Build with and for GMS2. This scripts help you auto-tile directly in game. Perfect for procedurally generated levels. It uses a tileset of 47 images placed in the same order as in the IDE of GMS2. It auto-tiles on a ds_grid but it can be easily changed for arrays. Note that GMS is still in beta and asset will be updated if bugs occur.
Bonus: To help you create images: Tile47Jo
Small fix in the switch statement of scr_autotile