WiiU.md

Another World 20th Anniversary Edition (WiiU)

Technical notes on the WiiU release.

Resource Bundle

The content directory of the game contains the music files (.OGG) and one resource bundle (.BIN)

content/
├── archive.bin
└── game
    └── OGG
        ├── amb5001.ogg
        ...
        └── amb5011.ogg

The file archive.bin contains the game data files.

The offset to the entries table and the number of entries are stored at the end of the file as 32 bits big endian integers (BE32).

Resource table entries format.

Field	Type	Details
File name	\0 terminated string	File path
Uncompressed file size	BE32	File size after decompression
File size	BE32	File size in the resource bundle
Data offset	BE32	File data offset in the resource bundle
Flags	BE32	Either 0 or 1

Data is compressed with LZ4.

Data Files

File	Details
game/awt/data1728x1080/	1080p texture backgrounds
game/bmp/data1280x800/	800p texture backgrounds (with a corrupted or incomplete palette ? maybe left-over)
game/dat/*mac	bytecode
game/dat/*mat	polygons (shapes)
game/dat/*pal	RGB444 palette colors (Amiga)
game/txt/*txt	strings ('Good evening professor.')
game/wgz_mixed/*wav	sound files

The 20th anniversary editions of Another World on consoles use higher resolution graphics than the Linux/Mac/Windows releases (1080p vs 800p).

Textures

The .awt (Another World Texture ?) files are the background pictures. The image pixels are stored as uncompressed RGBA (4 bytes). The file has a 12 bytes footer. Image dimensions are stored as 16 bits big endian integers (BE16).

08 08 08 08 : RGBA color component depth ?
BE16        : aligned width
BE16        : height
BE16        : width
BE16        : height

Game Code

The game bytecode contains two variants, one for the original low-resolution (320x200) and another one for 'HD' (1280x800).

Name	Part	Files
Intro	16001	intro2011(hd).mac/.mat
Eau	16002	eau2011(hd).mac/.mat
Prison	16003	pri2011(hd).mac/.mat
Cite	16004	cite2011(hd).mac/.mat
Arene	16005	arene2011(hd).mac/.mat
Luxe	16006	luxe2011(hd).mac/.mat
Final	16007	final2011(hd).mac/.mat

The only difference between the 'SD' and 'HD' bytecode files appear to be related to the polygons offsets, as expected.

$ diff -u intro2011.mac.asm intro2011hd.mac.asm
...
-033A: (FA) drawShape(code=0xFA, x=160, y=100); // offset=0xF5F0 (bank1.mat)
+033A: (FB) drawShape(code=0xFB, x=160, y=100); // offset=0xF608 (bank1.mat)
 033E: (18) playSound(res=44, freq=15, vol=63, channel=2)
...

An example of polygons upscale (SD vs HD .mat shape) :

Bytecode Variables

The game engine communicates with the game code via special variables.

Index	Details
0xBF	Game difficulty (0 to 2)
0xDB	Enable sounds preloading (resource >= 2000)
0xDE	Enable playback of remastered sounds (set to 0 when running the game in original low resolution)

Debugging Information

The .elf executable has a symbol table section.

$ rpl2elf AnotherWorld_WiiU.rpx
$ readelf -S AnotherWorld_WiiU.elf
...
  [23] .symtab SYMTAB c0000000 301bf0 02ac90 10 A 24 24411 4
...

$ readelf -sW AnotherWorld_WiiU.elf | tr -s' ' | cut -d' ' -f9 | c++filt
...
CInterpret::LoadGamePart(int, int)
CInterpret::InterpretAll(void)
CInterpret::Interpret(unsigned short)
CInterpret::HandleControl(void)
...
CDisplay::LoadImage(char const *, unsigned char *, int *, int *)
CDisplay::LoadPal(char const *, unsigned int *)
CDisplay::SetWorkScreen(int)
CDisplay::ComputePalette(void)
CDisplay::SetScreen(int)
CDisplay::FillScreen(int, unsigned char)
CDisplay::CopyScreen(int, int)
CDisplay::LoadImage(int, unsigned char *, int *, int *)
CDisplay::DrawImage(int)
CDisplay::PrintAt(int, unsigned short, unsigned short, unsigned char)
CDisplay::DrawScaledPoint(int, int, unsigned char)
CDisplay::DrawShapeHD(unsigned char *, float, float, unsigned short, float, unsigned char)
CDisplay::DrawHead(int, int, bool)
CDisplay::DrawShape(unsigned char *, int, int, unsigned short, unsigned char)