Core/Movement: first part of porting the new creature hover handling

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

@@ -631,12 +631,8 @@ bool Unit::IsWithinMeleeRangeAt(Position const& pos, Unit const* obj) const
 
     float dx = pos.GetPositionX() - obj->GetPositionX();
     float dy = pos.GetPositionY() - obj->GetPositionY();
+    float dz = GetPositionZ() - obj->GetPositionZ();
 
-    float z = pos.GetPositionZ();
-    if (HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-        z -= GetFloatValue(UNIT_FIELD_HOVERHEIGHT);
-
-    float dz = z - obj->GetPositionZMinusOffset();
     float distsq = dx*dx + dy*dy + dz*dz;
 
     float maxdist = GetMeleeRange(obj);
@@ -660,20 +656,7 @@ bool Unit::IsWithinBoundaryRadius(const Unit* obj) const
     return IsInDist(obj, objBoundaryRadius);
 }
 
-void Unit::GetRandomContactPoint(Unit const* obj, float &x, float &y, float &z, float distance2dMin, float distance2dMax) const
-{
-    float combat_reach = GetCombatReach();
-    if (combat_reach < 0.1f) // sometimes bugged for players
-        combat_reach = DEFAULT_COMBAT_REACH;
-
-    uint32 attacker_number = getAttackers().size();
-    if (attacker_number > 0)
-        --attacker_number;
-    GetNearPoint(obj, x, y, z, obj->GetCombatReach(), distance2dMin+(distance2dMax-distance2dMin) * (float)rand_norm()
-        , GetAngle(obj) + (attacker_number ? (static_cast<float>(M_PI/2) - static_cast<float>(M_PI) * (float)rand_norm()) * float(attacker_number) / combat_reach * 0.3f : 0));
-}
-
-AuraApplication * Unit::GetVisibleAura(uint8 slot) const
+AuraApplication* Unit::GetVisibleAura(uint8 slot) const
 {
     VisibleAuraMap::const_iterator itr = m_visibleAuras.find(slot);
     if (itr != m_visibleAuras.end())
@@ -11897,15 +11880,6 @@ void Unit::Kill(Unit* victim, bool durabilityLoss)
     }
 }
 
-float Unit::GetPositionZMinusOffset() const
-{
-    float offset = 0.0f;
-    if (HasUnitMovementFlag(MOVEMENTFLAG_HOVER))
-        offset = GetFloatValue(UNIT_FIELD_HOVERHEIGHT);
-
-    return GetPositionZ() - offset;
-}
-
 void Unit::SetControlled(bool apply, UnitState state)
 {
     if (apply)
@@ -13562,6 +13536,20 @@ bool Unit::IsFalling() const
     return m_movementInfo.HasMovementFlag(MOVEMENTFLAG_FALLING | MOVEMENTFLAG_FALLING_FAR) || movespline->isFalling();
 }
 
+bool Unit::CanSwim() const
+{
+    // Mirror client behavior, if this method returns false then client will not use swimming animation and for players will apply gravity as if there was no water
+    if (HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_CANNOT_SWIM))
+        return false;
+    if (HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_PVP_ATTACKABLE)) // is player
+        return true;
+    if (HasFlag(UNIT_FIELD_FLAGS_2, 0x1000000))
+        return false;
+    if (IsPet() && HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_PET_IN_COMBAT))
+        return true;
+    return HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_RENAME | UNIT_FLAG_UNK_15);
+}
+
 void Unit::NearTeleportTo(Position const& pos, bool casting /*= false*/)
 {
     DisableSpline();
@@ -13803,7 +13791,7 @@ void Unit::SendTeleportPacket(Position const& pos)
     // MSG_MOVE_TELEPORT is sent to self in order to trigger MSG_MOVE_TELEPORT_ACK and update the position server side
 
     // This oldPos actually contains the destination position if the Unit is a Player.
-    Position oldPos = {GetPositionX(), GetPositionY(), GetPositionZMinusOffset(), GetOrientation()};
+    Position oldPos = {GetPositionX(), GetPositionY(), GetPositionZ(), GetOrientation()};
 
     if (GetTypeId() == TYPEID_UNIT)
         Relocate(&pos); // Relocate the unit to its new position in order to build the packets correctly.
@@ -13861,7 +13849,7 @@ void Unit::SendTeleportPacket(Position const& pos)
         data2.WriteByteSeq(guid[4]);
         data2 << float(GetOrientation());
         data2.WriteByteSeq(guid[7]);
-        data2 << float(GetPositionZMinusOffset());
+        data2 << float(GetPositionZ());
         data2.WriteByteSeq(guid[0]);
         data2.WriteByteSeq(guid[6]);
         data2 << float(GetPositionY());
@@ -14215,7 +14203,7 @@ 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);
@@ -14230,7 +14218,7 @@ 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();
 }
@@ -14409,7 +14397,8 @@ bool Unit::SetHover(bool enable, bool packetOnly /*= false*/)
         else
         {
             RemoveUnitMovementFlag(MOVEMENTFLAG_HOVER);
-            if (hoverHeight)
+            //! Dying creatures will MoveFall from setDeathState
+            if (hoverHeight && (!isDying() || GetTypeId() != TYPEID_UNIT))
             {
                 float newZ = GetPositionZ() - hoverHeight;
                 UpdateAllowedPositionZ(GetPositionX(), GetPositionY(), newZ);