The Nineteenth Byte

12:33 AM

0

Introduction Super Mario 64 has a heavily overcomplicated RNG, ably explained here by Pannenkoek. I thought it might be interesting to implement it. Challenge Implement the RNG function, except for the two special cases. Input and output are both 16-bit integers. The standard C implementation is ...

thejonymyster

@Neil most things in unicode should be combining characters

do we have a specific meta for "challenges should be self contained"

Zion mycelia adamancy

@thejonymyster No, because technically speaking, a challenge does not need to be self-contained. However, it's implied by our many metas/help center pages/etc. that say that a challenge must have a clear specification of what constitutes a correct submission

thejonymyster

fair enough :P i think it should be so im still saying it in my feedbacks

Bubbler

The C code is the spec in this case I think

Zion mycelia adamancy

Yeah, feedback can always include that a challenge should be self-contained, you don't necessarily need a source for that :P

thejonymyster

12:44 AM

right ofc i jsut wanted to have authority about it xd

@Bubbler i dont know C code :P

plus like.. cmon just write it out in english why make me jump through hoops

Bubbler

It's just a ton of bitwise manipulation, I don't think it can be explained better in plain English

Zion mycelia adamancy

The problem with writing out an algorithm in english is that it can be incredibly long. Pseudcode might be worth it

thejonymyster

pseudocode sounds ideal honestly yea

Bubbler

though I guess things like (uint8_t)xx can be changed to make the bitwise operation aspect clearer

Zion mycelia adamancy

For example, look at how long it takes me to explain 25 lines of Python code

Bubbler

12:48 AM

and a bit of parenthesizing

thejonymyster

a long challenge description is fine by me

Zion mycelia adamancy

A long challenge description isn't necessarily a bad thing, but when it can be short and concise, it should be

thejonymyster

sure, but what appears to be sparsely commented C code isn't a description

maybe im oppinionated and ppl wont mind except for me LOL

Bubbler

Set s0 to 0
Copy lower half of input to upper half of s0
Take bitwise XOR of s0 and input, and store it in s0

Do you really think it is more readable than the C code...?

thejonymyster

yes?

Zion mycelia adamancy

12:54 AM

I stand by that this style of C bitwise coding is poor style

thejonymyster

your comment about making it more "agnostic" is exactly what i was feeling but didnt know how to say, ty

like with the description sure its still complicated but i immediately know what each word is saying and telling me to do

Zion mycelia adamancy

It doesn't take much to figure out what & 0xFF00 does, but ^ 0x8180 or ^ 0x1FF4? Those seem like arbitrary magic constants to me that just make the code unnecessarily dense and confusing

thejonymyster

overall: should have sandboxed :')

Bubbler

Set s0 to 0
Copy lower half of input to upper half of s0
Take bitwise XOR of s0 and input, and store it in s0
Copy lower half of s0 to upper half of input
Copy upper half of s0 to lower half of input
Take lower half of s0, shift left once, XOR with input and store back to s0
Shift right s0 once, flip upper 9 bits, and store it to s1
if s0 is odd, calculate s1 XOR 0x8180; otherwise calculate s1 XOR 0x1FF4
and return the result

thejonymyster

i do enjoy mario 64 mechanics though

Zion mycelia adamancy

12:57 AM

A few minor edits being required doesn't mean it should've been Sandboxed

Bubbler

Well I'd argue that the two magic constants are what makes the RNG a RNG

Zion mycelia adamancy

Of course, I always recommend Sandboxing unless you've got a lot of experience, but almost every challenge will need a bit of editing on main

thejonymyster

you know what, reasonable

Zion mycelia adamancy

@Bubbler Fair enough, but when the rest of the code is a mess of bitwise commands, it's not especially easy to tell what's a "magic constant" and what is a "bit constant" (e.g. 0xFF00)

Bubbler

Usually the operands to & are regular bitmasks and those to ^ are magic

OldSandboxPosts

1:00 AM

Sandbox posts last active a week ago: Make an ASCII art arrow [code-golf] [ascii-art]

lyxal

1:37 AM

If y'all want to learn about some propositions and logic stuff, you should come join a lyxture

lyxal

2:53 AM

As to the above, the lyxture is over for now

Sandbox Posts

8:25 AM

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A: Sandbox for Proposed Challenges

Swap every two elements in the list every possible way Inspired by this question. Challenge Let L be a list of n distinct elements. Let P be the set of all pairs of positions in P. Let R be a result of applying a pair-swap operation on L by every pair in P in any order. Example: L = [1, 7, 8] P =...

thejonymyster

2:09 PM

Do we have a question abt resolving a bunch of competing cardinal/ordinal directions?

like the 2d version of bf optimizing >>><< to >

something like NE NW SW => NW

idk if N N N S should output different from N N S or something though

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