ai.gd

extends Node

export(flag) var behaviours;

const GO_TO_CHECKPOINT = 1;
const EVADE = 2;
const EVADE_WALLS = 4;
const PICKUP_PERK = 8;

const ADVANCE_STEP_DISTANCE = 8200.0;

export(float) var go_to_chkp_strenght

var next_checkpoint = 0 setget _recalculate_path;
var loop_count = 0;
var vehicle_node;

#Used for Go_to_checkpoint
var path;
var nav_helper;

#Used for Evade
var near_bodies = [];

#Used for Evade_walls
var raycasters = [];

func _ready():
	nav_helper = get_node("/root/Node/Navigation2D");
	vehicle_node = get_node("..");
	
	var rc = get_node("RayCast1");
	if (rc != null):
		rc.add_exception(vehicle_node);
		raycasters.append(rc);
	rc = get_node("RayCast2");
	if (rc != null):
		rc.add_exception(vehicle_node);
		raycasters.append(rc);
	rc = get_node("RayCast3");
	if (rc != null):
		rc.add_exception(vehicle_node);
		raycasters.append(rc);
	
	self.next_checkpoint = 1;
	

func game_start():
	set_fixed_process(true);

func _recalculate_path(val):
	next_checkpoint = val;
	path = nav_helper.get_path_to_checkpoint(vehicle_node.get_pos(), next_checkpoint);
	

func _fixed_process(delta):
	
	var force = calculate_force();
	
	if (force.y > 0.1):
		vehicle_node.movement_axis = -1.0;
	elif (force.y < -0.1):
		vehicle_node.movement_axis = 1.0;
	else:
		vehicle_node.movement_axis = 0.0;
	
	if (force.x > 0.1):
		vehicle_node.torque = 1.0;
	elif (force.x < -0.1):
		vehicle_node.torque = -1.0;
	else:
		vehicle_node.torque = 0.0;
	


func calculate_force():
	var force = Vector2();
	
	if (behaviours & GO_TO_CHECKPOINT):
		force += _go_to_checkpoint();
#		force = force.normalized();
	
	if (behaviours & EVADE):
		force += _evade();
#		force = force.normalized();

	if (behaviours & EVADE_WALLS):
		force += _evade_walls();
#		force = force.normalized();
	
	if (behaviours & PICKUP_PERK):
		force += _pickup_perk();
#		force = force.normalized();
	
	
	return force.normalized();
	

func _go_to_checkpoint():
	if (path == null || path.size() == 0):
		return Vector2();
	var step = Vector2();
	step = (path[0] - vehicle_node.get_pos())
	if step.length_squared() < ADVANCE_STEP_DISTANCE and path.size() > 1:
		path.remove(0);
	var m = Matrix32(-vehicle_node.get_rot(), Vector2());
	step = m * step;
	return step;

func _evade():
	return Vector2();
	

func _evade_walls():
	var rc = RayCast2D.new();
	var pos = Vector2();
	pos = vehicle_node.get_pos();
	var nearest_dist = 999999.0;
	var magnitude = 0.0;
	var direction = Vector2();
	for rc in raycasters:
		if rc.is_colliding():
			if (pos.distance_squared_to(rc.get_collision_point()) < nearest_dist):
				nearest_dist = pos.distance_squared_to(rc.get_collision_point());
				direction = rc.get_collision_normal();
				magnitude = rc.get_cast_to().length_squared() / nearest_dist;
	
	return direction * magnitude;
	

func _pickup_perk():
	return Vector2();