extends Node3D

@export var target: MeshInstance3D
@export var markdown: TextureRect
@export var markleft: TextureRect
@export var markright: TextureRect
@export var message: Label


func _ready():
	pass


func _process(delta):
	var cam = get_viewport().get_camera_3d()
	if cam == null:
		printerr("Not found Camera3D")
		return

	var cam_ang = Input.get_axis("ui_left", "ui_right") * (120.0 * delta)
	cam.rotate_y(deg_to_rad(cam_ang))
	
	var is_behind = cam.is_position_behind(target.global_position)
	var in_frustum = cam.is_position_in_frustum(target.global_position)
	
	var msg = ""
	msg += "behind: %s" % ("true" if is_behind else "false")
	msg += "\nin frustum: %s" % ("true" if in_frustum else "false")
	message.text = msg

	var viewport_size = get_viewport().get_visible_rect().size
	var screen_pos = cam.unproject_position(target.global_position)

	var tw = markdown.texture.get_width() / 2
	if not is_behind and (screen_pos.x > tw and screen_pos.x < (viewport_size.x - tw)):
		markleft.hide()
		markright.hide()
		markdown.show()
		markdown.global_position.x = screen_pos.x - tw
		#markicon.global_position.y = screen_pos.y - (markicon.texture.get_height())
	else:
		var camvec: Vector3 = -cam.global_transform.basis.z
		var tgtvec: Vector3 = (target.global_position - cam.global_position)
		var d = Vector2(camvec.x, camvec.z).cross(Vector2(tgtvec.x, tgtvec.z))
		if d > 0:
			markleft.hide()
			markright.show()
		elif d < 0:
			markleft.show()
			markright.hide()
		else:
			markleft.hide()
			markright.hide()
			
		markdown.hide()