09 · 街机射击：敌人波次与碰撞

目标：定时刷敌；用 overlap 做子弹×敌人得分与玩家×敌人失败；对照阶段一手写 AABB。
前置：08 · 玩家移动与射击

1. 敌人 Group + 定时器

private enemies!: Phaser.Physics.Arcade.Group
private score = 0
private gameOver = false

create() {
  this.enemies = this.physics.add.group({
    classType: Phaser.Physics.Arcade.Image,
    maxSize: 30,
  })

  this.time.addEvent({
    delay: 700,
    loop: true,
    callback: () => this.spawnEnemy(),
  })

  // 见下：overlap
}

private spawnEnemy() {
  if (this.gameOver) return
  const x = Phaser.Math.Between(30, 450)
  const e = this.enemies.get(x, -20, 'enemy') as Phaser.Physics.Arcade.Image | null
  if (!e) return
  e.setActive(true).setVisible(true)
  e.enableBody(true, x, -20, true, true)
  e.setVelocity(0, Phaser.Math.Between(80, 140))
}

对照 05：spawnTimer -= fixedDt ↔ time.addEvent({ delay, loop })。

2. overlap ≈ 引擎版 hit()

this.physics.add.overlap(
  this.bullets,
  this.enemies,
  (b, e) => this.onHitEnemy(
    b as Phaser.Physics.Arcade.Image,
    e as Phaser.Physics.Arcade.Image,
  ),
  undefined,
  this,
)

this.physics.add.overlap(
  this.player,
  this.enemies,
  () => this.onPlayerHit(),
  undefined,
  this,
)

private onHitEnemy(
  bullet: Phaser.Physics.Arcade.Image,
  enemy: Phaser.Physics.Arcade.Image,
) {
  this.bullets.killAndHide(bullet)
  bullet.body?.stop()
  this.enemies.killAndHide(enemy)
  enemy.body?.stop()
  this.score += 1
}

private onPlayerHit() {
  this.gameOver = true
  this.physics.pause()
}

阶段一	Phaser
双重 for + `hit(a,b)`	`physics.add.overlap`
`splice` 删除	`killAndHide` / `disableBody`
`score += 1`	同左

collider 会推挤分离；射击命中用 overlap（只回调，不弹开）更合适。

3. 出屏敌人也要回收

在 update 末尾：

this.enemies.children.each((child) => {
  const e = child as Phaser.Physics.Arcade.Image
  if (!e.active) return true
  if (e.y > 660) {
    this.enemies.killAndHide(e)
    e.body?.stop()
  }
  return true
})

漏回收 → Group 占满 maxSize → 再也刷不出怪，像「游戏坏了」。

4. gameOver 时停输入

update(_t: number, delta: number) {
  if (this.gameOver) return
  // 移动、射击、回收……
}

HUD 与 R 重启放 10。

验收清单

[ ] 约每 0.7s 顶部刷出一个红敌机并下落
[ ] 子弹打中敌人：双方消失，分数逻辑 +1（可先 console.log(score)）
[ ] 敌人碰玩家：进入 gameOver，物理暂停
[ ] 敌机飞出底边被回收；长时间游玩 Group 不堵死
[ ] 能向别人讲清 overlap 与阶段一 AABB 的对应关系

→ 10 · 街机射击：完整一关验收

09 · 街机射击：敌人波次与碰撞 ​

1. 敌人 Group + 定时器 ​

2. overlap ≈ 引擎版 hit() ​

3. 出屏敌人也要回收 ​

4. gameOver 时停输入 ​

验收清单 ​

下一篇 ​

09 · 街机射击：敌人波次与碰撞

1. 敌人 Group + 定时器

2. overlap ≈ 引擎版 hit()

3. 出屏敌人也要回收

4. gameOver 时停输入

验收清单

下一篇