1 // newcache.cxx -- routines to handle scenery tile caching
3 // Written by Curtis Olson, started December 2000.
5 // Copyright (C) 2000 Curtis L. Olson - curt@flightgear.org
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
35 #include <plib/ssg.h> // plib include
37 #include <simgear/bucket/newbucket.hxx>
38 #include <simgear/debug/logstream.hxx>
39 #include <simgear/misc/sg_path.hxx>
41 #include <Main/globals.hxx>
42 #include <Scenery/scenery.hxx> // for scenery.center
44 #include "newcache.hxx"
45 #include "tileentry.hxx"
48 SG_USING_NAMESPACE(std);
52 FGNewCache::FGNewCache( void ) {
58 FGNewCache::~FGNewCache( void ) {
62 // Free a tile cache entry
63 void FGNewCache::entry_free( long cache_index ) {
64 SG_LOG( SG_TERRAIN, SG_DEBUG, "FREEING CACHE ENTRY = " << cache_index );
65 FGTileEntry *tile = tile_cache[cache_index];
66 tile->disconnect_ssg_nodes();
68 #ifdef WISH_PLIB_WAS_THREADED
69 tile->sched_removal();
70 #else // plib isn't threaded so we always go here
75 tile_cache.erase( cache_index );
79 // Initialize the tile cache subsystem
80 void FGNewCache::init( void ) {
81 // This is a hack that should really get cleaned up at some point
82 extern ssgBranch *terrain;
84 SG_LOG( SG_TERRAIN, SG_INFO, "Initializing the tile cache." );
86 // expand cache if needed. For best results ... i.e. to avoid
87 // tile load problems and blank areas:
88 max_cache_size = 50; // a random number to start with
89 SG_LOG( SG_TERRAIN, SG_INFO, " max cache size = "
91 SG_LOG( SG_TERRAIN, SG_INFO, " current cache size = "
92 << tile_cache.size() );
94 tile_map_iterator current = tile_cache.begin();
95 tile_map_iterator end = tile_cache.end();
97 for ( ; current != end; ++current ) {
98 long index = current->first;
99 SG_LOG( SG_TERRAIN, SG_DEBUG, "clearing " << index );
100 FGTileEntry *e = current->second;
101 e->tile_bucket.make_bad();
105 // and ... just in case we missed something ...
106 terrain->removeAllKids();
108 SG_LOG( SG_TERRAIN, SG_INFO, " done with init()" );
112 // Search for the specified "bucket" in the cache
113 bool FGNewCache::exists( const SGBucket& b ) const {
114 long tile_index = b.gen_index();
115 const_tile_map_iterator it = tile_cache.find( tile_index );
117 return ( it != tile_cache.end() );
121 // depricated for threading
123 // Fill in a tile cache entry with real data for the specified bucket
124 void FGNewCache::fill_in( const SGBucket& b ) {
125 SG_LOG( SG_TERRAIN, SG_DEBUG, "FILL IN CACHE ENTRY = " << b.gen_index() );
127 // clear out a distant entry in the cache if needed.
131 FGTileEntry *e = new FGTileEntry( b );
133 // register it in the cache
134 long tile_index = b.gen_index();
135 tile_cache[tile_index] = e;
138 if ( globals->get_fg_scenery() != (string)"" ) {
139 tile_path.set( globals->get_fg_scenery() );
141 tile_path.set( globals->get_fg_root() );
142 tile_path.append( "Scenery" );
145 // Load the appropriate data file
146 e->load( tile_path, true );
151 // Ensure at least one entry is free in the cache
152 void FGNewCache::make_space() {
153 SG_LOG( SG_TERRAIN, SG_DEBUG, "Make space in cache" );
154 SG_LOG( SG_TERRAIN, SG_DEBUG, "cache entries = " << tile_cache.size() );
155 SG_LOG( SG_TERRAIN, SG_DEBUG, "max size = " << max_cache_size );
157 if ( (int)tile_cache.size() < max_cache_size ) {
158 // space in the cache, return
162 while ( (int)tile_cache.size() >= max_cache_size ) {
163 sgdVec3 abs_view_pos;
165 float max_dist = 0.0;
168 // we need to free the furthest entry
169 tile_map_iterator current = tile_cache.begin();
170 tile_map_iterator end = tile_cache.end();
172 for ( ; current != end; ++current ) {
173 long index = current->first;
174 FGTileEntry *e = current->second;
176 if ( e->is_loaded() && e->get_pending_models() == 0 ) {
177 // calculate approximate distance from view point
178 sgdCopyVec3( abs_view_pos,
179 globals->get_current_view()->get_abs_view_pos() );
181 SG_LOG( SG_TERRAIN, SG_DEBUG, "DIST Abs view pos = "
182 << abs_view_pos[0] << ","
183 << abs_view_pos[1] << ","
184 << abs_view_pos[2] );
185 SG_LOG( SG_TERRAIN, SG_DEBUG,
186 " ref point = " << e->center );
190 e->center.x(), e->center.y(), e->center.z() );
191 dist = sgdDistanceVec3( center, abs_view_pos );
193 SG_LOG( SG_TERRAIN, SG_DEBUG, " distance = " << dist );
195 if ( dist > max_dist ) {
202 // If we made it this far, then there were no open cache entries.
203 // We will instead free the furthest cache entry and return it's
206 if ( max_index >= 0 ) {
207 SG_LOG( SG_TERRAIN, SG_DEBUG, " max_dist = " << max_dist );
208 SG_LOG( SG_TERRAIN, SG_DEBUG, " index = " << max_index );
209 entry_free( max_index );
211 SG_LOG( SG_TERRAIN, SG_ALERT, "WHOOPS!!! Dying in next_avail()" );
219 * Create a new tile and schedule it for loading.
222 FGNewCache::insert_tile( FGTileEntry *e )
224 // clear out a distant entry in the cache if needed.
227 // register it in the cache
228 long tile_index = e->get_tile_bucket().gen_index();
229 tile_cache[tile_index] = e;