*
* Written by Curtis L. Olson, started February 1999.
*
- * Copyright (C) 1999 Curtis L. Olson - curt@flightgear.org
+ * Copyright (C) 1999 Curtis L. Olson - http://www.flightgear.org/~curt/
*
- * 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 library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library 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
+ * This library 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.
+ * Library 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.
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
*
* $Id$
**************************************************************************/
#ifdef HAVE_CONFIG_H
-# include <config.h>
+# include <simgear_config.h>
#endif
-
#include <math.h>
-#include <simgear/misc/fgpath.hxx>
+#include <simgear/misc/sg_path.hxx>
#include "newbucket.hxx"
+// default constructor
+SGBucket::SGBucket() {
+}
+
+
+// constructor for specified location
+SGBucket::SGBucket(const double dlon, const double dlat) {
+ set_bucket(dlon, dlat);
+}
+
+
+// create an impossible bucket if false
+SGBucket::SGBucket(const bool is_good) {
+ set_bucket(0.0, 0.0);
+ if ( !is_good ) {
+ lon = -1000;
+ }
+}
+
+
+// Parse a unique scenery tile index and find the lon, lat, x, and y
+SGBucket::SGBucket(const long int bindex) {
+ long int index = bindex;
+
+ lon = index >> 14;
+ index -= lon << 14;
+ lon -= 180;
+
+ lat = index >> 6;
+ index -= lat << 6;
+ lat -= 90;
+
+ y = index >> 3;
+ index -= y << 3;
+
+ x = index;
+}
+
+
+// default destructor
+SGBucket::~SGBucket() {
+}
+
+
+// Set the bucket params for the specified lat and lon
+void SGBucket::set_bucket( double *lonlat ) {
+ set_bucket( lonlat[0], lonlat[1] );
+}
+
+
+// Set the bucket params for the specified lat and lon
+void SGBucket::set_bucket( double dlon, double dlat ) {
+ //
+ // latitude first
+ //
+ double span = sg_bucket_span( dlat );
+ double diff = dlon - (double)(int)dlon;
+
+ // cout << "diff = " << diff << " span = " << span << endl;
+
+ if ( (dlon >= 0) || (fabs(diff) < SG_EPSILON) ) {
+ lon = (int)dlon;
+ } else {
+ lon = (int)dlon - 1;
+ }
+
+ // find subdivision or super lon if needed
+ if ( span < SG_EPSILON ) {
+ // polar cap
+ lon = 0;
+ x = 0;
+ } else if ( span <= 1.0 ) {
+ x = (int)((dlon - lon) / span);
+ } else {
+ if ( (dlon >= 0) || (fabs(diff) < SG_EPSILON) ) {
+ lon = (int)( (int)(lon / span) * span);
+ } else {
+ // cout << " lon = " << lon
+ // << " tmp = " << (int)((lon-1) / span) << endl;
+ lon = (int)( (int)((lon + 1) / span) * span - span);
+ if ( lon < -180 ) {
+ lon = -180;
+ }
+ }
+ x = 0;
+ }
+
+ //
+ // then latitude
+ //
+ diff = dlat - (double)(int)dlat;
+
+ if ( (dlat >= 0) || (fabs(diff) < SG_EPSILON) ) {
+ lat = (int)dlat;
+ } else {
+ lat = (int)dlat - 1;
+ }
+ y = (int)((dlat - lat) * 8);
+}
+
+
// Build the path name for this bucket
-string FGBucket::gen_base_path() const {
+string SGBucket::gen_base_path() const {
// long int index;
int top_lon, top_lat, main_lon, main_lat;
char hem, pole;
hem, top_lon, pole, top_lat,
hem, main_lon, pole, main_lat);
- FGPath path( raw_path );
+ SGPath path( raw_path );
return path.str();
}
+// return width of the tile in degrees
+double SGBucket::get_width() const {
+ return sg_bucket_span( get_center_lat() );
+}
+
+
+// return height of the tile in degrees
+double SGBucket::get_height() const {
+ return SG_BUCKET_SPAN;
+}
+
+
+// return width of the tile in meters
+double SGBucket::get_width_m() const {
+ double clat = (int)get_center_lat();
+ if ( clat > 0 ) {
+ clat = (int)clat + 0.5;
+ } else {
+ clat = (int)clat - 0.5;
+ }
+ double clat_rad = clat * SGD_DEGREES_TO_RADIANS;
+ double cos_lat = cos( clat_rad );
+ double local_radius = cos_lat * SG_EQUATORIAL_RADIUS_M;
+ double local_perimeter = 2.0 * local_radius * SGD_PI;
+ double degree_width = local_perimeter / 360.0;
+
+ return sg_bucket_span( get_center_lat() ) * degree_width;
+}
+
+
+// return height of the tile in meters
+double SGBucket::get_height_m() const {
+ double perimeter = 2.0 * SG_EQUATORIAL_RADIUS_M * SGD_PI;
+ double degree_height = perimeter / 360.0;
+
+ return SG_BUCKET_SPAN * degree_height;
+}
+
+
// find the bucket which is offset by the specified tile units in the
// X & Y direction. We need the current lon and lat to resolve
// ambiguities when going from a wider tile to a narrower one above or
// below. This assumes that we are feeding in
-FGBucket fgBucketOffset( double dlon, double dlat, int dx, int dy ) {
- FGBucket result( dlon, dlat );
- double clat = result.get_center_lat() + dy * FG_BUCKET_SPAN;
+SGBucket sgBucketOffset( double dlon, double dlat, int dx, int dy ) {
+ SGBucket result( dlon, dlat );
+ double clat = result.get_center_lat() + dy * SG_BUCKET_SPAN;
// walk dy units in the lat direction
result.set_bucket( dlon, clat );
// find the lon span for the new latitude
- double span = bucket_span( clat );
+ double span = sg_bucket_span( clat );
// walk dx units in the lon direction
double tmp = dlon + dx * span;
// calculate the offset between two buckets
-void fgBucketDiff( const FGBucket& b1, const FGBucket& b2, int *dx, int *dy ) {
+void sgBucketDiff( const SGBucket& b1, const SGBucket& b2, int *dx, int *dy ) {
// Latitude difference
double c1_lat = b1.get_center_lat();
double diff_lat = c2_lat - c1_lat;
#ifdef HAVE_RINT
- *dy = (int)rint( diff_lat / FG_BUCKET_SPAN );
+ *dy = (int)rint( diff_lat / SG_BUCKET_SPAN );
#else
if ( diff_lat > 0 ) {
- *dy = (int)( diff_lat / FG_BUCKET_SPAN + 0.5 );
+ *dy = (int)( diff_lat / SG_BUCKET_SPAN + 0.5 );
} else {
- *dy = (int)( diff_lat / FG_BUCKET_SPAN - 0.5 );
+ *dy = (int)( diff_lat / SG_BUCKET_SPAN - 0.5 );
}
#endif
// longitude difference
- double c1_lon = b1.get_center_lon();
- double c2_lon = b2.get_center_lon();
- double diff_lon = c2_lon - c1_lon;
- double span;
- if ( bucket_span(c1_lat) <= bucket_span(c2_lat) ) {
- span = bucket_span(c1_lat);
+ double diff_lon=0.0;
+ double span=0.0;
+
+ SGBucket tmp_bucket;
+ // To handle crossing the bucket size boundary
+ // we need to account for different size buckets.
+
+ if ( sg_bucket_span(c1_lat) <= sg_bucket_span(c2_lat) )
+ {
+ span = sg_bucket_span(c1_lat);
} else {
- span = bucket_span(c2_lat);
+ span = sg_bucket_span(c2_lat);
}
+ diff_lon = b2.get_center_lon() - b1.get_center_lon();
+
+ if (diff_lon <0.0)
+ {
+ diff_lon -= b1.get_width()*0.5 + b2.get_width()*0.5 - span;
+ }
+ else
+ {
+ diff_lon += b1.get_width()*0.5 + b2.get_width()*0.5 - span;
+ }
+
+
#ifdef HAVE_RINT
*dx = (int)rint( diff_lon / span );
#else