Package com.luciad.projection
Class TLcdGeneralPerspective
java.lang.Object
com.luciad.projection.ALcdProjection
com.luciad.projection.ALcdGeneralPerspective
com.luciad.projection.TLcdGeneralPerspective
 All Implemented Interfaces:
ILcdGeneralPerspective
,ILcdProjection
,ILcdPropertyChangeSource
,Serializable
,Cloneable
General perspective projection.
Introduction
The general perspective projection is an azimuthal projection using the origin of projection and the point of perspective. The origin height is taken into account. It is possible to tilt the projection plane.
Properties
 The central meridian and a particular parallel (if shown) are projected as straight lines.
 Other meridians and parallels are usually arcs of circles or ellipses, but some may be parabolas or hyperbolas.
 Neither conformal (unless Stereographic), nor equalarea.
 If the point of perspective is above the center of the sphere or ellipsoid, les than one hemisphere may be shown (unless Orthographic).
 If the point of perspective is below the center of the globe, more than one hemisphere may be shown (cfr. Stereographic).
 There is considarable distortion near the projection limit.
Example
Sample code
ILcdProjection projection =
new TLcdGeneralPerspective(40.0, 100.0, 0.0, 2.0, 0.0, 0.0);
Implementation aspects
The equations of the general perspective projection are taken from [Snyder1987].
Note
The point of perspective has to be outside the earth ellipsoid. So, its value should be outside the closed interval [1.0,1.0].
 See Also:

Field Summary
Fields inherited from class com.luciad.projection.ALcdProjection
fPropertyChangeDispatcher
Fields inherited from interface com.luciad.projection.ILcdProjection
EPSILON

Constructor Summary
ConstructorDescriptionConstructs a general perspective projection with the origin at point(0.0, 0.0, 0.0)
, the perspective distance at 2.0, the azimuth set to 0.0, and the tilt set to 0.0.TLcdGeneralPerspective
(double aLongitude, double aLatitude, double aHeight, double aPerspectiveDistance, double aAzimuth, double aTiltAngle) Constructs a general perspective projection with the origin at a point(aLatitude, aLongitude, aHeight)
.TLcdGeneralPerspective
(ILcdPoint aOrigin, double aPerspectiveDistance) Constructs a general perspective projection with the origin at anILcdPoint
aOrigin
and a point of perspective at a distance (divided by the semimajor axis) from the center of the earth.TLcdGeneralPerspective
(ILcdPoint aOrigin, double aPerspectiveDistance, double aAzimuth, double aTiltAngle) Constructs a general perspective projection with the origin at anILcdPoint
aOrigin
and a point of perspective at a distance (divided by the semimajor axis) from the center of the earth. 
Method Summary
Modifier and TypeMethodDescriptiondouble[][]
boundaryLats
(double lon) Default implementation.double[][]
boundaryLons
(double lat) Default implementation.protected void
Constants based on the longitude, latitude, height of the point of origin of projection and the distance of the point of perspective don't have to be recalculated every time a method is called.clone()
Makes a deep clone of thisILcdProjection
.boolean
inLonLatBounds
(ILcdPoint aLLP) Checks if anILcdPoint
is inside the valid area of geodetic coordinates of the projection.boolean
inWorldBoundsOnSphere
(ILcdPoint aXYPoint, double aRadius) Checks if aILcdPoint
is inside the valid cartesian area of the projection.boolean
If all geodetic coordinates (l ,j ) are projected (visible) by anILcdProjection
and all (x,y ) coordinates are bounded this istrue
.void
lonlatheight2worldOnEllipsoidSFCT
(ILcdPoint aLLHP, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aWorldPoint) Default implementation callslonlatheight2worldOnEllipsoidSFCT
withaEllipsoid.getAuxRadius()
as sphere radius.void
lonlatheight2worldOnSphereSFCT
(ILcdPoint aLLHP, double aRadius, ILcd2DEditablePoint aWorldPoint) Transforms anILcd2DEditablePoint
on a sphere into the cartesian coordinate system of the projection.toString()
Returns theString
representation of the general perspective projection.void
world2DEditableBoundsOnSphereSFCT
(double aRadius, ILcd2DEditableBounds aWorldBound) The projection is bounded when the perspective distance is outside the closed interval [1,1].void
world2lonlatOnEllipsoidSFCT
(ILcdPoint aXYPoint, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aLLPSFCT) Transforms a world point to a LonLatHeightPoint.void
world2lonlatOnSphereSFCT
(ILcdPoint aXYPoint, double aRadius, ILcd2DEditablePoint aLLPSFCT) Transforms anILcdPoint
from the cartesian coordinate system of the projection into anILcd2DEditablePoint
onto a sphere.Methods inherited from class com.luciad.projection.ALcdGeneralPerspective
equals, getAzimuth, getOrigin, getOriginHeight, getOriginLat, getOriginLon, getPerspectiveDistance, getTilt, hashCode, isContinuous, loadProperties, setAzimuth, setOriginHeight, setOriginLat, setOriginLon, setPerspectiveDistance, setTilt, writePropertiesSFCT
Methods inherited from class com.luciad.projection.ALcdProjection
addPropertyChangeListener, firePropertyChangeEvent, inWorldBoundsOnEllipsoid, removePropertyChangeListener, world2DEditableBoundsOnEllipsoidSFCT
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface com.luciad.projection.ILcdProjection
inWorldBoundsOnEllipsoid, world2DEditableBoundsOnEllipsoidSFCT
Methods inherited from interface com.luciad.util.ILcdPropertyChangeSource
addPropertyChangeListener, removePropertyChangeListener

Constructor Details

TLcdGeneralPerspective
public TLcdGeneralPerspective()Constructs a general perspective projection with the origin at point(0.0, 0.0, 0.0)
, the perspective distance at 2.0, the azimuth set to 0.0, and the tilt set to 0.0. 
TLcdGeneralPerspective
public TLcdGeneralPerspective(double aLongitude, double aLatitude, double aHeight, double aPerspectiveDistance, double aAzimuth, double aTiltAngle) Constructs a general perspective projection with the origin at a point(aLatitude, aLongitude, aHeight)
. Parameters:
aLongitude
 longitude of the origin of the projection, in decimal degrees.aLatitude
 latitude of the origin of the projection, in decimal degrees.aHeight
 height of the origin point above the ellipsoid.aPerspectiveDistance
 distance of the point of perspective from the center of the earth globe divided by the semimajor axis.aAzimuth
 azimuth east of north of the Yaxis of the Y_t axis of the tilted plane of projectionaTiltAngle
 upward angle of tilt, or the angle between the Y_t axis and the tangent plane, expressed in degrees

TLcdGeneralPerspective
Constructs a general perspective projection with the origin at anILcdPoint
aOrigin
and a point of perspective at a distance (divided by the semimajor axis) from the center of the earth. The properties azimuth and tiltAngle are set to zero. Parameters:
aOrigin
 point of origin (3D) of the projection.aPerspectiveDistance
 distance of the point of perspective from the center of the earth globe divided by the semimajor axis.

TLcdGeneralPerspective
public TLcdGeneralPerspective(ILcdPoint aOrigin, double aPerspectiveDistance, double aAzimuth, double aTiltAngle) Constructs a general perspective projection with the origin at anILcdPoint
aOrigin
and a point of perspective at a distance (divided by the semimajor axis) from the center of the earth. Parameters:
aOrigin
 point of origin (3D) of the projection.aPerspectiveDistance
 distance of the point of perspective from the center of the earth globe divided by the semimajor axis.aAzimuth
 azimuth east of north of the Yaxis of the Y_t axis of the tilted plane of projectionaTiltAngle
 upward angle of tilt, or the angle between the Y_t axis and the tangent plane, expressed in degrees


Method Details

calculateCachedValues
protected void calculateCachedValues()Description copied from class:ALcdGeneralPerspective
Constants based on the longitude, latitude, height of the point of origin of projection and the distance of the point of perspective don't have to be recalculated every time a method is called. They only have to be calculated when the projection properties change. Within the methods the precalculated values then can be used in order to gain efficiency. Overrides:
calculateCachedValues
in classALcdGeneralPerspective

isAllInBounds
public boolean isAllInBounds()Description copied from interface:ILcdProjection
If all geodetic coordinates (l ,j ) are projected (visible) by anILcdProjection
and all (x,y ) coordinates are bounded this istrue
. AllILcdProjection
objects have bounded (x,y ) coordinates because the projection is cut off if necessary. Returns:
true
if all LonLatPoints are within the bounds of the projection,false
otherwise.

lonlatheight2worldOnSphereSFCT
public void lonlatheight2worldOnSphereSFCT(ILcdPoint aLLHP, double aRadius, ILcd2DEditablePoint aWorldPoint) throws TLcdOutOfBoundsException Description copied from interface:ILcdProjection
Transforms anILcd2DEditablePoint
on a sphere into the cartesian coordinate system of the projection. Parameters:
aLLHP
 point to be projected.aRadius
 radius of the sphere (meters).aWorldPoint
 projected point as side effect. Throws:
TLcdOutOfBoundsException
 If theILcdPoint
aLLHP
is not within the valid area of the projection (visible area), then this exception is thrown.

lonlatheight2worldOnEllipsoidSFCT
public void lonlatheight2worldOnEllipsoidSFCT(ILcdPoint aLLHP, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aWorldPoint) throws TLcdOutOfBoundsException Description copied from class:ALcdProjection
Default implementation callslonlatheight2worldOnEllipsoidSFCT
withaEllipsoid.getAuxRadius()
as sphere radius. Specified by:
lonlatheight2worldOnEllipsoidSFCT
in interfaceILcdProjection
 Overrides:
lonlatheight2worldOnEllipsoidSFCT
in classALcdProjection
 Parameters:
aLLHP
 point to be projected.aEllipsoid
 ellipsoid on which the point is defined.aWorldPoint
 projected point as side effect. Throws:
TLcdOutOfBoundsException
 If theILcdPoint
aLLHP
is not within the valid area of the projection (visible area), then this exception is thrown.

world2lonlatOnSphereSFCT
public void world2lonlatOnSphereSFCT(ILcdPoint aXYPoint, double aRadius, ILcd2DEditablePoint aLLPSFCT) throws TLcdOutOfBoundsException Description copied from interface:ILcdProjection
Transforms anILcdPoint
from the cartesian coordinate system of the projection into anILcd2DEditablePoint
onto a sphere. Parameters:
aXYPoint
 projected point for which the corresponding geodetic point is sought.aRadius
 radius of the sphere (meters).aLLPSFCT
 resulting geodetic coordinate as side effect. Throws:
TLcdOutOfBoundsException
 If theILcdPoint
aXYPoint
is not within the valid area of the projection (visible area), then this exception is thrown.

world2lonlatOnEllipsoidSFCT
public void world2lonlatOnEllipsoidSFCT(ILcdPoint aXYPoint, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aLLPSFCT) throws TLcdOutOfBoundsException Transforms a world point to a LonLatHeightPoint. The height, which is taken into account, is supposed to be available in the input/output parameteraLLPSFCT
. Specified by:
world2lonlatOnEllipsoidSFCT
in interfaceILcdProjection
 Overrides:
world2lonlatOnEllipsoidSFCT
in classALcdProjection
 Parameters:
aXYPoint
 projected point for which the corresponding geodetic point is sought.aEllipsoid
 ellipsoid on which the geodetic coordinate is defined.aLLPSFCT
 resulting geodetic coordinate as side effect. Throws:
TLcdOutOfBoundsException
 If theILcdPoint
aXYPoint
is not within the valid area of the projection (visible area), then this exception is thrown.

inLonLatBounds
Description copied from interface:ILcdProjection
Checks if anILcdPoint
is inside the valid area of geodetic coordinates of the projection. The valid area is determined by the LonLatPoints that are visible and for which the corresponding cartesian coordinate is within the boundaries. Parameters:
aLLP
ILcdPoint
to be checked upon. Returns:
true
if valid,false
if invalid.

boundaryLons
public double[][] boundaryLons(double lat) Description copied from class:ALcdProjection
Default implementation. To be redefined for specific projections. Specified by:
boundaryLons
in interfaceILcdProjection
 Overrides:
boundaryLons
in classALcdProjection
 Parameters:
lat
 latitude in decimal degrees and 90.0 <=aLat
<= 90.0. Returns:
 the array of pairs of longitudes[0] and longitudes[1], where the closed interval longitudes[0] > longitudes[1] is in visible area and 180.0 <= lon[i] <= 180.0.

boundaryLats
public double[][] boundaryLats(double lon) Description copied from class:ALcdProjection
Default implementation. To be redefined for specific projections. Specified by:
boundaryLats
in interfaceILcdProjection
 Overrides:
boundaryLats
in classALcdProjection
 Parameters:
lon
 longitude in decimal degrees 180.0 <= lon <= 180.0 . Returns:
 the array of pairs of latitudes lats[0] and lats[1], where the closed interval lats[0] > lats[1] is in visible area and 90.0 <= lats[i] <= 90.0 .

world2DEditableBoundsOnSphereSFCT
The projection is bounded when the perspective distance is outside the closed interval [1,1]. Currently a perspective distance within this closed interval [1,1] is not supported. Parameters:
aRadius
 radius of the sphere.aWorldBound
 the bounds of the projection in world coordinates as side effect.

inWorldBoundsOnSphere
Description copied from interface:ILcdProjection
Checks if aILcdPoint
is inside the valid cartesian area of the projection. The valid cartesian area is determined naturally by the projection bounds or by an artificial introduced boundary limit because some cartesian points are at infinity. The shape of the valid cartesian area is in many cases rectangular or circular although it might be more complex. Parameters:
aXYPoint
 point to be checked upon.aRadius
 radius of the sphere. Returns:
true
if valid,false
if invalid.

toString
Returns theString
representation of the general perspective projection. Specified by:
toString
in interfaceILcdProjection
 Overrides:
toString
in classObject
 Returns:
 the
String
representation of the general perspective projection.

clone
Description copied from interface:ILcdProjection
Makes a deep clone of thisILcdProjection
. Specified by:
clone
in interfaceILcdProjection
 Overrides:
clone
in classALcdGeneralPerspective
 Returns:
 deep clone of this
ILcdProjection
.
