Entry 64

The field UI: ccThMenu's HUD, event windows and battle menus, frame by frame against the game

2026-09-23uitest

Filescrates/piney-fielduicrates/piney-desktop/src/message.rscrates/piney-desktop/src/save.rstools/test_fieldui_rs.pydocs/engine/field-ui.md

To play the opening arc, the field needs its user interface: the party panels and target window, the event scripts' message windows, and the menus a battle runs on. All of it is one task in GCMN.PRG's menu.cpp, ccThMenu (0x005280d0, priority 34), driving ccMenuCtrl. A helper agent ported it as the new crate piney-fieldui; the design is in docs/engine/field-ui.md.

What it is

• The task. FieldUi::step(pad, world, save, count) is one pass between two Breath calls:

  • the menu asked for (openReqNum);
  • the change between menus (menuNext);
  • the open menu's handler from the jump table at 0x006e0300;
  • Disp.

• The HUD (Disp, 0x0051cfb0):

  • the party panels, with HP and SP bars in ccGetNowMaxColor's colours;
  • the target cursor and window;
  • the enemies' life bars and off-screen arrows;
  • the protect-break marks and the battle banner;
  • the bracelet's gauge, the dim and the minimap's alpha;
  • the new-mail notice.

  Every sprite packet is sent in the game's order.

• The event windows (ccMessage): speech, information and tutorial windows, and ccEvent::DispInfo's announcements. They are reached through the seam the event engine's field host will call: message_open, message_check, message_close, announce, menu_ban, open_menu, target_forbid, map_on and noise.

• The menus ported:

  • PERSONAL (0-2) and OPTION (12);
  • CHAT (3);
  • Skills (4), with revival and Data Drain's sub-target;
  • Items (5), including the special items;
  • TARGET (65);
  • the party tutorial's first two (75, 76).

  Any other number closes at once with Request::Unported(n). The table of all 89 numbers is in the doc.

• The world, read-only. A World the runtime fills each frame: the game's area and battle state, the three party slots, cmndTarget and cmndTargetPrev, cmndSortRoot's chain with screen points, the three cmndLink chains, and the player's flags.

• Requests. What the menus do to the rest of the game comes back as Requests, in order:

  • sounds and voices;
  • putting the other tasks to sleep and waking them, with the frozen layers;
  • target changes;
  • skill and item uses, and Data Drain's hold and SP;
  • chat orders and the chat line;
  • the minimap's alpha.

Also changed

• piney-desktop.
  • MsgWindow gained the field's helpers.
  • SaveState::fresh now writes all eleven button assignments from +0x8404, as ccSaveData::Init does: action, personal menu, chat, option, map, ok, cancel, and the camera's four. Before, it wrote only ok and cancel.
• demo_probe.rs. Reformatted by cargo fmt after 63's fix.

Checked

• Against the game. tools/test_fieldui_rs.py (20 tests) runs the game's ccThMenu from its start in eemu, with its leaf calls hooked, and the same scenario through fieldui_probe. Every frame it compares:

  • the menu's and message window's state;
  • every sprite packet;
  • the kanji rows;
  • sounds, voices and target changes;
  • skill and item requests and chat orders;
  • the save's item list.

  The scenarios cover:

  • the panels and the windows;
  • the fallen player;
  • five kinds of target;
  • the enemy bars, the banner, new mail and low HP;
  • every Skills page, revival and Data Drain, and the refusals;
  • Items, including the special items;
  • CHAT in a field, a dungeon, a town and alone;
  • ten random pad runs through the battle menus.

  All pass.

• Nothing else broke. In a clean worktree, the desktop's four suites, test_demo_rs and test_toppage_rs pass on top of the change.

• The workspace. Its tests pass; clippy, including piney-fieldui with trace, and fmt are clean.