tripatch - Triptych Patch Installer & Toolkit

A single small .exe that installs (and authors) translation patches for Triptych (ALcot, 2014 Download Edition, AZSys engine).

There are two ways to use it:

• Players just double-click tripatch.exe and follow two dialogs.
• Translators use the extract and build commands from a terminal.

---

For players: installing a patch

1. Put tripatch.exe and the patch file (a .json) anywhere you like.
2. Double-click tripatch.exe.
3. A window opens and asks you to pick the patch .json file.
4. Then it asks you to pick the game folder - the folder that contains triptych.exe and script.arc.
5. It checks that the folder really is the game, applies the patch, and shows a success message. Press Enter to close.

That's it. You can re-run it as many times as you want.

How it protects your game

The first time you patch, the installer copies the original script.arc into a backup\ folder inside the game directory:

<game>\script.arc            <- the file the game loads (gets patched)
<game>\backup\script.arc     <- pristine original, created automatically

On every run it patches from the backup, never from the already-patched file, so re-installing or switching patches never stacks corruption. Your original is always safe.

Uninstalling

Copy backup\script.arc back over script.arc. Done.

---

For translators: authoring a patch

The tool exposes two commands. Both take --input / --output paths.

1. Extract the text

tripatch extract --input path\to\script.arc --output texts.json

• Reads the original script.arc.
• Makes a pristine backup next to it (backup\script.arc) and reads from that.
• Writes every translatable line to texts.json.

2. Translate

Open texts.json in any UTF-8 text editor and fill in the "en" fields:

{
  "_meta": { "source": "script.arc", "...": "..." },
  "files": {
    "kar_c1_000_01.asb": [
      { "offset": "0x18f", "type": "text",
        "jp": "太陽が水平線の向こうに沈んでいく。",
        "en": "The sun sinks beyond the horizon." },
      { "offset": "0xc341", "type": "choice",
        "jp": ["選択肢A", "選択肢B"],
        "en": ["Option A", "Option B"] }
    ]
  }
}

• An empty "en" keeps the original Japanese line.
• choice units use a list, one entry per option.
• Translations can be any length - records are resized and internal jump offsets are relocated automatically.
• offset is a stable anchor into the original script. Never edit it.

3. Build / apply

tripatch build --input texts.json --output path\to\game-folder --verify

• --output is the game folder (or the script.arc path directly).
• Creates backup\script.arc if missing, patches from the backup, writes the result over the game's script.arc.
• --verify decrypts and re-parses every script in the result as a self check.

The finished texts.json is the patch you ship to players - they just double-click tripatch.exe and select it.

---

How it works (technical)

script.arc is an AZSys ARC\x1a container holding 347 encrypted .asb scripts. Each script is zlib-compressed and additively encrypted (game key 0x1DE71CB9) and contains bytecode records:

+0  u32  opcode
+4  u32  record length (including this 8-byte header)
+8  ...  args

Text lives inline (CP932, NUL-terminated) in these opcodes:

opcode	meaning	extracted as
0x04	scene title	title
0x29	speaker name	speaker
0x2a	dialogue	text
0x0d	choice menu	choice (list of options)

Opcodes 0x0a, 0x0b, 0x0c are jumps whose first argument is an absolute byte offset into the same script; when a record is resized, every jump target is relocated. The ARC index is LZSS-compressed with a CRC32 and is rebuilt and re-signed, so entries can grow freely.

Building from source

Requires a Rust toolchain (cargo):

cargo build --release

The binary is written to target\release\tripatch.exe.

---

Notes & caveats

• Output encoding is CP932 (ASCII is a subset, so plain English is safe). Smart quotes, en/em dashes and ellipses are auto-converted to CP932-safe forms; any other unmappable character aborts the build with a clear message.
• The engine wraps long Japanese text and may break long English lines mid-word; keep lines short if that bothers you.
• Saves made mid-scene with the old script.arc store a script position and may resume at the wrong spot after patching. Save at choice or title screens, or start a fresh game when in doubt.
• UI text (menus, config) is not in script.arc; it lives in system.arc and the executable, and is not handled here.