com.bbn.openmap.proj
Class Gnomonic

java.lang.Object
  com.bbn.openmap.proj.Proj
      com.bbn.openmap.proj.GeoProj
          com.bbn.openmap.proj.Azimuth
              com.bbn.openmap.proj.Gnomonic

All Implemented Interfaces:

Projection, java.io.Serializable, java.lang.Cloneable

public class Gnomonic
extends Azimuth

Implements the Gnomonic projection.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.bbn.openmap.proj.Azimuth

Azimuth.AzimuthVar

Field Summary

protected double	cosCtrLat
static double	epsilon
static java.lang.String	GnomonicName The Gnomonic name.
static double	HEMISPHERE_EDGE
static double	hPrime
protected double	hy
protected static float	NORTH_BOUNDARY
protected double	sinCtrLat
protected static float	SOUTH_BOUNDARY
protected double	wx

Fields inherited from class com.bbn.openmap.proj.Azimuth

clockwise, spaceColor, world

Fields inherited from class com.bbn.openmap.proj.GeoProj

DATELINE, mercator, NORTH_POLE, NUM_DEFAULT_CIRCLE_VERTS, NUM_DEFAULT_GREAT_SEGS, pixelsPerMeter, planetPixelCircumference, planetPixelRadius, planetRadius, scaled_radius, SOUTH_POLE, XSCALE_THRESHOLD, XTHRESHOLD

Fields inherited from class com.bbn.openmap.proj.Proj

centerX, centerY, height, maxscale, MIN_HEIGHT, MIN_WIDTH, minscale, projID, rotationAngle, scale, ucuom, width

Constructor Summary

Gnomonic(LatLonPoint center, float scale, int width, int height)
Construct a Mercator projection.

Method Summary

protected java.awt.geom.Point2D	_forward(double phi, double lambda, java.awt.geom.Point2D p, Azimuth.AzimuthVar azVar) Forward project a point.
protected java.awt.geom.Point2D	_forward(float phi, float lambda, java.awt.geom.Point2D p, Azimuth.AzimuthVar azVar) Forward project a point.
protected void	computeParameters() Called when some fundamental parameters change.
void	drawBackground(java.awt.Graphics g) Assume that the Graphics has been set with the Paint/Color needed, just render the shape of the background.
LatLonPoint	getLowerRight() Get the lower right (southeast) point of the projection.
java.lang.String	getName() Get the name string of the projection.
LatLonPoint	getUpperLeft() Get the upper left (northernmost and westernmost) point of the projection.
static boolean	hemisphere_clip(double phi1, double lambda0, double phi, double lambda)
static boolean	hemisphere_clip(float phi1, float lambda0, float phi, float lambda) Check if a given lat/lon is within the visible hemisphere.
static double	hemisphere_distance(double phi1, double lambda0, double phi, double lambda)
protected void	init() Called after the center and scale is set in setParams, but before the scale is checked for legitimacy.
<T extends java.awt.geom.Point2D> T	inverse(double x, double y, T llp) Inverse project x,y coordinates into a LatLonPoint.
boolean	isPlotable(double lat, double lon) Checks if a LatLonPoint is plot-able.
double	normalizeLatitude(double lat) Sets radian latitude to something sane.
boolean	overEquator() Check if equator is visible on screen.
java.lang.String	toString() Return stringified description of this projection.

Methods inherited from class com.bbn.openmap.proj.Azimuth

_forwardPoly, _forwardPoly, _panE, _panN, _panNE, _panNW, _panS, _panSE, _panSW, _panW, forward, forwardRaw, forwardRaw, getSpaceColor, isClockwiseTraversal, overNorthPole, overPoint, overSouthPole, pan, setClockwiseTraversal, setSpaceColor

Methods inherited from class com.bbn.openmap.proj.GeoProj

assertLatLonPoint, clone, doPolyDispatch, doPolyDispatch, forward, forward, forward, forward, forwardArc, forwardArc, forwardArc, forwardCircle, forwardCircle, forwardCircle, forwardGreatPoly, forwardGreatPoly, forwardLine, forwardLine, forwardLLPoly, forwardPoly, forwardPoly, forwardRect, forwardRect, forwardRect, forwardRhumbPoly, forwardRhumbPoly, getCenter, getCenter, getGCTForProjection, getPlanetPixelCircumference, getPlanetPixelRadius, getPlanetRadius, getPPM, getReferenceLon, getScale, getUcuom, inverse, inverse, isComplicatedLineType, isPlotable, normalize_latitude, normalizeLatitude, pan, pan, setCenter, setCenter, setCenter, setPlanetRadius, setPPM, setUcuom, wrap_longitude, wrapLongitude, wrapLongitude, wrapLongitudeDeg

Methods inherited from class com.bbn.openmap.proj.Proj

drawBackground, equals, forward, forward, forward, forwardLine, forwardPoly, forwardPoly, forwardRect, forwardShape, getHeight, getMaxScale, getMinScale, getProjectionID, getRotationAngle, getScale, getWidth, hashCode, inverse, inverseShape, makeClone, panE, panE, panN, panN, panNE, panNE, panNW, panNW, panS, panS, panSE, panSE, panSW, panSW, panW, panW, setCenter, setHeight, setMaxScale, setMinScale, setParms, setProjectionID, setRotationAngle, setScale, setWidth

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

GnomonicName

public static final transient java.lang.String GnomonicName

The Gnomonic name.

See Also:

Constant Field Values

hy

protected double hy

wx

protected double wx

cosCtrLat

protected double cosCtrLat

sinCtrLat

protected double sinCtrLat

epsilon

public static final transient double epsilon

See Also:

Constant Field Values

HEMISPHERE_EDGE

public static final transient double HEMISPHERE_EDGE

See Also:

Constant Field Values

hPrime

public static final transient double hPrime

NORTH_BOUNDARY

protected static final float NORTH_BOUNDARY

See Also:

Constant Field Values

SOUTH_BOUNDARY

protected static final float SOUTH_BOUNDARY

See Also:

Constant Field Values

Constructor Detail

Gnomonic

public Gnomonic(LatLonPoint center,
                float scale,
                int width,
                int height)

Construct a Mercator projection.

Parameters:

center - LatLonPoint center of projection

scale - float scale of projection

width - width of screen

height - height of screen

Method Detail

toString

public java.lang.String toString()

Return stringified description of this projection.

Overrides:

toString in class Azimuth

Returns:

String

See Also:

Projection.getProjectionID()

init

protected void init()

Description copied from class: Proj

Called after the center and scale is set in setParams, but before the scale is checked for legitimacy. This is an opportunity to set constants in subclasses before anything else gets called or checked for validity. This is different than computeParameters() which is called after some checks. This is a good time to pre-calculate constants and set maxscale and minscale.

Make sure you call super.init() if you override this method.

Overrides:

init in class Azimuth

computeParameters

protected void computeParameters()

Called when some fundamental parameters change.

Each projection will decide how to respond to this change. For instance, they may need to recalculate "constant" parameters used in the forward() and inverse() calls.

Overrides:

computeParameters in class Azimuth

drawBackground

public void drawBackground(java.awt.Graphics g)

Assume that the Graphics has been set with the Paint/Color needed, just render the shape of the background.

Overrides:

drawBackground in class Azimuth

Parameters:

g - Graphics

normalizeLatitude

public double normalizeLatitude(double lat)

Sets radian latitude to something sane. This is an abstract function since some projections don't deal well with extreme latitudes.

Specified by:

normalizeLatitude in class GeoProj

Parameters:

lat - float latitude in radians

Returns:

float latitude (-PI/2 <= y <= PI/2)

hemisphere_distance

public static final double hemisphere_distance(double phi1,
                                               double lambda0,
                                               double phi,
                                               double lambda)

hemisphere_clip

public static final boolean hemisphere_clip(float phi1,
                                            float lambda0,
                                            float phi,
                                            float lambda)

Check if a given lat/lon is within the visible hemisphere.

Parameters:

phi1 - latitude

lambda0 - longitude

phi - latitude

lambda - longitude

Returns:

boolean true if within the visible hemisphere, false if not

hemisphere_clip

public static final boolean hemisphere_clip(double phi1,
                                            double lambda0,
                                            double phi,
                                            double lambda)

isPlotable

public boolean isPlotable(double lat,
                          double lon)

Checks if a LatLonPoint is plot-able.

A point is plot-able if it is within the visible hemisphere.

Specified by:

isPlotable in interface Projection

Overrides:

isPlotable in class Proj

Parameters:

lat - float latitude in decimal degrees

lon - float longitude in decimal degrees

Returns:

boolean

_forward

protected java.awt.geom.Point2D _forward(float phi,
                                         float lambda,
                                         java.awt.geom.Point2D p,
                                         Azimuth.AzimuthVar azVar)

Forward project a point. If the point is not within the viewable hemisphere, return flags in AzimuthVar variable if specified.

Parameters:

phi - float latitude in radians

lambda - float longitude in radians

p - Point2D

azVar - AzimuthVar or null

Returns:

Point2D pt

_forward

protected java.awt.geom.Point2D _forward(double phi,
                                         double lambda,
                                         java.awt.geom.Point2D p,
                                         Azimuth.AzimuthVar azVar)

Forward project a point. If the point is not within the viewable hemisphere, return flags in AzimuthVar variable if specified.

Specified by:

_forward in class Azimuth

Parameters:

phi - double latitude in radians

lambda - double longitude in radians

p - Point2D

azVar - AzimuthVar or null

Returns:

Point2D pt

inverse

public <T extends java.awt.geom.Point2D> T inverse(double x,
                                                   double y,
                                                   T llp)

Inverse project x,y coordinates into a LatLonPoint.

Specified by:

inverse in interface Projection

Specified by:

inverse in class Proj

Parameters:

x - integer x coordinate

y - integer y coordinate

llp - LatLonPoint

Returns:

LatLonPoint llp

See Also:

Proj.inverse(Point2D)

overEquator

public boolean overEquator()

Check if equator is visible on screen.

Returns:

boolean

getUpperLeft

public LatLonPoint getUpperLeft()

Get the upper left (northernmost and westernmost) point of the projection.

Returns the upper left point (or closest equivalent) of the projection based on the center point and height and width of screen.

Specified by:

getUpperLeft in interface Projection

Overrides:

getUpperLeft in class Proj

Returns:

LatLonPoint

getLowerRight

public LatLonPoint getLowerRight()

Get the lower right (southeast) point of the projection.

Returns the lower right point (or closest equivalent) of the projection based on the center point and height and width of screen.

This is trivial for most cylindrical projections, but much more complicated for azimuthal projections.

Specified by:

getLowerRight in interface Projection

Overrides:

getLowerRight in class Proj

Returns:

LatLonPoint

getName

public java.lang.String getName()

Get the name string of the projection.

Specified by:

getName in interface Projection

Overrides:

getName in class Azimuth