Basic random walker script

basic_walker.gd

extends Node2D

onready var dirt_tilemap = $DirtTileMap
onready var wall_tilemap = $WallTileMap

var rng = RandomNumberGenerator.new()

var CellSize = Vector2(16, 16)
var width = 1024/CellSize.x
var height = 1024/CellSize.y
var grid = []

var Tiles = {
    "empty": -1,
    "wall": 0,
    "floor": 1
}

func _init_grid():
    grid = []
    for x in width:
        grid.append([])
        for y in height:
            grid[x].append(-1);

func GetRandomDirection():
    var directions = [[-1, 0], [1, 0], [0, 1], [0, -1]]
    var direction = directions[rng.randi()%4]
    return Vector2(direction[0], direction[1])
    
func _create_random_path():
    var max_iterations = 1000
    var itr = 0
    
    var walker = Vector2.ZERO
    
    while itr < max_iterations:
        
        # Perform random walk
        # 1- choose random direction
        # 2- check that direction is in bounds
        # 3- move in that direction
        var random_direction = GetRandomDirection()
        
        if (walker.x + random_direction.x >= 0 and 
            walker.x + random_direction.x < width and
            walker.y + random_direction.y >= 0 and
            walker.y + random_direction.y < height):
                
                walker += random_direction
                grid[walker.x][walker.y] = Tiles.floor
                itr += 1
    
func _spawn_tiles():
    
    for x in width:
        for y in height:
  
            match grid[x][y]:
                Tiles.empty:
                    pass
                Tiles.floor:
                    dirt_tilemap.set_cellv(Vector2(x, y), 0)
                Tiles.wall:
                    pass

func _clear_tilemaps():
    for x in width:
        for y in height:
            dirt_tilemap.clear()
            wall_tilemap.clear()
  
    dirt_tilemap.update_bitmask_region()
    wall_tilemap.update_bitmask_region()

func _ready():
    rng.randomize()
    _init_grid()
    _clear_tilemaps()
    _create_random_path()
    _spawn_tiles()

Didn't work for me update_bitmask_region(). This worked when I moved to line 65 in the functions _spawn_tiles()