*
* 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 library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
- * 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.
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
**************************************************************************/
# include <simgear_config.h>
#endif
-#include <math.h>
+#include <cmath>
+#include <iostream>
#include <simgear/misc/sg_path.hxx>
+#include <simgear/debug/logstream.hxx>
#include "newbucket.hxx"
// default constructor
-SGBucket::SGBucket() {
+SGBucket::SGBucket() :
+ lon(-1000),
+ lat(-1000),
+ x(0),
+ y(0)
+{
}
+bool SGBucket::isValid() const
+{
+ // The most northerly valid latitude is 89, not 90. There is no tile
+ // whose *bottom* latitude is 90. Similar there is no tile whose left egde
+ // is 180 longitude.
+ return (lon >= -180) &&
+ (lon < 180) &&
+ (lat >= -90) &&
+ (lat < 90) &&
+ (x < 8) && (y < 8);
+}
+
+void SGBucket::make_bad()
+{
+ lon = -1000;
+ lat = -1000;
+}
// 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;
- }
+SGBucket::SGBucket(const SGGeod& geod) {
+ set_bucket(geod.getLongitudeDeg(),
+ geod.getLatitudeDeg());
}
-
// Parse a unique scenery tile index and find the lon, lat, x, and y
SGBucket::SGBucket(const long int bindex) {
long int index = bindex;
x = index;
}
-
-// default destructor
-SGBucket::~SGBucket() {
+/* Calculate the greatest integral value less than
+ * or equal to the given value (floor(x)),
+ * but attribute coordinates close to the boundary to the next
+ * (increasing) integral
+ */
+static int floorWithEpsilon(double x)
+{
+ double diff = x - static_cast<int>(x);
+ if ( (x >= 0.0) || (fabs(diff) < SG_EPSILON) ) {
+ return static_cast<int>(x);
+ } else {
+ return static_cast<int>(x) - 1;
+ }
}
-
// 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 ) {
+void SGBucket::set_bucket( double dlon, double dlat )
+{
+ if ((dlon < -180.0) || (dlon >= 180.0)) {
+ SG_LOG(SG_TERRAIN, SG_WARN, "SGBucket::set_bucket: passed longitude:" << dlon);
+ dlon = SGMiscd::normalizePeriodic(-180.0, 180.0, dlon);
+ }
+
+ if ((dlat < -90.0) || (dlat > 90.0)) {
+ SG_LOG(SG_TERRAIN, SG_WARN, "SGBucket::set_bucket: passed latitude" << dlat);
+ dlat = SGMiscd::clip(dlat, -90.0, 90.0);
+ }
+
//
- // latitude first
+ // longitude 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;
- }
-
+ // we do NOT need to special case lon=180 here, since
+ // normalizePeriodic will never return 180; it will
+ // return -180, which is what we want.
+ lon = floorWithEpsilon(dlon);
+
// 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);
+ if ( span <= 1.0 ) {
+ /* We have more than one tile per degree of
+ * longitude, so we need an x offset.
+ */
+ 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;
+ /* We have one or more degrees per tile,
+ * so we need to find the base longitude
+ * of that tile.
+ *
+ * First we calculate the integral base longitude
+ * (e.g. -85.5 => -86) and then find the greatest
+ * multiple of span that is less than or equal to
+ * that longitude.
+ *
+ * That way, the Greenwich Meridian is always
+ * a tile border.
+ */
+ lon=static_cast<int>(floor(lon / span) * span);
+ x = 0;
}
//
// then latitude
//
- diff = dlat - (double)(int)dlat;
-
- if ( (dlat >= 0) || (fabs(diff) < SG_EPSILON) ) {
- lat = (int)dlat;
+ lat = floorWithEpsilon(dlat);
+
+ // special case when passing in the north pole point (possibly due to
+ // clipping latitude above). Ensures we generate a valid bucket in this
+ // scenario
+ if (lat == 90) {
+ lat = 89;
+ y = 7;
} else {
- lat = (int)dlat - 1;
+ /* Latitude base and offset are easier, as
+ * tiles always are 1/8 degree of latitude wide.
+ */
+ y = (int)((dlat - lat) * 8);
}
- y = (int)((dlat - lat) * 8);
}
+void SGBucket::set_bucket(const SGGeod& geod)
+{
+ set_bucket(geod.getLongitudeDeg(), geod.getLatitudeDeg());
+}
// Build the path name for this bucket
-string SGBucket::gen_base_path() const {
+std::string SGBucket::gen_base_path() const {
// long int index;
int top_lon, top_lat, main_lon, main_lat;
char hem, pole;
main_lat *= -1;
}
- sprintf(raw_path, "%c%03d%c%02d/%c%03d%c%02d",
+ snprintf(raw_path, 256, "%c%03d%c%02d/%c%03d%c%02d",
hem, top_lon, pole, top_lat,
hem, main_lon, pole, main_lat);
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 local_perimeter = local_radius * SGD_2PI;
double degree_width = local_perimeter / 360.0;
- return sg_bucket_span( get_center_lat() ) * degree_width;
+ return get_width() * 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 perimeter = SG_EQUATORIAL_RADIUS_M * SGD_2PI;
double degree_height = perimeter / 360.0;
return SG_BUCKET_SPAN * degree_height;
}
+SGBucket SGBucket::sibling(int dx, int dy) const
+{
+ if (!isValid()) {
+ SG_LOG(SG_TERRAIN, SG_WARN, "SGBucket::sibling: requesting sibling of invalid bucket");
+ return SGBucket();
+ }
+
+ double clat = get_center_lat() + dy * SG_BUCKET_SPAN;
+ // return invalid here instead of clipping, so callers can discard
+ // invalid buckets without having to check if it's an existing one
+ if ((clat < -90.0) || (clat > 90.0)) {
+ return SGBucket();
+ }
+
+ // find the lon span for the new latitude
+ double span = sg_bucket_span( clat );
+
+ double tmp = get_center_lon() + dx * span;
+ tmp = SGMiscd::normalizePeriodic(-180.0, 180.0, tmp);
+ return SGBucket(tmp, clat);
+}
+
+std::string SGBucket::gen_index_str() const
+{
+ char tmp[20];
+ ::snprintf(tmp, 20, "%ld",
+ (((long)lon + 180) << 14) + ((lat + 90) << 6)
+ + (y << 3) + x);
+ return (std::string)tmp;
+}
// 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
#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 ( sg_bucket_span(c1_lat) <= sg_bucket_span(c2_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 = 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
#endif
}
+void sgGetBuckets( const SGGeod& min, const SGGeod& max, std::vector<SGBucket>& list ) {
+ double lon, lat, span;
+
+ for (lat = min.getLatitudeDeg(); lat <= max.getLatitudeDeg(); lat += SG_BUCKET_SPAN) {
+ span = sg_bucket_span( lat );
+ for (lon = min.getLongitudeDeg(); lon <= max.getLongitudeDeg(); lon += span)
+ {
+ SGBucket b(lon, lat);
+ if (!b.isValid()) {
+ continue;
+ }
+
+ list.push_back(b);
+ }
+ }
+}
+
+std::ostream& operator<< ( std::ostream& out, const SGBucket& b )
+{
+ return out << b.lon << ":" << (int)b.x << ", " << b.lat << ":" << (int)b.y;
+}
projects / simgear.git / blobdiff