Add some more WebGl

frontend/src/scripts/math/rectangle.ts

@@ -0,0 +1,21 @@
+import { Typed } from '../transport/serializable';
+import { Vec2 } from './vec2';
+
+export class Rectangle extends Typed {
+  public constructor(
+    public topLeft: Vec2 = new Vec2(),
+    public size: Vec2 = new Vec2()
+  ) {
+    super();
+  }
+
+  public isInside(position: Vec2): boolean {
+    const translated = position.subtract(this.topLeft);
+    return (
+      0 <= translated.x &&
+      translated.x < this.size.x &&
+      0 <= translated.y &&
+      translated.y < this.size.y
+    );
+  }
+}