import type { SheetOptions } from "./earth.ts";
/** How far the view of the day and night globe is tipped to show the north (degrees): the line between day and night is then a curve. */
export declare const DAY_NIGHT_TIP = 20;
/**
 * The turn of the globe on the day and night sheet for a moment: the Sun's longitude less 90 degrees at the middle, so the lit half is on the right, tipped to show the north.
 * @param ms - The moment, in milliseconds since the Unix epoch.
 * @returns The place at the middle of the globe, the place where the Sun is straight overhead and the roll of the globe about the line of sight, in degrees.
 *
 * @example
 * ```ts
 * import { dayNightView } from "@johnmorrisdotca/chikyu-earth/sheets";
 *
 * const view = dayNightView(Date.UTC(2026, 5, 21, 12));
 * console.log(view.sun.lat.toFixed(1));
 * ```
 */
export declare function dayNightView(ms: number): {
    centre: [number, number];
    sun: {
        lon: number;
        lat: number;
    };
    roll: number;
};
/**
 * The line between day and night at a moment: the points 90 degrees from where the Sun is straight overhead, as longitude and latitude.
 * @param ms - The moment, in milliseconds since the Unix epoch.
 * @param points - How many points (at least 3, default 72).
 * @returns The points in order round the Earth.
 *
 * @example
 * ```ts
 * import { terminator } from "@johnmorrisdotca/chikyu-earth/sheets";
 *
 * console.log(terminator(Date.UTC(2026, 2, 20, 12), 8).length);
 * ```
 */
export declare function terminator(ms: number, points?: number): [number, number][];
/**
 * The day and night sheet: the Earth with the Sun's light coming from the right, the lit half left white (day) and the dark half hatched (night), the line between them thick, and three facts, for the date and time you give. The line is worked out from the package's own sun position.
 * @param ms - The moment, in milliseconds since the Unix epoch.
 * @param options - The room, the language and the type.
 * @returns The `<svg>` markup, carrying the place of the Sun as `data-sun`.
 *
 * @example
 * ```ts
 * import { dayNightSvg } from "@johnmorrisdotca/chikyu-earth/sheets";
 *
 * const svg = dayNightSvg(Date.UTC(2026, 5, 21, 12), { widthMm: 184.6, heightMm: 180 });
 * console.log(svg.includes("data-sun="), svg.includes("Night"));
 * ```
 */
export declare function dayNightSvg(ms: number, options: SheetOptions): string;
/**
 * The seasons sheet: the Sun in the middle, the Earth's orbit as a ring, and the Earth at four points of it (March, June, September and December), each with its tilt, the dark half hatched, the season of the northern half named, and three facts.
 * The axis leans the same way at all four, so in June the north leans toward the Sun and in December away from it.
 * @param options - The room, the language and the type.
 * @returns The `<svg>` markup.
 *
 * @example
 * ```ts
 * import { seasonsSvg } from "@johnmorrisdotca/chikyu-earth/sheets";
 *
 * const svg = seasonsSvg({ widthMm: 184.6, heightMm: 180, lang: "en" });
 * console.log(svg.includes("Summer"), svg.includes("Winter"));
 * ```
 */
export declare function seasonsSvg(options: SheetOptions): string;