@visx/vendor/vendor-cjs/d3-geo/src/projection/albersUsa.js

vendored packages for visx

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = _default;
var _math = require("../math.js");
var _albers = _interopRequireDefault(require("./albers.js"));
var _conicEqualArea = _interopRequireDefault(require("./conicEqualArea.js"));
var _fit = require("./fit.js");
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
// The projections must have mutually exclusive clip regions on the sphere,
// as this will avoid emitting interleaving lines and polygons.
function multiplex(streams) {
  var n = streams.length;
  return {
    point: function (x, y) {
      var i = -1;
      while (++i < n) streams[i].point(x, y);
    },
    sphere: function () {
      var i = -1;
      while (++i < n) streams[i].sphere();
    },
    lineStart: function () {
      var i = -1;
      while (++i < n) streams[i].lineStart();
    },
    lineEnd: function () {
      var i = -1;
      while (++i < n) streams[i].lineEnd();
    },
    polygonStart: function () {
      var i = -1;
      while (++i < n) streams[i].polygonStart();
    },
    polygonEnd: function () {
      var i = -1;
      while (++i < n) streams[i].polygonEnd();
    }
  };
}

// A composite projection for the United States, configured by default for
// 960×500. The projection also works quite well at 960×600 if you change the
// scale to 1285 and adjust the translate accordingly. The set of standard
// parallels for each region comes from USGS, which is published here:
// http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html#albers
function _default() {
  var cache,
    cacheStream,
    lower48 = (0, _albers.default)(),
    lower48Point,
    alaska = (0, _conicEqualArea.default)().rotate([154, 0]).center([-2, 58.5]).parallels([55, 65]),
    alaskaPoint,
    // EPSG:3338
    hawaii = (0, _conicEqualArea.default)().rotate([157, 0]).center([-3, 19.9]).parallels([8, 18]),
    hawaiiPoint,
    // ESRI:102007
    point,
    pointStream = {
      point: function (x, y) {
        point = [x, y];
      }
    };
  function albersUsa(coordinates) {
    var x = coordinates[0],
      y = coordinates[1];
    return point = null, (lower48Point.point(x, y), point) || (alaskaPoint.point(x, y), point) || (hawaiiPoint.point(x, y), point);
  }
  albersUsa.invert = function (coordinates) {
    var k = lower48.scale(),
      t = lower48.translate(),
      x = (coordinates[0] - t[0]) / k,
      y = (coordinates[1] - t[1]) / k;
    return (y >= 0.120 && y < 0.234 && x >= -0.425 && x < -0.214 ? alaska : y >= 0.166 && y < 0.234 && x >= -0.214 && x < -0.115 ? hawaii : lower48).invert(coordinates);
  };
  albersUsa.stream = function (stream) {
    return cache && cacheStream === stream ? cache : cache = multiplex([lower48.stream(cacheStream = stream), alaska.stream(stream), hawaii.stream(stream)]);
  };
  albersUsa.precision = function (_) {
    if (!arguments.length) return lower48.precision();
    lower48.precision(_), alaska.precision(_), hawaii.precision(_);
    return reset();
  };
  albersUsa.scale = function (_) {
    if (!arguments.length) return lower48.scale();
    lower48.scale(_), alaska.scale(_ * 0.35), hawaii.scale(_);
    return albersUsa.translate(lower48.translate());
  };
  albersUsa.translate = function (_) {
    if (!arguments.length) return lower48.translate();
    var k = lower48.scale(),
      x = +_[0],
      y = +_[1];
    lower48Point = lower48.translate(_).clipExtent([[x - 0.455 * k, y - 0.238 * k], [x + 0.455 * k, y + 0.238 * k]]).stream(pointStream);
    alaskaPoint = alaska.translate([x - 0.307 * k, y + 0.201 * k]).clipExtent([[x - 0.425 * k + _math.epsilon, y + 0.120 * k + _math.epsilon], [x - 0.214 * k - _math.epsilon, y + 0.234 * k - _math.epsilon]]).stream(pointStream);
    hawaiiPoint = hawaii.translate([x - 0.205 * k, y + 0.212 * k]).clipExtent([[x - 0.214 * k + _math.epsilon, y + 0.166 * k + _math.epsilon], [x - 0.115 * k - _math.epsilon, y + 0.234 * k - _math.epsilon]]).stream(pointStream);
    return reset();
  };
  albersUsa.fitExtent = function (extent, object) {
    return (0, _fit.fitExtent)(albersUsa, extent, object);
  };
  albersUsa.fitSize = function (size, object) {
    return (0, _fit.fitSize)(albersUsa, size, object);
  };
  albersUsa.fitWidth = function (width, object) {
    return (0, _fit.fitWidth)(albersUsa, width, object);
  };
  albersUsa.fitHeight = function (height, object) {
    return (0, _fit.fitHeight)(albersUsa, height, object);
  };
  function reset() {
    cache = cacheStream = null;
    return albersUsa;
  }
  return albersUsa.scale(1070);
}