source: trunk/workshop-routing-foss4g/web/proj4js/lib/projCode/eqc.js @ 81

/* similar to equi.js FIXME proj4 uses eqc */
Proj4js.Proj.eqc = {
  init : function() {

      if(!this.x0) this.x0=0;
      if(!this.y0) this.y0=0;
      if(!this.lat0) this.lat0=0;
      if(!this.long0) this.long0=0;
      if(!this.lat_ts) this.lat_ts=0;
      if (!this.title) this.title = "Equidistant Cylindrical (Plate Carre)";

      this.rc= Math.cos(this.lat_ts);
    },


    // forward equations--mapping lat,long to x,y
    // -----------------------------------------------------------------
    forward : function(p) {

      var lon= p.x;
      var lat= p.y;

      var dlon = Proj4js.common.adjust_lon(lon - this.long0);
      var dlat = Proj4js.common.adjust_lat(lat - this.lat0 );
      p.x= this.x0 + (this.a*dlon*this.rc);
      p.y= this.y0 + (this.a*dlat        );
      return p;
    },

  // inverse equations--mapping x,y to lat/long
  // -----------------------------------------------------------------
  inverse : function(p) {

    var x= p.x;
    var y= p.y;

    p.x= Proj4js.common.adjust_lon(this.long0 + ((x - this.x0)/(this.a*this.rc)));
    p.y= Proj4js.common.adjust_lat(this.lat0  + ((y - this.y0)/(this.a        )));
    return p;
  }

};