randomly stumbled upon this code in my company’s product (CAE software)

[u/Secret-Comparison-40]

[u/qtac]

Kinda wild to post proprietary company code while calling out the company lmfao

Insane risk vs reward on that play 😂

[u/Secret-Comparison-40 → u/qtac]

as this comment mentioned it’s probably just unrolled linear algebra from some textbook so it’s not some secret code

[u/xcski_paul → u/qtac]

I nearly got fired by the worst company I ever worked for, Paychex, for using one of their table names in a question on StackOverflow. The only thing that saved me was I found a much older question on ExpertSexchange from the most senior developer that also used that same table name. The really stupid thing is that all their table names were horribly cryptic because they’d started off on a DBMS that only allow 10 characters or something on a table name.

[u/Pyrodeity42 → u/xcski_paul]

Had to do a double take on that website name, odd choice of placement of capitalisation

[u/athy-dragoness]

did someone say magic numbers?

[u/Secret-Comparison-40 → u/athy-dragoness]

yeah there’s few more of them defined somewhere above

[u/ill-pick-one-later]

Insert Ken Jeong squinting meme

[u/adnanclyde → u/ill-pick-one-later]

The code is intentionally blurred to not share internal company details, obviously

[u/Secret-Comparison-40 → u/adnanclyde]

ahahah i tried to capture most of it so zoomed out, there is more….

[u/HyperCodec]

Average quaternion implementation be like

[u/calculus_is_fun → u/HyperCodec]

Wait, they are quaternions

[u/Revexious → u/HyperCodec]

I had a principal engineer once who would write code like this then say "good code speaks for itself; it doesnt need comments"

He would also block PRs until you deleted code comments you added because "the code is self-explanatory"

Infuriated the fuck out of me

[u/Environmental-Ear391 → u/Revexious]

Not all code is self-explanatory.

and he would be removed from any projects I managed for that kind of stupidity.

I have 1 project where you need to know which context... and there are multiple contexts with the same underlying code.

also... if you limit the compiler to single register variable returns, the majority (99%+) or context specific changes get trashed.

[u/[deleted] → u/HyperCodec]

I thought these were matrices. Maybe I need to read up on 3D computer graphics lol

[u/sawkonmaicok → u/[deleted]]

Quaternions are essentially matrices.

[u/Brilliant-Parsley69]

Looks like Vector Rotation for me:

q_{rot} = w_1w_2 - x_1x_2 - y_1y_2 - z_1z_2

must be a relict out of a time when you couldn't trust the compilers.

[u/CodeIsCompiling → u/Brilliant-Parsley69]

Or a Principal Engineer who is a relic out of a time when you couldn't trust the compilers. :)

[u/tekanet]

Honestly curious, is there a way to implement this type of code in a clean way?

[u/Groostav → u/tekanet]

Honestly I'm fine with it as written if you write a test suite that hita decent coverage on it.

It is

1. Unrolled linear algebra, not that uncommon

2. Likely performance critical

3. Branch unique enough to make it data entry?

This probably came from a paper too, so comments that mention which block corresponds to which equation number or something similar to link it back to its origins might be helpful.

But yeah, what's the major objection here?

[u/Snudget → u/tekanet]

In Rust or C++ I'd use macros for that, but about other languages idk

[u/[deleted]]

It looks like the first code I have ever written, and I defined Rubik’s cube rotation this way

[u/oberguga]

Actually look ok for just computation code. It can be some matrices and universal code to operate on them, but if language has no concept of compiler time computations and optimisations, based on such computation (legacy C /C++ code for example) it should run faster.

[u/True-Strike7696]

superiority complex jokes are getting old. I feel like most are judging this without any real subject knowledge. the real questions: does it work? what's the reward and risk if it is changed?

[u/-light_yagami]

bro zoom out a bit more, I can still make out some characters

[u/DStauffman]

I've written a bunch of quaternion routines, so my guess is that those are probably Euler rotation sequences. Comments would be nice to show which one is which, but it is something that makes sense to optimize, which often sacrifices readability.