1 /**************************************************************************
2 * tilecache.c -- routines to handle scenery tile caching
4 * Written by Curtis Olson, started January 1998.
6 * Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 * (Log is kept at end of this file)
24 **************************************************************************/
38 #include <Include/general.h>
40 #include <Bucket/bucketutils.h>
41 #include <Debug/fg_debug.h>
42 #include <Main/views.hxx>
45 #include "tilecache.hxx"
49 struct fgTILE tile_cache[FG_TILE_CACHE_SIZE];
52 /* Initialize the tile cache subsystem */
53 void fgTileCacheInit( void ) {
56 fgPrintf(FG_TERRAIN, FG_INFO, "Initializing the tile cache.\n");
58 for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) {
59 tile_cache[i].used = 0;
64 /* Search for the specified "bucket" in the cache */
65 int fgTileCacheExists( struct fgBUCKET *p ) {
68 for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) {
69 if ( tile_cache[i].tile_bucket.lon == p->lon ) {
70 if ( tile_cache[i].tile_bucket.lat == p->lat ) {
71 if ( tile_cache[i].tile_bucket.x == p->x ) {
72 if ( tile_cache[i].tile_bucket.y == p->y ) {
73 fgPrintf( FG_TERRAIN, FG_DEBUG,
74 "TILE EXISTS in cache ... index = %d\n", i );
86 /* Fill in a tile cache entry with real data for the specified bucket */
87 void fgTileCacheEntryFillIn( int index, struct fgBUCKET *p ) {
94 /* Mark this cache entry as used */
95 tile_cache[index].used = 1;
97 /* Update the bucket */
98 tile_cache[index].tile_bucket.lon = p->lon;
99 tile_cache[index].tile_bucket.lat = p->lat;
100 tile_cache[index].tile_bucket.x = p->x;
101 tile_cache[index].tile_bucket.y = p->y;
103 /* Load the appropriate area and get the display list pointer */
104 fgBucketGenBasePath(p, base_path);
105 sprintf(file_name, "%s/Scenery/%s/%ld", g->root_dir,
106 base_path, fgBucketGenIndex(p));
107 tile_cache[index].display_list =
108 fgObjLoad(file_name, &tile_cache[index].local_ref,
109 &tile_cache[index].bounding_radius);
113 /* Free a tile cache entry */
114 void fgTileCacheEntryFree( int index ) {
115 /* Mark this cache entry as un-used */
116 tile_cache[index].used = 0;
118 /* Update the bucket */
119 fgPrintf( FG_TERRAIN, FG_DEBUG,
120 "FREEING TILE = (%d %d %d %d)\n",
121 tile_cache[index].tile_bucket.lon,
122 tile_cache[index].tile_bucket.lat,
123 tile_cache[index].tile_bucket.x,
124 tile_cache[index].tile_bucket.y );
126 /* Load the appropriate area and get the display list pointer */
127 if ( tile_cache[index].display_list >= 0 ) {
128 xglDeleteLists( tile_cache[index].display_list, 1 );
133 /* Return info for a tile cache entry */
134 void fgTileCacheEntryInfo( int index, GLint *display_list,
135 struct fgCartesianPoint *local_ref ) {
136 *display_list = tile_cache[index].display_list;
137 /* fgPrintf(FG_TERRAIN, FG_DEBUG, "Display list = %d\n", *display_list); */
139 local_ref->x = tile_cache[index].local_ref.x;
140 local_ref->y = tile_cache[index].local_ref.y;
141 local_ref->z = tile_cache[index].local_ref.z;
145 /* Return index of next available slot in tile cache */
146 int fgTileCacheNextAvail( void ) {
149 float dx, dy, dz, max, med, min, tmp;
150 float dist, max_dist;
158 for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) {
159 if ( tile_cache[i].used == 0 ) {
162 /* calculate approximate distance from view point */
163 fgPrintf( FG_TERRAIN, FG_DEBUG,
164 "DIST Abs view pos = %.4f, %.4f, %.4f\n",
165 v->abs_view_pos.x, v->abs_view_pos.y, v->abs_view_pos.z );
166 fgPrintf( FG_TERRAIN, FG_DEBUG,
167 " ref point = %.4f, %.4f, %.4f\n",
168 tile_cache[i].local_ref.x, tile_cache[i].local_ref.y,
169 tile_cache[i].local_ref.z);
171 dx = fabs(tile_cache[i].local_ref.x - v->abs_view_pos.x);
172 dy = fabs(tile_cache[i].local_ref.y - v->abs_view_pos.y);
173 dz = fabs(tile_cache[i].local_ref.z - v->abs_view_pos.z);
175 max = dx; med = dy; min = dz;
177 tmp = max; max = med; med = tmp;
180 tmp = max; max = min; min = tmp;
182 dist = max + (med + min) / 4;
184 fgPrintf( FG_TERRAIN, FG_DEBUG, " distance = %.2f\n", dist);
186 if ( dist > max_dist ) {
193 /* If we made it this far, then there were no open cache entries.
194 * We will instead free the furthest cache entry and return it's
197 fgTileCacheEntryFree( max_index );
203 /* Revision 1.3 1998/04/25 22:06:32 curt
204 /* Edited cvs log messages in source files ... bad bad bad!
206 * Revision 1.2 1998/04/24 00:51:08 curt
207 * Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
208 * Tweaked the scenery file extentions to be "file.obj" (uncompressed)
209 * or "file.obz" (compressed.)
211 * Revision 1.1 1998/04/22 13:22:46 curt
212 * C++ - ifing the code a bit.
214 * Revision 1.11 1998/04/18 04:14:07 curt
215 * Moved fg_debug.c to it's own library.
217 * Revision 1.10 1998/04/14 02:23:17 curt
218 * Code reorganizations. Added a Lib/ directory for more general libraries.
220 * Revision 1.9 1998/04/08 23:30:07 curt
221 * Adopted Gnu automake/autoconf system.
223 * Revision 1.8 1998/04/03 22:11:38 curt
224 * Converting to Gnu autoconf system.
226 * Revision 1.7 1998/02/01 03:39:55 curt
229 * Revision 1.6 1998/01/31 00:43:26 curt
230 * Added MetroWorks patches from Carmen Volpe.
232 * Revision 1.5 1998/01/29 00:51:39 curt
233 * First pass at tile cache, dynamic tile loading and tile unloading now works.
235 * Revision 1.4 1998/01/27 03:26:43 curt
236 * Playing with new fgPrintf command.
238 * Revision 1.3 1998/01/27 00:48:03 curt
239 * Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
240 * system and commandline/config file processing code.
242 * Revision 1.2 1998/01/26 15:55:24 curt
243 * Progressing on building dynamic scenery system.
245 * Revision 1.1 1998/01/24 00:03:29 curt