com.bbn.openmap.proj
Class CADRG

java.lang.Object
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  +--com.bbn.openmap.proj.Proj
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        +--com.bbn.openmap.proj.Cylindrical
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              +--com.bbn.openmap.proj.CADRG

All Implemented Interfaces:

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

public class CADRG

extends Cylindrical

implements EqualArc

Implements the CADRG projection. This is really an Equal Arc Projection with pixel spacings as dictated by the RPF specification.

See Also:

Serialized Form

Field Summary

static java.lang.String	CADRGName The CADRG name.
static int	CADRGType The CADRG type of projection.
static float	epsilon

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

half_world, world

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

ctrLat, ctrLon, DATELINE, height, maxscale, mercator, MIN_HEIGHT, MIN_WIDTH, minscale, NORTH_POLE, NUM_DEFAULT_CIRCLE_VERTS, NUM_DEFAULT_GREAT_SEGS, pixelsPerMeter, planetPixelCircumference, planetPixelRadius, planetRadius, projID, scale, scaled_radius, SOUTH_POLE, type, width, XSCALE_THRESHOLD, XTHRESHOLD

Constructor Summary

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

Method Summary

protected void	computeParameters() Called when some fundamental parameters change.
java.awt.Point	forward(float lat, float lon, java.awt.Point ret_val) Forward projects lat,lon coordinates.
java.awt.Point	forward(float lat, float lon, java.awt.Point ret_val, boolean b) Forward projects lat,lon into XY space and returns a Point.
java.awt.Point	forward(LatLonPoint pt, java.awt.Point ret_val) Projects a point from Lat/Lon space to X/Y space.
float	getLowerZoneExtent(int zone) Returns the lower zone extent for the given zone at the current scale.
java.lang.String	getName() Get the name string of the projection.
float	getPlanetPixelCircumference() Get the planet pixel circumference.
static int	getProjZone(char asciiZone) Given a letter for a zone, return the CADRG zone equivalent,
float	getScale(LatLonPoint ll1, LatLonPoint ll2, java.awt.Point point1, java.awt.Point 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.
float	getUpperZoneExtent(int zone) Returns the upper zone extent for the given zone at the current scale.
double	getXPixConstant() Returns the x pixel constant of the projection.
double	getYPixConstant() Returns the y pixel constant of the projection.
int	getZone() Returns the current zone of the projection.
LatLonPoint	inverse(int x, int y, LatLonPoint ret_val) Inverse project x,y coordinates into a LatLonPoint.
LatLonPoint	inverse(java.awt.Point pt, LatLonPoint ret_val) Inverse project a Point.
boolean	isPlotable(float lat, float lon) Checks if a LatLonPoint is plot-able.
float	normalize_latitude(float lat) Sets radian latitude to something sane.
int	numHorizontalFrames() Return the number of horizontal frame files that will fit around the world in the current zone.
int	numVerticalFrames() Return the number of vertical frame files that will fit within the current zone, overlaps included.
java.lang.String	toString() Return stringified description of this projection.

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

_forwardPoly, drawBackground, drawBackground, forwardRaw, getLowerRight, getUpperLeft, pan

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

clone, doPolyDispatch, equals, forward, forward, forwardArc, forwardArc, forwardArc, forwardCircle, forwardCircle, forwardCircle, forwardGreatPoly, forwardLine, forwardLine, forwardPoly, forwardPoly, forwardRaster, forwardRect, forwardRect, forwardRect, forwardRhumbPoly, getCenter, getHeight, getMaxScale, getMinScale, getPlanetPixelRadius, getPlanetRadius, getPPM, getProjectionID, getProjectionType, getScale, getWidth, hashCode, inverse, inverse, isComplicatedLineType, isPlotable, makeClone, pan, panE, panE, panN, panN, panNE, panNE, panNW, panNW, panS, panS, panSE, panSE, panSW, panSW, panW, panW, setCenter, setCenter, setHeight, setMaxScale, setMinScale, setParms, setPlanetRadius, setPPM, setProjectionID, setScale, setWidth, wrap_longitude

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bbn.openmap.proj.Projection

forward, forward, forwardArc, forwardCircle, forwardLine, forwardPoly, forwardRaster, forwardRaw, forwardRect, getCenter, getHeight, getLowerRight, getMaxScale, getMinScale, getProjectionID, getProjectionType, getScale, getUpperLeft, getWidth, inverse, inverse, isPlotable, makeClone, pan, pan

Field Detail

CADRGName

public static final transient java.lang.String CADRGName

The CADRG name.

See Also:

Constant Field Values

CADRGType

public static final transient int CADRGType

The CADRG type of projection.

See Also:

Constant Field Values

epsilon

public static final transient float epsilon

See Also:

Constant Field Values

Constructor Detail

CADRG

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

Construct a CADRG projection.

Parameters:

center - LatLonPoint center of projection

scale - float scale of projection

width - width of screen

height - height of screen

Method Detail

normalize_latitude

public float normalize_latitude(float lat)

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

Specified by:

normalize_latitude in class Proj

Parameters:

lat - float latitude in radians

Returns:

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

See Also:

LatLonPoint.normalize_latitude(float)

toString

public java.lang.String toString()

Return stringified description of this projection.

Overrides:

toString in class Cylindrical

Returns:

String

See Also:

Projection.getProjectionID()

getZone

public int getZone()

Returns the current zone of the projection. Zone number starts at 1, goes to 8, per the RPF specification. We don't handle zone 9 (polar).

Returns:

the zone of the projection.

getProjZone

public static int getProjZone(char asciiZone)

Given a letter for a zone, return the CADRG zone equivalent,

getPlanetPixelCircumference

public float getPlanetPixelCircumference()

Get the planet pixel circumference.

Overrides:

getPlanetPixelCircumference in class Proj

Returns:

float circumference of planet in pixels

getXPixConstant

public double getXPixConstant()

Returns the x pixel constant of the projection. This was calcuated when the projection was created. Represents the number of pixels around the earth (360 degrees).

Specified by:

getXPixConstant in interface EqualArc

getYPixConstant

public double getYPixConstant()

Returns the y pixel constant of the projection. This was calcuated when the projection was created. Represents the number of pixels from 0 to 90 degrees.

Specified by:

getYPixConstant in interface EqualArc

getUpperZoneExtent

public float getUpperZoneExtent(int zone)

Returns the upper zone extent for the given zone at the current scale. This only makes sense if the projection is at the same scale as the chart data you are interested in.

getLowerZoneExtent

public float getLowerZoneExtent(int zone)

Returns the lower zone extent for the given zone at the current scale. This only makes sense if the projection is at the same scale as the chart data you are interested in.

numHorizontalFrames

public int numHorizontalFrames()

Return the number of horizontal frame files that will fit around the world in the current zone. This only makes sense if the projection is at the same scale as the chart data you are interested in.

Returns:

number of frame columes in the current zone, to go around the world.

numVerticalFrames

public int numVerticalFrames()

Return the number of vertical frame files that will fit within the current zone, overlaps included. This only makes sense if the projection is at the same scale as the chart data you are interested in.

Returns:

number of frame rows in the current zone.

isPlotable

public boolean isPlotable(float lat,
                          float lon)

Checks if a LatLonPoint is plot-able.

A point is plot-able in the CADRG projection if it is within the North and South zone limits.

Specified by:

isPlotable in interface Projection

Parameters:

lat - float latitude in decimal degrees

lon - float longitude in decimal degrees

Returns:

boolean

forward

public java.awt.Point forward(LatLonPoint pt,
                              java.awt.Point ret_val)

Projects a point from Lat/Lon space to X/Y space.

Specified by:

forward in interface Projection

Parameters:

pt - LatLonPoint

ret_val - Point retval

Returns:

Point ret_val

forward

public java.awt.Point forward(float lat,
                              float lon,
                              java.awt.Point ret_val,
                              boolean b)

Forward projects lat,lon into XY space and returns a Point.

Specified by:

forward in interface Projection

Parameters:

lat - float latitude in radians

lon - float longitude in radians

ret_val - Resulting XY Point

b - placeholder argument indicating that lat,lon arguments are in radians (can be true or false)

Returns:

Point ret_val

See Also:

Projection.forward(float,float,Point)

forward

public java.awt.Point forward(float lat,
                              float lon,
                              java.awt.Point ret_val)

Forward projects lat,lon coordinates.

Specified by:

forward in interface Projection

Parameters:

lat - raw latitude in decimal degrees

lon - raw longitude in decimal degrees

ret_val - Resulting XY Point

Returns:

Point ret_val

inverse

public LatLonPoint inverse(java.awt.Point pt,
                           LatLonPoint ret_val)

Inverse project a Point.

Specified by:

inverse in interface Projection

Parameters:

pt - x,y Point

ret_val - resulting LatLonPoint

Returns:

LatLonPoint ret_val

inverse

public LatLonPoint inverse(int x,
                           int y,
                           LatLonPoint ret_val)

Inverse project x,y coordinates into a LatLonPoint.

Specified by:

inverse in interface Projection

Parameters:

x - integer x coordinate

y - integer y coordinate

ret_val - LatLonPoint

Returns:

LatLonPoint ret_val

See Also:

Proj.inverse(Point)

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" paramters used in the forward() and inverse() calls.

Overrides:

computeParameters in class Cylindrical

getName

public java.lang.String getName()

Get the name string of the projection.

Specified by:

getName in interface Projection

Overrides:

getName in class Cylindrical

getScale

public float getScale(LatLonPoint ll1,
                      LatLonPoint ll2,
                      java.awt.Point point1,
                      java.awt.Point 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 Proj

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.