godot-steering-ai-framework/project/demos/FollowPath/PathFollower.gd

extends KinematicBody2D


var _velocity := Vector2.ZERO
var _accel := GSAITargetAcceleration.new()
var _valid := false
var _drag := 0.1


onready var agent := GSAIKinematicBody2DAgent.new(self)
onready var path := GSAIPath.new([
		Vector3(global_position.x, global_position.y, 0),
		Vector3(global_position.x, global_position.y, 0)
	], true)
onready var follow := GSAIFollowPath.new(agent, path, 0, 0)


func setup(
			path_offset: float,
			predict_time: float,
			accel_max: float,
			speed_max: float,
			decel_radius: float,
			arrival_tolerance: float
	) -> void:
	owner.drawer.connect("path_established", self, "_on_Drawer_path_established")
	follow.path_offset = path_offset
	follow.prediction_time = predict_time
	follow.deceleration_radius = decel_radius
	follow.arrival_tolerance = arrival_tolerance
	
	agent.linear_acceleration_max = accel_max
	agent.linear_speed_max = speed_max
	agent.linear_drag_percentage = _drag


func _physics_process(delta: float) -> void:
	if _valid:
		follow.calculate_steering(_accel)
		agent._apply_steering(_accel, delta)


func _on_Drawer_path_established(points: Array) -> void:
	var positions := PoolVector3Array()
	for p in points:
		positions.append(Vector3(p.x, p.y, 0))
	path.create_path(positions)
	_valid = true