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flightgear/src/Scenery/newcache.hxx
2006-02-21 01:16:04 +00:00

139 lines
3.9 KiB
C++

// newcache.hxx -- routines to handle scenery tile caching
//
// Written by Curtis Olson, started December 2000.
//
// Copyright (C) 2000 Curtis L. Olson - http://www.flightgear.org/~curt
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#ifndef _NEWCACHE_HXX
#define _NEWCACHE_HXX
#ifndef __cplusplus
# error This library requires C++
#endif
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <map>
#include <simgear/bucket/newbucket.hxx>
#include <simgear/math/point3d.hxx>
#include "tileentry.hxx"
SG_USING_STD(map);
// A class to store and manage a pile of tiles
class FGNewCache {
typedef map < long, FGTileEntry * > tile_map;
typedef tile_map::iterator tile_map_iterator;
typedef tile_map::const_iterator const_tile_map_iterator;
// cache storage space
tile_map tile_cache;
// maximum cache size
int max_cache_size;
// pointers to allow an external linear traversal of cache entries
tile_map_iterator current;
// Free a tile cache entry
void entry_free( long cache_index );
public:
// Constructor
FGNewCache();
// Destructor
~FGNewCache();
// Initialize the tile cache subsystem
void init( void );
// Check if the specified "bucket" exists in the cache
bool exists( const SGBucket& b ) const;
#if 0
// Ensure at least one entry is free in the cache
bool make_space();
#endif
// Return the index of the oldest tile in the cache, return -1 if
// nothing available to be removed.
long get_oldest_tile();
// Clear the inner ring flag for all tiles in the cache so that
// the external tile scheduler can flag the inner ring correctly.
void clear_inner_ring_flags();
// Clear a cache entry, note that the cache only holds pointers
// and this does not free the object which is pointed to.
void clear_entry( long cache_entry );
// Clear all completely loaded tiles (ignores partially loaded tiles)
void clear_cache();
// Return a pointer to the specified tile cache entry
inline FGTileEntry *get_tile( const long tile_index ) const {
const_tile_map_iterator it = tile_cache.find( tile_index );
if ( it != tile_cache.end() ) {
it->second->set_timestamp(globals->get_sim_time_sec());
return it->second;
} else {
return NULL;
}
}
// Return a pointer to the specified tile cache entry
inline FGTileEntry *get_tile( const SGBucket& b ) const {
return get_tile( b.gen_index() );
}
// Return the cache size
inline size_t get_size() const { return tile_cache.size(); }
// External linear traversal of cache
inline void reset_traversal() { current = tile_cache.begin(); }
inline bool at_end() { return current == tile_cache.end(); }
inline FGTileEntry *get_current() const {
// cout << "index = " << current->first << endl;
return current->second;
}
inline void next() { ++current; }
inline int get_max_cache_size() const { return max_cache_size; }
inline void set_max_cache_size( int m ) { max_cache_size = m; }
/**
* Create a new tile and enqueue it for loading.
* @param b
* @return success/failure
*/
bool insert_tile( FGTileEntry* e );
};
#endif // _NEWCACHE_HXX