org.openstreetmap.josm.data.projection

Class AbstractProjection

java.lang.Object

org.openstreetmap.josm.data.projection.AbstractProjection

All Implemented Interfaces:

Projecting, Projection

Direct Known Subclasses:

CustomProjection

public abstract class AbstractProjection
extends java.lang.Object
implements Projection

Implementation of the Projection interface that represents a coordinate reference system and delegates the real projection and datum conversion to other classes. It handles false easting and northing, central meridian and general scale factor before calling the delegate projection. Forwards lat/lon values to the real projection in units of radians. The fields are named after Proj.4 parameters. Subclasses of AbstractProjection must set ellps and proj to a non-null value. In addition, either datum or nadgrid has to be initialized to some value.

Field Summary

Fields

Modifier and Type	Field and Description
protected Datum	datum
protected Ellipsoid	ellps
protected double	k0
protected double	lon0
protected double	pm
protected Proj	proj
private ProjectionBounds	projectionBoundsBox
protected double	toMeter
protected double	x0
protected double	y0

Constructor Summary

Constructors

Constructor and Description
AbstractProjection()

Method Summary

Modifier and Type	Method and Description
protected static double	convertDegreeMinuteSecond(double degree, double minute, double second)
protected static double	convertMinuteSecond(double minute, double second)
LatLon	eastNorth2latlon(EastNorth en) Convert from easting/norting to lat/lon.
private LatLon	eastNorth2latlon(EastNorth en, java.util.function.DoubleUnaryOperator normalizeLon)
LatLon	eastNorth2latlonClamped(EastNorth en) Convert a east/north coordinate to the LatLon coordinate.
Projection	getBaseProjection() Gets the base projection instance used.
double	getCentralMeridian() Gets the meridian that this projection is centered on.
Datum	getDatum() Gets the datum this projection is based on.
double	getDefaultZoomInPPD() The default scale factor in east/north units per pixel (NavigatableComponent.getState())).
Ellipsoid	getEllipsoid() Get the base ellipsoid that this projection uses.
abstract java.lang.Integer	getEpsgCode()
double	getFalseEasting() Gets an east offset that gets applied when converting the coordinate
double	getFalseNorthing() Gets an north offset that gets applied when converting the coordinate
Proj	getProj() Replies the projection (in the narrow sense)
java.util.Map<ProjectionBounds,Projecting>	getProjectingsForArea(ProjectionBounds area) Returns an map or (subarea, projecting) paris that contains projecting instances to convert the coordinates inside the given area.
double	getScaleFactor()
double	getToMeter() Get the factor that converts meters to intended units of east/north coordinates.
ProjectionBounds	getWorldBoundsBoxEastNorth() Get an approximate EastNorth box around the lat/lon world bounds.
EastNorth	latlon2eastNorth(ILatLon toConvert) Convert from lat/lon to easting/northing.
java.lang.String	toCode() Default implementation of toCode().
void	visitOutline(Bounds b, java.util.function.Consumer<EastNorth> visitor) Visit points along the edge of this bounds instance.
private void	visitOutline(Bounds b, int nPoints, java.util.function.Consumer<EastNorth> visitor)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.openstreetmap.josm.data.projection.Projection

getEastNorthBoundsBox, getLatLonBoundsBox, getMetersPerUnit, getWorldBoundsLatLon, switchXY, toString

Methods inherited from interface org.openstreetmap.josm.data.projection.Projecting

getCacheKey, latlon2eastNorth

Field Detail

ellps

protected Ellipsoid ellps

datum

protected Datum datum

proj

protected Proj proj

x0

protected double x0

y0

protected double y0

lon0

protected double lon0

pm

protected double pm

k0

protected double k0

toMeter

protected double toMeter

projectionBoundsBox

private volatile ProjectionBounds projectionBoundsBox

Constructor Detail

AbstractProjection

public AbstractProjection()

Method Detail

getEllipsoid

public final Ellipsoid getEllipsoid()

Get the base ellipsoid that this projection uses.

Returns:

The Ellipsoid

getDatum

public final Datum getDatum()

Gets the datum this projection is based on.

Returns:

The datum

getProj

public final Proj getProj()

Replies the projection (in the narrow sense)

Returns:

The projection object

getFalseEasting

public final double getFalseEasting()

Gets an east offset that gets applied when converting the coordinate

Returns:

The offset to apply in meter

getFalseNorthing

public final double getFalseNorthing()

Gets an north offset that gets applied when converting the coordinate

Returns:

The offset to apply in meter

getCentralMeridian

public final double getCentralMeridian()

Gets the meridian that this projection is centered on.

Returns:

The longitude of the meridian.

getScaleFactor

public final double getScaleFactor()

getToMeter

public final double getToMeter()

Get the factor that converts meters to intended units of east/north coordinates. For projected coordinate systems, the semi-major axis of the ellipsoid is always given in meters, which means the preliminary projection result will be in meters as well. This factor is used to convert to the intended units of east/north coordinates (e.g. feet in the US). For geographic coordinate systems, the preliminary "projection" result will be in degrees, so there is no reason to convert anything and this factor will by 1 by default.

Returns:

factor that converts meters to intended units of east/north coordinates

latlon2eastNorth

public EastNorth latlon2eastNorth(ILatLon toConvert)

Description copied from interface: Projecting

Convert from lat/lon to easting/northing. This method uses the newer ILatLon interface.

Specified by:

latlon2eastNorth in interface Projecting

Parameters:

toConvert - the geographical point to convert (in WGS84 lat/lon)

Returns:

the corresponding east/north coordinates

See Also:

as shorthand.

eastNorth2latlon

public LatLon eastNorth2latlon(EastNorth en)

Description copied from interface: Projection

Convert from easting/norting to lat/lon.

Specified by:

eastNorth2latlon in interface Projection

Parameters:

en - the geographical point to convert (in projected coordinates)

Returns:

the corresponding lat/lon (WGS84)

eastNorth2latlonClamped

public LatLon eastNorth2latlonClamped(EastNorth en)

Description copied from interface: Projecting

Convert a east/north coordinate to the LatLon coordinate. This method clamps the lat/lon coordinate to the nearest point in the world bounds.

Specified by:

eastNorth2latlonClamped in interface Projecting

Parameters:

en - east/north

Returns:

The lat/lon coordinate.

eastNorth2latlon

private LatLon eastNorth2latlon(EastNorth en,
                                java.util.function.DoubleUnaryOperator normalizeLon)

getProjectingsForArea

public java.util.Map<ProjectionBounds,Projecting> getProjectingsForArea(ProjectionBounds area)

Description copied from interface: Projecting

Returns an map or (subarea, projecting) paris that contains projecting instances to convert the coordinates inside the given area. This can be used by projections to support continuous projections. It is possible that the area covered by the map is bigger than the one given as area. There may be holes.

Specified by:

getProjectingsForArea in interface Projecting

Parameters:

area - The base area

Returns:

a map of non-overlapping ProjectionBounds instances mapped to the Projecting object to use for that area.

getDefaultZoomInPPD

public double getDefaultZoomInPPD()

Description copied from interface: Projection

The default scale factor in east/north units per pixel (NavigatableComponent.getState())). FIXME: misnomer

Specified by:

getDefaultZoomInPPD in interface Projection

Returns:

the scale factor

getEpsgCode

public abstract java.lang.Integer getEpsgCode()

Returns:

The EPSG Code of this CRS, null if it doesn't have one.

toCode

public java.lang.String toCode()

Default implementation of toCode(). Should be overridden, if there is no EPSG code for this CRS.

Specified by:

toCode in interface Projection

Returns:

the projection identifier

convertMinuteSecond

protected static final double convertMinuteSecond(double minute,
                                                  double second)

convertDegreeMinuteSecond

protected static final double convertDegreeMinuteSecond(double degree,
                                                        double minute,
                                                        double second)

getWorldBoundsBoxEastNorth

public final ProjectionBounds getWorldBoundsBoxEastNorth()

Description copied from interface: Projection

Get an approximate EastNorth box around the lat/lon world bounds. Note: The projection is only valid within the bounds returned by Projection.getWorldBoundsLatLon(). The lat/lon bounds need not be a rectangular shape in east/north space. This method returns a box that contains this shape.

Specified by:

getWorldBoundsBoxEastNorth in interface Projection

Returns:

EastNorth box around the lat/lon world bounds

getBaseProjection

public Projection getBaseProjection()

Description copied from interface: Projecting

Gets the base projection instance used. This may be the same as this one or a different one if this one is translated in east/north space.

Specified by:

getBaseProjection in interface Projecting

Returns:

The projection.

visitOutline

public void visitOutline(Bounds b,
                         java.util.function.Consumer<EastNorth> visitor)

Description copied from interface: Projection

Visit points along the edge of this bounds instance.

Depending on the shape in east/north space, it may simply visit the 4 corners or (more generally) several points along the curved edges.

Specified by:

visitOutline in interface Projection

Parameters:

b - the lat/lon rectangle to trace

visitor - a function to call for the points on the edge.

visitOutline

private void visitOutline(Bounds b,
                          int nPoints,
                          java.util.function.Consumer<EastNorth> visitor)