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.
33 #include <simgear/xgl/xgl.h>
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"
46 #include "tilemgr.hxx" // temp, need to delete later
48 SG_USING_NAMESPACE(std);
52 FGNewCache global_tile_cache;
56 FGNewCache::FGNewCache( void ) {
62 FGNewCache::~FGNewCache( void ) {
66 // Free a tile cache entry
67 void FGNewCache::entry_free( long cache_index ) {
68 SG_LOG( SG_TERRAIN, SG_DEBUG, "FREEING CACHE ENTRY = " << cache_index );
69 FGTileEntry *e = tile_cache[cache_index];
72 tile_cache.erase( cache_index );
76 // Initialize the tile cache subsystem
77 void FGNewCache::init( void ) {
78 // This is a hack that should really get cleaned up at some point
79 extern ssgBranch *terrain;
81 SG_LOG( SG_TERRAIN, SG_INFO, "Initializing the tile cache." );
83 // expand cache if needed. For best results ... i.e. to avoid
84 // tile load problems and blank areas:
85 max_cache_size = 50; // a random number to start with
86 SG_LOG( SG_TERRAIN, SG_INFO, " max cache size = "
88 SG_LOG( SG_TERRAIN, SG_INFO, " current cache size = "
89 << tile_cache.size() );
91 tile_map_iterator current = tile_cache.begin();
92 tile_map_iterator end = tile_cache.end();
94 for ( ; current != end; ++current ) {
95 long index = current->first;
96 SG_LOG( SG_TERRAIN, SG_DEBUG, "clearing " << index );
97 FGTileEntry *e = current->second;
98 e->tile_bucket.make_bad();
102 // and ... just in case we missed something ...
103 terrain->removeAllKids();
105 SG_LOG( SG_TERRAIN, SG_INFO, " done with init()" );
109 // Search for the specified "bucket" in the cache
110 bool FGNewCache::exists( const SGBucket& b ) {
111 long tile_index = b.gen_index();
112 tile_map_iterator it = tile_cache.find( tile_index );
114 return ( it != tile_cache.end() );
118 // Fill in a tile cache entry with real data for the specified bucket
119 void FGNewCache::fill_in( const SGBucket& b ) {
120 SG_LOG( SG_TERRAIN, SG_DEBUG, "FILL IN CACHE ENTRY = " << b.gen_index() );
122 // clear out a distant entry in the cache if needed.
126 FGTileEntry *e = new FGTileEntry( b );
128 // register it in the cache
129 long tile_index = b.gen_index();
130 tile_cache[tile_index] = e;
133 if ( globals->get_fg_scenery() != (string)"" ) {
134 tile_path.set( globals->get_fg_scenery() );
136 tile_path.set( globals->get_fg_root() );
137 tile_path.append( "Scenery" );
140 // Load the appropriate data file
141 e->load( tile_path, true );
145 // Ensure at least one entry is free in the cache
146 void FGNewCache::make_space() {
147 SG_LOG( SG_TERRAIN, SG_DEBUG, "Make space in cache" );
150 SG_LOG( SG_TERRAIN, SG_DEBUG, "cache entries = " << tile_cache.size() );
151 SG_LOG( SG_TERRAIN, SG_DEBUG, "max size = " << max_cache_size );
153 if ( (int)tile_cache.size() < max_cache_size ) {
154 // space in the cache, return
158 while ( (int)tile_cache.size() >= max_cache_size ) {
159 sgdVec3 abs_view_pos;
161 float max_dist = 0.0;
164 // we need to free the furthest entry
165 tile_map_iterator current = tile_cache.begin();
166 tile_map_iterator end = tile_cache.end();
168 for ( ; current != end; ++current ) {
169 long index = current->first;
170 FGTileEntry *e = current->second;
172 // calculate approximate distance from view point
173 sgdCopyVec3( abs_view_pos,
174 globals->get_current_view()->get_abs_view_pos() );
176 SG_LOG( SG_TERRAIN, SG_DEBUG, "DIST Abs view pos = "
177 << abs_view_pos[0] << ","
178 << abs_view_pos[1] << ","
179 << abs_view_pos[2] );
180 SG_LOG( SG_TERRAIN, SG_DEBUG,
181 " ref point = " << e->center );
184 sgdSetVec3( center, e->center.x(), e->center.y(), e->center.z() );
185 dist = sgdDistanceVec3( center, abs_view_pos );
187 SG_LOG( SG_TERRAIN, SG_DEBUG, " distance = " << dist );
189 if ( dist > max_dist ) {
195 // If we made it this far, then there were no open cache entries.
196 // We will instead free the furthest cache entry and return it's
199 if ( max_index >= 0 ) {
200 SG_LOG( SG_TERRAIN, SG_DEBUG, " max_dist = " << max_dist );
201 SG_LOG( SG_TERRAIN, SG_DEBUG, " index = " << max_index );
202 entry_free( max_index );
204 SG_LOG( SG_TERRAIN, SG_ALERT, "WHOOPS!!! Dying in next_avail()" );