gov.nasa.worldwind.globes

Class FlatGlobe

java.lang.Object

gov.nasa.worldwind.avlist.AVListImpl

gov.nasa.worldwind.WWObjectImpl

gov.nasa.worldwind.globes.EllipsoidalGlobe

gov.nasa.worldwind.globes.FlatGlobe

All Implemented Interfaces:

AVList, MessageListener, Extent, Globe, Globe2D, WWObject, java.beans.PropertyChangeListener, java.util.EventListener

Direct Known Subclasses:

EarthFlat

public class FlatGlobe
extends EllipsoidalGlobe
implements Globe2D

Defines a globe represented as a projection onto a plane. The projection type is modifiable. The default projection is Mercator. New projections may be added by extending this class and overriding geodeticToCartesian cartesianToGeodetic.

This globe uses a Cartesian coordinate system in the world plane is located at the origin and has UNIT-Z as normal. The Y axis points to the north pole. The Z axis points up. The X axis completes a right-handed coordinate system, and points east. Latitude and longitude zero are at the origin on y and x respectively. Sea level is at z = zero.

Nested Class Summary

Nested classes/interfaces inherited from class gov.nasa.worldwind.globes.EllipsoidalGlobe

EllipsoidalGlobe.StateKey

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	continuous
protected int	offset
protected Vec4	offsetVector
protected GeographicProjection	projection
static java.lang.String	PROJECTION_LAT_LON Latitude/Longitude projection.
static java.lang.String	PROJECTION_MERCATOR Mercator projection.
static java.lang.String	PROJECTION_MODIFIED_SINUSOIDAL
static java.lang.String	PROJECTION_SINUSOIDAL Sinusoidal projection.

Fields inherited from class gov.nasa.worldwind.globes.EllipsoidalGlobe

egm96, equatorialRadius, es, polarRadius

Constructor Summary

Constructors

Constructor and Description
FlatGlobe(double equatorialRadius, double polarRadius, double es, ElevationModel em) Create a new globe.

Method Summary

Modifier and Type	Method and Description
protected Position	cartesianToGeodetic(Vec4 cart) Compute the geographic position to corresponds to a Cartesian point.
Vec4	computeNorthPointingTangentAtLocation(Angle latitude, Angle longitude) Computes a vector tangent to this globe and pointing toward the north pole.
Vec4	computeSurfaceNormalAtLocation(Angle latitude, Angle longitude) Returns the normal to the Globe at the specified position.
Vec4	computeSurfaceNormalAtPoint(Vec4 point) Returns the normal to the Globe at the specified cartiesian point.
Matrix	computeSurfaceOrientationAtPosition(Angle latitude, Angle longitude, double metersElevation) Returns the cartesian transform matrix that maps model coordinates to a local coordinate system at (latitude, longitude, metersElevation).
protected Vec4	geodeticToCartesian(Angle latitude, Angle longitude, double metersElevation) Maps a position to a flat world Cartesian coordinates.
protected void	geodeticToCartesian(Sector sector, int numLat, int numLon, double[] metersElevation, Vec4[] out) Maps a grid of geographic positions to Cartesian coordinates.
double	getElevation(Angle latitude, Angle longitude) Indicates the elevation at a specified location.
GlobeStateKey	getGlobeStateKey() Returns a typed state key identifying this globe's current configuration.
GlobeStateKey	getGlobeStateKey(DrawContext dc) Returns a typed state key identifying this globe's current configuration.
int	getOffset()
GeographicProjection	getProjection() Indicates the projection used to project the globe onto a plane.
java.lang.Object	getStateKey(DrawContext dc) Returns a state key identifying this globe's current configuration.
protected Intersection[]	intersect(Line line, double equRadius, double polarRadius)
boolean	intersects(Frustum frustum) Determines whether or not this Extent intersects frustum.
boolean	intersects(Line line) Determines whether or not line intersects this Extent.
boolean	intersects(Plane plane) Calculate whether or not this Extent is intersected by plane.
boolean	isContinuous() Indicates whether it makes sense to treat the associated projection as contiguous with itself.
boolean	isPointAboveElevation(Vec4 point, double elevation) Determines whether a point is above a given elevation
void	setContinuous(boolean continuous) Specifies whether to treat the associated projection as contiguous with itself.
void	setOffset(int offset) Indicates an offset to apply to Cartesian points computed by this globe.
void	setProjection(GeographicProjection projection) Specifies the geographic projection for this globe.

Methods inherited from class gov.nasa.worldwind.globes.EllipsoidalGlobe

applyEGMA96Offsets, computeEllipsoidalNormalAtLocation, computeEllipsoidalOrientationAtPosition, computeEllipsoidalPointFromLocation, computeEllipsoidalPointFromPosition, computeEllipsoidalPointFromPosition, computeModelCoordinateOriginTransform, computeModelCoordinateOriginTransform, computePointFromLocation, computePointFromPosition, computePointFromPosition, computePointFromPosition, computePointsFromPositions, computePositionFromEllipsoidalPoint, computePositionFromPoint, computeSurfaceOrientationAtPosition, ellipsoidalToGeodetic, geodeticToEllipsoidal, getCenter, getDiameter, getEccentricitySquared, getEffectiveRadius, getElevationModel, getElevations, getElevations, getEquatorialRadius, getExtent, getIntersectionPosition, getMaxElevation, getMaximumRadius, getMinAndMaxElevations, getMinAndMaxElevations, getMinElevation, getPolarRadius, getProjectedArea, getRadius, getRadiusAt, getRadiusAt, getTessellator, intersect, intersect, intersect, makeElevationModel, setElevationModel, setTessellator, tessellate

Methods inherited from class gov.nasa.worldwind.WWObjectImpl

onMessage, propertyChange

Methods inherited from class gov.nasa.worldwind.avlist.AVListImpl

addPropertyChangeListener, addPropertyChangeListener, clearList, copy, firePropertyChange, firePropertyChange, getBooleanValue, getBooleanValue, getChangeSupport, getDoubleValue, getDoubleValue, getEntries, getIntegerValue, getIntegerValue, getLongValue, getLongValue, getRestorableStateForAVPair, getStringValue, getStringValue, getStringValue, getValue, getValues, hasKey, removeKey, removePropertyChangeListener, removePropertyChangeListener, setValue, setValues

Methods inherited from class java.lang.Object

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

Methods inherited from interface gov.nasa.worldwind.avlist.AVList

addPropertyChangeListener, addPropertyChangeListener, clearList, copy, firePropertyChange, firePropertyChange, getEntries, getStringValue, getValue, getValues, hasKey, removeKey, removePropertyChangeListener, removePropertyChangeListener, setValue, setValues

Methods inherited from interface java.beans.PropertyChangeListener

propertyChange

Methods inherited from interface gov.nasa.worldwind.event.MessageListener

onMessage

Field Detail

continuous

protected boolean continuous

offset

protected int offset

offsetVector

protected Vec4 offsetVector

projection

protected GeographicProjection projection

PROJECTION_LAT_LON

public static final java.lang.String PROJECTION_LAT_LON

Latitude/Longitude projection. Also known as the geographic projection, the equirectangular projection, or the Plate Carree projection.

See Also:

Constant Field Values

PROJECTION_MERCATOR

public static final java.lang.String PROJECTION_MERCATOR

Mercator projection.

See Also:

Constant Field Values

PROJECTION_MODIFIED_SINUSOIDAL

public static final java.lang.String PROJECTION_MODIFIED_SINUSOIDAL

See Also:

Constant Field Values

PROJECTION_SINUSOIDAL

public static final java.lang.String PROJECTION_SINUSOIDAL

Sinusoidal projection.

See Also:

Constant Field Values

Constructor Detail

FlatGlobe

public FlatGlobe(double equatorialRadius,
                 double polarRadius,
                 double es,
                 ElevationModel em)

Create a new globe. The globe will use the Mercator projection. The projection can be changed using setProjection(GeographicProjection).

Parameters:

equatorialRadius - Radius of the globe at the equator.

polarRadius - Radius of the globe at the poles.

es - Square of the globe's eccentricity.

em - Elevation model. May be null.

Method Detail

cartesianToGeodetic

protected Position cartesianToGeodetic(Vec4 cart)

Description copied from class: EllipsoidalGlobe

Compute the geographic position to corresponds to a Cartesian point.

Overrides:

cartesianToGeodetic in class EllipsoidalGlobe

Parameters:

cart - Cartesian point to convert to geographic.

Returns:

The geographic position of cart.

See Also:

EllipsoidalGlobe.geodeticToCartesian(gov.nasa.worldwind.geom.Angle, gov.nasa.worldwind.geom.Angle, double)

computeNorthPointingTangentAtLocation

public Vec4 computeNorthPointingTangentAtLocation(Angle latitude,
                                                  Angle longitude)

Description copied from interface: Globe

Computes a vector tangent to this globe and pointing toward the north pole.

Specified by:

computeNorthPointingTangentAtLocation in interface Globe

Overrides:

computeNorthPointingTangentAtLocation in class EllipsoidalGlobe

Parameters:

latitude - Latitude of the location at which to compute the tangent vector.

longitude - Longitude of the location at which to compute the tangent vector.

Returns:

A vector tangent to this globe at (latitude, longitude), and pointing toward the north pole of this globe.

computeSurfaceNormalAtLocation

public Vec4 computeSurfaceNormalAtLocation(Angle latitude,
                                           Angle longitude)

Description copied from class: EllipsoidalGlobe

Returns the normal to the Globe at the specified position.

Specified by:

computeSurfaceNormalAtLocation in interface Globe

Overrides:

computeSurfaceNormalAtLocation in class EllipsoidalGlobe

Parameters:

latitude - the latitude of the position.

longitude - the longitude of the position.

Returns:

the Globe normal at the specified position.

computeSurfaceNormalAtPoint

public Vec4 computeSurfaceNormalAtPoint(Vec4 point)

Description copied from class: EllipsoidalGlobe

Returns the normal to the Globe at the specified cartiesian point.

Specified by:

computeSurfaceNormalAtPoint in interface Globe

Overrides:

computeSurfaceNormalAtPoint in class EllipsoidalGlobe

Parameters:

point - the cartesian point.

Returns:

the Globe normal at the specified point.

computeSurfaceOrientationAtPosition

public Matrix computeSurfaceOrientationAtPosition(Angle latitude,
                                                  Angle longitude,
                                                  double metersElevation)

Description copied from class: EllipsoidalGlobe

Returns the cartesian transform matrix that maps model coordinates to a local coordinate system at (latitude, longitude, metersElevation). The X axis is mapped to the vector tangent to the globe and pointing East. The Y axis is mapped to the vector tangent to the globe and pointing to the North Pole. The Z axis is mapped to the globe normal at (latitude, longitude, metersElevation). The origin is mapped to the cartesian position of (latitude, longitude, metersElevation).

Specified by:

computeSurfaceOrientationAtPosition in interface Globe

Overrides:

computeSurfaceOrientationAtPosition in class EllipsoidalGlobe

Parameters:

latitude - the latitude of the position.

longitude - the longitude of the position.

metersElevation - the number of meters above or below mean sea level.

Returns:

the cartesian transform matrix that maps model coordinates to the local coordinate system at the specified position.

geodeticToCartesian

protected Vec4 geodeticToCartesian(Angle latitude,
                                   Angle longitude,
                                   double metersElevation)

Maps a position to a flat world Cartesian coordinates. The world plane is located at the origin and has UNIT-Z as normal. The Y axis points to the north pole. The Z axis points up. The X axis completes a right-handed coordinate system, and points east. Latitude and longitude zero are at the origin on y and x respectively. Sea level is at z = zero.

Overrides:

geodeticToCartesian in class EllipsoidalGlobe

Parameters:

latitude - the latitude of the position.

longitude - the longitude of the position.

metersElevation - the number of meters above or below mean sea level.

Returns:

The Cartesian point corresponding to the input position.

geodeticToCartesian

protected void geodeticToCartesian(Sector sector,
                                   int numLat,
                                   int numLon,
                                   double[] metersElevation,
                                   Vec4[] out)

Description copied from class: EllipsoidalGlobe

Maps a grid of geographic positions to Cartesian coordinates. The Y axis points to the north pole. The Z axis points to the intersection of the prime meridian and the equator, in the equatorial plane. The X axis completes a right-handed coordinate system, and is 90 degrees east of the Z axis and also in the equatorial plane. Sea level is at z = zero.

This method provides an interface for efficient generation of a grid of cartesian points within a sector. The grid is constructed by dividing the sector into numLon x numLat evenly separated points in geographic coordinates. The first and last points in latitude and longitude are placed at the sector's minimum and maximum boundary, and the remaining points are spaced evenly between those boundary points.

For each grid point within the sector, an elevation value is specified via an array of elevations. The calculation at each position incorporates the associated elevation.

Overrides:

geodeticToCartesian in class EllipsoidalGlobe

Parameters:

sector - The sector over which to generate the points.

numLat - The number of points to generate latitudinally.

numLon - The number of points to generate longitudinally.

metersElevation - An array of elevations to incorporate in the point calculations. There must be one elevation value in the array for each generated point, so the array must have a length of at least numLon x numLat. Elevations are read from this array in row major order, beginning with the row of minimum latitude.

out - An array to hold the computed cartesian points. It must have a length of at least numLon x numLat. Points are written to this array in row major order, beginning with the row of minimum latitude.

getElevation

public double getElevation(Angle latitude,
                           Angle longitude)

Description copied from interface: Globe

Indicates the elevation at a specified location. If the elevation at the specified location is the elevation model's missing data signal, or if the location specified is outside the elevation model's coverage area, the elevation model's missing data replacement value is returned.

The elevation returned from this method is the best available in memory. If no elevation is in memory, the elevation model's minimum extreme elevation at the location is returned. Local disk caches are not consulted.

Specified by:

getElevation in interface Globe

Overrides:

getElevation in class EllipsoidalGlobe

Parameters:

latitude - the latitude of the location at which to determine elevation.

longitude - the longitude of the location at which to determine elevation.

Returns:

The elevation corresponding to the specified location, or the elevation model's missing-data replacement value if there is no elevation for the given location. Returns zero if no elevation model is available.

See Also:

Globe.getElevationModel()

getGlobeStateKey

public GlobeStateKey getGlobeStateKey()

Description copied from interface: Globe

Returns a typed state key identifying this globe's current configuration. Can be used to subsequently determine whether the globe's configuration has changed.

Specified by:

getGlobeStateKey in interface Globe

Overrides:

getGlobeStateKey in class EllipsoidalGlobe

Returns:

a state key for the globe's current configuration.

getGlobeStateKey

public GlobeStateKey getGlobeStateKey(DrawContext dc)

Description copied from interface: Globe

Returns a typed state key identifying this globe's current configuration. Can be used to subsequently determine whether the globe's configuration has changed.

Specified by:

getGlobeStateKey in interface Globe

Overrides:

getGlobeStateKey in class EllipsoidalGlobe

Parameters:

dc - the current draw context.

Returns:

a state key for the globe's current configuration.

getOffset

public int getOffset()

Specified by:

getOffset in interface Globe2D

getProjection

public GeographicProjection getProjection()

Indicates the projection used to project the globe onto a plane. The default projection is Mercator.

Specified by:

getProjection in interface Globe2D

Returns:

The active projection.

See Also:

setProjection(java.lang.String)

getStateKey

public java.lang.Object getStateKey(DrawContext dc)

Description copied from interface: Globe

Returns a state key identifying this globe's current configuration. Can be used to subsequently determine whether the globe's configuration has changed.

Specified by:

getStateKey in interface Globe

Overrides:

getStateKey in class EllipsoidalGlobe

Parameters:

dc - the current draw context.

Returns:

a state key for the globe's current configuration.

intersect

protected Intersection[] intersect(Line line,
                                   double equRadius,
                                   double polarRadius)

Overrides:

intersect in class EllipsoidalGlobe

intersects

public boolean intersects(Frustum frustum)

Description copied from interface: Extent

Determines whether or not this Extent intersects frustum. Returns true if any part of these two objects intersect, including the case where either object wholly contains the other, false otherwise.

Specified by:

intersects in interface Extent

Overrides:

intersects in class EllipsoidalGlobe

Parameters:

frustum - the Frustum with which to test for intersection.

Returns:

true if there is an intersection, false otherwise.

intersects

public boolean intersects(Line line)

Description copied from interface: Extent

Determines whether or not line intersects this Extent. This method may be faster than checking the size of the array returned by intersect(Line). Implementing methods must ensure that this method returns true if and only if intersect(Line) returns a non-null array containing at least one element.

Specified by:

intersects in interface Extent

Overrides:

intersects in class EllipsoidalGlobe

Parameters:

line - the Line with which to test for intersection.

Returns:

true if an intersection is found, false otherwise.

intersects

public boolean intersects(Plane plane)

Description copied from interface: Extent

Calculate whether or not this Extent is intersected by plane.

Specified by:

intersects in interface Extent

Overrides:

intersects in class EllipsoidalGlobe

Parameters:

plane - the Plane with which to test for intersection.

Returns:

true if plane is found to intersect this Extent.

isContinuous

public boolean isContinuous()

Description copied from interface: Globe2D

Indicates whether it makes sense to treat the associated projection as contiguous with itself. If true, the scene controller will make the implementing globe appear to scroll continuously horizontally.

Specified by:

isContinuous in interface Globe2D

Returns:

true if it makes sense to treat the associated projection as continuous, otherwise false.

isPointAboveElevation

public boolean isPointAboveElevation(Vec4 point,
                                     double elevation)

Determines whether a point is above a given elevation

Specified by:

isPointAboveElevation in interface Globe

Overrides:

isPointAboveElevation in class EllipsoidalGlobe

Parameters:

point - the Vec4 point to test.

elevation - the elevation to test for.

Returns:

true if the given point is above the given elevation.

setContinuous

public void setContinuous(boolean continuous)

Description copied from interface: Globe2D

Specifies whether to treat the associated projection as contiguous with itself. If true, the scene controller will make the implementing globe appear to scroll continuously horizontally. Calling this method overrides the associated projection's value for this field.

Specified by:

setContinuous in interface Globe2D

Parameters:

continuous - true if it makes sense to treat the associated projection as continuous, otherwise false.

See Also:

GeographicProjection.isContinuous()

setOffset

public void setOffset(int offset)

Description copied from interface: Globe2D

Indicates an offset to apply to Cartesian points computed by this globe. The offset is in units of globe widths, e.g., an offset of one indicates a Cartesian offset of the globe's width in meters.

Specified by:

setOffset in interface Globe2D

Parameters:

offset - The offset to apply, in units of globe widths.

setProjection

public void setProjection(GeographicProjection projection)

Description copied from interface: Globe2D

Specifies the geographic projection for this globe. The geographic projection converts geographic positions to Cartesian coordinates and back. Implementations of this interface define their default projection.

Specified by:

setProjection in interface Globe2D

Parameters:

projection - The projection to apply to this globe.

See Also:

GeographicProjection