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Benjamin Fan ed8a166ea9 fix(reference:api): Revert incorrect Example formatting (#367)
This PR reverts the incorrect lint/prettier changes applied to <Example> code in the reference Core API docs l by the husky pre-commit hook, the problem mentioned in Issue #333.

(These are just the changes for the Core API docs. Additional PRs will be filed for changes in the other reference, howtos, and guides documentation.)

Co-authored-by: Benjamin Fan <ben-git@swinglonga.com>
Reviewed-on: https://codeberg.org/freesewing/freesewing/pulls/367
Reviewed-by: Joost De Cock <joostdecock@noreply.codeberg.org>
Co-authored-by: Benjamin Fan <benjamesben@noreply.codeberg.org>
Co-committed-by: Benjamin Fan <benjamesben@noreply.codeberg.org>
2025-05-19 08:04:05 +02:00
..
readme.mdx fix(reference:api): Revert incorrect Example formatting (#367) 2025-05-19 08:04:05 +02:00

---
title: Path.angleAt()
---

The `Path.angleAt()` method returns the (tangent) angle of a path at a specific point.

If the given point is a sharp corner, this method prefers returning the angle directly before the corner.

If the given point does not lie (approximately) on the path, this method returns `false`.

## Signature

```js
number|false path.angleAt(Point point)
```

## Example

<Example caption="Example of the Path.angleAt() method">
```js
({ Point, points, Path, paths, snippets, Snippet, part }) => {

  points.A = new Point(45, 60)
  points.B = new Point(10, 30)
  points.BCp2 = new Point(40, 20)
  points.C = new Point(90, 30)
  points.CCp1 = new Point(50, -30)
  points.D = new Point(50, 80)
  points.DCp1 = new Point(70, 30)

  paths.demo = new Path()
    .move(points.D)
    .curve(points.DCp1, points.DCp1, points.C)
    .curve(points.CCp1, points.BCp2, points.B)
    .line(points.A)

  points.testPoint = paths.demo.shiftFractionAlong(0.55)
  snippets.point = new Snippet("notch", points.testPoint)

  let angle = paths.demo.angleAt(points.testPoint)
  //draw a tangent path
  paths.tangent = new Path()
    .move(points.testPoint.shift(angle, -30))
    .line(points.testPoint.shift(angle, 30))
    .attr("class", "lining dashed")

  return part
}
```
</Example>

## Notes

Keep in mind that calculations with Bézier curves are often approximations.