Core/Movement: Fixed creature hover

Closes #15177

(cherry picked from commit 2baa81065ba27f0a6d278a8dd8a79b7c831e0a2b)

10 files changed, 59 insertions, 93 deletions

diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index 40e26027ba0..329ec612800 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -446,6 +446,7 @@ void Creature::RemoveCorpse(bool setSpawnTime, bool destroyForNearbyPlayers)
                 transport->CalculatePassengerPosition(x, y, z, &o);
         }
 
+        UpdateAllowedPositionZ(x, y, z);
         SetHomePosition(x, y, z, o);
         GetMap()->CreatureRelocation(this, x, y, z, o);
     }
@@ -1151,11 +1152,7 @@ bool Creature::Create(ObjectGuid::LowType guidlow, Map* map, uint32 entry, Posit
     LoadCreaturesAddon();
 
     //! Need to be called after LoadCreaturesAddon - MOVEMENTFLAG_HOVER is set there
-    if (HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-    {
-        //! Relocate again with updated Z coord
-        m_positionZ += m_unitData->HoverHeight;
-    }
+    m_positionZ += GetHoverOffset();
 
     LastUsedScriptID = GetScriptId();
 
@@ -1769,7 +1766,7 @@ bool Creature::LoadFromDB(ObjectGuid::LowType spawnId, Map* map, bool addToMap,
         return false;
 
     //We should set first home position, because then AI calls home movement
-    SetHomePosition(data->spawnPoint);
+    SetHomePosition(*this);
 
     m_deathState = ALIVE;
 
@@ -3112,7 +3109,7 @@ void Creature::UpdateMovementFlags()
     // Set the movement flags if the creature is in that mode. (Only fly if actually in air, only swim if in water, etc)
     float ground = GetFloorZ();
 
-    bool isInAir = (G3D::fuzzyGt(GetPositionZMinusOffset(), ground + GROUND_HEIGHT_TOLERANCE) || G3D::fuzzyLt(GetPositionZMinusOffset(), ground - GROUND_HEIGHT_TOLERANCE)); // Can be underground too, prevent the falling
+    bool isInAir = (G3D::fuzzyGt(GetPositionZ(), ground + GROUND_HEIGHT_TOLERANCE) || G3D::fuzzyLt(GetPositionZ(), ground - GROUND_HEIGHT_TOLERANCE)); // Can be underground too, prevent the falling
 
     if (GetCreatureTemplate()->InhabitType & INHABIT_AIR && isInAir && !IsFalling())
     {
diff --git a/src/server/game/Entities/Object/Object.cpp b/src/server/game/Entities/Object/Object.cpp
index e4e13390c78..985d079826c 100644
--- a/src/server/game/Entities/Object/Object.cpp
+++ b/src/server/game/Entities/Object/Object.cpp
@@ -1303,7 +1303,9 @@ Position WorldObject::GetRandomPoint(Position const& srcPos, float distance) con
 
 void WorldObject::UpdateGroundPositionZ(float x, float y, float &z) const
 {
-    z = GetMapHeight(x, y, z);
+    float new_z = GetMapHeight(x, y, z);
+    if (new_z > INVALID_HEIGHT)
+        z = new_z + (isType(TYPEMASK_UNIT) ? static_cast<Unit const*>(this)->GetHoverOffset() : 0.0f);
 }
 
 void WorldObject::UpdateAllowedPositionZ(float x, float y, float &z) const
@@ -1312,66 +1314,44 @@ void WorldObject::UpdateAllowedPositionZ(float x, float y, float &z) const
     if (GetTransport())
         return;
 
-    switch (GetTypeId())
+    if (Unit const* unit = ToUnit())
     {
-        case TYPEID_UNIT:
-        {
-            // non fly unit don't must be in air
-            // non swim unit must be at ground (mostly speedup, because it don't must be in water and water level check less fast
-            if (!ToCreature()->CanFly())
-            {
-                bool canSwim = ToCreature()->CanSwim();
-                float ground_z = z;
-                float max_z = canSwim
-                    ? GetMapWaterOrGroundLevel(x, y, z, &ground_z)
-                    : (ground_z = GetMapHeight(x, y, z));
-                if (max_z > INVALID_HEIGHT)
-                {
-                    if (z > max_z)
-                        z = max_z;
-                    else if (z < ground_z)
-                        z = ground_z;
-                }
-            }
-            else
-            {
-                float ground_z = GetMapHeight(x, y, z);
-                if (std::fabs(z - ground_z) < GetCollisionHeight())
-                    z = ground_z;
-            }
-            break;
-        }
-        case TYPEID_PLAYER:
+        if (!unit->CanFly())
         {
-            // for server controlled moves playr work same as creature (but it can always swim)
-            if (!ToPlayer()->CanFly())
-            {
-                float ground_z = z;
-                float max_z = GetMapWaterOrGroundLevel(x, y, z, &ground_z);
-                if (max_z > INVALID_HEIGHT)
-                {
-                    if (z > max_z)
-                        z = max_z;
-                    else if (z < ground_z)
-                        z = ground_z;
-                }
-            }
+            bool canSwim = unit->CanSwim();
+            float ground_z = z;
+            float max_z;
+            if (canSwim)
+                max_z = GetMapWaterOrGroundLevel(x, y, z, &ground_z);
             else
+                max_z = ground_z = GetMapHeight(x, y, z);
+
+            if (max_z > INVALID_HEIGHT)
             {
-                float ground_z = GetMapHeight(x, y, z);
-                if (std::fabs(z - ground_z) < GetCollisionHeight())
+                // hovering units cannot go below their hover height
+                float hoverOffset = unit->GetHoverOffset();
+                max_z += hoverOffset;
+                ground_z += hoverOffset;
+
+                if (z > max_z)
+                    z = max_z;
+                else if (z < ground_z)
                     z = ground_z;
             }
-            break;
         }
-        default:
+        else
         {
-            float ground_z = GetMapHeight(x, y, z);
-            if (ground_z > INVALID_HEIGHT)
+            float ground_z = GetMapHeight(x, y, z) + unit->GetHoverOffset();
+            if (z < ground_z)
                 z = ground_z;
-            break;
         }
     }
+    else
+    {
+        float ground_z = GetMapHeight(x, y, z);
+        if (ground_z > INVALID_HEIGHT)
+            z = ground_z;
+    }
 }
 
 float WorldObject::GetGridActivationRange() const
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 2115fc96aa3..20a398649bd 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -566,7 +566,7 @@ bool Unit::IsWithinMeleeRange(Unit const* obj) const
 
     float dx = GetPositionX() - obj->GetPositionX();
     float dy = GetPositionY() - obj->GetPositionY();
-    float dz = GetPositionZMinusOffset() - obj->GetPositionZMinusOffset();
+    float dz = GetPositionZ() - obj->GetPositionZ();
     float distsq = dx*dx + dy*dy + dz*dz;
 
     float maxdist = GetMeleeRange(obj) + GetTotalAuraModifier(SPELL_AURA_MOD_AUTOATTACK_RANGE);
@@ -11574,15 +11574,6 @@ void Unit::SetMeleeAnimKitId(uint16 animKitId)
     }
 }
 
-float Unit::GetPositionZMinusOffset() const
-{
-    float offset = 0.0f;
-    if (HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-        offset = m_unitData->HoverHeight;
-
-    return GetPositionZ() - offset;
-}
-
 void Unit::SetControlled(bool apply, UnitState state)
 {
     if (apply)
@@ -13294,7 +13285,7 @@ void Unit::SetFacingTo(float ori, bool force)
         return;
 
     Movement::MoveSplineInit init(this);
-    init.MoveTo(GetPositionX(), GetPositionY(), GetPositionZMinusOffset(), false);
+    init.MoveTo(GetPositionX(), GetPositionY(), GetPositionZ(), false);
     if (GetTransport())
         init.DisableTransportPathTransformations(); // It makes no sense to target global orientation
     init.SetFacing(ori);
@@ -13309,7 +13300,7 @@ void Unit::SetFacingToObject(WorldObject const* object, bool force)
 
     /// @todo figure out under what conditions creature will move towards object instead of facing it where it currently is.
     Movement::MoveSplineInit init(this);
-    init.MoveTo(GetPositionX(), GetPositionY(), GetPositionZMinusOffset(), false);
+    init.MoveTo(GetPositionX(), GetPositionY(), GetPositionZ(), false);
     init.SetFacing(GetAngle(object));   // when on transport, GetAngle will still return global coordinates (and angle) that needs transforming
     init.Launch();
 }
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 75d7e60897e..da63f0558c7 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -1768,8 +1768,6 @@ class TC_GAME_API Unit : public WorldObject
         void SetExtraUnitMovementFlags(uint32 f) { m_movementInfo.SetExtraMovementFlags(f); }
         bool IsSplineEnabled() const;
 
-        float GetPositionZMinusOffset() const;
-
         void SetControlled(bool apply, UnitState state);
         void ApplyControlStatesIfNeeded();
 
@@ -1828,6 +1826,11 @@ class TC_GAME_API Unit : public WorldObject
         bool IsFalling() const;
         virtual bool CanSwim() const;
 
+        float GetHoverOffset() const
+        {
+            return HasUnitMovementFlag(MOVEMENTFLAG_HOVER) ? *m_unitData->HoverHeight : 0.0f;
+        }
+
         void RewardRage(uint32 baseRage);
 
         virtual float GetFollowAngle() const { return static_cast<float>(M_PI/2); }
diff --git a/src/server/game/Handlers/MovementHandler.cpp b/src/server/game/Handlers/MovementHandler.cpp
index 9fe6808defb..ac873eb6d01 100644
--- a/src/server/game/Handlers/MovementHandler.cpp
+++ b/src/server/game/Handlers/MovementHandler.cpp
@@ -90,10 +90,7 @@ void WorldSession::HandleMoveWorldportAck()
         return;
     }
 
-    float z = loc.GetPositionZ();
-    if (GetPlayer()->HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-        z += GetPlayer()->m_unitData->HoverHeight;
-
+    float z = loc.GetPositionZ() + GetPlayer()->GetHoverOffset();
     GetPlayer()->Relocate(loc.GetPositionX(), loc.GetPositionY(), z, loc.GetOrientation());
     GetPlayer()->SetFallInformation(0, GetPlayer()->GetPositionZ());
 
diff --git a/src/server/game/Maps/Map.cpp b/src/server/game/Maps/Map.cpp
index 10a1eb2e6ce..fc2c950b57c 100644
--- a/src/server/game/Maps/Map.cpp
+++ b/src/server/game/Maps/Map.cpp
@@ -1138,12 +1138,6 @@ void Map::PlayerRelocation(Player* player, float x, float y, float z, float orie
     Cell old_cell(player->GetPositionX(), player->GetPositionY());
     Cell new_cell(x, y);
 
-    //! If hovering, always increase our server-side Z position
-    //! Client automatically projects correct position based on Z coord sent in monster move
-    //! and HoverHeight sent in object updates
-    if (player->HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-        z += player->m_unitData->HoverHeight;
-
     player->Relocate(x, y, z, orientation);
     if (player->IsVehicle())
         player->GetVehicleKit()->RelocatePassengers();
@@ -1173,12 +1167,6 @@ void Map::CreatureRelocation(Creature* creature, float x, float y, float z, floa
     if (!respawnRelocationOnFail && !getNGrid(new_cell.GridX(), new_cell.GridY()))
         return;
 
-    //! If hovering, always increase our server-side Z position
-    //! Client automatically projects correct position based on Z coord sent in monster move
-    //! and HoverHeight sent in object updates
-    if (creature->HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-        z += creature->m_unitData->HoverHeight;
-
     Cell old_cell = creature->GetCurrentCell();
     // delay creature move for grid/cell to grid/cell moves
     if (old_cell.DiffCell(new_cell) || old_cell.DiffGrid(new_cell))
diff --git a/src/server/game/Movement/MotionMaster.cpp b/src/server/game/Movement/MotionMaster.cpp
index 7df25b72817..d7be55b03e7 100644
--- a/src/server/game/Movement/MotionMaster.cpp
+++ b/src/server/game/Movement/MotionMaster.cpp
@@ -346,7 +346,7 @@ void MotionMaster::MoveCloserAndStop(uint32 id, Unit* target, float distance)
     {
         // we are already close enough. We just need to turn toward the target without changing position.
         Movement::MoveSplineInit init(_owner);
-        init.MoveTo(_owner->GetPositionX(), _owner->GetPositionY(), _owner->GetPositionZMinusOffset());
+        init.MoveTo(_owner->GetPositionX(), _owner->GetPositionY(), _owner->GetPositionZ());
         init.SetFacing(target);
         init.Launch();
         Mutate(new EffectMovementGenerator(id), MOTION_SLOT_ACTIVE);
@@ -510,7 +510,7 @@ void MotionMaster::MoveCirclePath(float x, float y, float z, float radius, bool
         if (_owner->IsFlying())
             point.z = z;
         else
-            point.z = _owner->GetMapHeight(point.x, point.y, z);
+            point.z = _owner->GetMapHeight(point.x, point.y, z) + _owner->GetHoverOffset();
 
         init.Path().push_back(point);
     }
@@ -615,7 +615,7 @@ void MotionMaster::MoveFall(uint32 id /*=0*/)
     }
 
     Movement::MoveSplineInit init(_owner);
-    init.MoveTo(_owner->GetPositionX(), _owner->GetPositionY(), tz, false);
+    init.MoveTo(_owner->GetPositionX(), _owner->GetPositionY(), tz + _owner->GetHoverOffset(), false);
     init.SetFall();
     init.Launch();
     Mutate(new EffectMovementGenerator(id), MOTION_SLOT_CONTROLLED);
diff --git a/src/server/game/Movement/MovementGenerators/HomeMovementGenerator.cpp b/src/server/game/Movement/MovementGenerators/HomeMovementGenerator.cpp
index 191877289c8..df1adb19684 100644
--- a/src/server/game/Movement/MovementGenerators/HomeMovementGenerator.cpp
+++ b/src/server/game/Movement/MovementGenerators/HomeMovementGenerator.cpp
@@ -51,6 +51,7 @@ void HomeMovementGenerator<Creature>::SetTargetLocation(Creature* owner)
         owner->GetHomePosition(x, y, z, o);
         init.SetFacing(o);
     }
+    owner->UpdateAllowedPositionZ(x, y, z);
     init.MoveTo(x, y, z);
     init.SetWalk(false);
     init.Launch();
diff --git a/src/server/game/Movement/MovementGenerators/TargetedMovementGenerator.cpp b/src/server/game/Movement/MovementGenerators/TargetedMovementGenerator.cpp
index 0465c958990..102a4728fc9 100755
--- a/src/server/game/Movement/MovementGenerators/TargetedMovementGenerator.cpp
+++ b/src/server/game/Movement/MovementGenerators/TargetedMovementGenerator.cpp
@@ -124,29 +124,38 @@ void TargetedMovementGenerator<T, D>::SetTargetLocation(T* owner, bool updateDes
     float x, y, z;
     if (updateDestination || !_path)
     {
+        float size = owner->GetCombatReach();
+        float hoverDiff = owner->GetHoverOffset() - GetTarget()->GetHoverOffset();
         if (!_offset)
         {
             if (GetTarget()->IsWithinDistInMap(owner, CONTACT_DISTANCE))
                 return;
 
-            GetTarget()->GetContactPoint(owner, x, y, z);
+            if (hoverDiff)
+                size = size > hoverDiff ? std::sqrt(size * size - hoverDiff * hoverDiff) : 0.0f;
+
+            GetTarget()->GetNearPoint(owner, x, y, z, size, CONTACT_DISTANCE, GetTarget()->GetAngle(owner));
         }
         else
         {
             float distance = _offset + 1.0f;
-            float size = owner->GetCombatReach();
 
             if (owner->IsPet() && GetTarget()->GetTypeId() == TYPEID_PLAYER)
             {
                 distance = 1.0f;
                 size = 1.0f;
             }
+            else if (hoverDiff)
+                size = size > hoverDiff ? std::sqrt(size * size - hoverDiff * hoverDiff) : 0.0f;
 
             if (GetTarget()->IsWithinDistInMap(owner, distance))
                 return;
 
             GetTarget()->GetClosePoint(x, y, z, size, _offset, _angle);
         }
+
+        if (owner->IsHovering())
+            owner->UpdateAllowedPositionZ(x, y, z);
     }
     else
     {
diff --git a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_mimiron.cpp b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_mimiron.cpp
index 250e2f64cac..062b5c4a003 100644
--- a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_mimiron.cpp
+++ b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_mimiron.cpp
@@ -613,7 +613,7 @@ class boss_mimiron : public CreatureScript
                             {
                                 if (Creature* aerial = ObjectAccessor::GetCreature(*me, instance->GetGuidData(DATA_AERIAL_COMMAND_UNIT)))
                                 {
-                                    aerial->GetMotionMaster()->MoveLand(0, (aerial->GetPositionX(), aerial->GetPositionY(), aerial->GetPositionZMinusOffset()));
+                                    aerial->GetMotionMaster()->MoveLand(0, (aerial->GetPositionX(), aerial->GetPositionY(), aerial->GetPositionZ()));
                                     aerial->SetAnimTier(UNIT_BYTE1_FLAG_NONE, false);
                                     aerial->CastSpell(vx001, SPELL_MOUNT_VX_001);
                                     aerial->CastSpell(aerial, SPELL_HALF_HEAL);