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Frame from ASCII fluid dynamics -- IOCCC2012 endoh1.c Plays via YouTube's privacy-enhanced embed

ASCII fluid dynamics -- IOCCC2012 endoh1.c

Yusuke Endoh
Demos
YouTube
3 HN users recommended this demo3 months2018–2025 score 4.5
Years with an HN recommendation, 2007–2026

Commenters repeatedly point to it as an astonishing, beautiful piece of obfuscated-C code golf.

A 3-minute demo of a tiny IOCCC 2012 winning C program that simulates fluid dynamics in an 80x25 terminal, using any text (including its own source) as input. The video shows the simulation running to Handel's Water Music.

“truly a work of art” (HN, 2023)

3 strong recommendations · 3 citations · Demos

6 Hacker News comments

From the HN archive; up to 20 kept per video, favoring different commenters. Recommendations first.

@6502nerdface Feb 2023 Strongly recommends
on HN thread 2D Liquid Simulator with Cellular Automaton
My favorite 2D liquid simulator is this IOCCC2012 submission [1]... simply astonishing. That is the source file shown at the beginning of the video... it compiles without warnings, runs a full blown fluid dynamics sim with surface tension and everything, can take itself as its own input... truly a work of art. [1] [this video]
Compact C source runs full fluid sim and can take itself as input.

Citations, criticism and jokes

@bewuethr May 2018 Cites it
on HN thread Asciinema – Record and share your terminal sessions
These remind me of the ASCII fluid submission [0] at IOCCC 2012 [1] by Yusuke Endoh. The source [2] itself can be used as an input to the program (see video [3]), and he also made a colour version [4]. [0]: [link] [1]: [link] [2]: [link] [3]: [this video] [4]: [link]
Demo of the IOCCC ASCII fluid program using its own source as input.
@pwnfunction Oct 2025 Cites it
on HN thread Show HN: ASCII Drawing Board
is this opensource? adding a cool fluid simulation to whatever you draw would be really fun. its like one of those ioccc vids - [this video]
Cited as an example of fluid simulation applied to ASCII drawings.

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