[LeapFrog] UDI files

[applecuckoo]

Hello! Yes, the topic sounds silly at first, but I have a bunch of unknown .udi files from the Transformers Rescue Bots game developed by LeapFrog. Initial research points to this being a CorelDraw file, but there seems to be no information on these .udis specifically.

RobotsTF_BG.zip

[ikskoks]

Try with offzip http://aluigi.altervista.org/mytoolz/offzip.zip

Like this:

offzip.exe -a RobotsTF_BG__page1.udi

Then open extracted DAT file in Texture Finder:

 

File format should be something like this:
 

// header (36 bytes)
4 bytes (char) - signature // "UDI\x00"
4 bytes (uint32) - version?  // 1
2 bytes (uint16) - image data offset
2 bytes (uint16) - bpp?  // 8
4 bytes (uint32) - UDI file size
2 bytes (uint16) - image width?
2 bytes (uint16) - image height?
16 bytes  - unknown

// data
x bytes - image data (compressed with ZLIB)

 

[applecuckoo]

Is this interlaced or something? The image looks split.

[BloodRaynare]

8 minutes ago, applecuckoo said:

Is this interlaced or something? The image looks split.

"Tiled" actually
Unfortunately unless you know how to Un-"tile" it, then that's what you're going to get from the image datas.

[applecuckoo]

Okay, bit of an update: I've figured out via some in-game XML files and some more checking that the files are actually stored as 4bpp. This makes more sense, especially since some of the elements I have stored locally looked a bit too transparent.

[piken]

Yes, they are 4-bits per channel. Does this look right, like anything in the game? (manually rewrapped the oddly sized 18x18 tiles using Aseprite) Your sample zip looks like a bunch of backgrounds, but if you have any others with actual sprites in them, that could be interesting to deduce the pixel format more conclusively? Showing r4,g4,b4,a4 below:

(actually it may be a4,r4,g4,b, which would show as purple instead)

Edited March 16, 2024 by piken

[applecuckoo]

Here's some more samples. I'm actually certain they're RGBA4444 since I managed to reproduce page 0 with the right colours using PVRTexTool. The only thing I'm curious about now is how to remap the tiles in a way that makes sense.

RobotsTF.zip

 

Edit: Seems like there is some overlap in the bottom two rows and the rightmost two columns. Working on the title screen right now!

Edited March 16, 2024 by applecuckoo

[piken]

15 hours ago, applecuckoo said:

I'm actually certain they're RGBA4444

Agreed, {r4,g4,b4,a4} because otherwise the colors looks wrong in RobotsTF__page8.udi, which is a clearer case because of the police lights.

15 hours ago, applecuckoo said:

The only thing I'm curious about now is how to remap the tiles in a way that makes sense.

Maplestory M used an interesting block arrangement using 3 textures, one for pixels, another for palette, and a 3rd for the tilemap (Xentax thread https://web.archive.org/web/20231012075405/https://forum.xentax.com/viewtopic.php?t=26127). There's no palette in this case, but the concept should apply here too. Maybe you can find the tilemap elsewhere 🤞.

I was curious about the LeapFrog LeapPad to see if it had any novel pixel formats, but I couldn't find any real hardware information (besides screen resolution) nor an SDK for it 😞. I did find an alternate firmware (Retroleap), but I didn't want to dig through that large codebase to try to figure out capabilities ⛏️.

Edited March 16, 2024 by piken

[applecuckoo]

9 hours ago, piken said:

Maybe you can find the tilemap elsewhere

So I managed to figure out the pixels are really 16x16, since the rightmost two columns and the bottom two rows contain redundant data. Basically at this point it was just opening a new Aseprite file and putting together a giant jigsaw puzzle. So that's how I got these two title screens!

Edited March 16, 2024 by applecuckoo