toosoon-utils/lib/extras/curves/SplineCurve3.js

Utility functions & classes

import { Vector3 } from '../geometry';
import CatmullRomCurve3 from './CatmullRomCurve3';
import Curve from './Curve';
/**
 * Utility class for manipulating 3D splines
 *
 * @exports
 * @class SplineCurve3
 * @extends Curve
 */
export default class SplineCurve3 extends Curve {
    type = 'SplineCurve3';
    /**
     * Array of points defining the curve
     */
    points = [];
    /**
     * @param {Point3[]} [points] Array of points defining the curve
     */
    constructor(points = []) {
        super();
        this.points = points;
    }
    /**
     * Interpolate a point on this curve
     *
     * @param {number} t Normalized time value to interpolate
     * @returns {Vector3} Interpolated coordinates on this curve
     */
    getPoint(t) {
        const points = this.points;
        const p = (points.length - 1) * t;
        const index = Math.floor(p);
        const weight = p - index;
        const p1 = points[index === 0 ? index : index - 1];
        const cp1 = points[index];
        const cp2 = points[index > points.length - 2 ? points.length - 1 : index + 1];
        const p2 = points[index > points.length - 3 ? points.length - 1 : index + 2];
        return new Vector3(...CatmullRomCurve3.interpolate(weight, ...p1, ...cp1, ...cp2, ...p2));
    }
}