"use strict";Object.defineProperty(exports, "__esModule", {value: true});// index.js
var _invariant = require('@turf/invariant');

// lib/arc.js
var D2R = Math.PI / 180;
var R2D = 180 / Math.PI;
var Coord = function(lon, lat) {
  this.lon = lon;
  this.lat = lat;
  this.x = D2R * lon;
  this.y = D2R * lat;
};
Coord.prototype.view = function() {
  return String(this.lon).slice(0, 4) + "," + String(this.lat).slice(0, 4);
};
Coord.prototype.antipode = function() {
  var anti_lat = -1 * this.lat;
  var anti_lon = this.lon < 0 ? 180 + this.lon : (180 - this.lon) * -1;
  return new Coord(anti_lon, anti_lat);
};
var LineString = function() {
  this.coords = [];
  this.length = 0;
};
LineString.prototype.move_to = function(coord) {
  this.length++;
  this.coords.push(coord);
};
var Arc = function(properties) {
  this.properties = properties || {};
  this.geometries = [];
};
Arc.prototype.json = function() {
  if (this.geometries.length <= 0) {
    return {
      geometry: { type: "LineString", coordinates: null },
      type: "Feature",
      properties: this.properties
    };
  } else if (this.geometries.length === 1) {
    return {
      geometry: { type: "LineString", coordinates: this.geometries[0].coords },
      type: "Feature",
      properties: this.properties
    };
  } else {
    var multiline = [];
    for (var i = 0; i < this.geometries.length; i++) {
      multiline.push(this.geometries[i].coords);
    }
    return {
      geometry: { type: "MultiLineString", coordinates: multiline },
      type: "Feature",
      properties: this.properties
    };
  }
};
Arc.prototype.wkt = function() {
  var wkt_string = "";
  var wkt = "LINESTRING(";
  var collect = function(c) {
    wkt += c[0] + " " + c[1] + ",";
  };
  for (var i = 0; i < this.geometries.length; i++) {
    if (this.geometries[i].coords.length === 0) {
      return "LINESTRING(empty)";
    } else {
      var coords = this.geometries[i].coords;
      coords.forEach(collect);
      wkt_string += wkt.substring(0, wkt.length - 1) + ")";
    }
  }
  return wkt_string;
};
var GreatCircle = function(start, end, properties) {
  if (!start || start.x === void 0 || start.y === void 0) {
    throw new Error(
      "GreatCircle constructor expects two args: start and end objects with x and y properties"
    );
  }
  if (!end || end.x === void 0 || end.y === void 0) {
    throw new Error(
      "GreatCircle constructor expects two args: start and end objects with x and y properties"
    );
  }
  this.start = new Coord(start.x, start.y);
  this.end = new Coord(end.x, end.y);
  this.properties = properties || {};
  var w = this.start.x - this.end.x;
  var h = this.start.y - this.end.y;
  var z = Math.pow(Math.sin(h / 2), 2) + Math.cos(this.start.y) * Math.cos(this.end.y) * Math.pow(Math.sin(w / 2), 2);
  this.g = 2 * Math.asin(Math.sqrt(z));
  if (this.g === Math.PI) {
    throw new Error(
      "it appears " + start.view() + " and " + end.view() + " are 'antipodal', e.g diametrically opposite, thus there is no single route but rather infinite"
    );
  } else if (isNaN(this.g)) {
    throw new Error(
      "could not calculate great circle between " + start + " and " + end
    );
  }
};
GreatCircle.prototype.interpolate = function(f) {
  var A = Math.sin((1 - f) * this.g) / Math.sin(this.g);
  var B = Math.sin(f * this.g) / Math.sin(this.g);
  var x = A * Math.cos(this.start.y) * Math.cos(this.start.x) + B * Math.cos(this.end.y) * Math.cos(this.end.x);
  var y = A * Math.cos(this.start.y) * Math.sin(this.start.x) + B * Math.cos(this.end.y) * Math.sin(this.end.x);
  var z = A * Math.sin(this.start.y) + B * Math.sin(this.end.y);
  var lat = R2D * Math.atan2(z, Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2)));
  var lon = R2D * Math.atan2(y, x);
  return [lon, lat];
};
GreatCircle.prototype.Arc = function(npoints, options) {
  var first_pass = [];
  if (!npoints || npoints <= 2) {
    first_pass.push([this.start.lon, this.start.lat]);
    first_pass.push([this.end.lon, this.end.lat]);
  } else {
    var delta = 1 / (npoints - 1);
    for (var i = 0; i < npoints; ++i) {
      var step = delta * i;
      var pair = this.interpolate(step);
      first_pass.push(pair);
    }
  }
  var bHasBigDiff = false;
  var dfMaxSmallDiffLong = 0;
  var dfDateLineOffset = options && options.offset ? options.offset : 10;
  var dfLeftBorderX = 180 - dfDateLineOffset;
  var dfRightBorderX = -180 + dfDateLineOffset;
  var dfDiffSpace = 360 - dfDateLineOffset;
  for (var j = 1; j < first_pass.length; ++j) {
    var dfPrevX = first_pass[j - 1][0];
    var dfX = first_pass[j][0];
    var dfDiffLong = Math.abs(dfX - dfPrevX);
    if (dfDiffLong > dfDiffSpace && (dfX > dfLeftBorderX && dfPrevX < dfRightBorderX || dfPrevX > dfLeftBorderX && dfX < dfRightBorderX)) {
      bHasBigDiff = true;
    } else if (dfDiffLong > dfMaxSmallDiffLong) {
      dfMaxSmallDiffLong = dfDiffLong;
    }
  }
  var poMulti = [];
  if (bHasBigDiff && dfMaxSmallDiffLong < dfDateLineOffset) {
    var poNewLS = [];
    poMulti.push(poNewLS);
    for (var k = 0; k < first_pass.length; ++k) {
      var dfX0 = parseFloat(first_pass[k][0]);
      if (k > 0 && Math.abs(dfX0 - first_pass[k - 1][0]) > dfDiffSpace) {
        var dfX1 = parseFloat(first_pass[k - 1][0]);
        var dfY1 = parseFloat(first_pass[k - 1][1]);
        var dfX2 = parseFloat(first_pass[k][0]);
        var dfY2 = parseFloat(first_pass[k][1]);
        if (dfX1 > -180 && dfX1 < dfRightBorderX && dfX2 === 180 && k + 1 < first_pass.length && first_pass[k - 1][0] > -180 && first_pass[k - 1][0] < dfRightBorderX) {
          poNewLS.push([-180, first_pass[k][1]]);
          k++;
          poNewLS.push([first_pass[k][0], first_pass[k][1]]);
          continue;
        } else if (dfX1 > dfLeftBorderX && dfX1 < 180 && dfX2 === -180 && k + 1 < first_pass.length && first_pass[k - 1][0] > dfLeftBorderX && first_pass[k - 1][0] < 180) {
          poNewLS.push([180, first_pass[k][1]]);
          k++;
          poNewLS.push([first_pass[k][0], first_pass[k][1]]);
          continue;
        }
        if (dfX1 < dfRightBorderX && dfX2 > dfLeftBorderX) {
          var tmpX = dfX1;
          dfX1 = dfX2;
          dfX2 = tmpX;
          var tmpY = dfY1;
          dfY1 = dfY2;
          dfY2 = tmpY;
        }
        if (dfX1 > dfLeftBorderX && dfX2 < dfRightBorderX) {
          dfX2 += 360;
        }
        if (dfX1 <= 180 && dfX2 >= 180 && dfX1 < dfX2) {
          var dfRatio = (180 - dfX1) / (dfX2 - dfX1);
          var dfY = dfRatio * dfY2 + (1 - dfRatio) * dfY1;
          poNewLS.push([
            first_pass[k - 1][0] > dfLeftBorderX ? 180 : -180,
            dfY
          ]);
          poNewLS = [];
          poNewLS.push([
            first_pass[k - 1][0] > dfLeftBorderX ? -180 : 180,
            dfY
          ]);
          poMulti.push(poNewLS);
        } else {
          poNewLS = [];
          poMulti.push(poNewLS);
        }
        poNewLS.push([dfX0, first_pass[k][1]]);
      } else {
        poNewLS.push([first_pass[k][0], first_pass[k][1]]);
      }
    }
  } else {
    var poNewLS0 = [];
    poMulti.push(poNewLS0);
    for (var l = 0; l < first_pass.length; ++l) {
      poNewLS0.push([first_pass[l][0], first_pass[l][1]]);
    }
  }
  var arc = new Arc(this.properties);
  for (var m = 0; m < poMulti.length; ++m) {
    var line = new LineString();
    arc.geometries.push(line);
    var points = poMulti[m];
    for (var j0 = 0; j0 < points.length; ++j0) {
      line.move_to(points[j0]);
    }
  }
  return arc;
};

// index.js
function greatCircle(start, end, options) {
  options = options || {};
  if (typeof options !== "object")
    throw new Error("options is invalid");
  var properties = options.properties;
  var npoints = options.npoints;
  var offset = options.offset;
  start = _invariant.getCoord.call(void 0, start);
  end = _invariant.getCoord.call(void 0, end);
  properties = properties || {};
  npoints = npoints || 100;
  offset = offset || 10;
  var generator = new GreatCircle(
    { x: start[0], y: start[1] },
    { x: end[0], y: end[1] },
    properties
  );
  var line = generator.Arc(npoints, { offset });
  return line.json();
}
var turf_great_circle_default = greatCircle;



exports.default = turf_great_circle_default; exports.greatCircle = greatCircle;
/*!
 * Copyright (c) 2019, Dane Springmeyer
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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 */
//# sourceMappingURL=index.cjs.map