refactor: separate elements logic into a standalone package (#9285)

packages/utils/tests/geometry.test.ts

@@ -0,0 +1,163 @@
+import {
+  pointFrom,
+  lineSegment,
+  polygon,
+  pointOnLineSegment,
+  pointOnPolygon,
+  polygonIncludesPoint,
+  segmentsIntersectAt,
+} from "@excalidraw/math";
+
+import type {
+  GlobalPoint,
+  LineSegment,
+  Polygon,
+  Radians,
+} from "@excalidraw/math";
+
+import { pointInEllipse, pointOnEllipse, type Ellipse } from "../src/shape";
+
+describe("point and line", () => {
+  // const l: Line<GlobalPoint> = line(point(1, 0), point(1, 2));
+
+  // it("point on left or right of line", () => {
+  //   expect(pointLeftofLine(point(0, 1), l)).toBe(true);
+  //   expect(pointLeftofLine(point(1, 1), l)).toBe(false);
+  //   expect(pointLeftofLine(point(2, 1), l)).toBe(false);
+
+  //   expect(pointRightofLine(point(0, 1), l)).toBe(false);
+  //   expect(pointRightofLine(point(1, 1), l)).toBe(false);
+  //   expect(pointRightofLine(point(2, 1), l)).toBe(true);
+  // });
+
+  const s: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(1, 0),
+    pointFrom(1, 2),
+  );
+
+  it("point on the line", () => {
+    expect(pointOnLineSegment(pointFrom(0, 1), s)).toBe(false);
+    expect(pointOnLineSegment(pointFrom(1, 1), s, 0)).toBe(true);
+    expect(pointOnLineSegment(pointFrom(2, 1), s)).toBe(false);
+  });
+});
+
+describe("point and polygon", () => {
+  const poly: Polygon<GlobalPoint> = polygon(
+    pointFrom(10, 10),
+    pointFrom(50, 10),
+    pointFrom(50, 50),
+    pointFrom(10, 50),
+  );
+
+  it("point on polygon", () => {
+    expect(pointOnPolygon(pointFrom(30, 10), poly)).toBe(true);
+    expect(pointOnPolygon(pointFrom(50, 30), poly)).toBe(true);
+    expect(pointOnPolygon(pointFrom(30, 50), poly)).toBe(true);
+    expect(pointOnPolygon(pointFrom(10, 30), poly)).toBe(true);
+    expect(pointOnPolygon(pointFrom(30, 30), poly)).toBe(false);
+    expect(pointOnPolygon(pointFrom(30, 70), poly)).toBe(false);
+  });
+
+  it("point in polygon", () => {
+    const poly: Polygon<GlobalPoint> = polygon(
+      pointFrom(0, 0),
+      pointFrom(2, 0),
+      pointFrom(2, 2),
+      pointFrom(0, 2),
+    );
+    expect(polygonIncludesPoint(pointFrom(1, 1), poly)).toBe(true);
+    expect(polygonIncludesPoint(pointFrom(3, 3), poly)).toBe(false);
+  });
+});
+
+describe("point and ellipse", () => {
+  const ellipse: Ellipse<GlobalPoint> = {
+    center: pointFrom(0, 0),
+    angle: 0 as Radians,
+    halfWidth: 2,
+    halfHeight: 1,
+  };
+
+  it("point on ellipse", () => {
+    [
+      pointFrom(0, 1),
+      pointFrom(0, -1),
+      pointFrom(2, 0),
+      pointFrom(-2, 0),
+    ].forEach((p) => {
+      expect(pointOnEllipse(p, ellipse)).toBe(true);
+    });
+    expect(pointOnEllipse(pointFrom(-1.4, 0.7), ellipse, 0.1)).toBe(true);
+    expect(pointOnEllipse(pointFrom(-1.4, 0.71), ellipse, 0.01)).toBe(true);
+
+    expect(pointOnEllipse(pointFrom(1.4, 0.7), ellipse, 0.1)).toBe(true);
+    expect(pointOnEllipse(pointFrom(1.4, 0.71), ellipse, 0.01)).toBe(true);
+
+    expect(pointOnEllipse(pointFrom(1, -0.86), ellipse, 0.1)).toBe(true);
+    expect(pointOnEllipse(pointFrom(1, -0.86), ellipse, 0.01)).toBe(true);
+
+    expect(pointOnEllipse(pointFrom(-1, -0.86), ellipse, 0.1)).toBe(true);
+    expect(pointOnEllipse(pointFrom(-1, -0.86), ellipse, 0.01)).toBe(true);
+
+    expect(pointOnEllipse(pointFrom(-1, 0.8), ellipse)).toBe(false);
+    expect(pointOnEllipse(pointFrom(1, -0.8), ellipse)).toBe(false);
+  });
+
+  it("point in ellipse", () => {
+    [
+      pointFrom(0, 1),
+      pointFrom(0, -1),
+      pointFrom(2, 0),
+      pointFrom(-2, 0),
+    ].forEach((p) => {
+      expect(pointInEllipse(p, ellipse)).toBe(true);
+    });
+
+    expect(pointInEllipse(pointFrom(-1, 0.8), ellipse)).toBe(true);
+    expect(pointInEllipse(pointFrom(1, -0.8), ellipse)).toBe(true);
+
+    expect(pointInEllipse(pointFrom(-1, 1), ellipse)).toBe(false);
+    expect(pointInEllipse(pointFrom(-1.4, 0.8), ellipse)).toBe(false);
+  });
+});
+
+describe("line and line", () => {
+  const lineA: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(1, 4),
+    pointFrom(3, 4),
+  );
+  const lineB: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(2, 1),
+    pointFrom(2, 7),
+  );
+  const lineC: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(1, 8),
+    pointFrom(3, 8),
+  );
+  const lineD: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(1, 8),
+    pointFrom(3, 8),
+  );
+  const lineE: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(1, 9),
+    pointFrom(3, 9),
+  );
+  const lineF: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(1, 2),
+    pointFrom(3, 4),
+  );
+  const lineG: LineSegment<GlobalPoint> = lineSegment(
+    pointFrom(0, 1),
+    pointFrom(2, 3),
+  );
+
+  it("intersection", () => {
+    expect(segmentsIntersectAt(lineA, lineB)).toEqual([2, 4]);
+    expect(segmentsIntersectAt(lineA, lineC)).toBe(null);
+    expect(segmentsIntersectAt(lineB, lineC)).toBe(null);
+    expect(segmentsIntersectAt(lineC, lineD)).toBe(null); // Line overlapping line is not intersection!
+    expect(segmentsIntersectAt(lineE, lineD)).toBe(null);
+    expect(segmentsIntersectAt(lineF, lineG)).toBe(null);
+  });
+});