John Tsiombikas' personal web site

[ about - hacks - articles ]

About

My name is John Tsiombikas (alternate spelling: Tsiompikas) and I'm a hacker. Most of the time I'm hacking on computer graphics, sometimes operating systems and kernel code, and lately a bit of electronics.

If you want to talk to me, drop me an email at nuclear@member.fsf.org (also here's a complete list of all my past and current email addresses). Send me only proper plain-text emails hard-wrapped at 72 columns, or prepare to meet my bit-bucket.

You may use my GPG key (fingerprint: 7911 86F0 D58B 5487 EB91 82D6 B4AF 109C 4174 CFF2) to send me encrypted messages. It's also available on public keyservers.

Other than this web page I've got a blog, some videos on youtube, a picassa photo album, and I post on twitter and identi.ca.

Support the Free Software Foundation, by becoming an FSF associate member

Hacks

Some of the following hacks are release-quality and useful, and some are quick&dirty hacks I happen to quite like. The lists under each category are not exhaustive, click on the top-level links for more hacks.

• Self-hosted
  • kernel - a simple UNIX kernel for x86 PCs
  • cl-ray - interactive GPU (OpenCL) raytracer for polygon mesh scenes
  • metasurf - implicit surface polygonization (isosurface extraction) library
  • libdrawtext - OpenGL text rendering library
  • libpsys - particle system
  • dsys2 - event sequencing library designed demoscene productions
  • rbtree - balanced binary search tree (left-leaning red-black tree) library
  • imtk - immediate-mode GUI toolkit for OpenGL programs
  • vpost (and plugins) - video processing with OpenGL code
  • stereoview - stereoscopic OpenGL image viewer
  • stereoplay - stereoscopic OpenGL video player
  • simply-gl - cross-platform glut-like event handling and OpenGL context creation
  • rayfract - real-time GPU (GLSL) julia quaternion fractal raytracer
  • webgl tools - javascript "libraries" to make writting WebGL code simpler
  • webgl hacks - random webgl hacks
  • xresize - resize X11 screen using either the xr&r or the xf86vidmode extension
  • wmfreqview - window-maker dockapp showing a graph of processor frequency (frequency scaling) over time.
• Hosted at googlecode
  • s-ray - photorealistic renderer using the photon mapping algorithm
  • henge - simple C++ OpenGL 3D engine
  • stereowrap - stereoscopic OpenGL wrapper for non-stereo-capable systems
  • ubertk - GUI toolkit for graphics applications
  • kdtree - simple C library for working with kd-trees
  • frapix - framerate monitoring, limiter, and screen capture for UNIX OpenGL programs
  • drippy - datafile ripper
  • linuxtrack-wine - glue between the linuxtrack head-tracking system and windows applications running through wine
• Hosted at sourceforge
  • graphics programmer's toolbox - loose collection of graphics-related libraries
  • spacenav - 6dof device userspace driver and sdk
  • libfixgl - fixed point OpenGL implementation
  • win-x-move - move and resize windows by alt-dragging for ms windows
• Old projects
  • 3dengfx - cross-platform OpenGL 3D engine
• Demoscene projects
  • mindflush / mlfc - demo, 2nd at pixelshow 2007 (cross-platform, opengl) [youtube video]
  • pixelshow2007 invitro / the lab - invitation for the pixelshow 2007 demoparty (cross-platform, opengl)
  • softy / mlfc - demo, 4th at the coder.gr x-mass 2006 compo (cross-platform, software rendering) [youtube video]
  • summerhack / the lab - demo, released in 2005 (cross-platform, opengl) [youtube video]
  • eternal / the lab - demo, 3rd at react 2004 (gnu/linux, opengl)
  • wedtroid / the lab & quadra - wedtro for cybernoid's wedding, released in 2003 (windows, direct3d 8)
  • absence / the lab - demo, 3rd at react 2003 (windows direct3d 8)

In rare occasions I write code for other people's projects. The only recurring one is freeglut.

Articles

Here's a list of articles I've written (apart from whatever is on my blog):

• Kernel programming from scratch - an ongoing series of articles for the linux inside magazine about writing a rudimentary operating system kernel from scratch. Currently in greek only.
• Fast & easy fractals with a pixel shader - A tutorial on calculating the mandelbrot and julia fractals directly on the GPU with the OpenGL shading language.
• Preparing for GBA development - A small article guiding you through the process of setting up the necessary tools for GameBoy Advance development.
• Pointers explained - A clean and concise explanation of pointers in C and C++ for beginners, who often have trouble understanding how to use them.
• Shadow volumes tutorial - Tutorial on the shadow volume (stencil shadows) algorithm.

I had written some more for the now defunct demoscene.gr web site. I'll try to collect them locally and post them here soon.