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
There is an alternate version that the author provided but fixed in 2023 to
compile with modern systems and to allow one to reconfigure the constants X1,
X2, Y1 and Y2 (which were magic numbers). See Alternate
code below.
To use:
./prog
Try:
./prog
Try changing bounding box coordinates in the source to explore various regions of the fractal.
Alternate code:
The alternate code is included as prog.alt.c so you can more easily see the difference in what it might look like if the C was more recognisable and also to let you reconfigure the coordinates.
Alternate build:
make alt
If you wish to redefine the coordinates you can do so by defining X1, X2,
Y1 and/or Y2, which default to: -2, 1, -1.3 and 1.3 respectively.
For instance:
make clobber X1=-3 X2=2 Y1=-2.3 Y2=2.3 alt
You may pick and choose which ones to redefine.
Alternate use:
Use prog.alt as you would prog.
Alternate try:
./try.alt.sh
Judges' remarks:
We consider this entry a tribute to all "Abuse of the C preprocessor" and Mandelbrot fractal drawing entries we've seen over the years.
We liked the use of unary notation facilitated by variadic macros.
Author's remarks:
Portability
The application was written on a standard Ubuntu 14.04 and tested with gcc 4.9.1 and clang 3.5 on a 64 bit system (though this should not matter). The application makes no assumption regarding any system specific settings, and it only needs a console to run. The provided Makefile is just to have an easy compilation. I don't see any problems porting it to different compiler/system as long as it supports the C99 standard.
The application
The purpose of the application is mainly to illustrate the weird possibilities of the C preprocessor, rather than to be a full featured console mode Mandelbrot drawer. There are tools much better suited for drawing fractals.
The usage of recognizable elements from the C programming language in the application source code is intentionally kept to a bare minimum. If this phrase would not be true, the application would be the following:
double _[]={-2
,1,-1.3 ,1.3, 0, 0,0,0
,0 ,0,50, 80, 0,0,0 ,255
, 8,0}; int main (
int j) {if (j== 1 ){ if(
_[12] >_[10] )_[17]=1 ;} if
(_[13] >_[11 ] ||_[17]==1) return 1
;_[6] = _ [13] / _[11]*(_[1]-_[ 0])
+_[ 0]; _ [7]=_[12]/_[10]*(_[3]-_[2] )+_
[2];_[8]=_[9]=_[14]=0;l2:_[4]=_[8] * _ [8]
;_[ 5]= _ [9]*_[9];_[9]=2*_[8]*_[9]+ _[7
];_[8 ] = _ [ 4 ]-_[5]+_[6];_[14 ]++
;if((_ [14]< _ [15])&&(_[4]+ _[ 5]
<_[16 ])) goto l2; putchar(
" #@*+ "[( int) _[14]%
5 ]);_ [13 ] ++ ; main (
0) ;_[12]++; _[13] =0
;if(_ [17] !=1) putchar
(0xa); main(1);}
The application expects no parameters, the only way you can change the behaviour
is to modify the source code at the indicated location: the line
/* <-- Configure here: X1, X2, Y1, Y2 */ is intentionally not obfuscated so
that the adventurous programmer can manually modify the coordinates of the
fractal to be drawn on the screen.
Compiler warnings
Yes, unfortunately there are compiler warnings of the kind "initialization makes integer from pointer without a cast" but the provided Makefile automatically disables them.