TILESET caveexpress-tileset-rock.tsx

RULE
    INPUT ground
    OUTPUT ground
    (0,0) = 2  # Dirt tile
    (1,0) = 1  # Grass tile (right)
    (-1,0) = 1 # Grass tile (left)
    (0,-1) = 1 # Grass tile (above)
    (0,1) = 1  # Grass tile (below)
    (0,0) -> 6 # Apply dirt-to-grass transition tile
END
