ucar.unidata.geoloc.projection.LatLonProjection Maven / Gradle / Ivy
The newest version!
/*
* Copyright (c) 1998-2018 University Corporation for Atmospheric Research/Unidata
* See LICENSE for license information.
*/
package ucar.unidata.geoloc.projection;
import ucar.nc2.constants.CF;
import ucar.unidata.geoloc.*;
import ucar.unidata.util.Format;
/**
* This is the "fake" identity projection where world coord = latlon coord.
* Topologically its the same as a cylinder tangent to the earth at the equator.
* The cylinder is cut at the "seam" = centerLon +- 180.
* Longitude values are always kept in the range [centerLon +-180]
*
* @author John Caron
* @see ProjectionImpl
*/
public class LatLonProjection extends ProjectionImpl {
/**
* center longitude
*/
private double centerLon = 0.0;
private Earth earth = EarthEllipsoid.DEFAULT;
@Override
public ProjectionImpl constructCopy() {
LatLonProjection result = new LatLonProjection(getName(), getDefaultMapArea());
result.setDefaultMapArea(defaultMapArea);
result.setName(name);
result.earth = this.earth;
return result;
}
/**
* Default constructor
*/
public LatLonProjection() {
this("LatLonProjection");
addParameters();
}
public LatLonProjection(Earth earth) {
this("LatLonProjection");
this.earth = earth;
addParameters();
}
/**
* Create a new LatLonProjection
*
* @param name name of projection
*/
public LatLonProjection(String name) {
this(name, new ProjectionRect(-180, -90, 180, 90));
addParameters();
}
/**
* Create a new LatLonProjection
*
* @param name name of projection
* @param defaultMapArea bounding box
*/
public LatLonProjection(String name, ProjectionRect defaultMapArea) {
super(name, true);
this.defaultMapArea = defaultMapArea;
addParameters();
}
private void addParameters() {
addParameter(CF.GRID_MAPPING_NAME, CF.LATITUDE_LONGITUDE);
if (earth.isSpherical())
addParameter(CF.EARTH_RADIUS, earth.getEquatorRadius());
else {
addParameter(CF.SEMI_MAJOR_AXIS, earth.getEquatorRadius());
addParameter(CF.SEMI_MINOR_AXIS, earth.getPoleRadius());
}
}
/**
* Get the label to be used in the gui for this type of projection
*
* @return Type label
*/
public String getProjectionTypeLabel() {
return "Lat/Lon";
}
/**
* Get a String of the parameters
*
* @return a String of the parameters
*/
public String paramsToString() {
return "Center lon:" + Format.d(centerLon, 3);
}
/**
* See if this projection equals the object in question
*
* @param o object in question
* @return true if it is a LatLonProjection and covers the same area
*/
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
LatLonProjection that = (LatLonProjection) o;
if ((defaultMapArea == null) != (that.defaultMapArea == null)) return false; // common case is that these are null
if (defaultMapArea != null && !that.defaultMapArea.equals(defaultMapArea)) return false;
return Double.compare(that.centerLon, centerLon) == 0;
}
@Override
public int hashCode() {
int result;
long temp;
temp = Double.doubleToLongBits(centerLon);
result = (int) (temp ^ (temp >>> 32));
if (defaultMapArea != null)
result = 31 * result + defaultMapArea.hashCode();
return result;
}
/**
* Convert a LatLonPoint to projection coordinates
*
* @param latlon convert from these lat, lon coordinates
* @param result the object to write to
* @return the given result
*/
public ProjectionPoint latLonToProj(LatLonPoint latlon, ProjectionPointImpl result) {
result.setLocation(LatLonPointImpl.lonNormal(latlon.getLongitude(),
centerLon), latlon.getLatitude());
return result;
}
/**
* Convert projection coordinates to a LatLonPoint
* Note: a new object is not created on each call for the return value.
*
* @param world convert from these projection coordinates
* @param result the object to write to
* @return LatLonPoint convert to these lat/lon coordinates
*/
public LatLonPoint projToLatLon(ProjectionPoint world, LatLonPointImpl result) {
result.setLongitude(world.getX());
result.setLatitude(world.getY());
return result;
}
/**
* Convert projection coordinates to lat/lon coordinate.
*
* @param from array of projection coordinates: from[2][n], where
* (from[0][i], from[1][i]) is the (x, y) coordinate
* of the ith point
* @param to resulting array of lat/lon coordinates: to[2][n] where
* (to[0][i], to[1][i]) is the (lat, lon) coordinate of
* the ith point
* @return the "to" array
*/
public float[][] projToLatLon(float[][] from, float[][] to) {
float[] fromX = from[INDEX_X];
float[] fromY = from[INDEX_Y];
to[INDEX_LAT] = fromY;
to[INDEX_LON] = fromX;
return to;
}
/**
* Convert lat/lon coordinates to projection coordinates.
*
* @param from array of lat/lon coordinates: from[2][n], where
* (from[latIndex][i], from[lonIndex][i]) is the (lat,lon)
* coordinate of the ith point
* @param to resulting array of projection coordinates: to[2][n]
* where (to[0][i], to[1][i]) is the (x,y) coordinate of
* the ith point
* @param latIndex index of lat coordinate; must be 0 or 1
* @param lonIndex index of lon coordinate; must be 0 or 1
* @return the "to" array
*/
public float[][] latLonToProj(float[][] from, float[][] to, int latIndex,
int lonIndex) {
int cnt = from[0].length;
float[] toX = to[INDEX_X];
float[] toY = to[INDEX_Y];
float[] fromLat = from[latIndex];
float[] fromLon = from[lonIndex];
float lat, lon;
for (int i = 0; i < cnt; i++) {
lat = fromLat[i];
lon = (float) (centerLon + Math.IEEEremainder(fromLon[i] - centerLon, 360.0));
toX[i] = lon;
toY[i] = lat;
}
return to;
}
/**
* Convert projection coordinates to lat/lon coordinate.
*
* @param from array of projection coordinates: from[2][n], where
* (from[0][i], from[1][i]) is the (x, y) coordinate
* of the ith point
* @param to resulting array of lat/lon coordinates: to[2][n] where
* (to[0][i], to[1][i]) is the (lat, lon) coordinate of
* the ith point
* @return the "to" array
*/
public double[][] projToLatLon(double[][] from, double[][] to) {
double[] fromX = from[INDEX_X];
double[] fromY = from[INDEX_Y];
to[INDEX_LAT] = fromY;
to[INDEX_LON] = fromX;
return to;
}
/**
* Convert lat/lon coordinates to projection coordinates.
*
* @param from array of lat/lon coordinates: from[2][n], where
* (from[latIndex][i], from[lonIndex][i]) is the (lat,lon)
* coordinate of the ith point
* @param to resulting array of projection coordinates: to[2][n]
* where (to[0][i], to[1][i]) is the (x,y) coordinate of
* the ith point
* @param latIndex index of lat coordinate; must be 0 or 1
* @param lonIndex index of lon coordinate; must be 0 or 1
* @return the "to" array
*/
public double[][] latLonToProj(double[][] from, double[][] to,
int latIndex, int lonIndex) {
int cnt = from[0].length;
double[] toX = to[INDEX_X];
double[] toY = to[INDEX_Y];
double[] fromLat = from[latIndex];
double[] fromLon = from[lonIndex];
double lat, lon;
for (int i = 0; i < cnt; i++) {
lat = fromLat[i];
lon = centerLon + Math.IEEEremainder(fromLon[i] - centerLon, 360.0);
toX[i] = lon;
toY[i] = lat;
}
return to;
}
/**
* Set the center of the Longitude range. It is normalized to +/- 180.
* The cylinder is cut at the "seam" = centerLon +- 180.
* Use this to keep the Longitude values kept in the range [centerLon +-180], which
* makes seam handling easier.
*
* @param centerLon the center of the Longitude range.
* @return centerLon normalized to +/- 180.
*/
public double setCenterLon(double centerLon) {
this.centerLon = LatLonPointImpl.lonNormal(centerLon);
return this.centerLon;
}
/**
* Get the center of the Longitude range. It is normalized to +/- 180.
*
* @return the center longitude
*/
public double getCenterLon() {
return centerLon;
}
/**
* Does the line between these two points cross the projection "seam".
*
* @param pt1 the line goes between these two points
* @param pt2 the line goes between these two points
* @return false if there is no seam
*/
public boolean crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) {
return Math.abs(pt1.getX() - pt2.getX()) > 270.0; // ?? LOOK: do I believe this
}
/**
* Set a reasonable bounding box for this projection.
*
* @param bb a reasonable bounding box
*/
public void setDefaultMapArea(ProjectionRect bb) {
super.setDefaultMapArea(bb);
this.centerLon = bb.getCenterX();
// setCenterLon( bb.getCenterX());
}
/**
* Split a latlon rectangle to the equivalent ProjectionRect
* using this LatLonProjection to split it at the seam if needed.
*
* @param latlonR the latlon rectangle to transform
* @return 1 or 2 ProjectionRect. If it doesnt cross the seam,
* the second rectangle is null.
*/
public ProjectionRect[] latLonToProjRect(LatLonRect latlonR) {
double lat0 = latlonR.getLowerLeftPoint().getLatitude();
double height = Math.abs(latlonR.getUpperRightPoint().getLatitude() - lat0);
double width = latlonR.getWidth();
double lon0 = LatLonPointImpl.lonNormal(
latlonR.getLowerLeftPoint().getLongitude(),
centerLon);
double lon1 = LatLonPointImpl.lonNormal(
latlonR.getUpperRightPoint().getLongitude(),
centerLon);
ProjectionRect[] rects = new ProjectionRect[] {new ProjectionRect(), new ProjectionRect()};
if (lon0 < lon1) {
rects[0].setRect(lon0, lat0, width, height);
rects[1] = null;
} else {
double y = centerLon + 180 - lon0;
rects[0].setRect(lon0, lat0, y, height);
rects[1].setRect(lon1 - width + y, lat0, width - y, height);
}
return rects;
}
public LatLonRect projToLatLonBB(ProjectionRect world) {
double startLat = world.getMinY();
double startLon = world.getMinX();
double deltaLat = world.getHeight();
double deltaLon = world.getWidth();
LatLonPoint llpt = new LatLonPointImpl(startLat, startLon);
return new LatLonRect(llpt, deltaLat, deltaLon);
}
/**
* projection rect 1
*/
//private ProjectionRect projR1 = new ProjectionRect();
/**
* projection rect 1
*/
//private ProjectionRect projR2 = new ProjectionRect();
/**
* array fo rects
*/
//private ProjectionRect rects[] = new ProjectionRect[2];
/**
* Create a latlon rectangle and split it into the equivalent
* ProjectionRect using this LatLonProjection. The latlon rect is
* constructed from 2 lat/lon points. The lon values are considered
* coords in the latlonProjection, and so do not have to be +/- 180.
*
* @param lat0 lat of point 1
* @param lon0 lon of point 1
* @param lat1 lat of point 1
* @param lon1 lon of point 1
* @return 1 or 2 ProjectionRect. If it doesnt cross the seam,
* the second rectangle is null.
*/
public ProjectionRect[] latLonToProjRect(double lat0, double lon0, double lat1, double lon1) {
double height = Math.abs(lat1 - lat0);
lat0 = Math.min(lat1, lat0);
double width = lon1 - lon0;
if (width < 1.0e-8) {
width = 360.0; // assume its the whole thing
}
lon0 = LatLonPointImpl.lonNormal(lon0, centerLon);
lon1 = LatLonPointImpl.lonNormal(lon1, centerLon);
ProjectionRect[] rects = new ProjectionRect[] {new ProjectionRect(), new ProjectionRect()};
if (width >= 360.0) {
rects[0].setRect(centerLon - 180.0, lat0, 360.0, height);
rects[1] = null;
} else if (lon0 < lon1) {
rects[0].setRect(lon0, lat0, width, height);
rects[1] = null;
} else {
double y = centerLon + 180 - lon0;
rects[0].setRect(lon0, lat0, y, height);
rects[1].setRect(lon1 - width + y, lat0, width - y, height);
}
return rects;
}
}