chore(music): play background music

src/constants/index.ts

@@ -1,3 +1,4 @@
+export * from './music'
 export * from './scenes'
 export * from './sounds'
 export * from './sprites'

src/constants/music.ts

@@ -0,0 +1,3 @@
+export enum Music {
+  Background = 'Background',
+}

src/gameobjects/index.ts

@@ -1,4 +1,5 @@
 export * from './bullet'
 export * from './enemy'
 export * from './health'
+export * from './music'
 export * from './player'

src/gameobjects/music.ts

@@ -0,0 +1,20 @@
+import type { AudioPlay } from 'kaplay'
+
+import { Music } from '../constants'
+
+let music: AudioPlay
+
+export function playMusic() {
+  if (!music) {
+    music = play(Music.Background, {
+      loop: true,
+      paused: true,
+    })
+    music.volume = 0.5
+  }
+  music.play()
+}
+
+export function stopMusic() {
+  music.stop()
+}

src/gameobjects/player.ts

@@ -1,5 +1,6 @@
 import { Scene, Sprite, Tag } from '../constants'
 import { addAttack, addCursorKeys } from '../events'
+import { stopMusic } from '../gameobjects'
 
 const HEALTH = 100
 
@@ -24,6 +25,7 @@ export function addPlayer(x = center().x, y = center().y) {
 
   player.onHurt(() => {
     if (player.hp() <= 0) {
+      stopMusic()
       go(Scene.Lose)
     }
   })

src/scenes/game.ts

@@ -1,10 +1,12 @@
 import { Scene } from '../constants'
-import { addEnemy, addHealth, addPlayer } from '../gameobjects'
+import { addEnemy, addHealth, addPlayer, playMusic } from '../gameobjects'
 import { outsideCoordinates } from '../helpers'
 
 scene(Scene.Game, () => {
   add([text('Press arrow keys', { width: width() / 2 }), pos(12, 12)])
 
+  playMusic()
+
   const player = addPlayer()
   addHealth(player)
 

src/scenes/preload.ts

@@ -1,4 +1,4 @@
-import { Scene, Sound, Sprite } from '../constants'
+import { Music, Scene, Sound, Sprite } from '../constants'
 
 scene(Scene.Preload, () => {
   const sprites = [
@@ -20,5 +20,11 @@ scene(Scene.Preload, () => {
     loadSound(name, src)
   })
 
+  const music = [[Music.Background, 'music/background.mp3']]
+
+  music.forEach(([name, src]) => {
+    loadMusic(name, src)
+  })
+
   go(Scene.Game)
 })