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

Utility functions & classes

import { Vector2 } from '../geometry';
import LineCurve from './LineCurve';
import Curve from './Curve';
/**
 * Utility class for manipulating polylines
 *
 * @exports
 * @class PolylineCurve
 * @extends Curve
 */
export default class PolylineCurve extends Curve {
    type = 'PolylineCurve';
    /**
     * Array of points defining the curve
     */
    points = [];
    /**
     * @param {Point2[]} [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 {Vector2} 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 p2 = points[index];
        return new Vector2(...LineCurve.interpolate(weight, ...p1, ...p2));
    }
}