feat(bounce): bullet_manager 命中弹跳分支(优先于pierce)+跳过已访问+_find_nearest_unvisited 寻的

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/autoloads/bullet_manager.gd

@@ -73,6 +73,10 @@ func _check_collision(bullet_idx: int, base: int) -> bool:
 		var dist_sq: float = dx * dx + dy * dy
 		if dist_sq > query_r * query_r:
 			continue
+		if _bullet_contexts.has(bullet_idx):
+			var vt = _bullet_contexts[bullet_idx].get("visited_targets", null)
+			if vt != null and entity_id in vt:
+				continue   # 弹跳已命中过此敌：跳过，避免密集群内重复命中
 		# 命中：通过 DamageContextPool 发出伤害
 		var ctx_id: int = DamageContextPool.acquire(b_dmg, b_mult, b_type, b_own, false, 0.0)
 		EnemyManager.apply_damage_from_context(entity_id, ctx_id)
@@ -99,6 +103,25 @@ func _check_collision(bullet_idx: int, base: int) -> bool:
 		if payload_id >= 0:
 			var parent_depth: int = int(cold.get("trigger_parent_depth", 0))
 			SpellEvaluator.execute_sub(payload_id, hit_pos, b_own, parent_depth + 1)
+		# bounce 处理（优先于 pierce）：命中后弹向最近未访问敌人，伤害递减
+		var bounce: int = int(cold.get("bounce_remaining", 0))
+		if bounce > 0:
+			var visited: Array = cold.get("visited_targets", [])
+			visited.append(entity_id)
+			var next_id: int = _find_nearest_unvisited(Vector2(bx, by), float(cold.get("bounce_range", 250.0)), visited)
+			if next_id >= 0:
+				var np: Vector2 = EnemyManager.get_pos_by_id(next_id)
+				var spd: float = Vector2(_data[base + 2], _data[base + 3]).length()
+				var dir: Vector2 = (np - Vector2(bx, by)).normalized()
+				_data[base + 2] = dir.x * spd
+				_data[base + 3] = dir.y * spd
+				_data[base + 7] *= float(cold.get("bounce_decay", 0.9))
+				cold["bounce_remaining"] = bounce - 1
+				cold["visited_targets"]  = visited
+				_bullet_contexts[bullet_idx] = cold
+				return false
+			_swap_and_pop(bullet_idx)
+			return true
 		# pierce 处理
 		var pierce: int = int(cold.get("pierce_remaining", 0))
 		if pierce > 0:
@@ -174,6 +197,23 @@ func sync_multimesh(mm: MultiMesh) -> void:
 			0.0, Vector2(r * 2.0, r * 2.0), 0.0,
 			Vector2(_data[base + 0], _data[base + 1])))
 
+## 弹跳寻的：query_circle 半径内滤除已访问/哨兵，取最近 entity_id；无则 -1
+func _find_nearest_unvisited(origin: Vector2, radius: float, visited: Array) -> int:
+	var hits: PackedInt32Array = SpatialGrid.query_circle(origin, radius)
+	var best_id: int = -1
+	var best_sq: float = radius * radius
+	for eid in hits:
+		if eid in visited:
+			continue
+		var p: Vector2 = EnemyManager.get_pos_by_id(eid)
+		if p == Vector2(-9999.0, -9999.0):
+			continue
+		var d: float = origin.distance_squared_to(p)
+		if d <= best_sq:
+			best_sq = d
+			best_id = eid
+	return best_id
+
 func get_nearest_enemy_pos(origin: Vector2, max_dist: float = 9999.0) -> Vector2:
 	return EnemyManager.get_nearest_pos(origin, max_dist)