/************************************************************************** * tilecache.c -- 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) **************************************************************************/ #include #ifdef HAVE_WINDOWS_H # include #endif #include #include #include #include #include #include
#include "obj.h" #include "tilecache.hxx" /* tile cache */ struct fgTILE tile_cache[FG_TILE_CACHE_SIZE]; /* Initialize the tile cache subsystem */ void fgTileCacheInit( void ) { int i; fgPrintf(FG_TERRAIN, FG_INFO, "Initializing the tile cache.\n"); for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) { tile_cache[i].used = 0; } } /* Search for the specified "bucket" in the cache */ int fgTileCacheExists( struct fgBUCKET *p ) { int i; for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) { if ( tile_cache[i].tile_bucket.lon == p->lon ) { if ( tile_cache[i].tile_bucket.lat == p->lat ) { if ( tile_cache[i].tile_bucket.x == p->x ) { if ( tile_cache[i].tile_bucket.y == p->y ) { fgPrintf( FG_TERRAIN, FG_DEBUG, "TILE EXISTS in cache ... index = %d\n", i ); return( i ); } } } } } return( -1 ); } /* Fill in a tile cache entry with real data for the specified bucket */ void fgTileCacheEntryFillIn( int index, struct fgBUCKET *p ) { fgGENERAL *g; char base_path[256]; char file_name[256]; g = &general; /* Mark this cache entry as used */ tile_cache[index].used = 1; /* Update the bucket */ tile_cache[index].tile_bucket.lon = p->lon; tile_cache[index].tile_bucket.lat = p->lat; tile_cache[index].tile_bucket.x = p->x; tile_cache[index].tile_bucket.y = p->y; /* Load the appropriate area and get the display list pointer */ fgBucketGenBasePath(p, base_path); sprintf(file_name, "%s/Scenery/%s/%ld.obj", g->root_dir, base_path, fgBucketGenIndex(p)); tile_cache[index].display_list = fgObjLoad(file_name, &tile_cache[index].local_ref, &tile_cache[index].bounding_radius); } /* Free a tile cache entry */ void fgTileCacheEntryFree( int index ) { /* Mark this cache entry as un-used */ tile_cache[index].used = 0; /* Update the bucket */ fgPrintf( FG_TERRAIN, FG_DEBUG, "FREEING TILE = (%d %d %d %d)\n", tile_cache[index].tile_bucket.lon, tile_cache[index].tile_bucket.lat, tile_cache[index].tile_bucket.x, tile_cache[index].tile_bucket.y ); /* Load the appropriate area and get the display list pointer */ if ( tile_cache[index].display_list >= 0 ) { xglDeleteLists( tile_cache[index].display_list, 1 ); } } /* Return info for a tile cache entry */ void fgTileCacheEntryInfo( int index, GLint *display_list, struct fgCartesianPoint *local_ref ) { *display_list = tile_cache[index].display_list; /* fgPrintf(FG_TERRAIN, FG_DEBUG, "Display list = %d\n", *display_list); */ local_ref->x = tile_cache[index].local_ref.x; local_ref->y = tile_cache[index].local_ref.y; local_ref->z = tile_cache[index].local_ref.z; } /* Return index of next available slot in tile cache */ int fgTileCacheNextAvail( void ) { struct fgVIEW *v; int i; float dx, dy, dz, max, med, min, tmp; float dist, max_dist; int max_index; v = ¤t_view; max_dist = 0.0; max_index = 0; for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) { if ( tile_cache[i].used == 0 ) { return(i); } else { /* calculate approximate distance from view point */ fgPrintf( FG_TERRAIN, FG_DEBUG, "DIST Abs view pos = %.4f, %.4f, %.4f\n", v->abs_view_pos.x, v->abs_view_pos.y, v->abs_view_pos.z ); fgPrintf( FG_TERRAIN, FG_DEBUG, " ref point = %.4f, %.4f, %.4f\n", tile_cache[i].local_ref.x, tile_cache[i].local_ref.y, tile_cache[i].local_ref.z); dx = fabs(tile_cache[i].local_ref.x - v->abs_view_pos.x); dy = fabs(tile_cache[i].local_ref.y - v->abs_view_pos.y); dz = fabs(tile_cache[i].local_ref.z - v->abs_view_pos.z); max = dx; med = dy; min = dz; if ( max < med ) { tmp = max; max = med; med = tmp; } if ( max < min ) { tmp = max; max = min; min = tmp; } dist = max + (med + min) / 4; fgPrintf( FG_TERRAIN, FG_DEBUG, " distance = %.2f\n", dist); if ( dist > max_dist ) { max_dist = dist; max_index = i; } } } /* 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. */ fgTileCacheEntryFree( max_index ); return( max_index ); } /* $Log$ /* Revision 1.1 1998/04/22 13:22:46 curt /* C++ - ifing the code a bit. /* * Revision 1.11 1998/04/18 04:14:07 curt * Moved fg_debug.c to it's own library. * * Revision 1.10 1998/04/14 02:23:17 curt * Code reorganizations. Added a Lib/ directory for more general libraries. * * Revision 1.9 1998/04/08 23:30:07 curt * Adopted Gnu automake/autoconf system. * * Revision 1.8 1998/04/03 22:11:38 curt * Converting to Gnu autoconf system. * * Revision 1.7 1998/02/01 03:39:55 curt * Minor tweaks. * * Revision 1.6 1998/01/31 00:43:26 curt * Added MetroWorks patches from Carmen Volpe. * * Revision 1.5 1998/01/29 00:51:39 curt * First pass at tile cache, dynamic tile loading and tile unloading now works. * * Revision 1.4 1998/01/27 03:26:43 curt * Playing with new fgPrintf command. * * Revision 1.3 1998/01/27 00:48:03 curt * Incorporated Paul Bleisch's new debug message * system and commandline/config file processing code. * * Revision 1.2 1998/01/26 15:55:24 curt * Progressing on building dynamic scenery system. * * Revision 1.1 1998/01/24 00:03:29 curt * Initial revision. * */