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flightgear/src/Scenery/tilemgr.hxx
2000-11-02 00:59:39 +00:00

184 lines
4.3 KiB
C++

// tilemgr.hxx -- routines to handle dynamic management of scenery tiles
//
// Written by Curtis Olson, started January 1998.
//
// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
//
// 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 _TILEMGR_HXX
#define _TILEMGR_HXX
#ifndef __cplusplus
# error This library requires C++
#endif
#include <simgear/compiler.h>
#include <list>
#include <plib/ssg.h>
#include <simgear/bucket/newbucket.hxx>
#include "hitlist.hxx"
FG_USING_STD(list);
#define FG_LOCAL_X_Y 81 // max(o->tile_diameter) ** 2
#define FG_SQUARE( X ) ( (X) * (X) )
#if defined(USE_MEM) || defined(WIN32)
# define FG_MEM_COPY(to,from,n) memcpy(to, from, n)
#else
# define FG_MEM_COPY(to,from,n) bcopy(from, to, n)
#endif
// forward declaration
class FGTileEntry;
class FGLoadRec {
public:
FGBucket b;
int cache_index;
};
class FGTileMgr {
private:
// Tile loading state
enum load_state {
Start = 0,
Inited = 1,
Running = 2
};
load_state state;
enum SCROLL_DIRECTION {
SCROLL_INIT = -1,
SCROLL_NONE = 0,
SCROLL_NORTH,
SCROLL_EAST,
SCROLL_SOUTH,
SCROLL_WEST,
};
SCROLL_DIRECTION scroll_direction;
// pending tile load queue
list < FGLoadRec > load_queue;
// initialize the cache
void initialize_queue();
// forced emptying of the queue. This is necessay to keep
// bookeeping straight for the tile_cache -- which actually
// handles all the (de)allocations
void destroy_queue();
FGBucket BucketOffset( int dx, int dy );
// schedule a tile for loading
int sched_tile( const FGBucket& b );
// load a tile
void load_tile( const FGBucket& b, int cache_index );
// schedule a tile row(column) for loading
void scroll( void );
// see comment at prep_ssg_nodes()
void prep_ssg_node( int idx );
// int hitcount;
// sgdVec3 hit_pts [ MAX_HITS ] ;
// ssgEntity *last_hit;
FGHitList hit_list;
FGBucket previous_bucket;
FGBucket current_bucket;
FGBucket pending;
FGTileEntry *current_tile;
// index of current tile in tile cache;
long int tile_index;
int tile_diameter;
// current longitude latitude
double longitude;
double latitude;
double last_longitude;
double last_latitude;
public:
// Constructor
FGTileMgr ( void );
// Destructor
~FGTileMgr ( void );
// Initialize the Tile Manager subsystem
int init( void );
// given the current lon/lat (in degrees), fill in the array of
// local chunks. If the chunk isn't already in the cache, then
// read it from disk.
int update( double lon, double lat );
// Determine scenery altitude. Normally this just happens when we
// render the scene, but we'd also like to be able to do this
// explicitely. lat & lon are in radians. abs_view_pos in
// meters. Returns result in meters.
void my_ssg_los( string s, ssgBranch *branch, sgdMat4 m,
const sgdVec3 p, const sgdVec3 dir, sgdVec3 normal );
void my_ssg_los( ssgBranch *branch, sgdMat4 m,
const sgdVec3 p, const sgdVec3 dir,
FGHitList *list );
bool current_elev_ssg( sgdVec3 abs_view_pos,
sgVec3 view_pos,
double *terrain_elev );
// Prepare the ssg nodes ... for each tile, set it's proper
// transform and update it's range selector based on current
// visibilty
void prep_ssg_nodes( void );
inline int queue_size() const { return load_queue.size(); }
};
// the tile manager
extern FGTileMgr global_tile_mgr;
#endif // _TILEMGR_HXX