/** The view: the point of the Earth at the middle of the disc, the disc's radius and its centre, in CSS pixels. */
/**
 * The view: the point of the Earth at the middle of the disc, the disc's radius and its centre, in CSS pixels.
 *
 * @example
 * ```ts
 * import { project, type Pose } from "@johnmorrisdotca/chikyu-earth/markers";
 *
 * const pose: Pose = { lon: 10, lat: 20, radius: 100, cx: 150, cy: 150 };
 * console.log(project(10, 20, pose));
 * ```
 */
export interface Pose {
    lon: number;
    lat: number;
    radius: number;
    cx: number;
    cy: number;
}
/**
 * Project a longitude and latitude (degrees) to the screen. `z` is the cosine of the angle from the middle of the disc: above 0 the point faces
 * the viewer, below it is on the far side. North is up.
 *
 * @param lon - Longitude in degrees east.
 * @param lat - Latitude in degrees north.
 * @param pose - The view.
 * @returns The point's x and y in pixels and `z`, the cosine of its angle from the middle of the disc.
 *
 * @example
 * ```ts
 * import { project } from "@johnmorrisdotca/chikyu-earth/markers";
 *
 * const where = project(139.69, 35.69, { lon: 139.69, lat: 35.69, radius: 200, cx: 210, cy: 210 });
 * console.log(where.x, where.y, where.z);
 * ```
 */
export declare function project(lon: number, lat: number, pose: Pose): {
    x: number;
    y: number;
    z: number;
};
/**
 * Project many points into flat arrays (reused between calls); `z` is the cosine used for a point's facing test.
 *
 * @param lons - Longitudes in degrees.
 * @param lats - Latitudes in degrees.
 * @param count - How many points to project.
 * @param pose - The view.
 * @param xs - Filled with each point's x in pixels.
 * @param ys - Filled with each point's y in pixels.
 * @param zs - Filled with each point's `z`: above 0 it faces the viewer.
 *
 * @example
 * ```ts
 * import { projectAll } from "@johnmorrisdotca/chikyu-earth/markers";
 *
 * const xs = new Float32Array(2);
 * const ys = new Float32Array(2);
 * const zs = new Float32Array(2);
 * projectAll([0, 180], [0, 0], 2, { lon: 0, lat: 0, radius: 100, cx: 100, cy: 100 }, xs, ys, zs);
 * console.log(zs[0], zs[1]);
 * ```
 */
export declare function projectAll(lons: ArrayLike<number>, lats: ArrayLike<number>, count: number, pose: Pose, xs: Float32Array, ys: Float32Array, zs: Float32Array): void;
/**
 * The pixel ratio for an overlay canvas: the device's, to 2, held to 4096 a side and 6 million pixels (the same budget as the 3D canvas).
 *
 * @param width - The canvas's width in CSS pixels.
 * @param height - The canvas's height in CSS pixels.
 * @param deviceRatio - The device's pixel ratio.
 * @param maxSide - The most pixels on a side.
 * @param maxPixels - The most pixels in all.
 * @returns The ratio to draw at, between 0.1 and 2.
 *
 * @example
 * ```ts
 * import { canvasRatio } from "@johnmorrisdotca/chikyu-earth/markers";
 *
 * console.log(canvasRatio(420, 420, 3), canvasRatio(5000, 3000, 2));
 * ```
 */
export declare function canvasRatio(width: number, height: number, deviceRatio: number, maxSide?: number, maxPixels?: number): number;