amend reaction fire behaviour

allow xcom soldiers to spin and shoot at aggressors

src/Battlescape/BattlescapeGame.cpp

@@ -105,6 +105,7 @@ void BattlescapeGame::think()
 		// it's a non player side (ALIENS or CIVILIANS)
 		if (_save->getSide() != FACTION_PLAYER)
 		{
+			_save->resetUnitHitStates();
 			if (!_debugPlay)
 			{
 				if (_save->getSelectedUnit())

src/Battlescape/TileEngine.cpp

@@ -857,7 +857,24 @@ std::vector<std::pair<BattleUnit *, int> > TileEngine::getSpottingUnits(BattleUn
 				Position originVoxel = getOriginVoxel(falseAction, 0);
 				Position targetVoxel;
 				AIModule *ai = (*i)->getAIModule();
-				bool gotHit = (ai != 0 && ai->getWasHitBy(unit->getId()));
+
+				// Inquisitor's note regarding 'gotHit' variable
+				// in vanilla, the 'hitState' flag is the only part of this equation that comes into play.
+				// any time a unit takes damage, this flag is set, then it would be reset by a call to
+				// a function analogous to SavedBattleGame::resetUnitHitStates(), any time:
+				// 1: a unit was selected by being clicked on.
+				// 2: either "next unit" button was pressed.
+				// 3: the inventory screen was accessed. (i didn't look too far into this one, it's possible it's only called in the pre-mission equip screen)
+				// 4: the same place where we call it, immediately before every move the AI makes.
+				// this flag is responsible for units turning around to respond to hits, and is in keeping with the details listed on http://www.ufopaedia.org/index.php/Reaction_fire_triggers
+				// we've gone for a slightly different implementation: AI units keep a list of which units have hit them and don't forget until the end of the player's turn.
+				// this method is in keeping with the spirit of the original feature, but much less exploitable by players.
+				// the hitState flag in our implementation allows player units to turn and react as they did in the original, (which is far less cumbersome than giving them all an AI module)
+				// we don't extend the same "enhanced aggressor memory" courtesy to players, because in the original, they could only turn and react to damage immediately after it happened.
+				// this is because as much as we want the player's soldiers dead, we don't want them to feel like we're being unfair about it.
+
+				bool gotHit = (ai != 0 && ai->getWasHitBy(unit->getId())) || (ai == 0 && (*i)->getHitState());
+
 					// can actually see the target Tile, or we got hit
 				if (((*i)->checkViewSector(unit->getPosition()) || gotHit) &&
 					// can actually target the unit

src/Savegame/BattleUnit.cpp

@@ -52,7 +52,7 @@ BattleUnit::BattleUnit(Soldier *soldier, int depth) :
 	_verticalDirection(0), _status(STATUS_STANDING), _walkPhase(0), _fallPhase(0), _kneeled(false), _floating(false),
 	_dontReselect(false), _fire(0), _currentAIState(0), _visible(false), _cacheInvalid(true),
 	_expBravery(0), _expReactions(0), _expFiring(0), _expThrowing(0), _expPsiSkill(0), _expPsiStrength(0), _expMelee(0),
-	_motionPoints(0), _kills(0), _hitByFire(false), _moraleRestored(0), _coverReserve(0), _charging(0), _turnsSinceSpotted(255),
+	_motionPoints(0), _kills(0), _hitByFire(false), _hitByAnything(false), _moraleRestored(0), _coverReserve(0), _charging(0), _turnsSinceSpotted(255),
 	_statistics(), _murdererId(0), _mindControllerID(0), _fatalShotSide(SIDE_FRONT), _fatalShotBodyPart(BODYPART_HEAD),
 	_geoscapeSoldier(soldier), _unitRules(0), _rankInt(0), _turretType(-1), _hidingForTurn(false), _respawn(false)
 {
@@ -164,7 +164,7 @@ BattleUnit::BattleUnit(Unit *unit, UnitFaction faction, int id, Armor *armor, St
 	_toDirectionTurret(0),  _verticalDirection(0), _status(STATUS_STANDING), _walkPhase(0),
 	_fallPhase(0), _kneeled(false), _floating(false), _dontReselect(false), _fire(0), _currentAIState(0),
 	_visible(false), _cacheInvalid(true), _expBravery(0), _expReactions(0), _expFiring(0),
-	_expThrowing(0), _expPsiSkill(0), _expPsiStrength(0), _expMelee(0), _motionPoints(0), _kills(0), _hitByFire(false),
+	_expThrowing(0), _expPsiSkill(0), _expPsiStrength(0), _expMelee(0), _motionPoints(0), _kills(0), _hitByFire(false), _hitByAnything(false),
 	_moraleRestored(0), _coverReserve(0), _charging(0), _turnsSinceSpotted(255),
 	_statistics(), _murdererId(0), _mindControllerID(0), _fatalShotSide(SIDE_FRONT),
 	_fatalShotBodyPart(BODYPART_HEAD), _armor(armor),  _geoscapeSoldier(0), _unitRules(unit),
@@ -1079,7 +1079,7 @@ int BattleUnit::damage(Position relative, int power, ItemDamageType type, bool i
 {
 	UnitSide side = SIDE_FRONT;
 	UnitBodyPart bodypart = BODYPART_TORSO;
-
+	_hitByAnything = true;
 	if (power <= 0)
 	{
 		return 0;
@@ -1639,6 +1639,11 @@ void BattleUnit::prepareNewTurn(bool fullProcess)
 	if (_faction != _originalFaction)
 	{
 		_faction = _originalFaction;
+		if (_faction == FACTION_PLAYER && _currentAIState)
+		{
+			delete _currentAIState;
+			_currentAIState = 0;
+		}
 	}
 	else
 	{
@@ -3242,13 +3247,36 @@ int BattleUnit::getMindControllerId() const
 	return _mindControllerID;
 }
 
+/**
+ * Get the unit's total firing xp for this mission.
+ */
 int BattleUnit::getFiringXP() const
 {
 	return _expFiring;
 }
+
+/**
+ * Artificially alter a unit's firing xp. (used for shotguns)
+ */
 void BattleUnit::nerfFiringXP(int newXP)
 {
 	_expFiring = newXP;
 }
 
+/**
+ * Was this unit just hit?
+ */
+bool BattleUnit::getHitState()
+{
+	return _hitByAnything;
+}
+
+/**
+ * reset the unit hit state.
+ */
+void BattleUnit::resetHitState()
+{
+	_hitByAnything = false;
+}
+
 }

src/Savegame/BattleUnit.h

@@ -91,7 +91,7 @@ class BattleUnit
 	int _motionPoints;
 	int _kills;
 	int _faceDirection; // used only during strafeing moves
-	bool _hitByFire;
+	bool _hitByFire, _hitByAnything;
 	int _moraleRestored;
 	int _coverReserve;
 	BattleUnit *_charging;
@@ -494,9 +494,15 @@ class BattleUnit
 	void setMindControllerId(int id);
 	/// Get the unit mind controller's id.
 	int getMindControllerId() const;
+	/// Get the unit's total firing xp for this mission.
 	int getFiringXP() const;
+	/// Artificially alter a unit's firing xp. (used for shotguns)
 	void nerfFiringXP(int newXP);
-
+	/// Was this unit just hit?
+	bool getHitState();
+	/// reset the unit hit state.
+	void resetHitState();
+
 };
 
 }

src/Savegame/SavedBattleGame.cpp

@@ -2059,4 +2059,15 @@ bool SavedBattleGame::isItemUsable(RuleItem *item) const
 	return true;
 }
 
+/**
+ * Resets all unit hit state flags.
+ */
+void SavedBattleGame::resetUnitHitStates()
+{
+	for (std::vector<BattleUnit*>::iterator i = _units.begin(); i != _units.end(); ++i)
+	{
+		(*i)->resetHitState();
+	}
+}
+
 }

src/Savegame/SavedBattleGame.h

@@ -289,9 +289,12 @@ class SavedBattleGame
 	void setChronoTrigger(ChronoTrigger trigger);
 	/// Sets the turn to start the aliens cheating.
 	void setCheatTurn(int turn);
+	/// Check whether the battle has actually commenced or not.
 	bool isBeforeGame() const;
 	/// Checks if an item is usable on this map.
 	bool isItemUsable(RuleItem *item) const;
+	/// Reset all the unit hit state flags.
+	void resetUnitHitStates();
 };
 
 }