1
0
Fork 0
flightgear/src/Scenery/newcache.hxx
curt fe82a3d31f Make the tile loader more tolerant of situations where the cache is full,
but no entries qualify for removal.  It will keep trying to schedule the
tile(s) until an entry frees up.  Entries in the cache do not qualify for
removal if they are in the process of being loaded.
2001-07-20 22:25:12 +00:00

133 lines
3.5 KiB
C++

// newcache.hxx -- routines to handle scenery tile caching
//
// Written by Curtis Olson, started December 2000.
//
// Copyright (C) 2000 Curtis L. Olson - curt@flightgear.org
//
// 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., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
#ifndef _NEWCACHE_HXX
#define _NEWCACHE_HXX
#ifndef __cplusplus
# error This library requires C++
#endif
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef HAVE_WINDOWS_H
# include <windows.h>
#endif
#include <GL/glut.h>
#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;
// Ensure at least one entry is free in the cache
bool make_space();
// Clear all completely loaded tiles (ignores partially loaded tiles)
void clear_cache();
// Fill in a tile cache entry with real data for the specified bucket
// void fill_in( const SGBucket& b );
// Return a pointer to the specified tile cache entry
inline FGTileEntry *get_tile( const long tile_index ) {
tile_map_iterator it = tile_cache.find( tile_index );
if ( it != tile_cache.end() ) {
return it->second;
} else {
return NULL;
}
}
// Return a pointer to the specified tile cache entry
inline FGTileEntry *get_tile( const SGBucket& b ) {
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() {
// 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