package org.opentrafficsim.core.gis;
   
   import java.io.Serializable;
   
   import nl.javel.gisbeans.io.esri.CoordinateTransform;
   
   /**
    * Transformation from lat-lon to X-Y in meters. Source: https://en.wikipedia.org/wiki/Geographic_coordinate_system.
    * <p>
   * Copyright (c) 2013-2018 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="http://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * $LastChangedDate: 2015-07-24 02:58:59 +0200 (Fri, 24 Jul 2015) $, @version $Revision: 1147 $, by $Author: averbraeck $,
   * initial version Nov 30, 2015 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public class CoordinateTransformLonLatToXY implements CoordinateTransform, Serializable
  {
      /** */
      private static final long serialVersionUID = 20151130L;
  
      /** The x-center of the center point (0, 0). */
      private double centerX = 0.0;
  
      /** The y-center of the center point (0, 0). */
      private double centerY = 0.0;
  
      /** The x-center of the center point (0, 0). */
      private final double lonCenter;
  
      /** The y-center of the center point (0, 0). */
      private final double latCenter;
  
      /** One percent of a lat degree to y meters. */
      private double latToM;
  
      /** One percent of a lon degree to x meters. */
      private double lonToM;
  
      /** Earth constants. */
      private static final double RE = 6378137;
  
      /** Earth constants. */
      private static final double RP = 6356752.31424518;
  
      /**
       * Transformation from: https://en.wikipedia.org/wiki/Geographic_coordinate_system.
       * @param latCenter the latitude of the center point (0, 0)
       * @param lonCenter the longitude of the center point (0, 0)
       */
      public CoordinateTransformLonLatToXY(final double lonCenter, final double latCenter)
      {
          super();
          this.latCenter = latCenter;
          this.lonCenter = lonCenter;
          double lr = Math.toRadians(latCenter);
          this.latToM = 111132.92 - 559.82 * Math.cos(2.0 * lr) + 1.175 * Math.cos(4.0 * lr) - 0.0023 * Math.cos(6.0 * lr); // 111.31;
          this.lonToM = 111412.84 * Math.cos(lr) - 93.5 * Math.cos(3.0 * lr) - 0.118 * Math.cos(5.0 * lr); // 88.32;
      }
  
      /** {@inheritDoc} */
      @Override
      public final float[] floatTransform(final double lon, final double lat)
      {
          double[] dt = doubleTransform(lon, lat);
          return new float[] { (float) dt[0], (float) dt[1] };
      }
  
      /**
       * Convert WGS84 coordinates to Cartesian coordinates.
       * @param lon double; longitude in degrees
       * @param lat double; latitude in degrees
       * @return double[]
       */
      public final double[] doubleTransformWSG84toCartesianXY(final double lon, final double lat)
      {
          double latrad = lat / 180.0 * Math.PI;
          double lonrad = lon / 180.0 * Math.PI;
  
          double coslat = Math.cos(latrad);
          double sinlat = Math.sin(latrad);
          double coslon = Math.cos(lonrad);
          double sinlon = Math.sin(lonrad);
  
          double term1 = (RE * RE * coslat) / Math.sqrt(RE * RE * coslat * coslat + RP * RP * sinlat * sinlat);
  
          double term2 = lat * coslat + term1;
  
          double x = coslon * term2 - this.centerX;
          double y = sinlon * term2 - this.centerY;
  
          return new double[] { x, y };
      }
  
      /** {@inheritDoc} */
      @Override
      public final double[] doubleTransform(final double lon, final double lat)
      {
         double x = (lon - this.lonCenter) * this.lonToM;
         double y = (lat - this.latCenter) * this.latToM;
 
         return new double[] { x, y };
     }
 
     /** {@inheritDoc} */
     @Override
     public final String toString()
     {
         return "CoordinateTransformLonLatToXY [centerX=" + this.centerX + ", centerY=" + this.centerY + ", lonCenter="
                 + this.lonCenter + ", latCenter=" + this.latCenter + ", latToM=" + this.latToM + ", lonToM=" + this.lonToM
                 + "]";
     }
 
 }