CrasterProjection.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.geom.*;
import com.jhlabs.map.*;

public class CrasterProjection extends Projection {

	private final static double XM = 0.97720502380583984317;
	private final static double RXM = 1.02332670794648848847;
	private final static double YM = 3.06998012383946546542;
	private final static double RYM = 0.32573500793527994772;
	private final static double THIRD = 0.333333333333333333;

	public Point2D.Double project(double lplam, double lpphi, Point2D.Double out) {
		lpphi *= THIRD;
		out.x = XM * lplam * (2. * Math.cos(lpphi + lpphi) - 1.);
		out.y = YM * Math.sin(lpphi);
		return out;
	}

	public Point2D.Double projectInverse(double xyx, double xyy, Point2D.Double out) {
		out.y = 3. * Math.asin(xyy * RYM);
		out.x = xyx * RXM / (2. * Math.cos((out.y + out.y) * THIRD) - 1);
		return out;
	}

	/**
	 * Returns true if this projection is equal area
	 */
	public boolean isEqualArea() {
		return true;
	}

	public boolean hasInverse() {
		return true;
	}

	public String toString() {
		return "Craster Parabolic (Putnins P4)";
	}

}