameIndex = 0;
-			vbob->_oldSpriteData = g_PTRNUL;
+			vbob->_oldSpriteData = NULL;
 		}
 
 		if (vbob->_displayMode == 3) {
@@ -1240,7 +1240,7 @@ int ObjectsManager::getSpriteY(int idx) {
  */
 void ObjectsManager::clearSprite() {
 	for (int idx = 0; idx < MAX_SPRITE; idx++) {
-		_sprite[idx]._spriteData = g_PTRNUL;
+		_sprite[idx]._spriteData = NULL;
 		_sprite[idx]._animationType = 0;
 	}
 
@@ -1327,7 +1327,7 @@ void ObjectsManager::setFlipSprite(int idx, bool flipFl) {
 }
 
 void ObjectsManager::GOHOME() {
-	if (_vm->_linesManager->_route == (RouteItem *)g_PTRNUL)
+	if (_vm->_linesManager->_route == (RouteItem *)NULL)
 		return;
 
 	if (_homeRateCounter > 1) {
@@ -1364,11 +1364,11 @@ void ObjectsManager::GOHOME() {
 				zoneId = _vm->_globals->_saveData->_data[svLastZoneNum];
 			else
 				zoneId = _zoneNum;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			computeAndSetSpriteSize();
 			setFlipSprite(0, false);
 			_homeRateCounter = 0;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_oldDirection = DIR_NONE;
 			if (zoneId > 0) {
 				if (_vm->_linesManager->_zone[zoneId]._destX && _vm->_linesManager->_zone[zoneId]._destY && _vm->_linesManager->_zone[zoneId]._destY != 31) {
@@ -1584,7 +1584,7 @@ void ObjectsManager::GOHOME() {
 				zoneId = _zoneNum;
 			setSpriteIndex(0, _oldDirection + 59);
 			_vm->_globals->_actionDirection = DIR_NONE;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			computeAndSetSpriteSize();
 			setFlipSprite(0, false);
 			_homeRateCounter = 0;
@@ -1644,7 +1644,7 @@ void ObjectsManager::GOHOME() {
 }
 
 void ObjectsManager::GOHOME2() {
-	if (_vm->_linesManager->_route == (RouteItem *)g_PTRNUL)
+	if (_vm->_linesManager->_route == (RouteItem *)NULL)
 		return;
 
 	int realSpeed = 2;
@@ -1707,7 +1707,7 @@ void ObjectsManager::GOHOME2() {
 		break;
 	}
 
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 }
 
 /**
@@ -1795,7 +1795,7 @@ void ObjectsManager::handleCityMap() {
 	_vm->_globals->_cityMapEnabledFl = true;
 	_vm->_graphicsManager->_noFadingFl = false;
 	_vm->_globals->_freezeCharacterFl = false;
-	_spritePtr = g_PTRNUL;
+	_spritePtr = NULL;
 	_vm->_globals->_exitId = 0;
 	_vm->_globals->_checkDistanceFl = true;
 	_vm->_soundManager->playSound(31);
@@ -1824,7 +1824,7 @@ void ObjectsManager::handleCityMap() {
 	_vm->_graphicsManager->scrollScreen(getSpriteX(0) - 320);
 	_vm->_graphicsManager->_scrollOffset = getSpriteX(0) - 320;
 	animateSprite(0);
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 	_vm->_graphicsManager->SETCOLOR3(252, 100, 100, 100);
 	_vm->_graphicsManager->SETCOLOR3(253, 100, 100, 100);
 	_vm->_graphicsManager->SETCOLOR3(251, 100, 100, 100);
@@ -1866,7 +1866,7 @@ void ObjectsManager::handleCityMap() {
 		_vm->_linesManager->checkZone();
 		GOHOME2();
 
-		if (_vm->_linesManager->_route == (RouteItem *)g_PTRNUL && _vm->_globals->_actionMoveTo)
+		if (_vm->_linesManager->_route == (RouteItem *)NULL && _vm->_globals->_actionMoveTo)
 			PARADISE();
 		_vm->_eventsManager->refreshScreenAndEvents();
 
@@ -1960,25 +1960,25 @@ void ObjectsManager::handleLeftButton() {
 	}
 	_vm->_globals->_actionMoveTo = false;
 	RouteItem *oldRoute = _vm->_linesManager->_route;
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 	if (_forestFl && _zoneNum >= 20 && _zoneNum <= 23) {
 		if (getSpriteY(0) > 374 && getSpriteY(0) <= 410) {
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			setSpriteIndex(0, _oldDirectionSpriteIdx);
 			_vm->_globals->_actionDirection = DIR_NONE;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			computeAndSetSpriteSize();
 			setFlipSprite(0, false);
 			_homeRateCounter = 0;
 			_oldDirection = DIR_NONE;
 		} else {
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(getSpriteX(0), getSpriteY(0), getSpriteX(0), 390);
-			if (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL)
+			if (_vm->_linesManager->_route != (RouteItem *)NULL)
 				_vm->_linesManager->optimizeRoute(_vm->_linesManager->_route);
 			_oldCharacterPosX = getSpriteX(0);
 			_oldCharacterPosY = getSpriteY(0);
 			_homeRateCounter = 0;
-			if (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL || oldRoute == _vm->_linesManager->_route) {
+			if (_vm->_linesManager->_route != (RouteItem *)NULL || oldRoute == _vm->_linesManager->_route) {
 				_oldDirection = DIR_NONE;
 			} else {
 				_vm->_linesManager->_route = oldRoute;
@@ -1987,12 +1987,12 @@ void ObjectsManager::handleLeftButton() {
 	} else {
 		if (!_vm->_globals->_freezeCharacterFl && !_vm->_globals->_cityMapEnabledFl) {
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(getSpriteX(0), getSpriteY(0), destX, destY);
-			if (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL)
+			if (_vm->_linesManager->_route != (RouteItem *)NULL)
 				_vm->_linesManager->optimizeRoute(_vm->_linesManager->_route);
 			_oldCharacterPosX = getSpriteX(0);
 			_oldCharacterPosY = getSpriteY(0);
 			_homeRateCounter = 0;
-			if (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL || oldRoute == _vm->_linesManager->_route)
+			if (_vm->_linesManager->_route != (RouteItem *)NULL || oldRoute == _vm->_linesManager->_route)
 				_oldDirection = DIR_NONE;
 			else
 				_vm->_linesManager->_route = oldRoute;
@@ -2020,7 +2020,7 @@ void ObjectsManager::handleLeftButton() {
 				&& _curObjectIndex == 20 && _zoneNum == 12
 				&& _vm->_eventsManager->_mouseCursorId == 23) {
 		// Special case for throwing darts at the switch in Purgatory - the player shouldn't move
-		_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+		_vm->_linesManager->_route = (RouteItem *)NULL;
 		getSpriteX(0);
 		getSpriteY(0);
 	}
@@ -2137,7 +2137,7 @@ void ObjectsManager::clearScreen() {
 	_forceZoneFl = true;
 	_vm->_linesManager->resetLinesNumb();
 	_vm->_linesManager->resetLastLine();
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 	_vm->_globals->_answerBuffer = _vm->_globals->freeMemory(_vm->_globals->_answerBuffer);
 	_vm->_globals->_levelSpriteBuf = _vm->_globals->freeMemory(_vm->_globals->_levelSpriteBuf);
 	_vm->_eventsManager->_startPos.x = 0;
@@ -2147,7 +2147,7 @@ void ObjectsManager::clearScreen() {
 	_vm->_globals->_actionMoveTo = false;
 	_forceZoneFl = true;
 	_changeVerbFl = false;
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 	_oldDirection = DIR_NONE;
 	_vm->_graphicsManager->resetDirtyRects();
 }
@@ -2164,7 +2164,7 @@ void ObjectsManager::changeCharacterHead(PlayerCharacter oldCharacter, PlayerCha
 	_vm->_graphicsManager->copySurface(_vm->_graphicsManager->_backBuffer, 532, 25, 65, 40, _vm->_graphicsManager->_frontBuffer, 532, 25);
 	_vm->_graphicsManager->addDirtyRect(532, 25, 597, 65);
 	_vm->_globals->_checkDistanceFl = true;
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 
 	if (oldCharacter == CHARACTER_SAMANTHA && newCharacter == CHARACTER_HOPKINS
 		&& _vm->_globals->_saveData->_realHopkins._location == _vm->_globals->_screenId) {
@@ -2606,7 +2606,7 @@ void ObjectsManager::loadObjectIniFile() {
 	data = _vm->_fileManager->searchCat(file, RES_INI, fileFoundFl);
 	if (!fileFoundFl) {
 		data = _vm->_fileManager->loadFile(file);
-		if (data == g_PTRNUL)
+		if (data == NULL)
 			error("INI file %s not found", file.c_str());
 	}
 
@@ -3111,7 +3111,7 @@ void ObjectsManager::loadLinkFile(const Common::String &file, bool skipDetails)
 
 		nbytes = f.size();
 		ptr = _vm->_globals->allocMemory(nbytes);
-		if (ptr == g_PTRNUL)
+		if (ptr == NULL)
 			error("INILINK");
 		_vm->_fileManager->readStream(f, ptr, nbytes);
 		f.close();
@@ -3725,7 +3725,7 @@ void ObjectsManager::PERSONAGE(const Common::String &backgroundFile, const Commo
 	_vm->_globals->_cityMapEnabledFl = false;
 	_vm->_globals->_eventMode = EVENTMODE_IGNORE;
 	_vm->_soundManager->playSound(soundNum);
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 	_vm->_globals->_freezeCharacterFl = true;
 	_vm->_globals->_exitId = 0;
 	if (!backgroundFile.empty())
@@ -3745,7 +3745,7 @@ void ObjectsManager::PERSONAGE(const Common::String &backgroundFile, const Commo
 	if (_vm->_globals->_screenId == 61) {
 		addStaticSprite(_vm->_globals->_characterSpriteBuf, Common::Point(330, 418), 0, 60, 0, false, 34, 190);
 		animateSprite(0);
-		_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+		_vm->_linesManager->_route = (RouteItem *)NULL;
 		computeAndSetSpriteSize();
 	}
 	_vm->_graphicsManager->SETCOLOR3(252, 100, 100, 100);
@@ -3763,13 +3763,13 @@ void ObjectsManager::PERSONAGE(const Common::String &backgroundFile, const Commo
 		_oldCharacterPosX = getSpriteX(0);
 		_oldDirection = DIR_NONE;
 		_homeRateCounter = 0;
-		_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+		_vm->_linesManager->_route = (RouteItem *)NULL;
 		_vm->_linesManager->_route = _vm->_linesManager->findRoute(getSpriteX(0), getSpriteY(0), 330, 345);
 		_vm->_globals->_checkDistanceFl = true;
 		do {
 			GOHOME();
 			_vm->_eventsManager->refreshScreenAndEvents();
-		} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+		} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 		setSpriteIndex(0, 64);
 	}
 	do {
@@ -3871,7 +3871,7 @@ void ObjectsManager::PERSONAGE2(const Common::String &backgroundFile, const Comm
 	computeAndSetSpriteSize();
 	animateSprite(0);
 	enableHidingBehavior();
-	_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+	_vm->_linesManager->_route = (RouteItem *)NULL;
 	computeAndSetSpriteSize();
 	sceneSpecialIni();
 	_vm->_eventsManager->_mouseSpriteId = 4;
@@ -3902,7 +3902,7 @@ void ObjectsManager::PERSONAGE2(const Common::String &backgroundFile, const Comm
 					int yp = _vm->_eventsManager->getMouseY();
 
 					if ((xCheck == xp) && (yCheck == yp)) {
-						_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+						_vm->_linesManager->_route = (RouteItem *)NULL;
 						PARADISE();
 						if (_vm->_globals->_exitId)
 							breakFlag = true;
@@ -3918,8 +3918,8 @@ void ObjectsManager::PERSONAGE2(const Common::String &backgroundFile, const Comm
 		if (!_vm->_globals->_exitId) {
 			_vm->_dialogsManager->testDialogOpening();
 			_vm->_linesManager->checkZone();
-			if (_vm->_linesManager->_route == (RouteItem *)g_PTRNUL
-					|| (GOHOME(), _vm->_linesManager->_route == (RouteItem *)g_PTRNUL)) {
+			if (_vm->_linesManager->_route == (RouteItem *)NULL
+					|| (GOHOME(), _vm->_linesManager->_route == (RouteItem *)NULL)) {
 				if (_vm->_globals->_actionMoveTo)
 					PARADISE();
 			}
@@ -3979,7 +3979,7 @@ void ObjectsManager::loadHidingItems(const Common::String &file) {
 		_hidingItem[i]._x = READ_LE_INT16((uint16 *)ptr + curBufIdx + 1);
 		_hidingItem[i]._y = READ_LE_INT16((uint16 *)ptr + curBufIdx + 2);
 		_hidingItem[i]._yOffset = READ_LE_INT16((uint16 *)ptr + curBufIdx + 4);
-		if (spriteData == g_PTRNUL) {
+		if (spriteData == NULL) {
 			_hidingItem[i]._useCount = 0;
 		} else {
 			_hidingItem[i]._spriteData = spriteData;
@@ -4002,9 +4002,9 @@ void ObjectsManager::initVBob() {
 		VBob[idx]._xp = 0;
 		VBob[idx]._yp = 0;
 		VBob[idx]._frameIndex = 0;
-		VBob[idx]._surface = g_PTRNUL;
-		VBob[idx]._spriteData = g_PTRNUL;
-		VBob[idx]._oldSpriteData = g_PTRNUL;
+		VBob[idx]._surface = NULL;
+		VBob[idx]._spriteData = NULL;
+		VBob[idx]._oldSpriteData = NULL;
 	}
 }
 
@@ -4015,8 +4015,8 @@ void ObjectsManager::clearVBob() {
 		VBob[idx]._yp = 0;
 		VBob[idx]._frameIndex = 0;
 		VBob[idx]._surface = _vm->_globals->freeMemory(VBob[idx]._surface);
-		VBob[idx]._spriteData = g_PTRNUL;
-		VBob[idx]._oldSpriteData = g_PTRNUL;
+		VBob[idx]._spriteData = NULL;
+		VBob[idx]._oldSpriteData = NULL;
 	}
 }
 
diff --git a/engines/hopkins/script.cpp b/engines/hopkins/script.cpp
index d100403490..c6046c6a2b 100644
--- a/engines/hopkins/script.cpp
+++ b/engines/hopkins/script.cpp
@@ -759,7 +759,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 		case 46: {
 			_vm->_globals->_checkDistanceFl = true;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 564, 420);
 			_vm->_objectsManager->_zoneNum = -1;
 			do {
@@ -768,7 +768,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_objectsManager->removeSprite(0);
 			_vm->_globals->_checkDistanceFl = true;
 			_vm->_soundManager->loadSample(1, "SOUND44.WAV");
@@ -984,7 +984,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 			_vm->_objectsManager->_oldCharacterPosX = _vm->_objectsManager->getSpriteX(0);
 			_vm->_objectsManager->resetOldDirection();
 			_vm->_objectsManager->resetHomeRateCounter();
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 445, 332);
 			_vm->_globals->_checkDistanceFl = true;
 			do {
@@ -993,7 +993,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_objectsManager->removeSprite(0);
 			_vm->_objectsManager->setBobAnimation(7);
 			_vm->_objectsManager->setBobAnimDataIdx(7, 0);
@@ -1100,7 +1100,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 			_vm->_objectsManager->_oldCharacterPosX = _vm->_objectsManager->getSpriteX(0);
 			_vm->_objectsManager->resetOldDirection();
 			_vm->_objectsManager->resetHomeRateCounter();
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 119, 268);
 			_vm->_globals->_checkDistanceFl = true;
 			do {
@@ -1109,7 +1109,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_objectsManager->removeSprite(0);
 			_vm->_objectsManager->setBobAnimation(11);
 			_vm->_objectsManager->setBobAnimation(8);
@@ -1415,7 +1415,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 			_vm->_objectsManager->_oldCharacterPosX = _vm->_objectsManager->getSpriteX(0);
 			_vm->_objectsManager->resetOldDirection();
 			_vm->_objectsManager->resetHomeRateCounter();
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			switch (_vm->_globals->_saveData->_data[svField253]) {
 			case 1:
 				_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 201, 294);
@@ -1435,7 +1435,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_objectsManager->removeSprite(0);
 			_vm->_objectsManager->setSpriteIndex(0, 60);
 			_vm->_soundManager->loadSample(1, "SOUND63.WAV");
@@ -1663,7 +1663,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 			_vm->_objectsManager->resetOldDirection();
 			_vm->_objectsManager->resetHomeRateCounter();
 			_vm->_globals->_checkDistanceFl = true;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 361, 325);
 			_vm->_globals->_checkDistanceFl = true;
 			_vm->_objectsManager->_zoneNum = -1;
@@ -1673,7 +1673,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_globals->_exitId = 59;
 			break;
 			}
@@ -1691,7 +1691,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 			_vm->_objectsManager->resetOldDirection();
 			_vm->_objectsManager->resetHomeRateCounter();
 			_vm->_globals->_checkDistanceFl = true;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 361, 325);
 			_vm->_globals->_checkDistanceFl = true;
 			_vm->_objectsManager->_zoneNum = -1;
@@ -1701,7 +1701,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_globals->_exitId = 59;
 			break;
 			}
@@ -1878,7 +1878,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 				_vm->_soundManager->_specialSoundNum = 0;
 			}
 			_vm->_globals->_checkDistanceFl = true;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 330, 418);
 			_vm->_globals->_checkDistanceFl = true;
 			_vm->_objectsManager->_zoneNum = 0;
@@ -1888,7 +1888,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_objectsManager->setSpriteIndex(0, 64);
 			_vm->_globals->_exitId = _vm->_globals->_saveData->_data[svField401];
 			_vm->_globals->_disableInventFl = false;
@@ -1908,7 +1908,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 				_vm->_eventsManager->refreshScreenAndEvents();
 			} while (_vm->_objectsManager->getBobAnimDataIdx(1) != 9);
 			_vm->_objectsManager->stopBobAnimation(1);
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_globals->_checkDistanceFl = true;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 330, 314);
 			_vm->_objectsManager->_zoneNum = 0;
@@ -1919,7 +1919,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_objectsManager->setSpriteIndex(0, 64);
 			_vm->_objectsManager->setBobAnimation(2);
 			_vm->_soundManager->playSoundFile("SOUND66.WAV");
@@ -1999,7 +1999,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 			_vm->_objectsManager->resetOldDirection();
 			_vm->_objectsManager->resetHomeRateCounter();
 			_vm->_globals->_checkDistanceFl = true;
-			_vm->_linesManager->_route = (RouteItem *)g_PTRNUL;
+			_vm->_linesManager->_route = (RouteItem *)NULL;
 			_vm->_linesManager->_route = _vm->_linesManager->findRoute(_vm->_objectsManager->getSpriteX(0), _vm->_objectsManager->getSpriteY(0), 488, 280);
 			_vm->_globals->_checkDistanceFl = true;
 			do {
@@ -2008,7 +2008,7 @@ int ScriptManager::handleOpcode(byte *dataP) {
 
 				_vm->_objectsManager->GOHOME();
 				_vm->_eventsManager->refreshScreenAndEvents();
-			} while (_vm->_linesManager->_route != (RouteItem *)g_PTRNUL);
+			} while (_vm->_linesManager->_route != (RouteItem *)NULL);
 			_vm->_objectsManager->removeSprite(0);
 			bool playFl = false;
 			_vm->_objectsManager->setBobAnimation(7);
diff --git a/engines/hopkins/talk.cpp b/engines/hopkins/talk.cpp
index 819f6bc467..2b0e00392a 100644
--- a/engines/hopkins/talk.cpp
+++ b/engines/hopkins/talk.cpp
@@ -37,10 +37,10 @@ namespace Hopkins {
 
 TalkManager::TalkManager(HopkinsEngine *vm) {
 	_vm = vm;
-	_characterBuffer = g_PTRNUL;
-	_characterPalette = g_PTRNUL;
-	_characterSprite = g_PTRNUL;
-	_characterAnim = g_PTRNUL;
+	_characterBuffer = NULL;
+	_characterPalette = NULL;
+	_characterSprite = NULL;
+	_characterAnim = NULL;
 	_characterSize = 0;
 	_dialogueMesgId1 = _dialogueMesgId2 = _dialogueMesgId3 = _dialogueMesgId4 = 0;
 	_paletteBufferIdx = 0;
@@ -528,7 +528,7 @@ int TalkManager::countBoxLines(int idx, const Common::String &file) {
 
 	f.seek(indexData[idx]);
 	byte *decryptBuf = _vm->_globals->allocMemory(2058);
-	assert(decryptBuf != g_PTRNUL);
+	assert(decryptBuf != NULL);
 
 	f.read(decryptBuf, 2048);
 	f.close();
@@ -713,7 +713,7 @@ bool TalkManager::searchCharacterAnim(int idx, const byte *bufPerso, int animId,
 					loopCond = true;
 				if (bufIndx > bufferSize) {
 					_vm->_animationManager->_animBqe[idx]._enabledFl = false;
-					_vm->_animationManager->_animBqe[idx]._data = g_PTRNUL;
+					_vm->_animationManager->_animBqe[idx]._data = NULL;
 					return false;
 				}
 				++bufIndx;
@@ -762,11 +762,11 @@ void TalkManager::handleAnswer(int zone, int verb) {
 	byte verbObj = verb;
 	
 	bool outerLoopFl;
-	byte *ptr = g_PTRNUL;
+	byte *ptr = NULL;
 	do {
 		outerLoopFl = false;
 		bool tagFound = false;
-		if (_vm->_globals->_answerBuffer == g_PTRNUL)
+		if (_vm->_globals->_answerBuffer == NULL)
 			return;
 
 		byte *curAnswerBuf = _vm->_globals->_answerBuffer;
@@ -786,7 +786,7 @@ void TalkManager::handleAnswer(int zone, int verb) {
 		// 'COD' tag found
 		curAnswerBuf += 5;
 		ptr = _vm->_globals->allocMemory(620);
-		assert(ptr != g_PTRNUL);
+		assert(ptr != NULL);
 		memset(ptr, 0, 620);
 		uint16 curAnswerIdx = 0;
 		int idx = 0;
@@ -1009,7 +1009,7 @@ void TalkManager::animateObject(const Common::String &filename) {
 	searchCharacterPalette(_paletteBufferIdx, true);
 	startCharacterAnim0(_paletteBufferIdx, false);
 	byte *oldAnswerBufferPtr = _vm->_globals->_answerBuffer;
-	_vm->_globals->_answerBuffer = g_PTRNUL;
+	_vm->_globals->_answerBuffer = NULL;
 	_vm->_globals->_freezeCharacterFl = true;
 	_vm->_objectsManager->loadLinkFile(screenFilename);
 	_vm->_objectsManager->_charactersEnabledFl = true;