import type { Group } from '../shapes/Group';
export interface CacheEntry {
    canvas: HTMLCanvasElement;
    ctx: CanvasRenderingContext2D;
    width: number;
    height: number;
}
/** Offscreen bitmap cache for static subtrees. */
export declare class LayerCache {
    private entries;
    get(group: Group): CacheEntry | undefined;
    set(group: Group, entry: CacheEntry): void;
    invalidate(nodeId: string): void;
    invalidateSubtree(group: Group): void;
    isValid(group: Group): boolean;
    clear(): void;
    destroy(): void;
}