Core/AI: Make critters flee as soon as engaged in combat and make them evade after they stop running in fear (#24320)

* Core/AI: Make critters flee as soon as engaged in combat and make them evade after they stop running in fear

* Warning and no-pch build fix

src/server/game/AI/CoreAI/PassiveAI.cpp

@@ -17,6 +17,7 @@
 
 #include "PassiveAI.h"
 #include "Creature.h"
+#include "MovementDefines.h"
 
 PassiveAI::PassiveAI(Creature* creature) : CreatureAI(creature)
 {
@@ -79,12 +80,18 @@ void PossessedAI::KilledUnit(Unit* victim)
         victim->RemoveFlag(UNIT_DYNAMIC_FLAGS, UNIT_DYNFLAG_LOOTABLE);
 }
 
-void CritterAI::DamageTaken(Unit* /*done_by*/, uint32&)
+void CritterAI::JustEngagedWith(Unit* /*who*/)
 {
     if (!me->HasUnitState(UNIT_STATE_FLEEING))
         me->SetControlled(true, UNIT_STATE_FLEEING);
 }
 
+void CritterAI::OnMovementGeneratorFinalized(MovementGeneratorType type)
+{
+    if (type == TIMED_FLEEING_MOTION_TYPE)
+        EnterEvadeMode(EVADE_REASON_OTHER);
+}
+
 void CritterAI::EnterEvadeMode(EvadeReason why)
 {
     if (me->HasUnitState(UNIT_STATE_FLEEING))

src/server/game/AI/CoreAI/PassiveAI.h

@@ -73,9 +73,11 @@ class TC_GAME_API CritterAI : public PassiveAI
     public:
         explicit CritterAI(Creature* creature) : PassiveAI(creature) { }
 
-        void DamageTaken(Unit* done_by, uint32& /*damage*/) override;
+        void JustEngagedWith(Unit* /*who*/) override;
         void EnterEvadeMode(EvadeReason why) override;
 
+        void OnMovementGeneratorFinalized(MovementGeneratorType type) override;
+
         static int32 Permissible(Creature const* creature);
 };
 

src/server/game/AI/CoreAI/UnitAI.h

@@ -42,6 +42,7 @@ class SpellInfo;
 class Unit;
 struct AISpellInfoType;
 enum DamageEffectType : uint8;
+enum MovementGeneratorType : uint8;
 enum SpellEffIndex : uint8;
 
 //Selection method used by SelectTarget
@@ -328,6 +329,8 @@ class TC_GAME_API UnitAI
         // Called when a game event starts or ends
         virtual void OnGameEvent(bool /*start*/, uint16 /*eventId*/) { }
 
+        virtual void OnMovementGeneratorFinalized(MovementGeneratorType /*type*/) { }
+
         virtual std::string GetDebugInfo() const;
 
     private:

src/server/game/Movement/MotionMaster.cpp

@@ -1142,7 +1142,10 @@ void MotionMaster::DirectAdd(MovementGenerator* movement, MovementSlot slot/* =
     {
         case MOTION_SLOT_DEFAULT:
             if (_defaultGenerator)
+            {
                 _defaultGenerator->Finalize(_owner, _generators.empty(), false);
+                _defaultGenerator->NotifyAIOnFinalize(_owner);
+            }
 
             _defaultGenerator = MovementGeneratorPointer(movement);
             if (IsStatic(movement))
@@ -1187,6 +1190,7 @@ void MotionMaster::Delete(MovementGenerator* movement, bool active, bool movemen
         movement->Priority, movement->Flags, movement->BaseUnitState, movement->GetMovementGeneratorType(), _owner->GetGUID().ToString().c_str());
 
     movement->Finalize(_owner, active, movementInform);
+    movement->NotifyAIOnFinalize(_owner);
     ClearBaseUnitState(movement);
     MovementGeneratorPointerDeleter(movement);
 }
@@ -1197,6 +1201,7 @@ void MotionMaster::DeleteDefault(bool active, bool movementInform)
         _defaultGenerator->Priority, _defaultGenerator->Flags, _defaultGenerator->BaseUnitState, _defaultGenerator->GetMovementGeneratorType(), _owner->GetGUID().ToString().c_str());
 
     _defaultGenerator->Finalize(_owner, active, movementInform);
+    _defaultGenerator->NotifyAIOnFinalize(_owner);
     _defaultGenerator = MovementGeneratorPointer(GetIdleMovementGenerator());
     AddFlag(MOTIONMASTER_FLAG_STATIC_INITIALIZATION_PENDING);
 }

src/server/game/Movement/MovementGenerator.cpp

@@ -21,6 +21,7 @@
 #include "MovementDefines.h"
 #include "PathGenerator.h"
 #include "RandomMovementGenerator.h"
+#include "UnitAI.h"
 #include "WaypointMovementGenerator.h"
 
 MovementGenerator::~MovementGenerator() { }
@@ -57,3 +58,9 @@ MovementGenerator* WaypointMovementFactory::Create(Unit* /*object*/) const
 {
     return new WaypointMovementGenerator<Creature>();
 }
+
+void MovementGenerator::NotifyAIOnFinalize(Unit* object)
+{
+    if (UnitAI* ai = object->GetAI())
+        ai->OnMovementGeneratorFinalized(GetMovementGeneratorType());
+}

src/server/game/Movement/MovementGenerator.h

@@ -69,6 +69,8 @@ class TC_GAME_API MovementGenerator
         // used by Evade code for select point to evade with expected restart default movement
         virtual bool GetResetPosition(Unit*, float&/* x*/, float&/* y*/, float&/* z*/) { return false; }
 
+        virtual void NotifyAIOnFinalize(Unit*);
+
         void AddFlag(uint16 const flag) { Flags |= flag; }
         bool HasFlag(uint16 const flag) const { return (Flags & flag) != 0; }
         void RemoveFlag(uint16 const flag) { Flags &= ~flag; }