1 files changed, 87 insertions, 0 deletions
diff --git a/packages/utils/collision.test.ts b/packages/utils/collision.test.ts
new file mode 100644
index 0000000..744bea3
--- /dev/null
+++ b/packages/utils/collision.test.ts
@@ -0,0 +1,87 @@
+import type { Curve, Degrees, GlobalPoint } from "@excalidraw/math";
+import {
+  curve,
+  degreesToRadians,
+  lineSegment,
+  lineSegmentRotate,
+  pointFrom,
+  pointRotateDegs,
+} from "@excalidraw/math";
+import { pointOnCurve, pointOnPolyline } from "./collision";
+import type { Polyline } from "./geometry/shape";
+
+describe("point and curve", () => {
+  const c: Curve<GlobalPoint> = curve(
+    pointFrom(1.4, 1.65),
+    pointFrom(1.9, 7.9),
+    pointFrom(5.9, 1.65),
+    pointFrom(6.44, 4.84),
+  );
+
+  it("point on curve", () => {
+    expect(pointOnCurve(c[0], c, 10e-5)).toBe(true);
+    expect(pointOnCurve(c[3], c, 10e-5)).toBe(true);
+
+    expect(pointOnCurve(pointFrom(2, 4), c, 0.1)).toBe(true);
+    expect(pointOnCurve(pointFrom(4, 4.4), c, 0.1)).toBe(true);
+    expect(pointOnCurve(pointFrom(5.6, 3.85), c, 0.1)).toBe(true);
+
+    expect(pointOnCurve(pointFrom(5.6, 4), c, 0.1)).toBe(false);
+    expect(pointOnCurve(c[1], c, 0.1)).toBe(false);
+    expect(pointOnCurve(c[2], c, 0.1)).toBe(false);
+  });
+});
+
+describe("point and polylines", () => {
+  const polyline: Polyline<GlobalPoint> = [
+    lineSegment(pointFrom(1, 0), pointFrom(1, 2)),
+    lineSegment(pointFrom(1, 2), pointFrom(2, 2)),
+    lineSegment(pointFrom(2, 2), pointFrom(2, 1)),
+    lineSegment(pointFrom(2, 1), pointFrom(3, 1)),
+  ];
+
+  it("point on the line", () => {
+    expect(pointOnPolyline(pointFrom(1, 0), polyline)).toBe(true);
+    expect(pointOnPolyline(pointFrom(1, 2), polyline)).toBe(true);
+    expect(pointOnPolyline(pointFrom(2, 2), polyline)).toBe(true);
+    expect(pointOnPolyline(pointFrom(2, 1), polyline)).toBe(true);
+    expect(pointOnPolyline(pointFrom(3, 1), polyline)).toBe(true);
+
+    expect(pointOnPolyline(pointFrom(1, 1), polyline)).toBe(true);
+    expect(pointOnPolyline(pointFrom(2, 1.5), polyline)).toBe(true);
+    expect(pointOnPolyline(pointFrom(2.5, 1), polyline)).toBe(true);
+
+    expect(pointOnPolyline(pointFrom(0, 1), polyline)).toBe(false);
+    expect(pointOnPolyline(pointFrom(2.1, 1.5), polyline)).toBe(false);
+  });
+
+  it("point on the line with rotation", () => {
+    const truePoints = [
+      pointFrom(1, 0),
+      pointFrom(1, 2),
+      pointFrom(2, 2),
+      pointFrom(2, 1),
+      pointFrom(3, 1),
+    ];
+
+    truePoints.forEach((p) => {
+      const rotation = (Math.random() * 360) as Degrees;
+      const rotatedPoint = pointRotateDegs(p, pointFrom(0, 0), rotation);
+      const rotatedPolyline = polyline.map((line) =>
+        lineSegmentRotate(line, degreesToRadians(rotation), pointFrom(0, 0)),
+      );
+      expect(pointOnPolyline(rotatedPoint, rotatedPolyline)).toBe(true);
+    });
+
+    const falsePoints = [pointFrom(0, 1), pointFrom(2.1, 1.5)];
+
+    falsePoints.forEach((p) => {
+      const rotation = (Math.random() * 360) as Degrees;
+      const rotatedPoint = pointRotateDegs(p, pointFrom(0, 0), rotation);
+      const rotatedPolyline = polyline.map((line) =>
+        lineSegmentRotate(line, degreesToRadians(rotation), pointFrom(0, 0)),
+      );
+      expect(pointOnPolyline(rotatedPoint, rotatedPolyline)).toBe(false);
+    });
+  });
+});