fix(Core): creature movement bugs (#4544)

- fix UpdateEnvironmentIfNeeded was changing flying creature status all the time. closes: #4447
- fix hovering state was causing bugs at #4466
- add animation state priority: fly > hover > ground

Co-authored-by: Wotex <fm@gmail.com>
Co-authored-by: Francesco Borzì <borzifrancesco@gmail.com>
Co-authored-by: Patrick Lewis <pat@lo5t.com>

data/sql/updates/pending_db_world/rev_1613069340138846000.sql

@@ -0,0 +1,3 @@
+INSERT INTO `version_db_world` (`sql_rev`) VALUES ('1613069340138846000');
+
+UPDATE `creature_template` SET `InhabitType`=1 WHERE `entry`=36725;

src/server/game/Entities/Creature/Creature.cpp

@@ -2758,6 +2758,8 @@ bool Creature::SetDisableGravity(bool disable, bool packetOnly/*=false*/)
     if (!packetOnly && !Unit::SetDisableGravity(disable))
         return false;
 
+    applyInhabitFlags();
+
     if (!movespline->Initialized())
         return true;
 
@@ -2767,6 +2769,26 @@ bool Creature::SetDisableGravity(bool disable, bool packetOnly/*=false*/)
     return true;
 }
 
+void Creature::applyInhabitFlags()
+{
+    if (IsAlive() && !HasUnitState(UNIT_STATE_ROOT) && !HasUnitMovementFlag(MOVEMENTFLAG_ROOT))
+    {
+        if (IsLevitating())
+        {
+            SetByteValue(UNIT_FIELD_BYTES_1, UNIT_BYTES_1_OFFSET_ANIM_TIER, UNIT_BYTE1_FLAG_FLY);
+            return;
+        }
+
+        if (IsHovering())
+        {
+            SetByteValue(UNIT_FIELD_BYTES_1, UNIT_BYTES_1_OFFSET_ANIM_TIER, UNIT_BYTE1_FLAG_HOVER);
+            return;
+        }
+
+        SetByteValue(UNIT_FIELD_BYTES_1, UNIT_BYTES_1_OFFSET_ANIM_TIER, UNIT_BYTE1_FLAG_GROUND);
+    }
+}
+
 bool Creature::SetSwim(bool enable)
 {
     if (!Unit::SetSwim(enable))
@@ -2873,11 +2895,7 @@ bool Creature::SetHover(bool enable, bool packetOnly /*= false*/)
     if (!packetOnly && !Unit::SetHover(enable))
         return false;
 
-    //! Unconfirmed for players:
+   applyInhabitFlags();
-    if (enable)
-        SetByteFlag(UNIT_FIELD_BYTES_1, UNIT_BYTES_1_OFFSET_ANIM_TIER, UNIT_BYTE1_FLAG_HOVER);
-    else
-        RemoveByteFlag(UNIT_FIELD_BYTES_1, UNIT_BYTES_1_OFFSET_ANIM_TIER, UNIT_BYTE1_FLAG_HOVER);
 
     if (!movespline->Initialized())
         return true;

src/server/game/Entities/Creature/Creature.h

@@ -832,6 +832,8 @@ private:
     Spell const* _focusSpell;   ///> Locks the target during spell cast for proper facing
 
     bool _isMissingSwimmingFlagOutOfCombat;
+
+    void applyInhabitFlags();
 };
 
 class AssistDelayEvent : public BasicEvent

src/server/game/Entities/Unit/Unit.cpp

@@ -3816,28 +3816,39 @@ void Unit::UpdateEnvironmentIfNeeded(const uint8 option)
                 changed = true;
             }
         }
-        else if (c->CanFly() && isInAir)
+        else if (c->CanFly() && isInAir && !c->IsFalling())
         {
-            if (!c->IsFalling() && (!HasUnitMovementFlag(MOVEMENTFLAG_CAN_FLY) || !HasUnitMovementFlag(MOVEMENTFLAG_DISABLE_GRAVITY) || !HasUnitMovementFlag(MOVEMENTFLAG_HOVER)))
+
+            if (!HasUnitMovementFlag(MOVEMENTFLAG_CAN_FLY) || !HasUnitMovementFlag(MOVEMENTFLAG_DISABLE_GRAVITY))
             {
                 SetCanFly(true);
                 SetDisableGravity(true);
-                if (IsAlive() && (c->CanHover() || HasAuraType(SPELL_AURA_HOVER)))
-                    SetHover(true);
                 changed = true;
             }
-        }
+
-        else
+            if (IsHovering() && !HasAuraType(SPELL_AURA_HOVER))
             {
-            if (HasUnitMovementFlag(MOVEMENTFLAG_CAN_FLY) || HasUnitMovementFlag(MOVEMENTFLAG_FLYING) || HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-            {
-                SetCanFly(false);
-                RemoveUnitMovementFlag(MOVEMENTFLAG_FLYING);
-                if (!HasAuraType(SPELL_AURA_HOVER))
                 SetHover(false);
                 changed = true;
             }
-            if (HasUnitMovementFlag(MOVEMENTFLAG_DISABLE_GRAVITY) && !HasUnitMovementFlag(MOVEMENTFLAG_SWIMMING) && !HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
+
+        }
+        else
+        {
+            if (HasUnitMovementFlag(MOVEMENTFLAG_CAN_FLY) || HasUnitMovementFlag(MOVEMENTFLAG_FLYING))
+            {
+                SetCanFly(false);
+                RemoveUnitMovementFlag(MOVEMENTFLAG_FLYING);
+                changed = true;
+            }
+
+            if (!IsHovering() && IsAlive() && (c->CanHover() || HasAuraType(SPELL_AURA_HOVER)))
+            {
+                SetHover(true);
+                changed = true;
+            }
+
+            if (HasUnitMovementFlag(MOVEMENTFLAG_DISABLE_GRAVITY) && !HasUnitMovementFlag(MOVEMENTFLAG_SWIMMING))
             {
                 SetDisableGravity(false);
                 changed = true;

src/server/scripts/Northrend/IcecrownCitadel/boss_sindragosa.cpp

@@ -282,7 +282,6 @@ public:
             if (!_summoned)
             {
                 me->SetDisableGravity(true);
-                me->SetHover(true);
                 me->SetCanFly(true);
             }
         }
@@ -355,7 +354,6 @@ public:
             if (_summoned)
             {
                 me->SetDisableGravity(false);
-                me->SetHover(false);
                 me->SetCanFly(false);
             }
         }
@@ -452,8 +450,8 @@ public:
                     break;
                 case POINT_LAND_GROUND:
                     {
+                        _isInAirPhase = false;
                         me->SetDisableGravity(false);
-                        me->SetHover(false);
                         me->SetCanFly(false);
                         me->SetSpeed(MOVE_RUN, me->GetCreatureTemplate()->speed_run);
                         me->SetReactState(REACT_AGGRESSIVE);
@@ -594,6 +592,7 @@ public:
                         me->SetControlled(false, UNIT_STATE_ROOT);
                     }
 
+                    _isInAirPhase = true;
                     _didFirstFlyPhase = true;
                     Talk(SAY_AIR_PHASE);
                     me->SetReactState(REACT_PASSIVE);
@@ -659,7 +658,7 @@ public:
                     me->GetMotionMaster()->MoveLand(POINT_LAND_GROUND, SindragosaLandPos, 10.0f);
                     break;
                 case EVENT_THIRD_PHASE_CHECK:
-                    if (!me->HasByteFlag(UNIT_FIELD_BYTES_1, UNIT_BYTES_1_OFFSET_ANIM_TIER, UNIT_BYTE1_FLAG_HOVER))
+                    if (!_isInAirPhase)
                     {
                         Talk(SAY_PHASE_2);
                         events.ScheduleEvent(EVENT_ICE_TOMB, urand(7000, 10000));
@@ -697,6 +696,7 @@ public:
         bool _didFirstFlyPhase;
         bool _isBelow20Pct;
         bool _isThirdPhase;
+        bool _isInAirPhase;
     };
 
     CreatureAI* GetAI(Creature* creature) const override

src/server/scripts/Northrend/IcecrownCitadel/icecrown_citadel.cpp

@@ -3316,8 +3316,6 @@ public:
         npc_icc_nerubar_broodkeeperAI(Creature* creature) : ScriptedAI(creature)
         {
             me->SetDisableGravity(true);
-            me->SetCanFly(true);
-            me->SetHover(true);
             _didWebBeam = false;
             me->m_SightDistance = 100.0f; // for MoveInLineOfSight distance
         }
@@ -3338,16 +3336,18 @@ public:
             if (!_didWebBeam && who->GetTypeId() == TYPEID_PLAYER && me->GetExactDist2d(who) < 70.0f)
             {
                 _didWebBeam = true;
-                float nx = me->GetPositionX() + cos(me->GetOrientation()) * 2.0f;
+                float nx = me->GetPositionX();
-                float ny = me->GetPositionY() + sin(me->GetOrientation()) * 2.0f;
+                float ny = me->GetPositionY();
-                float nz = me->GetMap()->GetHeight(nx, ny, 50.0f);
+                float nz = me->GetFloorZ();
                 me->SetHomePosition(nx, ny, nz, me->GetOrientation());
                 me->CastSpell(me, SPELL_WEB_BEAM, false);
                 me->GetMotionMaster()->MovePoint(1, nx, ny, nz, false);
                 return;
             }
-            if (me->HasUnitMovementFlag(MOVEMENTFLAG_CAN_FLY))
+
+            if (me->IsLevitating())
                 return;
+
             ScriptedAI::MoveInLineOfSight(who);
         }
 
@@ -3358,11 +3358,9 @@ public:
 
         void JustReachedHome() override
         {
-            if (me->IsHovering())
+            if (me->IsLevitating())
             {
                 me->SetDisableGravity(false);
-                me->SetCanFly(false);
-                me->SetHover(false);
                 me->NearTeleportTo(me->GetPositionX(), me->GetPositionY(), me->GetPositionZ(), me->GetOrientation());
             }
         }
@@ -3371,11 +3369,10 @@ public:
         {
             if (type == POINT_MOTION_TYPE && id == 1)
             {
-                if (me->IsHovering())
+                if (me->IsLevitating())
                 {
                     me->SetDisableGravity(false);
-                    me->SetCanFly(false);
+                    me->SetOrientation(0.0f);
-                    me->SetHover(false);
                     me->NearTeleportTo(me->GetPositionX(), me->GetPositionY(), me->GetPositionZ(), me->GetOrientation());
                 }
             }
@@ -3383,7 +3380,7 @@ public:
 
         bool CanAIAttack(const Unit*  /*target*/) const override
         {
-            return !me->HasUnitMovementFlag(MOVEMENTFLAG_CAN_FLY);
+            return !me->IsLevitating();
         }
 
         void UpdateAI(uint32 diff) override