alt.hn

1/12/2025 at 3:13:14 PM

Bad Apple but it's 6,500 regexes that I search for in Vim

 https://eieio.games/blog/bad-apple-with-regex-in-vim/

by vortex_ape

1/12/2025 at 5:13:23 PM

Hah, trust nolen to 1,000x something :))) I have used similar tactics in the past, but separately and definitely not in one day! For the interested:

- Bad Matrix (tput blocks to the terminal): https://www.evalapply.org/posts/bad-matrix/

- Animating Text Art in Javascript (print text into fixed grid, flipbook-style): https://www.evalapply.org/posts/animate-text-art-javascript/...

- oxo (format and print tic-tac-toe board to terminal, so I can regex-match for win/loss/draw results): https://github.com/adityaathalye/oxo/blob/7681e75edaeec5aa1f...

But, I mean, that Bad Apple takes the cake!

(edit: add missing link)

by adityaathalye

1/13/2025 at 5:42:44 AM

Ahaha `oxo` is an unhinged project to actually execute. Thanks for sharing all of these projects.

Brb forking and integrating ascii-text third party ads

by DiggyJohnson

1/14/2025 at 10:51:25 AM

Thank you for the kind appreciation. ascii-text third party ads adds a whole commercial dimension... Now, to make it really 21st century, someone can replace the "randumb" computer player with an LLM adversary :)

by adityaathalye

1/12/2025 at 5:32:55 PM

The tech demo that really made me fall in love with Bad Apple was getting it to run on the NES.

https://somethingnerdy.com/downloads/

Here it is running from my Everdrive.

https://inversethought.com/jordi/video/badapple.mp4

Yes, with full audio. It's about one gigabyte of data. On a system where the typical game size is no more than a couple hundred kilobytes, and your CPU only has three 8-bit registers for you to do any calculation with.

by jordigh

1/12/2025 at 10:25:24 PM

Very cool. Having done a bit of NES dev I can imagine this wasn't super straightforward to make performant for the graphics, given you can typically only have a few sprites on a row before the NES starts to 'dissolve' them (not sure the term).

I wonder if it's using the background tile map for this instead of sprites, though that's also an impressive amount of graphics bandwidth.

> with full audio playback rate (44.2kHz)

The audio being so clear is also impressive, is that something that the card extends? IIRC the PCM channel on the NES isn't anywhere near that bitrate, and is also 8-bit sample size.

by junon

1/12/2025 at 11:48:39 PM

The channel can either play back delta-modulation samples from memory, or you can directly set the output as a 7 bit value.

So by burning a lot of CPU cycles, you can keep up a perfectly good sample rate using the latter method.

by Dylan16807

1/13/2025 at 6:46:21 PM

The bitrate of the PCM is determined based on how quickly you can write a byte to the register. The fastest you could write general data is once every 6 cycles, which gives ~298 MHz of sample rate, so 44.2 kHz is easily doable if that's all you want to do with the CPU.

by godd2

1/15/2025 at 12:16:32 PM

Do you mean 298 KHz? I thought the 6502 on the NES was slightly over 1MHz

by junon

1/13/2025 at 6:49:06 PM

> I wonder if it's using the background tile map for this instead of sprites

Yes, it's all background tiles being loaded continuously from the SD card. We created the tiles with a custom tile de-maker.

by godd2

1/14/2025 at 9:39:43 PM

Very cool, thanks for the info :)

by junon

1/13/2025 at 2:08:06 AM

This is really neat - did you do any kind of writeup on it? I’d love to read it if you did.

by eieio

1/13/2025 at 7:02:13 AM

That is glorious!

by panzi

1/12/2025 at 5:11:13 PM

Regarding the Vim macro that ends by going to the next line to be "replayable": You can also use the following command to run the macro once per line:

        :%norm @q

by rav

1/12/2025 at 5:23:56 PM

oh wow, TIL, I'm pretty surprised I didn't know this trick!

back when I was vim golfing the normal solution was to make the macro recursive. So you'd record your macro, and you'd end it with '+@q' (move to next line and run the macro again). Then you run the macro once and it runs over every line.

This ends up being really efficient in terms of keystrokes but in practice I think it's hard to think about and not very ergonomic, so I don't end up using it much. But it's a fun trick for golfing.

by eieio

1/12/2025 at 5:50:28 PM

There's also the no-macro solution where you just use ":%norm [series of keystrokes]" to run the given keystrokes on each line, but that comes with the added difficulty of not giving any visual feedback of what the keystrokes will do before you submit the entire line.

One thing to keep in mind is that ":%norm" will place the cursor at the start of each line, before any indentation, whereas the trick of ending the macro with "+" will place the cursor at the start of each line after the indentation. But this can be worked around with ":%norm ^@q", using ^ to skip indentation before running macro q on each line.

by rav

1/13/2025 at 3:20:14 AM

Related to that, macros are just recorded into normal registers. You can get it out with:

  "qp
Edit it, and put it back into the register with

  "qdd

by Izkata

1/13/2025 at 6:51:05 PM

Heads up - you should use "qD instead of "qdd to avoid an extra newline at the end of the register contents. (In fact the current Vim 9.1.954 behavior seems a bit odd in that it moves the cursor down, but not to the start of the line, as if j is pressed... Seems like a bug to me.)

by rav

1/13/2025 at 10:59:26 PM

And D goes from cursor to end of line instead of the whole line. Wasn't sure how complicated I wanted the description to be.

by Izkata

1/12/2025 at 8:56:30 PM

Most often when I run a macro it's to change lines matching searches, so I just start the macro with the search (or `n` if the macro doesn't do additional searches) then I end the macro with `@q` (or whatever register), then execute the macro. I don't think I've ever had occasion to run a macro on every line, though I've had occasion to run macros over line ranges (but still, all matching a specific pattern).

by cryptonector

1/13/2025 at 7:30:06 PM

To run a macro on the start of each line matching your search, you can use:

    :g//norm @q
Here, g// repeats the most recent search, and norm @q runs the q macro on each matched line. This is not quite the same as starting the macro with a search, since the cursor is at the start of the line and not at the start of the match, but it's often good enough.

You can also restrict it to just the matches inside a range of lines: First select the lines in visual mode, then type :g//norm @q, which will cause Vim to insert a range before g, as in: :'<,'>g//norm @q, which means "between line '< and '>, find lines containing a match of the most recent search, and run @q on each such line".

by rav

1/14/2025 at 12:27:59 AM

Thanks!

by cryptonector

1/12/2025 at 5:23:14 PM

These were on sale last month

https://us.govee.com/products/govee-curtain-lights

and my understanding is that you can upload an animated GIF to it... I just added making a "bad apple" GIF for it to my Kanban board though I don't know how much memory the device has and how well I can get it to work.

(Sometimes that part where Remmy Scarlet spreads her wings still makes chills go down my spine)

by PaulHoule

1/12/2025 at 7:48:55 PM

Someone definitely need to shoot Bad Apple using a kanban board!

by nokeya

1/12/2025 at 11:06:39 PM

Another project on my Kanban board is a plan to big spread of Touhou characters linked with QR codes. Here's a prototype card

https://bsky.app/profile/up-8.bsky.social/post/3lbqfh7pesc2x

and the spreads I make are like

https://bsky.app/profile/up-8.bsky.social/post/3latxcwmkpk2w

I have a list of 20 that I need to fill out a little (somehow I missed Koakuma) and then I have to have my image sorter find a good set of images that fit together stylistically. (A friend of mine was talking about how RA's in dorms would make picture sets for all the rooms, seemed to me Touhou would be the ultimate basis for this)

by PaulHoule

1/13/2025 at 8:02:57 AM

I've done this with Twinkly lights, but the lights sadly don't have enough memory to run more than a few seconds.

by a_t48

1/13/2025 at 8:43:53 AM

I have a GIF of Bad Apple at 64x32, just under 1MB.

Big shout out to https://ezgif.com/ !

by panki27

1/13/2025 at 3:22:30 AM

I have one of these curtain lights and they are great!

by nl

1/13/2025 at 12:34:34 AM

I never get tired of Bad Apple. The best thing on the internet. And almost every time I get somewhat jealous I didn't come up with that idea myself.

Also, I really like how footnotes are implemented in this blog. I guess I'm gonna steal it.

by krick

1/13/2025 at 1:43:31 AM

I stole the footnotes from my very talented friend Jake (https://jakelazaroff.com/), whose work you might have seen on here in the past. Note that they’re sidenotes on large screens but on small ones they swap to inline footnotes that expand when you click on them.

Anyway steal away!!

by eieio

1/12/2025 at 5:04:06 PM

For the rectangle minimization problem: your problem seems to differ from the one discussed on StackOverflow in that the SO thread discusses partitioning into non-overlapping rectangles, while your Vim project allows overlap.

I wouldn't be surprised if your problem turns out to be much easier to solve optimally.

by sltkr

1/12/2025 at 5:44:29 PM

Actually, from an algorithmic standpoint it's the opposite: the minimum cover problem (where overlap is allowed) is NP-hard whereas the minimum partition problem (where overlap is NOT allowed) has polynomial-time algorithms. "An Algorithm for Covering Polygons with Rectangles" by Franzblau and Kleitman 1984: https://core.ac.uk/download/pdf/82333912.pdf

However, that's of course just an academic tangent - the theoretical results don't necessarily imply that one problem is easier than the other when you're just getting something to work for an afternoon project.

by rav

1/12/2025 at 5:07:31 PM

oh this is a really good point! You're totally right, I had completely skipped over the fact that the rectangles were allowed to overlap. I think I'm probably done with this project / I'm pretty happy with the solution as it stands, but I think you're right that this simplifies the problem considerably. Thanks!

by eieio

1/12/2025 at 10:23:29 PM

I think my attempt would've been to flood fill to create an ordered list of spans, then use roughly the same method as the Lebesque integral, using the data from the flood fill as the function.

by vidarh

1/12/2025 at 5:29:25 PM

The parallel candidate solution generator is such a good idea, but it usually takes me a long time to realize I do not need to make the uber algorithm. Just one-more-tweak, and I know that I can make this solution work in all cases!

by 3eb7988a1663

1/12/2025 at 8:23:03 PM

it's probably my single favorite trick for making a prototype performant enough! I'm delighted every time that it works.

but agree that it can be really hard to take a step back and realize that you can employ it instead of writing something "perfect"

by eieio

1/12/2025 at 5:14:50 PM

This is pretty cool! I like the creativity. The games this is based on are pretty good too. Danmaku are hypnotic

by codeguro

1/12/2025 at 5:22:16 PM

The people running Doom or Bad Apple in different unexpected ways are such champs.

There are some really interesting ones, like running Doom on a pregnancy test.

by 29athrowaway

1/12/2025 at 5:25:00 PM

Strongly disagree on that one; it was basically Doom on some random microcontroller stuffed into a pregnancy test shell.

by saagarjha

1/12/2025 at 5:33:49 PM

The pregnancy test was the greatest drama to ever hit the r/itrunsdoom community.

by jordigh

1/12/2025 at 8:15:46 PM

Good point

by 29athrowaway

1/12/2025 at 5:46:55 PM

I remember watching the Soccer World Cup 2006 at work. I logged in my home server via ssh and could watch it in the terminal. Not enough bandwidth for something else.

by manosyja

1/12/2025 at 6:22:29 PM

As the author admits, it's Vim but it's not regexes. It's "searching" for screen coordinates.

It's drawing in Vim, but not pattern matching.

by lupire

1/12/2025 at 4:02:39 PM

Roughly how long did that take?

by perpetualchange

1/12/2025 at 4:12:14 PM

Hi! I'm the author.

Like jchw said, this was a single-day project (although I did the writeup for it the next day).

I went from 0-prototype in one sitting; I think that was around four or five hours of work? Then I went home, had dinner, and spent maybe three hours optimizing and cleaning it up.

edit: I should say, i have done a lot of dumb things like this and I'm pretty sure it would have been at least a week of work for me 2 years ago. "making the computer do dumb stuff" is a skill like any other!

by eieio

1/12/2025 at 4:15:29 PM

Thanks for taking the time to respond, pretty impressive stuff!

by perpetualchange

1/13/2025 at 7:06:20 AM

Doing that in a single day is impressive. Took me two days to do my much simpler version that just prints it using Unicode symbols for legacy computing.

by panzi

1/12/2025 at 4:05:29 PM

From the article:

> I didn’t have the time to find a good general-purpose algorithm: I was working on this the night before weekly presentations at the Recurse Center and I wanted to present it the next day!

...

> I built this in a single day

No estimate of hours, though.

by jchw

1/12/2025 at 4:11:21 PM

My browser was apparently bugged, and it didn't show the article the first time... I see it now and am going through it. Thanks for mentioning! :)

by perpetualchange

1/13/2025 at 7:12:30 PM

Awesome. One can never have enough Bad Apples!

by sharyphil

1/12/2025 at 4:16:50 PM

... this is why we love bad apple!

by GZGavinZhao

1/12/2025 at 4:41:00 PM

[flagged]

by yeahbutonly

1/13/2025 at 1:15:20 AM

[dead]

by laurentpm

1/13/2025 at 1:22:36 AM

Nah what ads in HN is crazy

by thatxliner

1/12/2025 at 4:05:59 PM

[dead]

by summeroflove20

1/12/2025 at 5:06:53 PM

[flagged]

by wistle

1/12/2025 at 5:26:49 PM

Touhou is just a bullet hell game, relax. Being this upset over it is more a reflection where your mind is at rather than everyone else's.

by codeguro

1/12/2025 at 5:44:32 PM

[flagged]

by wistle

1/12/2025 at 6:40:24 PM

Can you say what exactly it is that puts it in the genre of lolicon?

by fluoridation

1/12/2025 at 6:05:29 PM

Either you can't distinguish bullet hell games from porn or you're projecting.

by codeguro

1/12/2025 at 5:13:53 PM

Seems better than using a literal Playboy centerfold.

by saagarjha

1/12/2025 at 5:16:52 PM

Both are objectionable.

by wistle

1/12/2025 at 5:26:09 PM

Ok, but one of them is literal pornography, and one is…clearly you actually know what the word "hentai" is given you have used it in your comment. What part of this is hentai?

by saagarjha

1/12/2025 at 5:45:54 PM

[flagged]

by wistle

1/12/2025 at 7:48:13 PM

It's not though? It's a music video for a 100% safe for work video game where small sprites of witches and yokai (supernatural entities/spirits) play what is in effect a much more complicated version of space invaders.

There is nothing even remotely close to sexual or NSFW in it.

https://www.youtube.com/watch?v=AY7QEEnSGVU

by jacoblambda

1/13/2025 at 2:35:32 AM

[flagged]

by sososocontext