fCraft.Session.UpdateVisibleEntities C# (CSharp) Method

        void UpdateVisibleEntities() {
            if( SpectatedPlayer != null ) {
                if( SpectatedPlayer.IsDisconnected || !Player.CanSee( SpectatedPlayer ) ) {
                    Player.Message( "Stopped spectating {0}&S (disconnected)", SpectatedPlayer.GetClassyName() );
                    SpectatedPlayer = null;
                } else {
                    Position spectatePos = SpectatedPlayer.Position;
                    World spectateWorld = SpectatedPlayer.World;
                    if( spectateWorld != Player.World ) {
                        postJoinPosition = spectatePos;
                        Player.Message( "Joined {0}&S to continue spectating {1}",
                                        spectateWorld.GetClassyName(),
                                        SpectatedPlayer.GetClassyName() );
                        JoinWorldNow( spectateWorld, false, false );
                    } else if( spectatePos != Player.Position ) {
                        SendNow( PacketWriter.MakeSelfTeleport( spectatePos ) );
                    }
                }
            }

            Player[] worldPlayerList = Player.World.PlayerList;
            Position pos = Player.Position;

            for( int i = 0; i < worldPlayerList.Length; i++ ) {
                Player otherPlayer = worldPlayerList[i];
                if( otherPlayer == Player ) continue;
                if( !Player.CanSee( otherPlayer ) ) continue;
                if( SpectatedPlayer == otherPlayer || otherPlayer.Session.SpectatedPlayer == Player ) continue;

                Position otherPos = otherPlayer.Position;
                int distance = pos.DistanceSquaredTo( otherPos );

                VisibleEntity entity;
                // if Player has a corresponding VisibleEntity
                if( entities.TryGetValue( otherPlayer, out entity ) ) {
                    entity.MarkedForRetention = true;

                    if( entity.LastKnownRank != otherPlayer.Info.Rank ) {
                        ReAddEntity( entity, otherPlayer, otherPos );
                        entity.LastKnownRank = otherPlayer.Info.Rank;

                    } else if( entity.Hidden ) {
                        if( distance < entityShowingThreshold ) {
                            ShowEntity( entity, otherPos );
                        }

                    } else {
                        if( distance > entityHidingThreshold ) {
                            HideEntity( entity );

                        } else if( entity.LastKnownPosition != otherPos ) {
                            MoveEntity( entity, otherPos );
                        }
                    }
                } else {
                    AddEntity( otherPlayer, otherPos );
                }
            }
            

            // Find entities to remove (not marked for retention).
            foreach( var pair in entities ) {
                if( pair.Value.MarkedForRetention ) {
                    pair.Value.MarkedForRetention = false;
                } else {
                    playersToRemove.Push( pair.Key );
                }
            }

            // Remove non-retained entities
            while( playersToRemove.Count > 0 ) {
                RemoveEntity( playersToRemove.Pop() );
            }

            fullUpdateCounter++;
            if( fullUpdateCounter >= FullPositionUpdateInterval ) {
                fullUpdateCounter = 0;
            }
        }