From 68c0fca1249fe9108aec54c7d1c1eacd73a15fde Mon Sep 17 00:00:00 2001
From: Wouter van Wageningen <wouter.vdub@yahoo.com>
Date: Fri, 28 Apr 2023 16:42:35 +0000
Subject: [PATCH] Code and tests

---
 packages/core/src/index.mjs        |  2 ++
 packages/core/src/utils.mjs        | 19 +++++++++++++++
 packages/core/tests/utils.test.mjs | 37 ++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+)

diff --git a/packages/core/src/index.mjs b/packages/core/src/index.mjs
index 38657c84c0d..fe75b9f5ad1 100644
--- a/packages/core/src/index.mjs
+++ b/packages/core/src/index.mjs
@@ -13,6 +13,7 @@ import {
   beamIntersectsX,
   beamIntersectsY,
   beamsIntersect,
+  beamIntersectsCurve,
   capitalize,
   circlesIntersect,
   curveEdge,
@@ -55,6 +56,7 @@ export {
   beamIntersectsX,
   beamIntersectsY,
   beamsIntersect,
+  beamIntersectsCurve,
   capitalize,
   circlesIntersect,
   curveEdge,
diff --git a/packages/core/src/utils.mjs b/packages/core/src/utils.mjs
index aea6af3d686..11b49f8b5f8 100644
--- a/packages/core/src/utils.mjs
+++ b/packages/core/src/utils.mjs
@@ -111,6 +111,25 @@ 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)
+  console.log({ _start: _start, _end: _end })
+  return lineIntersectsCurve(_start, _end, from, cp1, cp2, to)
+}
+
 /**
  * Returns the string you pass with with the first character converted to uppercase
  *
diff --git a/packages/core/tests/utils.test.mjs b/packages/core/tests/utils.test.mjs
index bd0817f0ee6..cc5b88a78b7 100644
--- a/packages/core/tests/utils.test.mjs
+++ b/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)