Documentation

markdown/dev/reference/api/utils/beamintersectscurve/en.md

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+---
+title: utils.beamIntersectsCurve()
+---
+
+The `utils.beamIntersectsCurve()` function finds the intersection between an endless
+line and a curve described by points
+`start`, `cp1`, `cp2, and `end\`.
+
+<Warning>
+
+This function can sometimes fail to find intersections in some curves
+due to a limitation in an underlying Bézier library.
+Please see [Bug #3367](https://github.com/freesewing/freesewing/issues/3367)
+for more information.
+
+</Warning>
+
+## Signature
+
+```js
+array | false utils.beamIntersectsCurve(
+  Point from,
+  Point to,
+  Point start,
+  Point cp1,
+  Point cp2,
+  Point end
+)
+```
+
+## Example
+
+<Example caption="A Utils.beamIntersectsCurve() example">
+```js
+({ Point, points, Path, paths, Snippet, snippets, getId, utils, part }) => {
+
+  points.A = new Point(10, 10)
+  points.Acp = new Point(10, 40)
+  points.B = new Point(110, 70)
+  points.Bcp = new Point(110, 40)
+  points.E = new Point(50, 14)
+  points.D = new Point(55, 16)
+  paths.curve = new Path()
+    .move(points.A)
+    .curve(points.Acp, points.Bcp, points.B)
+  paths.line = new Path().move(points.E).line(points.D)
+
+  for (let p of utils.beamIntersectsCurve(
+    points.D,
+    points.E,
+    points.A,
+    points.Acp,
+    points.Bcp,
+    points.B
+  )) {
+    snippets[getId()] = new Snippet("notch", p)
+  }
+
+  return part
+}
+```
+</Example>