@liammartens/svg-path-properties/lib/bezier.js

Calculate the length for an SVG path, to use it with node or a Canvas element

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Bezier = void 0;
const bezier_functions_1 = require("./bezier-functions");
class Bezier {
    constructor(ax, ay, bx, by, cx, cy, dx, dy) {
        this.getTotalLength = () => {
            return this.length;
        };
        this.getPointAtLength = (length) => {
            const xs = [this.a.x, this.b.x, this.c.x, this.d.x];
            const xy = [this.a.y, this.b.y, this.c.y, this.d.y];
            const t = (0, bezier_functions_1.t2length)(length, this.length, i => this.getArcLength(xs, xy, i));
            return this.getPoint(xs, xy, t);
        };
        this.getTangentAtLength = (length) => {
            const xs = [this.a.x, this.b.x, this.c.x, this.d.x];
            const xy = [this.a.y, this.b.y, this.c.y, this.d.y];
            const t = (0, bezier_functions_1.t2length)(length, this.length, i => this.getArcLength(xs, xy, i));
            const derivative = this.getDerivative(xs, xy, t);
            const mdl = Math.sqrt(derivative.x * derivative.x + derivative.y * derivative.y);
            let tangent;
            if (mdl > 0) {
                tangent = { x: derivative.x / mdl, y: derivative.y / mdl };
            }
            else {
                tangent = { x: 0, y: 0 };
            }
            return tangent;
        };
        this.getPropertiesAtLength = (length) => {
            const xs = [this.a.x, this.b.x, this.c.x, this.d.x];
            const xy = [this.a.y, this.b.y, this.c.y, this.d.y];
            const t = (0, bezier_functions_1.t2length)(length, this.length, i => this.getArcLength(xs, xy, i));
            const derivative = this.getDerivative(xs, xy, t);
            const mdl = Math.sqrt(derivative.x * derivative.x + derivative.y * derivative.y);
            let tangent;
            if (mdl > 0) {
                tangent = { x: derivative.x / mdl, y: derivative.y / mdl };
            }
            else {
                tangent = { x: 0, y: 0 };
            }
            const point = this.getPoint(xs, xy, t);
            return { x: point.x, y: point.y, tangentX: tangent.x, tangentY: tangent.y };
        };
        this.getC = () => {
            return this.c;
        };
        this.getD = () => {
            return this.d;
        };
        this.a = { x: ax, y: ay };
        this.b = { x: bx, y: by };
        this.c = { x: cx, y: cy };
        if (dx !== undefined && dy !== undefined) {
            this.getArcLength = bezier_functions_1.getCubicArcLength;
            this.getPoint = bezier_functions_1.cubicPoint;
            this.getDerivative = bezier_functions_1.cubicDerivative;
            this.d = { x: dx, y: dy };
        }
        else {
            this.getArcLength = bezier_functions_1.getQuadraticArcLength;
            this.getPoint = bezier_functions_1.quadraticPoint;
            this.getDerivative = bezier_functions_1.quadraticDerivative;
            this.d = { x: 0, y: 0 };
        }
        this.length = this.getArcLength([this.a.x, this.b.x, this.c.x, this.d.x], [this.a.y, this.b.y, this.c.y, this.d.y], 1);
    }
}
exports.Bezier = Bezier;