import type { UIPlaneElement, UIPointElement } from "../../miscellaneous/shared";
import { UISingleParameterConstraint } from "../UISingleParameterConstraint/UISingleParameterConstraint";
import type { UIVerticalDistanceConstraintOptions } from "./UIVerticalDistanceConstraint.Internal";
/** Maintains vertical distance between elements with configurable anchors */
export declare class UIVerticalDistanceConstraint extends UISingleParameterConstraint {
    readonly a: UIPointElement | UIPlaneElement;
    readonly b: UIPointElement | UIPlaneElement;
    protected readonly constraint: number;
    private anchorAInternal;
    private anchorBInternal;
    private distanceInternal;
    /**
     * @param a First element
     * @param b Second element
     * @param options Distance configuration
     */
    constructor(a: UIPointElement | UIPlaneElement, b: UIPointElement | UIPlaneElement, options?: Partial<UIVerticalDistanceConstraintOptions>);
    /** Current distance in world units */
    get distance(): number;
    /** Anchor on element A (0 = bottom, 0.5 = center, 1 = top) */
    get anchorA(): number;
    /** Anchor on element B (0 = bottom, 0.5 = center, 1 = top) */
    get anchorB(): number;
    /** Updates distance */
    set distance(value: number);
    /** Updates anchor on element A */
    set anchorA(value: number);
    /** Updates anchor on element B */
    set anchorB(value: number);
    /** Builds constraint expression for distance between anchored positions */
    private buildLHS;
}