Add const's to many interfaces of engines/draci/

svn-id: r44331

14 files changed, 205 insertions, 198 deletions

diff --git a/engines/draci/animation.cpp b/engines/draci/animation.cpp
index 248cc09197..880191d90f 100644
--- a/engines/draci/animation.cpp
+++ b/engines/draci/animation.cpp
@@ -1,3 +1,4 @@
+
 /* ScummVM - Graphic Adventure Engine
  *
  * ScummVM is the legal property of its developers, whose names
@@ -48,7 +49,7 @@ Animation::~Animation() {
 	deleteFrames();
 }
 
-bool Animation::isLooping() {
+bool Animation::isLooping() const {
 	return _looping;
 }
 
@@ -68,7 +69,7 @@ void Animation::setLooping(bool looping) {
 		looping, _id);
 }
 
-void Animation::markDirtyRect(Surface *surface) {
+void Animation::markDirtyRect(Surface *surface) const {
 	// Fetch the current frame's rectangle
 	Drawable *frame = _frames[_currentFrame];
 	Common::Rect frameRect = frame->getRect();			
@@ -77,8 +78,8 @@ void Animation::markDirtyRect(Surface *surface) {
 	frameRect.translate(_relX, _relY);
 	
 	// Take animation scaling into account
-	frameRect.setWidth(frameRect.width() * _scaleX);
-	frameRect.setHeight(frameRect.height() * _scaleY);
+	frameRect.setWidth((int) (frameRect.width() * _scaleX));
+	frameRect.setHeight((int) (frameRect.height() * _scaleY));
 
 	// Mark the rectangle dirty on the surface
 	surface->markDirtyRect(frameRect);
@@ -117,7 +118,7 @@ void Animation::nextFrame(bool force) {
 	_currentFrame, _frames.size(), frame->getX(), frame->getY());
 }
 
-uint Animation::nextFrameNum() {
+uint Animation::nextFrameNum() const {
 
 	if (_paused) 
 		return _currentFrame;
@@ -157,7 +158,9 @@ void Animation::drawFrame(Surface *surface) {
 
 		// Take into account per-animation scaling and adjust the current frames dimensions	
 		if (_scaleX != 1.0 || _scaleY != 1.0)
-			frame->setScaled(scaledWidth * _scaleX, scaledHeight * _scaleY);
+			frame->setScaled(
+				(int) (scaledWidth * _scaleX),
+				(int) (scaledHeight * _scaleY));
 
 		// Draw frame
 		frame->drawScaled(surface, false);
@@ -175,7 +178,7 @@ void Animation::setID(int id) {
 	_id = id;
 }
 
-int Animation::getID() {
+int Animation::getID() const {
 	return _id;
 }
 
@@ -183,19 +186,19 @@ void Animation::setZ(uint z) {
 	_z = z;
 }
 
-uint Animation::getZ() {
+uint Animation::getZ() const {
 	return _z;
 }
 
-int Animation::getRelativeX() {
+int Animation::getRelativeX() const {
 	return _relX;
 }
 
-int Animation::getRelativeY() {
+int Animation::getRelativeY() const {
 	return _relY;
 }
 
-bool Animation::isPlaying() {
+bool Animation::isPlaying() const {
 	return _playing;
 }
 
@@ -204,7 +207,7 @@ void Animation::setPlaying(bool playing) {
 	_playing = playing;
 }
 
-bool Animation::isPaused() {
+bool Animation::isPaused() const {
 	return _paused;
 }
 
@@ -224,11 +227,11 @@ void Animation::setScaleFactors(double scaleX, double scaleY) {
 	_scaleY = scaleY;
 }
 
-double Animation::getScaleX() {
+double Animation::getScaleX() const {
 	return _scaleX;
 }
 
-double Animation::getScaleY() {
+double Animation::getScaleY() const {
 	return _scaleY;
 }
 
@@ -236,7 +239,7 @@ void Animation::addFrame(Drawable *frame) {
 	_frames.push_back(frame);	
 }
 
-int Animation::getIndex() {
+int Animation::getIndex() const {
 	return _index;
 }
 
@@ -259,11 +262,11 @@ Drawable *Animation::getFrame(int frameNum) {
 	}
 }
 
-uint Animation::getFrameCount() {
+uint Animation::getFrameCount() const {
 	return _frames.size();
 }
 
-uint Animation::currentFrameNum() {
+uint Animation::currentFrameNum() const {
 	return _currentFrame;
 }
 
@@ -614,7 +617,9 @@ int AnimationManager::getTopAnimationID(int x, int y) {
 
 		// Take into account per-animation scaling and adjust the current frames dimensions	
 		if (anim->getScaleX() != 1.0 || anim->getScaleY() != 1.0)
-			frame->setScaled(scaledWidth * anim->getScaleX(), scaledHeight * anim->getScaleY());
+			frame->setScaled(
+				(int) (scaledWidth * anim->getScaleX()),
+				(int) (scaledHeight * anim->getScaleY()));
 
 		if (frame->getRect().contains(x, y)) {
 
diff --git a/engines/draci/animation.h b/engines/draci/animation.h
index 5d7c0bf7b6..83161cd639 100644
--- a/engines/draci/animation.h
+++ b/engines/draci/animation.h
@@ -65,11 +65,11 @@ public:
 	Animation(DraciEngine *v, int index);
 	~Animation();	
 	
-	uint getZ();
+	uint getZ() const;
 	void setZ(uint z);
 	
 	void setID(int id);
-	int getID();
+	int getID() const;
 
 	void nextFrame(bool force = false);
 	void drawFrame(Surface *surface);
@@ -77,31 +77,31 @@ public:
 	void addFrame(Drawable *frame);
 	Drawable *getFrame(int frameNum = kCurrentFrame);
 	void setCurrentFrame(uint frame);
-	uint currentFrameNum();
-	uint getFrameCount();
+	uint currentFrameNum() const;
+	uint getFrameCount() const;
 	void deleteFrames();
 
-	bool isPlaying();
+	bool isPlaying() const;
 	void setPlaying(bool playing);
 
-	bool isPaused();
+	bool isPaused() const;
 	void setPaused(bool paused);
 
-	bool isLooping();
+	bool isLooping() const;
 	void setLooping(bool looping);
 
 	void setRelative(int relx, int rely);
-	int getRelativeX();
-	int getRelativeY();
+	int getRelativeX() const;
+	int getRelativeY() const;
 
-	int getIndex();
+	int getIndex() const;
 	void setIndex(int index);
 
 	void setScaleFactors(double scaleX, double scaleY);
-	double getScaleX();
-	double getScaleY();
+	double getScaleX() const;
+	double getScaleY() const;
 
-	void markDirtyRect(Surface *surface);
+	void markDirtyRect(Surface *surface) const;
 
 	// Animation callbacks
 
@@ -113,7 +113,7 @@ public:
 
 private:
 	
-	uint nextFrameNum();
+	uint nextFrameNum() const;
 
 	/** Internal animation ID 
 	  *	(as specified in the data files and the bytecode)
diff --git a/engines/draci/game.cpp b/engines/draci/game.cpp
index 4d4755b419..6ebfb2729c 100644
--- a/engines/draci/game.cpp
+++ b/engines/draci/game.cpp
@@ -660,7 +660,7 @@ void Game::updateTitle() {
 	}
 }	
 
-int Game::getObjectWithAnimation(int animID) {
+int Game::getObjectWithAnimation(int animID) const {
 	for (uint i = 0; i < _info._numObjects; ++i) {
 		GameObject *obj = &_objects[i];
 	
@@ -970,11 +970,11 @@ void Game::runDialogueProg(GPL2Program prog, int offset) {
 	_vm->_anims->deleteAfterIndex(lastAnimIndex);
 }
 
-bool Game::isDialogueBegin() {
+bool Game::isDialogueBegin() const {
 	return _dialogueBegin;
 }
 
-bool Game::shouldExitDialogue() {
+bool Game::shouldExitDialogue() const {
 	return _dialogueExit;
 }
 
@@ -982,11 +982,11 @@ void Game::setDialogueExit(bool exit) {
 	_dialogueExit = exit;
 }
 
-int Game::getDialogueBlockNum() {
+int Game::getDialogueBlockNum() const {
 	return _blockNum;
 }
 
-int Game::getDialogueVar(int dialogueID) {
+int Game::getDialogueVar(int dialogueID) const {
 	return _dialogueVars[dialogueID];
 }
 
@@ -994,23 +994,23 @@ void Game::setDialogueVar(int dialogueID, int value) {
 	_dialogueVars[dialogueID] = value;
 }
 
-int Game::getCurrentDialogue() {
+int Game::getCurrentDialogue() const {
 	return _currentDialogue;
 }
 
-int Game::getDialogueLastBlock() {
+int Game::getDialogueLastBlock() const {
 	return _lastBlock;
 }
 
-int Game::getDialogueLinesNum() {
+int Game::getDialogueLinesNum() const {
 	return _dialogueLinesNum;	
 }
 
-int Game::getDialogueCurrentBlock() {
+int Game::getDialogueCurrentBlock() const {
 	return _currentBlock;	
 }
 
-int Game::getCurrentDialogueOffset() {
+int Game::getCurrentDialogueOffset() const {
 	return _dialogueOffsets[_currentDialogue];
 }
 
@@ -1322,7 +1322,7 @@ GameObject *Game::getObject(uint objNum) {
 	return _objects + objNum;
 }
 
-uint Game::getNumObjects() {
+uint Game::getNumObjects() const {
 	return _info._numObjects;
 }
 
@@ -1427,7 +1427,7 @@ void Game::runGateProgram(int gate) {
 	setExitLoop(false);
 }
 
-int Game::getRoomNum() {
+int Game::getRoomNum() const {
 	return _currentRoom._roomNum;
 }
 
@@ -1435,7 +1435,7 @@ void Game::setRoomNum(int room) {
 	_newRoom = room;
 }
 
-int Game::getGateNum() {
+int Game::getGateNum() const {
 	return _currentGate;
 }
 
@@ -1451,15 +1451,15 @@ void Game::setLoopSubstatus(LoopSubstatus status) {
 	_loopSubstatus = status;
 }
 
-LoopStatus Game::getLoopStatus() {
+LoopStatus Game::getLoopStatus() const {
 	return _loopStatus;
 }
 
-LoopSubstatus Game::getLoopSubstatus() {
+LoopSubstatus Game::getLoopSubstatus() const {
 	return _loopSubstatus;
 }
 
-int Game::getVariable(int numVar) {
+int Game::getVariable(int numVar) const {
 	return _variables[numVar];
 }
 
@@ -1467,7 +1467,7 @@ void Game::setVariable(int numVar, int value) {
 	_variables[numVar] = value;
 }
 
-int Game::getItemStatus(int itemID) {
+int Game::getItemStatus(int itemID) const {
 	return _itemStatus[itemID];
 }
 
@@ -1475,7 +1475,7 @@ void Game::setItemStatus(int itemID, int status) {
 	_itemStatus[itemID] = status;	
 }
 
-int Game::getCurrentItem() {
+int Game::getCurrentItem() const {
 	return _currentItem;
 }
 
@@ -1483,7 +1483,7 @@ void Game::setCurrentItem(int itemID) {
 	_currentItem = itemID;
 }
 
-Person *Game::getPerson(int personID) {
+const Person *Game::getPerson(int personID) const {
 	return &_persons[personID];
 }
 
@@ -1491,7 +1491,7 @@ void Game::setSpeechTick(uint tick) {
 	_speechTick = tick;
 }
 
-int Game::getEscRoom() {
+int Game::getEscRoom() const {
 	return _currentRoom._escRoom;
 }
 
@@ -1499,7 +1499,7 @@ void Game::schedulePalette(int paletteID) {
 	_scheduledPalette = paletteID;
 }
 
-int Game::getScheduledPalette() {
+int Game::getScheduledPalette() const {
 	return _scheduledPalette;
 }
 
@@ -1509,7 +1509,7 @@ int Game::getScheduledPalette() {
  * all animations that have an index greater than the one marked.
  */
 
-int Game::getMarkedAnimationIndex() {
+int Game::getMarkedAnimationIndex() const {
 	return _markedAnimationIndex;
 }
 
@@ -1530,7 +1530,7 @@ Game::~Game() {
 }
 
 
-bool WalkingMap::isWalkable(int x, int y) {
+bool WalkingMap::isWalkable(int x, int y) const {
 
 	// Convert to map pixels
 	x = x / _deltaX;
@@ -1555,7 +1555,7 @@ bool WalkingMap::isWalkable(int x, int y) {
  *	TODO: Study this algorithm in more detail so it can be documented properly and
  * 	possibly improved / simplified.
  */
-Common::Point WalkingMap::findNearestWalkable(int startX, int startY, Common::Rect searchRect) {
+Common::Point WalkingMap::findNearestWalkable(int startX, int startY, Common::Rect searchRect) const {
 
 	// If the starting point is walkable, just return that
 	if (searchRect.contains(startX, startY) && isWalkable(startX, startY)) {
diff --git a/engines/draci/game.h b/engines/draci/game.h
index 0197b167b6..8187438979 100644
--- a/engines/draci/game.h
+++ b/engines/draci/game.h
@@ -120,8 +120,8 @@ public:
 		_data = data + mapReader.pos();
 	}
 
-	bool isWalkable(int x, int y);
-	Common::Point findNearestWalkable(int x, int y, Common::Rect searchRect);
+	bool isWalkable(int x, int y) const;
+	Common::Point findNearestWalkable(int x, int y, Common::Rect searchRect) const;
 
 private:
 	int _realWidth, _realHeight;
@@ -236,7 +236,7 @@ public:
 	void changeRoom(uint roomNum);
 
 	// HACK: this is only for testing
-	int nextRoomNum() { 
+	int nextRoomNum() const { 
 		int n = _currentRoom._roomNum;
 		n = n < 37 ? n+1 : n;
 
@@ -248,7 +248,7 @@ public:
 	}
 
 	// HACK: same as above
-	int prevRoomNum() { 
+	int prevRoomNum() const { 
 		int n = _currentRoom._roomNum;
 		n = n > 0 ? n-1 : n;
 
@@ -268,43 +268,43 @@ public:
 	void loadWalkingMap(int mapID = kDefaultRoomMap);
 	void loadItem(int itemID);
 
-	uint getNumObjects();
+	uint getNumObjects() const;
 	GameObject *getObject(uint objNum);
-	int getObjectWithAnimation(int animID);
+	int getObjectWithAnimation(int animID) const;
 
-	int getVariable(int varNum);
+	int getVariable(int varNum) const;
 	void setVariable(int varNum, int value);	
 
-	Person *getPerson(int personID);
+	const Person *getPerson(int personID) const;
 
-	int getRoomNum();
+	int getRoomNum() const;
 	void setRoomNum(int room);
 
-	int getGateNum();
+	int getGateNum() const;
 	void setGateNum(int gate);
 
-	int getItemStatus(int itemID);
+	int getItemStatus(int itemID) const;
 	void setItemStatus(int itemID, int status);
-	int getCurrentItem();
+	int getCurrentItem() const;
 	void setCurrentItem(int itemID);
 	void removeItem(int itemID);
 	void putItem(int itemID, int position);
 	void addItem(int itemID);
 
-	int getEscRoom();
+	int getEscRoom() const;
 
-	int getMarkedAnimationIndex();
+	int getMarkedAnimationIndex() const;
 	void setMarkedAnimationIndex(int index);
 
 	void setLoopStatus(LoopStatus status);
 	void setLoopSubstatus(LoopSubstatus status);
-	LoopStatus getLoopStatus();
-	LoopSubstatus getLoopSubstatus();
+	LoopStatus getLoopStatus() const;
+	LoopSubstatus getLoopSubstatus() const;
 
-	bool shouldQuit() { return _shouldQuit; }
+	bool shouldQuit() const { return _shouldQuit; }
 	void setQuit(bool quit) { _shouldQuit = quit; }
 
-	bool shouldExitLoop() { return _shouldExitLoop; }
+	bool shouldExitLoop() const { return _shouldExitLoop; }
 	void setExitLoop(bool exit) { _shouldExitLoop = exit; }
 
 	void runGateProgram(int gate);
@@ -324,20 +324,20 @@ public:
 	void dialogueDone();
 	void runDialogueProg(GPL2Program, int offset);
 
-	bool isDialogueBegin();
-	bool shouldExitDialogue();
+	bool isDialogueBegin() const;
+	bool shouldExitDialogue() const;
 	void setDialogueExit(bool exit);
-	int getDialogueBlockNum();
-	int getDialogueVar(int dialogueID);
+	int getDialogueBlockNum() const;
+	int getDialogueVar(int dialogueID) const;
 	void setDialogueVar(int dialogueID, int value);
-	int getCurrentDialogue();
-	int getDialogueCurrentBlock();
-	int getDialogueLastBlock();
-	int getDialogueLinesNum();
-	int getCurrentDialogueOffset();
+	int getCurrentDialogue() const;
+	int getDialogueCurrentBlock() const;
+	int getDialogueLastBlock() const;
+	int getDialogueLinesNum() const;
+	int getCurrentDialogueOffset() const;
 
 	void schedulePalette(int paletteID);
-	int getScheduledPalette();
+	int getScheduledPalette() const;
 
 private:
 	DraciEngine *_vm;
diff --git a/engines/draci/mouse.cpp b/engines/draci/mouse.cpp
index 53c227d626..e1b56a7961 100644
--- a/engines/draci/mouse.cpp
+++ b/engines/draci/mouse.cpp
@@ -80,7 +80,7 @@ void Mouse::cursorOff() {
 	CursorMan.showMouse(false);
 }
 
-bool Mouse::isCursorOn() {
+bool Mouse::isCursorOn() const {
 	return CursorMan.isVisible();
 }
 
diff --git a/engines/draci/mouse.h b/engines/draci/mouse.h
index d6df7f312d..8a6496fda9 100644
--- a/engines/draci/mouse.h
+++ b/engines/draci/mouse.h
@@ -48,18 +48,18 @@ public:
 	void handleEvent(Common::Event event);
 	void cursorOn();
 	void cursorOff();
-	bool isCursorOn();
+	bool isCursorOn() const;
 	void setPosition(uint16 x, uint16 y);
-	CursorType getCursorType() { return _cursorType; }
+	CursorType getCursorType() const { return _cursorType; }
 	void setCursorType(CursorType cur);
 	void loadItemCursor(int itemID, bool highlighted = false);
-	bool lButtonPressed() { return _lButton; }
-	bool rButtonPressed() { return _rButton; }
+	bool lButtonPressed() const { return _lButton; }
+	bool rButtonPressed() const { return _rButton; }
 	void lButtonSet(bool state) { _lButton = state; }
 	void rButtonSet(bool state) { _rButton = state; }
 
-	uint16 getPosX() { return _x; }
-	uint16 getPosY() { return _y; }
+	uint16 getPosX() const { return _x; }
+	uint16 getPosY() const { return _y; }
 
 private:
 	uint16 _x, _y;
diff --git a/engines/draci/screen.cpp b/engines/draci/screen.cpp
index dbdbf15701..5d3c612978 100644
--- a/engines/draci/screen.cpp
+++ b/engines/draci/screen.cpp
@@ -60,7 +60,7 @@ void Screen::setPaletteEmpty(unsigned int numEntries) {
  *		  start Index of the colour where replacement should start
  *		  num Number of colours to replace 
  */
-void Screen::setPalette(byte *data, uint16 start, uint16 num) {
+void Screen::setPalette(const byte *data, uint16 start, uint16 num) {
 
 	Common::MemoryReadStream pal(data, 3 * kNumColours);
 	pal.seek(start * 4);
@@ -85,9 +85,9 @@ void Screen::setPalette(byte *data, uint16 start, uint16 num) {
 /**
  * @brief Copies the current memory screen buffer to the real screen
  */
-void Screen::copyToScreen() const {
-	Common::List<Common::Rect> *dirtyRects = _surface->getDirtyRects();
-	Common::List<Common::Rect>::iterator it;
+void Screen::copyToScreen() {
+	const Common::List<Common::Rect> *dirtyRects = _surface->getDirtyRects();
+	Common::List<Common::Rect>::const_iterator it;
 	
 	// If a full update is needed, update the whole screen	
 	if (_surface->needsFullUpdate()) {
@@ -119,7 +119,7 @@ void Screen::copyToScreen() const {
  *
  * Clears the screen and marks the whole screen dirty.
  */
-void Screen::clearScreen() const {
+void Screen::clearScreen() {
 	byte *ptr = (byte *)_surface->getBasePtr(0, 0);
 
 	_surface->markDirty();
@@ -133,7 +133,7 @@ void Screen::clearScreen() const {
  *
  * Fills the screen with the specified colour and marks the whole screen dirty.
  */
-void Screen::fillScreen(uint8 colour) const {
+void Screen::fillScreen(uint8 colour) {
 	_surface->fill(colour);
 	_surface->markDirty();
 }
diff --git a/engines/draci/screen.h b/engines/draci/screen.h
index 42dcf40bae..b9c3d1b4d2 100644
--- a/engines/draci/screen.h
+++ b/engines/draci/screen.h
@@ -47,11 +47,11 @@ public:
 	~Screen();
 
 	void setPaletteEmpty(unsigned int numEntries = kNumColours);
-	void setPalette(byte *data, uint16 start, uint16 num);
+	void setPalette(const byte *data, uint16 start, uint16 num);
 	byte *getPalette() const;
-	void copyToScreen() const;
-	void clearScreen() const;
-	void fillScreen(uint8 colour) const;
+	void copyToScreen();
+	void clearScreen();
+	void fillScreen(uint8 colour);
 	Surface *getSurface();	
 	void drawRect(Common::Rect &r, uint8 colour);
 
diff --git a/engines/draci/script.cpp b/engines/draci/script.cpp
index 9160b92c18..645bd136b6 100644
--- a/engines/draci/script.cpp
+++ b/engines/draci/script.cpp
@@ -151,65 +151,65 @@ enum mathExpressionObject {
 
 /* GPL operators */
 
-int Script::operAnd(int op1, int op2) {
+int Script::operAnd(int op1, int op2) const {
 	return op1 & op2;
 }
 
-int Script::operOr(int op1, int op2) {
+int Script::operOr(int op1, int op2) const {
 	return op1 | op2;
 }
 
-int Script::operXor(int op1, int op2) {
+int Script::operXor(int op1, int op2) const {
 	return op1 ^ op2;
 }
 
-int Script::operEqual(int op1, int op2) {
+int Script::operEqual(int op1, int op2) const {
 	return op1 == op2;
 }
 
-int Script::operNotEqual(int op1, int op2) {
+int Script::operNotEqual(int op1, int op2) const {
 	return op1 != op2;
 }
 
-int Script::operLess(int op1, int op2) {
+int Script::operLess(int op1, int op2) const {
 	return op1 < op2;
 }
 
-int Script::operGreater(int op1, int op2) {
+int Script::operGreater(int op1, int op2) const {
 	return op1 > op2;
 }
 
-int Script::operGreaterOrEqual(int op1, int op2) {
+int Script::operGreaterOrEqual(int op1, int op2) const {
 	return op1 >= op2;
 }
 
-int Script::operLessOrEqual(int op1, int op2) {
+int Script::operLessOrEqual(int op1, int op2) const {
 	return op1 <= op2;
 }
 
-int Script::operMul(int op1, int op2) {
+int Script::operMul(int op1, int op2) const {
 	return op1 * op2;
 }
 
-int Script::operAdd(int op1, int op2) {
+int Script::operAdd(int op1, int op2) const {
 	return op1 + op2;
 }
 
-int Script::operSub(int op1, int op2) {
+int Script::operSub(int op1, int op2) const {
 	return op1 - op2;
 }
 
-int Script::operDiv(int op1, int op2) {
+int Script::operDiv(int op1, int op2) const {
 	return op1 / op2;
 }
 
-int Script::operMod(int op1, int op2) {
+int Script::operMod(int op1, int op2) const {
 	return op1 % op2;
 }
 
 /* GPL functions */
 
-int Script::funcRandom(int n) {
+int Script::funcRandom(int n) const {
 
 // The function needs to return numbers in the [0..n-1] range so we need to deduce 1
 // (RandomSource::getRandomNumber returns a number in the range [0..n])
@@ -218,58 +218,58 @@ int Script::funcRandom(int n) {
 	return _vm->_rnd.getRandomNumber(n);
 }
 
-int Script::funcAtBegin(int yesno) {
+int Script::funcAtBegin(int yesno) const {
 	return _vm->_game->isDialogueBegin() == (bool)yesno;
 }	
 
-int Script::funcLastBlock(int blockID) {
+int Script::funcLastBlock(int blockID) const {
 	blockID -= 1;
 
 	return _vm->_game->getDialogueLastBlock() == blockID;
 }
 
-int Script::funcBlockVar(int blockID) {
+int Script::funcBlockVar(int blockID) const {
 	blockID -= 1;
 	
 	const int currentOffset = _vm->_game->getCurrentDialogueOffset();
 	return _vm->_game->getDialogueVar(currentOffset + blockID);
 }
 
-int Script::funcHasBeen(int blockID) {
+int Script::funcHasBeen(int blockID) const {
 	blockID -= 1;
 
 	const int currentOffset = _vm->_game->getCurrentDialogueOffset();
 	return _vm->_game->getDialogueVar(currentOffset + blockID) > 0;
 }
 
-int Script::funcMaxLine(int lines) {
+int Script::funcMaxLine(int lines) const {
 	return _vm->_game->getDialogueLinesNum() < lines;
 }
 
-int Script::funcNot(int n) {
+int Script::funcNot(int n) const {
 	return !n;
 }
 
-int Script::funcIsIcoOn(int itemID) {
+int Script::funcIsIcoOn(int itemID) const {
 	itemID -= 1;
 
 	return _vm->_game->getItemStatus(itemID) == 1;
 } 
 
-int Script::funcIcoStat(int itemID) {
+int Script::funcIcoStat(int itemID) const {
 	itemID -= 1;
 
 	int status = _vm->_game->getItemStatus(itemID);
 	return (status == 1) ? 1 : 2;
 }
 
-int Script::funcIsIcoAct(int itemID) {
+int Script::funcIsIcoAct(int itemID) const {
 	itemID -= 1;
 
 	return _vm->_game->getCurrentItem() == itemID;
 }
 
-int Script::funcActIco(int itemID) {
+int Script::funcActIco(int itemID) const {
 	
 	// The parameter seems to be an omission in the original player since it's not
 	// used in the implementation of the function. It's possible that the functions were
@@ -279,7 +279,7 @@ int Script::funcActIco(int itemID) {
 	return _vm->_game->getCurrentItem();
 }
 
-int Script::funcIsObjOn(int objID) {
+int Script::funcIsObjOn(int objID) const {
 	objID -= 1;
 
 	GameObject *obj = _vm->_game->getObject(objID);
@@ -287,7 +287,7 @@ int Script::funcIsObjOn(int objID) {
 	return obj->_visible;
 }
 
-int Script::funcIsObjOff(int objID) {
+int Script::funcIsObjOff(int objID) const {
 	objID -= 1;
 
 	GameObject *obj = _vm->_game->getObject(objID);
@@ -297,7 +297,7 @@ int Script::funcIsObjOff(int objID) {
 	return !obj->_visible && obj->_location != -1;
 }
 
-int Script::funcObjStat(int objID) {
+int Script::funcObjStat(int objID) const {
 	objID -= 1;
 
 	GameObject *obj = _vm->_game->getObject(objID);
@@ -313,7 +313,7 @@ int Script::funcObjStat(int objID) {
 	}
 }
 
-int Script::funcIsObjAway(int objID) {
+int Script::funcIsObjAway(int objID) const {
 	objID -= 1;
 
 	GameObject *obj = _vm->_game->getObject(objID);
@@ -322,7 +322,7 @@ int Script::funcIsObjAway(int objID) {
 	return !obj->_visible && obj->_location == -1;
 }
 
-int Script::funcActPhase(int objID) {
+int Script::funcActPhase(int objID) const {
 
 	objID -= 1;	
 
@@ -673,7 +673,7 @@ void Script::talk(Common::Queue<int> &params) {
 	Text *speechFrame = reinterpret_cast<Text *>(speechAnim->getFrame());
 
 	// Fetch person info
-	Person *person = _vm->_game->getPerson(personID);
+	const Person *person = _vm->_game->getPerson(personID);
 
 	// Set the string and text colour
 	surface->markDirtyRect(speechFrame->getRect(true));
@@ -799,7 +799,7 @@ void Script::endCurrentProgram() {
  * @param reader Stream reader set to the beginning of the expression
  */
 
-int Script::handleMathExpression(Common::MemoryReadStream &reader) {
+int Script::handleMathExpression(Common::MemoryReadStream &reader) const {
 	Common::Stack<int> stk;
 	mathExpressionObject obj;
 	GPL2Operator oper;
@@ -907,7 +907,7 @@ int Script::handleMathExpression(Common::MemoryReadStream &reader) {
  *
  * Reference: the function equivalent to this one is called "Can()" in the original engine.
  */
-bool Script::testExpression(GPL2Program program, uint16 offset) {
+bool Script::testExpression(GPL2Program program, uint16 offset) const {
 	
 	// Initialize program reader
 	Common::MemoryReadStream reader(program._bytecode, program._length);
@@ -935,7 +935,7 @@ bool Script::testExpression(GPL2Program program, uint16 offset) {
  * @return NULL if command is not found. Otherwise, a pointer to a GPL2Command
  *         struct representing the command.
  */
-const GPL2Command *Script::findCommand(byte num, byte subnum) {
+const GPL2Command *Script::findCommand(byte num, byte subnum) const {
 	unsigned int i = 0;
 	while (1) {
 
diff --git a/engines/draci/script.h b/engines/draci/script.h
index 86abb5ee9b..2cbdff0f0e 100644
--- a/engines/draci/script.h
+++ b/engines/draci/script.h
@@ -43,8 +43,8 @@ enum {
 };
 
 typedef void (Script::* GPLHandler)(Common::Queue<int> &);
-typedef int  (Script::* GPLOperatorHandler)(int, int);
-typedef int  (Script::* GPLFunctionHandler)(int);
+typedef int  (Script::* GPLOperatorHandler)(int, int) const;
+typedef int  (Script::* GPLFunctionHandler)(int) const;
 
 /**
  *  Represents a single command in the GPL scripting language bytecode.
@@ -89,7 +89,7 @@ public:
 	Script(DraciEngine *vm) : _vm(vm), _jump(0) { setupCommandList(); };	
 
 	int run(GPL2Program program, uint16 offset);
-	bool testExpression(GPL2Program, uint16 offset);
+	bool testExpression(GPL2Program, uint16 offset) const;
 	void endCurrentProgram();
 
 private:
@@ -132,41 +132,41 @@ private:
 	void blackPalette(Common::Queue<int> &params);
 	void loadPalette(Common::Queue<int> &params);
 
-	int operAnd(int op1, int op2);
-	int operOr(int op1, int op2);
-	int operXor(int op1, int op2);
-	int operSub(int op1, int op2);
-	int operAdd(int op1, int op2);
-	int operDiv(int op1, int op2);
-	int operMul(int op1, int op2);
-	int operEqual(int op1, int op2);
-	int operNotEqual(int op1, int op2);
-	int operGreater(int op1, int op2);
-	int operLess(int op1, int op2);
-	int operGreaterOrEqual(int op1, int op2);
-	int operLessOrEqual(int op1, int op2);
-	int operMod(int op1, int op2);
-
-	int funcRandom(int n);
-	int funcNot(int n);
-	int funcIsIcoOn(int iconID);
-	int funcIcoStat(int iconID);
-	int funcActIco(int iconID);
-	int funcIsIcoAct(int iconID);
-	int funcIsObjOn(int objID);
-	int funcIsObjOff(int objID);
-	int funcIsObjAway(int objID);
-	int funcActPhase(int objID);
-	int funcObjStat(int objID);
-	int funcLastBlock(int blockID);
-	int funcAtBegin(int yesno);
-	int funcBlockVar(int blockID);
-	int funcHasBeen(int blockID);
-	int funcMaxLine(int lines);
+	int operAnd(int op1, int op2) const;
+	int operOr(int op1, int op2) const;
+	int operXor(int op1, int op2) const;
+	int operSub(int op1, int op2) const;
+	int operAdd(int op1, int op2) const;
+	int operDiv(int op1, int op2) const;
+	int operMul(int op1, int op2) const;
+	int operEqual(int op1, int op2) const;
+	int operNotEqual(int op1, int op2) const;
+	int operGreater(int op1, int op2) const;
+	int operLess(int op1, int op2) const;
+	int operGreaterOrEqual(int op1, int op2) const;
+	int operLessOrEqual(int op1, int op2) const;
+	int operMod(int op1, int op2) const;
+
+	int funcRandom(int n) const;
+	int funcNot(int n) const;
+	int funcIsIcoOn(int iconID) const;
+	int funcIcoStat(int iconID) const;
+	int funcActIco(int iconID) const;
+	int funcIsIcoAct(int iconID) const;
+	int funcIsObjOn(int objID) const;
+	int funcIsObjOff(int objID) const;
+	int funcIsObjAway(int objID) const;
+	int funcActPhase(int objID) const;
+	int funcObjStat(int objID) const;
+	int funcLastBlock(int blockID) const;
+	int funcAtBegin(int yesno) const;
+	int funcBlockVar(int blockID) const;
+	int funcHasBeen(int blockID) const;
+	int funcMaxLine(int lines) const;
 
 	void setupCommandList();
-	const GPL2Command *findCommand(byte num, byte subnum);
-	int handleMathExpression(Common::MemoryReadStream &reader);
+	const GPL2Command *findCommand(byte num, byte subnum) const;
+	int handleMathExpression(Common::MemoryReadStream &reader) const;
 
 	DraciEngine *_vm;
 };
diff --git a/engines/draci/sprite.cpp b/engines/draci/sprite.cpp
index 8d21453ef6..69465307a4 100644
--- a/engines/draci/sprite.cpp
+++ b/engines/draci/sprite.cpp
@@ -56,7 +56,7 @@ static void transformToRows(byte *img, uint16 width, uint16 height) {
 /**
  *  Constructor for loading sprites from a raw data buffer, one byte per pixel.
  */
-Sprite::Sprite(byte *raw_data, uint16 width, uint16 height, int x, int y, 
+Sprite::Sprite(const byte *raw_data, uint16 width, uint16 height, int x, int y, 
 	bool columnwise) : _data(NULL) {
 
 	 _width = width;
@@ -72,21 +72,22 @@ Sprite::Sprite(byte *raw_data, uint16 width, uint16 height, int x, int y,
 
 	_mirror = false;
 
-	_data = new byte[width * height];
+	byte *data = new byte[width * height];
 	
-	memcpy(_data, raw_data, width * height);
+	memcpy(data, raw_data, width * height);
 
 	// If the sprite is stored column-wise, transform it to row-wise
 	if (columnwise) {
-		transformToRows(_data, width, height);
+		transformToRows(data, width, height);
 	}	
+	_data = data;
 }
 
 /**
  *  Constructor for loading sprites from a sprite-formatted buffer, one byte per 
  *	pixel.
  */
-Sprite::Sprite(byte *sprite_data, uint16 length, int x, int y, bool columnwise) 
+Sprite::Sprite(const byte *sprite_data, uint16 length, int x, int y, bool columnwise) 
 	: _data(NULL) {
 
 	 _x = x;
@@ -104,14 +105,15 @@ Sprite::Sprite(byte *sprite_data, uint16 length, int x, int y, bool columnwise)
 	_scaledWidth = _width;
 	_scaledHeight = _height;
 
-	_data = new byte[_width * _height];
+	byte *data = new byte[_width * _height];
 
-	reader.read(_data, _width * _height);
+	reader.read(data, _width * _height);
 
 	// If the sprite is stored column-wise, transform it to row-wise
 	if (columnwise) {
-		transformToRows(_data, _width, _height);
+		transformToRows(data, _width, _height);
 	}		
+	_data = data;
 }
 
 Sprite::~Sprite() { 
@@ -171,7 +173,7 @@ void Sprite::drawScaled(Surface *surface, bool markDirty) const {
 
 	// Get pointers to source and destination buffers
 	byte *dst = (byte *)surface->getBasePtr(clippedDestRect.left, clippedDestRect.top);
-	byte *src = _data;
+	const byte *src = _data;
 
 	const int transparent = surface->getTransparentColour();
 
@@ -262,7 +264,7 @@ void Sprite::draw(Surface *surface, bool markDirty) const {
 
 	// Get pointers to source and destination buffers
 	byte *dst = (byte *)surface->getBasePtr(clippedDestRect.left, clippedDestRect.top);
-	byte *src = _data;
+	const byte *src = _data;
 
 	const int transparent = surface->getTransparentColour();
 
@@ -350,7 +352,7 @@ void Text::setSpacing(uint spacing) {
 	_spacing = spacing;
 }
 
-uint Text::getLength() {
+uint Text::getLength() const {
 	return _length;
 }
 
diff --git a/engines/draci/sprite.h b/engines/draci/sprite.h
index 2fb668ba65..e59149de42 100644
--- a/engines/draci/sprite.h
+++ b/engines/draci/sprite.h
@@ -94,9 +94,9 @@ protected:
 class Sprite : public Drawable {
 
 public:
-	Sprite(byte *raw_data, uint16 width, uint16 height, int x, int y, bool columnwise);
+	Sprite(const byte *raw_data, uint16 width, uint16 height, int x, int y, bool columnwise);
 	
-	Sprite(byte *sprite_data, uint16 length, int x, int y, bool columnwise); 
+	Sprite(const byte *sprite_data, uint16 length, int x, int y, bool columnwise); 
 
 	~Sprite();
 
@@ -114,7 +114,7 @@ public:
 	DrawableType getType() const { return kDrawableSprite; }
 
 private:
-	byte *_data;	//!< Pointer to a buffer containing raw sprite data (row-wise)
+	const byte *_data;	//!< Pointer to a buffer containing raw sprite data (row-wise)
 	bool _mirror;
 };
 
@@ -130,7 +130,7 @@ public:
 	void setSpacing(uint spacing);
 	void setFont(Font *font);
 
-	uint getLength();
+	uint getLength() const;
 
 	void draw(Surface *surface, bool markDirty = true) const;
 
diff --git a/engines/draci/surface.cpp b/engines/draci/surface.cpp
index a1e9b0f9ab..12fabd2ec3 100644
--- a/engines/draci/surface.cpp
+++ b/engines/draci/surface.cpp
@@ -91,7 +91,7 @@ void Surface::markClean() {
 /**
  * @brief Checks whether the surface needs a full update
  */
-bool Surface::needsFullUpdate() {
+bool Surface::needsFullUpdate() const {
 	return _fullUpdate;
 }
 
@@ -99,14 +99,14 @@ bool Surface::needsFullUpdate() {
  * @brief Fetches the surface's dirty rectangles
  * @return A pointer a list of dirty rectangles
  */
-Common::List<Common::Rect> *Surface::getDirtyRects() {
+const Common::List<Common::Rect> *Surface::getDirtyRects() const {
 	return &_dirtyRects;
 }
 
 /**
  * @brief Returns the current transparent colour of the surface
  */
-uint Surface::getTransparentColour() {
+uint Surface::getTransparentColour() const {
 	return _transparentColour;
 }
 
@@ -134,7 +134,7 @@ void Surface::fill(uint colour) {
  *
  * @return The centered x coordinate
  */
-uint Surface::centerOnX(uint x, uint width) {
+uint Surface::centerOnX(uint x, uint width) const {
 
 	int newX = x - width / 2;
 
@@ -155,7 +155,7 @@ uint Surface::centerOnX(uint x, uint width) {
  *
  * @return The centered y coordinate
  */
-uint Surface::centerOnY(uint y, uint height) {
+uint Surface::centerOnY(uint y, uint height) const {
 	
 	int newY = y - height / 2;
 	
@@ -172,7 +172,7 @@ uint Surface::centerOnY(uint y, uint height) {
  * @brief Returns a Common::Rect corresponding to the surface.
  */
 
-Common::Rect Surface::getRect() {
+Common::Rect Surface::getRect() const {
 	return Common::Rect(w, h);
 }
 
diff --git a/engines/draci/surface.h b/engines/draci/surface.h
index ea3830a97f..5ce92bbd76 100644
--- a/engines/draci/surface.h
+++ b/engines/draci/surface.h
@@ -37,17 +37,17 @@ public:
 	~Surface();
 
 	void markDirtyRect(Common::Rect r);
-	Common::List<Common::Rect> *getDirtyRects();
+	const Common::List<Common::Rect> *getDirtyRects() const;
 	void clearDirtyRects();
 	void markDirty();
 	void markClean();
-	bool needsFullUpdate();
-	uint getTransparentColour();
+	bool needsFullUpdate() const;
+	uint getTransparentColour() const;
 	void setTransparentColour(uint colour);
 	void fill(uint colour);
-	uint centerOnY(uint y, uint height);
-	uint centerOnX(uint x, uint width);
-	Common::Rect getRect();
+	uint centerOnY(uint y, uint height) const;
+	uint centerOnX(uint x, uint width) const;
+	Common::Rect getRect() const;
 
 private:
 	/** The current transparent colour of the surface. See getTransparentColour() and