Merge pull request #3931 from freesewing/beamIntersectsCurve

utils.beamIntersectsCurve()

designs/examples/config/index.js

@@ -96,6 +96,7 @@ export default {
     'utils_beamsintersect',
     'utils_beamintersectsx',
     'utils_beamintersectsy',
+    'utils_beamintersectscurve',
     'utils_lineintersectscurve',
     'utils_curvesintersect',
     'utils_pointonbeam',

designs/examples/src/utils.mjs

@@ -84,6 +84,38 @@ export const utils_beamintersectsy = {
   },
 }
 
+export const utils_beamintersectscurve = {
+  name: 'examples.utils_beamintersectscurve',
+  draft: ({ Point, points, Path, paths, Snippet, snippets, utils, part }) => {
+    points.A = new Point(10, 10)
+    points.Acp = new Point(10, 40)
+    points.B = new Point(110, 10)
+    points.Bcp = new Point(110, 40)
+    points.E = new Point(45, 25)
+    points.D = new Point(65, 25)
+    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[part.getId()] = new Snippet('notch', p)
+    }
+
+    paths.help = new Path()
+      .move(new Point(0, 30))
+      .line(new Point(50, 30))
+      .attr('class', 'note dashed')
+
+    return part
+  },
+}
+
 export const utils_beamsintersect = {
   name: 'examples.utils_beamsintersect',
   draft: ({ Point, points, Path, paths, Snippet, snippets, utils, part }) => {

markdown/dev/reference/api/en.md

@@ -60,6 +60,7 @@ The following named exports are **utility methods**:
 | Named export | Description |
 | ------------ | ------------|
 | `beamIntersectsCircle`    | See the [beamIntersectsCircle](/reference/api/utils/beamintersectscircle) documentation |
+| `beamIntersectsCurve`     | See the [beamIntersectsCurve](/reference/api/utils/beamintersectscurve) documentation |
 | `beamIntersectsX`         | See the [beamIntersectsX](/reference/api/utils/beamintersectsx) documentation |
 | `beamIntersectsY`         | See the [beamIntersectsY](/reference/api/utils//beamintersectsy) documentation |
 | `beamsIntersect`          | See the [beamsIntersect](/reference/api/utils/beamsintersect) documentation |

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

@@ -0,0 +1,62 @@
+---
+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, 10)
+  points.Bcp = new Point(110, 40)
+  points.E = new Point(45, 25)
+  points.D = new Point(65, 25)
+  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>

packages/core/src/index.mjs

@@ -13,6 +13,7 @@ import {
   beamIntersectsX,
   beamIntersectsY,
   beamsIntersect,
+  beamIntersectsCurve,
   capitalize,
   circlesIntersect,
   curveEdge,
@@ -56,6 +57,7 @@ export {
   beamIntersectsX,
   beamIntersectsY,
   beamsIntersect,
+  beamIntersectsCurve,
   capitalize,
   circlesIntersect,
   curveEdge,

packages/core/src/utils.mjs

@@ -111,6 +111,24 @@ export function beamsIntersect(a1, a2, b1, b2) {
   }
 }
 
+/**
+ * Find the intersections between an endless line (beam) and a curve
+ *
+ *
+ * @param {Point} start - Start Point of the line
+ * @param {Point} end - End Point of the line
+ * @param {Point} from - Start Point of the curve
+ * @param {Point} cp1 - Control Point at the start of the curve
+ * @param {Point} cp2 - Control Point at the end of the curve
+ * @param {Point} to - End Point of the curve
+ * @return {Array} intersections - An array of Points at the intersections
+ */
+export function beamIntersectsCurve(start, end, from, cp1, cp2, to) {
+  let _start = new Point(start.x + (start.x - end.x) * 1000, start.y + (start.y - end.y) * 1000)
+  let _end = new Point(end.x + (end.x - start.x) * 1000, end.y + (end.y - start.y) * 1000)
+  return lineIntersectsCurve(_start, _end, from, cp1, cp2, to)
+}
+
 /**
  * Returns the string you pass with with the first character converted to uppercase
  *

packages/core/tests/utils.test.mjs

@@ -11,6 +11,7 @@ import {
   splitCurve,
   beamIntersectsX,
   beamIntersectsY,
+  beamIntersectsCurve,
   units,
   lineIntersectsCurve,
   curveIntersectsX,
@@ -70,6 +71,42 @@ describe('Utils', () => {
     expect(round(X.x)).to.equal(7.14)
     expect(round(X.y)).to.equal(40)
   })
+  it('Should find no intersections between a curve and a beam', () => {
+    let A = new Point(10, 10)
+    let Acp = new Point(10, 30)
+    let B = new Point(110, 10)
+    let Bcp = new Point(110, 30)
+    let E = new Point(10, 40)
+    let D = new Point(20, 40)
+
+    let hit = beamIntersectsCurve(E, D, A, Acp, Bcp, B)
+    expect(hit).to.equal(false)
+  })
+
+  it('Should find one intersections between a curve and a beam', () => {
+    let A = new Point(10, 10)
+    let Acp = new Point(10, 30)
+    let B = new Point(110, 10)
+    let Bcp = new Point(110, 30)
+    let E = new Point(50, 14)
+    let D = new Point(55, 16)
+
+    let hit = beamIntersectsCurve(E, D, A, Acp, Bcp, B)
+    expect(round(hit.x)).to.equal(75.79)
+    expect(round(hit.y)).to.equal(24.31)
+  })
+
+  it('Should find two intersections between a curve and a beam', () => {
+    let A = new Point(10, 10)
+    let Acp = new Point(10, 30)
+    let B = new Point(110, 10)
+    let Bcp = new Point(110, 30)
+    let E = new Point(0, 14)
+    let D = new Point(5, 15)
+
+    let hits = beamIntersectsCurve(E, D, A, Acp, Bcp, B)
+    expect(hits.length).to.equal(2)
+  })
 
   it("Should return false when two lines don't intersect", () => {
     let a = new Point(10, 20)