Stitching a terrain edge or corner from many small tile pieces, chosen by which neighbours
are the same terrain, rather than a game picking a frame per cell by hand.
A diagonal neighbour only changes a cell's shape when both orthogonal neighbours flanking
it also belong to the terrain - a corner piece already covers every case where one of them
does not, since the edge piece on that side owns the corner instead. That rule is what
collapses the 256 raw 8-neighbour combinations down to the 47 that are ever actually
reachable, and it is the whole of what "blob" autotiling is - not 256 hand-drawn tiles, 47.
blobIndex and BLOB_SHAPES are this module's own convention, not a claim of pixel
compatibility with any particular existing tileset's frame order - a tileset drawn for a
different engine's autotile layout will need its frames reordered into this one. What is
guaranteed: BLOB_SHAPES lists all 47 shapes in the exact order blobIndex returns them
in, so a tool (or a person, reading it once) can draw or arrange frames against it directly.
Stitching a terrain edge or corner from many small tile pieces, chosen by which neighbours are the same terrain, rather than a game picking a frame per cell by hand.
A diagonal neighbour only changes a cell's shape when both orthogonal neighbours flanking it also belong to the terrain - a corner piece already covers every case where one of them does not, since the edge piece on that side owns the corner instead. That rule is what collapses the 256 raw 8-neighbour combinations down to the 47 that are ever actually reachable, and it is the whole of what "blob" autotiling is - not 256 hand-drawn tiles, 47.
blobIndexandBLOB_SHAPESare this module's own convention, not a claim of pixel compatibility with any particular existing tileset's frame order - a tileset drawn for a different engine's autotile layout will need its frames reordered into this one. What is guaranteed:BLOB_SHAPESlists all 47 shapes in the exact orderblobIndexreturns them in, so a tool (or a person, reading it once) can draw or arrange frames against it directly.