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

title
utils.curveIntersectsX()

The utils.curveIntersectsX() function finds the point(s) where a curve intersects a given X-value.

Signature

array | Point | false utils.curveIntersectsX(
  Point start, 
  Point cp1,
  Point cp2,
  Point end,
  float x)

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, part }) => {

points.start = new Point(10, 15) points.cp1 = new Point(80, 10) points.cp2 = new Point(-50, 80) points.end = new Point(110, 70)

paths.curve = new Path() .move(points.start) .curve(points.cp1, points.cp2, points.end)

for (let x of [30, 40]) { points["from" + x] = new Point(x, 10) points["to" + x] = new Point(x, 80) paths["line" + x] = new Path() .move(points["from" + x]) .line(points["to" + x]) .addClass("lining dashed") }

snippets.i40 = new Snippet( "notch", utils.curveIntersectsX(points.start, points.cp1, points.cp2, points.end, 40) )

for (let p of utils.curveIntersectsX( points.start, points.cp1, points.cp2, points.end, 30 )) snippets[p.y] = new Snippet("notch", p)

return part }

</Example>


## Notes

This is a low-level (and faster) variant
of [`Path.intersectsX()`](/reference/api/path/intersectsx).
Instead of a path, you describe a single curve by passing the four
points that describes it.