-// tilecache.cxx -- routines to handle scenery tile caching
+// TileCache.cxx -- routines to handle scenery tile caching
//
-// Written by Curtis Olson, started January 1998.
+// Written by Curtis Olson, started December 2000.
//
-// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
+// 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
//
// 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.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
-
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
-#ifdef HAVE_WINDOWS_H
-# include <windows.h>
-#endif
+#include <simgear/bucket/newbucket.hxx>
+#include <simgear/debug/logstream.hxx>
+#include <simgear/misc/sg_path.hxx>
-#include <GL/glut.h>
-#include <XGL/xgl.h>
+#include "tileentry.hxx"
+#include "tilecache.hxx"
-#include <ssg.h> // plib include
+TileCache::TileCache( void ) :
+ max_cache_size(100), current_time(0.0)
+{
+ tile_cache.clear();
+}
-#include <Debug/logstream.hxx>
-#include <Airports/genapt.hxx>
-#include <Bucket/newbucket.hxx>
-#include <Main/options.hxx>
-#include <Main/views.hxx>
-#include <Misc/fgpath.hxx>
-#include <Objects/obj.hxx>
-#include "tilecache.hxx"
-#include "tileentry.hxx"
+TileCache::~TileCache( void ) {
+ clear_cache();
+}
-// a cheesy hack (to be fixed later)
-extern ssgBranch *terrain;
-extern ssgEntity *penguin;
+// Free a tile cache entry
+void TileCache::entry_free( long tile_index ) {
+ SG_LOG( SG_TERRAIN, SG_DEBUG, "FREEING CACHE ENTRY = " << tile_index );
+ TileEntry *tile = tile_cache[tile_index];
+ tile->removeFromSceneGraph();
+ tile_cache.erase( tile_index );
+ delete tile;
+}
-// the tile cache
-FGTileCache global_tile_cache;
+// Initialize the tile cache subsystem
+void TileCache::init( void ) {
+ SG_LOG( SG_TERRAIN, SG_INFO, "Initializing the tile cache." );
+ SG_LOG( SG_TERRAIN, SG_INFO, " max cache size = "
+ << max_cache_size );
+ SG_LOG( SG_TERRAIN, SG_INFO, " current cache size = "
+ << tile_cache.size() );
-// Constructor
-FGTileCache::FGTileCache( void ) {
- tile_cache.clear();
+ clear_cache();
+
+ SG_LOG( SG_TERRAIN, SG_INFO, " done with init()" );
}
-// Initialize the tile cache subsystem
-void
-FGTileCache::init( void )
-{
- int i;
-
- FG_LOG( FG_TERRAIN, FG_INFO, "Initializing the tile cache." );
-
- // expand cache if needed. For best results ... i.e. to avoid
- // tile load problems and blank areas:
- //
- // target_cache_size >= (current.options.tile_diameter + 1) ** 2
- //
- int side = current_options.get_tile_diameter() + 2;
- int target_cache_size = (side*side);
- FG_LOG( FG_TERRAIN, FG_DEBUG, " target cache size = "
- << target_cache_size );
- FG_LOG( FG_TERRAIN, FG_DEBUG, " current cache size = "
- << tile_cache.size() );
- FGTileEntry e;
- FG_LOG( FG_TERRAIN, FG_DEBUG, " size of tile = "
- << sizeof( e ) );
- if ( target_cache_size > (int)tile_cache.size() ) {
- // FGTileEntry e;
- e.mark_unused();
- int expansion_amt = target_cache_size - (int)tile_cache.size();
- for ( i = 0; i < expansion_amt; ++i ) {
- tile_cache.push_back( e );
- FG_LOG( FG_TERRAIN, FG_DEBUG, " expanding cache size = "
- << tile_cache.size() );
- }
- }
- FG_LOG( FG_TERRAIN, FG_DEBUG, " done expanding cache, size = "
- << tile_cache.size() );
-
- for ( i = 0; i < (int)tile_cache.size(); i++ ) {
- if ( !tile_cache[i].is_unused() ) {
- entry_free(i);
- }
- tile_cache[i].mark_unused();
- tile_cache[i].tile_bucket.make_bad();
- }
- FG_LOG( FG_TERRAIN, FG_DEBUG, " done with init()" );
+// Search for the specified "bucket" in the cache
+bool TileCache::exists( const SGBucket& b ) const {
+ long tile_index = b.gen_index();
+ const_tile_map_iterator it = tile_cache.find( tile_index );
+
+ return ( it != tile_cache.end() );
}
-// Search for the specified "bucket" in the cache
-int
-FGTileCache::exists( const FGBucket& p )
-{
- int i;
-
- for ( i = 0; i < (int)tile_cache.size(); i++ ) {
- if ( tile_cache[i].tile_bucket == p ) {
- FG_LOG( FG_TERRAIN, FG_DEBUG,
- "TILE EXISTS in cache ... index = " << i );
- return( i );
- }
+// Return the index of a tile to be dropped from the cache, return -1 if
+// nothing available to be removed.
+long TileCache::get_drop_tile() {
+ long min_index = -1;
+ double min_time = DBL_MAX;
+ float priority = FLT_MAX;
+
+ tile_map_iterator current = tile_cache.begin();
+ tile_map_iterator end = tile_cache.end();
+
+ for ( ; current != end; ++current ) {
+ long index = current->first;
+ TileEntry *e = current->second;
+ if (( !e->is_current_view() )&&
+ ( e->is_expired(current_time) ))
+ {
+ if (e->is_expired(current_time - 1.0)&&
+ !e->is_loaded())
+ {
+ /* Immediately drop "empty" tiles which are no longer used/requested, and were last requested > 1 second ago...
+ * Allow a 1 second timeout since an empty tiles may just be loaded...
+ */
+ SG_LOG( SG_TERRAIN, SG_DEBUG, " dropping an unused and empty tile");
+ min_index = index;
+ break;
+ }
+ if (( e->get_time_expired() < min_time )||
+ (( e->get_time_expired() == min_time)&&
+ ( priority > e->get_priority())))
+ {
+ // drop oldest tile with lowest priority
+ min_time = e->get_time_expired();
+ priority = e->get_priority();
+ min_index = index;
+ }
+ }
}
-
- return( -1 );
-}
+ SG_LOG( SG_TERRAIN, SG_DEBUG, " index = " << min_index );
+ SG_LOG( SG_TERRAIN, SG_DEBUG, " min_time = " << min_time );
-// Fill in a tile cache entry with real data for the specified bucket
-void
-FGTileCache::fill_in( int index, const FGBucket& p )
-{
- // Load the appropriate data file and build tile fragment list
- FGPath tile_path( current_options.get_fg_root() );
- tile_path.append( "Scenery" );
- tile_path.append( p.gen_base_path() );
- tile_path.append( p.gen_index_str() );
-
- tile_cache[index].mark_loaded();
- tile_cache[index].tile_bucket = p;
- ssgBranch *new_tile = fgObjLoad( tile_path.str(), &tile_cache[index] );
- tile_cache[index].branch_ptr = new ssgTransform;
- tile_cache[index].branch_ptr->addKid( new_tile );
- tile_cache[index].branch_ptr->addKid( penguin );
- terrain->addKid( tile_cache[index].branch_ptr );
-
- // cout << " ncount before = " << tile_cache[index].ncount << "\n";
- // cout << " fragments before = " << tile_cache[index].fragment_list.size()
- // << "\n";
-
- string apt_path = tile_path.str();
- apt_path += ".apt";
- fgAptGenerate( apt_path, &tile_cache[index] );
-
- // cout << " ncount after = " << tile_cache[index].ncount << "\n";
- // cout << " fragments after = " << tile_cache[index].fragment_list.size()
- // << "\n";
+ return min_index;
}
-// Free a tile cache entry
-void
-FGTileCache::entry_free( int index )
+// Clear all flags indicating tiles belonging to the current view
+void TileCache::clear_current_view()
{
- tile_cache[index].release_fragments();
+ tile_map_iterator current = tile_cache.begin();
+ tile_map_iterator end = tile_cache.end();
+
+ for ( ; current != end; ++current ) {
+ TileEntry *e = current->second;
+ if (e->is_current_view())
+ {
+ // update expiry time for tiles belonging to most recent position
+ e->update_time_expired( current_time );
+ e->set_current_view( false );
+ }
+ }
}
+// Clear a cache entry, note that the cache only holds pointers
+// and this does not free the object which is pointed to.
+void TileCache::clear_entry( long tile_index ) {
+ tile_cache.erase( tile_index );
+}
-// Return index of next available slot in tile cache
-int
-FGTileCache::next_avail( void )
-{
- Point3D delta, abs_view_pos;
- int i;
- float max, med, min, tmp;
- float dist, max_dist;
- int max_index;
-
- max_dist = 0.0;
- max_index = -1;
-
- for ( i = 0; i < (int)tile_cache.size(); i++ ) {
- // only look at freeing NON-scheduled (i.e. ready to load
- // cache entries. This assumes that the cache is always big
- // enough for our tile radius!
-
- if ( tile_cache[i].is_unused() ) {
- // favor unused cache slots
- return(i);
- } else if ( tile_cache[i].is_loaded() ) {
- // calculate approximate distance from view point
- abs_view_pos = current_view.get_abs_view_pos();
-
- FG_LOG( FG_TERRAIN, FG_DEBUG,
- "DIST Abs view pos = " << abs_view_pos );
- FG_LOG( FG_TERRAIN, FG_DEBUG,
- " ref point = " << tile_cache[i].center );
-
- delta.setx( fabs(tile_cache[i].center.x() - abs_view_pos.x() ) );
- delta.sety( fabs(tile_cache[i].center.y() - abs_view_pos.y() ) );
- delta.setz( fabs(tile_cache[i].center.z() - abs_view_pos.z() ) );
-
- max = delta.x(); med = delta.y(); min = delta.z();
- if ( max < med ) {
- tmp = max; max = med; med = tmp;
- }
- if ( max < min ) {
- tmp = max; max = min; min = tmp;
- }
- dist = max + (med + min) / 4;
-
- FG_LOG( FG_TERRAIN, FG_DEBUG, " distance = " << dist );
-
- if ( dist > max_dist ) {
- max_dist = dist;
- max_index = i;
- }
- }
+
+// Clear all completely loaded tiles (ignores partially loaded tiles)
+void TileCache::clear_cache() {
+ std::vector<long> indexList;
+ tile_map_iterator current = tile_cache.begin();
+ tile_map_iterator end = tile_cache.end();
+
+ for ( ; current != end; ++current ) {
+ long index = current->first;
+ SG_LOG( SG_TERRAIN, SG_DEBUG, "clearing " << index );
+ TileEntry *e = current->second;
+ if ( e->is_loaded() ) {
+ e->tile_bucket.make_bad();
+ // entry_free modifies tile_cache, so store index and call entry_free() later;
+ indexList.push_back( index);
+ }
}
+ for (unsigned int it = 0; it < indexList.size(); it++) {
+ entry_free( indexList[ it]);
+ }
+}
+
+/**
+ * Create a new tile and schedule it for loading.
+ */
+bool TileCache::insert_tile( TileEntry *e ) {
+ // register tile in the cache
+ long tile_index = e->get_tile_bucket().gen_index();
+ tile_cache[tile_index] = e;
+ e->update_time_expired(current_time);
- // If we made it this far, then there were no open cache entries.
- // We will instead free the furthest cache entry and return it's
- // index.
-
- entry_free( max_index );
- return( max_index );
+ return true;
}
+/**
+ * Reloads a tile when it's already in memory.
+ */
+void TileCache::refresh_tile(long tile_index)
+{
+ const_tile_map_iterator it = tile_cache.find( tile_index );
+ if ( it == tile_cache.end() )
+ return;
+
+ SG_LOG( SG_TERRAIN, SG_DEBUG, "REFRESHING CACHE ENTRY = " << tile_index );
-// Destructor
-FGTileCache::~FGTileCache( void ) {
+ if (it->second)
+ it->second->refresh();
}
+// update tile's priority and expiry time according to current request
+void TileCache::request_tile(TileEntry* t,float priority,bool current_view,double request_time)
+{
+ if ((!current_view)&&(request_time<=0.0))
+ return;
+
+ // update priority when higher - or old request has expired
+ if ((t->is_expired(current_time))||
+ (priority > t->get_priority()))
+ {
+ t->set_priority( priority );
+ }
+ if (current_view)
+ {
+ t->update_time_expired( current_time );
+ t->set_current_view( true );
+ }
+ else
+ {
+ t->update_time_expired( current_time+request_time );
+ }
+}