flightgear/Scenery/tilecache.h

/**************************************************************************
 * tilecache.h -- routines to handle scenery tile caching
 *
 * 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.
 *
 * $Id$
 * (Log is kept at end of this file)
 **************************************************************************/


#ifndef _TILECACHE_H
#define _TILECACHE_H


#ifdef WIN32
#  include <windows.h>
#endif

#include <GL/glut.h>
#include <XGL/xgl.h>

#include <Scenery/bucketutils.h>
#include <Include/fg_types.h>

/* For best results ... i.e. to avoid tile load problems and blank areas
 *
 * FG_TILE_CACHE_SIZE >= FG_LOCAL_X_Y + 2*max(FG_LOCAL_X, FG_LOCAL_Y) + 1 */
#define FG_TILE_CACHE_SIZE 100


/* Tile cache record */
struct fgTILE {
    struct fgBUCKET tile_bucket;
    GLint display_list;
    struct fgCartesianPoint local_ref;
    double bounding_radius;
    int used;
    int priority;
};

/* tile cache */
extern struct fgTILE tile_cache[FG_TILE_CACHE_SIZE];


/* Initialize the tile cache subsystem */
void fgTileCacheInit( void );

/* Search for the specified "bucket" in the cache */
int fgTileCacheExists( struct fgBUCKET *p );

/* Return index of next available slot in tile cache */
int fgTileCacheNextAvail( void );

/* Fill in a tile cache entry with real data for the specified bucket */
void fgTileCacheEntryFillIn( int index, struct fgBUCKET *p );

/* Return info for a tile cache entry */
void fgTileCacheEntryInfo( int index, GLint *display_list, 
			   struct fgCartesianPoint *local_ref );


#endif /* _TILECACHE_H */


/* $Log$
/* Revision 1.6  1998/02/18 15:07:10  curt
/* Tweaks to build with SGI OpenGL (and therefor hopefully other accelerated
/* drivers will work.)
/*
 * Revision 1.5  1998/02/16 13:39:45  curt
 * Miscellaneous weekend tweaks.  Fixed? a cache problem that caused whole
 * tiles to occasionally be missing.
 *
 * Revision 1.4  1998/01/31 00:43:27  curt
 * Added MetroWorks patches from Carmen Volpe.
 *
 * Revision 1.3  1998/01/29 00:51:40  curt
 * First pass at tile cache, dynamic tile loading and tile unloading now works.
 *
 * Revision 1.2  1998/01/27 00:48:04  curt
 * Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
 * system and commandline/config file processing code.
 *
 * Revision 1.1  1998/01/24 00:03:29  curt
 * Initial revision.
 *
 */