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flightgear/Scenery/tilecache.cxx

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7.3 KiB
C++

/**************************************************************************
* tilecache.cxx -- 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)
**************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef HAVE_WINDOWS_H
# include <windows.h>
#endif
#include <GL/glut.h>
#include <XGL/xgl.h>
#include <Include/general.h>
#include <Bucket/bucketutils.h>
#include <Debug/fg_debug.h>
#include <Main/views.hxx>
#include "obj.hxx"
#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", 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 ) {
fgVIEW *v;
int i;
float dx, dy, dz, max, med, min, tmp;
float dist, max_dist;
int max_index;
v = &current_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 1.5 1998/04/30 12:35:31 curt
/* Added a command line rendering option specify smooth/flat shading.
/*
* Revision 1.4 1998/04/28 01:21:43 curt
* Tweaked texture parameter calculations to keep the number smaller. This
* avoids the "swimming" problem.
* Type-ified fgTIME and fgVIEW.
*
* Revision 1.3 1998/04/25 22:06:32 curt
* Edited cvs log messages in source files ... bad bad bad!
*
* Revision 1.2 1998/04/24 00:51:08 curt
* Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
* Tweaked the scenery file extentions to be "file.obj" (uncompressed)
* or "file.obz" (compressed.)
*
* 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 <pbleisch@acm.org> 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.
*
*/