curve-intersection

Bezier curve intersection algorithm and utilities.

Extracted from the Paper.js implementation of bezier clipping.

Installation

npm install --save curve-intersection

Usage

If your platform doesn't support es6 yet, you can require('curve-intersection/es3').

1import {curveIntersections} from 'curve-intersection';
2
3// coordinates of the control points
4let curves = [
5  [ 25.3, 21.4, -93.4, -180.5, 90.9, 177.2, -31, -15.8 ],
6  [ 26.9, -22.6, -196.3, 48.300000000000004, 193.4, -52, -21.8, 24 ]
7];
8
9let intersections = curveIntersections(curves[0], curves[1]);
10
11let canvas = document.createElement('canvas');
12canvas.width = 200;
13canvas.height = 200;
14document.body.appendChild(canvas);
15let ctx = canvas.getContext('2d');
16ctx.translate(100, 100);
17
18for (let curve of curves) {
19  ctx.beginPath();
20  ctx.moveTo(curve[0], curve[1]);
21  ctx.bezierCurveTo(curve[2], curve[3], curve[4], curve[5], curve[6], curve[7]);
22  ctx.closePath();
23  ctx.stroke();
24}
25
26for (let intersection of intersections) {
27  let [t1, p1, t2, p2] = intersection;
28  ctx.beginPath();
29  ctx.arc(p1[0], p1[1], 5, 0, 2 * Math.PI, false);
30  ctx.closePath();
31  ctx.fill();
32}