text: // Copyright (c) 2019 Uber Technologies, Inc.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE.
  
  import {WebMercatorViewport} from 'deck.gl';
  
  export function hexagonToPolygonGeo({object}, properties, radius, mapState) {
    const viewport = new WebMercatorViewport(mapState);
  
    const screenCenter = viewport.projectFlat(object.position);
    const {pixelsPerMeter} = viewport.getDistanceScales();
    const pixRadius = radius * pixelsPerMeter[0];
  
    const coordinates = [];
  
    for (let i = 0; i < 6; i++) {
      const vertex = hex_corner(screenCenter, pixRadius, i);
      coordinates.push(viewport.unprojectFlat(vertex));
    }
  
    coordinates.push(coordinates[0]);
  
    return {
      geometry: {
        coordinates,
        type: 'LineString'
      },
      properties
    };
  }
  
  function hex_corner(center, radius, i) {
    const angle_deg = 60 * i + 30;
    const angle_rad = Math.PI / 180 * angle_deg;
  
    return [
      center[0] + radius * Math.cos(angle_rad),
      center[1] + radius * Math.sin(angle_rad)
    ];
  }
  