Technical Reference

Detailed documentation of DOKAPON! Sword of Fury file formats, discovered through reverse engineering.

Overview

This section contains reverse-engineered documentation of the game’s proprietary file formats. These technical details form the foundation of the C#/.NET 8 modding toolkit (DokaponSoFTools) and are essential for building tools, understanding asset pipelines, and creating mods.

All format implementations live in the DokaponSoFTools.Core library under the DokaponSoFTools.Core.Formats and DokaponSoFTools.Core.Compression namespaces.

File Formats

LZ77 Compression

The compression layer used across multiple file formats. Three distinct variants exist in the game:

FlagByte — flag-byte-per-8-tokens scheme; used for SPRANM and TEX files
TokenStream — per-token bit-flag scheme; used for MDL model files
Cell — separate flags/data streams with token count; used for MPD map files

All three share the same 16-byte LZ77 magic header but are distinguished by their header field layout.

SPRANM Sprite Animation Format

The sprite animation format for 2D graphics: character portraits, UI overlays, title screen elements, and effects.

Two file variants: Self-contained (with embedded PNG) and Runtime/Player (no PNG, uses PartsColor)
Optional LZ77 FlagByte compression layer
Section-based structure: Sequence, Sprite, SpriteGp, TextureParts (with Texture/Parts/Anime sub-sections), ConvertInfo
Rendering pipeline: Sequence → SpriteGroup → Sprite → Part → UV-mapped pixel region
Bottom-right corner positioning model for sprite pieces

MPD Cell Map Format

Map and environment data stored in a Cell container format.

Cell container header with grid dimensions and record table
LZ77 Cell variant compression (optional)
Named chunk system: Map (cell grid), TextureParts (texture atlas + UV parts), Palette (indexed color tables)
Cell records encode part index and rendering flags in three 32-bit values
Map values index into the record table which indexes into the parts atlas

PCK Sound Archive

Binary sound archive used for all game audio.

Two sections: Filename (name lookup) and Pack (data blocks)
Ogg Opus audio (OggS magic = Opus codec)
16-byte-aligned sound data with 8-byte section alignment
Four known archives: BGM.pck, SE.pck, Voice.pck, Voice-en.pck

Game Text Format

UTF-8 text strings embedded in the game executable.

Start marker \p (0x5C 0x70); end markers \k, \z, next \p, or null byte
15+ control codes for display control, paging, and special characters
Format specifiers for variables (%s, %d), colors (%Nc), positioning (%Nx, %Ny), and button icons (%NM)
Import uses offset:maxlength pairs; text is null-padded and never grown beyond MaxLength

TEX Texture Format

Standalone texture container (also embedded inside SPRANM and MPD files as the TextureParts chunk).

40-byte header with flags and dimensions
Storage: raw PNG bytes (0x4000 flag) or LZ77-compressed indexed pixel data (0x0080 flag)
Followed by Parts and Anime sub-sections

HEX Patch Format

Binary patch files for modifying the game executable.

Sequence of [offset: int64 BE][size: int64 BE][data: N bytes] records
Tool performs conflict detection (same offset, overlapping ranges) before application
Automatic backup creation; supports multi-file patch sets

Asset Pipeline

Game Assets
├── Audio
│   └── PCK Archives (BGM.pck, SE.pck, Voice.pck, Voice-en.pck)
│       ├── Filename section  (name lookup)
│       └── Pack section      (Ogg Opus data, 16-byte aligned)
│
├── 2D Graphics
│   ├── SPRANM files          (sprites, UI, title screen)
│   │   ├── [optional] LZ77 FlagByte compression
│   │   ├── Sequence section  (animation frames)
│   │   ├── Sprite section    (piece placement)
│   │   ├── SpriteGp section  (frame → sprite set)
│   │   └── TextureParts      (PNG + UV parts)
│   └── MPD files             (map tiles, environments)
│       ├── [optional] LZ77 Cell compression
│       ├── Cell header       (grid dimensions)
│       ├── Record table      (tile → part mapping)
│       └── Chunks: Map, TextureParts, Palette
│
├── Text
│   └── Embedded in game EXE  (UTF-8, \p-delimited)
│
└── Binary Patches
    └── HEX files             (offset/size/data records)

Common Structures

LZ77 Header (16 bytes, shared magic)

All compressed files begin with LZ77 (0x4C5A3737). The interpretation of bytes 0x04–0x0F differs by variant — see LZ77 Compression for details.

Section Header Pattern

SPRANM sections and PCK sections both use a fixed ASCII name padded to 20 bytes followed by a 32-bit size field. This pattern appears throughout the engine’s asset formats.

8-byte Alignment

Section boundaries throughout SPRANM and PCK files are aligned to 8-byte boundaries with zero padding.

Tools Reference

Tool / Feature	Formats	C# Class
Asset Extractor	.spranm, .mpd, .tex, .fnt	`AssetExtractor`
Map Explorer	.mpd	`MapRenderer`, `CellContainer`
Animation Viewer	.spranm	`SpranmDocument`, `SpranmRenderer`
Voice Tools	.pck	`PckArchive`
Text Tools	game exe	`GameText`
Hex Editor	.hex + exe	`HexPatch`

Research Notes

This documentation is based on community reverse-engineering efforts combined with implementation experience from the C#/.NET 8 rewrite of the toolkit. Some edge cases and file variants may not be fully documented. Join our Discord to discuss ongoing research.