import type { Node } from '../Node';
import type { Group } from '../shapes/Group';
export declare class SpatialIndex {
    private cellSize;
    private grid;
    private entries;
    private stale;
    constructor(cellSize?: number);
    markStale(): void;
    rebuild(root: Group): void;
    ensureFresh(root: Group): void;
    private insert;
    private cellsForBounds;
    /** Candidates at a world point (deduped, high z-index first). */
    queryPoint(x: number, y: number): Node[];
    get size(): number;
    clear(): void;
}