source: trunk/workshop-routing-foss4g/web/proj4js/lib/proj4js.js @ 77

/*
Author:       Mike Adair madairATdmsolutions.ca
              Richard Greenwood rich@greenwoodmap.com
License:      LGPL as per: http://www.gnu.org/copyleft/lesser.html

$Id: Proj.js 2956 2007-07-09 12:17:52Z steven $
*/

/**
 * Namespace: Proj4js
 *
 * Proj4js is a JavaScript library to transform point coordinates from one 
 * coordinate system to another, including datum transformations.
 *
 * This library is a port of both the Proj.4 and GCTCP C libraries to JavaScript. 
 * Enabling these transformations in the browser allows geographic data stored 
 * in different projections to be combined in browser-based web mapping 
 * applications.
 * 
 * Proj4js must have access to coordinate system initialization strings (which
 * are the same as for PROJ.4 command line).  Thes can be included in your 
 * application using a <script> tag or Proj4js can load CS initialization 
 * strings from a local directory or a web service such as spatialreference.org.
 *
 * Similarly, Proj4js must have access to projection transform code.  These can
 * be included individually using a <script> tag in your page, built into a 
 * custom build of Proj4js or loaded dynamically at run-time.  Using the
 * -combined and -compressed versions of Proj4js includes all projection class
 * code by default.
 *
 * Note that dynamic loading of defs and code happens ascynchrously, check the
 * Proj.readyToUse flag before using the Proj object.  If the defs and code
 * required by your application are loaded through script tags, dynamic loading
 * is not required and the Proj object will be readyToUse on return from the 
 * constructor.
 * 
 * All coordinates are handled as points which have a .x and a .y property
 * which will be modified in place.
 *
 * Override Proj4js.reportError for output of alerts and warnings.
 *
 * See http://trac.osgeo.org/proj4js/wiki/UserGuide for full details.
*/

/**
 * Global namespace object for Proj4js library
 */
Proj4js = {

    /**
     * Property: defaultDatum
     * The datum to use when no others a specified
     */
    defaultDatum: 'WGS84',                  //default datum

    /** 
    * Method: transform(source, dest, point)
    * Transform a point coordinate from one map projection to another.  This is
    * really the only public method you should need to use.
    *
    * Parameters:
    * source - {Proj4js.Proj} source map projection for the transformation
    * dest - {Proj4js.Proj} destination map projection for the transformation
    * point - {Object} point to transform, may be geodetic (long, lat) or
    *     projected Cartesian (x,y), but should always have x,y properties.
    */
    transform: function(source, dest, point) {
        if (!source.readyToUse) {
            this.reportError("Proj4js initialization for:"+source.srsCode+" not yet complete");
            return point;
        }
        if (!dest.readyToUse) {
            this.reportError("Proj4js initialization for:"+dest.srsCode+" not yet complete");
            return point;
        }
        
        // Workaround for Spherical Mercator
        if ((source.srsProjNumber =="900913" && dest.datumCode != "WGS84" && !dest.datum_params) ||
            (dest.srsProjNumber == "900913" && source.datumCode != "WGS84" && !source.datum_params)) {
            var wgs84 = Proj4js.WGS84;
            this.transform(source, wgs84, point);
            source = wgs84;
        }

        // DGR, 2010/11/12
        if (source.axis!="enu") {
            this.adjust_axis(source,false,point);
        }

        // Transform source points to long/lat, if they aren't already.
        if ( source.projName=="longlat") {
            point.x *= Proj4js.common.D2R;  // convert degrees to radians
            point.y *= Proj4js.common.D2R;
        } else {
            if (source.to_meter) {
                point.x *= source.to_meter;
                point.y *= source.to_meter;
            }
            source.inverse(point); // Convert Cartesian to longlat
        }

        // Adjust for the prime meridian if necessary
        if (source.from_greenwich) { 
            point.x += source.from_greenwich; 
        }

        // Convert datums if needed, and if possible.
        point = this.datum_transform( source.datum, dest.datum, point );

        // Adjust for the prime meridian if necessary
        if (dest.from_greenwich) {
            point.x -= dest.from_greenwich;
        }

        if( dest.projName=="longlat" ) {             
            // convert radians to decimal degrees
            point.x *= Proj4js.common.R2D;
            point.y *= Proj4js.common.R2D;
        } else  {               // else project
            dest.forward(point);
            if (dest.to_meter) {
                point.x /= dest.to_meter;
                point.y /= dest.to_meter;
            }
        }

        // DGR, 2010/11/12
        if (dest.axis!="enu") {
            this.adjust_axis(dest,true,point);
        }

        return point;
    }, // transform()

    /** datum_transform()
      source coordinate system definition,
      destination coordinate system definition,
      point to transform in geodetic coordinates (long, lat, height)
    */
    datum_transform : function( source, dest, point ) {

      // Short cut if the datums are identical.
      if( source.compare_datums( dest ) ) {
          return point; // in this case, zero is sucess,
                    // whereas cs_compare_datums returns 1 to indicate TRUE
                    // confusing, should fix this
      }

      // Explicitly skip datum transform by setting 'datum=none' as parameter for either source or dest
      if( source.datum_type == Proj4js.common.PJD_NODATUM
          || dest.datum_type == Proj4js.common.PJD_NODATUM) {
          return point;
      }

      // If this datum requires grid shifts, then apply it to geodetic coordinates.
      if( source.datum_type == Proj4js.common.PJD_GRIDSHIFT )
      {
        alert("ERROR: Grid shift transformations are not implemented yet.");
        /*
          pj_apply_gridshift( pj_param(source.params,"snadgrids").s, 0,
                              point_count, point_offset, x, y, z );
          CHECK_RETURN;

          src_a = SRS_WGS84_SEMIMAJOR;
          src_es = 0.006694379990;
        */
      }

      if( dest.datum_type == Proj4js.common.PJD_GRIDSHIFT )
      {
        alert("ERROR: Grid shift transformations are not implemented yet.");
        /*
          dst_a = ;
          dst_es = 0.006694379990;
        */
      }

      // Do we need to go through geocentric coordinates?
      if( source.es != dest.es || source.a != dest.a
          || source.datum_type == Proj4js.common.PJD_3PARAM
          || source.datum_type == Proj4js.common.PJD_7PARAM
          || dest.datum_type == Proj4js.common.PJD_3PARAM
          || dest.datum_type == Proj4js.common.PJD_7PARAM)
      {

        // Convert to geocentric coordinates.
        source.geodetic_to_geocentric( point );
        // CHECK_RETURN;

        // Convert between datums
        if( source.datum_type == Proj4js.common.PJD_3PARAM || source.datum_type == Proj4js.common.PJD_7PARAM ) {
          source.geocentric_to_wgs84(point);
          // CHECK_RETURN;
        }

        if( dest.datum_type == Proj4js.common.PJD_3PARAM || dest.datum_type == Proj4js.common.PJD_7PARAM ) {
          dest.geocentric_from_wgs84(point);
          // CHECK_RETURN;
        }

        // Convert back to geodetic coordinates
        dest.geocentric_to_geodetic( point );
          // CHECK_RETURN;
      }

      // Apply grid shift to destination if required
      if( dest.datum_type == Proj4js.common.PJD_GRIDSHIFT )
      {
        alert("ERROR: Grid shift transformations are not implemented yet.");
        // pj_apply_gridshift( pj_param(dest.params,"snadgrids").s, 1, point);
        // CHECK_RETURN;
      }
      return point;
    }, // cs_datum_transform

    /**
     * Function: adjust_axis
     * Normalize or de-normalized the x/y/z axes.  The normal form is "enu"
     * (easting, northing, up).
     * Parameters:
     * crs {Proj4js.Proj} the coordinate reference system
     * denorm {Boolean} when false, normalize
     * point {Object} the coordinates to adjust
     */
    adjust_axis: function(crs, denorm, point) {
        var xin= point.x, yin= point.y, zin= point.z || 0.0;
        var v, t;
        for (var i= 0; i<3; i++) {
            if (denorm && i==2 && point.z===undefined) { continue; }
                 if (i==0) { v= xin; t= 'x'; }
            else if (i==1) { v= yin; t= 'y'; }
            else           { v= zin; t= 'z'; }
            switch(crs.axis[i]) {
            case 'e':
                point[t]= v;
                break;
            case 'w':
                point[t]= -v;
                break;
            case 'n':
                point[t]= v;
                break;
            case 's':
                point[t]= -v;
                break;
            case 'u':
                if (point[t]!==undefined) { point.z= v; }
                break;
            case 'd':
                if (point[t]!==undefined) { point.z= -v; }
                break;
            default :
                alert("ERROR: unknow axis ("+crs.axis[i]+") - check definition of "+src.projName);
                return null;
            }
        }
        return point;
    },

    /**
     * Function: reportError
     * An internal method to report errors back to user. 
     * Override this in applications to report error messages or throw exceptions.
     */
    reportError: function(msg) {
      //console.log(msg);
    },

/**
 *
 * Title: Private Methods
 * The following properties and methods are intended for internal use only.
 *
 * This is a minimal implementation of JavaScript inheritance methods so that 
 * Proj4js can be used as a stand-alone library.
 * These are copies of the equivalent OpenLayers methods at v2.7
 */
 
/**
 * Function: extend
 * Copy all properties of a source object to a destination object.  Modifies
 *     the passed in destination object.  Any properties on the source object
 *     that are set to undefined will not be (re)set on the destination object.
 *
 * Parameters:
 * destination - {Object} The object that will be modified
 * source - {Object} The object with properties to be set on the destination
 *
 * Returns:
 * {Object} The destination object.
 */
    extend: function(destination, source) {
      destination = destination || {};
      if(source) {
          for(var property in source) {
              var value = source[property];
              if(value !== undefined) {
                  destination[property] = value;
              }
          }
      }
      return destination;
    },

/**
 * Constructor: Class
 * Base class used to construct all other classes. Includes support for 
 *     multiple inheritance. 
 *  
 */
    Class: function() {
      var Class = function() {
          this.initialize.apply(this, arguments);
      };
  
      var extended = {};
      var parent;
      for(var i=0; i<arguments.length; ++i) {
          if(typeof arguments[i] == "function") {
              // get the prototype of the superclass
              parent = arguments[i].prototype;
          } else {
              // in this case we're extending with the prototype
              parent = arguments[i];
          }
          Proj4js.extend(extended, parent);
      }
      Class.prototype = extended;
      
      return Class;
    },

    /**
     * Function: bind
     * Bind a function to an object.  Method to easily create closures with
     *     'this' altered.
     * 
     * Parameters:
     * func - {Function} Input function.
     * object - {Object} The object to bind to the input function (as this).
     * 
     * Returns:
     * {Function} A closure with 'this' set to the passed in object.
     */
    bind: function(func, object) {
        // create a reference to all arguments past the second one
        var args = Array.prototype.slice.apply(arguments, [2]);
        return function() {
            // Push on any additional arguments from the actual function call.
            // These will come after those sent to the bind call.
            var newArgs = args.concat(
                Array.prototype.slice.apply(arguments, [0])
            );
            return func.apply(object, newArgs);
        };
    },
    
/**
 * The following properties and methods handle dynamic loading of JSON objects.
 */
 
    /**
     * Property: scriptName
     * {String} The filename of this script without any path.
     */
    scriptName: "proj4js.js",

    /**
     * Property: defsLookupService
     * AJAX service to retreive projection definition parameters from
     */
    defsLookupService: 'http://spatialreference.org/ref',

    /**
     * Property: libPath
     * internal: http server path to library code.
     */
    libPath: null,

    /**
     * Function: getScriptLocation
     * Return the path to this script.
     *
     * Returns:
     * Path to this script
     */
    getScriptLocation: function () {
        if (this.libPath) return this.libPath;
        var scriptName = this.scriptName;
        var scriptNameLen = scriptName.length;

        var scripts = document.getElementsByTagName('script');
        for (var i = 0; i < scripts.length; i++) {
            var src = scripts[i].getAttribute('src');
            if (src) {
                var index = src.lastIndexOf(scriptName);
                // is it found, at the end of the URL?
                if ((index > -1) && (index + scriptNameLen == src.length)) {
                    this.libPath = src.slice(0, -scriptNameLen);
                    break;
                }
            }
        }
        return this.libPath||"";
    },

    /**
     * Function: loadScript
     * Load a JS file from a URL into a <script> tag in the page.
     * 
     * Parameters:
     * url - {String} The URL containing the script to load
     * onload - {Function} A method to be executed when the script loads successfully
     * onfail - {Function} A method to be executed when there is an error loading the script
     * loadCheck - {Function} A boolean method that checks to see if the script 
     *            has loaded.  Typically this just checks for the existance of
     *            an object in the file just loaded.
     */
    loadScript: function(url, onload, onfail, loadCheck) {
      var script = document.createElement('script');
      script.defer = false;
      script.type = "text/javascript";
      script.id = url;
      script.src = url;
      script.onload = onload;
      script.onerror = onfail;
      script.loadCheck = loadCheck;
      if (/MSIE/.test(navigator.userAgent)) {
        script.onreadystatechange = this.checkReadyState;
      }
      document.getElementsByTagName('head')[0].appendChild(script);
    },
    
    /**
     * Function: checkReadyState
     * IE workaround since there is no onerror handler.  Calls the user defined 
     * loadCheck method to determine if the script is loaded.
     * 
     */
    checkReadyState: function() {
      if (this.readyState == 'loaded') {
        if (!this.loadCheck()) {
          this.onerror();
        } else {
          this.onload();
        }
      }
    }
};

/**
 * Class: Proj4js.Proj
 *
 * Proj objects provide transformation methods for point coordinates
 * between geodetic latitude/longitude and a projected coordinate system. 
 * once they have been initialized with a projection code.
 *
 * Initialization of Proj objects is with a projection code, usually EPSG codes,
 * which is the key that will be used with the Proj4js.defs array.
 * 
 * The code passed in will be stripped of colons and converted to uppercase
 * to locate projection definition files.
 *
 * A projection object has properties for units and title strings.
 */
Proj4js.Proj = Proj4js.Class({

  /**
   * Property: readyToUse
   * Flag to indicate if initialization is complete for this Proj object
   */
  readyToUse: false,   
  
  /**
   * Property: title
   * The title to describe the projection
   */
  title: null,  
  
  /**
   * Property: projName
   * The projection class for this projection, e.g. lcc (lambert conformal conic,
   * or merc for mercator).  These are exactly equivalent to their Proj4 
   * counterparts.
   */
  projName: null,
  /**
   * Property: units
   * The units of the projection.  Values include 'm' and 'degrees'
   */
  units: null,
  /**
   * Property: datum
   * The datum specified for the projection
   */
  datum: null,
  /**
   * Property: x0
   * The x coordinate origin
   */
  x0: 0,
  /**
   * Property: y0
   * The y coordinate origin
   */
  y0: 0,
  /**
   * Property: localCS
   * Flag to indicate if the projection is a local one in which no transforms
   * are required.
   */
  localCS: false,

  /**
  * Property: queue
  * Buffer (FIFO) to hold callbacks waiting to be called when projection loaded.
  */
  queue: null,

  /**
  * Constructor: initialize
  * Constructor for Proj4js.Proj objects
  *
  * Parameters:
  * srsCode - a code for map projection definition parameters.  These are usually
  * (but not always) EPSG codes.
  */
  initialize: function(srsCode, callback) {
      this.srsCodeInput = srsCode;
      
      //Register callbacks prior to attempting to process definition
      this.queue = [];
      if( callback ){
           this.queue.push( callback );
      }
      
      //check to see if this is a WKT string
      if ((srsCode.indexOf('GEOGCS') >= 0) ||
          (srsCode.indexOf('GEOCCS') >= 0) ||
          (srsCode.indexOf('PROJCS') >= 0) ||
          (srsCode.indexOf('LOCAL_CS') >= 0)) {
            this.parseWKT(srsCode);
            this.deriveConstants();
            this.loadProjCode(this.projName);
            return;
      }
      
      // DGR 2008-08-03 : support urn and url
      if (srsCode.indexOf('urn:') == 0) {
          //urn:ORIGINATOR:def:crs:CODESPACE:VERSION:ID
          var urn = srsCode.split(':');
          if ((urn[1] == 'ogc' || urn[1] =='x-ogc') &&
              (urn[2] =='def') &&
              (urn[3] =='crs')) {
              srsCode = urn[4]+':'+urn[urn.length-1];
          }
      } else if (srsCode.indexOf('http://') == 0) {
          //url#ID
          var url = srsCode.split('#');
          if (url[0].match(/epsg.org/)) {
            // http://www.epsg.org/#
            srsCode = 'EPSG:'+url[1];
          } else if (url[0].match(/RIG.xml/)) {
            //http://librairies.ign.fr/geoportail/resources/RIG.xml#
            //http://interop.ign.fr/registers/ign/RIG.xml#
            srsCode = 'IGNF:'+url[1];
          }
      }
      this.srsCode = srsCode.toUpperCase();
      if (this.srsCode.indexOf("EPSG") == 0) {
          this.srsCode = this.srsCode;
          this.srsAuth = 'epsg';
          this.srsProjNumber = this.srsCode.substring(5);
      // DGR 2007-11-20 : authority IGNF
      } else if (this.srsCode.indexOf("IGNF") == 0) {
          this.srsCode = this.srsCode;
          this.srsAuth = 'IGNF';
          this.srsProjNumber = this.srsCode.substring(5);
      // DGR 2008-06-19 : pseudo-authority CRS for WMS
      } else if (this.srsCode.indexOf("CRS") == 0) {
          this.srsCode = this.srsCode;
          this.srsAuth = 'CRS';
          this.srsProjNumber = this.srsCode.substring(4);
      } else {
          this.srsAuth = '';
          this.srsProjNumber = this.srsCode;
      }
      
      this.loadProjDefinition();
  },
  
/**
 * Function: loadProjDefinition
 *    Loads the coordinate system initialization string if required.
 *    Note that dynamic loading happens asynchronously so an application must 
 *    wait for the readyToUse property is set to true.
 *    To prevent dynamic loading, include the defs through a script tag in
 *    your application.
 *
 */
    loadProjDefinition: function() {
      //check in memory
      if (Proj4js.defs[this.srsCode]) {
        this.defsLoaded();
        return;
      }

      //else check for def on the server
      var url = Proj4js.getScriptLocation() + 'defs/' + this.srsAuth.toUpperCase() + this.srsProjNumber + '.js';
      Proj4js.loadScript(url, 
                Proj4js.bind(this.defsLoaded, this),
                Proj4js.bind(this.loadFromService, this),
                Proj4js.bind(this.checkDefsLoaded, this) );
    },

/**
 * Function: loadFromService
 *    Creates the REST URL for loading the definition from a web service and 
 *    loads it.
 *
 */
    loadFromService: function() {
      //else load from web service
      var url = Proj4js.defsLookupService +'/' + this.srsAuth +'/'+ this.srsProjNumber + '/proj4js/';
      Proj4js.loadScript(url, 
            Proj4js.bind(this.defsLoaded, this),
            Proj4js.bind(this.defsFailed, this),
            Proj4js.bind(this.checkDefsLoaded, this) );
    },

/**
 * Function: defsLoaded
 * Continues the Proj object initilization once the def file is loaded
 *
 */
    defsLoaded: function() {
      this.parseDefs();
      this.loadProjCode(this.projName);
    },
    
/**
 * Function: checkDefsLoaded
 *    This is the loadCheck method to see if the def object exists
 *
 */
    checkDefsLoaded: function() {
      if (Proj4js.defs[this.srsCode]) {
        return true;
      } else {
        return false;
      }
    },

 /**
 * Function: defsFailed
 *    Report an error in loading the defs file, but continue on using WGS84
 *
 */
   defsFailed: function() {
      Proj4js.reportError('failed to load projection definition for: '+this.srsCode);
      Proj4js.defs[this.srsCode] = Proj4js.defs['WGS84'];  //set it to something so it can at least continue
      this.defsLoaded();
    },

/**
 * Function: loadProjCode
 *    Loads projection class code dynamically if required.
 *     Projection code may be included either through a script tag or in
 *     a built version of proj4js
 *
 */
    loadProjCode: function(projName) {
      if (Proj4js.Proj[projName]) {
        this.initTransforms();
        return;
      }

      //the URL for the projection code
      var url = Proj4js.getScriptLocation() + 'projCode/' + projName + '.js';
      Proj4js.loadScript(url, 
              Proj4js.bind(this.loadProjCodeSuccess, this, projName),
              Proj4js.bind(this.loadProjCodeFailure, this, projName), 
              Proj4js.bind(this.checkCodeLoaded, this, projName) );
    },

 /**
 * Function: loadProjCodeSuccess
 *    Loads any proj dependencies or continue on to final initialization.
 *
 */
    loadProjCodeSuccess: function(projName) {
      if (Proj4js.Proj[projName].dependsOn){
        this.loadProjCode(Proj4js.Proj[projName].dependsOn);
      } else {
        this.initTransforms();
      }
    },

 /**
 * Function: defsFailed
 *    Report an error in loading the proj file.  Initialization of the Proj
 *    object has failed and the readyToUse flag will never be set.
 *
 */
    loadProjCodeFailure: function(projName) {
      Proj4js.reportError("failed to find projection file for: " + projName);
      //TBD initialize with identity transforms so proj will still work?
    },
    
/**
 * Function: checkCodeLoaded
 *    This is the loadCheck method to see if the projection code is loaded
 *
 */
    checkCodeLoaded: function(projName) {
      if (Proj4js.Proj[projName]) {
        return true;
      } else {
        return false;
      }
    },

/**
 * Function: initTransforms
 *    Finalize the initialization of the Proj object
 *
 */
    initTransforms: function() {
      Proj4js.extend(this, Proj4js.Proj[this.projName]);
      this.init();
      this.readyToUse = true;
      if( this.queue ) {
        var item;
        while( (item = this.queue.shift()) ) {
          item.call( this, this );
        }
      }
  },

/**
 * Function: parseWKT
 * Parses a WKT string to get initialization parameters
 *
 */
 wktRE: /^(\w+)\[(.*)\]$/,
 parseWKT: function(wkt) {
    var wktMatch = wkt.match(this.wktRE);
    if (!wktMatch) return;
    var wktObject = wktMatch[1];
    var wktContent = wktMatch[2];
    var wktTemp = wktContent.split(",");
    var wktName;
    if (wktObject.toUpperCase() == "TOWGS84") {
      wktName = wktObject;  //no name supplied for the TOWGS84 array
    } else {
      wktName = wktTemp.shift();
    }
    wktName = wktName.replace(/^\"/,"");
    wktName = wktName.replace(/\"$/,"");
    
    /*
    wktContent = wktTemp.join(",");
    var wktArray = wktContent.split("],");
    for (var i=0; i<wktArray.length-1; ++i) {
      wktArray[i] += "]";
    }
    */
    
    var wktArray = new Array();
    var bkCount = 0;
    var obj = "";
    for (var i=0; i<wktTemp.length; ++i) {
      var token = wktTemp[i];
      for (var j=0; j<token.length; ++j) {
        if (token.charAt(j) == "[") ++bkCount;
        if (token.charAt(j) == "]") --bkCount;
      }
      obj += token;
      if (bkCount === 0) {
        wktArray.push(obj);
        obj = "";
      } else {
        obj += ",";
      }
    }
    
    //do something based on the type of the wktObject being parsed
    //add in variations in the spelling as required
    switch (wktObject) {
      case 'LOCAL_CS':
        this.projName = 'identity'
        this.localCS = true;
        this.srsCode = wktName;
        break;
      case 'GEOGCS':
        this.projName = 'longlat'
        this.geocsCode = wktName;
        if (!this.srsCode) this.srsCode = wktName;
        break;
      case 'PROJCS':
        this.srsCode = wktName;
        break;
      case 'GEOCCS':
        break;
      case 'PROJECTION':
        this.projName = Proj4js.wktProjections[wktName]
        break;
      case 'DATUM':
        this.datumName = wktName;
        break;
      case 'LOCAL_DATUM':
        this.datumCode = 'none';
        break;
      case 'SPHEROID':
        this.ellps = wktName;
        this.a = parseFloat(wktArray.shift());
        this.rf = parseFloat(wktArray.shift());
        break;
      case 'PRIMEM':
        this.from_greenwich = parseFloat(wktArray.shift()); //to radians?
        break;
      case 'UNIT':
        this.units = wktName;
        this.unitsPerMeter = parseFloat(wktArray.shift());
        break;
      case 'PARAMETER':
        var name = wktName.toLowerCase();
        var value = parseFloat(wktArray.shift());
        //there may be many variations on the wktName values, add in case
        //statements as required
        switch (name) {
          case 'false_easting':
            this.x0 = value;
            break;
          case 'false_northing':
            this.y0 = value;
            break;
          case 'scale_factor':
            this.k0 = value;
            break;
          case 'central_meridian':
            this.long0 = value*Proj4js.common.D2R;
            break;
          case 'latitude_of_origin':
            this.lat0 = value*Proj4js.common.D2R;
            break;
          case 'more_here':
            break;
          default:
            break;
        }
        break;
      case 'TOWGS84':
        this.datum_params = wktArray;
        break;
      //DGR 2010-11-12: AXIS
      case 'AXIS':
        var name= wktName.toLowerCase();
        var value= wktArray.shift();
        switch (value) {
          case 'EAST' : value= 'e'; break;
          case 'WEST' : value= 'w'; break;
          case 'NORTH': value= 'n'; break;
          case 'SOUTH': value= 's'; break;
          case 'UP'   : value= 'u'; break;
          case 'DOWN' : value= 'd'; break;
          case 'OTHER':
          default     : value= ' '; break;//FIXME
        }
        if (!this.axis) { this.axis= "enu"; }
        switch(name) {
          case 'X': this.axis=                         value + this.axis.substr(1,2); break;
          case 'Y': this.axis= this.axis.substr(0,1) + value + this.axis.substr(2,1); break;
          case 'Z': this.axis= this.axis.substr(0,2) + value                        ; break;
          default : break;
        }
      case 'MORE_HERE':
        break;
      default:
        break;
    }
    for (var i=0; i<wktArray.length; ++i) {
      this.parseWKT(wktArray[i]);
    }
 },

/**
 * Function: parseDefs
 * Parses the PROJ.4 initialization string and sets the associated properties.
 *
 */
  parseDefs: function() {
      this.defData = Proj4js.defs[this.srsCode];
      var paramName, paramVal;
      if (!this.defData) {
        return;
      }
      var paramArray=this.defData.split("+");

      for (var prop=0; prop<paramArray.length; prop++) {
          var property = paramArray[prop].split("=");
          paramName = property[0].toLowerCase();
          paramVal = property[1];

          switch (paramName.replace(/\s/gi,"")) {  // trim out spaces
              case "": break;   // throw away nameless parameter
              case "title":  this.title = paramVal; break;
              case "proj":   this.projName =  paramVal.replace(/\s/gi,""); break;
              case "units":  this.units = paramVal.replace(/\s/gi,""); break;
              case "datum":  this.datumCode = paramVal.replace(/\s/gi,""); break;
              case "nadgrids": this.nagrids = paramVal.replace(/\s/gi,""); break;
              case "ellps":  this.ellps = paramVal.replace(/\s/gi,""); break;
              case "a":      this.a =  parseFloat(paramVal); break;  // semi-major radius
              case "b":      this.b =  parseFloat(paramVal); break;  // semi-minor radius
              // DGR 2007-11-20
              case "rf":     this.rf = parseFloat(paramVal); break; // inverse flattening rf= a/(a-b)
              case "lat_0":  this.lat0 = paramVal*Proj4js.common.D2R; break;        // phi0, central latitude
              case "lat_1":  this.lat1 = paramVal*Proj4js.common.D2R; break;        //standard parallel 1
              case "lat_2":  this.lat2 = paramVal*Proj4js.common.D2R; break;        //standard parallel 2
              case "lat_ts": this.lat_ts = paramVal*Proj4js.common.D2R; break;      // used in merc and eqc
              case "lon_0":  this.long0 = paramVal*Proj4js.common.D2R; break;       // lam0, central longitude
              case "alpha":  this.alpha =  parseFloat(paramVal)*Proj4js.common.D2R; break;  //for somerc projection
              case "lonc":   this.longc = paramVal*Proj4js.common.D2R; break;       //for somerc projection
              case "x_0":    this.x0 = parseFloat(paramVal); break;  // false easting
              case "y_0":    this.y0 = parseFloat(paramVal); break;  // false northing
              case "k_0":    this.k0 = parseFloat(paramVal); break;  // projection scale factor
              case "k":      this.k0 = parseFloat(paramVal); break;  // both forms returned
              case "r_a":    this.R_A = true; break;                 // sphere--area of ellipsoid
              case "zone":   this.zone = parseInt(paramVal); break;  // UTM Zone
              case "south":   this.utmSouth = true; break;  // UTM north/south
              case "towgs84":this.datum_params = paramVal.split(","); break;
              case "to_meter": this.to_meter = parseFloat(paramVal); break; // cartesian scaling
              case "from_greenwich": this.from_greenwich = paramVal*Proj4js.common.D2R; break;
              // DGR 2008-07-09 : if pm is not a well-known prime meridian take
              // the value instead of 0.0, then convert to radians
              case "pm":     paramVal = paramVal.replace(/\s/gi,"");
                             this.from_greenwich = Proj4js.PrimeMeridian[paramVal] ?
                                Proj4js.PrimeMeridian[paramVal] : parseFloat(paramVal);
                             this.from_greenwich *= Proj4js.common.D2R; 
                             break;
              // DGR 2010-11-12: axis
              case "axis":   paramVal = paramVal.replace(/\s/gi,"");
                             var legalAxis= "ewnsud";
                             if (paramVal.length==3 &&
                                 legalAxis.indexOf(paramVal.substr(0,1))!=-1 &&
                                 legalAxis.indexOf(paramVal.substr(1,1))!=-1 &&
                                 legalAxis.indexOf(paramVal.substr(2,1))!=-1) {
                                this.axis= paramVal;
                             } //FIXME: be silent ?
                             break
              case "no_defs": break; 
              default: //alert("Unrecognized parameter: " + paramName);
          } // switch()
      } // for paramArray
      this.deriveConstants();
  },

/**
 * Function: deriveConstants
 * Sets several derived constant values and initialization of datum and ellipse
 *     parameters.
 *
 */
  deriveConstants: function() {
      if (this.nagrids == '@null') this.datumCode = 'none';
      if (this.datumCode && this.datumCode != 'none') {
        var datumDef = Proj4js.Datum[this.datumCode];
        if (datumDef) {
          this.datum_params = datumDef.towgs84 ? datumDef.towgs84.split(',') : null;
          this.ellps = datumDef.ellipse;
          this.datumName = datumDef.datumName ? datumDef.datumName : this.datumCode;
        }
      }
      if (!this.a) {    // do we have an ellipsoid?
          var ellipse = Proj4js.Ellipsoid[this.ellps] ? Proj4js.Ellipsoid[this.ellps] : Proj4js.Ellipsoid['WGS84'];
          Proj4js.extend(this, ellipse);
      }
      if (this.rf && !this.b) this.b = (1.0 - 1.0/this.rf) * this.a;
      if (Math.abs(this.a - this.b)<Proj4js.common.EPSLN) {
        this.sphere = true;
        this.b= this.a;
      }
      this.a2 = this.a * this.a;          // used in geocentric
      this.b2 = this.b * this.b;          // used in geocentric
      this.es = (this.a2-this.b2)/this.a2;  // e ^ 2
      this.e = Math.sqrt(this.es);        // eccentricity
      if (this.R_A) {
        this.a *= 1. - this.es * (Proj4js.common.SIXTH + this.es * (Proj4js.common.RA4 + this.es * Proj4js.common.RA6));
        this.a2 = this.a * this.a;
        this.b2 = this.b * this.b;
        this.es = 0.;
      }
      this.ep2=(this.a2-this.b2)/this.b2; // used in geocentric
      if (!this.k0) this.k0 = 1.0;    //default value
      //DGR 2010-11-12: axis
      if (!this.axis) { this.axis= "enu"; }

      this.datum = new Proj4js.datum(this);
  }
});

Proj4js.Proj.longlat = {
  init: function() {
    //no-op for longlat
  },
  forward: function(pt) {
    //identity transform
    return pt;
  },
  inverse: function(pt) {
    //identity transform
    return pt;
  }
};
Proj4js.Proj.identity = Proj4js.Proj.longlat;

/**
  Proj4js.defs is a collection of coordinate system definition objects in the 
  PROJ.4 command line format.
  Generally a def is added by means of a separate .js file for example:

    <SCRIPT type="text/javascript" src="defs/EPSG26912.js"></SCRIPT>

  def is a CS definition in PROJ.4 WKT format, for example:
    +proj="tmerc"   //longlat, etc.
    +a=majorRadius
    +b=minorRadius
    +lat0=somenumber
    +long=somenumber
*/
Proj4js.defs = {
  // These are so widely used, we'll go ahead and throw them in
  // without requiring a separate .js file
  'WGS84': "+title=long/lat:WGS84 +proj=longlat +ellps=WGS84 +datum=WGS84 +units=degrees",
  'EPSG:4326': "+title=long/lat:WGS84 +proj=longlat +a=6378137.0 +b=6356752.31424518 +ellps=WGS84 +datum=WGS84 +units=degrees",
  'EPSG:4269': "+title=long/lat:NAD83 +proj=longlat +a=6378137.0 +b=6356752.31414036 +ellps=GRS80 +datum=NAD83 +units=degrees",
  'EPSG:3785': "+title= Google Mercator +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs"
};
Proj4js.defs['GOOGLE'] = Proj4js.defs['EPSG:3785'];
Proj4js.defs['EPSG:900913'] = Proj4js.defs['EPSG:3785'];
Proj4js.defs['EPSG:102113'] = Proj4js.defs['EPSG:3785'];

Proj4js.common = {
  PI : 3.141592653589793238, //Math.PI,
  HALF_PI : 1.570796326794896619, //Math.PI*0.5,
  TWO_PI : 6.283185307179586477, //Math.PI*2,
  FORTPI : 0.78539816339744833,
  R2D : 57.29577951308232088,
  D2R : 0.01745329251994329577,
  SEC_TO_RAD : 4.84813681109535993589914102357e-6, /* SEC_TO_RAD = Pi/180/3600 */
  EPSLN : 1.0e-10,
  MAX_ITER : 20,
  // following constants from geocent.c
  COS_67P5 : 0.38268343236508977,  /* cosine of 67.5 degrees */
  AD_C : 1.0026000,                /* Toms region 1 constant */

  /* datum_type values */
  PJD_UNKNOWN  : 0,
  PJD_3PARAM   : 1,
  PJD_7PARAM   : 2,
  PJD_GRIDSHIFT: 3,
  PJD_WGS84    : 4,   // WGS84 or equivalent
  PJD_NODATUM  : 5,   // WGS84 or equivalent
  SRS_WGS84_SEMIMAJOR : 6378137.0,  // only used in grid shift transforms

  // ellipoid pj_set_ell.c
  SIXTH : .1666666666666666667, /* 1/6 */
  RA4   : .04722222222222222222, /* 17/360 */
  RA6   : .02215608465608465608, /* 67/3024 */
  RV4   : .06944444444444444444, /* 5/72 */
  RV6   : .04243827160493827160, /* 55/1296 */

// Function to compute the constant small m which is the radius of
//   a parallel of latitude, phi, divided by the semimajor axis.
// -----------------------------------------------------------------
  msfnz : function(eccent, sinphi, cosphi) {
      var con = eccent * sinphi;
      return cosphi/(Math.sqrt(1.0 - con * con));
  },

// Function to compute the constant small t for use in the forward
//   computations in the Lambert Conformal Conic and the Polar
//   Stereographic projections.
// -----------------------------------------------------------------
  tsfnz : function(eccent, phi, sinphi) {
    var con = eccent * sinphi;
    var com = .5 * eccent;
    con = Math.pow(((1.0 - con) / (1.0 + con)), com);
    return (Math.tan(.5 * (this.HALF_PI - phi))/con);
  },

// Function to compute the latitude angle, phi2, for the inverse of the
//   Lambert Conformal Conic and Polar Stereographic projections.
// ----------------------------------------------------------------
  phi2z : function(eccent, ts) {
    var eccnth = .5 * eccent;
    var con, dphi;
    var phi = this.HALF_PI - 2 * Math.atan(ts);
    for (var i = 0; i <= 15; i++) {
      con = eccent * Math.sin(phi);
      dphi = this.HALF_PI - 2 * Math.atan(ts *(Math.pow(((1.0 - con)/(1.0 + con)),eccnth))) - phi;
      phi += dphi;
      if (Math.abs(dphi) <= .0000000001) return phi;
    }
    alert("phi2z has NoConvergence");
    return (-9999);
  },

/* Function to compute constant small q which is the radius of a 
   parallel of latitude, phi, divided by the semimajor axis. 
------------------------------------------------------------*/
  qsfnz : function(eccent,sinphi) {
    var con;
    if (eccent > 1.0e-7) {
      con = eccent * sinphi;
      return (( 1.0- eccent * eccent) * (sinphi /(1.0 - con * con) - (.5/eccent)*Math.log((1.0 - con)/(1.0 + con))));
    } else {
      return(2.0 * sinphi);
    }
  },

/* Function to eliminate roundoff errors in asin
----------------------------------------------*/
  asinz : function(x) {
    if (Math.abs(x)>1.0) {
      x=(x>1.0)?1.0:-1.0;
    }
    return Math.asin(x);
  },

// following functions from gctpc cproj.c for transverse mercator projections
  e0fn : function(x) {return(1.0-0.25*x*(1.0+x/16.0*(3.0+1.25*x)));},
  e1fn : function(x) {return(0.375*x*(1.0+0.25*x*(1.0+0.46875*x)));},
  e2fn : function(x) {return(0.05859375*x*x*(1.0+0.75*x));},
  e3fn : function(x) {return(x*x*x*(35.0/3072.0));},
  mlfn : function(e0,e1,e2,e3,phi) {return(e0*phi-e1*Math.sin(2.0*phi)+e2*Math.sin(4.0*phi)-e3*Math.sin(6.0*phi));},

  srat : function(esinp, exp) {
    return(Math.pow((1.0-esinp)/(1.0+esinp), exp));
  },

// Function to return the sign of an argument
  sign : function(x) { if (x < 0.0) return(-1); else return(1);},

// Function to adjust longitude to -180 to 180; input in radians
  adjust_lon : function(x) {
    x = (Math.abs(x) < this.PI) ? x: (x - (this.sign(x)*this.TWO_PI) );
    return x;
  },

// IGNF - DGR : algorithms used by IGN France

// Function to adjust latitude to -90 to 90; input in radians
  adjust_lat : function(x) {
    x= (Math.abs(x) < this.HALF_PI) ? x: (x - (this.sign(x)*this.PI) );
    return x;
  },

// Latitude Isometrique - close to tsfnz ...
  latiso : function(eccent, phi, sinphi) {
    if (Math.abs(phi) > this.HALF_PI) return +Number.NaN;
    if (phi==this.HALF_PI) return Number.POSITIVE_INFINITY;
    if (phi==-1.0*this.HALF_PI) return -1.0*Number.POSITIVE_INFINITY;

    var con= eccent*sinphi;
    return Math.log(Math.tan((this.HALF_PI+phi)/2.0))+eccent*Math.log((1.0-con)/(1.0+con))/2.0;
  },

  fL : function(x,L) {
    return 2.0*Math.atan(x*Math.exp(L)) - this.HALF_PI;
  },

// Inverse Latitude Isometrique - close to ph2z
  invlatiso : function(eccent, ts) {
    var phi= this.fL(1.0,ts);
    var Iphi= 0.0;
    var con= 0.0;
    do {
      Iphi= phi;
      con= eccent*Math.sin(Iphi);
      phi= this.fL(Math.exp(eccent*Math.log((1.0+con)/(1.0-con))/2.0),ts)
    } while (Math.abs(phi-Iphi)>1.0e-12);
    return phi;
  },

// Needed for Gauss Schreiber
// Original:  Denis Makarov (info@binarythings.com)
// Web Site:  http://www.binarythings.com
  sinh : function(x)
  {
    var r= Math.exp(x);
    r= (r-1.0/r)/2.0;
    return r;
  },

  cosh : function(x)
  {
    var r= Math.exp(x);
    r= (r+1.0/r)/2.0;
    return r;
  },

  tanh : function(x)
  {
    var r= Math.exp(x);
    r= (r-1.0/r)/(r+1.0/r);
    return r;
  },

  asinh : function(x)
  {
    var s= (x>= 0? 1.0:-1.0);
    return s*(Math.log( Math.abs(x) + Math.sqrt(x*x+1.0) ));
  },

  acosh : function(x)
  {
    return 2.0*Math.log(Math.sqrt((x+1.0)/2.0) + Math.sqrt((x-1.0)/2.0));
  },

  atanh : function(x)
  {
    return Math.log((x-1.0)/(x+1.0))/2.0;
  },

// Grande Normale
  gN : function(a,e,sinphi)
  {
    var temp= e*sinphi;
    return a/Math.sqrt(1.0 - temp*temp);
  }

};

/** datum object
*/
Proj4js.datum = Proj4js.Class({

  initialize : function(proj) {
    this.datum_type = Proj4js.common.PJD_WGS84;   //default setting
    if (proj.datumCode && proj.datumCode == 'none') {
      this.datum_type = Proj4js.common.PJD_NODATUM;
    }
    if (proj && proj.datum_params) {
      for (var i=0; i<proj.datum_params.length; i++) {
        proj.datum_params[i]=parseFloat(proj.datum_params[i]);
      }
      if (proj.datum_params[0] != 0 || proj.datum_params[1] != 0 || proj.datum_params[2] != 0 ) {
        this.datum_type = Proj4js.common.PJD_3PARAM;
      }
      if (proj.datum_params.length > 3) {
        if (proj.datum_params[3] != 0 || proj.datum_params[4] != 0 ||
            proj.datum_params[5] != 0 || proj.datum_params[6] != 0 ) {
          this.datum_type = Proj4js.common.PJD_7PARAM;
          proj.datum_params[3] *= Proj4js.common.SEC_TO_RAD;
          proj.datum_params[4] *= Proj4js.common.SEC_TO_RAD;
          proj.datum_params[5] *= Proj4js.common.SEC_TO_RAD;
          proj.datum_params[6] = (proj.datum_params[6]/1000000.0) + 1.0;
        }
      }
    }
    if (proj) {
      this.a = proj.a;    //datum object also uses these values
      this.b = proj.b;
      this.es = proj.es;
      this.ep2 = proj.ep2;
      this.datum_params = proj.datum_params;
    }
  },

  /****************************************************************/
  // cs_compare_datums()
  //   Returns 1 (TRUE) if the two datums match, otherwise 0 (FALSE).
  compare_datums : function( dest ) {
    if( this.datum_type != dest.datum_type ) {
      return false; // false, datums are not equal
    } else if( this.a != dest.a || Math.abs(this.es-dest.es) > 0.000000000050 ) {
      // the tolerence for es is to ensure that GRS80 and WGS84
      // are considered identical
      return false;
    } else if( this.datum_type == Proj4js.common.PJD_3PARAM ) {
      return (this.datum_params[0] == dest.datum_params[0]
              && this.datum_params[1] == dest.datum_params[1]
              && this.datum_params[2] == dest.datum_params[2]);
    } else if( this.datum_type == Proj4js.common.PJD_7PARAM ) {
      return (this.datum_params[0] == dest.datum_params[0]
              && this.datum_params[1] == dest.datum_params[1]
              && this.datum_params[2] == dest.datum_params[2]
              && this.datum_params[3] == dest.datum_params[3]
              && this.datum_params[4] == dest.datum_params[4]
              && this.datum_params[5] == dest.datum_params[5]
              && this.datum_params[6] == dest.datum_params[6]);
    } else if( this.datum_type == Proj4js.common.PJD_GRIDSHIFT ) {
      return strcmp( pj_param(this.params,"snadgrids").s,
                     pj_param(dest.params,"snadgrids").s ) == 0;
    } else {
      return true; // datums are equal
    }
  }, // cs_compare_datums()

  /*
   * The function Convert_Geodetic_To_Geocentric converts geodetic coordinates
   * (latitude, longitude, and height) to geocentric coordinates (X, Y, Z),
   * according to the current ellipsoid parameters.
   *
   *    Latitude  : Geodetic latitude in radians                     (input)
   *    Longitude : Geodetic longitude in radians                    (input)
   *    Height    : Geodetic height, in meters                       (input)
   *    X         : Calculated Geocentric X coordinate, in meters    (output)
   *    Y         : Calculated Geocentric Y coordinate, in meters    (output)
   *    Z         : Calculated Geocentric Z coordinate, in meters    (output)
   *
   */
  geodetic_to_geocentric : function(p) {
    var Longitude = p.x;
    var Latitude = p.y;
    var Height = p.z ? p.z : 0;   //Z value not always supplied
    var X;  // output
    var Y;
    var Z;

    var Error_Code=0;  //  GEOCENT_NO_ERROR;
    var Rn;            /*  Earth radius at location  */
    var Sin_Lat;       /*  Math.sin(Latitude)  */
    var Sin2_Lat;      /*  Square of Math.sin(Latitude)  */
    var Cos_Lat;       /*  Math.cos(Latitude)  */

    /*
    ** Don't blow up if Latitude is just a little out of the value
    ** range as it may just be a rounding issue.  Also removed longitude
    ** test, it should be wrapped by Math.cos() and Math.sin().  NFW for PROJ.4, Sep/2001.
    */
    if( Latitude < -Proj4js.common.HALF_PI && Latitude > -1.001 * Proj4js.common.HALF_PI ) {
        Latitude = -Proj4js.common.HALF_PI;
    } else if( Latitude > Proj4js.common.HALF_PI && Latitude < 1.001 * Proj4js.common.HALF_PI ) {
        Latitude = Proj4js.common.HALF_PI;
    } else if ((Latitude < -Proj4js.common.HALF_PI) || (Latitude > Proj4js.common.HALF_PI)) {
      /* Latitude out of range */
      Proj4js.reportError('geocent:lat out of range:'+Latitude);
      return null;
    }

    if (Longitude > Proj4js.common.PI) Longitude -= (2*Proj4js.common.PI);
    Sin_Lat = Math.sin(Latitude);
    Cos_Lat = Math.cos(Latitude);
    Sin2_Lat = Sin_Lat * Sin_Lat;
    Rn = this.a / (Math.sqrt(1.0e0 - this.es * Sin2_Lat));
    X = (Rn + Height) * Cos_Lat * Math.cos(Longitude);
    Y = (Rn + Height) * Cos_Lat * Math.sin(Longitude);
    Z = ((Rn * (1 - this.es)) + Height) * Sin_Lat;

    p.x = X;
    p.y = Y;
    p.z = Z;
    return Error_Code;
  }, // cs_geodetic_to_geocentric()


  geocentric_to_geodetic : function (p) {
/* local defintions and variables */
/* end-criterium of loop, accuracy of sin(Latitude) */
var genau = 1.E-12;
var genau2 = (genau*genau);
var maxiter = 30;

    var P;        /* distance between semi-minor axis and location */
    var RR;       /* distance between center and location */
    var CT;       /* sin of geocentric latitude */
    var ST;       /* cos of geocentric latitude */
    var RX;
    var RK;
    var RN;       /* Earth radius at location */
    var CPHI0;    /* cos of start or old geodetic latitude in iterations */
    var SPHI0;    /* sin of start or old geodetic latitude in iterations */
    var CPHI;     /* cos of searched geodetic latitude */
    var SPHI;     /* sin of searched geodetic latitude */
    var SDPHI;    /* end-criterium: addition-theorem of sin(Latitude(iter)-Latitude(iter-1)) */
    var At_Pole;     /* indicates location is in polar region */
    var iter;        /* # of continous iteration, max. 30 is always enough (s.a.) */

    var X = p.x;
    var Y = p.y;
    var Z = p.z ? p.z : 0.0;   //Z value not always supplied
    var Longitude;
    var Latitude;
    var Height;

    At_Pole = false;
    P = Math.sqrt(X*X+Y*Y);
    RR = Math.sqrt(X*X+Y*Y+Z*Z);

/*      special cases for latitude and longitude */
    if (P/this.a < genau) {

/*  special case, if P=0. (X=0., Y=0.) */
        At_Pole = true;
        Longitude = 0.0;

/*  if (X,Y,Z)=(0.,0.,0.) then Height becomes semi-minor axis
 *  of ellipsoid (=center of mass), Latitude becomes PI/2 */
        if (RR/this.a < genau) {
            Latitude = Proj4js.common.HALF_PI;
            Height   = -this.b;
            return;
        }
    } else {
/*  ellipsoidal (geodetic) longitude
 *  interval: -PI < Longitude <= +PI */
        Longitude=Math.atan2(Y,X);
    }

/* --------------------------------------------------------------
 * Following iterative algorithm was developped by
 * "Institut fï¿œr Erdmessung", University of Hannover, July 1988.
 * Internet: www.ife.uni-hannover.de
 * Iterative computation of CPHI,SPHI and Height.
 * Iteration of CPHI and SPHI to 10**-12 radian resp.
 * 2*10**-7 arcsec.
 * --------------------------------------------------------------
 */
    CT = Z/RR;
    ST = P/RR;
    RX = 1.0/Math.sqrt(1.0-this.es*(2.0-this.es)*ST*ST);
    CPHI0 = ST*(1.0-this.es)*RX;
    SPHI0 = CT*RX;
    iter = 0;

/* loop to find sin(Latitude) resp. Latitude
 * until |sin(Latitude(iter)-Latitude(iter-1))| < genau */
    do
    {
        iter++;
        RN = this.a/Math.sqrt(1.0-this.es*SPHI0*SPHI0);

/*  ellipsoidal (geodetic) height */
        Height = P*CPHI0+Z*SPHI0-RN*(1.0-this.es*SPHI0*SPHI0);

        RK = this.es*RN/(RN+Height);
        RX = 1.0/Math.sqrt(1.0-RK*(2.0-RK)*ST*ST);
        CPHI = ST*(1.0-RK)*RX;
        SPHI = CT*RX;
        SDPHI = SPHI*CPHI0-CPHI*SPHI0;
        CPHI0 = CPHI;
        SPHI0 = SPHI;
    }
    while (SDPHI*SDPHI > genau2 && iter < maxiter);

/*      ellipsoidal (geodetic) latitude */
    Latitude=Math.atan(SPHI/Math.abs(CPHI));

    p.x = Longitude;
    p.y = Latitude;
    p.z = Height;
    return p;
  }, // cs_geocentric_to_geodetic()

  /** Convert_Geocentric_To_Geodetic
   * The method used here is derived from 'An Improved Algorithm for
   * Geocentric to Geodetic Coordinate Conversion', by Ralph Toms, Feb 1996
   */
  geocentric_to_geodetic_noniter : function (p) {
    var X = p.x;
    var Y = p.y;
    var Z = p.z ? p.z : 0;   //Z value not always supplied
    var Longitude;
    var Latitude;
    var Height;

    var W;        /* distance from Z axis */
    var W2;       /* square of distance from Z axis */
    var T0;       /* initial estimate of vertical component */
    var T1;       /* corrected estimate of vertical component */
    var S0;       /* initial estimate of horizontal component */
    var S1;       /* corrected estimate of horizontal component */
    var Sin_B0;   /* Math.sin(B0), B0 is estimate of Bowring aux variable */
    var Sin3_B0;  /* cube of Math.sin(B0) */
    var Cos_B0;   /* Math.cos(B0) */
    var Sin_p1;   /* Math.sin(phi1), phi1 is estimated latitude */
    var Cos_p1;   /* Math.cos(phi1) */
    var Rn;       /* Earth radius at location */
    var Sum;      /* numerator of Math.cos(phi1) */
    var At_Pole;  /* indicates location is in polar region */

    X = parseFloat(X);  // cast from string to float
    Y = parseFloat(Y);
    Z = parseFloat(Z);

    At_Pole = false;
    if (X != 0.0)
    {
        Longitude = Math.atan2(Y,X);
    }
    else
    {
        if (Y > 0)
        {
            Longitude = Proj4js.common.HALF_PI;
        }
        else if (Y < 0)
        {
            Longitude = -Proj4js.common.HALF_PI;
        }
        else
        {
            At_Pole = true;
            Longitude = 0.0;
            if (Z > 0.0)
            {  /* north pole */
                Latitude = Proj4js.common.HALF_PI;
            }
            else if (Z < 0.0)
            {  /* south pole */
                Latitude = -Proj4js.common.HALF_PI;
            }
            else
            {  /* center of earth */
                Latitude = Proj4js.common.HALF_PI;
                Height = -this.b;
                return;
            }
        }
    }
    W2 = X*X + Y*Y;
    W = Math.sqrt(W2);
    T0 = Z * Proj4js.common.AD_C;
    S0 = Math.sqrt(T0 * T0 + W2);
    Sin_B0 = T0 / S0;
    Cos_B0 = W / S0;
    Sin3_B0 = Sin_B0 * Sin_B0 * Sin_B0;
    T1 = Z + this.b * this.ep2 * Sin3_B0;
    Sum = W - this.a * this.es * Cos_B0 * Cos_B0 * Cos_B0;
    S1 = Math.sqrt(T1*T1 + Sum * Sum);
    Sin_p1 = T1 / S1;
    Cos_p1 = Sum / S1;
    Rn = this.a / Math.sqrt(1.0 - this.es * Sin_p1 * Sin_p1);
    if (Cos_p1 >= Proj4js.common.COS_67P5)
    {
        Height = W / Cos_p1 - Rn;
    }
    else if (Cos_p1 <= -Proj4js.common.COS_67P5)
    {
        Height = W / -Cos_p1 - Rn;
    }
    else
    {
        Height = Z / Sin_p1 + Rn * (this.es - 1.0);
    }
    if (At_Pole == false)
    {
        Latitude = Math.atan(Sin_p1 / Cos_p1);
    }

    p.x = Longitude;
    p.y = Latitude;
    p.z = Height;
    return p;
  }, // geocentric_to_geodetic_noniter()

  /****************************************************************/
  // pj_geocentic_to_wgs84( p )
  //  p = point to transform in geocentric coordinates (x,y,z)
  geocentric_to_wgs84 : function ( p ) {

    if( this.datum_type == Proj4js.common.PJD_3PARAM )
    {
      // if( x[io] == HUGE_VAL )
      //    continue;
      p.x += this.datum_params[0];
      p.y += this.datum_params[1];
      p.z += this.datum_params[2];

    }
    else if (this.datum_type == Proj4js.common.PJD_7PARAM)
    {
      var Dx_BF =this.datum_params[0];
      var Dy_BF =this.datum_params[1];
      var Dz_BF =this.datum_params[2];
      var Rx_BF =this.datum_params[3];
      var Ry_BF =this.datum_params[4];
      var Rz_BF =this.datum_params[5];
      var M_BF  =this.datum_params[6];
      // if( x[io] == HUGE_VAL )
      //    continue;
      var x_out = M_BF*(       p.x - Rz_BF*p.y + Ry_BF*p.z) + Dx_BF;
      var y_out = M_BF*( Rz_BF*p.x +       p.y - Rx_BF*p.z) + Dy_BF;
      var z_out = M_BF*(-Ry_BF*p.x + Rx_BF*p.y +       p.z) + Dz_BF;
      p.x = x_out;
      p.y = y_out;
      p.z = z_out;
    }
  }, // cs_geocentric_to_wgs84

  /****************************************************************/
  // pj_geocentic_from_wgs84()
  //  coordinate system definition,
  //  point to transform in geocentric coordinates (x,y,z)
  geocentric_from_wgs84 : function( p ) {

    if( this.datum_type == Proj4js.common.PJD_3PARAM )
    {
      //if( x[io] == HUGE_VAL )
      //    continue;
      p.x -= this.datum_params[0];
      p.y -= this.datum_params[1];
      p.z -= this.datum_params[2];

    }
    else if (this.datum_type == Proj4js.common.PJD_7PARAM)
    {
      var Dx_BF =this.datum_params[0];
      var Dy_BF =this.datum_params[1];
      var Dz_BF =this.datum_params[2];
      var Rx_BF =this.datum_params[3];
      var Ry_BF =this.datum_params[4];
      var Rz_BF =this.datum_params[5];
      var M_BF  =this.datum_params[6];
      var x_tmp = (p.x - Dx_BF) / M_BF;
      var y_tmp = (p.y - Dy_BF) / M_BF;
      var z_tmp = (p.z - Dz_BF) / M_BF;
      //if( x[io] == HUGE_VAL )
      //    continue;

      p.x =        x_tmp + Rz_BF*y_tmp - Ry_BF*z_tmp;
      p.y = -Rz_BF*x_tmp +       y_tmp + Rx_BF*z_tmp;
      p.z =  Ry_BF*x_tmp - Rx_BF*y_tmp +       z_tmp;
    } //cs_geocentric_from_wgs84()
  }
});

/** point object, nothing fancy, just allows values to be
    passed back and forth by reference rather than by value.
    Other point classes may be used as long as they have
    x and y properties, which will get modified in the transform method.
*/
Proj4js.Point = Proj4js.Class({

    /**
     * Constructor: Proj4js.Point
     *
     * Parameters:
     * - x {float} or {Array} either the first coordinates component or
     *     the full coordinates
     * - y {float} the second component
     * - z {float} the third component, optional.
     */
    initialize : function(x,y,z) {
      if (typeof x == 'object') {
        this.x = x[0];
        this.y = x[1];
        this.z = x[2] || 0.0;
      } else if (typeof x == 'string' && typeof y == 'undefined') {
        var coords = x.split(',');
        this.x = parseFloat(coords[0]);
        this.y = parseFloat(coords[1]);
        this.z = parseFloat(coords[2]) || 0.0;
      } else {
        this.x = x;
        this.y = y;
        this.z = z || 0.0;
      }
    },

    /**
     * APIMethod: clone
     * Build a copy of a Proj4js.Point object.
     *
     * Return:
     * {Proj4js}.Point the cloned point.
     */
    clone : function() {
      return new Proj4js.Point(this.x, this.y, this.z);
    },

    /**
     * APIMethod: toString
     * Return a readable string version of the point
     *
     * Return:
     * {String} String representation of Proj4js.Point object. 
     *           (ex. <i>"x=5,y=42"</i>)
     */
    toString : function() {
        return ("x=" + this.x + ",y=" + this.y);
    },

    /** 
     * APIMethod: toShortString
     * Return a short string version of the point.
     *
     * Return:
     * {String} Shortened String representation of Proj4js.Point object. 
     *         (ex. <i>"5, 42"</i>)
     */
    toShortString : function() {
        return (this.x + ", " + this.y);
    }
});

Proj4js.PrimeMeridian = {
    "greenwich": 0.0,               //"0dE",
    "lisbon":     -9.131906111111,   //"9d07'54.862\"W",
    "paris":       2.337229166667,   //"2d20'14.025\"E",
    "bogota":    -74.080916666667,  //"74d04'51.3\"W",
    "madrid":     -3.687938888889,  //"3d41'16.58\"W",
    "rome":       12.452333333333,  //"12d27'8.4\"E",
    "bern":        7.439583333333,  //"7d26'22.5\"E",
    "jakarta":   106.807719444444,  //"106d48'27.79\"E",
    "ferro":     -17.666666666667,  //"17d40'W",
    "brussels":    4.367975,        //"4d22'4.71\"E",
    "stockholm":  18.058277777778,  //"18d3'29.8\"E",
    "athens":     23.7163375,       //"23d42'58.815\"E",
    "oslo":       10.722916666667   //"10d43'22.5\"E"
};

Proj4js.Ellipsoid = {
  "MERIT": {a:6378137.0, rf:298.257, ellipseName:"MERIT 1983"},
  "SGS85": {a:6378136.0, rf:298.257, ellipseName:"Soviet Geodetic System 85"},
  "GRS80": {a:6378137.0, rf:298.257222101, ellipseName:"GRS 1980(IUGG, 1980)"},
  "IAU76": {a:6378140.0, rf:298.257, ellipseName:"IAU 1976"},
  "airy": {a:6377563.396, b:6356256.910, ellipseName:"Airy 1830"},
  "APL4.": {a:6378137, rf:298.25, ellipseName:"Appl. Physics. 1965"},
  "NWL9D": {a:6378145.0, rf:298.25, ellipseName:"Naval Weapons Lab., 1965"},
  "mod_airy": {a:6377340.189, b:6356034.446, ellipseName:"Modified Airy"},
  "andrae": {a:6377104.43, rf:300.0, ellipseName:"Andrae 1876 (Den., Iclnd.)"},
  "aust_SA": {a:6378160.0, rf:298.25, ellipseName:"Australian Natl & S. Amer. 1969"},
  "GRS67": {a:6378160.0, rf:298.2471674270, ellipseName:"GRS 67(IUGG 1967)"},
  "bessel": {a:6377397.155, rf:299.1528128, ellipseName:"Bessel 1841"},
  "bess_nam": {a:6377483.865, rf:299.1528128, ellipseName:"Bessel 1841 (Namibia)"},
  "clrk66": {a:6378206.4, b:6356583.8, ellipseName:"Clarke 1866"},
  "clrk80": {a:6378249.145, rf:293.4663, ellipseName:"Clarke 1880 mod."},
  "CPM": {a:6375738.7, rf:334.29, ellipseName:"Comm. des Poids et Mesures 1799"},
  "delmbr": {a:6376428.0, rf:311.5, ellipseName:"Delambre 1810 (Belgium)"},
  "engelis": {a:6378136.05, rf:298.2566, ellipseName:"Engelis 1985"},
  "evrst30": {a:6377276.345, rf:300.8017, ellipseName:"Everest 1830"},
  "evrst48": {a:6377304.063, rf:300.8017, ellipseName:"Everest 1948"},
  "evrst56": {a:6377301.243, rf:300.8017, ellipseName:"Everest 1956"},
  "evrst69": {a:6377295.664, rf:300.8017, ellipseName:"Everest 1969"},
  "evrstSS": {a:6377298.556, rf:300.8017, ellipseName:"Everest (Sabah & Sarawak)"},
  "fschr60": {a:6378166.0, rf:298.3, ellipseName:"Fischer (Mercury Datum) 1960"},
  "fschr60m": {a:6378155.0, rf:298.3, ellipseName:"Fischer 1960"},
  "fschr68": {a:6378150.0, rf:298.3, ellipseName:"Fischer 1968"},
  "helmert": {a:6378200.0, rf:298.3, ellipseName:"Helmert 1906"},
  "hough": {a:6378270.0, rf:297.0, ellipseName:"Hough"},
  "intl": {a:6378388.0, rf:297.0, ellipseName:"International 1909 (Hayford)"},
  "kaula": {a:6378163.0, rf:298.24, ellipseName:"Kaula 1961"},
  "lerch": {a:6378139.0, rf:298.257, ellipseName:"Lerch 1979"},
  "mprts": {a:6397300.0, rf:191.0, ellipseName:"Maupertius 1738"},
  "new_intl": {a:6378157.5, b:6356772.2, ellipseName:"New International 1967"},
  "plessis": {a:6376523.0, rf:6355863.0, ellipseName:"Plessis 1817 (France)"},
  "krass": {a:6378245.0, rf:298.3, ellipseName:"Krassovsky, 1942"},
  "SEasia": {a:6378155.0, b:6356773.3205, ellipseName:"Southeast Asia"},
  "walbeck": {a:6376896.0, b:6355834.8467, ellipseName:"Walbeck"},
  "WGS60": {a:6378165.0, rf:298.3, ellipseName:"WGS 60"},
  "WGS66": {a:6378145.0, rf:298.25, ellipseName:"WGS 66"},
  "WGS72": {a:6378135.0, rf:298.26, ellipseName:"WGS 72"},
  "WGS84": {a:6378137.0, rf:298.257223563, ellipseName:"WGS 84"},
  "sphere": {a:6370997.0, b:6370997.0, ellipseName:"Normal Sphere (r=6370997)"}
};

Proj4js.Datum = {
  "WGS84": {towgs84: "0,0,0", ellipse: "WGS84", datumName: "WGS84"},
  "GGRS87": {towgs84: "-199.87,74.79,246.62", ellipse: "GRS80", datumName: "Greek_Geodetic_Reference_System_1987"},
  "NAD83": {towgs84: "0,0,0", ellipse: "GRS80", datumName: "North_American_Datum_1983"},
  "NAD27": {nadgrids: "@conus,@alaska,@ntv2_0.gsb,@ntv1_can.dat", ellipse: "clrk66", datumName: "North_American_Datum_1927"},
  "potsdam": {towgs84: "606.0,23.0,413.0", ellipse: "bessel", datumName: "Potsdam Rauenberg 1950 DHDN"},
  "carthage": {towgs84: "-263.0,6.0,431.0", ellipse: "clark80", datumName: "Carthage 1934 Tunisia"},
  "hermannskogel": {towgs84: "653.0,-212.0,449.0", ellipse: "bessel", datumName: "Hermannskogel"},
  "ire65": {towgs84: "482.530,-130.596,564.557,-1.042,-0.214,-0.631,8.15", ellipse: "mod_airy", datumName: "Ireland 1965"},
  "nzgd49": {towgs84: "59.47,-5.04,187.44,0.47,-0.1,1.024,-4.5993", ellipse: "intl", datumName: "New Zealand Geodetic Datum 1949"},
  "OSGB36": {towgs84: "446.448,-125.157,542.060,0.1502,0.2470,0.8421,-20.4894", ellipse: "airy", datumName: "Airy 1830"}
};

Proj4js.WGS84 = new Proj4js.Proj('WGS84');
Proj4js.Datum['OSB36'] = Proj4js.Datum['OSGB36']; //as returned from spatialreference.org

//lookup table to go from the projection name in WKT to the Proj4js projection name
//build this out as required
Proj4js.wktProjections = {
  "Lambert Tangential Conformal Conic Projection": "lcc",
  "Mercator": "merc",
  "Popular Visualisation Pseudo Mercator": "merc",
  "Transverse_Mercator": "tmerc",
  "Transverse Mercator": "tmerc",
  "Lambert Azimuthal Equal Area": "laea",
  "Universal Transverse Mercator System": "utm"
};