import type { HeightTile } from "./height-tile";
/**
 * Generates contour lines from a HeightTile
 *
 * @param interval Vertical distance between contours
 * @param tile The input height tile, where values represent the height at the top-left of each pixel
 * @param extent Vector tile extent (default 4096)
 * @param buffer How many pixels into each neighboring tile to include in a tile
 * @returns an object where keys are the elevation, and values are a list of `[x1, y1, x2, y2, ...]`
 * contour lines in tile coordinates
 */
export default function generateIsolines(interval: number, tile: HeightTile, extent?: number, buffer?: number): {
    [ele: number]: number[][];
};