/*
Copyright 2006 Jerry Huxtable
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/*
* This file was semi-automatically converted from the public-domain USGS PROJ source.
*
* Bernhard Jenny, 23 September 2010: changed base class to AzimuthalProjection.
*/
package com.jhlabs.map.proj;
import java.awt.geom.*;
import com.jhlabs.map.*;
public class AiryProjection extends AzimuthalProjection {
private double p_halfpi;
private double sinph0;
private double cosph0;
private double Cb;
private int mode;
private boolean no_cut = true; /* do not cut at hemisphere limit */
private final static double EPS = 1.e-10;
private final static int N_POLE = 0;
private final static int S_POLE = 1;
private final static int EQUIT = 2;
private final static int OBLIQ = 3;
public AiryProjection() {
minLatitude = Math.toRadians(-60);
maxLatitude = Math.toRadians(60);
minLongitude = Math.toRadians(-90);
maxLongitude = Math.toRadians(90);
initialize();
}
public Point2D.Double project(double lplam, double lpphi, Point2D.Double out) {
double sinlam, coslam, cosphi, sinphi, t, s, Krho, cosz;
sinlam = Math.sin(lplam);
coslam = Math.cos(lplam);
switch (mode) {
case EQUIT:
case OBLIQ:
sinphi = Math.sin(lpphi);
cosphi = Math.cos(lpphi);
cosz = cosphi * coslam;
if (mode == OBLIQ)
cosz = sinph0 * sinphi + cosph0 * cosz;
if (!no_cut && cosz < -EPS)
throw new ProjectionException("F");
s = 1. - cosz;
if (Math.abs(s) > EPS) {
t = 0.5 * (1. + cosz);
Krho = -Math.log(t)/s - Cb / t;
} else
Krho = 0.5 - Cb;
out.x = Krho * cosphi * sinlam;
if (mode == OBLIQ)
out.y = Krho * (cosph0 * sinphi -
sinph0 * cosphi * coslam);
else
out.y = Krho * sinphi;
break;
case S_POLE:
case N_POLE:
out.y = Math.abs(p_halfpi - lpphi);
if (!no_cut && (lpphi - EPS) > MapMath.HALFPI)
throw new ProjectionException("F");
if ((out.y *= 0.5) > EPS) {
t = Math.tan(lpphi);
Krho = -2.*(Math.log(Math.cos(lpphi)) / t + t * Cb);
out.x = Krho * sinlam;
out.y = Krho * coslam;
if (mode == N_POLE)
out.y = -out.y;
} else
out.x = out.y = 0.;
}
return out;
}
public void initialize() { // airy
super.initialize();
double beta;
// no_cut = pj_param(params, "bno_cut").i;
// beta = 0.5 * (MapMath.HALFPI - pj_param(params, "rlat_b").f);
no_cut = false;//FIXME
beta = 0.5 * (MapMath.HALFPI - 0);//FIXME
if (Math.abs(beta) < EPS)
Cb = -0.5;
else {
Cb = 1./Math.tan(beta);
Cb *= Cb * Math.log(Math.cos(beta));
}
if (Math.abs(Math.abs(projectionLatitude) - MapMath.HALFPI) < EPS)
if (projectionLatitude < 0.) {
p_halfpi = -MapMath.HALFPI;
mode = S_POLE;
} else {
p_halfpi = MapMath.HALFPI;
mode = N_POLE;
}
else {
if (Math.abs(projectionLatitude) < EPS)
mode = EQUIT;
else {
mode = OBLIQ;
sinph0 = Math.sin(projectionLatitude);
cosph0 = Math.cos(projectionLatitude);
}
}
}
public String toString() {
return "Airy";
}
}