131 lines
4.5 KiB
JavaScript

/*
Geodesic extension to Leaflet library, by Fragger
https://github.com/Fragger/Leaflet.Geodesic
Version from master branch, dated Apr 26, 2013
Modified by qnstie 2013-07-17 to maintain compatibility with Leaflet.draw
*/
(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);
return this.redraw();
},
addLatLng: function (latlng) {
this._latlngsinit.push(L.latLng(latlng));
return this.redraw();
},
spliceLatLngs: function () { // (Number index, Number howMany)
var removed = [].splice.apply(this._latlngsinit, arguments);
this._convertLatLngs(this._latlngsinit);
this.redraw();
return removed;
},
redraw: function() {
this._latlngs = this._convertLatLngs(L.geodesicConvertLines(this._latlngsinit, fill));
return Klass.prototype.redraw.call(this);
}
});
}
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);
};
*/
}());