Live on rung 9 thirty-five minutes after v0.4.2: NEXT 1264 macro starts, BACK
1241, the log alternating NEXT start/done, BACK start/done every hold, on map
51. NEXT on the top-level battle menu is an A press on the cursor, and the
cursor sits on FIGHT, so it opened the move list; BACK on the move list closed
it again. Each button was legitimate where it stood, and the pair undid itself
with nothing else changing, so the turn never resolved.
NEXT is now on no pad with a cursor accepting input. It keeps the between-turns
row alone and the forced switch, which has no BACK beside it to undo it. MOVE 1
is the top-level menu's backstop instead: the question over that menu is 12.8's
"is there a move list to open", FIGHT always opens, and the script there is
confirm FIGHT and stop, which reads no move at all.
The bag is the fly's own turn, because a cursor accepting input is one, and its
pad is the bag's own three answers: ITEM, THROW BALL, BACK. Section 12.10.
The buffer is ds 1300 and every real map plus its three-block border fits in it.
A header that says otherwise is one read mid-load, and decoding it would read
past the buffer into somebody else s WRAM, so it is a refusal rather than a
clamp.
A warp writes wCurMap before the map header and the block data: on Oak s lab
doormat wCurMap already reads PALLET_TOWN while the header still reads the lab s
ten-by-twelve. The decode agrees with the screen on such a frame -- both are the
old map -- so only the id is wrong, and a grid filed under it would stay wrong
for as long as it was cached. One byte answers it: does the cached grid still
agree with the screen about the tile the fly is standing on.
The walkable predicate answered for the ten-by-nine screen window and Unknown
everywhere else. MapGrid is the same rule over every tile of the loaded map:
block ids out of wOverworldMap, a blocks-to-tiles read of the tileset header s
blockset through the new bank-aware ROM read, the tileset s collision list as
before, and the TilePairCollisionsLand values as directed walls both ways.
The reader checks itself before it answers: the decode is compared against the
window predicate over the player s own neighbourhood, and a frame where the
window can answer for none of it -- a battle, a text box, a frame mid-warp -- is
refused, because wOverworldMap shares its bytes with the picture buffer. Every
refusal is named (GridRefusal) and leaves the window predicate in charge.
Cached per map id and size, so a map is decoded once on arrival rather than once
per question, and owned beside the session ledgers: never checkpointed.