Landon Curt Noll
7712db4a17
Given how problematic leading tabs in markdown files can be,
we have expanded all leading tabs in markdown files by:
```sh
find * -type f -name '*.md' -print |
while read -r file; do
rm -f "$file.tmp" ;
expand < "$file" > "$file.tmp" ;
mv -f -v "$file.tmp" "$file" ;
done
```
Given the previous changes to `bin/pandoc-wrapper.sh` and other recent
commits and recent pull requests, the were were **NO** changes to
any HTML files. This is a **good thing** as the expression goes.
No there are no leading tabs in any markdown files.
A check to catch any re-introduction of leading tabs
into any markdown file is on the way.
BTW: We do not have anything against leading tabs in files,
even though we have had to deal with their impact on forming
HTML from markdown files (as well as the calc source code).
It is just that this is one of those cases where tabs conflict
(sometimes caused by people wanting to change the classic
8-space tab model) with a desired outcome.
Perform `make www` to perform the above and test under macOS.
4.0 KiB
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.