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flightgear/src/Scenery/FGTileLoader.hxx
curt 4a609646b6 Modified FlightGear/src/Scenery. The tile loader thread no longer adds
a newly loaded tile to the scene graph.  Instead it puts it in a queue
for the tile manager.  I've used your counter_hack to check the loaded
queue and add any tiles to the scene graph.  I was playing around with
the counter_hack so there might be some commented out code, etc.  I also
changed some SG_DEBUGs to SG_INFOs so I could track the tile loading.
2001-04-16 20:03:52 +00:00

141 lines
3.3 KiB
C++

// FGTileLoader - Queue scenery tiles for loading.
//
// Written by Bernie Bright, started March 2001.
//
// Copyright (C) 2001 Bernard Bright - bbright@bigpond.net.au
//
// 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 FG_TILE_LOADER_HXX
#define FG_TILE_LOADER_HXX
#include <simgear/bucket/newbucket.hxx>
#include <simgear/misc/sg_path.hxx>
#ifdef ENABLE_THREADS
# include <simgear/threads/SGThread.hxx>
# include <simgear/threads/SGQueue.hxx>
#endif
// Forward reference.
class FGTileEntry;
/**
* Queues tiles for loading, possibly by a separate thread.
*/
class FGTileLoader
{
public:
/**
* Constructor.
*/
FGTileLoader();
/**
* Destructor.
*/
~FGTileLoader();
/**
* Add a tile to the end of the load queue.
* @param tile The tile to be loaded from disk.
* @param vis Current visibilty (in feet?) (see FGTileMgr::vis).
*/
void add( FGTileEntry* tile );
/**
* The tile loader thread will only load one tile per call to the
* update() method. This is a way to spread out the work of the
* tile loader and slow it down so it is less intrusive. For
* systems built without thead support this is a no-op.
*/
void update();
/**
* Returns whether the load queue is empty (contains no elements).
* @return true if load queue is empty otherwise returns false.
*/
// bool empty() const { return tile_queue.empty(); }
private:
private:
/**
* FIFO queue of tiles to load from data files.
*/
SGBlockingQueue< FGTileEntry* > tile_queue;
/**
* Base name of directory containing tile data file.
*/
SGPath tile_path;
#ifdef ENABLE_THREADS
/**
* Maximum number of threads to create for loading tiles.
*/
enum { MAX_THREADS = 1 };
/**
* This class represents the thread of execution responsible for
* loading a tile.
*/
class LoaderThread : public SGThread
{
public:
LoaderThread( FGTileLoader* l ) : loader(l) {}
~LoaderThread() {}
/**
* Reads the tile from disk.
*/
void run();
private:
FGTileLoader* loader;
private:
// not implemented.
LoaderThread();
LoaderThread( const LoaderThread& );
LoaderThread& operator=( const LoaderThread& );
};
friend class LoaderThread;
/**
* Array of loading threads.
*/
LoaderThread* threads[ MAX_THREADS ];
/**
* Lock and synchronize access to tile queue.
*/
SGMutex mutex;
SGCondition frame_cond;
/**
* Thread cleanup handler.
*/
friend void cleanup_handler( void* );
#endif // ENABLE_THREADS
};
#endif // FG_TILE_LOADER_HXX