1 /**************************************************************************
2 * tilecache.cxx -- 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 <Bucket/bucketutils.h>
39 #include <Debug/fg_debug.h>
40 #include <Main/options.hxx>
41 #include <Main/views.hxx>
44 #include "tilecache.hxx"
48 struct fgTILE tile_cache[FG_TILE_CACHE_SIZE];
51 /* Initialize the tile cache subsystem */
52 void fgTileCacheInit( void ) {
55 fgPrintf(FG_TERRAIN, FG_INFO, "Initializing the tile cache.\n");
57 for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) {
58 tile_cache[i].used = 0;
63 /* Search for the specified "bucket" in the cache */
64 int fgTileCacheExists( struct fgBUCKET *p ) {
67 for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) {
68 if ( tile_cache[i].tile_bucket.lon == p->lon ) {
69 if ( tile_cache[i].tile_bucket.lat == p->lat ) {
70 if ( tile_cache[i].tile_bucket.x == p->x ) {
71 if ( tile_cache[i].tile_bucket.y == p->y ) {
72 fgPrintf( FG_TERRAIN, FG_DEBUG,
73 "TILE EXISTS in cache ... index = %d\n", i );
85 /* Fill in a tile cache entry with real data for the specified bucket */
86 void fgTileCacheEntryFillIn( int index, struct fgBUCKET *p ) {
93 /* Mark this cache entry as used */
94 tile_cache[index].used = 1;
96 /* Update the bucket */
97 tile_cache[index].tile_bucket.lon = p->lon;
98 tile_cache[index].tile_bucket.lat = p->lat;
99 tile_cache[index].tile_bucket.x = p->x;
100 tile_cache[index].tile_bucket.y = p->y;
102 /* Load the appropriate area and get the display list pointer */
103 fgBucketGenBasePath(p, base_path);
104 sprintf(file_name, "%s/Scenery/%s/%ld", o->fg_root,
105 base_path, fgBucketGenIndex(p));
106 tile_cache[index].display_list =
107 fgObjLoad(file_name, &tile_cache[index].local_ref,
108 &tile_cache[index].bounding_radius);
112 /* Free a tile cache entry */
113 void fgTileCacheEntryFree( int index ) {
114 /* Mark this cache entry as un-used */
115 tile_cache[index].used = 0;
117 /* Update the bucket */
118 fgPrintf( FG_TERRAIN, FG_DEBUG,
119 "FREEING TILE = (%d %d %d %d)\n",
120 tile_cache[index].tile_bucket.lon,
121 tile_cache[index].tile_bucket.lat,
122 tile_cache[index].tile_bucket.x,
123 tile_cache[index].tile_bucket.y );
125 /* Load the appropriate area and get the display list pointer */
126 if ( tile_cache[index].display_list >= 0 ) {
127 xglDeleteLists( tile_cache[index].display_list, 1 );
132 /* Return info for a tile cache entry */
133 void fgTileCacheEntryInfo( int index, GLint *display_list,
134 fgCartesianPoint3d *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;
143 *radius = tile_cache[index].bounding_radius;
147 /* Return index of next available slot in tile cache */
148 int fgTileCacheNextAvail( void ) {
151 float dx, dy, dz, max, med, min, tmp;
152 float dist, max_dist;
160 for ( i = 0; i < FG_TILE_CACHE_SIZE; i++ ) {
161 if ( tile_cache[i].used == 0 ) {
164 /* calculate approximate distance from view point */
165 fgPrintf( FG_TERRAIN, FG_DEBUG,
166 "DIST Abs view pos = %.4f, %.4f, %.4f\n",
167 v->abs_view_pos.x, v->abs_view_pos.y, v->abs_view_pos.z );
168 fgPrintf( FG_TERRAIN, FG_DEBUG,
169 " ref point = %.4f, %.4f, %.4f\n",
170 tile_cache[i].local_ref.x, tile_cache[i].local_ref.y,
171 tile_cache[i].local_ref.z);
173 dx = fabs(tile_cache[i].local_ref.x - v->abs_view_pos.x);
174 dy = fabs(tile_cache[i].local_ref.y - v->abs_view_pos.y);
175 dz = fabs(tile_cache[i].local_ref.z - v->abs_view_pos.z);
177 max = dx; med = dy; min = dz;
179 tmp = max; max = med; med = tmp;
182 tmp = max; max = min; min = tmp;
184 dist = max + (med + min) / 4;
186 fgPrintf( FG_TERRAIN, FG_DEBUG, " distance = %.2f\n", dist);
188 if ( dist > max_dist ) {
195 /* If we made it this far, then there were no open cache entries.
196 * We will instead free the furthest cache entry and return it's
199 fgTileCacheEntryFree( max_index );
205 /* Revision 1.8 1998/05/16 13:09:57 curt
206 /* Beginning to add support for view frustum culling.
207 /* Added some temporary code to calculate bouding radius, until the
208 /* scenery generation tools and scenery can be updated.
210 * Revision 1.7 1998/05/13 18:26:41 curt
211 * Root path info moved to fgOPTIONS.
213 * Revision 1.6 1998/05/02 01:52:17 curt
214 * Playing around with texture coordinates.
216 * Revision 1.5 1998/04/30 12:35:31 curt
217 * Added a command line rendering option specify smooth/flat shading.
219 * Revision 1.4 1998/04/28 01:21:43 curt
220 * Tweaked texture parameter calculations to keep the number smaller. This
221 * avoids the "swimming" problem.
222 * Type-ified fgTIME and fgVIEW.
224 * Revision 1.3 1998/04/25 22:06:32 curt
225 * Edited cvs log messages in source files ... bad bad bad!
227 * Revision 1.2 1998/04/24 00:51:08 curt
228 * Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
229 * Tweaked the scenery file extentions to be "file.obj" (uncompressed)
230 * or "file.obz" (compressed.)
232 * Revision 1.1 1998/04/22 13:22:46 curt
233 * C++ - ifing the code a bit.
235 * Revision 1.11 1998/04/18 04:14:07 curt
236 * Moved fg_debug.c to it's own library.
238 * Revision 1.10 1998/04/14 02:23:17 curt
239 * Code reorganizations. Added a Lib/ directory for more general libraries.
241 * Revision 1.9 1998/04/08 23:30:07 curt
242 * Adopted Gnu automake/autoconf system.
244 * Revision 1.8 1998/04/03 22:11:38 curt
245 * Converting to Gnu autoconf system.
247 * Revision 1.7 1998/02/01 03:39:55 curt
250 * Revision 1.6 1998/01/31 00:43:26 curt
251 * Added MetroWorks patches from Carmen Volpe.
253 * Revision 1.5 1998/01/29 00:51:39 curt
254 * First pass at tile cache, dynamic tile loading and tile unloading now works.
256 * Revision 1.4 1998/01/27 03:26:43 curt
257 * Playing with new fgPrintf command.
259 * Revision 1.3 1998/01/27 00:48:03 curt
260 * Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
261 * system and commandline/config file processing code.
263 * Revision 1.2 1998/01/26 15:55:24 curt
264 * Progressing on building dynamic scenery system.
266 * Revision 1.1 1998/01/24 00:03:29 curt