Landon Curt Noll
f29b37e49a
Prepare for the winners of **IOCCC28**. > However these are not the 2024 droids you are looking for. :-) The HTML menu (both JavaScript and non-JavaScript) has been updated. The `Status -> Rules and guidelines' have been replaced with two separate menus `Status -> IOCCC rules` and `Status -> IOCCC guidelines`. Added a new top level `social.html` page: built from a new `social.md`. Sorted rules for building specific web pages in the top level `Makefile`. Added `make social` to make the `social.html` page from `social.md`. The `bin/gen-top-html.sh` now is able to process a argument of **social** to process the new top level `social.html` page. Changed `bin/gen-top-html.sh` VERSION from "2.0.0 2025-03-13" to "2.0.1 2025-07-25". Below `About -> Home page` a new `About -> IOCCC social media` menu item as added. Because the menu change touched every HTML file, we changed the general copyright date range for HTML files from "1984-2024" to "1984-2025" due to the extensive changes made for **IOCCC28**. Those markdown files that were modified in 2025 had their copyright date range also changed from "1984-2024" to "1984-2025". Rebuilt tarballs and sitemap due to the extensive HTML rebuilding. Ran `make update` to perform the above.
To build:
make
To use:
./eastman
NOTE: to restore your cursor in your shell, try reset.
Try:
Run the program. Quit it (ctrl-c/intr). Resize your terminal window. Run it again. Try doing this a number of times with different sizes each time.
./eastman
NOTE: to restore your cursor in your shell, try reset.
Judges' remarks:
This round program will generate a classic spherical result!
You will need a terminal capable of displaying coloured ANSI characters (for example an xterm or a Terminal.app window in macOS).
You might also want to turn off any scrollback history. The program will size itself to the initial geometry of your terminal.
If you are ambitious, make the font really small and the window really large for hi-res graphics!
Author's remarks:
This program uses ANSI graphics to recreate the classic Boing Ball demo from the Commodore Amiga. See https://www.youtube.com/watch?v=-ga41edXw3A if you aren't familiar with it. Back in its day, this demo inspired lust and awe in geeks around the world.
The graphics are raytraced, with procedural textures on the ball and the back wall. I did cheat a little to simplify the calculations: it uses a parallel projection, but textures the back wall to look as if there were a floor being viewed in perspective. The shadow is also just part of the texture, not an actual raytraced shadow.
This program automatically adapts to the size of the terminal it is running in, so try enlarging the window to get higher resolution. Don't resize while the program is running, though. It only checks the size once, when it starts up.
To compile:
cc -lm eastman.c
Portability
It should be completely portable. I've tested with gcc on Mac OS X 10.7 (Lion) and Fedora 10. I would expect it to work in any Unix-like environment.
Obfuscation
I have merged expressions wherever possible, making extensive use of ternary operators, commas, return values of assignment operators, etc. The entire raytracing computation, include ray intersection tests and procedural texture evaluations, is a single expression involving 41 operators.
Variables are named alphabetically in the order they are declared.
The third argument to ioctl(2) should really be a struct winsize, and I
should then look up the ws_row and ws_col fields, but that makes it way too
obvious what I'm doing there. Since a struct winsize just contains four
unsigned shorts, I replaced it with an array. And since all the values will
be much less than 32767, I further simplified the type to just short[].
A wonderful thing about ANSI graphics is that it produces nearly unintelligible
code. Consider the printf(3) spec to print a single space in a desired color:
"\x1B[%dm . I could have done something to further obfuscate it, but it's
already indistinguishable from line noise, so why bother?
There are lots of other minor obfuscations to make the code less obvious. For
example, I could have written the outer loop as while(1), but why write a 1
when I can calculate it from the return value of usleep(3) instead? And I
could have written usleep(80000), but usleep(79383) just looks so much
better. And so on.