# `trackblock` File Specification

## `trackblock` File Layout

`trackblock` files contain a header, body with multiple segments and a footer.

* Header
* Body
    * Segments
* Footer

**Note:** The footer of each file contains 7104 bytes null bytes (`00`). This is considered normal. The reason for the file padding is unknown.

## `trackblock` Header

### Header Layout

| Offset | Length | Type | Description |
|--:|:-:|---|---|
| `0x00` | 1 | Unsigned Byte | File Index? |
| `0x01` | 1 | Unsigned Byte | File Index Repeated? |
| `0x02` | 1 | Unsigned Byte | Unknown. Values include `2f`, `08`. |
| `0x03` | 1 | Unsigned Byte | Unknown. Always `00` |
| `0x04` | 1 | Unsigned Byte | Unknown. Values include `01` and `00` |
| `0x05` | 1 | Unsigned Byte | Unknown. Values include `2c` and `cd` |
| `0x06` | 2 | Unsigned Short | Unknown. Always `00 00` |
| `0x08` | 4 | Unsigned Int | Unknown. Values include `00 00 00 00` and `00 00 00 10` |
| `0x0c` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x10` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x14` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x18` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x1c` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x20` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x24` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x28` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x2c` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x30` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x34` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x38` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |
| `0x3c` | 4 | Unsigned Int | Unknown. Always `00 00 00 00`. Padding? |

## `trackblock` Body

Each file covers an average of 7.42 hours (based on 26 files).

### Segments

Each file body is divided into 48 segments. Segments cover an average of about 10 minutes and contain an array of location and meta data

#### Segment Header

| Offset | Length | Type | Description |
|--:|:-:|---|---|
| `0x00` | 4 | Unsigned Int | Timestamp1 |
| `0x04` | 4 | Unsigned Int | Timestamp2 |
| `0x08` | 8 | | Padding |

#### Parameters

##### Timestamps

These values are not always equal. Possibly playtime vs playtime + idle time?

#### Segment Body

The segment body contains an array of 300 four-byte entries. There does not seem to be a set amount of time between each entry, but the time averages out to be around 2 seconds between each location logged.

| Offset | Length | Type | Description |
|--:|:-:|---|---|
| `0x00` | 4 | Unsigned Int | Entry |

Nintendo has compiled quite a bit of data into each entry. Each entry is a 32-bit unsigned integer describing coordinates and meta data (as flags).

The following big-endian value

```
Hex: 0x8E6ADF6E
Int: 2389368686
Bin: 0b10001110011010101101111101101110
```

would be decompiled in the following manner:

```
7 6 5 4 3 2 1  X Coordinate  0  Y Coordinate
1 0 0 0 1 1 1  001101010110  1  111101101110
```

| Bit | Length | Type | Description |
|--:|:-:|---|---|
| `0` | 12 | Unsigned Int | Y-coordinate |
| `12` | 1 | Boolean | `flag_0` Y-coordinate sign |
| `13` | 12 | Unsigned Int | X-coordinate |
| `26` | 1 | Boolean | `flag_1` Horizontal shift |
| `27` | 1 | Boolean | `flag_2` Y-coordinate sign |
| `28` | 1 | Boolean | `flag_3` Teleport? |
| `29` | 1 | Boolean | `flag_4` Player auto-placement? |
| `30` | 1 | Boolean | `flag_5` Death |
| `31` | 1 | Boolean | `flag_6` Horse Riding |
| `32` | 1 | Boolean | `flag_7` MainField or Dungeon / AocField |

#### Flags

| Flag | `0` | `1` | Description |
|--:|:-:|:-:|---|
| `0` | -y | +y | Mirrors point across the x-axis |
| `1` | `false` | `true` | Horizontal shift (`+4096`) |
| `2` | -x | +x | Mirrors point across the y-axis |
| `3` | `true` | `false` | Player auto-placement? |
| `4` | `true` | `false` | Teleport? |
| `5` | `true` | `false` | Death |
| `6` | `true` | `false` | Riding a horse? |
| `7` | `true` | `false` | `true` = MainField , `false` = Dungeon or AocField |

#### Parsing Algorithm

The following algorithm works for big endian

```c++
for (int int = 0; int < 300; int++) {
    // Read unsigned int from file into unsigned int data
    unsigned int y = data & 0xfff
    unsigned int x = (data & 0x1ffe000) >> 13

    unsigned int flag = (data & 0xfc000000) >> 26
    unsigned int flag_0 = (data & 0x1000) >> 12
    unsigned int flag_1 = (data & 0x2000000) >> 25
    unsigned int flag_2 = flag & 0b000001
    unsigned int flag_3 = (flag & 0b000010) >> 1
    unsigned int flag_4 = (flag & 0b000100) >> 2
    unsigned int flag_5 = (flag & 0b001000) >> 3
    unsigned int flag_6 = (flag & 0b010000) >> 4
    unsigned int flag_7 = (flag & 0b100000) >> 5
}
```