feat: 添加手枪武器

scenes/projectiles/projectile.gd

@@ -0,0 +1,23 @@
+extends Node2D
+class_name Projectile
+
+@export var hitbox: HitboxComponent
+
+var velocity: Vector2
+
+func _process(delta: float) -> void:
+	position += velocity * delta
+
+func set_projectile(velocity: Vector2, damage: float, critical: bool, knockback: float, unit: Node2D) -> void:
+	self.velocity = velocity
+	rotation = velocity.angle()
+	if hitbox:
+		hitbox.setup(damage, critical, knockback, unit)
+	
+
+func _on_visible_on_screen_notifier_2d_screen_exited() -> void:
+	queue_free()
+
+
+func _on_hitbox_component_on_hit_hurtbox(hurtbox: HurtboxComponent) -> void:
+	queue_free()