# File formats

All addresses are absolute VAs in `TheIOfTheDragon.exe` (image base `0x400000`).

## 1. `Data\Misc\Strings.dat` — plain text

Same syntax as the other `.dat` files, but **not** obfuscated. Blocks look like:

```
String
{
	Id = "WindowCaption"
	English = "..."
	Russian = "..."
	German  = "..."
}
```

- 499 blocks in the Steam build. Keys are `String{ Id, English, Russian, German }`
  (retail multilanguage builds also carry `Polish`, `Czech`, `Hungarian`, `Hungarian/Russian` variants
  split across separate installed files).
- **Translate only the language values.** Never touch `Id`.
- The file is single-byte code page text (Russian is CP1251).

## 2. `Data\Misc\Fonts.dat`, `UnitDescription.dat`, `AIDescription.dat` — XOR-obfuscated text

Layout: `b"==" + XOR(plaintext, repeating key)`.

- Magic `==` at VA `0x620D24`.
- Repeating XOR key `GBDFYTNE` (8 bytes) at VA `0x620D18`.
- Decoder/encoder routine at `0x4AE1D0`.

Decoded, these are the same text format as `Strings.dat`:

- `Fonts.dat`: `Font { Name; Language; Texture; SpaceWidth; LineDistance; Char { Code; X1;Y1;X2;Y2 } ... }`
- `UnitDescription.dat`: unit/enemy definitions (Russian comments in CP1251 + English keys).
- `AIDescription.dat`: `Brain { AI = ...; TypeAI = ...; ... }`.

Round-trip is exact; see `tools/decode_dat.py`.

## 3. `res` archives (`Textures.res`, `Geometry.res`)

```
uint32  count
repeat count:
    uint32  nameLen
    char[]  name            (backslash separated)
    uint32  offset          (absolute file offset)
    uint32  size            (exact blob size)
pad the index to 16 bytes
data region:
    for each entry: write blob, then pad to 16-byte boundary
    (the last blob is NOT padded)
```

- All offsets are 16-byte aligned.
- `Textures.res` holds 1884 entries: 947 TGA + 935 DDS (DXT1/DXT5) + 2 misc.
- `res_unpack.py` / `res_repack.py` round-trip is **byte identical** (verified by SHA1).

## 4. Scripts

- `Data\Scripts\<Language>\MainMission.dsc`, `Tutorial.dsc` — plain text, **loaded by the engine**
  (path template `Data\Scripts\%s\...`; `.dsc` is referenced, `.csc` is not).
- Block-structured scripting language. Quoted strings are of two kinds:
  - **display text** (translate): `SetMissionDescription("...")`
  - **logic identifiers** (never translate): event names `EnableEvent("TimePassed")`,
    `LastEvent_Type == "TimePassed"`, commands `EntityCommand("FaceThePlayer",...)`,
    modes `SetGlobalAIMode("Disable")`, unit types `CreateEntity(..., "Human", ...)`, etc.
- Translating logic identifiers is what breaks mission triggers ("完成任务不触发剧情").

## 5. Language mechanism

- Current language: registry `HKCU\Software\Primal\Dragon` value `language`.
- Assets are per-language by folder: `Data\Scripts\<L>`, `Data\Sounds\Speech\<L>`,
  `Data\Video\<L>`, `Data\Textures\Ui\...\<L>`.
- `Fonts.dat` / `Strings.dat` are installed per language group (observed: `[en de] [pl] [cs] [hu]`;
  Steam build ships a single English variant with `English/Russian/German`).
- Loose files under `Data\Textures\...` override the packed copies.

## 6. Textures

- TGA: uncompressed 24/32 bpp and RLE 32 bpp.
- DDS: DXT1 (535) and DXT5 (400), plus dimensions from 8x8 up to 1024x1024.
- Total 63.6 Mpix across 1884 textures.