Superclass for all spatial reference systems. More...

#include <srs.h>

Inheritance diagram for gis::srs::Spatial_reference_system:

Public Member Functions
	Spatial_reference_system ()=default

	Spatial_reference_system (const Spatial_reference_system &)=default

	Spatial_reference_system (Spatial_reference_system &&)=default

virtual	~Spatial_reference_system ()=default

virtual Srs_type	srs_type () const =0
	Get the type of spatial reference system: projected, geometric, etc. More...

virtual Spatial_reference_system *	clone ()=0
	Clone the object. More...

virtual Axis_direction	axis_direction (const int axis) const =0
	Retrieve the axis direction of the spatial reference system. More...

virtual double	angular_unit () const =0
	Retrieve the angular unit relative to radians. More...

virtual double	linear_unit () const =0
	Retrieve how long the unit of the spatial reference system is in meters. More...

virtual double	prime_meridian () const =0
	Retrieve the prime meridian relative to Greenwich. More...

virtual bool	can_be_modified_to (const Spatial_reference_system &srs) const =0
	Checks if this SRS can be changed to another SRS without causing computational incompatibilities. More...

virtual std::string	proj4_parameters () const
	Retrieve the proj4 parameter string. More...

virtual bool	has_towgs84 () const =0
	Checks if this SRS has valid Bursa Wolf parameters. More...

virtual bool	is_wgs84_based () const =0
	Checks if this SRS is WGS 84 or a projection based on WGS 84. More...

Detailed Description

Superclass for all spatial reference systems.

Constructor & Destructor Documentation

◆ Spatial_reference_system() [1/3]

gis::srs::Spatial_reference_system::Spatial_reference_system ( )

default

◆ Spatial_reference_system() [2/3]

gis::srs::Spatial_reference_system::Spatial_reference_system ( const Spatial_reference_system & )

default

◆ Spatial_reference_system() [3/3]

gis::srs::Spatial_reference_system::Spatial_reference_system ( Spatial_reference_system && )

default

◆ ~Spatial_reference_system()

virtual gis::srs::Spatial_reference_system::~Spatial_reference_system ( )

virtualdefault

Member Function Documentation

◆ angular_unit()

virtual double gis::srs::Spatial_reference_system::angular_unit ( ) const

pure virtual

Retrieve the angular unit relative to radians.

Returns: Conversion factor.

Implemented in gis::srs::Geographic_srs, and gis::srs::Projected_srs.

◆ axis_direction()

virtual Axis_direction gis::srs::Spatial_reference_system::axis_direction ( const int axis ) const

pure virtual

Retrieve the axis direction of the spatial reference system.

Parameters

axis	axis number, zero indexed

Returns: Axis direction

Implemented in gis::srs::Geographic_srs, and gis::srs::Projected_srs.

◆ can_be_modified_to()

virtual bool gis::srs::Spatial_reference_system::can_be_modified_to ( const Spatial_reference_system & srs ) const

pure virtual

Checks if this SRS can be changed to another SRS without causing computational incompatibilities.

This means checking that all values in the two SRSs that affect computations are the same. The syntax of the SRS definitions may still vary, e.g., by using different names or by having different authority codes.

In some cases, e.g., unknown projection methods, we don't know how to compare the two SRSs. In that case, we fail by saying that the SRSs are not the same.

The operation is not commutative. The SRS parameter is allowed to have a TOWGS84 specification even though this object doesn't. The opposite is not necessarily true. If this object lacks TOWGS84 information, transformation operations are forbidden on this SRS. Adding that possibility changes what computations are available, but it doesn't change the result of any computation that can currently be done.

An SRS that is currently identified as WGS 84 may both add and remove TOWGS84 information as long as the parameters are all 0. Adding a non-all-zero TOWGS84 clause to a WGS 84 SRS is not allowed.

Parameters

srs	The SRS to compare with.

Return values

true	The two SRSs are semantically the same.
false	The two SRSs are semantically different, or we don't know how to compare them.

◆ clone()

virtual Spatial_reference_system * gis::srs::Spatial_reference_system::clone ( )

pure virtual

Clone the object.

Returns: A new Spatial_reference_system object

◆ has_towgs84()

virtual bool gis::srs::Spatial_reference_system::has_towgs84 ( ) const

pure virtual

Checks if this SRS has valid Bursa Wolf parameters.

Return values

true	Transformation parameters are specified.
false	Transformation parameters are not specified.

Implemented in gis::srs::Geographic_srs, and gis::srs::Projected_srs.

◆ is_wgs84_based()

virtual bool gis::srs::Spatial_reference_system::is_wgs84_based ( ) const

pure virtual

Checks if this SRS is WGS 84 or a projection based on WGS 84.

Return values

true	This SRS is WGS 84 or a projection of WGS 84.
false	This SRS is neither WGS 84 or a projection of WGS 84.

Implemented in gis::srs::Geographic_srs, and gis::srs::Projected_srs.

◆ linear_unit()

virtual double gis::srs::Spatial_reference_system::linear_unit ( ) const

pure virtual

Retrieve how long the unit of the spatial reference system is in meters.

Returns: Conversion factor

Implemented in gis::srs::Geographic_srs, and gis::srs::Projected_srs.

◆ prime_meridian()

virtual double gis::srs::Spatial_reference_system::prime_meridian ( ) const

pure virtual

Retrieve the prime meridian relative to Greenwich.

The prime meridian is returned in the angular unit of the SRS. Positive numbers are East of Greenwich.

See also: angular_unit

Returns: Prime meridian.

Implemented in gis::srs::Geographic_srs, and gis::srs::Projected_srs.

◆ proj4_parameters()

virtual std::string gis::srs::Spatial_reference_system::proj4_parameters ( ) const

inlinevirtual

Retrieve the proj4 parameter string.

If the SRS can't be represented as a proj4 parameter string, an empty string is returned.

Returns: Proj4 parameter string or empty string.

Reimplemented in gis::srs::Geographic_srs, gis::srs::Popular_visualisation_pseudo_mercator_srs, gis::srs::Lambert_azimuthal_equal_area_spherical_srs, gis::srs::Equidistant_cylindrical_srs, gis::srs::Equidistant_cylindrical_spherical_srs, gis::srs::Krovak_north_orientated_srs, gis::srs::Lambert_conic_conformal_2sp_michigan_srs, gis::srs::Colombia_urban_srs, gis::srs::Lambert_conic_conformal_1sp_srs, gis::srs::Lambert_conic_conformal_2sp_srs, gis::srs::Lambert_conic_conformal_2sp_belgium_srs, gis::srs::Mercator_variant_a_srs, gis::srs::Mercator_variant_b_srs, gis::srs::Cassini_soldner_srs, gis::srs::Transverse_mercator_srs, gis::srs::Transverse_mercator_south_orientated_srs, gis::srs::Oblique_stereographic_srs, gis::srs::Polar_stereographic_variant_a_srs, gis::srs::New_zealand_map_grid_srs, gis::srs::Hotine_oblique_mercator_variant_a_srs, gis::srs::Laborde_oblique_mercator_srs, gis::srs::Hotine_oblique_mercator_variant_b_srs, gis::srs::Lambert_conic_near_conformal_srs, gis::srs::American_polyconic_srs, gis::srs::Krovak_srs, gis::srs::Lambert_azimuthal_equal_area_srs, gis::srs::Albers_equal_area_srs, gis::srs::Transverse_mercator_zoned_grid_system_srs, gis::srs::Bonne_south_orientated_srs, gis::srs::Polar_stereographic_variant_b_srs, gis::srs::Polar_stereographic_variant_c_srs, gis::srs::Guam_projection_srs, gis::srs::Modified_azimuthal_equidistant_srs, gis::srs::Hyperbolic_cassini_soldner_srs, gis::srs::Lambert_cylindrical_equal_area_spherical_srs, and gis::srs::Lambert_cylindrical_equal_area_srs.

◆ srs_type()

virtual Srs_type gis::srs::Spatial_reference_system::srs_type ( ) const

pure virtual

Get the type of spatial reference system: projected, geometric, etc.

Returns: SRS type

Implemented in gis::srs::Geographic_srs, and gis::srs::Projected_srs.

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

sql/gis/srs/srs.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Spatial_reference_system() [1/3]

◆ Spatial_reference_system() [2/3]

◆ Spatial_reference_system() [3/3]

◆ ~Spatial_reference_system()

Member Function Documentation

◆ angular_unit()

◆ axis_direction()

◆ can_be_modified_to()

◆ clone()

◆ has_towgs84()

◆ is_wgs84_based()

◆ linear_unit()

◆ prime_meridian()

◆ proj4_parameters()

◆ srs_type()