/**
 * Copyright 2018 Bernie Jenny, Monash University, Melbourne, Australia.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Equal Earth is a projection inspired by the Robinson projection, but unlike
 * the Robinson projection retains the relative size of areas. The projection
 * was designed in 2018 by Bojan Savric, Tom Patterson and Bernhard Jenny.
 *
 * Publication:
 * Bojan Savric, Tom Patterson & Bernhard Jenny (2018). The Equal Earth map
 * projection, International Journal of Geographical Information Science,
 * DOI: 10.1080/13658816.2018.1504949
 *
 * Code released August 2018
 * Ported to JavaScript and adapted for mapshaper-proj by Matthew Bloch August 2018
 * Modified for proj4js by Andreas Hocevar by Andreas Hocevar March 2024
 */
import { ProjectionBase } from '.';
import type { VectorPoint } from '../../geometry';
import type { ProjectionParams, ProjectionTransform } from '.';
/**
 * # Equal Earth
 *
 * **Classification**: Pseudo cylindrical
 *
 * **Available forms**: Forward and inverse, spherical and ellipsoidal projection
 *
 * **Defined area**: Global
 *
 * **Alias**: eqearth
 *
 * **Domain**: 2D
 *
 * **Input type**: Geodetic coordinates
 *
 * **Output type**: Projected coordinates
 *
 * ## Projection String
 * ```
 * +proj=eqearth
 * ```
 *
 * ## Usage
 *
 * The Equal Earth projection is designed for world maps and retains the relative size of areas. It was inspired by the Robinson projection.
 *
 * Example:
 * ```
 * $ echo 122 47 | proj +proj=eqearth +R=1
 * 1.55    0.89
 * ```
 *
 * ## Parameters
 *
 * **Note**: All parameters for this projection are optional.
 *
 * ### Optional
 * - `+lon_0` (Central meridian)
 * - `+ellps` (Ellipsoid name)
 * - `+R` (Radius of the sphere)
 * - `+x_0` (False easting)
 * - `+y_0` (False northing)
 *
 * ## Further Reading
 * - [The Equal Earth map projection](https://www.researchgate.net/profile/Bojan_Savric2/publication/326879978_The_Equal_Earth_map_projection/links/5b69d0ae299bf14c6d951b77/The-Equal-Earth-map-projection.pdf) by Bojan Savric, Tom Patterson & Bernhard Jenny (2018)
 *
 * ![Equal Earth](https://github.com/Open-S2/s2-tools/blob/master/assets/proj4/projections/images/eqearth.png?raw=true)
 */
export declare class EqualEarth extends ProjectionBase implements ProjectionTransform {
    name: string;
    static names: string[];
    es: number;
    A1: number;
    A2: number;
    A3: number;
    A4: number;
    M: number;
    /**
     * Preps an EqualEarth projection
     * @param params - projection specific parameters
     */
    constructor(params?: ProjectionParams);
    /**
     * EqualEarth forward equations--mapping lon-lat to x-y
     * @param p - lon-lat WGS84 point
     */
    forward(p: VectorPoint): void;
    /**
     * EqualEarth inverse equations--mapping x-y to lon-lat
     * @param p - EqualEarth point
     */
    inverse(p: VectorPoint): void;
}
//# sourceMappingURL=eqearth.d.ts.map