ASCII fluid dynamics -- IOCCC2012 endoh1.c
Why Hacker News recommends it
Commenters repeatedly point to it as an astonishing, beautiful piece of obfuscated-C code golf.
What it is
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.
Recommended by 3 HN commenters across 3 different months, 2018 to 2025.
What Hacker News said
Strong rec yung_steezy · 2022-05 · on “An uroboros program with 100 programming languages”
Yusuke Endoh is a god amongst men. His C program which creates an approximation of fluid dynamics from any text input is insane - [this video]
Strong rec daptaq · 2022-10 · on “A Ruby program that generates itself through a 128-language quine loop”
This was written by Yusuke Endoh, who also wrote this submission to the IOCCC that I remember being arguably more astonished when I saw it for the first time: [this video] (ASCII fluid dynamics).
Strong rec 6502nerdface · 2023-02 · on “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]
Cites bewuethr · 2018-05 · on “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]
Cites tromp · 2024-05 · on “Fast real time fluid simulator based on MPM algorithm”
The IOCCC also featured a very concise fluid simulator [1] [2], which can be seen in action in this video [3]. [1] [LINK] [2] [LINK] [3] [this video]
Cites pwnfunction · 2025-10 · on “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]