import type { Point3 } from '../../types';
import { Vector3 } from '../geometry';
import Curve from './Curve';
/**
 * Utility class for manipulating 3D lines
 *
 * @exports
 * @class LineCurve3
 * @extends Curve<Vector3>
 */
export default class LineCurve3 extends Curve<Vector3> {
    readonly type: string;
    /**
     * X-axis coordinate of the start point
     */
    x1: number;
    /**
     * Y-axis coordinate of the start point
     */
    y1: number;
    /**
     * Z-axis coordinate of the start point
     */
    z1: number;
    /**
     * X-axis coordinate of the end point
     */
    x2: number;
    /**
     * Y-axis coordinate of the end point
     */
    y2: number;
    /**
     * Z-axis coordinate of the end point
     */
    z2: number;
    /**
     * @param {number} x1 X-axis coordinate of the start point
     * @param {number} y1 Y-axis coordinate of the start point
     * @param {number} z1 Z-axis coordinate of the start point
     * @param {number} x2 X-axis coordinate of the end point
     * @param {number} y2 Y-axis coordinate of the end point
     * @param {number} z2 Z-axis coordinate of the end point
     */
    constructor(x1: number, y1: number, z1: number, x2: number, y2: number, z2: number);
    /**
     * Interpolate a point on this curve
     *
     * @param {number} t Normalized time value to interpolate
     * @returns {Vector3} Interpolated coordinates on this curve
     */
    getPoint(t: number): Vector3;
    /**
     * Interpolate a point on this curve
     *
     * @param {number} u Normalized position value to interpolate
     * @returns {Vector3} Interpolated coordinates on this curve
     */
    getPointAt(u: number): Vector3;
    /**
     * Compute an unit vector tangent for a given normalized time value
     *
     * @param {number} t Normalized time value
     * @returns {Vector3} Tangent vector
     */
    getTangent(t?: number): Vector3;
    /**
     * Compute an unit vector tangent for a given normalized position value
     *
     * @param {number} u Normalized position value
     * @returns {Vector3} Tangent vector
     */
    getTangentAt(u?: number): Vector3;
    /**
     * Interpolate a point on a 3D line
     *
     * @param {number} t  Normalized time value to interpolate
     * @param {number} x1 X-axis coordinate of the start point
     * @param {number} y1 Y-axis coordinate of the start point
     * @param {number} z1 Z-axis coordinate of the start point
     * @param {number} x2 X-axis coordinate of the end point
     * @param {number} y2 Y-axis coordinate of the end point
     * @param {number} z2 Z-axis coordinate of the end point
     * @returns {Point3} Interpolated coordinates on the line
     */
    static interpolate(t: number, x1: number, y1: number, z1: number, x2: number, y2: number, z2: number): Point3;
}