Godot Version 4.2.2

Guys, I’m a noob as freshly printed money and with the help of the internet gods I managed to get to the point you see in the image.

I’m using Tilemap because of its Grid capabilities.
I used a script with the draw function just to draw lines where the grid is displayed.

My intention is to get the final result of image 2. My problem is that the grid and the tiles are “painted” by script. See below:

My scene (node2d) has 2 child nodes:

• GridDraw(Node2D) just to draw the grid lines
• TileMap (with the tiles/terrains settings) that contains the tiles.

I’ve used Jackie Codes – Godot 4 Tilemap Tutorials playlist to achieve this result:
https://youtu.be/G6TC6ukmSc4?si=V32bqBV-R-TYvO_2

My setup:

Viewport portrait: 576 x 1024

Tiles and grid cell: 64px

My scripts:

grid_draw.gd

extends Node2D

var viewport_size: Vector2;

func _ready() → void:
viewport_size = get_viewport().get_size();

func _draw():

var cell_size = 64;
var offset = cell_size / 2;

    # Draw horizontal lines
    for y in range(offset * (-1), viewport_size.y, cell_size):  
        draw_line(Vector2(0, y), Vector2(viewport_size.x, y), Color.KHAKI);

    for y in range(0, viewport_size.y, cell_size):  
        draw_line(Vector2(0, y), Vector2(viewport_size.x, y), Color.INDIAN_RED);

# Draw vertical lines
    for x in range(offset * (-1), viewport_size.x, cell_size):
        draw_line(Vector2(x, 0), Vector2(x, viewport_size.y), Color.KHAKI)

    for x in range(0, viewport_size.x, cell_size):
        draw_line(Vector2(x, 0), Vector2(x, viewport_size.y), Color.INDIAN_RED)

tilemap_grid.gd

extends Node2D;
   
const LAYER = 1; # ground
var tile_source_id = 0; # id of the tile set atlas
var atlas_coords = Vector2i(0,7); # tile to place
var terrain_set_id = 0;
var terrain_id = 0;
var viewport_size: Vector2;
enum Tilesets {
    Terrains, Objects
}
    
@onready var tile_map: TileMap = $TileMap;
    
func _ready() → void:

    viewport_size = get_viewport().get_size();

# Fill water
    fill_area_with_tile(
        tile_map.local_to_map(Vector2(0,0)),
        tile_map.local_to_map(Vector2(viewport_size.x,viewport_size.y)),
        Tilesets.Terrains,
        Vector2i(0,12)
    );

#Fill Base Island
    fill_area_with_terrain_connected(
        Vector2i(1,6),
        Vector2i(8,13),
        LAYER,
        terrain_set_id,
        terrain_id
    );

func fill_area_with_tile(start: Vector2i, end: Vector2i, tileset_id: int, tile_coords: Vector2i, layer: int = 0) → void:
    for x in range(start.x, end.x):
    for y in range(start.y, end.y):
    tile_map.set_cell(layer, Vector2i(x,y), tileset_id, tile_coords );

func fill_area_with_terrain_connected(start: Vector2i, end: Vector2i, layer: int, terrain_set_id: int, terrain_id: int) → void:
    for x in range(start.x, end.x):
    for y in range(start.y, end.y):
    tile_map.set_cells_terrain_connect(layer, [Vector2i(x,y)], terrain_set_id, terrain_id)