import { ProjectionBase } from '.';
import type { VectorPoint } from '../../geometry';
import type { ProjectionParams, ProjectionTransform } from '.';
/**
 * # Orthographic
 *
 * The orthographic projection is a perspective azimuthal projection centered
 * around a given latitude and longitude.
 *
 * **Classification**: Azimuthal
 *
 * **Available forms**: Forward and inverse, spherical and ellipsoidal
 *
 * **Defined area**: Global, although only one hemisphere can be seen at a time
 *
 * **Alias**: ortho
 *
 * **Domain**: 2D
 *
 * **Input type**: Geodetic coordinates
 *
 * **Output type**: Projected coordinates
 *
 * ## Projection String
 * ```
 * +proj=ortho
 * ```
 *
 * ## Required Parameters
 * - None
 *
 * ## Optional Parameters
 * - `+alpha=<value>`: Azimuth clockwise from north at the center of projection. *Defaults to 0.0.* (added in PROJ 9.5.0)
 * - `+k_0=<value>`: Scale factor. Determines scale factor used in the projection. *Defaults to 1.0.* (added in PROJ 9.5.0)
 * - `+lon_0=<value>`
 * - `+lat_0=<value>`
 * - `+ellps=<value>`
 * - `+R=<value>`
 * - `+x_0=<value>`
 * - `+y_0=<value>`
 *
 * ## Notes
 * - Before PROJ 7.2, only the spherical formulation was implemented. To replicate PROJ < 7.2 results with newer versions, force the ellipsoid to a sphere using `+f=0`.
 * - This projection method corresponds to `EPSG:9840` (or `EPSG:1130` with `k_0` or `alpha`).
 *
 * ![Orthographic](https://github.com/Open-S2/s2-tools/blob/master/assets/proj4/projections/images/ortho.png?raw=true)
 */
export declare class Orthographic extends ProjectionBase implements ProjectionTransform {
    name: string;
    static names: string[];
    sinP14: number;
    cosP14: number;
    /**
     * Preps an Orthographic projection
     * @param params - projection specific parameters
     */
    constructor(params?: ProjectionParams);
    /**
     * Orthographic forward equations--mapping lon-lat to x-y
     * @param p - lon-lat WGS84 point
     */
    forward(p: VectorPoint): void;
    /**
     * Orthographic inverse equations--mapping x-y to lon-lat
     * @param p - Orthographic point
     */
    inverse(p: VectorPoint): void;
}
//# sourceMappingURL=ortho.d.ts.map