import type { ElementSet } from "../satellites/types.ts";
import type { SatelliteState } from "./satellite-layer.ts";
/** What happens to the groups that are not the one in focus. `dim` draws them dimmer. `hide` does not draw them. */
export type SatelliteOthers = "dim" | "hide";
/** The group a view is showing on its own, and what it does with the others. `null` when every group is as the page set it. */
export interface SatelliteFocus {
    name: string;
    others: SatelliteOthers;
}
/** How one group is drawn while a focus is set. `focus` is the chosen group, `dim` a group drawn dimmer, `hidden` a group not drawn, `plain` a group with no focus in force. */
export type SatelliteEmphasis = "focus" | "dim" | "hidden" | "plain";
/** What `focusSatelliteGroup` returns. `reason: "not-set"` is a group `setSatellites` has not set; the call changes nothing and does not throw. */
export interface SatelliteFocusAnswer {
    ok: boolean;
    group?: string | null;
    count?: number;
    changed?: boolean;
    reason?: "not-set";
}
/**
 * Whether a group is drawn, and whether its dots take the dim value, for a focus. A group the page hid stays hidden unless it is the one in focus. The page's own shown state is not an input that this changes.
 *
 * @param name - The group's name.
 * @param ownVisible - Whether the page is showing the group (`showSatellites`).
 * @param focus - The focus in force, or `null`.
 * @returns `drawn` (the group is placed), `dim` (1 to draw it dimmer, 0 to leave it) and `emphasis`.
 */
export declare function satelliteEmphasis(name: string, ownVisible: boolean, focus: SatelliteFocus | null): {
    drawn: boolean;
    dim: number;
    emphasis: SatelliteEmphasis;
};
/**
 * Put the focus on one group, or clear it with `null`. A name that is not a group already set is refused.
 *
 * @param state - The view's satellite state.
 * @param name - The group's name, or `null` to clear.
 * @param options - `others` is `dim` when left out. `frame` is read by the element, not here.
 * @returns The answer. `changed` is false when the focus was already that.
 */
export declare function applySatelliteFocus(state: SatelliteState, name: string | null, options?: {
    others?: SatelliteOthers;
}): SatelliteFocusAnswer;
/** One group as `satelliteGroups` reports it: the page's own shown state, how the focus treats it, and how many the last draw placed. */
export interface SatelliteGroupRow {
    name: string;
    count: number;
    visible: boolean;
    placed: number;
    emphasis: SatelliteEmphasis;
}
/**
 * The groups now set, in the order they were set, with the focus applied for reading. `placed` is 0 when the group is not drawn.
 *
 * @param state - The view's satellite state.
 * @returns One row a group.
 */
export declare function satelliteGroupRows(state: SatelliteState): SatelliteGroupRow[];
/** The greatest apogee a shell is pulled out to, in Earth radii. Past this, one far satellite would shrink the Earth instead of showing the group. */
export declare const SHELL_CAP = 8;
/**
 * The shell of a group, in Earth radii from the Earth's centre: the greatest apogee of its element sets, from the mean motion (revolutions a day) and the eccentricity.
 * One revolution a day is 6.62 Earth radii (Kepler's third law, an Earth of 6371 km). A group with no usable set is the Earth's own radius. The result is never above {@link SHELL_CAP}.
 *
 * @param sets - The group's element sets.
 * @returns The shell, from 1 to 8.
 */
export declare function shellRadiusOf(sets: readonly Pick<ElementSet, "MEAN_MOTION" | "ECCENTRICITY">[]): number;
/**
 * The zoom that puts a shell of `shell` Earth radii inside the space view. At zoom 1 the Earth fills `earthSize` of the shorter side. The shell fills about 0.92 of that side.
 *
 * @param shell - The shell, in Earth radii.
 * @param earthSize - The share of the shorter side the Earth fills at zoom 1.
 * @param aspect - The view's width over its height.
 * @param min - The least zoom the view allows.
 * @param max - The greatest zoom the view allows.
 * @returns The zoom.
 */
export declare function zoomForPerspectiveShell(shell: number, earthSize: number, aspect: number, min: number, max: number): number;
/**
 * The zoom that puts a shell of `shell` Earth radii inside the realistic Earth's picture. At zoom 1 the Earth and its glow fill the shorter side (the glow is 1.08 radii). The shell fills about 0.92 of that side.
 *
 * @param shell - The shell, in Earth radii.
 * @param width - The view's width in CSS pixels.
 * @param height - The view's height in CSS pixels.
 * @param min - The least zoom the view allows.
 * @param max - The greatest zoom the view allows.
 * @returns The zoom.
 */
export declare function zoomForOrthographicShell(shell: number, width: number, height: number, min: number, max: number): number;