Here are some of my productions created over the years. Most of them are works in progress. They are released under the ICS license: do whatever you want with them, but at your own risk. Executables are compressed with UPX.


GCC source + Win32 exe + details Spatial color quantization

Iteratively finds a palette and dithering for a given image. Based on the article “On spatial quantization of color images”, but the visual model is much more realistic.

GCC source + Win32 exe Procedural textures

Generates procedural 3D textures (two layers of modulated Perlin noise). Code originally from POV-Ray.


Intros are programs with tiny executable size, usually displaying an interesting realtime effect. The ones here are written in assembler and use the ancient COM executable format with all of DOS’ advantages and limitations. They run in Windows XP or older — use DOSBox elsewhere. To exit an intro, hold [Esc].

Also check out Pouët.net for more realtime eye-candy.

NASM source + DOS com Dírojed (Hole eater), 32 bytes

My demoscene debut: a simple cellular automaton, updating one pixel at a time. Optimized from T$’s original.

NASM source + DOS com Paralaxa, 32 bytes

Parallax planes creating an illusion of 3D. Also a non-escapable version with the planes warped according to a texture.

NASM source + DOS com Vycházka (Jaunt), 64 bytes

Another cellular automaton; rules vary with screen position. Gets more and more distorted.

NASM source + DOS com Slejvák (Downpour), 64 bytes

Rain! Randomly-placed vertical lines with heavy horizontal blur.

NASM source + DOS com Čtverečky (Little squares), 85 bytes

Rotozoomed texture with feedback creates chaotic spirals. Proof that the default MCGA palette can look stylish too.

NASM source + DOS com Výheň (Furnace), 99 bytes

Fire! Complex heat-propagating rules with pretty colors. Versions are named after chemicals.

NASM source + DOS com Mixér, 128 bytes

Radial lines with blur. The central eye slowly swallows the whole screen until only black, white and red remains.

NASM/MinGW source + DOS com + Win32 screensaver Symetrie (Symmetry), 256 bytes

A strange attractor randomly choosing among three Moebius transformations with changing parameters. Also a screensaver!

NASM source + DOS com Vlnky (Little waves), 256 bytes

Plasma-warped plasma with spatial- and time-propagated error diffusion and slowly changing palette.

NASM source + DOS com Puls, 256 bytes (YouTube)

Binary-search raycasting of an animated 3D scene.

NASM source + DOS com Difúze, 256 bytes (YouTube)

Gray-Scott reaction-diffusion with MIDI appergios playing in the background.

The following intros are playable. You have to lose to exit them.

NASM source + DOS com Shifticida, 32 bytes

Tiniest game ever. Press your [Shift] more vigorously than your opponent and crush him in a corner.

NASM source + DOS com 4is256, 256 bytes

A tetris game with scoring, increasing speed, fast dropping (for extra points) and funny controls. Beat my top score of 21787!


I like playing with graphical effects that might turn into intros someday. They usually use old-school software rendering, but are realtime on newer machines. Sources for MinGW are available on request (then need cleanup badly).

Recently I’ve ventured into GPU shader programming to learn how to make 1k and 4k intros.

Win32 exe + GCC source Boxplorer 1.02

GPU raymarcher of the Mandelbox fractal (needs SDL and a good graphics card). May compile in Linux and MacOS, too.

Win32 exe + screensaver Atraktor 1.1

Rotating strange attractors generated by my own formula. Leaked from my Deviantart account to freeware sites.

Win32 exe Difúze

Gray-Scott reaction-diffusion with radial blur. [P] resets, other keys change parameters. Needs a speedup.

Win32 exe + screensaver Puls

...waiting for backport from ASM...

Useful stuff

C headers Řrřola’s C headers

A bunch of header files to make my C programming easier. Used in other projects.

GCC source + data + Win32 exe org2xm

Converts the awesome music of Cave Story into the XM module format (suitable for trackers or Winamp).

font Coder’s Choice fonts 1.0

Monospaced Windows bitmap fonts for programming. Two widths are available: 7×11 and 6×11.

MSKLC sources + installer Řrřola’s keyboard layout 1.04

Hybrid Czech-English keyboard layout for programming. Can be used in Windows 2000 or newer.

C source + exe TGA downscaler

Downscales a 24-bit TGA image by the Lanczos3 filter in linear color space. Can process very large images.

College projects

These aren’t very useful on their own, but contain implementations of many interesting algorithms.

GCC source + Win32 exe Karhunen-Loève transform

Compresses grayscale images by finding the eigenfunctions of their 8×8 tiles. Something like JPEG, but tailored to the image.

GCC source + Win32 exe TrueSeer

Truecolor wavelet image compression with channel decorrelation and arithmetic coding. Everything can work losslessly.

Version 1 uses greedy wavelet packet transform and linear prediction of coefficients. Version 2 uses the bandelet transform — visually better for mid bitrates, but slow.

GCC source + Win32 exe Finite elements + matrix multiplication

Solves a partial differential equation on a regular 2D grid. Also, benchmarks show that dense matrices should be tiled for better cache coherency. Done for Numerical Mathematics.

GCC source + Win32 exe Dynamic time warping [training data]

Simple voice recognition — dynamic time warping over MFCC vectors. Trained for Czech digits… by me ;-)


Here you’ll find programs as old as 1998.

GCC source + Win32 exe Wolf

Very simple Wolfenstein-like engine hacked on a rainy afternoon. Uses the SDL.

DJGPP source + DOS exe + editor + levels Painball

Wireframe portal engine for an unfinished first-person shooter. Done in high school with my friend Martin Káldy (he made the kick-ass level editor). You’ll probably need DOSBox to run it.

BC++3.1 source + DOS exe PalLUT

A palette lookup table test. Did you know that StarCraft and Diablo II used 256 colors with tables like these? I think it’s cute.