*
* 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.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
**************************************************************************/
#ifdef HAVE_CONFIG_H
-# include <config.h>
+# include <simgear_config.h>
#endif
+#include <cmath>
+#include <cstdio> // some platforms need this for ::snprintf
+#include <iostream>
-#include <math.h>
-
-#include <simgear/fgpath.hxx>
+#include <simgear/misc/sg_path.hxx>
+#include <simgear/debug/logstream.hxx>
#include "newbucket.hxx"
+// default constructor
+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;
+}
+
+#ifndef NO_DEPRECATED_API
+
+// constructor for specified location
+SGBucket::SGBucket(const double dlon, const double dlat) {
+ set_bucket(dlon, dlat);
+}
+#endif
+
+SGBucket::SGBucket(const SGGeod& geod) {
+ innerSet(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;
+
+ lon = index >> 14;
+ index -= lon << 14;
+ lon -= 180;
+
+ lat = index >> 6;
+ index -= lat << 6;
+ lat -= 90;
+
+ y = index >> 3;
+ index -= y << 3;
+
+ x = index;
+}
+
+/* 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)
+{
+ return static_cast<int>(floor(x + SG_EPSILON));
+}
+
+#ifndef NO_DEPRECATED_API
+
+void SGBucket::set_bucket(double dlon, double dlat)
+{
+ innerSet(dlon, dlat);
+}
+
+
+void SGBucket::set_bucket(const SGGeod& geod)
+{
+ innerSet(geod.getLongitudeDeg(), geod.getLatitudeDeg());
+}
+
+#endif
+
+// Set the bucket params for the specified lat and lon
+void SGBucket::innerSet( 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);
+ }
+
+ //
+ // longitude first
+ //
+ double span = sg_bucket_span( dlat );
+ // 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 <= 1.0 ) {
+ /* We have more than one tile per degree of
+ * longitude, so we need an x offset.
+ */
+ x = floorWithEpsilon((dlon - lon) / span);
+ } else {
+ /* 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
+ //
+ 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 {
+ /* Latitude base and offset are easier, as
+ * tiles always are 1/8 degree of latitude wide.
+ */
+ y = floorWithEpsilon((dlat - lat) * 8);
+ }
+}
+
// Build the path name for this bucket
-string FGBucket::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);
- 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;
+}
+
+double SGBucket::get_highest_lat() const
+{
+ unsigned char adjustedY = y;
+ if (lat >= 0) {
+ // tile is north of the equator, so we want the top edge. Add one
+ // to y to achieve this.
+ ++adjustedY;
+ }
+
+ return lat + (adjustedY / 8.0);
+}
+
+
+// return width of the tile in meters. This function is used by the
+// tile-manager to estimate how many tiles are in the view distance, so
+// we care about the smallest width, which occurs at the highest latitude.
+double SGBucket::get_width_m() const
+{
+ double clat_rad = get_highest_lat() * SGD_DEGREES_TO_RADIANS;
+ double cos_lat = cos( clat_rad );
+ if (fabs(cos_lat) < SG_EPSILON) {
+ // happens for polar tiles, since we pass in a latitude of 90
+ // return an arbitrary small value so all tiles are loaded
+ return 10.0;
+ }
+
+ double local_radius = cos_lat * SG_EQUATORIAL_RADIUS_M;
+ double local_perimeter = local_radius * SGD_2PI;
+ double degree_width = local_perimeter / 360.0;
+
+ return get_width() * degree_width;
+}
+
+
+// return height of the tile in meters
+double SGBucket::get_height_m() const {
+ double perimeter = SG_EQUATORIAL_RADIUS_M * SGD_2PI;
+ double degree_height = perimeter / 360.0;
+
+ return SG_BUCKET_SPAN * degree_height;
+}
+
+unsigned int SGBucket::siblings( int dx, int dy, std::vector<SGBucket>& buckets ) const
+{
+ if (!isValid()) {
+ SG_LOG(SG_TERRAIN, SG_WARN, "SGBucket::sibling: requesting sibling of invalid bucket");
+ return 0;
+ }
+
+ double src_span = sg_bucket_span( get_center_lat() );
+
+ 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 0;
+ }
+
+ // find the lon span for the new latitude
+ double trg_span = sg_bucket_span( clat );
+
+ // if target span < src_span, return multiple buckets...
+ if ( trg_span < src_span ) {
+ // calc center longitude of westernmost sibling
+ double start_lon = get_center_lat() - src_span/2 + trg_span/2;
+
+ unsigned int num_buckets = src_span/trg_span;
+ for ( unsigned int x = 0; x < num_buckets; x++ ) {
+ double tmp = start_lon + x * trg_span;
+ tmp = SGMiscd::normalizePeriodic(-180.0, 180.0, tmp);
+
+ SGBucket b;
+ b.innerSet(tmp, clat);
+
+ buckets.push_back( b );
+ }
+ } else {
+ // just return the single sibling
+ double tmp = get_center_lon() + dx * trg_span;
+ tmp = SGMiscd::normalizePeriodic(-180.0, 180.0, tmp);
+
+ SGBucket b;
+ b.innerSet(tmp, clat);
+
+ buckets.push_back( b );
+ }
+
+ return buckets.size();
+}
+
+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);
+
+ SGBucket b;
+ b.innerSet(tmp, clat);
+ return b;
+}
+
+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;
+}
+
+#ifndef NO_DEPRECATED_API
// 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;
return result;
}
-
+#endif
// 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
#endif
}
+void sgGetBuckets( const SGGeod& min, const SGGeod& max, std::vector<SGBucket>& list ) {
+ double lon, lat, span;
+
+ for (lat = min.getLatitudeDeg(); lat < max.getLatitudeDeg()+SG_BUCKET_SPAN; lat += SG_BUCKET_SPAN) {
+ span = sg_bucket_span( lat );
+ for (lon = min.getLongitudeDeg(); lon <= max.getLongitudeDeg(); lon += span)
+ {
+ SGBucket b(SGGeod::fromDeg(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