make npcs less annoying

common/entity.js

@@ -0,0 +1,23 @@
+class Entity {
+    constructor(game) {
+        let pos = { x: (Math.random() - 0.5) * (game ? game.width : 1000), y: (Math.random() - 0.5) * (game ? game.height : 1000) };
+        let vel = { x: 0, y: 0 };
+
+        this.pos = pos;
+        this.vel = vel;
+    }
+    bounce(game) {
+        let ent = this;
+        let { width, height } = game;
+
+        if (Math.abs(ent.pos.x) >= width / 2) {
+            ent.vel.x = (Math.abs(ent.vel.x) + 10) * -Math.sign(ent.pos.x);
+        }
+
+        if (Math.abs(ent.pos.y) >= height / 2) {
+            ent.vel.y = (Math.abs(ent.vel.y) + 10) * -Math.sign(ent.pos.y);
+        }
+    }
+}
+
+export default Entity;