com.bbn.openmap.proj
Class LambertConformal

java.lang.Object
  com.bbn.openmap.proj.Proj
      com.bbn.openmap.proj.GeoProj
          com.bbn.openmap.proj.LambertConformal

All Implemented Interfaces:

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

public class LambertConformal
extends GeoProj

Implements the LambertConformalConic projection.

NOTE: This implementation only works for the northern hemisphere.

Needs to be modified for use in the southern hemisphere.

See http://www.epsg.org/guides/docs/G7-2.pdf

Author:

David J. Ward, Chris van Lith

See Also:

Serialized Form

Field Summary

static double	EPS10 A small number 10^(-10) This number can be re-factored into MoreMath
static java.lang.String	LambertConformalName The LambertCC name.
protected java.awt.geom.Point2D	plotablePoint

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

protected	LambertConformal(LatLonPoint center, float scale, int width, int height) Construct a Lambert projection.
	LambertConformal(LatLonPoint center, float scale, int width, int height, double centralMeridian, double sp_one, double sp_two, double reference_latitude, double falseEasting, double falseNorthing, Ellipsoid ellps) Constructor for the lambert conformal projection.
protected	LambertConformal(LatLonPoint center, float scale, int width, int height, float centralMeridian, float sp_one, float sp_two, Ellipsoid ellps) Constructor for the lambert conformal projection.

Method Summary

protected double	_forward(double lat, double lon, java.awt.geom.Point2D p, boolean isRadian)
java.util.ArrayList<float[]>	_forwardPoly(double[] rawllpts, int ltype, int nsegs, boolean isFilled) Forward project a lat/lon Poly.
protected java.util.ArrayList<float[]>	_forwardPoly(float[] rawllpts, int ltype, int nsegs, boolean isFilled) Forward project a lat/lon Poly.
void	computeParameters() Called when some fundamental parameters change.
void	drawBackground(java.awt.Graphics g) Draw the background for the projection.
void	drawBackground(java.awt.Graphics2D g, java.awt.Paint paint) Draw the background for the projection.
java.awt.geom.Point2D	forward(double lat, double lon, java.awt.geom.Point2D p, boolean isRadian) Forward projects lat,lon into XY space and sets the results in the p provided.
boolean	forwardRaw(double[] rawllpts, int rawoff, float[] xcoords, float[] ycoords, boolean[] visible, int copyoff, int copylen) Forward project a raw array of points.
boolean	forwardRaw(float[] rawllpts, int rawoff, float[] xcoords, float[] ycoords, boolean[] visible, int copyoff, int copylen) Forward project a raw array of radian points.
LatLonPoint	getLowerRight() Get the lower right (southeast) point of the projection.
java.lang.String	getName() Get the name string of the projection.
double	getReferenceLon()
float	getScale(java.awt.geom.Point2D ll1, java.awt.geom.Point2D ll2, java.awt.geom.Point2D point1, java.awt.geom.Point2D point2) Given a couple of points representing a bounding box, find out what the scale should be in order to make those points appear at the corners of the projection.
LatLonPoint	getUpperLeft() Get the upper left (northwest) point of the projection.
<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) Determine if the location is plotable on the screen.
boolean	isPlotable(LatLonPoint llpoint) Determine if the location is plotable
static double	lambMsfn(double sinphi, double cosphi, double e) Special function m = cos(phi) / sqrt(1.0 - (e*sin(phi))**2)
static double	lambTsfn(double phi, double sinphi, double e) Special function t = tan(PI/4-phi/2) / pow((1-sinphi)/(1+sinphi), .5*e)
double	LLToPixel(double lat, double lon, java.awt.geom.Point2D p)
java.awt.geom.Point2D	LLToWorld(double lat, double lon, java.awt.geom.Point2D lp)
protected double	LLToWorldReturningLon(double lat, double lon, java.awt.geom.Point2D lp) LLToWorld that returns normalized longitude in radians, to be used for more calculations in some methods.
static void	main(java.lang.String[] argv) test method
double	normalizeLatitude(double lat) Sets radian latitude to something sane.
java.awt.geom.Point2D	pixelToLL(double xabs, double yabs, java.awt.geom.Point2D llp)
java.awt.geom.Point2D	pixelToWorld(java.awt.Point p, java.awt.geom.Point2D lp)
java.awt.geom.Point2D	worldToLL(double x, double y, java.awt.geom.Point2D llp)
java.awt.Point	worldToPixel(java.awt.geom.Point2D lp, java.awt.Point p)

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, getUcuom, init, inverse, inverse, isComplicatedLineType, isPlotable, normalize_latitude, normalizeLatitude, pan, pan, setCenter, setCenter, setCenter, setPlanetRadius, setPPM, setUcuom, toString, wrap_longitude, wrapLongitude, wrapLongitude, wrapLongitudeDeg

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

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

LambertConformalName

public static final transient java.lang.String LambertConformalName

The LambertCC name.

See Also:

Constant Field Values

EPS10

public static final double EPS10

A small number 10^(-10) This number can be re-factored into MoreMath

See Also:

Constant Field Values

plotablePoint

protected java.awt.geom.Point2D plotablePoint

Constructor Detail

LambertConformal

protected LambertConformal(LatLonPoint center,
                           float scale,
                           int width,
                           int height)

Construct a Lambert projection.

Parameters:

center - LatLonPoint center of projection

scale - float scale of projection

width - width of screen

height - height of screen

LambertConformal

protected LambertConformal(LatLonPoint center,
                           float scale,
                           int width,
                           int height,
                           float centralMeridian,
                           float sp_one,
                           float sp_two,
                           Ellipsoid ellps)

Constructor for the lambert conformal projection.

Parameters:

center - center location for projections

scale - scale of projection

width - width of projection

height - height of projection

centralMeridian - the Central Meridian in degrees.

sp_one - Standard Parallel One in degrees.

sp_two - Standard Parallel Two in degrees.

LambertConformal

public LambertConformal(LatLonPoint center,
                        float scale,
                        int width,
                        int height,
                        double centralMeridian,
                        double sp_one,
                        double sp_two,
                        double reference_latitude,
                        double falseEasting,
                        double falseNorthing,
                        Ellipsoid ellps)

Constructor for the lambert conformal projection.

Parameters:

center - center location for projections

scale - scale of projection

width - width of projection

height - height of projection

centralMeridian - the Central Meridian in degrees.

sp_one - Standard Parallel One in degrees.

sp_two - Standard Parallel Two in degrees.

reference_latitude - the latitude for the origin of the projection

falseEasting - number of meters added as buffer to origin E/W.

falseNorthing - number of meters added as buffer to origin for N/S.

ellps - the Ellipsoid used for the projection

Method Detail

computeParameters

public 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.

Specified by:

computeParameters in class Proj

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)

LLToWorld

public java.awt.geom.Point2D LLToWorld(double lat,
                                       double lon,
                                       java.awt.geom.Point2D lp)

LLToWorldReturningLon

protected double LLToWorldReturningLon(double lat,
                                       double lon,
                                       java.awt.geom.Point2D lp)

LLToWorld that returns normalized longitude in radians, to be used for more calculations in some methods. Do not provide a NULL lp here if you want the world coordinates provided back to you.

Parameters:

lat - latitude in degrees

lon - longitude in degrees.

lp - world coordinates are provided back in this object, make sure it's not null if you care about them.

Returns:

normalized longitude in radians, radians lon - radians lat.

LLToPixel

public double LLToPixel(double lat,
                        double lon,
                        java.awt.geom.Point2D p)

worldToPixel

public java.awt.Point worldToPixel(java.awt.geom.Point2D lp,
                                   java.awt.Point p)

pixelToWorld

public java.awt.geom.Point2D pixelToWorld(java.awt.Point p,
                                          java.awt.geom.Point2D lp)

worldToLL

public java.awt.geom.Point2D worldToLL(double x,
                                       double y,
                                       java.awt.geom.Point2D llp)

pixelToLL

public java.awt.geom.Point2D pixelToLL(double xabs,
                                       double yabs,
                                       java.awt.geom.Point2D llp)

isPlotable

public boolean isPlotable(double lat,
                          double lon)

Determine if the location is plotable on the screen. The Lambert Conformal projection does not lend its self to a simple determination. This method invokes forward to obtain the screen coordinates. If the screen coordinates are visible returns true otherwise returns false.

Specified by:

isPlotable in interface Projection

Overrides:

isPlotable in class Proj

Parameters:

lat - latitude in degrees

lon - longitude in degrees

Returns:

true is plotable, otherwise false

isPlotable

public boolean isPlotable(LatLonPoint llpoint)

Determine if the location is plotable

Parameters:

llpoint - location to check

Returns:

returns true is plotable, otherwise false

forward

public java.awt.geom.Point2D forward(double lat,
                                     double lon,
                                     java.awt.geom.Point2D p,
                                     boolean isRadian)

Forward projects lat,lon into XY space and sets the results in the p provided.

Specified by:

forward in class GeoProj

Parameters:

lat - latitude

lon - longitude

p - Resulting XY Point2D

isRadian - indicates that lat,lon arguments are in radians

Returns:

Point2D p

_forward

protected double _forward(double lat,
                          double lon,
                          java.awt.geom.Point2D p,
                          boolean isRadian)

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)

getUpperLeft

public LatLonPoint getUpperLeft()

Get the upper left (northwest) 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.

Specified by:

getLowerRight in interface Projection

Overrides:

getLowerRight in class Proj

Returns:

LatLonPoint

getReferenceLon

public double getReferenceLon()

Overrides:

getReferenceLon in class GeoProj

Returns:

the reference longitude of the projection. For most projections, it'll just be the center point longitude. For LLC, it'll be the reference meridian.

getName

public java.lang.String getName()

Get the name string of the projection.

Specified by:

getName in interface Projection

Overrides:

getName in class Proj

Returns:

the projection name

forwardRaw

public boolean forwardRaw(float[] rawllpts,
                          int rawoff,
                          float[] xcoords,
                          float[] ycoords,
                          boolean[] visible,
                          int copyoff,
                          int copylen)

Forward project a raw array of radian points. This assumes nothing about the array of coordinates. In no way does it assume the points are connected or that the composite figure is to be filled.

It does populate a visible array indicating whether the points are visible on the projected view of the world.

Specified by:

forwardRaw in interface Projection

Overrides:

forwardRaw in class Proj

Parameters:

rawllpts - array of lat,lon,... in radians

rawoff - offset into rawllpts

xcoords - x coordinates

ycoords - y coordinates

visible - coordinates visible?

copyoff - offset into x,y,visible arrays

copylen - number of coordinates (coordinate arrays should be at least this long, rawllpts should be at least twice as long).

Returns:

boolean true if all points visible, false if some points not visible.

forwardRaw

public boolean forwardRaw(double[] rawllpts,
                          int rawoff,
                          float[] xcoords,
                          float[] ycoords,
                          boolean[] visible,
                          int copyoff,
                          int copylen)

Description copied from class: Proj

Forward project a raw array of points. This assumes nothing about the array of coordinates. In no way does it assume the points are connected or that the composite figure is to be filled.

It does populate a visible array indicating whether the points are visible on the projected view of the world.

Specified by:

forwardRaw in interface Projection

Overrides:

forwardRaw in class Proj

Parameters:

rawllpts - array of y, x world coordinates.

rawoff - offset into rawllpts.

xcoords - x projected horizontal map coordinates.

ycoords - y projected vertical map coordinates.

visible - coordinates visible?

copyoff - offset into x,y visible arrays.

copylen - number of coordinates (coordinate arrays should be at least this long, rawllpts should be at least twice as long).

Returns:

boolean true if all points visible, false if some points not visible.

_forwardPoly

protected java.util.ArrayList<float[]> _forwardPoly(float[] rawllpts,
                                                    int ltype,
                                                    int nsegs,
                                                    boolean isFilled)

Forward project a lat/lon Poly. Remember to specify vertices in radians!

Specified by:

_forwardPoly in class GeoProj

Parameters:

rawllpts - float[] of lat,lon,lat,lon,... in RADIANS!

ltype - line type (straight, rhumbline, greatcircle)

nsegs - number of segment points (only for greatcircle or rhumbline line types, and if < 1, this value is generated internally)

isFilled - filled poly? this is currently ignored for cylindrical projections.

Returns:

ArrayList float[] of x[], y[], x[], y[], ... projected poly

_forwardPoly

public java.util.ArrayList<float[]> _forwardPoly(double[] rawllpts,
                                                 int ltype,
                                                 int nsegs,
                                                 boolean isFilled)

Description copied from class: GeoProj

Forward project a lat/lon Poly. Remember to specify vertices in radians!

Specified by:

_forwardPoly in class GeoProj

Parameters:

rawllpts - double[] of lat,lon,lat,lon,... in RADIANS!

ltype - line type (straight, rhumbline, greatcircle)

nsegs - number of segment points (only for greatcircle or rhumbline line types, and if < 1, this value is generated internally)

isFilled - filled poly?

Returns:

ArrayList of x[], y[], x[], y[], ... projected poly

getScale

public float getScale(java.awt.geom.Point2D ll1,
                      java.awt.geom.Point2D ll2,
                      java.awt.geom.Point2D point1,
                      java.awt.geom.Point2D point2)

Given a couple of points representing a bounding box, find out what the scale should be in order to make those points appear at the corners of the projection.

Specified by:

getScale in interface Projection

Overrides:

getScale in class GeoProj

Parameters:

ll1 - the upper left coordinates of the bounding box.

ll2 - the lower right coordinates of the bounding box.

point1 - a java.awt.Point reflecting a pixel spot on the projection that matches the ll1 coordinate, the upper left corner of the area of interest.

point2 - a java.awt.Point reflecting a pixel spot on the projection that matches the ll2 coordinate, usually the lower right corner of the area of interest.

drawBackground

public void drawBackground(java.awt.Graphics2D g,
                           java.awt.Paint paint)

Draw the background for the projection.

Overrides:

drawBackground in class Proj

Parameters:

g - Graphics2D

paint - java.awt.Paint to use for the background

drawBackground

public void drawBackground(java.awt.Graphics g)

Draw the background for the projection.

Overrides:

drawBackground in class Proj

Parameters:

g - Graphics

lambMsfn

public static double lambMsfn(double sinphi,
                              double cosphi,
                              double e)

Special function m = cos(phi) / sqrt(1.0 - (e*sin(phi))**2)

Parameters:

sinphi - double

cosphi - double

e - double

Returns:

double

lambTsfn

public static double lambTsfn(double phi,
                              double sinphi,
                              double e)

Special function t = tan(PI/4-phi/2) / pow((1-sinphi)/(1+sinphi), .5*e)

Parameters:

phi - double

sinphi - double

e - double

Returns:

double

main

public static void main(java.lang.String[] argv)

test method

Parameters:

argv - command line parameters