import type { TileInView } from './index.js';
/**
 * Given a camera position, get the tiles in current view
 * @param zoom - the zoom level
 * @param lon - the longitude
 * @param lat - the latitude
 * @param matrix - the projection matrix
 * @param radius - the radius of the sphere
 * @returns list of Tile IDs
 */
export declare function getTilesInViewS2(zoom: number, lon: number, lat: number, matrix: Float32Array, radius?: number): TileInView[];
/**
 * check if any 4 points in a rectangle is less than zero
 * @param zero - the zero reference point to compare against
 * @param bl - bottom left point
 * @param br - bottom right point
 * @param tl - top left point
 * @param tr - top right point
 * @returns true if any point is less than zero
 */
export declare function lessThanZero(zero: number, bl: number, br: number, tl: number, tr: number): boolean;