Revert "Core/Entities: implement IsInAir"

This reverts commit 4c27329bed.

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

@@ -2651,7 +2651,10 @@ void Creature::UpdateMovementFlags()
         return;
 
     // Set the movement flags if the creature is in that mode. (Only fly if actually in air, only swim if in water, etc)
-    bool isInAir = IsInAir(*this, GetFloorZ() + GROUND_HEIGHT_TOLERANCE) || IsInAir(*this, GetFloorZ() - GROUND_HEIGHT_TOLERANCE);
+    float ground = GetFloorZ();
+
+    bool canHover = CanHover();
+    bool isInAir = (G3D::fuzzyGt(GetPositionZ(), ground + (canHover ? GetFloatValue(UNIT_FIELD_HOVERHEIGHT) : 0.0f) + GROUND_HEIGHT_TOLERANCE) || G3D::fuzzyLt(GetPositionZ(), ground - GROUND_HEIGHT_TOLERANCE)); // Can be underground too, prevent the falling
 
     if (GetMovementTemplate().IsFlightAllowed() && isInAir && !IsFalling())
     {

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

@@ -3164,11 +3164,6 @@ bool Unit::IsUnderWater() const
     return GetLiquidStatus() & LIQUID_MAP_UNDER_WATER;
 }
 
-bool Unit::IsInAir(Position const destination, float destinationFloor, bool honorHover/* = true*/) const
-{
-    return std::fabs(destination.GetPositionZ() - (honorHover ? GetHoverOffset() : 0.f) - destinationFloor) > 0.1f;
-}
-
 void Unit::ProcessPositionDataChanged(PositionFullTerrainStatus const& data)
 {
     ZLiquidStatus oldLiquidStatus = GetLiquidStatus();

src/server/game/Entities/Unit/Unit.h

@@ -1171,7 +1171,6 @@ class TC_GAME_API Unit : public WorldObject
 
         bool IsInWater() const;
         bool IsUnderWater() const;
-        bool IsInAir(Position const destination, float destinationFloor, bool honorHover = true) const;
         bool isInAccessiblePlaceFor(Creature const* c) const;
 
         void SendHealSpellLog(HealInfo& healInfo, bool critical = false);