TITANIC: Adding lots of const prefixes

23 files changed, 127 insertions, 127 deletions

diff --git a/engines/titanic/pet_control/pet_glyphs.h b/engines/titanic/pet_control/pet_glyphs.h
index 7271d6cd61..c07cc5ed9a 100644
--- a/engines/titanic/pet_control/pet_glyphs.h
+++ b/engines/titanic/pet_control/pet_glyphs.h
@@ -101,7 +101,7 @@ public:
 	/**
 	 * Get the bounds for the glyph
 	 */
-	virtual Rect getBounds() { return Rect(); }
+	virtual Rect getBounds() const { return Rect(); }
 
 	/**
 	 * Called for mouse button down messages
diff --git a/engines/titanic/pet_control/pet_real_life.h b/engines/titanic/pet_control/pet_real_life.h
index a4ae67fa6b..40bc87d9b5 100644
--- a/engines/titanic/pet_control/pet_real_life.h
+++ b/engines/titanic/pet_control/pet_real_life.h
@@ -67,7 +67,7 @@ public:
 	/**
 	 * Get the bounds for the section
 	 */
-	virtual Rect getBounds() { return Rect(); }
+	virtual Rect getBounds() const { return Rect(); }
 	
 	/**
 	 * Following are handlers for the various messages that the PET can
diff --git a/engines/titanic/pet_control/pet_section.h b/engines/titanic/pet_control/pet_section.h
index 4047ab03de..8bc427e842 100644
--- a/engines/titanic/pet_control/pet_section.h
+++ b/engines/titanic/pet_control/pet_section.h
@@ -89,7 +89,7 @@ public:
 	/**
 	 * Get the bounds for the section
 	 */
-	virtual Rect getBounds() { return Rect(); }
+	virtual Rect getBounds() const { return Rect(); }
 	
 	/**
 	 * Called when a general change occurs
diff --git a/engines/titanic/true_talk/barbot_script.cpp b/engines/titanic/true_talk/barbot_script.cpp
index 6d69244cd5..ccc583347c 100644
--- a/engines/titanic/true_talk/barbot_script.cpp
+++ b/engines/titanic/true_talk/barbot_script.cpp
@@ -70,7 +70,7 @@ void BarbotScript::setupSentences() {
 	_words.load("Words/Barbot");
 }
 
-int BarbotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) {
+int BarbotScript::chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) {
 	if (tag == MKTAG('D', 'N', 'A', '1') || tag == MKTAG('H', 'H', 'G', 'Q') ||
 			tag == MKTAG('A', 'N', 'S', 'W') || tag == MKTAG('S', 'U', 'M', 'S')) {
 		if (_state < 7) {
@@ -132,7 +132,7 @@ int BarbotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence,
 	return TTnpcScript::chooseResponse(roomScript, sentence, tag);
 }
 
-int BarbotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int BarbotScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	int dialogueId = 0;
 
 	if (roomScript->_scriptId != 112)
@@ -756,7 +756,7 @@ done:
 	return 2;
 }
 
-ScriptChangedResult BarbotScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult BarbotScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	switch (id) {
 	case 1:
 	case 100:
@@ -840,7 +840,7 @@ ScriptChangedResult BarbotScript::scriptChanged(TTroomScript *roomScript, uint i
 	return SCR_2;
 }
 
-int BarbotScript::handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+int BarbotScript::handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder) {
 	switch (tagId) {
 	case MKTAG('A', 'D', 'V', 'T'):
@@ -1015,7 +1015,7 @@ uint BarbotScript::getDialsBitset() const {
 	return bits;
 }
 
-int BarbotScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int BarbotScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	int v34 = getState();
 	uint id = 0;
 
diff --git a/engines/titanic/true_talk/barbot_script.h b/engines/titanic/true_talk/barbot_script.h
index b7a19334d1..1820d77216 100644
--- a/engines/titanic/true_talk/barbot_script.h
+++ b/engines/titanic/true_talk/barbot_script.h
@@ -60,19 +60,19 @@ public:
 	/**
 	 * Chooses and adds a conversation response based on a specified tag Id.
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag);
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag);
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
-	virtual int handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+	virtual int handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder);
 	
 	/**
@@ -93,7 +93,7 @@ public:
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Sets a given dial to be pointing in a specified region (0 to 2)
diff --git a/engines/titanic/true_talk/bellbot_script.cpp b/engines/titanic/true_talk/bellbot_script.cpp
index ddfd315f02..7da2ab6201 100644
--- a/engines/titanic/true_talk/bellbot_script.cpp
+++ b/engines/titanic/true_talk/bellbot_script.cpp
@@ -77,7 +77,7 @@ void BellbotScript::setupSentences() {
 	_entryCount = 0;
 }
 
-int BellbotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int BellbotScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	int val24 = getValue(24);
 	CTrueTalkManager::setFlags(24, 0);
 
@@ -344,7 +344,7 @@ int BellbotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
 	return 2;
 }
 
-ScriptChangedResult BellbotScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult BellbotScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	if (!roomScript)
 		return SCR_2;
 
@@ -415,7 +415,7 @@ ScriptChangedResult BellbotScript::scriptChanged(TTroomScript *roomScript, uint
 	return SCR_2;
 }
 
-int BellbotScript::handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+int BellbotScript::handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder) {
 	switch (tagId) {
 	case MKTAG('A', 'D', 'V', 'T'):
@@ -656,7 +656,7 @@ int BellbotScript::preResponse(uint id) {
 	return newId;
 }
 
-int BellbotScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int BellbotScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	switch (val1) {
 	case 1:
 		addResponse(getDialogueId(*srcIdP));
@@ -789,7 +789,7 @@ void BellbotScript::setValue23(uint id) {
 	CTrueTalkManager::setFlags(23, val);
 }
 
-int BellbotScript::preprocess(TTroomScript *roomScript, TTsentence *sentence) {
+int BellbotScript::preprocess(const TTroomScript *roomScript, const TTsentence *sentence) {
 	if (!roomScript || !sentence)
 		return true;
 
@@ -1588,7 +1588,7 @@ stateFlag = false;
 	return applyFlag ? 2 : 1;
 }
 
-bool BellbotScript::better(TTsentence *sentence, uint id1, uint id2) {
+bool BellbotScript::better(const TTsentence *sentence, uint id1, uint id2) {
 	if (sentence->contains("good") || sentence->localWord("better")) {
 		addResponse(getDialogueId(id1));
 	} else if (sentence->localWord("bad")) {
@@ -1600,7 +1600,7 @@ bool BellbotScript::better(TTsentence *sentence, uint id1, uint id2) {
 	return true;
 }
 
-bool BellbotScript::randomResponse0(TTroomScript *roomScript, uint id) {
+bool BellbotScript::randomResponse0(const TTroomScript *roomScript, uint id) {
 	bool dr0 = getDialRegion(0) == 1;
 	uint newId = getValue(1);
 
@@ -1621,7 +1621,7 @@ bool BellbotScript::randomResponse0(TTroomScript *roomScript, uint id) {
 	return true;
 }
 
-bool BellbotScript::randomResponse1(TTroomScript *roomScript, uint id) {
+bool BellbotScript::randomResponse1(const TTroomScript *roomScript, uint id) {
 	if (getRandomNumber(100) < 10) {
 		addResponse(getDialogueId(201978));
 		applyResponse();
@@ -1636,7 +1636,7 @@ bool BellbotScript::randomResponse1(TTroomScript *roomScript, uint id) {
 	return false;
 }
 
-bool BellbotScript::randomResponse2(TTroomScript *roomScript, uint id) {
+bool BellbotScript::randomResponse2(const TTroomScript *roomScript, uint id) {
 	if (getRandomNumber(100) < 5) {
 		addResponse(getDialogueId(202262));
 		applyResponse();
@@ -1651,7 +1651,7 @@ bool BellbotScript::randomResponse2(TTroomScript *roomScript, uint id) {
 	return false;
 }
 
-void BellbotScript::randomResponse3(TTroomScript *roomScript, uint id) {
+void BellbotScript::randomResponse3(const TTroomScript *roomScript, uint id) {
 	bool result = false;
 	if (roomScript && getRandomNumber(100) < 50)
 		result = addRoomDescription(roomScript);
@@ -1676,7 +1676,7 @@ void BellbotScript::randomResponse3(TTroomScript *roomScript, uint id) {
 	addResponse(getDialogueId(id == 1 ? 202265 : 202263));
 }
 
-void BellbotScript::randomResponse4(TTroomScript *roomScript, uint id) {
+void BellbotScript::randomResponse4(const TTroomScript *roomScript, uint id) {
 	if (getRandomNumber(100) < 4 && id <= 2) {
 		addResponse(getDialogueId(202268));
 	} else {
@@ -1684,7 +1684,7 @@ void BellbotScript::randomResponse4(TTroomScript *roomScript, uint id) {
 	}
 }
 
-int BellbotScript::checkCommonSentences(TTroomScript *roomScript, TTsentence *sentence) {
+int BellbotScript::checkCommonSentences(const TTroomScript *roomScript, const TTsentence *sentence) {
 	if (!roomScript || !sentence)
 		return 1;
 
@@ -1707,7 +1707,7 @@ int BellbotScript::checkCommonSentences(TTroomScript *roomScript, TTsentence *se
 	return 0;
 }
 
-bool BellbotScript::checkCommonWords(TTroomScript *roomScript, TTsentence *sentence) {
+bool BellbotScript::checkCommonWords(const TTroomScript *roomScript, const TTsentence *sentence) {
 	if (!roomScript || !sentence)
 		return 0;
 	CTrueTalkManager::setFlags(23, 0);
@@ -1812,7 +1812,7 @@ bool BellbotScript::checkCommonWords(TTroomScript *roomScript, TTsentence *sente
 	return true;
 }
 
-uint BellbotScript::getRoomDialogueId(TTroomScript *roomScript) {
+uint BellbotScript::getRoomDialogueId(const TTroomScript *roomScript) {
 	if (!roomScript)
 		return 0;
 
@@ -1824,7 +1824,7 @@ uint BellbotScript::getRoomDialogueId(TTroomScript *roomScript) {
 	return 0;
 }
 
-bool BellbotScript::addRoomDescription(TTroomScript *roomScript) {
+bool BellbotScript::addRoomDescription(const TTroomScript *roomScript) {
 	if (!roomScript)
 		return false;
 
diff --git a/engines/titanic/true_talk/bellbot_script.h b/engines/titanic/true_talk/bellbot_script.h
index ee5a679041..3080b56902 100644
--- a/engines/titanic/true_talk/bellbot_script.h
+++ b/engines/titanic/true_talk/bellbot_script.h
@@ -64,28 +64,28 @@ private:
 	/**
 	 * Does preprocessing for the sentence
 	 */
-	int preprocess(TTroomScript *roomScript, TTsentence *sentence);
+	int preprocess(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Checks for good, better, or bad in the sentence
 	 */
-	bool better(TTsentence *sentence, uint id1, uint id2);
+	bool better(const TTsentence *sentence, uint id1, uint id2);
 
-	bool randomResponse0(TTroomScript *roomScript, uint id);
-	bool randomResponse1(TTroomScript *roomScript, uint id);
-	bool randomResponse2(TTroomScript *roomScript, uint id);
-	void randomResponse3(TTroomScript *roomScript, uint id);
-	void randomResponse4(TTroomScript *roomScript, uint id);
+	bool randomResponse0(const TTroomScript *roomScript, uint id);
+	bool randomResponse1(const TTroomScript *roomScript, uint id);
+	bool randomResponse2(const TTroomScript *roomScript, uint id);
+	void randomResponse3(const TTroomScript *roomScript, uint id);
+	void randomResponse4(const TTroomScript *roomScript, uint id);
 
-	int checkCommonSentences(TTroomScript *roomScript, TTsentence *sentence);
-	bool checkCommonWords(TTroomScript *roomScript, TTsentence *sentence);
+	int checkCommonSentences(const TTroomScript *roomScript, const TTsentence *sentence);
+	bool checkCommonWords(const TTroomScript *roomScript, const TTsentence *sentence);
 
-	uint getRoomDialogueId(TTroomScript *roomScript);
+	uint getRoomDialogueId(const TTroomScript *roomScript);
 	
 	/**
 	 * Adds a description of the room to the conversation response
 	 */
-	bool addRoomDescription(TTroomScript *roomScript);
+	bool addRoomDescription(const TTroomScript *roomScript);
 public:
 	BellbotScript(int val1, const char *charClass, int v2,
 		const char *charName, int v3, int val2);
@@ -93,14 +93,14 @@ public:
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
-	virtual int handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+	virtual int handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder);
 
 	/**
@@ -116,7 +116,7 @@ public:
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Handles a randomzied response
diff --git a/engines/titanic/true_talk/deskbot_script.cpp b/engines/titanic/true_talk/deskbot_script.cpp
index c955e7e925..d9bab2e237 100644
--- a/engines/titanic/true_talk/deskbot_script.cpp
+++ b/engines/titanic/true_talk/deskbot_script.cpp
@@ -60,7 +60,7 @@ void DeskbotScript::setupSentences() {
 	_entryCount = 0;
 }
 
-int DeskbotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int DeskbotScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	if (roomScript->_scriptId != 110)
 		return 2;
 
@@ -76,12 +76,12 @@ int DeskbotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
 	return 0;
 }
 
-ScriptChangedResult DeskbotScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult DeskbotScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	warning("TODO");
 	return SCR_1;
 }
 
-int DeskbotScript::handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+int DeskbotScript::handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder) {
 	switch (tagId) {
 	case MKTAG('A', 'D', 'V', 'T'):
@@ -281,7 +281,7 @@ uint DeskbotScript::getDialsBitset() const {
 		return getDialRegion(0) ? 0 : 1;
 }
 
-int DeskbotScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int DeskbotScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	uint id;
 
 	switch (val1) {
diff --git a/engines/titanic/true_talk/deskbot_script.h b/engines/titanic/true_talk/deskbot_script.h
index 55896a2425..8f37b4b227 100644
--- a/engines/titanic/true_talk/deskbot_script.h
+++ b/engines/titanic/true_talk/deskbot_script.h
@@ -94,14 +94,14 @@ public:
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
-	virtual int handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+	virtual int handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder);
 
 	/**
@@ -122,7 +122,7 @@ public:
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Handles a randomzied response
diff --git a/engines/titanic/true_talk/doorbot_script.cpp b/engines/titanic/true_talk/doorbot_script.cpp
index 7319058c0a..6a31f93111 100644
--- a/engines/titanic/true_talk/doorbot_script.cpp
+++ b/engines/titanic/true_talk/doorbot_script.cpp
@@ -71,7 +71,7 @@ void DoorbotScript::setupSentences() {
 	_entryCount = 0;
 }
 
-int DoorbotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) {
+int DoorbotScript::chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) {
 	if (tag == MKTAG('D', 'N', 'A', '1') || tag == MKTAG('H', 'H', 'G', 'Q') ||
 		tag == MKTAG('A', 'N', 'S', 'W') || tag == MKTAG('S', 'U', 'M', 'S')) {
 		if (_stateIndex > 9)
@@ -127,17 +127,17 @@ int DoorbotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence
 	return TTnpcScript::chooseResponse(roomScript, sentence, tag);
 }
 
-int DoorbotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int DoorbotScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	// TODO
 	return 0;
 }
 
-ScriptChangedResult DoorbotScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult DoorbotScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	warning("TODO");
 	return SCR_1;
 }
 
-int DoorbotScript::handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+int DoorbotScript::handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder) {
 	switch (tagId) {
 	case MKTAG('A', 'D', 'V', 'T'):
@@ -336,7 +336,7 @@ uint DoorbotScript::getDialsBitset() const {
 	return bits;
 }
 
-int DoorbotScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int DoorbotScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	int id2, id = 0;
 
 	switch (val1) {
diff --git a/engines/titanic/true_talk/doorbot_script.h b/engines/titanic/true_talk/doorbot_script.h
index be653fd1b6..ec615295b5 100644
--- a/engines/titanic/true_talk/doorbot_script.h
+++ b/engines/titanic/true_talk/doorbot_script.h
@@ -58,19 +58,19 @@ public:
 	/**
 	 * Chooses and adds a conversation response based on a specified tag Id.
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag);
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag);
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
-	virtual int handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+	virtual int handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder);
 
 	/**
@@ -91,7 +91,7 @@ public:
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Sets a given dial to be pointing in a specified region (0 to 2)
diff --git a/engines/titanic/true_talk/liftbot_script.cpp b/engines/titanic/true_talk/liftbot_script.cpp
index 2f079cbaac..027d597b08 100644
--- a/engines/titanic/true_talk/liftbot_script.cpp
+++ b/engines/titanic/true_talk/liftbot_script.cpp
@@ -56,7 +56,7 @@ void LiftbotScript::setupSentences() {
 	_entryCount = 0;
 }
 
-int LiftbotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) {
+int LiftbotScript::chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) {
 	switch (tag) {
 	case MKTAG('D', 'N', 'A', '1'):
 	case MKTAG('H', 'H', 'G', 'Q'):
@@ -85,7 +85,7 @@ int LiftbotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence
 	}
 }
 
-int LiftbotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int LiftbotScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	// TODO
 	return 0;
 }
@@ -95,12 +95,12 @@ int LiftbotScript::proc9() const {
 	return 0;
 }
 
-ScriptChangedResult LiftbotScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult LiftbotScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	warning("TODO");
 	return SCR_1;
 }
 
-int LiftbotScript::handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+int LiftbotScript::handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder) {
 	switch (tagId) {
 	case MKTAG('A', 'D', 'V', 'T'):
@@ -247,7 +247,7 @@ uint LiftbotScript::getDialsBitset() const {
 }
 
 
-int LiftbotScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int LiftbotScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	static const int ARRAY13[] = {
 		210724, 210735, 210746, 210757, 210758, 210759, 210760,
 		210761, 210762, 210725, 210726, 210727, 210728, 210729,
diff --git a/engines/titanic/true_talk/liftbot_script.h b/engines/titanic/true_talk/liftbot_script.h
index 55752e1df6..d2f5a3019b 100644
--- a/engines/titanic/true_talk/liftbot_script.h
+++ b/engines/titanic/true_talk/liftbot_script.h
@@ -53,21 +53,21 @@ public:
 	/**
 	 * Chooses and adds a conversation response based on a specified tag Id.
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag);
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag);
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	virtual int proc9() const;
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
-	virtual int handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+	virtual int handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder);
 
 	/**
@@ -88,7 +88,7 @@ public:
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Sets a given dial to be pointing in a specified region (0 to 2)
diff --git a/engines/titanic/true_talk/maitred_script.cpp b/engines/titanic/true_talk/maitred_script.cpp
index 7da541f0f7..57ae517db8 100644
--- a/engines/titanic/true_talk/maitred_script.cpp
+++ b/engines/titanic/true_talk/maitred_script.cpp
@@ -53,7 +53,7 @@ void MaitreDScript::setupSentences() {
 	_entryCount = 0;
 }
 
-int MaitreDScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) {
+int MaitreDScript::chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) {
 	if (tag == MKTAG('F', 'O', 'O', 'D') || tag == MKTAG('F', 'I', 'S', 'H') ||
 			tag == MKTAG('C', 'H', 'S', 'E')) {
 		addResponse(getDialogueId(260388));
@@ -65,17 +65,17 @@ int MaitreDScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence
 	return TTnpcScript::chooseResponse(roomScript, sentence, tag);
 }
 
-int MaitreDScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int MaitreDScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	// TODO
 	return 0;
 }
 
-ScriptChangedResult MaitreDScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult MaitreDScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	warning("TODO");
 	return SCR_1;
 }
 
-int MaitreDScript::handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+int MaitreDScript::handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder) {
 	switch (tagId) {
 	case MKTAG('A', 'D', 'V', 'T'):
@@ -301,7 +301,7 @@ int MaitreDScript::preResponse(uint id) {
 	return 0;
 }
 
-int MaitreDScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int MaitreDScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	warning("TODO");
 	return 0;
 }
diff --git a/engines/titanic/true_talk/maitred_script.h b/engines/titanic/true_talk/maitred_script.h
index 06fc6866ab..bed93fa6c1 100644
--- a/engines/titanic/true_talk/maitred_script.h
+++ b/engines/titanic/true_talk/maitred_script.h
@@ -63,19 +63,19 @@ public:
 	/**
 	 * Chooses and adds a conversation response based on a specified tag Id.
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag);
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag);
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
-	virtual int handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+	virtual int handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder);
 
 	/**
@@ -91,7 +91,7 @@ public:
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 };
 
 } // End of namespace Titanic
diff --git a/engines/titanic/true_talk/parrot_script.cpp b/engines/titanic/true_talk/parrot_script.cpp
index 96efc627c1..b09e74505c 100644
--- a/engines/titanic/true_talk/parrot_script.cpp
+++ b/engines/titanic/true_talk/parrot_script.cpp
@@ -41,7 +41,7 @@ void ParrotScript::setupSentences() {
 	_entryCount = 0;
 }
 
-int ParrotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) {
+int ParrotScript::chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) {
 	if (tag == MKTAG('B', 'Y', 'Z', 'A')) {
 		addResponse(getDialogueId(280246));
 		applyResponse();
@@ -51,7 +51,7 @@ int ParrotScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence,
 	}
 }
 
-int ParrotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int ParrotScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	if (processEntries(roomScript, sentence) == 2) {
 		int tagId = g_vm->_trueTalkManager->_quotes.find(sentence->_normalizedLine);
 		if (!tagId || chooseResponse(roomScript, sentence, tagId) != 2) {
@@ -63,7 +63,7 @@ int ParrotScript::process(TTroomScript *roomScript, TTsentence *sentence) {
 	return 2;
 }
 
-ScriptChangedResult ParrotScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult ParrotScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	if (id >= 280000 && id <= 280276) {
 		if (id == 280258) {
 			if (CTrueTalkManager::_currentNPC) {
@@ -103,7 +103,7 @@ ScriptChangedResult ParrotScript::scriptChanged(TTroomScript *roomScript, uint i
 	return (id == 3) ? SCR_2 : SCR_1;
 }
 
-int ParrotScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int ParrotScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	return 0;
 }
 
diff --git a/engines/titanic/true_talk/parrot_script.h b/engines/titanic/true_talk/parrot_script.h
index 7e473bf242..ec7bec7629 100644
--- a/engines/titanic/true_talk/parrot_script.h
+++ b/engines/titanic/true_talk/parrot_script.h
@@ -40,22 +40,22 @@ public:
 	/**
 	 * Chooses and adds a conversation response based on a specified tag Id.
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag);
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag);
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 };
 
 } // End of namespace Titanic
diff --git a/engines/titanic/true_talk/succubus_script.cpp b/engines/titanic/true_talk/succubus_script.cpp
index 9be779513f..e950f549b7 100644
--- a/engines/titanic/true_talk/succubus_script.cpp
+++ b/engines/titanic/true_talk/succubus_script.cpp
@@ -41,7 +41,7 @@ void SuccUBusScript::setupSentences() {
 	_entryCount = 0;
 }
 
-int SuccUBusScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) {
+int SuccUBusScript::chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) {
 	uint dialogueId = tag;
 
 	switch (tag) {
@@ -74,12 +74,12 @@ int SuccUBusScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentenc
 	}
 }
 
-int SuccUBusScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int SuccUBusScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	// TODO
 	return 0;
 }
 
-ScriptChangedResult SuccUBusScript::scriptChanged(TTroomScript *roomScript, uint id) {
+ScriptChangedResult SuccUBusScript::scriptChanged(const TTroomScript *roomScript, uint id) {
 	warning("TODO");
 	return SCR_1;
 }
@@ -89,7 +89,7 @@ int SuccUBusScript::updateState(uint oldId, uint newId, int index) {
 	return 0;
 }
 
-int SuccUBusScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int SuccUBusScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	warning("TODO");
 	return 0;
 }
diff --git a/engines/titanic/true_talk/succubus_script.h b/engines/titanic/true_talk/succubus_script.h
index 4ea85f1a92..541392eb30 100644
--- a/engines/titanic/true_talk/succubus_script.h
+++ b/engines/titanic/true_talk/succubus_script.h
@@ -42,17 +42,17 @@ public:
 	/**
 	 * Chooses and adds a conversation response based on a specified tag Id.
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag);
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag);
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id);
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id);
 
 	/**
 	 * Handles updating NPC state based on specified dialogue Ids and dial positions
@@ -62,7 +62,7 @@ public:
 	/**
 	 * Process a sentence fragment entry
 	 */
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 };
 
 } // End of namespace Titanic
diff --git a/engines/titanic/true_talk/tt_npc_script.cpp b/engines/titanic/true_talk/tt_npc_script.cpp
index b61b9d53e1..614b60747f 100644
--- a/engines/titanic/true_talk/tt_npc_script.cpp
+++ b/engines/titanic/true_talk/tt_npc_script.cpp
@@ -210,7 +210,7 @@ void TTnpcScript::addResponse(int id) {
 	TTscriptBase::addResponse(id);
 }
 
-int TTnpcScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) {
+int TTnpcScript::chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) {
 	for (uint idx = 0; idx < _responses.size(); ++idx) {
 		const TTnpcScriptResponse &response = _responses[idx];
 
@@ -231,7 +231,7 @@ int TTnpcScript::chooseResponse(TTroomScript *roomScript, TTsentence *sentence,
 	return 1;
 }
 
-int TTnpcScript::process(TTroomScript *roomScript, TTsentence *sentence) {
+int TTnpcScript::process(const TTroomScript *roomScript, const TTsentence *sentence) {
 	return processEntries(&_entries, _entryCount, roomScript, sentence);
 }
 
@@ -275,7 +275,7 @@ bool TTnpcScript::handleWord(uint id) const {
 	return true;
 }
 
-int TTnpcScript::handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+int TTnpcScript::handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder) {
 	if (_quotes.empty())
 		return 1;
@@ -395,7 +395,7 @@ const TTscriptMapping *TTnpcScript::getMapping(int index) {
 	return nullptr;
 }
 
-int TTnpcScript::doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence) {
+int TTnpcScript::doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence) {
 	return 0;
 }
 
@@ -698,7 +698,7 @@ CPetControl *TTnpcScript::getPetControl(CGameManager *gameManager) {
 	return nullptr;
 }
 
-int TTnpcScript::processEntries(const TTsentenceEntries *entries, uint entryCount, TTroomScript *roomScript, TTsentence *sentence) {
+int TTnpcScript::processEntries(const TTsentenceEntries *entries, uint entryCount, const TTroomScript *roomScript, const TTsentence *sentence) {
 	if (!entries)
 		return SS_1;
 	if (!entryCount)
@@ -769,7 +769,7 @@ int TTnpcScript::processEntries(const TTsentenceEntries *entries, uint entryCoun
 	return 1;
 }
 
-bool TTnpcScript::defaultProcess(TTroomScript *roomScript, TTsentence *sentence) {
+bool TTnpcScript::defaultProcess(const TTroomScript *roomScript, const TTsentence *sentence) {
 	uint remainder;
 	TTtreeResult results[32];
 	const TTstring &line = sentence->_normalizedLine;
@@ -803,7 +803,7 @@ TTscriptRange *TTnpcScript::findRange(uint id) {
 	return nullptr;
 }
 
-void TTnpcScript::checkItems(TTroomScript *roomScript, TTsentence *sentence) {
+void TTnpcScript::checkItems(const TTroomScript *roomScript, const TTsentence *sentence) {
 	_field2CC = 0;
 	++CTrueTalkManager::_v2;
 
diff --git a/engines/titanic/true_talk/tt_npc_script.h b/engines/titanic/true_talk/tt_npc_script.h
index ddb5b8ff64..21ab1be28b 100644
--- a/engines/titanic/true_talk/tt_npc_script.h
+++ b/engines/titanic/true_talk/tt_npc_script.h
@@ -59,12 +59,12 @@ public:
 	/**
 	 * Chooses and adds a conversation response based on a specified tag Id.
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag) = 0;
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag) = 0;
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence) = 0;
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence) = 0;
 
 	virtual int proc8() const = 0;
 	virtual int proc9() const = 0;
@@ -72,7 +72,7 @@ public:
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id) = 0;
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id) = 0;
 
 	virtual int proc11() const = 0;
 	virtual int proc12() const = 0;
@@ -168,18 +168,18 @@ protected:
 	/**
 	 * Scans through a list of sentence entries for a matching standardized response
 	 */
-	int processEntries(const TTsentenceEntries *entries, uint entryCount, TTroomScript *roomScript, TTsentence *sentence);
+	int processEntries(const TTsentenceEntries *entries, uint entryCount, const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Scans through a list of sentence entries for a matching standardized response
 	 */
-	int processEntries(TTroomScript *roomScript, TTsentence *sentence) {
+	int processEntries(const TTroomScript *roomScript, const TTsentence *sentence) {
 		return processEntries(&_entries, _entryCount, roomScript, sentence);
 	}
 
-	bool defaultProcess(TTroomScript *roomScript, TTsentence *sentence);
+	bool defaultProcess(const TTroomScript *roomScript, const TTsentence *sentence);
 
-	void checkItems(TTroomScript *roomScript, TTsentence *sentence);
+	void checkItems(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Adds a random conversation response
@@ -224,12 +224,12 @@ public:
 	 * This default implementation does a lookup into a list of known tags,
 	 * and chooses a random dialogue Id from the available ones for that tag
 	 */
-	virtual int chooseResponse(TTroomScript *roomScript, TTsentence *sentence, uint tag);
+	virtual int chooseResponse(const TTroomScript *roomScript, const TTsentence *sentence, uint tag);
 
 	/**
 	 * Does NPC specific processing of the parsed sentence
 	 */
-	virtual int process(TTroomScript *roomScript, TTsentence *sentence);
+	virtual int process(const TTroomScript *roomScript, const TTsentence *sentence);
 
 	virtual int proc8() const;
 	virtual int proc9() const;
@@ -237,7 +237,7 @@ public:
 	/**
 	 * Called when the script/id changes
 	 */
-	virtual ScriptChangedResult scriptChanged(TTroomScript *roomScript, uint id) {
+	virtual ScriptChangedResult scriptChanged(const TTroomScript *roomScript, uint id) {
 		return SCR_2;
 	}
 
@@ -256,7 +256,7 @@ public:
 	 */
 	virtual bool handleWord(uint id) const;
 
-	virtual int handleQuote(TTroomScript *roomScript, TTsentence *sentence,
+	virtual int handleQuote(const TTroomScript *roomScript, const TTsentence *sentence,
 		uint val, uint tagId, uint remainder);
 
 	/**
@@ -287,12 +287,12 @@ public:
 	virtual uint getDialsBitset() const { return 0; }
 	
 	virtual const TTscriptMapping *getMapping(int index);
-	virtual int doSentenceEntry(int val1, const int *srcIdP, TTroomScript *roomScript, TTsentence *sentence);
+	virtual int doSentenceEntry(int val1, const int *srcIdP, const TTroomScript *roomScript, const TTsentence *sentence);
 
 	/**
 	 * Handles any post-response NPC processing
 	 */
-	virtual void postResponse(int v1, const TTsentenceEntry *entry, TTroomScript *roomScript, TTsentence *sentence) {}
+	virtual void postResponse(int v1, const TTsentenceEntry *entry, const TTroomScript *roomScript, const TTsentence *sentence) {}
 	
 	virtual void save(SimpleFile *file);
 	virtual void load(SimpleFile *file);
diff --git a/engines/titanic/true_talk/tt_sentence.cpp b/engines/titanic/true_talk/tt_sentence.cpp
index 467f6a188a..6a8e74d976 100644
--- a/engines/titanic/true_talk/tt_sentence.cpp
+++ b/engines/titanic/true_talk/tt_sentence.cpp
@@ -108,19 +108,19 @@ int TTsentence::storeVocabHit(TTword *word) {
 }
 
 bool TTsentence::fn1(const CString &str, int wordId1, const CString &str1, const CString &str2,
-		const CString &str3, int wordId2, int val, int val2, const TTconceptNode *node) {
+		const CString &str3, int wordId2, int val, int val2, const TTconceptNode *node) const {
 	// TODO
 	return false;
 }
 
 bool TTsentence::fn3(const CString &str1, const CString &str2, const CString &str3,
 		const CString &str4, const CString &str5, const CString &str6,
-		int val, int val2, const TTconceptNode *node) {
+		int val, int val2, const TTconceptNode *node) const {
 	// TODO
 	return false;
 }
 
-bool TTsentence::fn2(int slotIndex, const TTstring &str, TTconceptNode *conceptNode) {
+bool TTsentence::fn2(int slotIndex, const TTstring &str, const TTconceptNode *conceptNode) const {
 	if (!conceptNode)
 		conceptNode = &_sentenceConcept;
 	TTconcept *concept = getFrameSlot(slotIndex, conceptNode);
@@ -199,7 +199,7 @@ exit:
 	return abortFlag;
 }
 
-bool TTsentence::fn4(int mode, int wordId, TTconceptNode *node) {
+bool TTsentence::fn4(int mode, int wordId, const TTconceptNode *node) const {
 	if (!node)
 		node = &_sentenceConcept;
 
@@ -256,7 +256,7 @@ int TTsentence::is1C(int val, const TTconceptNode *node) const {
 	return node->_field1C == val;
 }
 
-bool TTsentence::isConcept34(int slotIndex, TTconceptNode *node) {
+bool TTsentence::isConcept34(int slotIndex, const TTconceptNode *node) const {
 	TTconcept *concept = getFrameEntry(slotIndex, node);
 	return concept && concept->getState();
 }
diff --git a/engines/titanic/true_talk/tt_sentence.h b/engines/titanic/true_talk/tt_sentence.h
index 2900a4d4b3..8cecaed4f2 100644
--- a/engines/titanic/true_talk/tt_sentence.h
+++ b/engines/titanic/true_talk/tt_sentence.h
@@ -109,14 +109,14 @@ public:
 	int storeVocabHit(TTword *word);
 
 	bool fn1(const CString &str, int wordId1, const CString &str1, const CString &str2,
-		const CString &str3, int wordId2, int val, int val2, const TTconceptNode *node);
+		const CString &str3, int wordId2, int val, int val2, const TTconceptNode *node) const;
 	bool fn3(const CString &str1, const CString &str2, const CString &str3,
 		const CString &str4, const CString &str5, const CString &str6,
-		int val, int val2, const TTconceptNode *node);
-	bool fn2(int slotIndex, const TTstring &str, TTconceptNode *conceptNode);
-	bool fn4(int mode, int wordId, TTconceptNode *node);
+		int val, int val2, const TTconceptNode *node) const;
+	bool fn2(int slotIndex, const TTstring &str, const TTconceptNode *conceptNode) const;
+	bool fn4(int mode, int wordId, const TTconceptNode *node) const;
 
-	bool isConcept34(int slotIndex, TTconceptNode *node = nullptr);
+	bool isConcept34(int slotIndex, const TTconceptNode *node = nullptr) const;
 
 	bool localWord(const char *str) const;