Entry 309

Back in town: the members' kit and the trade lists restocked, their faces

2026-09-30worldsaveui

Filescrates/piney-battle/src/restock.rscrates/piney-battle/src/lib.rscrates/piney-world/src/area.rscrates/piney-game/src/session.rscrates/piney-game/src/session/tests/town_return.rsBUGS.md

Three player reports (GitHub issues 3, 4 and 9), all about coming back to a Root Town from a field in Infection.

The rule: two steps of ccSetupGameCtrl

INF main 0x00168ca0-0x00168f74, after ccStartThEvent and before the file lists, branches on ccGame.area (+0x14) and whether the scene is new (area, town, field, dungeon against their previous values, the port's Scene::changed):

Nothing when the scene is the same (a dungeon's next floor, an event's scene -2). Mutation (0x00168ae0), Outbreak (0x00167d90) and Quarantine branch the same way.

ccSaveData::SetSpcItemTown (INF main 0x00176260): for members 1-17 (1-20 from Mutation on) whose bits are set in both partyMemberFlag (+0x2220) and partyMemberCall (+0x2224). Past 20 stacks, the member sells, as many times as he has stacks over 20, the cheapest stack he may (ccGetItemPrice, the last of equal prices; never category 10 rows 0-5 and 18-23, 13/1, or member 1's 14/10): num * price / 2 into his own spcParam.base.gold (+0x14), capped at 9,999,999, and DelItem of the stack. Then each of his ten spcDefaultItemList rows (gcmn 0x00647d80) tops up to its count by AddItem, (count - held) * price off his gold, held at 0. Kite's gold is never touched: the reporter's "no GP" is Kite's.

SetTradeItemTown (INF main 0x001767a0): the members' lists (save +0xe3c, 16 slots) and the NPCs' (+0x127c, 48 lists, first 15 slots) get back each spcDefTradeList / npcDefTradeList row whose sw word (the row's bytes 4-7, the reporter's "4th byte") is set. Every member's first row in Infection is the Speed Charm (11/56) with sw 1. Then each NPC, if rand() & 1, draws a category rand() % 10 and offers in its 16th slot a piece near Kite's: his weapon (+0xd0) looked up in feTbl[0], or his armour piece (+0xc8 + 2k) in feTbl[6 + k], among the first f_limitTbl[10 + server] rows ([15 + server] for category 2), moved by rand() % 4 - 1, held to 0..limit, feTbl[category]'s row there, count 1, unless the first 15 slots have it. Mutation, Outbreak and Quarantine: the same code over 20 member lists and 54 NPC lists (the last 3 and 6 in the save's extension); only the member count and the table addresses differ in the listings.

What the port did

Neither step existed: a traded Speed Charm stayed gone (issue 9, NPCs too) and a member's used-up potions never came back (issue 4).

The fix

piney_battle::restock: item_price, set_spc_item_town, set_trade_item_town over the save and the volume's tables (no new table: spc_default_items, spc_trade, npc_trade, fe_tbl, f_limit were all in the build). Scene::restock (piney-world) decides the steps as above; the session applies them to the save before building each scene's mode, and at Log in. newlib's rand() is a session-held Rand (the modes keep their own, so their sequences are as before).

Checked against the game: a scratch harness ran InitTradeItem, then SetSpcItemTown and SetTradeItemTown natively in eemu on eight made-up saves (every address known, lists of 0-40 random stacks, gold up to near the cap, Kite's pieces from the feTbl lists, 40 trades taken, servers 0 and 1, rand from a seeded generator), and the Rust over the same saves and draws: byte-exact on all eight, the draw count too. Items past a table's rows were left out: the game reads past the table there (category 13 rows 3-7 price -1), the port prices them 0.

Issue 3: the faces

Already fixed by WorldMode::set_spcs (the BlackRose face fix in BUGS.md, committed 2026-09-28, the day the repository went up): before it the town set only Kite's menu face, so a member's face was empty on the status page and panels after any way back from a field, which is the report. Every return (a Gate Out, the Sprite Ocarina, an event's scene, the console's town) goes through Session::enter_world, which calls it; the Party menu's own add (PartyInMenu step 31) sets the face in town. The game's rule for the record: ccCheckMenuFaceNameParty (gcmn 0x0056a930) is called only by ccMenuCtrl's constructor (gcmn 0x0051c7fc), once per scene, for slots 0-2 from ccPartyManager.memberID; SetMenuFace (0x00526940) only by the event's party_add.

Tests

session/tests/town_return.rs, each failing with the step (or the face loop) switched off: faces_come_back_from_a_field (Orca called by the Party menu, to a field and back), the_kit_comes_back_in_town (Orca's kit used up, his gold 5000; back in Mac Anu the kit is whole and the cost off his gold, Kite's as it was), trades_come_back_each_scene (Orca's Speed Charm and an NPC's trade taken; back in both in Mac Anu and again in the field after). restock.rs's own: the sale past 20, an unknown member left alone, an NPC's restock and pick, every volume's kit. area.rs: restocks_by_the_scene_left.