/**
 * Open-addressing hash map for voxel block masks backed by typed arrays.
 * Replaces Map<number, [number, number]> to eliminate V8 Map overhead and
 * per-entry tuple allocations that cause GC pressure.
 *
 * Keys are non-negative block indices. Values are lo/hi uint32 mask pairs.
 * Uses Fibonacci hashing with linear probing and backward-shift deletion.
 */
declare class BlockMaskMap {
    keys: Int32Array;
    lo: Uint32Array;
    hi: Uint32Array;
    private _size;
    private _capacity;
    private _mask;
    constructor(initialCapacity?: number);
    get size(): number;
    /**
     * Find the slot for a key. If the key exists, keys[slot] === key.
     * If the key doesn't exist, keys[slot] === -1 (empty slot for insertion).
     *
     * @param key - Block index to look up.
     * @returns Slot index into keys/lo/hi arrays.
     */
    slot(key: number): number;
    has(key: number): boolean;
    /**
     * Insert at a slot known to be empty (keys[slot] === -1).
     * Caller must have obtained slot via slot() and verified it is empty.
     *
     * @param slot - Empty slot index.
     * @param key - Block index to insert.
     * @param loVal - Lower 32 bits of voxel mask.
     * @param hiVal - Upper 32 bits of voxel mask.
     */
    insertAt(slot: number, key: number, loVal: number, hiVal: number): void;
    /**
     * Set key to lo/hi values. Inserts if key doesn't exist, updates if it does.
     *
     * @param key - Block index.
     * @param loVal - Lower 32 bits of voxel mask.
     * @param hiVal - Upper 32 bits of voxel mask.
     */
    set(key: number, loVal: number, hiVal: number): void;
    /**
     * Remove entry at slot using backward-shift deletion.
     * Maintains probe chain integrity without tombstones.
     *
     * @param slot - Slot index of the entry to remove.
     */
    removeAt(slot: number): void;
    delete(key: number): void;
    clear(): void;
    forEach(fn: (key: number, lo: number, hi: number) => void): void;
    clone(): BlockMaskMap;
    private _grow;
}
export { BlockMaskMap };
