SUPERNOVA: Removes global nullObject

Before nullObject was a static member of Object class and now a member
of GameManager. Also the Inventory constructor was extended for taking a
pointer to the nullObject that Invetory::get() returns if no Object was
found.

4 files changed, 27 insertions, 25 deletions

diff --git a/engines/supernova/msn_def.h b/engines/supernova/msn_def.h
index 3f1c69bce5..6ce16b8283 100644
--- a/engines/supernova/msn_def.h
+++ b/engines/supernova/msn_def.h
@@ -304,8 +304,6 @@ ObjectType &operator&=(ObjectType &a, ObjectType b);
 ObjectType &operator^=(ObjectType &a, ObjectType b);
 
 struct Object {
-	static const Object nullObject;
-
 	Object()
 		: _name(kNoString)
 		, _description(kStringDefaultDescription)
@@ -332,12 +330,6 @@ struct Object {
 		, _direction(direction)
 	{}
 
-	static void setObjectNull(Object *&obj) {
-		obj = const_cast<Object *>(&nullObject);
-	}
-	static bool isNullObject(Object *obj) {
-		return obj == &nullObject;
-	}
 	void resetProperty(ObjectType type = NULLTYPE) {
 		_type = type;
 	}
diff --git a/engines/supernova/state.cpp b/engines/supernova/state.cpp
index 51e0ee5c73..00a35055b7 100644
--- a/engines/supernova/state.cpp
+++ b/engines/supernova/state.cpp
@@ -196,7 +196,7 @@ Object *Inventory::get(int index) const {
 	if (index < _numObjects)
 		return _inventory[index];
 
-	return const_cast<Object *>(&Object::nullObject);
+	return _nullObject;
 }
 
 Object *Inventory::get(ObjectId id) const {
@@ -205,7 +205,7 @@ Object *Inventory::get(ObjectId id) const {
 			return _inventory[i];
 	}
 
-	return const_cast<Object *>(&Object::nullObject);
+	return _nullObject;
 }
 
 
@@ -288,7 +288,7 @@ StringId GameManager::guiStatusCommands[] = {
 };
 
 GameManager::GameManager(SupernovaEngine *vm, Sound *sound)
-	: _inventory(_inventoryScroll)
+	: _inventory(&_nullObject, _inventoryScroll)
 	, _vm(vm)
 	, _sound(sound) {
 	initRooms();
@@ -354,11 +354,10 @@ void GameManager::destroyRooms() {
 	delete _rooms[OUTRO];
 }
 
-
 void GameManager::initState() {
-	Object::setObjectNull(_currentInputObject);
-	Object::setObjectNull(_inputObject[0]);
-	Object::setObjectNull(_inputObject[1]);
+	_currentInputObject = &_nullObject;
+	_inputObject[0] = &_nullObject;
+	_inputObject[1] = &_nullObject;
 	_inputVerb = ACTION_WALK;
 	_processInput = false;
 	_guiEnabled = true;
@@ -611,8 +610,8 @@ void GameManager::processInput(Common::KeyState &state) {
 }
 
 void GameManager::resetInputState() {
-	Object::setObjectNull(_inputObject[0]);
-	Object::setObjectNull(_inputObject[1]);
+	setObjectNull(_inputObject[0]);
+	setObjectNull(_inputObject[1]);
 	_inputVerb = ACTION_WALK;
 	_processInput = false;
 	_mouseClicked = false;
@@ -659,7 +658,7 @@ void GameManager::processInput() {
 		case onInventory:
 			// Fallthrough
 			if (_inputVerb == ACTION_GIVE || _inputVerb == ACTION_USE) {
-				if (Object::isNullObject(_inputObject[0])) {
+				if (isNullObject(_inputObject[0])) {
 					_inputObject[0] = _currentInputObject;
 					if (!_inputObject[0]->hasProperty(COMBINABLE))
 						_processInput = true;
@@ -669,7 +668,7 @@ void GameManager::processInput() {
 				}
 			} else {
 				_inputObject[0] = _currentInputObject;
-				if (!Object::isNullObject(_currentInputObject))
+				if (!isNullObject(_currentInputObject))
 					_processInput = true;
 			}
 			break;
@@ -696,7 +695,7 @@ void GameManager::processInput() {
 			return;
 		}
 
-		if (Object::isNullObject(_currentInputObject))
+		if (isNullObject(_currentInputObject))
 			return;
 
 		if (mouseLocation == onObject || mouseLocation == onInventory) {
@@ -775,7 +774,7 @@ void GameManager::processInput() {
 				break;
 			}
 
-			Object::setObjectNull(_currentInputObject);
+			setObjectNull(_currentInputObject);
 
 			_mouseField = field;
 			if (_mouseField >= 0 && _mouseField < 256)
@@ -814,6 +813,14 @@ void GameManager::processInput() {
 	}
 }
 
+void GameManager::setObjectNull(Object *&obj) {
+	obj = &_nullObject;
+}
+
+bool GameManager::isNullObject(Object *obj) {
+	return obj == &_nullObject;
+}
+
 void GameManager::corridorOnEntrance() {
 	if (_state._corridorSearch)
 		busted(0);
@@ -1874,7 +1881,7 @@ void GameManager::drawStatus() {
 	_vm->renderBox(0, 140, 320, 9, kColorWhite25);
 	_vm->renderText(_vm->getGameString(guiStatusCommands[index]), 1, 141, kColorDarkGreen);
 
-	if (Object::isNullObject(_inputObject[0]))
+	if (isNullObject(_inputObject[0]))
 		_vm->renderText(_currentInputObject->_name);
 	else {
 		_vm->renderText(_inputObject[0]->_name);
diff --git a/engines/supernova/state.h b/engines/supernova/state.h
index e3de0eb94b..1b885ccbdd 100644
--- a/engines/supernova/state.h
+++ b/engines/supernova/state.h
@@ -65,8 +65,9 @@ struct GameState {
 
 class Inventory {
 public:
-	Inventory(int &inventoryScroll)
+	Inventory(Object *nullObject, int &inventoryScroll)
 		: _numObjects(0)
+		, _nullObject(nullObject)
 		, _inventoryScroll(inventoryScroll)
 	{}
 
@@ -79,6 +80,7 @@ public:
 
 private:
 	Object *_inventory[kMaxCarry];
+	Object *_nullObject;
 	int &_inventoryScroll;
 	int _numObjects;
 };
@@ -154,6 +156,7 @@ public:
 	bool _animationEnabled;
 	byte _roomBrightness;
 	Action _inputVerb;
+	Object _nullObject;
 	Object *_currentInputObject;
 	Object *_inputObject[2];
 	bool _waitEvent;
@@ -175,6 +178,8 @@ public:
 	byte _rowsStart[6];
 
 	void takeObject(Object &obj);
+	void setObjectNull(Object *&obj);
+	bool isNullObject(Object *obj);
 
 	void initState();
 	void initRooms();
diff --git a/engines/supernova/supernova.cpp b/engines/supernova/supernova.cpp
index 035238b3ac..c47e476de7 100644
--- a/engines/supernova/supernova.cpp
+++ b/engines/supernova/supernova.cpp
@@ -49,8 +49,6 @@
 
 namespace Supernova {
 
-const Object Object::nullObject;
-
 ObjectType operator|(ObjectType a, ObjectType b) {
 	return static_cast<ObjectType>(+a | +b);
 }