TBlkList

        void Setup( TLevel *MapLevel, float PrefetchRange );
        void Cleanup( void );

        // Return the square range to the given post location from the center of our data
        int  RangeFromCenter( int levelPostRow, int levelPostCol );

        // Incrementally move the viewer and swap blocks as needed
        void Update( float x, float y );

        // Return the maximum distance from the current postion in level
        // post space at which all data is owned by this list or will ever be
        // available
        int  GetAvailablePostRange( void )              { return availableRange; };
        int  GetMaxPostRange( void )                    { return interestRange; };

        // Return the min and max elevations within the current available range
        // (positive Z is DOWN)
        float   GetMaxZ(void)   { return maxZ; };
        float   GetMinZ(void)   { return minZ; };

        // Return a pointer to the requested post in our levels database.
        // The caller of this function must ensure that the post is within
        // the available range.  Also, the post pointer may become invalid
        // after a call to "Update"
        Tpost* GetPost( int levelPostRow, int levelPostCol );

  private:

        // Incrementally move the viewpoint (less than on LOD block in any direction)
        void UpdateBlockList( int vx, int vy );

        // Build the block list as required for a new position (including large moves)
        void RebuildBlockList( void );
 

        // Add a block to our active list
        void InsertBlock( int row, int col );

        // Release the most distant blocks in the list to make room for new ones
        void ReleaseDistantBlocks( void );

        // Compute the maximum distance from the current postion in global
        // post space at which all data is owned by this list
        void ComputeAvailableRange( void );

  private:
        // Pointer to the map level we're operating with
        TLevel *myLevelPtr;

        // The level post location of the center of attention of this list
        int             ourLevelPostRow;
        int             ourLevelPostCol;

        // The block row and column of the center of attention of this list
        int             ourBlockRow;
        int             ourBlockCol;

        // Max and min z values within all loaded blocks in the list
        // (positive Z is DOWN)
        float   maxZ;
        float   minZ;

        // linked list of all the blocks we own
        TListEntry     *head;
        TListEntry      *tail;

        // Level post space distance to which we are interested in data from this list
        int             interestRange;
        int             availableRange;

        // Block space distance at which to bring blocks in and out
        int             inBlockDistance;
        int             outBlockDistance;
 

#ifdef USE_SH_POOLS
  public:
        // Overload new/delete to use a SmartHeap fixed size pool
        void *operator new(size_t size) { ShiAssert( size == sizeof(TBlockList) ); return MemAllocFS(pool);     };
        void operator delete(void *mem) { if (mem) MemFreeFS(mem); };
        static void InitializeStorage() { pool = MemPoolInitFS( sizeof(TBlockList), 4, 0 ); };
        static void ReleaseStorage()    { MemPoolFree( pool ); };
        static MEM_POOL pool;
#endif

TListEntry

#ifdef USE_SH_POOLS
  public:
        // Overload new/delete to use a SmartHeap fixed size pool
        void *operator new(size_t size) { ShiAssert( size == sizeof(TListEntry) ); return MemAllocFS(pool);     };
        void operator delete(void *mem) { if (mem) MemFreeFS(mem); };
        static void InitializeStorage() { pool = MemPoolInitFS( sizeof(TListEntry), 4, 0 ); };
        static void ReleaseStorage()    { MemPoolFree( pool ); };
        static MEM_POOL pool;
#endif
};