finally

src/page/background/vec2.ts

@@ -0,0 +1,17 @@
+export class Vec2 {
+  public static readonly Zero = new Vec2(0, 0);
+
+  public constructor(public readonly x: number, public readonly y: number) {}
+
+  public add(other: Vec2): Vec2 {
+    return new Vec2(this.x + other.x, this.y + other.y);
+  }
+
+  public subtract(other: Vec2): Vec2 {
+    return new Vec2(this.x - other.x, this.y - other.y);
+  }
+
+  public multiply(other: Vec2): Vec2 {
+    return new Vec2(this.x * other.x, this.y * other.y);
+  }
+}