+++ /dev/null
-/**************************************************************************
- * areamgr.c -- routines to handle dynamic management of scenery areas
- *
- * Written by Curtis Olson, started October 1997.
- *
- * 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 WIN32
-# include <windows.h>
-#endif
-
-#include <GL/glut.h>
-#include "../XGL/xgl.h"
-
-#include <math.h>
-
-#include "../Include/constants.h"
-/* temporary */
-#include "../Math/fg_random.h"
-
-
-struct ai {
- int lon; /* longitude (-180 to 179) */
- int lat; /* latitude (-90 to 89) */
- int x; /* x (0 to 7) */
- int y; /* y (0 to 7) */
-};
-
-
-/* we're entering into hacking territory here ... what fun. ;-) */
-long int area_array[7][7];
-
-
-/* Generate the unique scenery area index containing the specified
- lon/lat parameters.
-
- The index is constructed as follows:
-
- 9 bits - to represent 360 degrees of longitude (-180 to 179)
- 8 bits - to represent 180 degrees of latitude (-90 to 89)
-
- Each 1 degree by 1 degree area is further broken down into an 8x8
- grid. So we also need:
-
- 3 bits - to represent x (0 to 7)
- 3 bits - to represent y (0 to 7) */
-static long gen_index(struct ai *p) {
- long index = 0;
-
- index = ((p->lon + 180) << 14) + ((p->lat + 90) << 6) + (p->y << 3) + p->x;
- /* printf(" generated index = %ld\n", index); */
-
- return(index);
-}
-
-
-/* Parse a unique scenery area index and find the lon, lat, x, and y */
-static void parse_index(long int index, struct ai *p) {
- p->lon = index >> 14;
- index -= p->lon << 14;
- p->lon -= 180;
-
- p->lat = index >> 6;
- index -= p->lat << 6;
- p->lat -= 90;
-
- p->y = index >> 3;
- index -= p->y << 3;
-
- p->x = index;
-}
-
-
-/* Build a path name from an area index */
-static void gen_path(long int index, char *path) {
- struct ai p;
- int top_lon, top_lat, main_lon, main_lat;
- char hem, pole;
-
- parse_index(index, &p);
-
- path[0] = '\0';
-
- top_lon = p.lon / 10;
- main_lon = p.lon;
- if ( (p.lon < 0) && (top_lon * 10 != p.lon) ) {
- top_lon -= 1;
- main_lon -= 1;
- }
- top_lon *= 10;
- if ( top_lon >= 0 ) {
- hem = 'e';
- } else {
- hem = 'w';
- top_lon *= -1;
- }
- if ( main_lon < 0 ) {
- main_lon *= -1;
- }
-
- top_lat = p.lat / 10;
- main_lat = p.lat;
- if ( (p.lat < 0) && (top_lat * 10 != p.lat) ) {
- top_lat -= 1;
- main_lat -= 1;
- }
- top_lat *= 10;
- if ( top_lat >= 0 ) {
- pole = 'n';
- } else {
- pole = 's';
- top_lat *= -1;
- }
- if ( main_lat < 0 ) {
- main_lat *= -1;
- }
-
- sprintf(path, "%c%03d%c%03d/%c%03d%c%03d/%ld.ter",
- hem, top_lon, pole, top_lat,
- hem, main_lon, pole, main_lat,
- index);
-}
-
-
-/* offset an ai struct by the specified amounts in the X & Y direction */
-static void offset_ai(struct ai *in, struct ai *out, int x, int y) {
- int diff, temp;
- int dist_lat;
-
- out->lon = in->lon;
- out->lat = in->lat;
- out->x = in->x;
- out->y = in->y;
-
- /* do X direction */
- diff = out->x + x;
- /* printf(" reducing x (%d)\n", diff); */
- if ( diff >= 0 ) {
- temp = diff / 8;
- } else if ( diff < -7 ) {
- temp = (diff + 1) / 8 - 1;
- } else {
- temp = diff / 8 - 1;
- }
- out->x = ((diff % 8) + 8) % 8;
- out->lon = ( (out->lon + 180 + 360 + temp) % 360 ) - 180;
-
- /* do Y direction */
- diff = out->y + y;
- /* printf(" reducing x (%d)\n", diff); */
- if ( diff >= 0 ) {
- temp = diff / 8;
- } else if ( diff < -7 ) {
- temp = (diff + 1) / 8 - 1;
- } else {
- temp = diff / 8 - 1;
- }
- out->y = ((diff % 8) + 8) % 8;
- out->lat = out->lat + temp;
-
- if ( out->lat >= 90 ) {
- dist_lat = out->lat - 90;
- /* printf(" +lat = %d +y = %d\n", dist_lat, out->y); */
-
- out->lat = 90 - (dist_lat + 1);
- out->lon = ( (out->lon + 180 + 180) % 360 ) - 180;
- out->y = 7 - out->y;
- }
-
- if ( out->lat < -90 ) {
- dist_lat = -90 - out->lat;
- /* printf(" +lat = %d +y = %d\n", dist_lat, out->y); */
-
- out->lat = -90 + (dist_lat - 1);
- out->lon = ( (out->lon + 180 + 180) % 360 ) - 180;
- out->y = 7 - out->y;
- }
-}
-
-
-/* Given a lat/lon, fill in the local area index array */
-static void gen_idx_array(double lon, double lat) {
- struct ai p1, p2, p3;
- double diff;
- char path[256];
- long int index = 0;
- int i, j;
-
- printf("lon = %.2f lat = %.2f\n", lon, lat);
-
- diff = lon - (double)(int)lon;
- printf("diff = %.2f\n", diff);
- if ( (lon >= 0) || (fabs(diff) < FG_EPSILON) ) {
- p1.lon = (int)lon;
- } else {
- p1.lon = (int)lon - 1;
- }
- printf(" p1.lon = %d\n", p1.lon);
-
- diff = lat - (double)(int)lat;
- printf("diff = %.2f\n", diff);
- if ( (lat >= 0) || (fabs(diff) < FG_EPSILON) ) {
- p1.lat = (int)lat;
- } else {
- p1.lat = (int)lat - 1;
- }
- printf(" p1.lat = %d\n", p1.lat);
-
- p1.x = (lon - p1.lon) * 8;
- p1.y = (lat - p1.lat) * 8;
- printf(" lon,lat = %d,%d x,y index = %d,%d\n",
- p1.lon, p1.lat, p1.x, p1.y);
-
- for ( i = -3; i <= 3; i++ ) {
- for ( j = -3; j <= 3; j++ ) {
- offset_ai(&p1, &p2, i, j);
- printf(" %d %d %d %d\n", p2.lon, p2.lat, p2.x, p2.y);
- area_array[i][j] = gen_index(&p2);
- printf(" generated index = %ld\n", area_array[i][j]);
-
- /* parse_index(area_array[i][j], &p3); */
- /* printf(" %d %d %d %d\n", p3.lon, p3.lat, p3.x, p3.y); */
- gen_path(area_array[i][j], path);
- printf(" path = %s\n\n", path);
- }
- }
-}
-
-
-main() {
- struct ai p1;
- int i, j, index;
- double lon, lat;
-
- fg_srandom();
-
- p1.lon = 180;
- p1.lat = 90;
- p1.x = 7;
- p1.y = 7;
-
- /* printf("Max index = %ld\n", gen_index(&p1)); */
-
- lon = -50.0;
- lat = -50.0;
- gen_idx_array(lon, lat);
-
- lon = 50.0;
- lat = 50.0;
- gen_idx_array(lon, lat);
-
- for ( i = 0; i < 100; i++ ) {
- lon = ( 360.0 * fg_random() ) - 180.0;
- lat = ( 180.0 * fg_random() ) - 90.0;
-
- gen_idx_array(lon, lat);
- }
-}
-
-
-/* $Log$
-/* Revision 1.2 1998/01/07 03:29:29 curt
-/* Given an arbitrary lat/lon, we can now:
-/* generate a unique index for the chunk containing the lat/lon
-/* generate a path name to the chunk file
-/* build a list of the indexes of all the nearby areas.
-/*
- * Revision 1.1 1998/01/07 02:05:48 curt
- * Initial revision.
- * */
-
-
+++ /dev/null
-/**************************************************************************
- * areautils.c -- support routines to handle dynamic management of scenery areas
- *
- * 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 WIN32
-# include <windows.h>
-#endif
-
-#include <GL/glut.h>
-#include "../XGL/xgl.h"
-
-#include <math.h>
-
-#include "areautils.h"
-#include "../Include/constants.h"
-
-
-/* Generate the unique scenery area index containing the specified
- lon/lat parameters.
-
- The index is constructed as follows:
-
- 9 bits - to represent 360 degrees of longitude (-180 to 179)
- 8 bits - to represent 180 degrees of latitude (-90 to 89)
-
- Each 1 degree by 1 degree area is further broken down into an 8x8
- grid. So we also need:
-
- 3 bits - to represent x (0 to 7)
- 3 bits - to represent y (0 to 7) */
-static long gen_index(struct bucket *p) {
- long index = 0;
-
- index = ((p->lon + 180) << 14) + ((p->lat + 90) << 6) + (p->y << 3) + p->x;
- /* printf(" generated index = %ld\n", index); */
-
- return(index);
-}
-
-
-/* Parse a unique scenery area index and find the lon, lat, x, and y */
-static void parse_index(long int index, struct bucket *p) {
- p->lon = index >> 14;
- index -= p->lon << 14;
- p->lon -= 180;
-
- p->lat = index >> 6;
- index -= p->lat << 6;
- p->lat -= 90;
-
- p->y = index >> 3;
- index -= p->y << 3;
-
- p->x = index;
-}
-
-
-/* Build a path name from an area index */
-static void gen_path(long int index, char *path) {
- struct bucket p;
- int top_lon, top_lat, main_lon, main_lat;
- char hem, pole;
-
- parse_index(index, &p);
-
- path[0] = '\0';
-
- top_lon = p.lon / 10;
- main_lon = p.lon;
- if ( (p.lon < 0) && (top_lon * 10 != p.lon) ) {
- top_lon -= 1;
- main_lon -= 1;
- }
- top_lon *= 10;
- if ( top_lon >= 0 ) {
- hem = 'e';
- } else {
- hem = 'w';
- top_lon *= -1;
- }
- if ( main_lon < 0 ) {
- main_lon *= -1;
- }
-
- top_lat = p.lat / 10;
- main_lat = p.lat;
- if ( (p.lat < 0) && (top_lat * 10 != p.lat) ) {
- top_lat -= 1;
- main_lat -= 1;
- }
- top_lat *= 10;
- if ( top_lat >= 0 ) {
- pole = 'n';
- } else {
- pole = 's';
- top_lat *= -1;
- }
- if ( main_lat < 0 ) {
- main_lat *= -1;
- }
-
- sprintf(path, "%c%03d%c%03d/%c%03d%c%03d/%ld.ter",
- hem, top_lon, pole, top_lat,
- hem, main_lon, pole, main_lat,
- index);
-}
-
-
-/* offset an bucket struct by the specified amounts in the X & Y direction */
-static void offset_bucket(struct bucket *in, struct bucket *out, int x, int y) {
- int diff, temp;
- int dist_lat;
-
- out->lon = in->lon;
- out->lat = in->lat;
- out->x = in->x;
- out->y = in->y;
-
- /* do X direction */
- diff = out->x + x;
- /* printf(" reducing x (%d)\n", diff); */
- if ( diff >= 0 ) {
- temp = diff / 8;
- } else if ( diff < -7 ) {
- temp = (diff + 1) / 8 - 1;
- } else {
- temp = diff / 8 - 1;
- }
- out->x = ((diff % 8) + 8) % 8;
- out->lon = ( (out->lon + 180 + 360 + temp) % 360 ) - 180;
-
- /* do Y direction */
- diff = out->y + y;
- /* printf(" reducing x (%d)\n", diff); */
- if ( diff >= 0 ) {
- temp = diff / 8;
- } else if ( diff < -7 ) {
- temp = (diff + 1) / 8 - 1;
- } else {
- temp = diff / 8 - 1;
- }
- out->y = ((diff % 8) + 8) % 8;
- out->lat = out->lat + temp;
-
- if ( out->lat >= 90 ) {
- dist_lat = out->lat - 90;
- /* printf(" +lat = %d +y = %d\n", dist_lat, out->y); */
-
- out->lat = 90 - (dist_lat + 1);
- out->lon = ( (out->lon + 180 + 180) % 360 ) - 180;
- out->y = 7 - out->y;
- }
-
- if ( out->lat < -90 ) {
- dist_lat = -90 - out->lat;
- /* printf(" +lat = %d +y = %d\n", dist_lat, out->y); */
-
- out->lat = -90 + (dist_lat - 1);
- out->lon = ( (out->lon + 180 + 180) % 360 ) - 180;
- out->y = 7 - out->y;
- }
-}
-
-
-/* Given a lat/lon, find the "bucket" or area that it falls within */
-static void find_bucket(double lon, double lat, struct bucket *p) {
- double diff;
-
- diff = lon - (double)(int)lon;
- /* printf("diff = %.2f\n", diff); */
- if ( (lon >= 0) || (fabs(diff) < FG_EPSILON) ) {
- p->lon = (int)lon;
- } else {
- p->lon = (int)lon - 1;
- }
- /* printf(" p->lon = %d\n", p->lon); */
-
- diff = lat - (double)(int)lat;
- /* printf("diff = %.2f\n", diff); */
- if ( (lat >= 0) || (fabs(diff) < FG_EPSILON) ) {
- p->lat = (int)lat;
- } else {
- p->lat = (int)lat - 1;
- }
- /* printf(" p->lat = %d\n", p->lat); */
-
- p->x = (lon - p->lon) * 8;
- p->y = (lat - p->lat) * 8;
- printf("Bucket = lon,lat = %d,%d x,y index = %d,%d\n",
- p->lon, p->lat, p->x, p->y);
-}
-
-
-/* Given a lat/lon, fill in the local area index array */
-static void gen_idx_array(struct bucket *p1, long int *area,
- int width, int height) {
- struct bucket p2;
- int dw, dh, i, j;
-
- dh = height / 2;
- dw = width / 2;
- for ( j = 0; j < height; j++ ) {
- for ( i = 0; i < width; i++ ) {
- offset_bucket(p1, &p2, i - dw, j - dh);
- area[(j*width)+i] = gen_index(&p2);
- printf(" bucket = %d %d %d %d index = %ld\n",
- p2.lon, p2.lat, p2.x, p2.y, area[(j*width)+i]);
- }
- }
-}
-
-
-int main() {
- struct bucket p1;
- long int area[49];
- char path[256];
- double lon, lat;
- int i, j;
-
- p1.lon = 180;
- p1.lat = 90;
- p1.x = 7;
- p1.y = 7;
-
- /* printf("Max index = %ld\n", gen_index(&p1)); */
-
- lon = -50.0;
- lat = -50.0;
- find_bucket(lon, lat, &p1);
- gen_idx_array(&p1, area, 7, 7);
- for ( j = 0; j < 7; j++ ) {
- for ( i = 0; i < 7; i++ ) {
- gen_path(area[(j*7)+i], path);
- printf(" path = %s\n", path);
- }
- }
-
- lon = 50.0;
- lat = 50.0;
- find_bucket(lon, lat, &p1);
- gen_idx_array(&p1, area, 7, 7);
- for ( j = 0; j < 7; j++ ) {
- for ( i = 0; i < 7; i++ ) {
- gen_path(area[(j*7)+i], path);
- printf(" path = %s\n", path);
- }
- }
-
- return(1);
-}
-
-
-/* $Log$
-/* Revision 1.1 1998/01/07 23:23:40 curt
-/* Initial revision.
-/*
- * */
-
-
+++ /dev/null
-/**************************************************************************
- * areautils.h -- support routines to handle dynamic management of scenery areas
- *
- * 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)
- **************************************************************************/
-
-
-struct bucket {
- int lon; /* longitude (-180 to 179) */
- int lat; /* latitude (-90 to 89) */
- int x; /* x (0 to 7) */
- int y; /* y (0 to 7) */
-};
-
-
-/* Generate the unique scenery area index containing the specified
- lon/lat parameters.
-
- The index is constructed as follows:
-
- 9 bits - to represent 360 degrees of longitude (-180 to 179)
- 8 bits - to represent 180 degrees of latitude (-90 to 89)
-
- Each 1 degree by 1 degree area is further broken down into an 8x8
- grid. So we also need:
-
- 3 bits - to represent x (0 to 7)
- 3 bits - to represent y (0 to 7) */
-static long gen_index(struct bucket *p);
-
-
-/* Parse a unique scenery area index and find the lon, lat, x, and y */
-static void parse_index(long int index, struct bucket *p);
-
-
-/* Build a path name from an area index */
-static void gen_path(long int index, char *path);
-
-
-/* offset an bucket struct by the specified amounts in the X & Y direction */
-static void offset_bucket(struct bucket *in, struct bucket *out, int x, int y);
-
-
-/* Given a lat/lon, find the "bucket" or area that it falls within */
-static void find_bucket(double lon, double lat, struct bucket *p);
-
-
-/* Given a lat/lon, fill in the local area index array */
-static void gen_idx_array(struct bucket *p1, long int *area,
- int width, int height);
-
-
-/* $Log$
-/* Revision 1.1 1998/01/07 23:23:40 curt
-/* Initial revision.
-/*
- * */
-
-
--- /dev/null
+/**************************************************************************
+ * tilemgr.c -- routines to handle dynamic management of scenery tiles
+ *
+ * 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 WIN32
+# include <windows.h>
+#endif
+
+#include <GL/glut.h>
+#include "../XGL/xgl.h"
+
+#include "tileutils.h"
+
+#include "../Aircraft/aircraft.h"
+
+
+/* here's where we keep the array of closest (potentially viewable) tiles */
+static long int tile[49];
+
+
+/* Initialize the Tile Manager subsystem */
+void fgTileMgrInit() {
+ printf("Initializing Tile Manager subsystem.\n");
+ /* fgTileCacheInit(); */
+}
+
+
+/* given the current lon/lat, fill in the array of local chunks. If
+ * the chunk isn't already in the cache, then read it from disk. */
+void fgTileMgrUpdate() {
+ struct fgFLIGHT *f;
+ struct bucket p;
+
+ f = ¤t_aircraft.flight;
+
+ find_bucket(FG_Longitude, FG_Latitude, &p);
+ gen_idx_array(&p, tile, 7, 7);
+}
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 23:50:51 curt
+/* "area" renamed to "tile"
+/*
+ * Revision 1.2 1998/01/07 03:29:29 curt
+ * Given an arbitrary lat/lon, we can now:
+ * generate a unique index for the chunk containing the lat/lon
+ * generate a path name to the chunk file
+ * build a list of the indexes of all the nearby areas.
+ *
+ * Revision 1.1 1998/01/07 02:05:48 curt
+ * Initial revision.
+ * */
+
+
--- /dev/null
+/**************************************************************************
+ * tilemgr.h -- routines to handle dynamic management of scenery tiles
+ *
+ * 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)
+ **************************************************************************/
+
+
+/* Initialize the Tile Manager subsystem */
+void fgTileMgrInit();
+
+
+/* given the current lon/lat, fill in the array of local chunks. If
+ * the chunk isn't already in the cache, then read it from disk. */
+void fgTileMgrUpdate();
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 23:50:51 curt
+/* "area" renamed to "tile"
+/*
+ * */
+
+
--- /dev/null
+/**************************************************************************
+ * tileutils.c -- support routines to handle dynamic management of scenery tiles
+ *
+ * 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 <math.h>
+#include <stdio.h>
+
+#include "tileutils.h"
+#include "../Include/constants.h"
+
+
+/* Generate the unique scenery tile index containing the specified
+ lon/lat parameters.
+
+ The index is constructed as follows:
+
+ 9 bits - to represent 360 degrees of longitude (-180 to 179)
+ 8 bits - to represent 180 degrees of latitude (-90 to 89)
+
+ Each 1 degree by 1 degree tile is further broken down into an 8x8
+ grid. So we also need:
+
+ 3 bits - to represent x (0 to 7)
+ 3 bits - to represent y (0 to 7) */
+static long gen_index(struct bucket *p) {
+ long index = 0;
+
+ index = ((p->lon + 180) << 14) + ((p->lat + 90) << 6) + (p->y << 3) + p->x;
+ /* printf(" generated index = %ld\n", index); */
+
+ return(index);
+}
+
+
+/* Parse a unique scenery tile index and find the lon, lat, x, and y */
+static void parse_index(long int index, struct bucket *p) {
+ p->lon = index >> 14;
+ index -= p->lon << 14;
+ p->lon -= 180;
+
+ p->lat = index >> 6;
+ index -= p->lat << 6;
+ p->lat -= 90;
+
+ p->y = index >> 3;
+ index -= p->y << 3;
+
+ p->x = index;
+}
+
+
+/* Build a path name from an tile index */
+void gen_path(long int index, char *path) {
+ struct bucket p;
+ int top_lon, top_lat, main_lon, main_lat;
+ char hem, pole;
+
+ parse_index(index, &p);
+
+ path[0] = '\0';
+
+ top_lon = p.lon / 10;
+ main_lon = p.lon;
+ if ( (p.lon < 0) && (top_lon * 10 != p.lon) ) {
+ top_lon -= 1;
+ main_lon -= 1;
+ }
+ top_lon *= 10;
+ if ( top_lon >= 0 ) {
+ hem = 'e';
+ } else {
+ hem = 'w';
+ top_lon *= -1;
+ }
+ if ( main_lon < 0 ) {
+ main_lon *= -1;
+ }
+
+ top_lat = p.lat / 10;
+ main_lat = p.lat;
+ if ( (p.lat < 0) && (top_lat * 10 != p.lat) ) {
+ top_lat -= 1;
+ main_lat -= 1;
+ }
+ top_lat *= 10;
+ if ( top_lat >= 0 ) {
+ pole = 'n';
+ } else {
+ pole = 's';
+ top_lat *= -1;
+ }
+ if ( main_lat < 0 ) {
+ main_lat *= -1;
+ }
+
+ sprintf(path, "%c%03d%c%03d/%c%03d%c%03d/%ld.ter",
+ hem, top_lon, pole, top_lat,
+ hem, main_lon, pole, main_lat,
+ index);
+}
+
+
+/* offset an bucket struct by the specified amounts in the X & Y direction */
+static void offset_bucket(struct bucket *in, struct bucket *out, int x, int y) {
+ int diff, temp;
+ int dist_lat;
+
+ out->lon = in->lon;
+ out->lat = in->lat;
+ out->x = in->x;
+ out->y = in->y;
+
+ /* do X direction */
+ diff = out->x + x;
+ /* printf(" reducing x (%d)\n", diff); */
+ if ( diff >= 0 ) {
+ temp = diff / 8;
+ } else if ( diff < -7 ) {
+ temp = (diff + 1) / 8 - 1;
+ } else {
+ temp = diff / 8 - 1;
+ }
+ out->x = ((diff % 8) + 8) % 8;
+ out->lon = ( (out->lon + 180 + 360 + temp) % 360 ) - 180;
+
+ /* do Y direction */
+ diff = out->y + y;
+ /* printf(" reducing x (%d)\n", diff); */
+ if ( diff >= 0 ) {
+ temp = diff / 8;
+ } else if ( diff < -7 ) {
+ temp = (diff + 1) / 8 - 1;
+ } else {
+ temp = diff / 8 - 1;
+ }
+ out->y = ((diff % 8) + 8) % 8;
+ out->lat = out->lat + temp;
+
+ if ( out->lat >= 90 ) {
+ dist_lat = out->lat - 90;
+ /* printf(" +lat = %d +y = %d\n", dist_lat, out->y); */
+
+ out->lat = 90 - (dist_lat + 1);
+ out->lon = ( (out->lon + 180 + 180) % 360 ) - 180;
+ out->y = 7 - out->y;
+ }
+
+ if ( out->lat < -90 ) {
+ dist_lat = -90 - out->lat;
+ /* printf(" +lat = %d +y = %d\n", dist_lat, out->y); */
+
+ out->lat = -90 + (dist_lat - 1);
+ out->lon = ( (out->lon + 180 + 180) % 360 ) - 180;
+ out->y = 7 - out->y;
+ }
+}
+
+
+/* Given a lat/lon, find the "bucket" or tile that it falls within */
+void find_bucket(double lon, double lat, struct bucket *p) {
+ double diff;
+
+ diff = lon - (double)(int)lon;
+ /* printf("diff = %.2f\n", diff); */
+ if ( (lon >= 0) || (fabs(diff) < FG_EPSILON) ) {
+ p->lon = (int)lon;
+ } else {
+ p->lon = (int)lon - 1;
+ }
+ /* printf(" p->lon = %d\n", p->lon); */
+
+ diff = lat - (double)(int)lat;
+ /* printf("diff = %.2f\n", diff); */
+ if ( (lat >= 0) || (fabs(diff) < FG_EPSILON) ) {
+ p->lat = (int)lat;
+ } else {
+ p->lat = (int)lat - 1;
+ }
+ /* printf(" p->lat = %d\n", p->lat); */
+
+ p->x = (lon - p->lon) * 8;
+ p->y = (lat - p->lat) * 8;
+ printf("Bucket = lon,lat = %d,%d x,y index = %d,%d\n",
+ p->lon, p->lat, p->x, p->y);
+}
+
+
+/* Given a lat/lon, fill in the local tile index array */
+void gen_idx_array(struct bucket *p1, long int *tile,
+ int width, int height) {
+ struct bucket p2;
+ int dw, dh, i, j;
+
+ dh = height / 2;
+ dw = width / 2;
+ for ( j = 0; j < height; j++ ) {
+ for ( i = 0; i < width; i++ ) {
+ offset_bucket(p1, &p2, i - dw, j - dh);
+ tile[(j*width)+i] = gen_index(&p2);
+ printf(" bucket = %d %d %d %d index = %ld\n",
+ p2.lon, p2.lat, p2.x, p2.y, tile[(j*width)+i]);
+ }
+ }
+}
+
+
+/* sample main for testing
+int main() {
+ struct bucket p1;
+ long int tile[49];
+ char path[256];
+ double lon, lat;
+ int i, j;
+
+ p1.lon = 180;
+ p1.lat = 90;
+ p1.x = 7;
+ p1.y = 7;
+
+ printf("Max index = %ld\n", gen_index(&p1));
+
+ lon = -50.0;
+ lat = -50.0;
+ find_bucket(lon, lat, &p1);
+ gen_idx_array(&p1, tile, 7, 7);
+ for ( j = 0; j < 7; j++ ) {
+ for ( i = 0; i < 7; i++ ) {
+ gen_path(tile[(j*7)+i], path);
+ printf(" path = %s\n", path);
+ }
+ }
+
+ lon = 50.0;
+ lat = 50.0;
+ find_bucket(lon, lat, &p1);
+ gen_idx_array(&p1, tile, 7, 7);
+ for ( j = 0; j < 7; j++ ) {
+ for ( i = 0; i < 7; i++ ) {
+ gen_path(tile[(j*7)+i], path);
+ printf(" path = %s\n", path);
+ }
+ }
+
+ return(1);
+} */
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 23:50:52 curt
+/* "area" renamed to "tile"
+/*
+ * Revision 1.1 1998/01/07 23:23:40 curt
+ * Initial revision.
+ *
+ * */
+
+
--- /dev/null
+/**************************************************************************
+ * tileutils.h -- support routines to handle dynamic management of scenery tiles
+ *
+ * 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)
+ **************************************************************************/
+
+
+struct bucket {
+ int lon; /* longitude (-180 to 179) */
+ int lat; /* latitude (-90 to 89) */
+ int x; /* x (0 to 7) */
+ int y; /* y (0 to 7) */
+};
+
+
+/* Generate the unique scenery tile index containing the specified
+ lon/lat parameters.
+
+ The index is constructed as follows:
+
+ 9 bits - to represent 360 degrees of longitude (-180 to 179)
+ 8 bits - to represent 180 degrees of latitude (-90 to 89)
+
+ Each 1 degree by 1 degree tile is further broken down into an 8x8
+ grid. So we also need:
+
+ 3 bits - to represent x (0 to 7)
+ 3 bits - to represent y (0 to 7) */
+/* static long gen_index(struct bucket *p); */
+
+
+/* Parse a unique scenery tile index and find the lon, lat, x, and y */
+/* static void parse_index(long int index, struct bucket *p); */
+
+
+/* Build a path name from an tile index */
+void gen_path(long int index, char *path);
+
+
+/* offset an bucket struct by the specified amounts in the X & Y direction */
+/* static void offset_bucket(struct bucket *in, struct bucket *out, int x, int y); */
+
+
+/* Given a lat/lon, find the "bucket" or tile that it falls within */
+void find_bucket(double lon, double lat, struct bucket *p);
+
+
+/* Given a lat/lon, fill in the local tile index array */
+void gen_idx_array(struct bucket *p1, long int *tile,
+ int width, int height);
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 23:50:52 curt
+/* "area" renamed to "tile"
+/*
+ * Revision 1.1 1998/01/07 23:23:40 curt
+ * Initial revision.
+ *
+ * */
+
+
projects / flightgear.git / commitdiff