[PR] Fingerprint Rewrite

[github_bot]

PULL REQUEST DETAILS

[security][rework][input wanted]

About the PR
- Fingerprints are now applied based on the arms themselves rather than being part of the mob.
- If the left and right arms have different fingerprints, the print will be applied based on the active hand.
- Human limbs use lowercase letters, while robotic limbs use hexadecimal fingerprints.
- Gloves now leave behind a partial fingerprint mask. Silver nitrate can be used to reveal partial fingerprints through gloves.
- Black & janitor gloves leave behind no partial prints. Most gloves will have a fingerprint mask with a 25% match rate. Insulated gloves have a 12.5% match rate. Latex gloves have a 6% match rate. Custom gloves will depend on the chemical resistance of the material. (Higher match rate is better for crime)
- Partial prints can be inputted into the forensics scanner for a list of potential matches from security records
- A bottle of silver nitrate can be found in forensics carts at round start.
- Fingerprints are no longer used for admin logs. Admins can now use a separate adminprints system that stores user's ckeys to obtain a chain of custody.
- Fingerprint report text is now more condensed by using multiple columns.

Why's this needed?
- Updates fingerprints to the new forensics system.
- Fingerprint system is now much more detailed.
- Admins now have their own type of forensics for more customized data collection.

Testing
<img width="821" height="194" alt="Screenshot 2025-10-12 044525" src="https://github.com/user-attachments/assets/ae8a35ba-e187-43a0-9636-6b059a9e1c6e" />

<img width="433" height="290" alt="Screenshot 2025-10-12 045035" src="https://github.com/user-attachments/assets/c9486612-037c-407f-9ba1-c84c7e3c5363" />

<img width="388" height="552" alt="Screenshot 2025-10-12 040411" src="https://github.com/user-attachments/assets/9a51e686-92cb-401c-b955-5f031ab15970" />

Changelog

Code:

changelog
(u)LorrMaster
(*)Fingerprints have been rewritten and are now based on the current arm(s) instead of the mob themselves.
(*)Partial fingerprints can be revealed using silver nitrate, varies depending on the type of glove.
(+)A bottle of silver nitrate can be found in forensics carts.

PULL REQUEST DETAILS

[Tessellation]

I'm a fan! Although admittedly it's mostly because I thought it was silly how easy it was to find the fingerprints of someone using latex gloves when that's like THE "leave no fingerprints" type of glove in media lol.

[LorrMaster]

Thanks! Just in case it isn't clear, a higher match rate is better for crime. 100% match rate means that it could be anyone and a 0% match rate means that you have the entire fingerprint. So even with no other evidence latex gloves will probably narrow the search down to a few suspects with the caveat being that you now need the chemical to do the analysis.

[flyingcow01]

Played with the changes on local for a while and although I'm a big fan of the idea in general, I'm worried that this implementation might make reliable forensics too difficult. Latex gloves are widely available in all public MiniMeds aside from there being a LOT of them in medbay. This would most likely make them the best choice for crime gloves and it would make the detective's job a lot more difficult with how little the partial prints gives away. There's also the case of the gloves leaving the same partial print on each touch (iirc now they reveal different parts of the print each time you grab/touch something, allowing you "piece together" a full print after some time). Overall I love the idea of the chemical spraying to reveal partials and making them arm-based, just got mixed feelings on the new partial masks.

[Vulwin_Gilran]

I feel like it would be better if it indicated the sequence for partial prints, like how currently for latex it will have nonsense $%$# intermixed with the actual prints letters like %#e$ which i prefer since it gives you an indication of its placement compared to the proposed method of just giving ...e... which doesnt really indicate where in the sequence the e occurs.

But its very cool still!

[LorrMaster]

Forensics impacts the sec/antag relationship, so these details are important. Partial print balance is a little finicky due to how the math works out, for example showing the exact placement of a single letter will incriminate 1/16 players. Showing the exact placement of two letters incriminates 1/240 players, so basically gives away who it is if you put in the (admittedly tedious) work of going through secmate. So the way I see it there are a few options to choose from.

1) Latex gloves reveal partial prints without the chemical, might be a good way to reveal the system for new players.

2) Have a way to "autocomplete" the minigame. So maybe inputting "..a..c.." into the forensics scanner gives you a full list of possible suspects from the security records.

3) Latex gloves reveal more characters to the point that doing the partial print minigame will probably give you an exact match.

4) Create a different system for revealing partial prints, if you have any suggestions. The current system uses the same 16 characters for each fingerprint placed without repetition.

[DisturbHerb]

it would be cool if the exact number of characters were rendered for partials, maybe use a monospaced typeface too for forensic data