leaflet.geodesic
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Add-on to draw geodesic lines with leaflet
840 lines (822 loc) • 39.2 kB
JavaScript
/*! Leaflet.Geodesic 2.5.2 - (c) Henry Thasler - https://github.com/henrythasler/Leaflet.Geodesic */
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }
var L = _interopDefault(require('leaflet'));
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/* global Reflect, Promise */
var extendStatics = function(d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
return extendStatics(d, b);
};
function __extends(d, b) {
extendStatics(d, b);
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
}
var __assign = function() {
__assign = Object.assign || function __assign(t) {
for (var s, i = 1, n = arguments.length; i < n; i++) {
s = arguments[i];
for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p)) t[p] = s[p];
}
return t;
};
return __assign.apply(this, arguments);
};
function __spreadArrays() {
for (var s = 0, i = 0, il = arguments.length; i < il; i++) s += arguments[i].length;
for (var r = Array(s), k = 0, i = 0; i < il; i++)
for (var a = arguments[i], j = 0, jl = a.length; j < jl; j++, k++)
r[k] = a[j];
return r;
}
var GeodesicCore = /** @class */ (function () {
function GeodesicCore(options) {
this.options = { wrap: true, steps: 3 };
this.ellipsoid = {
a: 6378137,
b: 6356752.3142,
f: 1 / 298.257223563
}; // WGS-84
this.options = __assign(__assign({}, this.options), options);
}
GeodesicCore.prototype.toRadians = function (degree) {
return degree * Math.PI / 180;
};
GeodesicCore.prototype.toDegrees = function (radians) {
return radians * 180 / Math.PI;
};
/**
* implements scientific modulus
* source: http://www.codeavenger.com/2017/05/19/JavaScript-Modulo-operation-and-the-Caesar-Cipher.html
* @param n
* @param p
* @return
*/
GeodesicCore.prototype.mod = function (n, p) {
var r = n % p;
return r < 0 ? r + p : r;
};
/**
* source: https://github.com/chrisveness/geodesy/blob/master/dms.js
* @param degrees arbitrary value
* @return degrees between 0..360
*/
GeodesicCore.prototype.wrap360 = function (degrees) {
if (0 <= degrees && degrees < 360) {
return degrees; // avoid rounding due to arithmetic ops if within range
}
else {
return this.mod(degrees, 360);
}
};
/**
* general wrap function with arbitrary max value
* @param degrees arbitrary value
* @param max
* @return degrees between `-max`..`+max`
*/
GeodesicCore.prototype.wrap = function (degrees, max) {
if (max === void 0) { max = 360; }
if (-max <= degrees && degrees <= max) {
return degrees;
}
else {
return this.mod((degrees + max), 2 * max) - max;
}
};
/**
* Vincenty direct calculation.
* based on the work of Chris Veness (https://github.com/chrisveness/geodesy)
* source: https://github.com/chrisveness/geodesy/blob/master/latlon-ellipsoidal-vincenty.js
*
* @param start starting point
* @param bearing initial bearing (in degrees)
* @param distance distance from starting point to calculate along given bearing in meters.
* @param maxInterations How many iterations can be made to reach the allowed deviation (`ε`), before an error will be thrown.
* @return Final point (destination point) and bearing (in degrees)
*/
GeodesicCore.prototype.direct = function (start, bearing, distance, maxInterations) {
if (maxInterations === void 0) { maxInterations = 100; }
var φ1 = this.toRadians(start.lat);
var λ1 = this.toRadians(start.lng);
var α1 = this.toRadians(bearing);
var s = distance;
var ε = Number.EPSILON * 1000;
var _a = this.ellipsoid, a = _a.a, b = _a.b, f = _a.f;
var sinα1 = Math.sin(α1);
var cosα1 = Math.cos(α1);
var tanU1 = (1 - f) * Math.tan(φ1), cosU1 = 1 / Math.sqrt((1 + tanU1 * tanU1)), sinU1 = tanU1 * cosU1;
var σ1 = Math.atan2(tanU1, cosα1); // σ1 = angular distance on the sphere from the equator to P1
var sinα = cosU1 * sinα1; // α = azimuth of the geodesic at the equator
var cosSqα = 1 - sinα * sinα;
var uSq = cosSqα * (a * a - b * b) / (b * b);
var A = 1 + uSq / 16384 * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
var B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
var σ = s / (b * A), sinσ = null, cosσ = null, Δσ = null; // σ = angular distance P₁ P₂ on the sphere
var cos2σₘ = null; // σₘ = angular distance on the sphere from the equator to the midpoint of the line
var σʹ = null, iterations = 0;
do {
cos2σₘ = Math.cos(2 * σ1 + σ);
sinσ = Math.sin(σ);
cosσ = Math.cos(σ);
Δσ = B * sinσ * (cos2σₘ + B / 4 * (cosσ * (-1 + 2 * cos2σₘ * cos2σₘ) -
B / 6 * cos2σₘ * (-3 + 4 * sinσ * sinσ) * (-3 + 4 * cos2σₘ * cos2σₘ)));
σʹ = σ;
σ = s / (b * A) + Δσ;
} while (Math.abs(σ - σʹ) > ε && ++iterations < maxInterations);
if (iterations >= maxInterations) {
throw new EvalError("Direct vincenty formula failed to converge after " + maxInterations + " iterations \n (start=" + start.lat + "/" + start.lng + "; bearing=" + bearing + "; distance=" + distance + ")"); // not possible?
}
var x = sinU1 * sinσ - cosU1 * cosσ * cosα1;
var φ2 = Math.atan2(sinU1 * cosσ + cosU1 * sinσ * cosα1, (1 - f) * Math.sqrt(sinα * sinα + x * x));
var λ = Math.atan2(sinσ * sinα1, cosU1 * cosσ - sinU1 * sinσ * cosα1);
var C = f / 16 * cosSqα * (4 + f * (4 - 3 * cosSqα));
var dL = λ - (1 - C) * f * sinα * (σ + C * sinσ * (cos2σₘ + C * cosσ * (-1 + 2 * cos2σₘ * cos2σₘ)));
var λ2 = λ1 + dL;
var α2 = Math.atan2(sinα, -x);
return {
lat: this.toDegrees(φ2),
lng: this.toDegrees(λ2),
bearing: this.wrap360(this.toDegrees(α2))
};
};
/**
* Vincenty inverse calculation.
* based on the work of Chris Veness (https://github.com/chrisveness/geodesy)
* source: https://github.com/chrisveness/geodesy/blob/master/latlon-ellipsoidal-vincenty.js
*
* @param start Latitude/longitude of starting point.
* @param dest Latitude/longitude of destination point.
* @return Object including distance, initialBearing, finalBearing.
*/
GeodesicCore.prototype.inverse = function (start, dest, maxInterations, mitigateConvergenceError) {
if (maxInterations === void 0) { maxInterations = 100; }
if (mitigateConvergenceError === void 0) { mitigateConvergenceError = true; }
var p1 = start, p2 = dest;
var φ1 = this.toRadians(p1.lat), λ1 = this.toRadians(p1.lng);
var φ2 = this.toRadians(p2.lat), λ2 = this.toRadians(p2.lng);
var π = Math.PI;
var ε = Number.EPSILON;
// allow alternative ellipsoid to be specified
var _a = this.ellipsoid, a = _a.a, b = _a.b, f = _a.f;
var dL = λ2 - λ1; // L = difference in longitude, U = reduced latitude, defined by tan U = (1-f)·tanφ.
var tanU1 = (1 - f) * Math.tan(φ1), cosU1 = 1 / Math.sqrt((1 + tanU1 * tanU1)), sinU1 = tanU1 * cosU1;
var tanU2 = (1 - f) * Math.tan(φ2), cosU2 = 1 / Math.sqrt((1 + tanU2 * tanU2)), sinU2 = tanU2 * cosU2;
var antipodal = Math.abs(dL) > π / 2 || Math.abs(φ2 - φ1) > π / 2;
var λ = dL, sinλ = null, cosλ = null; // λ = difference in longitude on an auxiliary sphere
var σ = antipodal ? π : 0, sinσ = 0, cosσ = antipodal ? -1 : 1, sinSqσ = null; // σ = angular distance P₁ P₂ on the sphere
var cos2σₘ = 1; // σₘ = angular distance on the sphere from the equator to the midpoint of the line
var sinα = null, cosSqα = 1; // α = azimuth of the geodesic at the equator
var C = null;
var λʹ = null, iterations = 0;
do {
sinλ = Math.sin(λ);
cosλ = Math.cos(λ);
sinSqσ = (cosU2 * sinλ) * (cosU2 * sinλ) + (cosU1 * sinU2 - sinU1 * cosU2 * cosλ) * (cosU1 * sinU2 - sinU1 * cosU2 * cosλ);
if (Math.abs(sinSqσ) < ε) {
break; // co-incident/antipodal points (falls back on λ/σ = L)
}
sinσ = Math.sqrt(sinSqσ);
cosσ = sinU1 * sinU2 + cosU1 * cosU2 * cosλ;
σ = Math.atan2(sinσ, cosσ);
sinα = cosU1 * cosU2 * sinλ / sinσ;
cosSqα = 1 - sinα * sinα;
cos2σₘ = (cosSqα !== 0) ? (cosσ - 2 * sinU1 * sinU2 / cosSqα) : 0; // on equatorial line cos²α = 0 (§6)
C = f / 16 * cosSqα * (4 + f * (4 - 3 * cosSqα));
λʹ = λ;
λ = dL + (1 - C) * f * sinα * (σ + C * sinσ * (cos2σₘ + C * cosσ * (-1 + 2 * cos2σₘ * cos2σₘ)));
var iterationCheck = antipodal ? Math.abs(λ) - π : Math.abs(λ);
if (iterationCheck > π) {
throw new EvalError('λ > π');
}
} while (Math.abs(λ - λʹ) > 1e-12 && ++iterations < maxInterations);
if (iterations >= maxInterations) {
if (mitigateConvergenceError) {
return this.inverse(start, new L.LatLng(dest.lat, dest.lng - 0.01), maxInterations, mitigateConvergenceError);
}
else {
throw new EvalError("Inverse vincenty formula failed to converge after " + maxInterations + " iterations \n (start=" + start.lat + "/" + start.lng + "; dest=" + dest.lat + "/" + dest.lng + ")");
}
}
var uSq = cosSqα * (a * a - b * b) / (b * b);
var A = 1 + uSq / 16384 * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
var B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
var Δσ = B * sinσ * (cos2σₘ + B / 4 * (cosσ * (-1 + 2 * cos2σₘ * cos2σₘ) -
B / 6 * cos2σₘ * (-3 + 4 * sinσ * sinσ) * (-3 + 4 * cos2σₘ * cos2σₘ)));
var s = b * A * (σ - Δσ); // s = length of the geodesic
// note special handling of exactly antipodal points where sin²σ = 0 (due to discontinuity
// atan2(0, 0) = 0 but atan2(this.ε, 0) = π/2 / 90°) - in which case bearing is always meridional,
// due north (or due south!)
// α = azimuths of the geodesic; α2 the direction P₁ P₂ produced
var α1 = Math.abs(sinSqσ) < ε ? 0 : Math.atan2(cosU2 * sinλ, cosU1 * sinU2 - sinU1 * cosU2 * cosλ);
var α2 = Math.abs(sinSqσ) < ε ? π : Math.atan2(cosU1 * sinλ, -sinU1 * cosU2 + cosU1 * sinU2 * cosλ);
return {
distance: s,
initialBearing: Math.abs(s) < ε ? NaN : this.wrap360(this.toDegrees(α1)),
finalBearing: Math.abs(s) < ε ? NaN : this.wrap360(this.toDegrees(α2))
};
};
/**
* Returns the point of intersection of two paths defined by position and bearing.
* This calculation uses a spherical model of the earth. This will lead to small errors compared to an ellipsiod model.
* based on the work of Chris Veness (https://github.com/chrisveness/geodesy)
* source: https://github.com/chrisveness/geodesy/blob/master/latlon-spherical.js
*
* @param firstPos 1st path: position and bearing
* @param firstBearing
* @param secondPos 2nd path: position and bearing
* @param secondBearing
*/
GeodesicCore.prototype.intersection = function (firstPos, firstBearing, secondPos, secondBearing) {
var φ1 = this.toRadians(firstPos.lat);
var λ1 = this.toRadians(firstPos.lng);
var φ2 = this.toRadians(secondPos.lat);
var λ2 = this.toRadians(secondPos.lng);
var θ13 = this.toRadians(firstBearing);
var θ23 = this.toRadians(secondBearing);
var Δφ = φ2 - φ1, Δλ = λ2 - λ1;
var π = Math.PI;
var ε = Number.EPSILON;
// angular distance p1-p2
var δ12 = 2 * Math.asin(Math.sqrt(Math.sin(Δφ / 2) * Math.sin(Δφ / 2)
+ Math.cos(φ1) * Math.cos(φ2) * Math.sin(Δλ / 2) * Math.sin(Δλ / 2)));
if (Math.abs(δ12) < ε) {
return firstPos; // coincident points
}
// initial/final bearings between points
var cosθa = (Math.sin(φ2) - Math.sin(φ1) * Math.cos(δ12)) / (Math.sin(δ12) * Math.cos(φ1));
var cosθb = (Math.sin(φ1) - Math.sin(φ2) * Math.cos(δ12)) / (Math.sin(δ12) * Math.cos(φ2));
var θa = Math.acos(Math.min(Math.max(cosθa, -1), 1)); // protect against rounding errors
var θb = Math.acos(Math.min(Math.max(cosθb, -1), 1)); // protect against rounding errors
var θ12 = Math.sin(λ2 - λ1) > 0 ? θa : 2 * π - θa;
var θ21 = Math.sin(λ2 - λ1) > 0 ? 2 * π - θb : θb;
var α1 = θ13 - θ12; // angle 2-1-3
var α2 = θ21 - θ23; // angle 1-2-3
if (Math.sin(α1) === 0 && Math.sin(α2) === 0) {
return null; // infinite intersections
}
if (Math.sin(α1) * Math.sin(α2) < 0) {
return null; // ambiguous intersection (antipodal?)
}
var cosα3 = -Math.cos(α1) * Math.cos(α2) + Math.sin(α1) * Math.sin(α2) * Math.cos(δ12);
var δ13 = Math.atan2(Math.sin(δ12) * Math.sin(α1) * Math.sin(α2), Math.cos(α2) + Math.cos(α1) * cosα3);
var φ3 = Math.asin(Math.min(Math.max(Math.sin(φ1) * Math.cos(δ13) + Math.cos(φ1) * Math.sin(δ13) * Math.cos(θ13), -1), 1));
var Δλ13 = Math.atan2(Math.sin(θ13) * Math.sin(δ13) * Math.cos(φ1), Math.cos(δ13) - Math.sin(φ1) * Math.sin(φ3));
var λ3 = λ1 + Δλ13;
return new L.LatLng(this.toDegrees(φ3), this.toDegrees(λ3));
};
GeodesicCore.prototype.midpoint = function (start, dest) {
// φm = atan2( sinφ1 + sinφ2, √( (cosφ1 + cosφ2⋅cosΔλ)² + cos²φ2⋅sin²Δλ ) )
// λm = λ1 + atan2(cosφ2⋅sinΔλ, cosφ1 + cosφ2⋅cosΔλ)
// midpoint is sum of vectors to two points: mathforum.org/library/drmath/view/51822.html
var φ1 = this.toRadians(start.lat);
var λ1 = this.toRadians(start.lng);
var φ2 = this.toRadians(dest.lat);
var Δλ = this.toRadians(dest.lng - start.lng);
// get cartesian coordinates for the two points
var A = { x: Math.cos(φ1), y: 0, z: Math.sin(φ1) }; // place point A on prime meridian y=0
var B = { x: Math.cos(φ2) * Math.cos(Δλ), y: Math.cos(φ2) * Math.sin(Δλ), z: Math.sin(φ2) };
// vector to midpoint is sum of vectors to two points (no need to normalise)
var C = { x: A.x + B.x, y: A.y + B.y, z: A.z + B.z };
var φm = Math.atan2(C.z, Math.sqrt(C.x * C.x + C.y * C.y));
var λm = λ1 + Math.atan2(C.y, C.x);
return new L.LatLng(this.toDegrees(φm), this.toDegrees(λm));
};
return GeodesicCore;
}());
var GeodesicGeometry = /** @class */ (function () {
function GeodesicGeometry(options) {
this.geodesic = new GeodesicCore();
this.steps = (options && options.steps !== undefined) ? options.steps : 3;
}
/**
* A geodesic line between `start` and `dest` is created with this recursive function.
* It calculates the geodesic midpoint between `start` and `dest` and uses this midpoint to call itself again (twice!).
* The results are then merged into one continuous linestring.
*
* The number of resulting vertices (incl. `start` and `dest`) depends on the initial value for `iterations`
* and can be calculated with: vertices == 1 + 2 ** (initialIterations + 1)
*
* As this is an exponential function, be extra careful to limit the initial value for `iterations` (8 results in 513 vertices).
*
* @param start start position
* @param dest destination
* @param iterations
* @return resulting linestring
*/
GeodesicGeometry.prototype.recursiveMidpoint = function (start, dest, iterations) {
var geom = [start, dest];
var midpoint = this.geodesic.midpoint(start, dest);
if (iterations > 0) {
geom.splice.apply(geom, __spreadArrays([0, 1], this.recursiveMidpoint(start, midpoint, iterations - 1)));
geom.splice.apply(geom, __spreadArrays([geom.length - 2, 2], this.recursiveMidpoint(midpoint, dest, iterations - 1)));
}
else {
geom.splice(1, 0, midpoint);
}
return geom;
};
/**
* This is the wrapper-function to generate a geodesic line. It's just for future backwards-compatibility
* if there is another algorithm used to create the actual line.
*
* The `steps`-property is used to define the number of resulting vertices of the linestring: vertices == 1 + 2 ** (steps + 1)
* The value for `steps` is currently limited to 8 (513 vertices) for performance reasons until another algorithm is found.
*
* @param start start position
* @param dest destination
* @return resulting linestring
*/
GeodesicGeometry.prototype.line = function (start, dest) {
return this.recursiveMidpoint(start, dest, Math.min(8, this.steps));
};
GeodesicGeometry.prototype.multiLineString = function (latlngs) {
var _this = this;
var multiLineString = [];
latlngs.forEach(function (linestring) {
var segment = [];
for (var j = 1; j < linestring.length; j++) {
segment.splice.apply(segment, __spreadArrays([segment.length - 1, 1], _this.line(linestring[j - 1], linestring[j])));
}
multiLineString.push(segment);
});
return multiLineString;
};
GeodesicGeometry.prototype.lineString = function (latlngs) {
return this.multiLineString([latlngs])[0];
};
/**
*
* Is much (10x) faster than the previous implementation:
*
* ```
* Benchmark (no split): splitLine x 459,044 ops/sec ±0.53% (95 runs sampled)
* Benchmark (split): splitLine x 42,999 ops/sec ±0.51% (97 runs sampled)
* ```
*
* @param startPosition
* @param destPosition
*/
GeodesicGeometry.prototype.splitLine = function (startPosition, destPosition) {
var antimeridianWest = {
point: new L.LatLng(89.9, -180.0000001),
bearing: 180
};
var antimeridianEast = {
point: new L.LatLng(89.9, 180.0000001),
bearing: 180
};
// make a copy to work with
var start = new L.LatLng(startPosition.lat, startPosition.lng);
var dest = new L.LatLng(destPosition.lat, destPosition.lng);
start.lng = this.geodesic.wrap(start.lng, 360);
dest.lng = this.geodesic.wrap(dest.lng, 360);
if ((dest.lng - start.lng) > 180) {
dest.lng = dest.lng - 360;
}
else if ((dest.lng - start.lng) < -180) {
dest.lng = dest.lng + 360;
}
var result = [[new L.LatLng(start.lat, this.geodesic.wrap(start.lng, 180)), new L.LatLng(dest.lat, this.geodesic.wrap(dest.lng, 180))]];
// crossing antimeridian from "this" side?
if ((start.lng >= -180) && (start.lng <= 180)) {
// crossing the "western" antimeridian
if (dest.lng < -180) {
var bearing = this.geodesic.inverse(start, dest).initialBearing;
var intersection = this.geodesic.intersection(start, bearing, antimeridianWest.point, antimeridianWest.bearing);
if (intersection) {
result = [[start, intersection], [new L.LatLng(intersection.lat, intersection.lng + 360), new L.LatLng(dest.lat, dest.lng + 360)]];
}
}
// crossing the "eastern" antimeridian
else if (dest.lng > 180) {
var bearing = this.geodesic.inverse(start, dest).initialBearing;
var intersection = this.geodesic.intersection(start, bearing, antimeridianEast.point, antimeridianEast.bearing);
if (intersection) {
result = [[start, intersection], [new L.LatLng(intersection.lat, intersection.lng - 360), new L.LatLng(dest.lat, dest.lng - 360)]];
}
}
}
// coming back over the antimeridian from the "other" side?
else if ((dest.lng >= -180) && (dest.lng <= 180)) {
// crossing the "western" antimeridian
if (start.lng < -180) {
var bearing = this.geodesic.inverse(start, dest).initialBearing;
var intersection = this.geodesic.intersection(start, bearing, antimeridianWest.point, antimeridianWest.bearing);
if (intersection) {
result = [[new L.LatLng(start.lat, start.lng + 360), new L.LatLng(intersection.lat, intersection.lng + 360)], [intersection, dest]];
}
}
// crossing the "eastern" antimeridian
else if (start.lng > 180) {
var bearing = this.geodesic.inverse(start, dest).initialBearing;
var intersection = this.geodesic.intersection(start, bearing, antimeridianWest.point, antimeridianWest.bearing);
if (intersection) {
result = [[new L.LatLng(start.lat, start.lng - 360), new L.LatLng(intersection.lat, intersection.lng - 360)], [intersection, dest]];
}
}
}
return result;
};
/**
* Linestrings of a given multilinestring that cross the antimeridian will be split in two separate linestrings.
* This function is used to wrap lines around when they cross the antimeridian
* It iterates over all linestrings and reconstructs the step-by-step if no split is needed.
* In case the line was split, the linestring ends at the antimeridian and a new linestring is created for the
* remaining points of the original linestring.
*
* @param multilinestring
* @return another multilinestring where segments crossing the antimeridian are split
*/
GeodesicGeometry.prototype.splitMultiLineString = function (multilinestring) {
var _this = this;
var result = [];
multilinestring.forEach(function (linestring) {
if (linestring.length === 1) {
result.push(linestring); // just a single point in linestring, no need to split
}
else {
var segment = [];
for (var j = 1; j < linestring.length; j++) {
var split = _this.splitLine(linestring[j - 1], linestring[j]);
segment.pop();
segment = segment.concat(split[0]);
if (split.length > 1) {
result.push(segment); // the line was split, so we end the linestring right here
segment = split[1]; // begin the new linestring with the second part of the split line
}
}
result.push(segment);
}
});
return result;
};
/**
* Creates a circular (constant radius), closed (1st pos == last pos) geodesic linestring.
* The number of vertices is calculated with: `vertices == steps + 1` (where 1st == last)
*
* @param center
* @param radius
* @return resulting linestring
*/
GeodesicGeometry.prototype.circle = function (center, radius) {
var vertices = [];
for (var i = 0; i < this.steps; i++) {
var point = this.geodesic.direct(center, 360 / this.steps * i, radius);
vertices.push(new L.LatLng(point.lat, point.lng));
}
// append first vertice to the end to close the linestring
vertices.push(new L.LatLng(vertices[0].lat, vertices[0].lng));
return vertices;
};
/**
* Handles splitting of circles at the antimeridian.
* @param linestring a linestring that resembles the geodesic circle
* @return a multilinestring that consist of one or two linestrings
*/
GeodesicGeometry.prototype.splitCircle = function (linestring) {
var result = [];
result = this.splitMultiLineString([linestring]);
// If the circle was split, it results in exactly three linestrings where first and last
// must be re-assembled because they belong to the same "side" of the split circle.
if (result.length === 3) {
result[2] = __spreadArrays(result[2], result[0]);
result.shift();
}
return result;
};
/**
* Calculates the distance between two positions on the earths surface
* @param start 1st position
* @param dest 2nd position
* @return the distance in **meters**
*/
GeodesicGeometry.prototype.distance = function (start, dest) {
return this.geodesic.inverse(new L.LatLng(start.lat, this.geodesic.wrap(start.lng, 180)), new L.LatLng(dest.lat, this.geodesic.wrap(dest.lng, 180))).distance;
};
GeodesicGeometry.prototype.multilineDistance = function (multilinestring) {
var _this = this;
var dist = [];
multilinestring.forEach(function (linestring) {
var segmentDistance = 0;
for (var j = 1; j < linestring.length; j++) {
segmentDistance += _this.distance(linestring[j - 1], linestring[j]);
}
dist.push(segmentDistance);
});
return dist;
};
GeodesicGeometry.prototype.updateStatistics = function (points, vertices) {
var stats = {};
stats.distanceArray = this.multilineDistance(points);
stats.totalDistance = stats.distanceArray.reduce(function (x, y) { return x + y; }, 0);
stats.points = 0;
points.forEach(function (item) {
stats.points += item.reduce(function (x) { return x + 1; }, 0);
});
stats.vertices = 0;
vertices.forEach(function (item) {
stats.vertices += item.reduce(function (x) { return x + 1; }, 0);
});
return stats;
};
return GeodesicGeometry;
}());
function instanceOfLatLngLiteral(object) {
return ((typeof object === "object")
&& (object !== null)
&& ('lat' in object)
&& ('lng' in object)
&& (typeof object.lat === "number")
&& (typeof object.lng === "number"));
}
function instanceOfLatLngTuple(object) {
return ((object instanceof Array)
&& (typeof object[0] === "number")
&& (typeof object[1] === "number"));
}
function instanceOfLatLngExpression(object) {
if (object instanceof L.LatLng) {
return true;
}
else if (instanceOfLatLngTuple(object)) {
return true;
}
else if (instanceOfLatLngLiteral(object)) {
return true;
}
else {
return false;
}
}
function latlngExpressiontoLatLng(input) {
if (input instanceof L.LatLng) {
return input;
}
else if (instanceOfLatLngTuple(input)) {
return new L.LatLng(input[0], input[1]);
}
else if (instanceOfLatLngLiteral(input)) {
return new L.LatLng(input.lat, input.lng);
}
else {
throw new Error("L.LatLngExpression expected. Unknown object found.");
}
}
function latlngExpressionArraytoLatLngArray(input) {
var latlng = [];
var _loop_1 = function (group) {
// it's a 1D-Array L.LatLngExpression[]
if (instanceOfLatLngExpression(group)) {
var sub_1 = [];
input.forEach(function (point) {
sub_1.push(latlngExpressiontoLatLng(point));
});
latlng.push(sub_1);
return "break";
}
// it's a 2D-Array L.LatLngExpression[][]
else if (group instanceof Array) {
if (instanceOfLatLngExpression(group[0])) {
var sub_2 = [];
group.forEach(function (point) {
sub_2.push(latlngExpressiontoLatLng(point));
});
latlng.push(sub_2);
}
else {
throw new Error("L.LatLngExpression[] | L.LatLngExpression[][] expected. Unknown object found.");
}
}
else {
throw new Error("L.LatLngExpression[] | L.LatLngExpression[][] expected. Unknown object found.");
}
};
for (var _i = 0, input_1 = input; _i < input_1.length; _i++) {
var group = input_1[_i];
var state_1 = _loop_1(group);
if (state_1 === "break")
break;
}
return latlng;
}
/**
* Draw geodesic lines based on L.Polyline
*/
var GeodesicLine = /** @class */ (function (_super) {
__extends(GeodesicLine, _super);
function GeodesicLine(latlngs, options) {
var _this = _super.call(this, [], options) || this;
/** these should be good for most use-cases */
_this.defaultOptions = { wrap: true, steps: 3 };
/** use this if you need some detailled info about the current geometry */
_this.statistics = {};
/** stores all positions that are used to create the geodesic line */
_this.points = [];
L.Util.setOptions(_this, __assign(__assign({}, _this.defaultOptions), options));
_this.geom = new GeodesicGeometry(_this.options);
if (latlngs !== undefined) {
_this.setLatLngs(latlngs);
}
return _this;
}
/** calculates the geodesics and update the polyline-object accordingly */
GeodesicLine.prototype.updateGeometry = function () {
var geodesic = [];
geodesic = this.geom.multiLineString(this.points);
this.statistics = this.geom.updateStatistics(this.points, geodesic);
if (this.options.wrap) {
var split = this.geom.splitMultiLineString(geodesic);
_super.prototype.setLatLngs.call(this, split);
}
else {
_super.prototype.setLatLngs.call(this, geodesic);
}
};
/**
* overwrites the original function with additional functionality to create a geodesic line
* @param latlngs an array (or 2d-array) of positions
*/
GeodesicLine.prototype.setLatLngs = function (latlngs) {
this.points = latlngExpressionArraytoLatLngArray(latlngs);
this.updateGeometry();
return this;
};
/**
* add a given point to the geodesic line object
* @param latlng point to add. The point will always be added to the last linestring of a multiline
* @param latlngs define a linestring to add the new point to. Read from points-property before (e.g. `line.addLatLng(Beijing, line.points[0]);`)
*/
GeodesicLine.prototype.addLatLng = function (latlng, latlngs) {
var point = latlngExpressiontoLatLng(latlng);
if (this.points.length === 0) {
this.points.push([point]);
}
else {
if (latlngs === undefined) {
this.points[this.points.length - 1].push(point);
}
else {
latlngs.push(point);
}
}
this.updateGeometry();
return this;
};
/**
* Creates geodesic lines from a given GeoJSON-Object.
* @param input GeoJSON-Object
*/
GeodesicLine.prototype.fromGeoJson = function (input) {
var latlngs = [];
var features = [];
if (input.type === "FeatureCollection") {
features = input.features;
}
else if (input.type === "Feature") {
features = [input];
}
else if (["MultiPoint", "LineString", "MultiLineString", "Polygon", "MultiPolygon"].includes(input.type)) {
features = [{
type: "Feature",
geometry: input,
properties: {}
}];
}
else {
console.log("[Leaflet.Geodesic] fromGeoJson() - Type \"" + input.type + "\" not supported.");
}
features.forEach(function (feature) {
switch (feature.geometry.type) {
case "MultiPoint":
case "LineString":
latlngs = __spreadArrays(latlngs, [L.GeoJSON.coordsToLatLngs(feature.geometry.coordinates, 0)]);
break;
case "MultiLineString":
case "Polygon":
latlngs = __spreadArrays(latlngs, L.GeoJSON.coordsToLatLngs(feature.geometry.coordinates, 1));
break;
case "MultiPolygon":
feature.geometry.coordinates.forEach(function (item) {
latlngs = __spreadArrays(latlngs, L.GeoJSON.coordsToLatLngs(item, 1));
});
break;
default:
console.log("[Leaflet.Geodesic] fromGeoJson() - Type \"" + feature.geometry.type + "\" not supported.");
}
});
if (latlngs.length) {
this.setLatLngs(latlngs);
}
return this;
};
/**
* Calculates the distance between two geo-positions
* @param start 1st position
* @param dest 2nd position
* @return the distance in meters
*/
GeodesicLine.prototype.distance = function (start, dest) {
return this.geom.distance(latlngExpressiontoLatLng(start), latlngExpressiontoLatLng(dest));
};
return GeodesicLine;
}(L.Polyline));
/**
* Can be used to create a geodesic circle based on L.Polyline
*/
var GeodesicCircleClass = /** @class */ (function (_super) {
__extends(GeodesicCircleClass, _super);
function GeodesicCircleClass(center, options) {
var _this = _super.call(this, [], options) || this;
_this.defaultOptions = { wrap: true, steps: 24, fill: true, noClip: true };
_this.statistics = {};
L.Util.setOptions(_this, __assign(__assign({}, _this.defaultOptions), options));
// merge/set options
var extendedOptions = _this.options;
_this.radius = (extendedOptions.radius === undefined) ? 1000 * 1000 : extendedOptions.radius;
_this.center = (center === undefined) ? new L.LatLng(0, 0) : latlngExpressiontoLatLng(center);
_this.geom = new GeodesicGeometry(_this.options);
// update the geometry
_this.update();
return _this;
}
/**
* Updates the geometry and re-calculates some statistics
*/
GeodesicCircleClass.prototype.update = function () {
var circle = this.geom.circle(this.center, this.radius);
this.statistics = this.geom.updateStatistics([[this.center]], [circle]);
// circumfence must be re-calculated from geodesic
this.statistics.totalDistance = this.geom.multilineDistance([circle]).reduce(function (x, y) { return x + y; }, 0);
if (this.options.wrap) {
var split = this.geom.splitCircle(circle);
_super.prototype.setLatLngs.call(this, split);
}
else {
_super.prototype.setLatLngs.call(this, circle);
}
};
/**
* Calculate the distance between the current center and an arbitrary position.
* @param latlng geo-position to calculate distance to
* @return distance in meters
*/
GeodesicCircleClass.prototype.distanceTo = function (latlng) {
var dest = latlngExpressiontoLatLng(latlng);
return this.geom.distance(this.center, dest);
};
/**
* Set a new center for the geodesic circle and update the geometry. Radius may also be set.
* @param center the new center
* @param radius the new radius
*/
GeodesicCircleClass.prototype.setLatLng = function (center, radius) {
this.center = latlngExpressiontoLatLng(center);
this.radius = radius ? radius : this.radius;
this.update();
};
/**
* Set a new radius for the geodesic circle and update the geometry. Center may also be set.
* @param radius the new radius
* @param center the new center
*/
GeodesicCircleClass.prototype.setRadius = function (radius, center) {
this.radius = radius;
this.center = center ? latlngExpressiontoLatLng(center) : this.center;
this.update();
};
return GeodesicCircleClass;
}(L.Polyline));
L.Geodesic = GeodesicLine;
L.geodesic = function () {
var args = [];
for (var _i = 0; _i < arguments.length; _i++) {
args[_i] = arguments[_i];
}
return new (GeodesicLine.bind.apply(GeodesicLine, __spreadArrays([void 0], args)))();
};
L.GeodesicCircle = GeodesicCircleClass;
L.geodesiccircle = function () {
var args = [];
for (var _i = 0; _i < arguments.length; _i++) {
args[_i] = arguments[_i];
}
return new (GeodesicCircleClass.bind.apply(GeodesicCircleClass, __spreadArrays([void 0], args)))();
};
exports.GeodesicCircleClass = GeodesicCircleClass;
exports.GeodesicLine = GeodesicLine;