Godot GDScript - An implementation of A* path finding algorithm for tilemap

ground.gd

extends TileMap

const WALKABLE = 2
var cells = Vector2Array()

func _ready():
	cells = get_used_cells()
	pass

func find_path(map_from, map_to):
	var list = []
	list.append({'g': 0, 'f': 0, 'pt': map_from, 'parent': -1})
	while (list.size()):

		var idx = _smallest_f(list)
		var c = list[idx]
		list.remove(idx)

		if (c.pt == map_to):
			var path = []
			while c.parent != -1:
				c = c.parent
				path.append(map_to_world(c.pt))
			return path

		for y in [-1, 0, 1]:
			for x in [-1, 0, 1]:
				if x == 0 && y == 0:
					continue

				var pos = c.pt + Vector2(x, y)
				var h = abs(pos.x - map_to.x) + abs(pos.y - map_to.y)
				var nb = {'g': c.g + 1, 'f': h + c.g + 1, 'pt': pos, 'parent': c}
				
				var idx = _search_in_list(pos, list)
				if idx && list[idx].g > nb.g:
					list[idx] = nb

				if WALKABLE == _search_in_cells(pos):
					list.append(nb)
	return []

func _search_in_list(pt, list):
	for i in range(list.size()):
		if list[i].pt == pt:
			return i
	return false

func _search_in_cells(p):
	for i in cells:
		if i == p:
			return get_cell(p.x, p.y)

func _smallest_f(list):
	var idx = 0
	for i in range(list.size()):
		if list[i].f < list[idx].f:
			idx = i
	return idx

func is_walkable(world_pos):
	var map_pos = world_to_map(world_pos)
	return get_cell(map_pos.x, map_pos.y) == WALKABLE