export interface HitBounds {
    xMin: number;
    xMax: number;
    yMin: number;
    yMax: number;
}
/**
 * Wraps SpatialGrid with dirty-flag bookkeeping + the cell-size heuristic
 * (~√n cells), so chart code no longer repeats the insertion loop scaffold.
 * Callers drive the iteration through `rebuild` and the `visit` callback,
 * which lets scatter (flat array) and line (series-indexed array) share
 * the same code path.
 */
export declare class SpatialHitTester {
    private _grid;
    private _dirty;
    markDirty(): void;
    get isDirty(): boolean;
    /**
     * Rebuild the grid. `forEachPoint` is called once with an insert
     * function; the caller drives iteration. Cleared when `pointCount`
     * is zero.
     */
    rebuild(bounds: HitBounds, pointCount: number, forEachPoint: (insert: (idx: number, x: number, y: number) => void) => void): void;
    /**
     * Query the nearest point within `radiusPx` of (dataX, dataY).
     */
    query(dataX: number, dataY: number, radiusPx: number, pxPerDataX: number, pxPerDataY: number, xData: Float32Array | null, yData: Float32Array | null): number;
    clear(): void;
}