/**
 * Returns elements that have at least one corner visible in the viewport
 * and not occluded by other elements.
 */
export declare function probeViewport(): Element[];
export declare class PointSet {
    maxX: number;
    maxY: number;
    private map;
    constructor(maxX: number, maxY: number);
    getAll(): Generator<{
        x: number;
        y: number;
    }, void, unknown>;
    has(x: number, y: number): boolean;
    add(x: number, y: number): void;
}