fix(Core/Movement): Allow MoveFollow to not inherit speed of the target (#21711)

src/server/game/AI/ScriptedAI/ScriptedFollowerAI.cpp

@@ -264,7 +264,7 @@ void FollowerAI::MovementInform(uint32 motionType, uint32 pointId)
     }
 }
 
-void FollowerAI::StartFollow(Player* player, uint32 factionForFollower, const Quest* quest)
+void FollowerAI::StartFollow(Player* player, uint32 factionForFollower, const Quest* quest, bool inheritWalkState, bool inheritSpeed)
 {
     if (me->GetVictim())
     {
@@ -297,7 +297,7 @@ void FollowerAI::StartFollow(Player* player, uint32 factionForFollower, const Qu
 
     AddFollowState(STATE_FOLLOW_INPROGRESS);
 
-    me->GetMotionMaster()->MoveFollow(player, PET_FOLLOW_DIST, PET_FOLLOW_ANGLE);
+    me->GetMotionMaster()->MoveFollow(player, PET_FOLLOW_DIST, PET_FOLLOW_ANGLE, MOTION_SLOT_ACTIVE, inheritWalkState, inheritSpeed);
 
     LOG_DEBUG("scripts.ai", "FollowerAI start follow {} ({})", player->GetName(), m_uiLeaderGUID.ToString());
 }

src/server/game/AI/ScriptedAI/ScriptedFollowerAI.h

@@ -55,7 +55,7 @@ public:
     void UpdateAI(uint32) override;                        //the "internal" update, calls UpdateFollowerAI()
     virtual void UpdateFollowerAI(uint32);        //used when it's needed to add code in update (abilities, scripted events, etc)
 
-    void StartFollow(Player* player, uint32 factionForFollower = 0, const Quest* quest = nullptr);
+    void StartFollow(Player* player, uint32 factionForFollower = 0, const Quest* quest = nullptr, bool inheritWalkState = true, bool inheritSpeed = true);
 
     void SetFollowPaused(bool bPaused);                 //if special event require follow mode to hold/resume during the follow
     void SetFollowComplete(bool bWithEndEvent = false);

src/server/game/Movement/MotionMaster.cpp

@@ -277,7 +277,7 @@ void MotionMaster::MoveTargetedHome(bool walk /*= false*/)
         if (target)
         {
             LOG_DEBUG("movement.motionmaster", "Following {} ({})", target->IsPlayer() ? "player" : "creature", target->GetGUID().ToString());
-            Mutate(new FollowMovementGenerator<Creature>(target, PET_FOLLOW_DIST, _owner->GetFollowAngle(),true), MOTION_SLOT_ACTIVE);
+            Mutate(new FollowMovementGenerator<Creature>(target, PET_FOLLOW_DIST, _owner->GetFollowAngle(), true, true), MOTION_SLOT_ACTIVE);
         }
     }
     else
@@ -406,7 +406,7 @@ void MotionMaster::MoveCircleTarget(Unit* target)
 /**
  * @brief The unit will follow this target. Doesn't work with UNIT_FLAG_DISABLE_MOVE
  */
-void MotionMaster::MoveFollow(Unit* target, float dist, float angle, MovementSlot slot, bool inheritWalkState)
+void MotionMaster::MoveFollow(Unit* target, float dist, float angle, MovementSlot slot, bool inheritWalkState, bool inheritSpeed)
 {
     // ignore movement request if target not exist
     if (!target || target == _owner || _owner->HasUnitFlag(UNIT_FLAG_DISABLE_MOVE))
@@ -419,13 +419,13 @@ void MotionMaster::MoveFollow(Unit* target, float dist, float angle, MovementSlo
     {
         LOG_DEBUG("movement.motionmaster", "Player ({}) follow to {} ({})",
             _owner->GetGUID().ToString(), target->IsPlayer() ? "player" : "creature", target->GetGUID().ToString());
-        Mutate(new FollowMovementGenerator<Player>(target, dist, angle, inheritWalkState), slot);
+        Mutate(new FollowMovementGenerator<Player>(target, dist, angle, inheritWalkState, inheritSpeed), slot);
     }
     else
     {
         LOG_DEBUG("movement.motionmaster", "Creature ({}) follow to {} ({})",
             _owner->GetGUID().ToString(), target->IsPlayer() ? "player" : "creature", target->GetGUID().ToString());
-        Mutate(new FollowMovementGenerator<Creature>(target, dist, angle, inheritWalkState), slot);
+        Mutate(new FollowMovementGenerator<Creature>(target, dist, angle, inheritWalkState, inheritSpeed), slot);
     }
 }
 

src/server/game/Movement/MotionMaster.h

@@ -201,7 +201,7 @@ public:
     void MoveIdle();
     void MoveTargetedHome(bool walk = false);
     void MoveRandom(float wanderDistance = 0.0f);
-    void MoveFollow(Unit* target, float dist, float angle, MovementSlot slot = MOTION_SLOT_ACTIVE, bool inheritWalkState = true);
+    void MoveFollow(Unit* target, float dist, float angle, MovementSlot slot = MOTION_SLOT_ACTIVE, bool inheritWalkState = true, bool inheritSpeed = true);
     void MoveChase(Unit* target, std::optional<ChaseRange> dist = {}, std::optional<ChaseAngle> angle = {});
     void MoveChase(Unit* target, float dist, float angle) { MoveChase(target, ChaseRange(dist), ChaseAngle(angle)); }
     void MoveChase(Unit* target, float dist) { MoveChase(target, ChaseRange(dist)); }

src/server/game/Movement/MovementGenerators/TargetedMovementGenerator.cpp

@@ -539,8 +539,9 @@ bool FollowMovementGenerator<T>::DoUpdate(T* owner, uint32 time_diff)
         if (_inheritWalkState)
             init.SetWalk(target->IsWalking() || target->movespline->isWalking());
 
-        if (Optional<float> velocity = GetVelocity(owner, target, i_path->GetActualEndPosition(), owner->IsGuardian()))
+        if (_inheritSpeed)
-            init.SetVelocity(*velocity);
+            if (Optional<float> velocity = GetVelocity(owner, target, i_path->GetActualEndPosition(), owner->IsGuardian()))
+                init.SetVelocity(*velocity);
         init.Launch();
     }
 

src/server/game/Movement/MovementGenerators/TargetedMovementGenerator.h

@@ -75,8 +75,8 @@ template<class T>
 class FollowMovementGenerator : public MovementGeneratorMedium<T, FollowMovementGenerator<T>>, public TargetedMovementGeneratorBase
 {
 public:
-    FollowMovementGenerator(Unit* target, float range, ChaseAngle angle, bool inheritWalkState)
+    FollowMovementGenerator(Unit* target, float range, ChaseAngle angle, bool inheritWalkState, bool inheritSpeed)
-        : TargetedMovementGeneratorBase(target), i_path(nullptr), i_recheckPredictedDistanceTimer(0), i_recheckPredictedDistance(false), _range(range), _angle(angle),_inheritWalkState(inheritWalkState) {}
+        : TargetedMovementGeneratorBase(target), i_path(nullptr), i_recheckPredictedDistanceTimer(0), i_recheckPredictedDistance(false), _range(range), _angle(angle),_inheritWalkState(inheritWalkState), _inheritSpeed(inheritSpeed) {}
     ~FollowMovementGenerator() { }
 
     MovementGeneratorType GetMovementGeneratorType() { return FOLLOW_MOTION_TYPE; }
@@ -108,6 +108,7 @@ private:
     float _range;
     ChaseAngle _angle;
     bool _inheritWalkState;
+    bool _inheritSpeed;
 };
 
 #endif