2016-11-27, post № 148
art, haiku, poetry, #winter
First candle is lit,
Advent season is now here.
2016-11-27, post № 148
art, haiku, poetry, #winter
First candle is lit,
Advent season is now here.
2016-11-19, post № 147
art, haiku, mathematics, poetry, programming, Python, #prime
While you have no primes,
While you would like to know them.
If, if you could print…
2016-11-05, post № 146
brainfuck, programming, Python, #esoteric, #interpreter, #minimalism
Usually, programming languages are designed to be efficient, understandable and usable. Their concepts are well thought-out, giving the programmer powerful tools to create their application.
Esoteric programming languages have a slightly different aim. Instead of focusing on the product, they focus on the programmer’s journey and try new approaches to building a program.
One well-known esoteric programming language is Urban Müller’s brainfuck. It is a Turing-complete programming language — meaning that it could with infinite memory do what a Turing machine can do —, which practices extreme minimalism. The language knows of only eight characters (
The language’s usage is very similar to a Turing machine. Starting the program, the pointer is at cell zero and can be moved left (
<) or right (
>) by one cell.
The cells’ values are all starting at 𝟢, but can be either increased (
+) or decreased (
-) by one. Because the cells can only store one unsigned byte, adding one to 𝟤𝟧𝟧 yields in 𝟢 and subtracting one from 𝟢 yields in 𝟤𝟧𝟧.
Also, a loop is possible by using square brackets. An open square bracket (
[) starts a loop and a closed square bracket (
]) ends a loop. When the end of a loop is reached, the interpreter will jump back to its start if and only if the currently selected cell’s value is 𝟢. 
The only way to communicate with the user is to print the currently selected cell’s ASCII character to the screen (
.) and get a user input which will be stored in the currently selected cell as its ASCII value (
Because of its minimalistic design, writing an interpreter is not particularly hard. Listed below is the Python code of my interpreter, which I used to execute my own brainfuck “Hello World.” program (𝟣𝟣𝟪 characters).
Online interpreters include for example bf.doleczek.pl and sange.fi.
$ python brainfuck.py Hello World.
2016-10-31, post № 145
art, poetry, #horror, #purple cube, #sea, #story
2016-10-22, post № 144
art, codegolf, poetry, programming, Pygame, #character-sparse code, #characters, #space-efficient, #StackExchange
I recently  found a five year old StackExchange thread talking about a programming challenge to recreate the marvelously imaginative lyrics of ‘99 Bottles of Beer’. The song goes as follows (whole lyrics can be viewed below).
Of course, the real challenge is not to build a program that generates the lyrics but rather to do it with the least amount of characters . To achieve this goal, I tried out various strategies, all written in Python.
The first strategy is to join a string generated by a for loop (𝟤𝟨𝟥 characters).
a,b=" bottles of beer"," on the wall" c=a.replace("s","") print"\n".join([str(n)+a+b+", "+str(n)+a+"."+"\nTake one down and pass it around, "+str(n-1)+[a,c][n<3]+b+".\n"for n in range(99,1,-1)])+"\n1"+c+b+", 1"+c+".\nGo to the store and buy some more, 99"+a+b+"."
The second, less efficient strategy is to use a function and recursion (𝟤𝟩𝟦 characters).
a,b=" bottles of beer"," on the wall" c=a.replace("s","") def f(n): s="" if n>1: s="%d"%n+a+b+", %d"%n+a+".\nTake one down and pass it around, "+str(n-1)+[c,a][n>2]+b+".\n\n"+f(n-1) return s print f(99)+"1"+c+b+", 1"+c+".\nGo to the store and buy some more, 99"+a+b+"."
The third is a bit more character-efficient, using lambda functions and recursion (𝟤𝟩𝟢 characters).
a="%d bottle%s of beer" b=" on the wall" c=["","s"] f=lambda i:a%(i,c[i>1])+b+", "+a%(i,c[i>1])+".\nTake one down and pass it around, "+a%(i-1,c[i>2])+b+".\n\n" F=lambda i:f(i)+F(i-1)if i>0 else "" print F(99)[:-65]+"Go to the store and buy some more, "+a%(99,"s")+b+"."
The fourth, final and most space-efficient  strategy is to use a while loop (𝟤𝟧𝟢 characters).
a="%d bottle%s of beer" b=" on the wall" c=a+b+", "+a+"." i=99 s="" while i>1:s+=c%((i,"s")*2);i-=1;s+="\nTake one down and pass it around, "+a%(i,["","s"][i>1])+b+".\n\n" print s+c%(1,"",1,"")+"\nGo to the store and buy some more, "+a%(99,"s")+b+"."
2016-10-08, post № 143
Processing 3, programming, Python, #3D, #fractal, #three dimensions, #three-D, #three-dimensional
In July of 2015 I published my Menger Sponge post. As I said there, the true Menger Sponge is a three-dimensional object, but due to the lack of 3D-integration in Pygame, I only showed one of the six cube’s faces. The two-dimensional fractal is officially called Sierpiński carpet while the three-dimensional object is really called a Menger sponge.
To achieve the three-dimensional cube, I used Processing 3 together with its Python Mode.
The actual fractal is colored with a pseudo-randomly chosen color. All its smaller cubes then get a slight color shift. The cube rotates slowly, with a different speed on each of the three axes.
2016-09-24, post № 142
MicroPython, programming, Python 3, #micro, #microcontroller, #pyboard
Being a big fan of Python , I recently got a MicroPython Board.
MicroPython is a simple to use micro controller which runs Python 3. To put code onto it, you simple mount it as you would do with a USB flash drive, copy your
main.py to it and restart your MicroPython.
As a simple “Hello world.”-program, I wrote this counting script. Every time you press the built-in  button, it counts up by one. Using the four built-in LEDs and binary number representation, this counter can count from 𝟢 to 𝟣𝟧 and then wraps back.
2016-09-10, post № 141
curses, programming, Python, #animation, #bit, #bits, #falling bits, #hacker, #hacking, #Matrix, #screensaver
Recreating the famous falling bit effect from Matrix using python and curses.The individual bit strips are separate entities, falling to the bottom and then being moved up again with a different 𝑥 value. They also get a random speed between one and five deciseconds.
2016-09-03, post № 140
mathematics, programming, Pygame, Python, #3n+1, #three n plus one
The Collatz conjecture states that every positive integer 𝑘 > 𝟢 will — if you iteratively set 𝑘 to 𝑓 (𝑘) — result in 𝟣 (function shown beneath).
The graph beneath shows the path length of numbers from 𝟣 to 𝟣𝟢 𝟢𝟢𝟢. In this range, 𝟨 𝟣𝟩𝟢 is the number with the most steps, 𝟤𝟨𝟣.
2016-08-27, post № 139
curses, programming, Pygame, Python, #camera, #color depth, #low resolution, #shell image, #.si, #text-based images
Normally a shell lets you input via a text command and outputs via a text message . When using curses you can extend its capabilities and program for example games with limited graphics.
I wanted to go even further and built a Python script that — using Pygame’s camera module and curses — captures an image from an attached webcam (USB or built-in), transforms it and displays it on the shell.
Although both the resolution and the color depth are shrunk immensely, the resulting colored text on the shell often resembles the scene caught and has a nice visual effect.
There are two modes, camera and file viewer, which can be toggled by pressing ‘F1’. In camera mode you can see what the camera is seeing and snap a photo, which then will be saved to disk. In file viewer mode you can view the photos you took. The files will be saved in an
out/ directory located in the current Python file’s directory. Saved photos have the file extension
.si (“shell image”).
Unfortunately, Pygame’s camera module does neither work on Mac OS X nor on Windows. Thus this program is only properly usable under Linux  systems. You obviously also need a webcam or else you will not be able to take a picture.
.sifile (only in camera mode),
2016-08-20, post № 138
curses, games, programming, Python, #bag, #bag method, #Tetris
This game’s challenge is
to arrange the falling blocks.
Stay alive forever.
Jetris Console Edition is my second Tetris clone (see Jetris for the first one). It is programmed in Python and uses the curses module to display all its graphics on the shell.
Despite it running purely on the shell, I managed to eliminate any noticeable graphics update bugs. Furthermore the code to clear lines differs immensely from Jetris and actually works properly.
To enhance gameplay I implemented the so-called bag method. Instead of choosing pieces at random, a bag gets filled with all seven possible pieces. Each time you get a new piece, that piece gets randomly chosen out of the bag. If the bag is empty, it gets refilled. That way it is ensured that there will be no more than twelve pieces between two identical pieces (worst-case scenario). Also there will no more than four ‘S’ or ‘Z’ pieces in a row which makes the game fairer.
The pieces initially fall at one pps (pixel per second) and the game runs at twelve tps (ticks per seconds). Every ten cleared lines the speed increases by one tick or one twelfth of a second until it stays at the minimum speed, one twelfth of a second. 
The game’s clock is handled by a thread and graphics updates are made when they are needed (there are no fps).
To achieve the pieces blocky look I used two spaces and a color pair whose background color is the piece’s color. On the shell two fully filled characters look like a square.
You also have the option to change your key bindings — which get saved on disk —, pause the game and there is a high score list — which also gets saved on disk. The files are located where the Python code file resides.