freesewing/markdown/dev/reference/api/utils/curvesintersect/en.md

title
utils.curvesIntersect()

The utils.curvesIntersect() function finds the intersections between two curves described by 4 points each.

This function can sometimes fail to find intersections in some curves due to a limitation in an underlying Bézier library. Please see Bug #3367 for more information.

Signature

array | Point | false utils.curvesIntersect(
  Point startA,
  Point Cp1A,
  Point Cp2A,
  Point endA,
  Point startB,
  Point Cp1B,
  Point Cp2B,
  Point endB)

This returns false if no intersections are found, a Point object if a single intersection is found, and an array of Point objects if multiple intersections are found.

Example

```js ({ Point, points, Path, paths, Snippet, snippets, utils, getId, part }) => {

points.A = new Point(10, 10) points.Acp = new Point(310, 40) points.B = new Point(110, 70) points.Bcp = new Point(-210, 40)

points.C = new Point(20, -5) points.Ccp = new Point(60, 300) points.D = new Point(100, 85) points.Dcp = new Point(70, -220) paths.curveA = new Path() .move(points.A) .curve(points.Acp, points.Bcp, points.B) paths.curveB = new Path() .move(points.C) .curve(points.Ccp, points.Dcp, points.D)

const intersections = utils.curvesIntersect( points.A, points.Acp, points.Bcp, points.B, points.C, points.Ccp, points.Dcp, points.D )

if (intersections) { if (intersections instanceof Array) { for (const p of intersections) snippets[getId()] = new Snippet('notch', p) } else { snippets[getId()] = new Snippet('notch', intersections) } }

return part }

</Example>