Package gov.nasa.worldwind.globe

Class Globe

java.lang.Object

gov.nasa.worldwind.globe.Globe

public class Globe
extends java.lang.Object

Planet or celestial object approximated by a reference ellipsoid and elevation models. Globe expresses its ellipsoidal parameters and elevation values in meters.

Constructor Summary

Constructors

Constructor	Description
Globe(Ellipsoid ellipsoid, GeographicProjection projection)	Constructs a globe with a specified reference ellipsoid and projection.

Method Summary

Modifier and Type	Method	Description
Position	cartesianToGeographic(double x, double y, double z, Position result)	Converts a Cartesian point to a geographic position.
Matrix4	cartesianToLocalTransform(double x, double y, double z, Matrix4 result)
Vec3	geographicToCartesian(double latitude, double longitude, double altitude, Vec3 result)	Converts a geographic position to Cartesian coordinates.
float[]	geographicToCartesianBorder(Sector sector, int numLat, int numLon, float height, Vec3 origin, float[] result)
float[]	geographicToCartesianGrid(Sector sector, int numLat, int numLon, float[] height, float verticalExaggeration, Vec3 origin, float[] result, int offset, int rowStride)
Vec3	geographicToCartesianNormal(double latitude, double longitude, Vec3 result)
Matrix4	geographicToCartesianTransform(double latitude, double longitude, double altitude, Matrix4 result)
double	getEccentricitySquared()	Indicates the eccentricity squared parameter of the globe's ellipsoid.
double	getElevationAtLocation(double latitude, double longitude)	Determine terrain altitude in specified geographic point from elevation model
ElevationModel	getElevationModel()
Ellipsoid	getEllipsoid()	Indicates the reference ellipsoid defining this globe's equatorial radius and polar radius.
double	getEquatorialRadius()	Indicates the radius in meters of the globe's ellipsoid at the equator.
double	getPolarRadius()	Indicates the radius in meters of the globe's ellipsoid at the poles.
GeographicProjection	getProjection()	Indicates the geographic projection used by this globe.
double	getRadiusAt(double latitude, double longitude)	Indicates the radius in meters of the globe's ellipsoid at a specified location.
double	horizonDistance(double height)	Indicates the distance to the globe's horizon from a specified height above the globe's ellipsoid.
boolean	intersect(Line line, Vec3 result)	Computes the first intersection of this globe with a specified line.
void	setElevationModel(ElevationModel elevationModel)
void	setEllipsoid(Ellipsoid ellipsoid)	Sets the reference ellipsoid that defines this globe's equatorial radius and polar radius.
void	setProjection(GeographicProjection projection)	Sets the geographic projection used by this globe.

Methods inherited from class java.lang.Object

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

Constructor Detail

Globe

public Globe(Ellipsoid ellipsoid,
             GeographicProjection projection)

Constructs a globe with a specified reference ellipsoid and projection.

Parameters:

ellipsoid - the reference ellipsoid defining the globe's equatorial radius and polar radius

projection - the geographic projection used by the globe, specifies the globe's Cartesian coordinate system

Throws:

java.lang.IllegalArgumentException - If the ellipsoid is null

Method Detail

getEllipsoid

public Ellipsoid getEllipsoid()

Indicates the reference ellipsoid defining this globe's equatorial radius and polar radius.

Returns:

this globe's reference ellipsoid

setEllipsoid

public void setEllipsoid(Ellipsoid ellipsoid)

Sets the reference ellipsoid that defines this globe's equatorial radius and polar radius.

Parameters:

ellipsoid - the new reference ellipsoid

Throws:

java.lang.IllegalArgumentException - If the ellipsoid is null

getEquatorialRadius

public double getEquatorialRadius()

Indicates the radius in meters of the globe's ellipsoid at the equator.

Returns:

the radius at the equator, in meters.

getPolarRadius

public double getPolarRadius()

Indicates the radius in meters of the globe's ellipsoid at the poles.

Returns:

the radius at the poles, in meters.

getRadiusAt

public double getRadiusAt(double latitude,
                          double longitude)

Indicates the radius in meters of the globe's ellipsoid at a specified location.

Parameters:

latitude - the location's latitude in degrees

longitude - the location's longitude in degrees

Returns:

the radius in meters of the globe's ellipsoid at the specified location

getEccentricitySquared

public double getEccentricitySquared()

Indicates the eccentricity squared parameter of the globe's ellipsoid. This is equivalent to 2*f - f*f, where f is the ellipsoid's flattening parameter.

Returns:

the eccentricity squared parameter of the globe's ellipsoid.

getElevationModel

public ElevationModel getElevationModel()

setElevationModel

public void setElevationModel(ElevationModel elevationModel)

getProjection

public GeographicProjection getProjection()

Indicates the geographic projection used by this globe. The projection specifies this globe's Cartesian coordinate system.

Returns:

the globe's projection

setProjection

public void setProjection(GeographicProjection projection)

Sets the geographic projection used by this globe. The projection specifies this globe's Cartesian coordinate system.

Parameters:

projection - the projection to use

Throws:

java.lang.IllegalArgumentException - if the projection is null

geographicToCartesian

public Vec3 geographicToCartesian(double latitude,
                                  double longitude,
                                  double altitude,
                                  Vec3 result)

Converts a geographic position to Cartesian coordinates. This globe's projection specifies the Cartesian coordinate system.

Parameters:

latitude - the position's latitude in degrees

longitude - the position's longitude in degrees

altitude - the position's altitude in meters

result - a pre-allocated Vec3 in which to store the computed X, Y and Z Cartesian coordinates

Returns:

the result argument, set to the computed Cartesian coordinates

Throws:

java.lang.IllegalArgumentException - if the result is null

geographicToCartesianNormal

public Vec3 geographicToCartesianNormal(double latitude,
                                        double longitude,
                                        Vec3 result)

geographicToCartesianTransform

public Matrix4 geographicToCartesianTransform(double latitude,
                                              double longitude,
                                              double altitude,
                                              Matrix4 result)

geographicToCartesianGrid

public float[] geographicToCartesianGrid(Sector sector,
                                         int numLat,
                                         int numLon,
                                         float[] height,
                                         float verticalExaggeration,
                                         Vec3 origin,
                                         float[] result,
                                         int offset,
                                         int rowStride)

geographicToCartesianBorder

public float[] geographicToCartesianBorder(Sector sector,
                                           int numLat,
                                           int numLon,
                                           float height,
                                           Vec3 origin,
                                           float[] result)

cartesianToGeographic

public Position cartesianToGeographic(double x,
                                      double y,
                                      double z,
                                      Position result)

Converts a Cartesian point to a geographic position. This globe's projection specifies the Cartesian coordinate system.

Parameters:

x - the Cartesian point's X component

y - the Cartesian point's Y component

z - the Cartesian point's Z component

result - a pre-allocated Position in which to store the computed geographic position

Returns:

the result argument, set to the computed geographic position

Throws:

java.lang.IllegalArgumentException - if the result is null

cartesianToLocalTransform

public Matrix4 cartesianToLocalTransform(double x,
                                         double y,
                                         double z,
                                         Matrix4 result)

horizonDistance

public double horizonDistance(double height)

Indicates the distance to the globe's horizon from a specified height above the globe's ellipsoid. The result of this method is undefined if the height is negative.

Parameters:

height - the viewer's height above the globe's ellipsoid in meters

Returns:

the horizon distance in meters

intersect

public boolean intersect(Line line,
                         Vec3 result)

Computes the first intersection of this globe with a specified line. The line is interpreted as a ray; intersection points behind the line's origin are ignored.

Parameters:

line - the line to intersect with this globe

result - a pre-allocated Vec3 in which to return the computed point

Returns:

true if the ray intersects the globe, otherwise false

Throws:

java.lang.IllegalArgumentException - If either argument is null

getElevationAtLocation

public double getElevationAtLocation(double latitude,
                                     double longitude)

Determine terrain altitude in specified geographic point from elevation model

Parameters:

latitude - location latitude

longitude - location longitude

Returns:

Elevation in meters in specified location