import type { ViewerApi } from '../../core/types/viewer-api';
import type { ViewBox } from '../../core/types/viewer';
export declare const isViewBoxEqual: (a: ViewBox | null | undefined, b: ViewBox, tolerance?: number) => boolean;
type PanDeps = {
    now: () => number;
    requestAnimationFrame?: (callback: FrameRequestCallback) => number;
    cancelAnimationFrame?: (handle: number) => void;
};
/**
 * Moves the viewer to a chapter's framing, animating only when that framing is
 * expressed in the coordinate space the viewer is already showing.
 *
 * A viewBox is in canvas pixels, so tweening one across a source change
 * interpolates numbers that describe two different images — the camera sweeps
 * through positions meaningful on neither. Callers pass `sourceChanged` for any
 * transition that swapped the Manifest or the Canvas underneath, and the target
 * is applied in one step instead.
 */
export declare const panToViewBox: (viewer: ViewerApi, targetViewBox: ViewBox, sourceChanged: boolean, deps: PanDeps) => (() => void) | null;
export {};