import { VecN } from '@holotope/core';
import type { ConstraintBlock4 } from './constraint-block4.js';
import type { ConstraintParticipant4 } from './constraint-row4.js';
import { RigidBody4 } from './rigid-body4.js';
export interface DirectionConstraintBlock4Options {
    readonly id: string;
    readonly participantA: ConstraintParticipant4;
    readonly participantB: ConstraintParticipant4;
    /** Current oriented world direction carried by participant A. */
    readonly directionA: VecN | ArrayLike<number>;
    /** Current oriented world direction carried by participant B. */
    readonly directionB: VecN | ArrayLike<number>;
    /** Previous tangent frame, projected forward for coordinate continuity. */
    readonly previousTangentBasis?: readonly VecN[];
    /** Guard on `1 + directionA dot directionB`. Default 1e-10. */
    readonly antipodalTolerance?: number;
    /** Rank threshold used while transporting the tangent frame. Default 1e-10. */
    readonly frameTolerance?: number;
}
export type DirectionConstraintEvaluation4 = {
    readonly status: 'regular';
    readonly block: ConstraintBlock4;
    readonly directionA: VecN;
    readonly directionB: VecN;
    readonly referenceDirection: VecN;
    readonly tangentBasis: readonly [VecN, VecN, VecN];
    readonly positionError: Float64Array;
    readonly antipodalGuard: number;
} | {
    readonly status: 'antipodal';
    readonly directionA: VecN;
    readonly directionB: VecN;
    readonly antipodalGuard: number;
};
/**
 * Builds the three-row quotient coordinate which preserves one oriented R4
 * material direction while leaving its SO(3) stabilizer free.
 */
export declare function directionConstraintBlock4(options: DirectionConstraintBlock4Options): DirectionConstraintEvaluation4;
export type DirectionJoint4Options = {
    readonly id: string;
    readonly bodyA: RigidBody4;
    readonly localDirectionA: VecN | ArrayLike<number>;
    readonly bodyB: RigidBody4;
    readonly localDirectionB: VecN | ArrayLike<number>;
    readonly antipodalTolerance?: number;
    readonly frameTolerance?: number;
} | {
    readonly id: string;
    readonly bodyA: RigidBody4;
    readonly localDirectionA: VecN | ArrayLike<number>;
    readonly bodyB?: null;
    readonly worldDirectionB: VecN | ArrayLike<number>;
    readonly antipodalTolerance?: number;
    readonly frameTolerance?: number;
};
/** Persistent local-direction binding with a transported three-coordinate frame. */
export declare class DirectionJoint4 {
    readonly id: string;
    readonly bodyA: RigidBody4;
    readonly localDirectionA: VecN;
    readonly bodyB: RigidBody4 | null;
    readonly directionB: VecN;
    readonly antipodalTolerance: number;
    readonly frameTolerance: number;
    private previousTangentBasis;
    constructor(options: DirectionJoint4Options);
    worldDirectionA(): VecN;
    worldDirectionB(): VecN;
    constraint(): DirectionConstraintEvaluation4;
    resetFrame(): void;
}
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