Refactor (1)

packages/utils/src/vector.ts

@@ -0,0 +1,28 @@
+export type Vector = {
+  x: number;
+  y: number;
+};
+
+export type Radian = number;
+
+export const degree = (value: number) => ((value / 180) * Math.PI) as Radian;
+
+export const sub = (v1: Vector, v2: Vector) =>
+  ({
+    x: v1.x - v2.x,
+    y: v1.y - v2.y,
+  }) as Vector;
+
+export const add = (v1: Vector, v2: Vector) =>
+  ({
+    x: v1.x + v2.x,
+    y: v1.y + v2.y,
+  }) as Vector;
+
+export const theta = ({ x, y }: Vector) => Math.atan2(y, x) as Radian;
+
+export const rotate = ({ x, y }: Vector, rad: Radian) =>
+  ({
+    x: x * Math.cos(rad) - y * Math.sin(rad),
+    y: x * Math.sin(rad) + y * Math.cos(rad),
+  }) as Vector;