import { type TPlacement } from './resolve-placement';
/**
 * Computes popover position from trigger rect and viewport, flipping to
 * the side with more space when needed. Re-runs on scroll/resize.
 *
 * `gap` and `crossAxisShift` are pre-resolved to pixels by the
 * caller (see `resolveCssLengthToPixels`), so this function stays purely
 * numeric.
 */
export declare function computeFallbackPosition({ triggerRect, popoverEl, placement, viewport, gap, crossAxisShift, }: {
    triggerRect: DOMRect;
    popoverEl: HTMLElement;
    placement: TPlacement;
    viewport: {
        width: number;
        height: number;
    };
    gap: number;
    crossAxisShift: {
        value: number;
        direction: 'forwards' | 'backwards';
    };
}): {
    top: number;
    left: number;
};