AitoffProjection.java

/*
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.
 */
package com.jhlabs.map.proj;

import java.awt.*;
import java.awt.geom.*;
import com.jhlabs.map.*;

public class AitoffProjection extends PseudoCylindricalProjection {
	
	protected final static int AITOFF = 0;
	protected final static int WINKEL = 1;

	private boolean winkel = false;
	private double cosphi1 = 0;

	public AitoffProjection() {
	}

	public AitoffProjection(int type, double projectionLatitude) {
		this.projectionLatitude = projectionLatitude;
		winkel = type == WINKEL;
	}

	public Point2D.Double project(double lplam, double lpphi, Point2D.Double out) {
		double c = 0.5 * lplam;
		double d = Math.acos(Math.cos(lpphi) * Math.cos(c));

		if (d != 0) {
			out.x = 2. * d * Math.cos(lpphi) * Math.sin(c) * (out.y = 1. / Math.sin(d));
			out.y *= d * Math.sin(lpphi);
		} else
			out.x = out.y = 0.0;
		if (winkel) {
			out.x = (out.x + lplam * cosphi1) * 0.5;
			out.y = (out.y + lpphi) * 0.5;
		}
		return out;
	}

	public void initialize() {
		super.initialize();
		if (winkel) {
//FIXME
//			if (pj_param(P->params, "tlat_1").i)
//				if ((cosphi1 = Math.cos(pj_param(P->params, "rlat_1").f)) == 0.)
//					throw new IllegalArgumentException("-22")
//			else /* 50d28' or acos(2/pi) */
				cosphi1 = 0.636619772367581343;
		}
	}
	
	public boolean hasInverse() {
		return false;
	}

	public String toString() {
		return winkel ? "Winkel Tripel" : "Aitoff";
	}

}