GeoEncode::DecoderWithBoundingBox Class Reference

A class for decoding coordinates within a bounding box. More...

#include <geoencode.h>

Public Member Functions
	DecoderWithBoundingBox (double lat1, double lon1, double lat2, double lon2)
	Create a decoder with a bounding box. More...
bool	decode (const std::string &value, double &lat_ref, double &lon_ref) const
	Decode a coordinate. More...

Private Attributes
double	lon1
	Longitude at western edge of bounding box. More...
double	lon2
	Longitude at eastern edge of bounding box. More...
double	min_lat
	Minimum latitude in bounding box. More...
double	max_lat
	Maximum latitude in bounding box. More...
unsigned char	start1
	First byte of encoded form of coordinates with lon1. More...
unsigned char	start2
	First byte of encoded form of coordinates with lon2. More...
bool	include_poles
	True if either of the poles are included in the range. More...
bool	discontinuous_longitude_range
	Flag; true if the longitude range is discontinuous (ie, goes over the boundary at which longitudes wrap from 360 to 0). More...

Detailed Description

A class for decoding coordinates within a bounding box.

This class aborts decoding if it is easily able to determine that the encoded coordinate supplied is outside the bounding box, avoiding some unnecessary work.

Definition at line 91 of file geoencode.h.

Constructor & Destructor Documentation

DecoderWithBoundingBox()

GeoEncode::DecoderWithBoundingBox::DecoderWithBoundingBox	(	double	lat1,
		double	lon1,
		double	lat2,
		double	lon2
	)

Create a decoder with a bounding box.

The decoder will decode any encoded coordinates which lie inside the bounding box, and return false for any which lie outside the bounding box.

Parameters

lat1	The latitude of the southern edge of the bounding box.
lon1	The longitude of the western edge of the bounding box.
lat2	The latitude of the northern edge of the bounding box.
lon2	The longitude of the eastern edge of the bounding box.

Definition at line 190 of file geoencode.cc.

References calc_latlon_16ths().

Referenced by calc_latlon_16ths().

Member Function Documentation

decode()

bool GeoEncode::DecoderWithBoundingBox::decode	(	const std::string &	value,
		double &	lat_ref,
		double &	lon_ref
	)		const

Decode a coordinate.

Parameters

value	The coordinate to decode.
lat_ref	A reference to a value to return the latitude in.
lon_ref	A reference to a value to return the longitude in.

Returns

true if the coordinate was in the bounding box (in which case, result will have been updated to contain the coordinate), or false if the coordinate is outside the bounding box.

Note; if this returns false, the values of lat_ref and lon_ref may not have been updated, or may have been updated to incorrect values, due to aborting decoding of the coordinate part-way through.

Definition at line 226 of file geoencode.cc.

References GeoEncode::decode().

Member Data Documentation

discontinuous_longitude_range

bool GeoEncode::DecoderWithBoundingBox::discontinuous_longitude_range

private

Flag; true if the longitude range is discontinuous (ie, goes over the boundary at which longitudes wrap from 360 to 0).

Definition at line 123 of file geoencode.h.

include_poles

bool GeoEncode::DecoderWithBoundingBox::include_poles

private

True if either of the poles are included in the range.

Definition at line 118 of file geoencode.h.

lon1

double GeoEncode::DecoderWithBoundingBox::lon1

private

Longitude at western edge of bounding box.

Definition at line 94 of file geoencode.h.

lon2

double GeoEncode::DecoderWithBoundingBox::lon2

private

Longitude at eastern edge of bounding box.

Definition at line 98 of file geoencode.h.

max_lat

double GeoEncode::DecoderWithBoundingBox::max_lat

private

Maximum latitude in bounding box.

Definition at line 106 of file geoencode.h.

min_lat

double GeoEncode::DecoderWithBoundingBox::min_lat

private

Minimum latitude in bounding box.

Definition at line 102 of file geoencode.h.

start1

unsigned char GeoEncode::DecoderWithBoundingBox::start1

private

First byte of encoded form of coordinates with lon1.

Definition at line 110 of file geoencode.h.

start2

unsigned char GeoEncode::DecoderWithBoundingBox::start2

private

First byte of encoded form of coordinates with lon2.

Definition at line 114 of file geoencode.h.

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The documentation for this class was generated from the following files:

• geospatial/geoencode.h
• geospatial/geoencode.cc