/* 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 CylindricalEqualAreaProjection extends Projection { private double qp; private double[] apa; private double trueScaleLatitude; public CylindricalEqualAreaProjection() { this(0.0, 0.0, 0.0); } public CylindricalEqualAreaProjection(double projectionLatitude, double projectionLongitude, double trueScaleLatitude) { this.projectionLatitude = projectionLatitude; this.projectionLongitude = projectionLongitude; this.trueScaleLatitude = trueScaleLatitude; initialize(); } public void initialize() { super.initialize(); double t = trueScaleLatitude; scaleFactor = Math.cos(t); if (es != 0) { t = Math.sin(t); scaleFactor /= Math.sqrt(1. - es * t * t); apa = MapMath.authset(es); qp = MapMath.qsfn(1., e, one_es); } } public Point2D.Double project(double lam, double phi, Point2D.Double xy) { if (spherical) { xy.x = scaleFactor * lam; xy.y = Math.sin(phi) / scaleFactor; } else { xy.x = scaleFactor * lam; xy.y = .5 * MapMath.qsfn(Math.sin(phi), e, one_es) / scaleFactor; } return xy; } public Point2D.Double projectInverse(double x, double y, Point2D.Double lp) { if (spherical) { double t; if ((t = Math.abs(y *= scaleFactor)) - EPS10 <= 1.) { if (t >= 1.) lp.y = y < 0. ? -MapMath.HALFPI : MapMath.HALFPI; else lp.y = Math.asin(y); lp.x = x / scaleFactor; } else throw new ProjectionException(); } else { lp.y = MapMath.authlat(Math.asin( 2. * y * scaleFactor / qp), apa); lp.x = x / scaleFactor; } return lp; } public boolean hasInverse() { return true; } public boolean isRectilinear() { return true; } }