From b67feb4590412392fdefd63013c3789c840c9d87 Mon Sep 17 00:00:00 2001
From: qnstie <pawel@kunstman.net>
Date: Wed, 17 Jul 2013 13:26:59 +0200
Subject: [PATCH] Geodesic extension for Leaflet from
 https://github.com/Fragger/Leaflet.Geodesic

---
 external/L.Geodesic.js | 128 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 external/L.Geodesic.js

diff --git a/external/L.Geodesic.js b/external/L.Geodesic.js
new file mode 100644
index 00000000..8f2a5fe3
--- /dev/null
+++ b/external/L.Geodesic.js
@@ -0,0 +1,128 @@
+/*
+Geodesic extension to Leaflet library, by Fragger
+https://github.com/Fragger/Leaflet.Geodesic
+Version from master branch, dated Apr 26, 2013
+*/
+(function () {
+  function geodesicPoly(Klass, fill) {
+    return Klass.extend({
+      initialize: function (latlngs, options) {
+        Klass.prototype.initialize.call(this, L.geodesicConvertLines(latlngs, fill), options);
+        this._latlngsinit = this._convertLatLngs(latlngs);
+      },
+      getLatLngs: function () {
+        return this._latlngsinit;
+      },
+      setLatLngs: function (latlngs) {
+        this._latlngsinit = this._convertLatLngs(latlngs);
+        this._latlngs = this._convertLatLngs(L.geodesicConvertLines(this._latlngsinit, fill));
+        return this.redraw();
+      },
+      addLatLng: function (latlng) {
+        this._latlngsinit.push(L.latLng(latlng));
+        this._latlngs = this._convertLatLngs(L.geodesicConvertLines(this._latlngsinit, fill));
+        return this.redraw();
+      },
+      spliceLatLngs: function () { // (Number index, Number howMany)
+        var removed = [].splice.apply(this._latlngsinit, arguments);
+        this._convertLatLngs(this._latlngsinit);
+        this._latlngs = this._convertLatLngs(L.geodesicConvertLines(this._latlngsinit, fill));
+        this.redraw();
+        return removed;
+      }
+    });
+  }
+  
+  function geodesicConvertLine(startLatlng, endLatlng, convertedPoints) {
+    var i,
+      R = 6378137, // earth radius in meters (doesn't have to be exact)
+      maxlength = 5000, // meters before splitting
+      d2r = L.LatLng.DEG_TO_RAD,
+      r2d = L.LatLng.RAD_TO_DEG,
+      lat1, lat2, lng1, lng2, dLng, d, segments,
+      f, A, B, x, y, z, fLat, fLng;
+  
+    dLng = Math.abs(endLatlng.lng - startLatlng.lng) * d2r;
+    lat1 = startLatlng.lat * d2r;
+    lat2 = endLatlng.lat * d2r;
+    lng1 = startLatlng.lng * d2r;
+    lng2 = endLatlng.lng * d2r;
+
+    // http://en.wikipedia.org/wiki/Great-circle_distance
+    d = Math.atan2(Math.sqrt( Math.pow(Math.cos(lat2) * Math.sin(dLng), 2) + Math.pow(Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(dLng), 2) ), Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(dLng));
+
+    segments = Math.ceil(d * R / maxlength);
+    for (i = 1; i <= segments; i++) {
+      // http://williams.best.vwh.net/avform.htm#Intermediate
+      f = i / segments;
+      A = Math.sin((1-f)*d) / Math.sin(d);
+      B = Math.sin(f*d) / Math.sin(d);
+      x = A * Math.cos(lat1) * Math.cos(lng1) + B * Math.cos(lat2) * Math.cos(lng2);
+      y = A * Math.cos(lat1) * Math.sin(lng1) + B * Math.cos(lat2) * Math.sin(lng2);
+      z = A * Math.sin(lat1)                  + B * Math.sin(lat2);
+      fLat = r2d * Math.atan2(z, Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2)));
+      fLng = r2d * Math.atan2(y, x);
+
+      convertedPoints.push(L.latLng([fLat, fLng]));
+    }
+  }
+
+  L.geodesicConvertLines = function (latlngs, fill) {
+    var i, j, len, geodesiclatlngs = [];
+    for (i = 0, len = latlngs.length; i < len; i++) {
+      if (L.Util.isArray(latlngs[i]) && typeof latlngs[i][0] !== 'number') {
+        return;
+      }
+      latlngs[i] = L.latLng(latlngs[i]);
+    }
+    
+    if(!fill) {
+      geodesiclatlngs.push(latlngs[0]);
+    }
+    for (i = 0, len = latlngs.length - 1; i < len; i++) {
+      geodesicConvertLine(latlngs[i], latlngs[i+1], geodesiclatlngs);
+    }
+    if(fill) {
+      geodesicConvertLine(latlngs[len], latlngs[0], geodesiclatlngs);
+    }
+    return geodesiclatlngs;
+  }
+  
+  L.GeodesicPolyline = geodesicPoly(L.Polyline, 0);
+  L.GeodesicPolygon = geodesicPoly(L.Polygon, 1);
+
+  //L.GeodesicMultiPolyline = createMulti(L.GeodesicPolyline);
+  //L.GeodesicMultiPolygon = createMulti(L.GeodesicPolygon);
+
+  /*L.GeodesicMultiPolyline = L.MultiPolyline.extend({
+    initialize: function (latlngs, options) {
+      L.MultiPolyline.prototype.initialize.call(this, L.geodesicConvertLines(latlngs), options);
+    }
+  });*/
+
+  /*L.GeodesicMultiPolygon = L.MultiPolygon.extend({
+    initialize: function (latlngs, options) {
+      L.MultiPolygon.prototype.initialize.call(this, L.geodesicConvertLines(latlngs), options);
+    }
+  });*/
+
+
+  L.geodesicPolyline = function (latlngs, options) {
+    return new L.GeodesicPolyline(latlngs, options);
+  };
+
+  L.geodesicPolygon = function (latlngs, options) {
+    return new L.GeodesicPolygon(latlngs, options);
+  };
+  
+  /*
+  L.geodesicMultiPolyline = function (latlngs, options) {
+    return new L.GeodesicMultiPolyline(latlngs, options);
+  };
+
+  L.geodesicMultiPolygon = function (latlngs, options) {
+    return new L.GeodesicMultiPolygon(latlngs, options);
+  };
+
+  */
+}());