net.java.html.leaflet

Class ICRS

java.lang.Object

net.java.html.leaflet.ICRS

public abstract class ICRS
extends Object

Defines coordinate reference systems for projecting geographical points into pixel (screen) coordinates and back (and to coordinates in other units for WMS services).

Method Summary

Modifier and Type	Method and Description
String	getCode() Retrieves the standard code name of the CRS passed into WMS services (e.g.
static ICRS	getEPSG3395() Rarely used by some commercial tile providers.
static ICRS	getEPSG3857() The most common CRS for online maps, used by almost all free and commercial tile providers.
static ICRS	getEPSG4326() A common CRS among GIS enthusiasts.
IProjection	getProjection() Retrieves the projection that this CRS uses
static ICRS	getSimple() A simple CRS that maps longitude and latitude into x and y directly.
Point	getSize(int zoom) Returns the size of the world in pixels for a particular zoom.
Transformation	getTransformation() Retrieves the transformation that this CRS uses to turn projected coordinates into screen coordinates for a particular tile service.
Point	latLngToPoint(LatLng latlng, int zoom) Projects geographical coordinates on a given zoom into pixel coordinates.
LatLng	pointToLatLng(Point point, int zoom) The inverse of latLngToPoint.
Point	project(LatLng latlng) Projects geographical coordinates into coordinates in units accepted for this CRS (e.g. meters for EPSG:3857, for passing it to WMS services).
double	scale(int zoom) Returns the scale used when transforming projected coordinates into pixel coordinates for a particular zoom.

Methods inherited from class java.lang.Object

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

Method Detail

getEPSG3857

public static ICRS getEPSG3857()

The most common CRS for online maps, used by almost all free and commercial tile providers. Uses Spherical Mercator projection.

Returns:

instance of spherical mercator projection

getSimple

public static ICRS getSimple()

A simple CRS that maps longitude and latitude into x and y directly. May be used for maps of flat surfaces (e.g. game maps). Note that the y axis should still be inverted (going from bottom to top).

Returns:

instance of simple CRS

getEPSG3395

public static ICRS getEPSG3395()

Rarely used by some commercial tile providers. Uses Elliptical Mercator projection.

Returns:

intance of elliptical mercator projection

getEPSG4326

public static ICRS getEPSG4326()

A common CRS among GIS enthusiasts. Uses simple Equirectangular projection.

Returns:

instance of equirectangular projection

latLngToPoint

public Point latLngToPoint(LatLng latlng,
                           int zoom)

Projects geographical coordinates on a given zoom into pixel coordinates.

Parameters:

latlng - geographical coordinates

zoom - zoom level

Returns:

pixel coordinates of geographical coordinates on the given zoom

pointToLatLng

public LatLng pointToLatLng(Point point,
                            int zoom)

The inverse of latLngToPoint. Projects pixel coordinates on a given zoom into geographical coordinates.

Parameters:

point - pixel coordinates

zoom - zoom level

Returns:

geographical coordinates of pixel coordinates on the given zoom

project

public Point project(LatLng latlng)

Projects geographical coordinates into coordinates in units accepted for this CRS (e.g. meters for EPSG:3857, for passing it to WMS services).

Parameters:

latlng - geographical coordinates

Returns:

projected coordinates for this CRS

scale

public double scale(int zoom)

Returns the scale used when transforming projected coordinates into pixel coordinates for a particular zoom. For example, it returns 256 * 2^zoom for Mercator-based CRS.

Parameters:

zoom - zoom level

Returns:

the scale used when transforming projected coordinates into pixel coordinates

getSize

public Point getSize(int zoom)

Returns the size of the world in pixels for a particular zoom.

Parameters:

zoom - zoom level

Returns:

the size of the world in pixels

getProjection

public IProjection getProjection()

Retrieves the projection that this CRS uses

Returns:

Projection that this CRS uses

getTransformation

public Transformation getTransformation()

Retrieves the transformation that this CRS uses to turn projected coordinates into screen coordinates for a particular tile service.

Returns:

transformation that this CRS uses

getCode

public String getCode()

Retrieves the standard code name of the CRS passed into WMS services (e.g. 'EPSG:3857')

Returns:

standard code name of the CRS