|index||The index of the tile to check for.|
With this function you can check wither the tile indexed exists
in the room or not. Please note that if you check for a tile by its
id and its id is uninitialised, an error will be thrown.
tile = tile_add(bck_Room1, 0, 0, 32, 32, mouse_x, mouse_y, -1100);
The above code checks to see if a tile that was indexed in the variable "tile" still exists in the room, and if it does not it creates a new tile at the mouse position and stores the new index in the variable "tile".