Core/Movement: implement a parameter override to force 2D wandering

MovePositionToFirstCollision implementation can cause Z coordinate modification, making flying units wander up and down unintentionally

Author: ccrs

src/server/game/Movement/MotionMaster.cpp

@@ -594,12 +594,12 @@ void MotionMaster::MoveTargetedHome()
     }
 }
 
-void MotionMaster::MoveRandom(float wanderDistance)
+void MotionMaster::MoveRandom(float wanderDistance/* = 0.0f*/, bool force2DPositionRelocation/* = false*/)
 {
     if (_owner->GetTypeId() == TYPEID_UNIT)
     {
         TC_LOG_DEBUG("movement.motionmaster", "MotionMaster::MoveRandom: '{}', started random movement (spawnDist: {})", _owner->GetGUID().ToString(), wanderDistance);
-        Add(new RandomMovementGenerator<Creature>(wanderDistance), MOTION_SLOT_DEFAULT);
+        Add(new RandomMovementGenerator<Creature>(wanderDistance, force2DPositionRelocation), MOTION_SLOT_DEFAULT);
     }
 }
 

src/server/game/Movement/MotionMaster.h

@@ -153,7 +153,7 @@ class TC_GAME_API MotionMaster
 
         void MoveIdle();
         void MoveTargetedHome();
-        void MoveRandom(float wanderDistance = 0.0f);
+        void MoveRandom(float wanderDistance = 0.0f, bool force2DPositionRelocation = false);
         void MoveFollow(Unit* target, float dist, ChaseAngle angle, MovementSlot slot = MOTION_SLOT_ACTIVE);
         void MoveChase(Unit* target, Optional<ChaseRange> dist = {}, Optional<ChaseAngle> angle = {});
         void MoveChase(Unit* target, float dist, float angle) { MoveChase(target, ChaseRange(dist), ChaseAngle(angle)); }

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

@@ -25,15 +25,15 @@
 #include "Random.h"
 
 template<class T>
-RandomMovementGenerator<T>::RandomMovementGenerator(float distance) : _timer(0), _reference(), _wanderDistance(distance), _wanderSteps(0)
+RandomMovementGenerator<T>::RandomMovementGenerator(float distance/* = 0.0f*/, bool force2DPositionRelocation/* = false*/) : _timer(0), _reference(), _wanderDistance(distance), _wanderSteps(0), _force2DPositionRelocation(force2DPositionRelocation)
 {
     this->Mode = MOTION_MODE_DEFAULT;
     this->Priority = MOTION_PRIORITY_NORMAL;
     this->Flags = MOVEMENTGENERATOR_FLAG_INITIALIZATION_PENDING;
     this->BaseUnitState = UNIT_STATE_ROAMING;
 }
 
-template RandomMovementGenerator<Creature>::RandomMovementGenerator(float/* distance*/);
+template RandomMovementGenerator<Creature>::RandomMovementGenerator(float/* distance*/, bool/* force2DPositionRelocation*/);
 
 template<class T>
 MovementGeneratorType RandomMovementGenerator<T>::GetMovementGeneratorType() const
@@ -124,7 +124,10 @@ void RandomMovementGenerator<Creature>::SetRandomLocation(Creature* owner)
     Position position(_reference);
     float distance = frand(0.f, _wanderDistance);
     float angle = frand(0.f, float(M_PI * 2));
-    owner->MovePositionToFirstCollision(position, distance, angle);
+    if (_force2DPositionRelocation)
+        owner->GetNearPoint2D(nullptr, position.m_positionX, position.m_positionY, distance, frand(0.f, 2.f * float(M_PI)));
+    else
+        owner->MovePositionToFirstCollision(position, distance, angle);
 
     // Check if the destination is in LOS
     if (!owner->IsWithinLOS(position.GetPositionX(), position.GetPositionY(), position.GetPositionZ()))

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

@@ -28,7 +28,7 @@ template<class T>
 class RandomMovementGenerator : public MovementGeneratorMedium<T, RandomMovementGenerator<T>>
 {
     public:
-        explicit RandomMovementGenerator(float distance = 0.0f);
+        explicit RandomMovementGenerator(float distance = 0.0f, bool force2DPositionRelocation = false);
 
         MovementGeneratorType GetMovementGeneratorType() const override;
 
@@ -51,6 +51,7 @@ class RandomMovementGenerator : public MovementGeneratorMedium<T, RandomMovement
         Position _reference;
         float _wanderDistance;
         uint8 _wanderSteps;
+        bool _force2DPositionRelocation;
 };
 
 #endif