TAP/TGM edge case: rows 21 & 22

Thread in 'Research & Development' started by Xaphiosis, 4 Mar 2016.

  1. For my own amusement, I am coding up a training mode of sorts for TGM/TAP, and to test some silly ideas. However, in the game I am encountering edge cases not really talked about on the wiki. One of those is how pieces get into rows 21&22 of the playfield (overlapping, and even exceeding the playfield bounding box).

    I have been able to get J/L/T to do this, but also have a vague recollection of seeing an I piece go all the way up to 22. These are valid rows, since if you are fortunate enough to clear a line, they descend back into the 20-row playing field. It feels like the game tries to prevent you from rotating pieces into those rows, but do they wallkick into there or something? This is mostly on TAP, where playing death mode leads to regular ceiling exploration, but I'm assuming TGM has this too.

    Could someone point me to a thread or explanation for this mechanic? Looking at the wiki, it just says "play field size: 20", which it clearly is not.

    EDIT: Here is a valid example of row 21 being used in TAP Master. I can't seem to be able to replicate row 22 happening (did I dream it?):
    Last edited: 4 Mar 2016
  2. Xaphiosis likes this.
  3. DeHackEd

    DeHackEd green Gm

    There is no row 22 in TGM. If you do try to use row 22 (as said above, big mode can get a block into there) it will instead be cropped off. You can also test this in VS mode by building a tall pillar on the side and having the other player send lots of garbage.

    Row 21 is pretty easy since most pieces will have a row 21 presence when rotated from spawn orientation at spawn altitude.
    Xaphiosis likes this.
  4. That clears it up completely. Thanks!

    Why does the wiki say the playfield is 10x20 though? That's quite misleading.
  5. DeHackEd

    DeHackEd green Gm

    The frame going around the playfield is 10x20. Pieces spawn flush with the top of that frame. Row 21 is a quirk because the rotation system technically allows it.

    As I recall a number of TTC-spec games have way more than 21 or 22 rows. Some have around 40 rows total. (People tested this using the VS garbage method) Would you say the playfield is 40 rows tall?
  6. K


    this might help you :
    actually it's better if your "engine" does not display over row 20 or 21 because of disturbing visual artifact. But must keep track of those "hidden stacked block" in "memory" because it might give you an odd number of blocks in the playfield after skimming. Some integrist might not appreciate :D
  7. Zaphod77

    Zaphod77 Resident Misinformer

    sega tetris didn't even allow sticking above the field at all.

    tgm1 added the ability to stick ONE row above to allow rotation at the top Only one row was needed because no piece could ever stick above it without big mode. since the I did not kick.

    Big mode was a joke pretty much in the first game, and was totally unbalanced, allowing 8 line clears to be scored. So they didn't consider it a problem.

    When they rebalanced it in TGM2, they most likely decided to keep the cropping behavior on purpose, to increase the challenge. Only in big mode could you ever get a piece chopped off, in that game as well.

    With the new I floorkick in tgm3, it's possible to get one or two blocks of an I chopped off, and MAYBE possibly a T with extreme effort that I cannot figure out, but before that, it was physically impossible for a normal sized piece to get high enough for that to happen with ARS.

    SRS, as we all know, is a whole other ballgame, and needs at least three, and can handle many more in most implementations. 20 should be plenty for SRS, as more than 20 lines of garbage will cause a top out, and locking any piece fully above the field is a lock out.
    Xaphiosis likes this.
  8. That's fascinating! The difference between SRS-style where more rows are invisible but stored (K's animation, as seen on https://tetris.wiki/Playfield ) and the TGM style where they are chopped off early is what resulted in my misconception about the TGM playfield being a different size.

    The chopping behavior isn't very intuitive to me, so thank you for taking the time to explain this so patiently.

Share This Page