import { ProjectionBase } from '.';
import type { VectorPoint } from '../../geometry';
import type { ProjectionParams, ProjectionTransform } from '.';
/**
 * # Gnomonic (gnom)
 *
 * For a sphere, the gnomonic projection is a projection from the center of
 * the sphere onto a plane tangent to the center point of the projection.
 * This projects great circles to straight lines.  For an ellipsoid, it is
 * the limit of a doubly azimuthal projection, a projection where the
 * azimuths from 2 points are preserved, as the two points merge into the
 * center point.  In this case, geodesics project to approximately straight
 * lines (these are exactly straight if the geodesic includes the center
 * point).  For details, see Section 8 of :cite:`Karney2013`.
 *
 * **Classification**: Azimuthal
 *
 * **Available forms**: Forward and inverse, spherical and ellipsoidal
 *
 * **Defined area**: Within a quarter circumference of the center point
 *
 * **Alias**: gnom
 *
 * **Domain**: 2D
 *
 * **Input type**: Geodetic coordinates
 *
 * **Output type**: Projected coordinates
 *
 * ## Projection String
 * ```
 * +proj=gnom +lat_0=90 +lon_0=-50 +R=6.4e6
 * ```
 *
 * ## Required Parameters
 * - None, all parameters are optional for this projection.
 *
 * ## Optional Parameters
 * - `+lon_0`: Longitude of origin (central meridian).
 * - `+lat_0`: Latitude of origin.
 * - `+x_0`: False easting.
 * - `+y_0`: False northing.
 * - `+ellps`: Ellipsoid.
 * - `+R`: Earth radius.
 *
 * Reference:
 * Wolfram Mathworld "Gnomonic Projection"
 * http://mathworld.wolfram.com/GnomonicProjection.html
 * Accessed: 12th November 2009
 *
 * ![Gnomonic](https://github.com/Open-S2/s2-tools/blob/master/assets/proj4/projections/images/gnom.png?raw=true)
 */
export declare class Gnomonic extends ProjectionBase implements ProjectionTransform {
    name: string;
    static names: string[];
    rc: number;
    phic0: number;
    sinP14: number;
    cosP14: number;
    infinityDist: number;
    /**
     * Preps an Gnomonic projection
     * @param params - projection specific parameters
     */
    constructor(params?: ProjectionParams);
    /**
     * Gnomonic forward equations--mapping lon-lat to x-y
     * @param p - lon-lat WGS84 point
     */
    forward(p: VectorPoint): void;
    /**
     * Gnomonic inverse equations--mapping x-y to lon-lat
     * @param p - Gnomonic point
     */
    inverse(p: VectorPoint): void;
}
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