*
* 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.
*
* $Id$
**************************************************************************/
+/** \file newbucket.hxx
+ * A class and associated utiltity functions to manage world scenery tiling.
+ *
+ * Tile borders are aligned along circles of latitude and longitude.
+ * All tiles are 1/8 degree of latitude high and their width in degrees
+ * longitude depends on their latitude, adjusted in such a way that
+ * all tiles cover about the same amount of area of the earth surface.
+ */
#ifndef _NEWBUCKET_HXX
#define _NEWBUCKET_HXX
#include <simgear/compiler.h>
#include <simgear/constants.h>
+#include <simgear/math/SGMath.hxx>
-#ifdef FG_HAVE_STD_INCLUDES
-# include <cmath>
-# include <cstdio> // sprintf()
-# include <iostream>
-#else
-# include <math.h>
-# include <stdio.h> // sprintf()
-# include <iostream.h>
-#endif
-
-// I don't understand ... <math.h> or <cmath> should be included
-// already depending on how you defined FG_HAVE_STD_INCLUDES, but I
-// can go ahead and add this -- CLO
-#ifdef __MWERKS__
-# include <math.h> // needed fabs()
-#endif
-
-#include STL_STRING
+#include <cmath>
+#include <string>
+#include <iosfwd>
+#include <vector>
-FG_USING_STD(string);
+// #define NO_DEPRECATED_API
-#if ! defined( FG_HAVE_NATIVE_SGI_COMPILERS )
-FG_USING_STD(ostream);
-#endif
+/**
+ * standard size of a bucket in degrees (1/8 of a degree)
+ */
+#define SG_BUCKET_SPAN 0.125
-
-
-#define SG_BUCKET_SPAN 0.125 // 1/8 of a degree
-#define SG_HALF_BUCKET_SPAN 0.0625 // 1/2 of 1/8 of a degree = 1/16 = 0.0625
-
-class SGBucket;
-ostream& operator<< ( ostream&, const SGBucket& );
-bool operator== ( const SGBucket&, const SGBucket& );
+/**
+ * half of a standard SG_BUCKET_SPAN
+ */
+#define SG_HALF_BUCKET_SPAN ( 0.5 * SG_BUCKET_SPAN )
// return the horizontal tile span factor based on latitude
-inline double sg_bucket_span( double l ) {
+static double sg_bucket_span( double l ) {
if ( l >= 89.0 ) {
- return 360.0;
- } else if ( l >= 88.0 ) {
- return 8.0;
+ return 12.0;
} else if ( l >= 86.0 ) {
return 4.0;
} else if ( l >= 83.0 ) {
return 1.0;
} else if ( l >= -86.0 ) {
return 2.0;
- } else if ( l >= -88.0 ) {
- return 4.0;
} else if ( l >= -89.0 ) {
- return 8.0;
+ return 4.0;
} else {
- return 360.0;
+ return 12.0;
}
}
+/**
+ * A class to manage world scenery tiling.
+ * This class encapsulates the world tiling scheme. It provides ways
+ * to calculate a unique tile index from a lat/lon, and it can provide
+ * information such as the dimensions of a given tile.
+ */
+
class SGBucket {
private:
- double cx, cy; // centerpoint (lon, lat) in degrees of bucket
- int lon; // longitude index (-180 to 179)
- int lat; // latitude index (-90 to 89)
- int x; // x subdivision (0 to 7)
- int y; // y subdivision (0 to 7)
+ short lon; // longitude index (-180 to 179)
+ short lat; // latitude index (-90 to 89)
+ unsigned char x; // x subdivision (0 to 7)
+ unsigned char y; // y subdivision (0 to 7)
+ void innerSet( double dlon, double dlat );
public:
- // default constructor
- inline SGBucket();
-
- // constructor for specified location
- inline SGBucket(const double dlon, const double dlat);
-
- // create an impossible bucket if false
- inline SGBucket(const bool is_good);
-
- // Parse a unique scenery tile index and find the lon, lat, x, and y
- inline SGBucket(const long int bindex);
-
- // default destructor
- inline ~SGBucket();
-
- // Set the bucket params for the specified lat and lon
+ /**
+ * Default constructor, creates an invalid SGBucket
+ */
+ SGBucket();
+
+ /**
+ * Check if this bucket refers to a valid tile, or not.
+ */
+ bool isValid() const;
+
+#ifndef NO_DEPRECATED_API
+ /**
+ * Construct a bucket given a specific location.
+ * @param dlon longitude specified in degrees
+ * @param dlat latitude specified in degrees
+ */
+ SGBucket(const double dlon, const double dlat);
+#endif
+
+ /**
+ * Construct a bucket given a specific location.
+ *
+ * @param geod Geodetic location
+ */
+ SGBucket(const SGGeod& geod);
+
+ /** Construct a bucket given a unique bucket index number.
+ *
+ * @param bindex unique bucket index
+ */
+ SGBucket(const long int bindex);
+
+#ifndef NO_DEPRECATED_API
+ /**
+ * Reset a bucket to represent a new location.
+ *
+ * @param geod New geodetic location
+ */
+ void set_bucket(const SGGeod& geod);
+
+
+ /**
+ * Reset a bucket to represent a new lat and lon
+ * @param dlon longitude specified in degrees
+ * @param dlat latitude specified in degrees
+ */
void set_bucket( double dlon, double dlat );
- void set_bucket( double *lonlat );
-
- // create an impossible bucket
- inline void SGBucket::make_bad( void ) {
- set_bucket(0.0, 0.0);
- lon = -1000;
- }
-
- // Generate the unique scenery tile index for this bucket
- //
- // 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)
-
+#endif
+
+ /**
+ * Create an impossible bucket.
+ * This is useful if you are comparing cur_bucket to last_bucket
+ * and you want to make sure last_bucket starts out as something
+ * impossible.
+ */
+ void make_bad();
+
+ /**
+ * Generate the unique scenery tile index for this bucket
+ *
+ * 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)
+ * @return tile index
+ */
inline long int gen_index() const {
return ((lon + 180) << 14) + ((lat + 90) << 6) + (y << 3) + x;
}
- inline string gen_index_str() const {
- char tmp[20];
- sprintf(tmp, "%ld",
- (((long)lon + 180) << 14) + ((lat + 90) << 6) + (y << 3) + x);
- return (string)tmp;
- }
-
- // Build the path name for this bucket
- string gen_base_path() const;
-
- // return the center lon of a tile
+ /**
+ * Generate the unique scenery tile index for this bucket in ascii
+ * string form.
+ * @return tile index in string form
+ */
+ std::string gen_index_str() const;
+
+ /**
+ * Build the base path name for this bucket.
+ * @return base path in string form
+ */
+ std::string gen_base_path() const;
+
+ /**
+ * @return the center lon of a tile.
+ */
inline double get_center_lon() const {
double span = sg_bucket_span( lat + y / 8.0 + SG_HALF_BUCKET_SPAN );
if ( span >= 1.0 ) {
- return lon + span / 2.0;
+ return lon + get_width() / 2.0;
} else {
- return lon + x * span + span / 2.0;
+ return lon + x * span + get_width() / 2.0;
}
}
- // return the center lat of a tile
+ /**
+ * @return the center lat of a tile.
+ */
inline double get_center_lat() const {
return lat + y / 8.0 + SG_HALF_BUCKET_SPAN;
}
- // return width of the tile in degrees
+ /**
+ * @return the highest (furthest from the equator) latitude of this
+ * tile. This is the top edge for tiles north of the equator, and
+ * the bottom edge for tiles south
+ */
+ double get_highest_lat() const;
+
+ /**
+ * @return the width of the tile in degrees.
+ */
double get_width() const;
- // return height of the tile in degrees
+
+ /**
+ * @return the height of the tile in degrees.
+ */
double get_height() const;
- // return width of the tile in meters
+ /**
+ * @return the width of the tile in meters.
+ */
double get_width_m() const;
- // return height of the tile in meters
+
+ /**
+ * @return the height of the tile in meters.
+ */
double get_height_m() const;
-
- // Informational methods
- inline int get_lon() const { return lon; }
- inline int get_lat() const { return lat; }
+
+ /**
+ * @return the center of the bucket in geodetic coordinates.
+ */
+ SGGeod get_center() const
+ { return SGGeod::fromDeg(get_center_lon(), get_center_lat()); }
+
+ /**
+ * @return the center of the bucket in geodetic coordinates.
+ */
+ SGGeod get_corner(unsigned num) const
+ {
+ double lonFac = ((num + 1) & 2) ? 0.5 : -0.5;
+ double latFac = ((num ) & 2) ? 0.5 : -0.5;
+ return SGGeod::fromDeg(get_center_lon() + lonFac*get_width(),
+ get_center_lat() + latFac*get_height());
+ }
+
+ // Informational methods.
+
+ /**
+ * @return the lon of the lower left corner of
+ * the 1x1 chunk containing this tile.
+ */
+ inline int get_chunk_lon() const { return lon; }
+
+ /**
+ * @return the lat of the lower left corner of
+ * the 1x1 chunk containing this tile.
+ */
+ inline int get_chunk_lat() const { return lat; }
+
+ /**
+ * @return the x coord within the 1x1 degree chunk this tile.
+ */
inline int get_x() const { return x; }
+
+ /**
+ * @return the y coord within the 1x1 degree chunk this tile.
+ */
inline int get_y() const { return y; }
+ /**
+ * @return bucket offset from this by dx,dy
+ */
+ SGBucket sibling(int dx, int dy) const;
+
// friends
- friend ostream& operator<< ( ostream&, const SGBucket& );
+
+ friend std::ostream& operator<< ( std::ostream&, const SGBucket& );
friend bool operator== ( const SGBucket&, const SGBucket& );
};
+inline bool operator!= (const SGBucket& lhs, const SGBucket& rhs)
+ {
+ return !(lhs == rhs);
+ }
-// offset a bucket specified by dlon, dlat by the specified tile units
-// in the X & Y direction
+#ifndef NO_DEPRECATED_API
+/**
+ * \relates SGBucket
+ * Return the bucket which is offset from the specified dlon, dlat by
+ * the specified tile units in the X & Y direction.
+ * @param dlon starting lon in degrees
+ * @param dlat starting lat in degrees
+ * @param x number of bucket units to offset in x (lon) direction
+ * @param y number of bucket units to offset in y (lat) direction
+ * @return offset bucket
+ */
SGBucket sgBucketOffset( double dlon, double dlat, int x, int y );
+#endif
-// calculate the offset between two buckets
+/**
+ * \relates SGBucket
+ * Calculate the offset between two buckets (in quantity of buckets).
+ * @param b1 bucket 1
+ * @param b2 bucket 2
+ * @param dx offset distance (lon) in tile units
+ * @param dy offset distance (lat) in tile units
+ */
void sgBucketDiff( const SGBucket& b1, const SGBucket& b2, int *dx, int *dy );
-inline ostream&
-operator<< ( ostream& out, const SGBucket& b )
-{
- return out << b.lon << ":" << b.x << ", " << b.lat << ":" << b.y;
-}
-
-
+/**
+ * \relates SGBucket
+ * retrieve a list of buckets in the given bounding box
+ * @param min min lon,lat of bounding box in degrees
+ * @param max max lon,lat of bounding box in degrees
+ * @param list standard vector of buckets within the bounding box
+ */
+void sgGetBuckets( const SGGeod& min, const SGGeod& max, std::vector<SGBucket>& list );
+
+/**
+ * Write the bucket lon, lat, x, and y to the output stream.
+ * @param out output stream
+ * @param b bucket
+ */
+std::ostream& operator<< ( std::ostream& out, const SGBucket& b );
+
+/**
+ * Compare two bucket structures for equality.
+ * @param b1 bucket 1
+ * @param b2 bucket 2
+ * @return comparison result
+ */
inline bool
operator== ( const SGBucket& b1, const SGBucket& b2 )
{
projects / simgear.git / blobdiff