refactor(gameobjects): improve star

src/gameobjects/index.ts

@@ -2,4 +2,5 @@ export * from './buttons';
 export * from './keys';
 export * from './pause';
 export * from './score';
+export * from './star';
 export * from './timer';

src/gameobjects/keys.ts

@@ -1,15 +1,9 @@
 import type { AudioPlay } from 'kaboom';
 
-import {
-  DirectionKey,
-  directions,
-  Key,
-  Sound,
-  Sprite,
-  Tag,
-} from '../constants';
+import { DirectionKey, directions, Key, Sound, Tag } from '../constants';
 import { getPosition } from '../helpers';
 import { addScore } from './score';
+import { addStar } from './star';
 
 // const LONG_PRESS_MILLISECONDS = 500;
 
@@ -58,14 +52,7 @@ export function addKeys() {
   (directions as DirectionKey[]).forEach((key) => {
     onCollideUpdate(key, Tag.direction, () => {
       if (isKeyPressed(key)) {
-        add([
-          sprite(Sprite.star),
-          pos(center()),
-          anchor('center'),
-          scale(0.4),
-          lifespan(0.03, { fade: 0.5 }),
-          opacity(1),
-        ]);
+        addStar();
         incrementScore();
       }
     });

src/gameobjects/star.ts

@@ -0,0 +1,39 @@
+import type { GameObj, ScaleComp } from 'kaboom';
+
+import { Sprite } from '../constants';
+
+export function addStar(position = center()) {
+  const kaboom = add([pos(position), stay()]);
+
+  const speed = 1 * 5;
+  const size = 1;
+
+  const ka = kaboom.add([
+    sprite(Sprite.star),
+    scale(0),
+    anchor('center'),
+    timer(),
+    opacity(0.5),
+  ]);
+
+  ka.wait(0.4 / speed, () => ka.use(boom(speed, size)));
+  ka.onDestroy(() => kaboom.destroy());
+
+  return kaboom;
+}
+
+function boom(speed: number = 2, size: number = 1) {
+  let time = 0;
+
+  return {
+    require: ['scale'],
+    update(this: GameObj<ScaleComp>) {
+      const s = Math.sin(time * speed) * size;
+      if (s < 0) {
+        this.destroy();
+      }
+      this.scale = vec2(s);
+      time += dt();
+    },
+  };
+}