feat(core): add Point type and distance calculation function

Added the Point type, leveraging the Vector2 structure, to represent 2D points in the swiperia-core package. Also implemented a function to calculate the Euclidean distance between two points, complete with unit tests to validate functionality.

packages/swiperia-core/src/lib/point/Point.type.ts

@@ -0,0 +1,6 @@
+import type { Vector2 } from "../vector2/Vector2.type";
+
+/**
+ * Represents a 2D point or coordinate.
+ */
+export type Point = Vector2;

packages/swiperia-core/src/lib/point/distance.spec.ts

@@ -0,0 +1,22 @@
+import { Point } from './Point.type';
+import { distance } from './distance';
+
+describe('distance', () => {
+  it('should calculate the distance between two points', () => {
+    const a: Point = [0, 0];
+    const b: Point = [3, 4];
+    expect(distance(a, b)).toEqual(5);
+  });
+
+  it('should handle negative coordinates', () => {
+    const a: Point = [-2, 3];
+    const b: Point = [1, -1];
+    expect(distance(a, b)).toEqual(5);
+  });
+
+  it('should return 0 for the same point', () => {
+    const a: Point = [5, 5];
+    const b: Point = [5, 5];
+    expect(distance(a, b)).toEqual(0);
+  });
+});

packages/swiperia-core/src/lib/point/distance.ts

@@ -0,0 +1,16 @@
+import type { Point } from './Point.type';
+
+/**
+ * Calculates the Euclidean distance between two points.
+ *
+ * @param a - The first point.
+ * @param b - The second point.
+ * @returns The Euclidean distance between the two points.
+ */
+export const distance = (a: Point, b: Point): number => {
+  const [ax, ay] = a;
+  const [bx, by] = b;
+  const dx = ax - bx;
+  const dy = ay - by;
+  return Math.sqrt(dx * dx + dy * dy);
+};

packages/swiperia-core/src/lib/point/index.ts

@@ -0,0 +1,2 @@
+export type { Point } from './Point.type';
+export { distance } from './distance';