import * as THREE from 'three/webgpu';
export type GLTFCurveCoordinate = readonly [x: number, y: number, z: number];
export interface GLTFBezierPoint {
    co: GLTFCurveCoordinate;
    handle_left: GLTFCurveCoordinate;
    handle_right: GLTFCurveCoordinate;
}
export interface GLTFNURBSPoint {
    co: GLTFCurveCoordinate;
    w?: number;
}
export interface GLTFPolyPoint {
    co: GLTFCurveCoordinate;
}
interface GLTFCurveSplineBase {
    resolution_u: number;
    use_cyclic_u: boolean;
}
export interface GLTFBezierSpline extends GLTFCurveSplineBase {
    type: 'BEZIER';
    points: GLTFBezierPoint[];
}
export interface GLTFNURBSSpline extends GLTFCurveSplineBase {
    type: 'NURBS';
    order_u: number;
    knots?: number[];
    points: GLTFNURBSPoint[];
}
export interface GLTFPolySpline extends GLTFCurveSplineBase {
    type: 'POLY';
    points: GLTFPolyPoint[];
}
export type GLTFCurveSpline = GLTFBezierSpline | GLTFNURBSSpline | GLTFPolySpline;
export interface GLTFCurveData {
    splines: [GLTFCurveSpline, ...GLTFCurveSpline[]];
}
export interface GLTFCurveNodeExtensions {
    UTSUBO_curve_extension?: GLTFCurveData;
}
export interface GLTFCurveNodeDefinition {
    name?: string;
    children?: number[];
    extensions?: GLTFCurveNodeExtensions;
    matrix?: THREE.Matrix4Tuple;
    translation?: THREE.Vector3Tuple;
    rotation?: THREE.QuaternionTuple;
    scale?: THREE.Vector3Tuple;
}
export interface GLTFCurveNodeWithData extends GLTFCurveNodeDefinition {
    extensions: GLTFCurveNodeExtensions & {
        UTSUBO_curve_extension: GLTFCurveData;
    };
}
export interface GLTFCurveAssociation {
    nodes?: number;
}
export interface GLTFCurveAssociationStore {
    has(object: THREE.Object3D): boolean;
    set(object: THREE.Object3D, association: GLTFCurveAssociation): unknown;
    get(object: THREE.Object3D): GLTFCurveAssociation | undefined;
}
export interface GLTFCurveParser {
    json: {
        nodes?: GLTFCurveNodeDefinition[];
    };
    associations: GLTFCurveAssociationStore;
    getDependencies(type: 'node'): Promise<THREE.Object3D[]>;
}
export interface GLTFCurveResult {
    scene: Pick<THREE.Object3D, 'add'>;
}
export type GLTFCurveObject = THREE.Line<THREE.BufferGeometry, THREE.LineBasicMaterial>;
declare class GLTFCurveExtension {
    readonly parser: GLTFCurveParser;
    readonly name = "UTSUBO_curve_extension";
    constructor(parser: GLTFCurveParser);
    /** The loader ignores the fulfillment value; direct callers historically receive created curves. */
    afterRoot(result: GLTFCurveResult): Promise<GLTFCurveObject[]> | null;
    /** Compatibility overload for Three.js' narrower `GLTFLoaderPlugin.afterRoot` contract. */
    afterRoot(result: GLTFCurveResult): Promise<void> | null;
    createCurves(nodeDefs: GLTFCurveNodeDefinition[], result: GLTFCurveResult, loadedNodes: THREE.Object3D[]): Promise<GLTFCurveObject[]>;
    private hasCurveExtension;
    createCurve(nodeDef: GLTFCurveNodeWithData, result: GLTFCurveResult, nodeIndex: number, loadedNode: THREE.Object3D | undefined): Promise<GLTFCurveObject>;
    convertBlenderToThreeCoordinates(coord: GLTFCurveCoordinate): THREE.Vector3;
    applyNodeTransform(object: THREE.Object3D, nodeDef: GLTFCurveNodeDefinition): void;
    replaceCurveInScene(result: GLTFCurveResult, curveObject: GLTFCurveObject, originalNode: THREE.Object3D | undefined): void;
    createNURBSCurvePath(nurbsData: GLTFNURBSSpline): THREE.CurvePath<THREE.Vector3>;
    generateKnots(numPoints: number, degree: number, cyclic: boolean): number[];
}
export { GLTFCurveExtension };