feat: Enhance game mechanics and structure

- Added `ColorBar` class for visual representation of values.
- Expanded `EntityBase` with new properties: `isBoss` and `weapons`, and implemented damage handling and entity generation methods.
- Updated `EntityStateBar` to use `ColorBar` for health representation.
- Introduced `BulletBase` scene and script for bullet mechanics, including damage handling and generation.
- Created `WorldTool` for managing the game world and root node.
- Implemented `EntityTool` for retrieving entities from hurtboxes.
- Added `GameRule` for managing game rules like friendly fire.
- Updated scene files to reflect new structures and added necessary resources.

scripts/Statemachine/BulletBase.gd

@@ -0,0 +1,33 @@
+extends Area2D
+class_name BulletBase
+
+@export var speed: float = 1
+@export var damage: float = 10
+
+var launcher: EntityBase = null
+
+func _ready():
+	area_entered.connect(hit)
+
+func hit(target: Node):
+	var entity: EntityBase = EntityTool.fromHurtbox(target)
+	if !entity || !launcher: return
+	if entity == launcher: return
+	if GameRule.allowFriendlyFire:
+		if entity.isPlayer() == launcher.isPlayer(): return
+	entity.takeDamage(self)
+
+static func generate(
+		bullet: PackedScene,
+	 	launchBy: EntityBase,
+	  	spawnPosition: Vector2,
+	  	spawnRotation: float,
+	   	addToWorld: bool = true
+	):
+	var instance: BulletBase = bullet.instantiate()
+	instance.launcher = launchBy
+	instance.position = spawnPosition
+	instance.rotation = spawnRotation
+	if addToWorld:
+		WorldTool.rootNode.add_child(instance)
+	return instance

scripts/Statemachine/ColorBar.gd

@@ -1,5 +1,6 @@
 @tool
 extends Control
+class_name ColorBar
 
 @export var minValue: float = 0
 @export var maxValue: float = 100

scripts/Statemachine/EntityBase.gd

@@ -3,6 +3,8 @@ class_name EntityBase # 这是个抽象类
 
 @export var maxHealth: float = 100
 @export var movementSpeed: float = 1
+@export var isBoss: bool = false
+@export var weapons: Array[Node2D] = []
 
 @onready var animatree: AnimationTree = $"%animatree"
 @onready var texture: AnimatedSprite2D = $"%texture"
@@ -28,9 +30,32 @@ func move(direction: Vector2):
 	var currentDirection = sign(direction.x)
 	if currentDirection != 0:
 		lastDirection = currentDirection
+func takeDamage(bullet: BulletBase):
+	health -= bullet.damage
+	if health <= 0:
+		die()
+
+# 关于分组
+func isPlayer():
+	return is_in_group("players")
 
 # 抽象方法
 func ai():
 	pass
 func attack(_type: int):
 	pass
+func die():
+	queue_free()
+
+static func generate(
+	entity: PackedScene,
+	spawnPosition: Vector2,
+	spawnRotation: float,
+	addtoWorld: bool = true
+):
+	var instance = entity.instance()
+	instance.position = spawnPosition
+	instance.rotation = spawnRotation
+	if addtoWorld:
+		WorldTool.rootNode.add_child(instance)
+	return instance

scripts/Statemachine/EntityStateBar.gd

@@ -2,7 +2,7 @@ extends Node2D
 
 @export var entity: EntityBase
 
-@onready var healthBar = $"%health"
+@onready var healthBar: ColorBar = $"%health"
 
 func _process(_delta):
 	if entity:

scripts/Tools/EntityTool.gd

@@ -0,0 +1,10 @@
+class_name EntityTool
+
+static func fromHurtbox(node: Node) -> EntityBase:
+	if node is Area2D:
+		var texture = node.get_parent()
+		if texture is AnimatedSprite2D:
+			var entity = texture.get_parent()
+			if entity is EntityBase:
+				return entity as EntityBase
+	return null

scripts/Tools/GameRule.gd

@@ -0,0 +1,3 @@
+class_name GameRule
+
+static var allowFriendlyFire: bool = false # 是否允许友军伤害

scripts/Tools/WorldTool.gd

@@ -0,0 +1,9 @@
+extends Node2D
+class_name WorldTool
+
+static var rootNode: Node2D
+static var tree: SceneTree
+
+func _ready():
+    tree = get_tree()
+    rootNode = self