const mag = Math.hypot(world.input.x, world.input.y);
p.moving = mag > 0.01;
const speed = p.baseSpeed * p.speedMult * Math.min(1, mag);
if (p.moving) {
    const nx = world.input.x / (mag || 1);
    const ny = world.input.y / (mag || 1);
    p.vel.x = nx * speed;

let dx = e.clientX - this.origin.x;
let dy = e.clientY - this.origin.y;

let dx = e.clientX - this.origin.x;
let dy = e.clientY - this.origin.y;
const dist = Math.hypot(dx, dy);
if (dist > TRAVEL) {
  dx = (dx / dist) * TRAVEL;
  dy = (dy / dist) * TRAVEL;
}
this.knob = { x: dx, y: dy };
if (dist < DEAD_ZONE) {
  this.vector = { x: 0, y: 0 };
} else {
  const mag = Math.min(1, (dist - DEAD_ZONE) / (TRAVEL - DEAD_ZONE));
  this.vector = { x: (dx / dist) * mag, y: (dy / dist) * mag };
}

const iv = this.inputProvider();
w.input.x = iv.x;
w.input.y = iv.y;

const mag = Math.hypot(world.input.x, world.input.y);
p.moving = mag > 0.01;
const speed = p.baseSpeed * p.speedMult * Math.min(1, mag);
if (p.moving) {
  const nx = world.input.x / (mag || 1);
  const ny = world.input.y / (mag || 1);
  p.vel.x = nx * speed;
  p.vel.y = ny * speed;

const iv = this.inputProvider();
w.input.x = iv.x; w.input.y = iv.y;

const dist = Math.hypot(dx, dy);
this.knob = { x: clamped dx, y: clamped dy }; // visuals
if (dist < DEAD_ZONE) vector = 0;
else {
  const mag = Math.min(1, (dist - DEAD_ZONE) / (TRAVEL - DEAD_ZONE));
  this.vector = { x: (dx / dist) * mag, y: (dy / dist) * mag }; // dx,dy ORIGINAL (unclamped)
}

case 'chest': {
  getAudio().playSfx('chest');
  const choice = engine.generateChestChoice();
  if (choice) {
    engine.setTimeScale(LEVELUP_TIMESCALE, LEVELUP_SLOWMO_RAMP_MS);
    slowmoTimer.current = setTimeout(() => engine.pause(), 200);
    s.openLevelUp([choice]);
  } else {
    s.setBanner('✦ 宝箱开启 ✦', 'minute');
  }
  break;
}

/**
 * 宝箱奖励(game.md §8):随机已有武器/被动直升 1 级,小概率给未拥有的异域武器;
 * 全满级兜底金币。返回 null 表示无法生成(理论上兜底金币保证非 null)。
 */
export function generateChestChoice(world: GameWorld): UpgradeChoice {
  const inv = world.inventory;
  const pool: PoolEntry[] = [];

  // 已有武器升级(权重 5)
  for (const slot of inv.weapons) { ... same as section 3 but weight 5 }
  // 已有被动升级(权重 4)
  for (const slot of inv.passives) { ... same shape as section 5 }
  // 异域武器(未拥有,权重 1.5,无时间门——宝箱是异域来源之一)
  const ownedW = new Set(inv.weapons.map(w => w.id));
  if (inv.weapons.length < MAX_WEAPON_SLOTS) {
    for (const def of EXOTIC_WEAPONS) if (!ownedW.has(def.id)) pool.push({weight: 1.5, make: () => newWeaponChoice(def)});
  }
  if (pool.length === 0) return { goldBonus 50 card };
  // weighted pick one
}

  generateChoices(): UpgradeChoice[] {
    return generateUpgradeChoices(this.world);
  }

case 'chest': {
  getAudio().playSfx('chest');
  const chestChoice = engine.generateChestChoice();
  engine.setTimeScale(LEVELUP_TIMESCALE, LEVELUP_SLOWMO_RAMP_MS);
  slowmoTimer.current = setTimeout(() => engine.pause(), 200);
  s.openLevelUp([chestChoice]);
  break;
}

case 'levelup':
  engine.setTimeScale(...);
  getAudio().playSfx('levelup');
  slowmoTimer.current = setTimeout(() => engine.pause(), 200);
  s.openLevelUp(e.choices);
  break;

p.active = true; p.type = 'chest'; ...   // planted!
await new Promise(...1200ms);
const store = (await import(...))        // threw AFTER planting

if (w.chestOpened) {
  if (w.pendingLevelUps > 0) {
    // 让位于升级弹窗,下一帧再发
  } else {
    w.chestOpened = false; fire chest
  }
}

const hasLevelUp = w.pendingLevelUps > 0 && !w.gameoverFired;
if (hasLevelUp) { w.pendingLevelUps = 0; fire levelup }
...
if (w.chestOpened && !hasLevelUp) { w.chestOpened = false; fire chest }