/**
 * Several points gathered into one on the screen: where it is drawn and which points are in it.
 *
 * @example
 * ```ts
 * import { clusterPoints, type Cluster } from "@johnmorrisdotca/chikyu-earth/markers";
 *
 * const clusters: Cluster[] = clusterPoints([0, 1], 2, [10, 12], [10, 11], 28);
 * console.log(clusters[0]?.members);
 * ```
 */
export interface Cluster {
    x: number;
    y: number;
    /** Indices of the points in it. */
    members: number[];
}
/**
 * Group the points `indices` (into `xs` and `ys`) by the grid cell they fall in. A cell with one point is that point alone; with more it is one cluster at their
 * average. Order is stable: clusters come in the order their first member was seen.
 *
 * @param indices - Which points to group: indices into `xs` and `ys`.
 * @param count - How many of `indices` to read.
 * @param xs - Every point's x on the screen, in pixels.
 * @param ys - Every point's y on the screen, in pixels.
 * @param cell - The side of a grid cell in pixels; points in one cell join.
 * @returns The clusters, each with the indices of its members; a lone point is a cluster of one.
 *
 * @example
 * ```ts
 * import { clusterPoints } from "@johnmorrisdotca/chikyu-earth/markers";
 *
 * const xs = [10, 14, 200];
 * const ys = [10, 12, 200];
 * console.log(clusterPoints([0, 1, 2], 3, xs, ys, 28).map((cluster) => cluster.members));
 * ```
 */
export declare function clusterPoints(indices: ArrayLike<number>, count: number, xs: ArrayLike<number>, ys: ArrayLike<number>, cell: number): Cluster[];